Bonding interposer and integrated circuit chip, and ultrasound probe using the same
11631798 · 2023-04-18
Assignee
Inventors
Cpc classification
H01L2224/816
ELECTRICITY
H01L2224/16112
ELECTRICITY
H01L2924/00014
ELECTRICITY
A61B8/4461
HUMAN NECESSITIES
H01L2224/81007
ELECTRICITY
H01L2224/81855
ELECTRICITY
H01L2224/81191
ELECTRICITY
H10N30/03
ELECTRICITY
H01L2924/00014
ELECTRICITY
A61B2562/12
HUMAN NECESSITIES
H01L21/486
ELECTRICITY
H01L2224/816
ELECTRICITY
H10N30/20
ELECTRICITY
H01L2224/16235
ELECTRICITY
H01L2224/8159
ELECTRICITY
H01L25/16
ELECTRICITY
G01S15/8925
PHYSICS
H10N30/875
ELECTRICITY
H01L2224/8159
ELECTRICITY
G01S7/5208
PHYSICS
H01L2224/16237
ELECTRICITY
International classification
A61B8/00
HUMAN NECESSITIES
B06B1/06
PERFORMING OPERATIONS; TRANSPORTING
H01L21/48
ELECTRICITY
H01L23/538
ELECTRICITY
Abstract
The method of bonding an interposer and an integrated circuit chip includes preparing an interposer including an insulator and conductive lines each having one end exposed to a first surface of the insulator and another end exposed to a second surface opposite to the first surface; placing a bonding mask on the interposer; forming through-holes on the bonding mask before or after the placing of the bonding mask on the interposer; filling the plurality with a conductive material; and bonding an integrated circuit chip to the bonding mask.
Claims
1. A method comprising: preparing an interposer, the preparing comprising: forming a plurality of first conductive lines in an insulator, wherein first ends of the plurality of first conductive lines are exposed through the insulator to a first surface of the insulator and second ends of the plurality of first conductive lines are exposed through the insulator to a second surface of the insulator that is opposite to the first surface of the insulator; forming a plurality of second conductive lines in the insulator, wherein first ends of the plurality of second conductive lines are exposed through the insulator to a side surface of the insulator, the side surface extending from the first surface of the insulator to the second surface of the insulator, and wherein second ends of the plurality of second conductive lines are exposed through the insulator to the second surface of the insulator; placing a bonding mask on the second surface of the insulator; forming through-holes on the bonding mask; filling the through-holes with a conductive material; and bonding an integrated circuit chip to the bonding mask, wherein the forming the through-holes further comprises: after the placing the bonding mask on the insulator, forming the through-holes on the bonding mask by laser emission, and wherein the bonding mask includes a transparent film.
2. The method of claim 1, wherein the bonding the integrated circuit chip to the bonding mask comprises flip-chip-bonding the integrated circuit chip to the bonding mask.
3. The method of claim 2, wherein the bonding the integrated circuit chip to the bonding mask further comprises: placing bump balls on electrode terminals of the integrated circuit chip; and inserting the bump balls into the through-holes while the integrated circuit chip is aligned with the bonding mask.
4. The method of claim 1, wherein the conductive material comprises conductive epoxy.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The above and other aspects, features, and advantages of certain embodiments of the present disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
(2)
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DETAILED DESCRIPTION
(13) Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects.
(14) The present disclosure does not describe all elements of embodiments, and a general description in a technical field to which the present disclosure belongs or a repetitive description in the embodiments will be omitted. As used herein, the term “module” or “unit” may be embodied in one or more combinations of software, hardware, and firmware. Depending on embodiments, a plurality of “modules” or “units” may be implemented as a single element, or a single “module” or “unit” may include a plurality of elements.
(15) The term “object” as used herein refers to be a target to be photographed and may include person, animal, or part thereof. For example, the object may include a human part (e.g., an organ), a phantom, or the like.
(16) Through the specification, the term “ultrasound image” refers to an image of an object that is processed on the basis of ultrasound signals transmitted to and reflected by the object.
(17)
(18) Referring to
(19) A lower electrode layer 160 is provided under the piezoelectric layer 170. The lower electrode layer 160 may be formed of a material with high conductivity and high acoustic impedance. For example, the lower electrode layer 160 may be formed of a material such as tungsten or a tungsten carbide. The lower electrode layer 160 has a plurality of lower electrodes separated apart from one another to correspond to, and prevent electrical interconnection between, the piezoelectric elements 171 of the piezoelectric layer 170.
(20) An acoustic matching layer 180 is provided on the piezoelectric layer 170.
(21) A common electrode layer may be provided between the piezoelectric layer 170 and the acoustic matching layer 180. When the acoustic matching layer 180 is formed of a conductive material, the acoustic matching layer 180 itself may function as a common electrode layer.
(22) An acoustic lens layer 190 may be provided on the acoustic matching layer 180. The acoustic lens layer 190 may be omitted.
(23) The piezoelectric layer 170, the acoustic matching layer 180, and the acoustic lens layer 190, which have been described above, constitute a 2D acoustic module 98.
(24) An electrical interconnection assembly for electrical wiring of each of the piezoelectric elements 171 of the piezoelectric layer 170 is provided under the 2D acoustic module.
(25) The electrical interconnection assembly includes an integrated circuit chip 140 that is electrically connected to the 2D acoustic module via the interposer 110 and a bonding mask 130. As described above, the piezoelectric layer 170 may have thousands of piezoelectric elements 171 in which signals are transmitted or received independently. Since a cable for electrically connecting the ultrasound probe to a main body of an ultrasound diagnostic apparatus has a limitation on the number of wirings, it is not easy to include all wirings corresponding to the piezoelectric elements 171 on a one-to-one basis in the cable. The integrated circuit chip 140 may be an application specific integrated circuit (ASIC) including a circuit for reducing the number of wires needed for communication between the ultrasound diagnostic apparatus and any external source in the ultrasound diagnostic apparatus. The integrated circuit chip 140 may have a surface-mounted package, such as a ball grid array (BGA), where electrode terminals are arranged on a flat plate surface. The integrated circuit chip 140 includes first terminals 533 provided on the flat plate surface. Here, first terminals correspond to the piezoelectric elements 171 of the piezoelectric layer 170 on a one-to-one basis, and Tx/Rx signals are transferred to the first terminals. The integrated circuit chip 140 includes second terminals 535 for transmitting and receiving electrical signals to and from an external source to supply power to, and control, the integrated circuit chip 140. Second terminals may also be formed on the flat plate surface on which the first terminals are formed and on outer sides of the first terminals.
(26) An interposer 110 is provided between the 2D acoustic module and the integrated circuit chip 140. The interposer 110 will be described in detail when a manufacturing method is described later.
(27) One or more electrode pads 1155 (refer to
(28) A flexible printed circuit board 150 for external wirings may be attached to the side surface of the interposer 110. For example, an electrode pad 155 of the flexible printed circuit board 150 may be brought into contact with conductive wires of an outwardly extending cable. The conductive wires of the cable may be connected to the electrode pad 1155 located on the side surface of the interposer 110, without the flexible printed circuit board 150.
(29)
(30) Referring to
(31)
(32) Because the piezoelectric layer 170 is located on the first side portion 1111a of the insulator 1111, the curved shape of the first side portion 1111a defines a curved shape of the piezoelectric layer 170 and also defines a curved surface of the ultrasound probe 100 that is in contact with an object 610 (refer to
(33) Guide holes 1112 and 1113, which serve as a first guide portion when a plurality of circuit boards being stacked, may be provided on the circuit board 1110. The number or positions of the guide holes 1112 and 1113 may be set such that the first conductive lines 1115 are not obstructed and do not limit embodiments of the present disclosure. The guide holes 1112 and 1113, which are examples of a means for performing guidance when the circuit boards 1110 are stacked, may be modified in various shapes. For example, a groove, instead of a hole, may be formed at one side portion of the circuit board 1110 such that such a groove serves as a guide when the circuit boards 1110 are stacked.
(34) Referring to
(35) Referring to
(36) Referring to
(37) Second conductive lines 1156 are located inside the outer substrate 1150. First ends 1160 of the second conductive lines 1156 are exposed to an outer flat plate surface of the outer substrate 1150, and the second ends 1162 of the second conductive lines 1156 are exposed to the second side portion 1151b.
(38) The second side portion 1151b of the outer substrate 1150 is in contact with the integrated circuit chip 140 via the bonding mask 130 being interposed therebetween. Thus, the second ends of the second conductive lines 1156 are electrically connected to the second terminals of the integrated circuit chip 140.
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(40) In an embodiment, the interposer 110 has an upper surface 110a to which the first ends of the first conductive lines 1115 are exposed and a lower surface 110b to which the second ends of the first and second conductive lines 1115 and 1156 are exposed. In this case, the first ends of the first conductive lines 1115 are to be electrically connected to the piezoelectric elements 171, and the second ends of the first conductive lines 1115 are to be electrically connected to the first terminals of the integrated circuit chip 140. The second ends of the second conductive lines 1156 located at the outer side are to be electrically connected to the second terminals of the integrated circuit chip 140. The first ends of the second conductive lines 1156 are exposed to a side surface of the interposer 110 to form electrode pads 1155 so as to enable electrical interconnection to the outside.
(41)
(42) Referring to
(43) Subsequently, as shown in
(44) Subsequently, as shown in
(45) There may be thousands of piezoelectric elements 171. The piezoelectric elements 171 may be separated into four groups, and four integrated circuit chips 141, 142, 143, and 144 may provide inputs and/or outputs for four groups. It will be appreciated that the number of groups or the circuit chips does not limit an embodiment. In some cases, a single integrated circuit chip 140 may be used to provide inputs and/or outputs of all of the piezoelectric elements 171.
(46) Subsequently, as shown in
(47) Referring to
(48) In the foregoing embodiments, the interposer 110 has been described as an example in which electrode pads 1155 are formed on both sides of the interposer 110. However, it will be appreciated that the outer substrate 1150 may be provided on only one side of the interposer 110 and the electrode pad 1155 may be formed on only one side.
(49)
(50) Referring to
(51) Subsequently, as shown in
(52) Subsequently, referring to
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(55) Subsequently, referring to
(56) Subsequently, referring to
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(58) Referring to
(59) Because the first side portion 1111a has a flat plate shape, the piezoelectric layer 170 also has a flat plate shape.
(60) Referring to
(61) Referring to
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(64) Referring to
(65) Subsequently, as shown in
(66) Next, as shown in
(67) Referring back to
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(70) Alternatively, the second terminals 535 for transmitting and receiving electrical signals to and from the outside in order to power on, and control, the integrated circuit chip 140 may be exposed and connected to a flexible printed circuit board through wire bonding.
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(72) The ultrasound probe 100 may be a 2D probe that is manufactured by the aforementioned embodiments. Also, the ultrasound transceiver 630 may include an analog beamformer 633 and a digital beamformer 635. The ultrasound transceiver 630 and the ultrasound probe 100 are shown as being separate components in
(73) The controller 640 may calculate a time delay value for digital beamforming for each of a plurality of sub-arrays included in a 2D transducer array. Also, the controller 640 may calculate a time delay value for analog beamforming for each transducer included in any one of the plurality of sub-arrays. The controller 640 may control the analog beamformer 633 and the digital beamformer 635 to form transmission signals to be applied to each of a plurality of transducers according to the time delay value for analog beamforming and the time delay value for digital beamforming. The controller 640 may control the analog beamformer 633 to add signals received from the plurality of transducers on a sub-array basis according to the time delay value for analog beamforming. Also, the controller 640 may control the ultrasound transceiver 630 to perform analog-to-digital conversion on the signals added on a sub-array basis. Also, the controller 640 may control the digital beamformer 635 to add digitally converted signals according to the time delay value for digital beamforming to generate ultrasound data. The ultrasound probe 100 according to an embodiment may include some or all elements of the controller 640.
(74) The image processor 650 may generate an ultrasound image using the generated ultrasound data.
(75) The display 660 may display the generated ultrasound image and a variety of information processed by the ultrasound diagnostic apparatus 600. The ultrasound diagnostic apparatus 600 may include one or a plurality of displays 660. Also, the display 660 may be combined with a touch panel and implemented as a touch screen and may provide an input and/or an output functionality.
(76) The controller 640 may control an overall operation of the ultrasound diagnostic apparatus 600 and also control a signal flow between the components of the ultrasound diagnostic apparatus 600. The controller 640 may include a processor configured to process data or programs for performing functions of the ultrasound diagnostic apparatus 600. Also, the controller 640 may receive a control signal from the input unit 690 or an external apparatus to control operation of the ultrasound diagnostic apparatus 600.
(77) The ultrasound diagnostic apparatus 600 may include the communicator 680 and may be connected to an external apparatus such as a server, a medical device, or a portable device (e.g., a smartphone, a tablet computer, a wearable device, or the like) through the communicator 680.
(78) The communicator 680 may include one or more elements capable of communicating with an external apparatus. For example, the communicator 680 may include at least one of a short-range communication module, a wired communication module, and a wireless communication module.
(79) The communicator 680 may transmit and receive data and control signals to and from an external apparatus.
(80) The storage 670 may store ultrasound images, ultrasound data that is input or to be output, and various programs or data for driving and controlling the ultrasound diagnostic apparatus 600.
(81) The input unit 690 may receive a user input for controlling the ultrasound diagnostic apparatus 600. For example, the user input may include, but is not limited to, an input for manipulating a button, a keypad, a mouse, a trackball, a jog switch, a knob, etc., an input for touching a touch pad or a touch screen, a voice input, a motion input, a biometric information input (e.g., iris recognition, fingerprint recognition, etc.), and the like.
(82) By using the interposer according to the embodiments, it is possible for the ultrasound probe according to the embodiments to connect the transducer elements in the central region in addition to the transducer elements in the peripheral region.
(83) In the method of manufacturing an interposer according to the embodiments, by stacking printed circuit boards (PCBs), e.g., the circuit boards 1110, to manufacture an interposer and also facilitating connection with peripheries such as an integrated circuit chip, a connector, a cable, and the like, it is possible to accomplish cost reduction, process unification and simplification, and structure simplification.
(84) The method of bonding an interposer and an integrated circuit chip and an ultrasound probe using the method according to the present disclosure have been described with reference to the embodiments shown in the drawings for only illustrative purposes in order to facilitate an understanding thereof. Therefore, it will be understood by those skilled in the art that various changes and equivalents thereof may be made. Accordingly, the technical scope of the present disclosure should be determined only by the appended claims.