Electrical connectivity of die to a host substrate
09831168 · 2017-11-28
Assignee
Inventors
Cpc classification
H01L2924/19105
ELECTRICITY
H01L2224/114
ELECTRICITY
H01L2224/0401
ELECTRICITY
H01L23/4824
ELECTRICITY
H01L2224/131
ELECTRICITY
H02M3/33592
ELECTRICITY
H01L23/498
ELECTRICITY
H01L2924/13091
ELECTRICITY
H01L21/486
ELECTRICITY
H02M3/33576
ELECTRICITY
H01L2224/131
ELECTRICITY
H01L2224/16227
ELECTRICITY
Y02B70/10
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
H01L21/768
ELECTRICITY
H01L27/088
ELECTRICITY
H01L2924/00014
ELECTRICITY
H01L2224/1415
ELECTRICITY
H01L2224/81191
ELECTRICITY
H02M3/33507
ELECTRICITY
H01L2224/05548
ELECTRICITY
H01L2224/17106
ELECTRICITY
H01L2224/14104
ELECTRICITY
H01L23/50
ELECTRICITY
H01L2924/00014
ELECTRICITY
H01L23/49861
ELECTRICITY
H01L2224/16225
ELECTRICITY
H01L24/02
ELECTRICITY
H01L2224/114
ELECTRICITY
H02M3/1588
ELECTRICITY
International classification
H01L23/498
ELECTRICITY
H01L27/088
ELECTRICITY
H01L21/48
ELECTRICITY
H01L29/423
ELECTRICITY
H01L23/50
ELECTRICITY
H01L23/482
ELECTRICITY
H01L27/06
ELECTRICITY
Abstract
According to example configurations herein, an apparatus comprises a die and a host substrate. The die can include a first transistor and a second transistor. A surface of the die includes multiple conductive elements disposed thereon. The multiple conductive elements on the surface are electrically coupled to respective nodes of the first transistor and the second transistor. Prior to assembly, the first transistor and second transistor are electrically isolated from each other. During assembly, the surface of the die including the respective conductive elements is mounted on a facing of the host substrate. Accordingly, a die including multiple independent transistors can be flipped and mounted to a respective host substrate such as printed circuit board, lead frame, etc.
Claims
1. An apparatus comprising: a die comprising: a first transistor, a second transistor, and a surface including multiple conductive elements thereon, the multiple conductive elements on the surface electrically coupled to respective nodes of the first transistor and the second transistor; and a host substrate, the surface of the die mounted on a face of the host substrate, the host substrate electrically connecting the first transistor and the second transistor in series; wherein the first transistor is a control switch of a switching power supply circuit; wherein the second transistor is a synchronous switch of the switching power supply circuit; wherein the control switch is a first single field effect transistor disposed in the die; wherein the synchronous switch is a second single field effect transistor disposed in the die; and wherein the multiple conductive elements on the surface of the die includes: a first gate conductive element coupled to a gate region of the first field effect transistor, a first source conductive element coupled to a source region of the first field effect transistor, a first drain conductive element coupled to a drain region of the first field effect transistor, a second gate conductive element coupled to a gate region of the second field effect transistor, a second source conductive element coupled to a source region of the second field effect transistor, and a second drain conductive element coupled to a drain region of the second field effect transistor.
2. The apparatus as in claim 1, wherein the surface of the die is mounted directly on the host substrate.
3. The apparatus as in claim 1, wherein the surface of the die is directly coupled to an electronic circuit package, the electronic circuit package providing connectivity between the respective nodes and the face of the host substrate.
4. The apparatus as in claim 1, wherein the first transistor is electrically isolated from the second transistor prior to mounting of the die to the face of the host substrate.
5. The apparatus as in claim 4, wherein at least one conductive path disposed on the host substrate provides electrical connectivity between the first transistor and the second transistor.
6. The apparatus as in claim 1 further comprising: an inductor element, a first node of the inductor element electrically connected to the source region of the first transistor and the drain region of the second transistor; and a controller, the controller receiving feedback of an output voltage produced at a second node of the inductor element, the controller driving the gate region of the first transistor and the gate region of the second transistor to produce the output voltage within a desired range.
7. The apparatus as in claim 6, wherein the host substrate electrically connects an input voltage to the drain region of the first transistor.
8. The apparatus as in claim 7, wherein the first transistor comprises a first set of multiple transistor components connected in parallel; and wherein the second transistor comprises a second set of multiple transistor components connected in parallel.
9. The apparatus as in claim 1, wherein the first transistor comprises a first set of multiple transistor components connected in parallel; and wherein the second transistor comprises a second set of multiple transistor components connected in parallel.
10. The apparatus as in claim 1, wherein the first transistor is electrically coupled to the second transistor via a conductive path disposed in the die.
11. The apparatus as in claim 1, wherein the die includes a controller, nodes of the controller electrically coupled to conductive paths on the host substrate; and wherein the controller is configured to control operational states of the first transistor and the second transistor via control signals transmitted over the conductive paths.
12. The apparatus as in claim 1, wherein the first transistor is a first single lateral field effect transistor disposed in the die; and wherein the second transistor is a second single lateral field effect transistor disposed in the die.
13. The apparatus as in claim 1 further comprising: an inductor, the inductor including a first terminal and a second terminal, the first terminal of the inductor electrically coupled to the conductive path in the host substrate providing circuit connectivity between the source region of the first transistor and the drain region of the second transistor, a second terminal of the inductor configured to produce an output voltage to power a load.
14. The apparatus as in claim 1, wherein the host substrate provides an electrical connection between the source node of the first transistor and the drain node of the second transistor.
15. The apparatus as in claim 14, wherein the host substrate electrically couples the source node of the first transistor and the drain node of the second transistor to an inductor circuit of a power supply.
16. The apparatus as in claim 1, wherein the host substrate couples the first transistor and the second transistor in series between a first reference voltage and a second reference voltage.
17. The apparatus as in claim 1, wherein the host substrate on which the die is mounted electrically couples the first transistor and the second transistor in series between a first reference voltage and a second reference voltage; wherein the first reference voltage is electrically connected to the drain region of the first transistor; and wherein the second reference voltage is electrically connected to the source region of the second transistor.
18. The apparatus as in claim 1 further comprising: a first pad disposed on the face of the host substrate; a second pad disposed on the face of the host substrate; and a conductive path extending between the first pad and the second pad, the first source conductive element in contact with the first pad, the second drain conductive element in contact with the second pad.
19. The apparatus as in claim 18, wherein the first gate conductive element, the first drain conductive element, and the first source conductive element are disposed in a first sequence on the surface of the die; wherein the second gate conductive element, the second drain conductive element, and the second source conductive element are disposed in a second sequence on the surface of the die; and wherein the first sequence is parallel to the second sequence.
20. A method comprising: receiving a die, the die comprising: a first transistor, a second transistor, and a surface including multiple conductive elements thereon, the multiple conductive elements on the surface electrically coupled to respective nodes of the first transistor and the second transistor; and mounting a surface of the die to a face of the host substrate to electrically connect the first transistor and the second transistor in series; wherein the first transistor is a control switch of a switching power supply circuit; wherein the second transistor is a synchronous switch of the switching power supply circuit; wherein the control switch is a first single field effect transistor disposed in the die; wherein the synchronous switch is a second single field effect transistor disposed in the die; and wherein the multiple conductive elements on the surface of the die includes: a first gate conductive element coupled to a gate node of the first field effect transistor, a first source conductive element coupled to a source node of the first field effect transistor, a first drain conductive element coupled to a drain node of the first field effect transistor, a second gate conductive element coupled to a gate node of the second field effect transistor, a second source conductive element coupled to a source node of the second field effect transistor, and a second drain conductive element coupled to a drain node of the second field effect transistor.
21. The method as in claim 20 further comprising: mounting the surface of the die directly onto the host substrate.
22. The method as in claim 20, wherein the surface of the die is directly coupled to an electronic circuit package, the method further comprising: mounting the electronic circuit package to the host substrate, the electronic circuit package providing connectivity between the respective nodes and the face of the host substrate.
23. The method as in claim 20, wherein the first transistor is electrically isolated from the second transistor prior to mounting of the die to the face of the host substrate, the method further comprising: mounting the die to the face of the host substrate to provide electrical connectivity between the first transistor and the second transistor via at least one conductive path disposed on the host substrate.
24. The method as in claim 20, further comprising: via a first conductive path in the host substrate, providing an electrical connection between a source node of the first transistor and the drain node of the second transistor; and via a second conductive path in the host substrate, electrically connecting an input voltage to a source node of the first transistor.
25. The method as in claim 24 further comprising: electrically connecting the source node of the first transistor and the drain node of the second transistor to a first node of an inductor element; and electrically connecting a controller to the gate node of the first transistor and the gate node of the second transistor, the controller configured to produce an output voltage at a second node of the inductor to be within a desired range.
26. The method as in claim 20, wherein the die includes a controller circuit, the method further comprising: via conductive paths in the host substrate, electrically coupling the respective nodes of the die to the controller, the controller operable to control operational states of the first transistor and the second transistor via control signals transmitted over the conductive paths.
27. The method as in claim 20, wherein mounting the surface of the die to the face of the host substrate provides an electrical connection between the source node of the first transistor and the drain node of the second transistor.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The foregoing and other objects, features, and advantages of the invention will be apparent from the following more particular description of preferred embodiments herein, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, with emphasis instead being placed upon illustrating the embodiments, principles, concepts, etc.
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DETAILED DESCRIPTION
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(24) As shown, one embodiment herein includes a leadframe device 190 comprising a connection interface 110-1. The connection interface 110-1 can be configured for electrically attaching an electrical circuit 120 to the leadframe device 190.
(25) The leadframe device 190 includes a conductive path 140-1. The conductive path 140-1 has a contact region on facing 150-1 in the leadframe device 190 and provides an electrical connection between electrical node 125-1 of the electrical circuit 120 and electrical node 125-2 of the electrical circuit 120.
(26) Prior to making the connection between the electrical circuit 120 and the contact region of the conductive path 140 in the leadframe device 190, the electrical node 125-2 and the electrical node 125-1 are electrically isolated from each other. In other words, they are not electrically connected with respect to each other by virtue of a metal interconnect on the electrical circuit 120.
(27) Subsequent to making connection of the electrical circuit 120 with the leadframe device 190 via conductive bridge elements 130, the conductive path 140-1 of the leadframe device 190 electrically connects the electrical node 125-2 and the electrical node 125-1 together.
(28) In one embodiment, the conductive bridge element 130-1 electrically connects the electrical node 125-1 to the conductive path 140-1. The conductive bridge element 130-2 electrically connects the electrical node 125-2 to the conductive path 140-1.
(29) The conductive bridge element 130 can take on any of a number of different forms. For example, in one embodiment, the conductive bridge element 130 is a pillar made of conductive material.
(30) The pillar or other suitably shaped bridge can be formed on a surface of the electrical circuit 120 by depositing a metal layer on the electrical circuit 120 and then etching away a portion of the deposited metal layer to produce, for example, one or more pillars. In one embodiment, the pillars are plated up after a mask is applied. This is a selective plating process as opposed to a selective etching. Either approach could be used.
(31) A conductive material such as solder can be used to connect the pillar (conductive bridge element) to the conductive path 140-2. In one embodiment, the conductive bridge elements 130 are made from copper, although any suitable metal can be used to provide such functionality.
(32) Thus, in an example embodiment, the electrical node 125-1 can be electrically coupled to a pillar of conductive material for connecting a first portion of the electrical circuit 120 to the conductive path 140-1 of the leadframe device 190. The electrical node 125-2 can be electrically connected to a second pillar of conductive material for connecting a second portion of the electrical circuit 120 to the conductive path 140-1 of the leadframe device 190. Again, the conductive bridge elements 130 can be made of copper or other suitable material.
(33) According to other alternative embodiments, note that the conductive bridge elements 130 can be solder balls that connect respective electrical nodes 125 of the electrical circuit 120 to the conductive path 140-1. As mentioned, any suitable conductive material can be used to provide connectivity between the electrical nodes 125 and the conductive path 140-1.
(34) Note that in an example embodiment the electrical circuit 120 is an integrated circuit such as a semiconductor chip. The electrical nodes 125 can emanate from a single electrical circuit 120 fabricated on a common semiconductor substrate. The electrical circuit 120 can thus be a semiconductor chip cut from a wafer.
(35) In alternative embodiments, the electrical circuit 120 can include a number of semiconductor chips that are packaged into the same leadframe package 100.
(36) Accordingly, embodiments herein include a way of utilizing a leadframe device 190 to provide off-chip connectivity between electrical nodes 125 of an electrical circuit 120 in lieu of having to provide such connectivity at, for example, a metal interconnect layer of the integrated circuit device.
(37) As shown, the leadframe device 190 can also include a second connection interface 110-1 for attaching the leadframe device 190 to a substrate 170 such as a printed circuit board, flex-board, etc. Conductive bridge elements 160 such as conductive bridge element 160-1, conductive bridge element 160-2, conductive bridge element 160-3, and conductive bridge element 160-4 can provide electrical connectivity between the contact elements 145 and a respective one or more traces of the substrate 170. In one embodiment, each of the contact elements 145 is a conductive surface pad of the leadframe device 190 that is electrically attached to the substrate 170 via a conductive bridge element 160 such as solder.
(38) The second connection interface 110-2 of the leadframe device 190 can include one or more contact elements 145 (e.g., contact element 145-1, contact element 145-2, contact element 145-3, contact element 145-4) for electrically coupling the conductive path 190 of the leadframe device 190 to the substrate 170. In other words, according to one embodiment, the conductive path 140-1 can include multiple contact elements 145 for electrically connecting the conductive path 140-1 to the substrate 170.
(39) As shown, the contact elements 145 can be separated from each other via electrically non-conductive material such as a plastic filler of the leadframe package 100. The cross-hatched region indicates non-conductive material between the contact elements 145.
(40) Although any reasonable configuration is possible, according to one embodiment, the first connection interface 110-1 resides on a first facing 150-1 of the leadframe device 190 and the second connectivity interface 110-2 resides on a second facing 150-2 of the leadframe device 190.
(41) By way of a non-limiting example, the first facing 150-1 and the second facing 150-2 of the leadframe device 190 can be disposed on opposite sides of the leadframe device 190 with respect to each other, adjacent sides of the leadframe, same side of the leadframe, etc.
(42) One way to produce the leadframe device 190 is to start out with a slab of metal such as copper of appropriate thickness. The copper can be etched or machined to remove metal between the conductive paths 140 so that each of the conductive paths 140 are electrically independent of each other. In other words, according to one embodiment, the conductive paths 140 in leadframe device 190 are not connected to each other.
(43) Further machining can be performed at axial ends of the conductive paths 145 to fit the conductive paths 140 within the leadframe device 190. Since it may be desirable to have spaced surfaces as in
(44) Note that the inclusion of contact elements 145 on each of one or more of the conductive paths 140 is shown by way of non-limiting example only and that a respective conductive path need include a surface in which to attach to a host substrate 170. Accordingly, the respective conductive path can be used as a way of connecting nodes of electrical circuit 120 at a layer other than in a metalization layer of an integrated circuit. In this latter embodiment, when the leadframe device 190 is attached to a host substrate 170, the respective conductive path does not attach to the substrate.
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(46) As shown, the exposed side of electrical circuit 120 having electrical nodes 125 (e.g., electrical node 125-1, electrical node 125-2, etc.) is attached to the facing 150-1 of the leadframe device 190.
(47) In one embodiment, the electrical circuit 120 is a planar-shaped device (such as an integrated circuit, semiconductor device, etc.) including multiple circuits 210 (e.g., circuit 210-1, circuit 210-2, circuit 210-3, circuit 210-4, circuit 210-5, circuit 210-6) spread about a surface of the electrical circuit 120 (e.g., planar shaped device).
(48) A size associated with leadframe device 190 and corresponding electrical circuit 120 is highly scalable. For example, a number of rows and/or columns of circuits 210 residing on electrical circuit 120 can be varied to create switches having different sinking/sourcing capabilities. In such embodiments when the row and/or columns of circuits 210 is adjusted, the size of leadframe device 190 and number of conductive paths 140 in the leadframe device 190 can be adjusted to match the number of rows and columns of circuits 210 of electrical circuit 120. An example of adjusting rows and columns circuits 210 is shown and discussed with respect to
(49) Referring again to
(50) In one embodiment, each of the circuits 210 is a switch circuit as will be discussed later in this specification. Connectivity of the circuits 210 with respect to the conductive paths 140 as described herein connects the circuits 210 in parallel. As mentioned, contact elements of the conductive paths (e.g., surfaces on facing 150-2 of leadframe device 190 provide connectivity with respect to a substrate such as a printed circuit board or other interconnecting device.
(51) The conductive paths 140 (e.g., conductive path 140-1, conductive path 140-2, conductive path 140-3, conductive path 140-4, etc.) can provide connectivity between the multiple electrically independent circuits 210 and, optionally, through the leadframe device 190 to the substrate 170. For example, as shown, the facing of electrical circuit 120 can be pressed or moved into communication of the facing 150-1 of the leadframe device 190 to connect the electrical nodes 125 to corresponding locations on the conductive paths 140.
(52) More specifically, when electrical circuit 120 is moved into communication with facing 150-1, electrical node 125-2 (e.g., source node S.sub.11) of circuit 210-1 comes in contact with the location labeled S.sub.11 on conductive path 140-1; electrical node 125-1 (e.g., source node S.sub.12) of circuit 210-2 comes in contact with the location labeled S.sub.12 on conductive path 140-1; electrical node labeled source node S.sub.13 in circuit 210-3 comes in contact with the location labeled S.sub.13 on conductive path 140-1; and so on. Thus, the conductive path 140-1 of leadframe device 190 can provide “off-chip” connectivity with respect to a first set of electrical nodes in the electrical circuit 120.
(53) In accordance with the above embodiment, when electrical circuit 120 is moved in communication with facing 150-1, electrical node labeled drain node D.sub.11 of circuit 210-1 comes in contact with the location labeled D.sub.11 on conductive path 140-2; electrical node labeled drain node D.sub.12 of circuit 210-2 comes in contact with the location labeled D.sub.12 on conductive path 140-2; electrical node labeled drain node D.sub.13 in circuit 210-3 comes in contact with the location labeled D.sub.13 on conductive path 140-1; and so on. Thus, the conductive path 140-2 of leadframe device 190 can be configured to provide off-chip connectivity with respect to a second set of electrical nodes in the electrical circuit 120.
(54) Additionally, when electrical circuit 120 is moved in communication with facing 150-1, electrical node labeled source node S.sub.21) of circuit 210-4 comes in contact with the location labeled S.sub.21 on conductive path 140-3; electrical node labeled source node S.sub.22 in circuit 210-5 comes in contact with the location labeled S.sub.22 on conductive path 140-3; electrical node labeled source node S.sub.23 in circuit 210-6 comes in contact with the location labeled S.sub.23 on conductive path 140-3; and so on. Thus, the conductive path 140-3 of leadframe device 190 can provide “off-chip” connectivity with respect to a third set of electrical nodes in the electrical circuit 120.
(55) Additionally, when electrical circuit 120 is seated onto facing 150-1, electrical node labeled drain node D.sub.21 of circuit 210-4 comes in contact with the location labeled D.sub.21 on conductive path 140-4; electrical node labeled drain node D.sub.22 of circuit 210-5 comes in contact with the location labeled D.sub.22 on conductive path 140-4; electrical node labeled drain node D.sub.23 in circuit 210-6 comes in contact with the location labeled D.sub.23 on conductive path 140-4; and so on. Thus, the conductive path 140-4 of leadframe device 190 can be configured to provide off-chip connectivity with respect to a fourth set of electrical nodes in the electrical circuit 120.
(56) In further embodiments, it can be seen that at least a portion of each respective conductive path 140 in the leadframe device 190 can be substantially orthogonal with respect to a plane of the planar-shaped device (e.g., electrical circuit 120) on which the multiple circuits 210 reside.
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(59) In one embodiment, each circuit 210 includes a respective array of field effect transistors in an integrated circuit that are connected in parallel to each other of to form a switch circuit tile (e.g., circuit 210). As previously discussed, the switch circuit tiles each can include two electrical nodes (e.g., a source node and drain node) that connect to respective conductive paths 140. The common gates of circuit 210 can connect to control driver 410.
(60) For example, electrical circuit 120 can include a control driver 410. In one embodiment, the control driver 410 produces a set of gate control signals that are used to drive the gates of each respective circuit 210. In a further example embodiment, the gate control signals are formed in one or more metalization layer of a semiconductor device on which the respective switch tiles are formed. The electrical circuit 120 can include metalization to provide connectivity amongst the transistors within an array in the tile.
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(62) Embodiments herein can include fabricating multiple circuits 210 on a respective wafer 495 such as that shown in
(63) Of course, the leadframe device can vary in size and shape as well to accommodate the different sized circuits 120. For applications requiring more robust switching functionality, the package also can be adjusted in size to accommodate larger or smaller electrical circuits 120. Conversely, for applications requiring less robust switching functionality, the package can be larger to accommodate larger electrical circuits 120. As previously discussed, the leadframe device 190 is highly modular and scalable based on sizing and/or spacing of: conductive paths 140, circuits 210, circuit 120, source connections and drain connections on circuits 210, etc. In one embodiment, the sizing includes adding/deleting rows and/or columns of a standard size of circuits 210 (e.g., a field effect transistor array) to produce a family of devices having different capabilities.
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(65) As shown, the example electrical circuit 210-1 can include an array of transistors 520 such as field effect transistors. The array of transistors 520 can include transistor 520-1, transistor 520-2, transistor 520-3, transistor 520-4, transistor 520-5, transistor 520-6, transistor 520-7, transistor 520-8, transistor 520-9, transistor 520-10, etc.
(66) As mentioned above, the electrical circuit 210 can be one of multiple circuits on a respective single integrated circuit substrate. Via metalization in the integrated circuit, the gate nodes, source nodes, and drain nodes of the transistors 520 can be connected to each other.
(67) More specifically, via connectivity such as via metalization in an integrated circuit, the source node of transistor 520-1 can be connected to each of the source nodes of transistor 520-2, 520-3, 520-4, etc.; the source node of transistor 520-2 can be connected to each of the source nodes of transistor 520-1, 520-3, 520-4, etc.; the source node of transistor 520-3 can be connected to each of the source nodes of transistor 520-1, 520-2, 520-4, etc.; and so on.
(68) Via additional connectivity such as metalization in an integrated circuit, the drain node of transistor 520-1 can be connected to each of the drain nodes of transistor 520-2, transistor 520-3, transistor 520-4, etc.; the drain node of transistor 520-2 can be connected to each of the drain nodes of transistor 520-1, transistor 520-3, transistor 520-4, etc.; the drain node of transistor 520-3 can be connected to each of the drain nodes of transistor 520-1, 520-2, 520-4, etc.; and so on. Thus, in one embodiment, the array of transistors 520 can be interconnected to form a single functional transistor circuit having a common source node (e.g., node S.sub.11) and common drain node (e.g., node D.sub.11). In such an embodiment, the source node of each transistor 520 can be connected to common node S.sub.11, the drain node of each transistor 520 can be connected to communication drain node D.sub.11.
(69) As previously discussed, each of the common drain node D.sub.11 and common source node S.sub.11 are independent of each other and (prior to packaging in leadframe device 190) may be independent of other common source nodes and common drain nodes of other electrical circuits 210. The gate node of each transistor 520 of circuit 210-1 can tie to a common point and be controlled by a common gate signal. As mentioned, the gates can be connected with each other via and interconnect such as metalization in an integrated circuit.
(70) As previously discussed, the metal layer of electrical circuit 120 can include gate control signals from control driver 410 to each of the circuits 210. Creating paths for the gate control signals can be substantially easier according to embodiments herein because the conductive paths 140 in the leadframe device 190 provide connectivity amongst the circuits 210 in lieu of metalization in an integrated circuit. Thus, control signals such as gate control signals or other control signals can be laid out between tiles (e.g., circuits 210) and thus not interfere with the interconnectivity layer disposed over the array of transistors in each circuit 210.
(71) As shown, the spacing and/or widths of conductive paths can be selected depending on a spacing of the respective sources and drains of each circuit 210. For example, the spacing between conductive path 140-1 and conductive path 140-2 depends on locations of sources and drain connections on respective circuits 210-1, 210-2, 210-3, etc. Thus, if each circuit 210 is designed to include a larger sized array (e.g., more rows and/or columns of transistors) or circuit 210, the spacing of the conductive paths 140-1 and conductive path 140-2 can be increased to account for a respective larger spacing between respective sources and drains of circuits 210. Conversely, if the size and/or number of transistors in the circuits 210 is reduced, the respective source connections and drain connections of circuits 210 will be closer together. In this latter case, a spacing and/or widths of conductive paths 140-1 and 140-2 also can be adjusted or reduced to account for the change in size of the circuits 210.
(72) A spacing of the conductive paths 140 can be selected. In such a case, the size of circuits 210 and/or spacing of the sources and drain connections on each circuit 210 can be adjusted to ensure that the source and drain connections of each circuit 210 lines up with a respective conductive path 140 of leadframe device 190. Accordingly, embodiments herein include a highly scalable leadframe device 190.
(73) As discussed herein,
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(75) The impedance values A, B, C, D, E, F, G, H, I, J, K, L, M, etc. represent the impedances of conductive links (e.g., metalization layers in an integrated circuit) between each of the transistors 520. The connectivity within the electrical circuit (and each of the other electrical circuits 210) can be configured such that the total impedance path for any transistor is within a tolerance value such as within, for example, 20%. In other words, the legs of the paths can be within a nominal value+/−10 percent.
(76) Assume in the present example that the impedance values A, B, C, D, E, F, G, H, I, J, K, L, M, etc. represent an impedance of approximately 12.5 milliohms each. Note that the value of 12.5 milliohms is shown by way of non-limiting example only. The value may be different depending on the application.
(77) The impedance associated with transistor 520-2 between node D.sub.11 and node S.sub.11 includes a sum of impedance D (approximately 12.5 milliohms), impedance B (approximately 12.5 milliohms), and impedance C (approximately 12.5 milliohms). Assume in this example that the impedance between node D.sub.11 and transistor 520-1 is negligible. Thus, the total impedance path for transistor 520-2 (not including the transistor itself) is approximately 45 milliohms.
(78) In furtherance of this example, the impedance associated with transistor 520-2 between node D.sub.11 and node S.sub.11 includes a sum of impedance D (approximately 12.5 milliohms), impedance B (approximately 12.5 milliohms), and impedance C (approximately 12.5 milliohms). Thus, the total impedance path for transistor 520-2 (not including the transistor itself) is approximately 45 milliohms.
(79) The impedance associated with transistor 520-3 between node D.sub.11 and node S.sub.11 includes a sum of impedance D (approximately 12.5 milliohms), impedance E (approximately 12.5 milliohms), and impedance C (approximately 12.5 milliohms). Thus, the total impedance path for transistor 520-3 (not including the transistor itself) is approximately 45 milliohms.
(80) The impedance associated with transistor 520-4 between node D.sub.11 and node S.sub.11 includes a sum of impedance D (approximately 12.5 milliohms), impedance E (approximately 12.5 milliohms), and impedance F (approximately 12.5 milliohms). Assuming that the impedance between node S.sub.11 and transistor 520-4 is negligible, the total impedance path for transistor 520-4 (not including the transistor itself) is approximately 45 milliohms.
(81) In a similar manner, the impedance path values for each of transistors 520-5, 520-6, 520-7, 520-8, etc. are each approximately equal to 45 milliohms as well.
(82) Providing balanced path impedance interconnectivity in this manner is useful because the burden of providing isolation/coupling is more equally shared amongst the transistors 520. Thus, no single one of group of transistors is unduly stressed under high current sinking or sourcing conditions.
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(84) According to this example embodiment, only portions of the conductive paths 140 are exposed on a respective surface of the leadframe device 190. For example, contact element 145-1 and contact element 145-2 (rather than a whole length of the conductive path 140-1) are exposed on a bottom surface of the leadframe device 190 for attaching to a host such as printed circuit board; contact element 345-1 and contact element 345-2 (rather than a whole length of the conductive path 140-2) are exposed on a bottom surface of the leadframe device 190 for attaching to a host such as printed circuit board; and so on.
(85) The checkerboard like pattern of connection interface 150-2 reduces the likelihood, during mounting of the leadframe device 190 to a host, such as a printed circuit board, that a stray piece of wire, solder, conductive matter, etc. will accidentally form between the effective pads (e.g., contact elements) of the leadframe device 190.
(86) Note that additional pads 850 and corresponding conductive paths of the leadframe device 190 can provide connectivity with respect to the additional circuitry of the electrical circuit 120. For example, the pads 850 can provide conductive pathways form a printed circuit board on which the leadframe device 190 resides and gate driver or related circuitry of electrical circuit 120.
(87)
(88) As previously discussed, each of circuits 210 can be configured by interconnecting an array of field effect transistors to produce a respective field effect transistor switch circuit. Thus, as previously discussed, circuit 210-1 can be a first field effect transistor switch circuit, circuit 210-2 can be a second field effect transistor switch circuit, circuit 210-3 can be a third field effect transistor switch circuit, circuit 210-4 can be a fourth field effect transistor switch circuit, circuit 210-5 can be a fifth field effect transistor switch circuit, circuit 210-6 can be a sixth field effect transistor switch circuit, circuit 210-7 can be a seventh field effect transistor switch circuit, circuit 210-8 can be an eighth field effect transistor switch circuit, and so on.
(89) As shown, and as previously discussed, the circuits 210 of electrical circuit 120 reside at a topmost level (e.g., connection interface 110-1) of the transparent view. At connection interface 110-1 (see also
(90) In a similar manner as shown, source node of circuit 210-5 connects to conductive path 140-3; source node of circuit 210-6 connects to conductive path 140-3; source node of circuit 210-7 connects to conductive path 140-3; and so on. Drain node of circuit 210-5 connects to conductive path 140-4; drain node of circuit 210-6 connects to conductive path 140-4; drain node of circuit 210-7 connects to conductive path 140-4; and so on.
(91) Connection interface 110-2 provides connectivity between the contact elements (cross-hatched regions of conductive paths 140) of leadframe device 190 and the circuit board or substrate on which traces 950 reside. Conductive path 140-1 includes contact elements 145-1 and 145-2 for connecting to printed circuit board trace 950-1; Conductive path 140-2 includes contact elements 345-1 and 345-2 for connecting to printed circuit board trace 950-2; and so on.
(92) In a similar manner, conductive path 140-3 includes contact elements that connect to printed circuit board trace 950-1. Conductive path 140-4 includes contact elements that connect to printed circuit board trace 950-2. Conductive path 140-5 includes contact elements that connect to printed circuit board trace 950-1. Conductive path 140-6 includes contact elements that connect to printed circuit board trace 950-2.
(93) Accordingly, the source nodes (as shown in
(94) Each of the conductive paths 140 can be electrically isolated from each other until connected to a host substrate. After forming a physical connection between the leadframe device 190 and host as discussed above, the conductive paths 140-1, 140-3, 140-5 become electrically connected via trace 950-1. After forming a physical connection as discussed above, the conductive paths 140-2, 140-4, 140-6 become electrically connected via trace 950-2. Thus, the conductive path 140-1 and conductive path 140-3 are electrically isolated from each other except for or until electrical coupling between the conductive path 140-1 and the conductive path 140-3 provided by the trace 950-1 (e.g., route) in the substrate; the conductive path 140-2 and the conductive path 140-4 are electrically isolated from each other except for electrical coupling between the conductive path 140-2 and the conductive path 140-4 provided by the trace 950-2 (e.g., route) in the substrate; and so on.
(95) Via application of a gate signal to the circuits 210, the switch circuits 210 provide a low impedance path or high impedance path between trace 950-1 and trace 950-2. More specifically, an OFF gate signal causes the circuits 210 to provide a high impedance path. An ON gate signal causes the circuits to provide a low impedance path. Control signals for driving switch can be generated internally with respect to the electrical circuit 120 or received off-chip via signals on the host substrate that are passed up to the electrical circuit 120 via conductive paths in the leadframe device 190. In one embodiment, a driver circuit 410 disposed on electrical circuit 120 can be configured to generate the switch control signals based on receipt of an input signal. The input signal can be received by the driver circuit 410 from the circuit board substrate via one or more conductive path in the leadframe device 190 between the host substrate and the driver circuit.
(96)
(97) Step 1010 includes receiving an electrical circuit 120 such as an integrated circuit having multiple electrically isolated switch circuit nodes disposed thereon.
(98) Step 1020 includes receiving a leadframe device 190 in which to package the integrated circuit.
(99) Step 1030 includes electrically coupling the integrated circuit to a facing 150-1 of the leadframe device 190 to provide connectivity between the multiple electrically isolated switch circuit nodes of electrical circuit 120 via at least one conductive path 140 in the leadframe device 190.
(100)
(101) As shown, the electrical circuit 1120 can be configured to include multiple switch circuits that are completely independent with respect to each other. For example, instead of being driven by a gate signal produced on the electrical circuit 1120, each of circuits 1210-1, 1210-2, 1210-3, etc. can include a gate signal that is not tied to the gate signal of other circuits 1210. Thus, each switch circuit 1210 can be individually controlled. However, as shown in
(102)
(103) More specifically, a leadframe device 190 populated according to embodiments herein can be configured to include a phase controller 1240 (e.g., controller logic), a control driver 410 (e.g., control driver 410-1 and control driver 410-2), as well as any other conventional circuitry to control an output voltage applied to power load 118.
(104) In such an embodiment, phase controller 1240 monitors the output voltage 1280 and generates appropriate control signals for driving high side switch circuitry 1242 and low side switch circuitry 1246 in the leadframe device 190. The high side switch circuitry 1242 and low side switch circuitry 1246 of power supply system 1200 represent the functionality provided by connection of circuits 210 (on circuit 120) via conductive paths 140 to a host such as a printed circuit board as described herein.
(105) As previously discussed, additional conductive paths in the leadframe device 190 can provide connectivity between circuit 120 and a respective printed circuit board. Accordingly, any portion or functionality of a power supply system 1200 can reside in leadframe device 190 rather than on the printed circuit board. A benefit of such a configuration is space savings. Typically, conventional power supplies require layout of many components on a respective printed circuit board to create a power supply. This requires considerable printed circuit board real estate and cost to assemble. In contrast to conventional techniques, inclusion of control circuitry and/or related circuitry on leadframe device 190 as described herein can reduce an overall impact of populating a printed circuit board with a power supply control system because a printed circuit board can be populated with one or more leadframe devices rather than a multitude of individual components.
(106) Again, each of the high side switch circuitry 1242 and low side switch circuitry 1246 of leadframe device 190 can be configured in accordance with the techniques as discussed herein with respect to
(107) Each phase in power supply system 1200 can require a respective independently operating high side switch and low side switch. The leadframe device 190 can be configured to provide switching circuitry for each of a number of phases. Thus, in certain embodiments, the leadframe device 190 can include a multi-phase power supply controller and related circuitry.
(108) In addition to including control driver 410 as discussed above in
(109) Additionally, note that the leadframe device 190 can be configured to include a conductive path from circuit 120 to communication link 1291 on a printed circuit board such that the phase controller 1240 and processor 1292 (also on circuit board) can communicate with each other. In one embodiment, the output voltage 180 can be used to power the processor 1292.
(110) As shown in the example embodiment of
(111) As mentioned above, based on switching of the high side switch circuitry 1242 and the low side switch circuitry 1246, the leadframe device 190 (e.g., a power supply control system) can regulate the output voltage 1280 within a desired range for providing power to load 118.
(112) In one embodiment, leadframe device 190 can include respective circuitry to control any number of phases present in leadframe device 190 of a power supply system 1200. Each phase can include high side switch circuitry and low side switch circuitry as previously discussed. To deactivate a respective phase, the phase controller 1240 can set both high side switch circuitry 1242 and low side switch circuitry 1246 of the phase to an OFF state.
(113)
(114) As mentioned above, different families or sizes of leadframe devices can be manufactured using different numbers of circuits 210 (e.g., switch tiles 210). For example, a number circuits included in a leadframe device 190 can vary by adding or removing rows and/or columns of tiles of an integrated circuit that is subsequently packaged in a leadframe device. In accordance with a first specification, embodiments herein include: receiving a first integrated circuit, the first integrated circuit having a first set of electrically isolated switch circuit nodes disposed thereon; receiving a first leadframe device in which to package the first integrated circuit; and electrically coupling the first integrated circuit to a facing of the first leadframe device to provide connectivity between the first set of electrically isolated switch circuit nodes on the first integrated circuit via at least one conductive path in the first leadframe device.
(115) In accordance with a second specification that is modified or different with respect to the first specification, embodiments herein include: receiving a second integrated circuit, the second integrated circuit having a second set of electrically isolated switch circuit nodes disposed thereon, the second integrated circuit having a different number of electrically isolated switch circuit nodes than the first integrated circuit; receiving a second leadframe device in which to package the second integrated circuit; and electrically coupling the second integrated circuit to a facing of the second leadframe device to provide connectivity between the second set of electrically isolated switch circuit nodes via at least one conductive path in the second leadframe device. Thus, a number of switch tiles can be added or removed from design to design to create different families of devices.
(116)
(117) As shown, die 1400 (such as a semiconductor die) includes a first transistor 1242 and a second transistor 1246. A surface 1450 of the die 1400 (such as a flip-chip) includes multiple exposed conductive elements G1, S1, D1, G2, S2, and D2.
(118) The conductive elements on surface 1450 can be fabricated from any suitable conductive material. By way of a non-limiting example, the conductive elements are fabricated from solder and facilitate mounting of nodes on the surface 1450 of die 1400 to a respective host substrate such as a printed circuit board, lead frame device, electronic circuit package, etc.
(119) The conductive elements on the surface 1450 of die 1400 are electrically coupled to respective nodes of the first transistor 1242 and the second transistor 1246. For example, the exposed conductive element G1 of die 1400 is electrically connected to gate region 1421 of transistor 1242 disposed within die 1450; the exposed conductive element S1 of die 1400 is electrically connected to source region 1423 of transistor 1242 disposed within die 1400; the exposed conductive element D1 of die 1400 is electrically connected to drain region 1422 of transistor 1242 disposed within die 1450.
(120) The exposed conductive element G2 of die 1400 is electrically connected to gate region 1431 of transistor 1246 disposed within die 1450; the exposed conductive element S2 of die 1400 is electrically connected to source region 1433 of transistor 1246 disposed within die 1400; the exposed conductive element D1 of die 1400 is electrically connected to drain region 1422 of transistor 1242 disposed within die 1450.
(121) In one embodiment, each of the nodes (such as gate, source, drain nodes) of the transistors is electrically isolated from other nodes. As a non-limiting example, if desired, conductive element G1 can be connected only to gate region 1421 disposed within die 1400; conductive element D1 can be connected only to drain region 1422 disposed within die 1400; conductive element S1 can be connected only to source region 1423 disposed within die 1400; conductive element G2 can be connected only to gate region 1431 disposed within die 1400; conductive element D2 can be connected only to drain region 1432 disposed within die 1400; conductive element S2 can be connected only to source region 1433 disposed within die 1400.
(122)
(123) As shown, each of the conductive elements can be coupled to a respective transistor node via a respective conductive path disposed within the die 1400. For example, conductive element D1 of transistor 1242 can be electrically coupled to drain region 1422 (a doped region in die 1400) via a respective conductive path 1522 (fabricated from a material such as metal); conductive element G1 can be electrically coupled to gate region 1421 via a respective conductive path 1521 (fabricated from a material such as metal); conductive element S1 can be electrically coupled to source region 1423 (a doped region in die 1400) via a respective conductive path 1523 (fabricated from a material such as metal); and so on.
(124) In one embodiment, the conductive elements on surface 1450 of die 1400 can be sufficiently spaced apart from each other via one or more conductive paths extending longitudinally from a respective conductive element to a respective doped region. The conductive elements need not be dispose directly over a respective doped region. Transistor 1242 can be configured in a similar manner.
(125)
(126) As previously discussed, each of the conductive elements can be coupled to a respective transistor node via a respective conductive path disposed within the die 1400. In one embodiment, as shown, a respective conductive element can be disposed over a respective transistor region. For example, in one non-limiting embodiment, conductive element D1 can be substantially disposed over drain region 1422; conductive element G1 can be substantially disposed over gate region 1421; conductive element S1 can be substantially disposed over source region 1423; and so on. Transistor 1246 can be configured in a similar manner such that conductive element D2 is substantially disposed over a respective drain region of transistor 1246; conductive element G2 is substantially disposed over a respective gate region of transistor 1246; conductive element S1 is substantially disposed over a respective source region of transistor 1246; and so on.
(127)
(128) As shown, the surface 1450 of die 1400 can be flipped and mounted directly or indirectly on a respective exposed facing of host substrate 1600. In such an embodiment, the conductive elements of the die 1400 make direct contact with respective pads (such as metallic material) disposed on host substrate 1600.
(129) More specifically, when positioned properly, the conductive element S1 contacts pad 1620-5 on the exposed surface of host substrate 1600; the conductive element G1 contacts pad 1620-6 on the exposed surface of host substrate 1600; the conductive element D1 contacts pad 1620-1 on the exposed surface of host substrate 1600; the conductive element S2 contacts pad 1620-4 on the exposed surface of host substrate 1600; the conductive element G2 contacts pad 1620-3 on the exposed surface of host substrate 1600; the conductive element D2 contacts pad 1620-2 on the exposed surface of host substrate 1600.
(130) The pads 1620 disposed on exposed facing of host substrate 1600 are electrically connected to corresponding conductive elements of die 1400. For example, consistent with the power supply circuit in
(131) Thus, the surface 1450 of the die 1450 and corresponding conductive elements can be mounted directly on the host substrate 1600.
(132) Subsequent to fabrication, via control signals 1241-1 and 1241-2, the controller 1240 controls a state of switches 1242 and 1246 to produce output voltage 1280 within a desire range.
(133) As previously discussed, as an alternative to direct mounting, the surface 1450 of the die 1400 can be directly coupled to an electronic circuit package. The electronic circuit package provides connectivity between the respective nodes of die 1400 and the facing of the host substrate.
(134) Further as previously discussed, transistor 1242 in die 1400 can be electrically isolated from the transistor 1246 prior to mounting of the surface 1450 of the die 1400 to the facing of a respective host substrate 1600. At least one conductive path (such as conductive path 1610-2) disposed on the host substrate 1600 provides electrical connectivity between the transistor 1242 and transistor 1246.
(135) Note that, if desired, the die 1400 can include one or more conductive paths extending between respective transistors. For example, in one embodiment, the transistor 1242 (such as a control switch in a switching power supply) is electrically coupled to the transistor 1246 (such as a synchronous switch in a switching power supply) via a conductive path disposed in the die 1450.
(136) As shown in
(137)
(138) As shown, by way of a non-limiting example, to create a respective power supply circuit, drain D1 of die 1450 is electrically connected to the voltage source 1230. As previously discussed, controller 1240 drives gates G1 and G2. The source S1 and the drain D2 are electrically coupled to the inductor element 1244. Source S2 is connected to a ground node.
(139)
(140) As previously discussed, die 1400 can be used to fabricate a respective power supply circuit. However, note that a respective die is not limited to including just transistors. For example, the die 1800 as shown in
(141) In a similar manner as previously discussed, die 1800 can be flipped and mounted onto the respective host substrate 1600. Conductive paths (such as traces) on the host substrate 1600 provide connectivity between the conductive elements 1802 (e.g., conductive element 1802-1, conductive element 1802-2, conductive element 1802-3, conductive element 1802-4, etc.) and respective nodes in a power supply circuit including controller 1240. Accordingly, a respective die 1800 can include controller 1240.
(142) Nodes such as conductive elements 1802 associated with the controller 1240 fabricated in die 1800 can be electrically coupled to conductive paths on the host substrate. The conductive paths on the host substrate provide connectivity of the controller 1240 in die 1800 to respective nodes (e.g., conductive elements of the transistors, voltage sources, inductor elements, etc.) in the power supply circuit.
(143) Thus, die 1800 can be fabricated to include individual circuit components such as transistors, controllers, etc. Surface 1850 of the die 1800 can include conductive elements coupled to nodes of the respective components. Connectivity between elements in the die 1800 can occur when the die 1800 is flipped and mounted to the respective host substrate.
(144)
(145) In processing block 1910, the assembler receives a die such as die 1400. The die 1400 comprises: a first transistor 1242 and a second transistor 1246. A surface 1450 of the die 1450 includes multiple conductive elements (such as conductive element G1, S1, D1, G2, S2, . . . ) thereon. During the fabrication process, the multiple conductive elements on the surface 1450 are electrically coupled to respective nodes (e.g., gate region 1421, source region 1423, drain region 1422,) of the first transistor 1242 and the second transistor 1246.
(146) In processing block 1920, the assembler mounts a surface 1450 of the die 1400 to a facing of the host substrate 1600.
(147) Note again that techniques herein are well suited for use in packaging electronic parts such as those that provide switching capabilities. However, it should be noted that embodiments herein are not limited to use in such applications and that the techniques discussed herein are well suited for other applications as well.
(148) While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present application as defined by the appended claims. Such variations are intended to be covered by the scope of this present application. As such, the foregoing description of embodiments of the present application is not intended to be limiting. Rather, any limitations to the invention are presented in the following claims.