Probe card for a testing apparatus of electronic devices
11782075 · 2023-10-10
Assignee
Inventors
Cpc classification
International classification
Abstract
A probe card for a testing apparatus of electronic devices comprises a probe head housing a plurality of contact probes, each contact probe having at least one contact tip adapted to abut onto contact pads of a device under test, as well as a main support and an intermediate support connected to the main support and adapted to realize a spatial transformation of distances between contact pads on its opposite faces as a space transformer, the probe card suitably also comprising at least one connecting element adapted to link the space transformer and the main support, this connecting element having a substantially rod-like body and being equipped with a first end portion comprising at least one terminal section adapted to be engaged in a corresponding housing realized in the space transformer and with a second terminal portion adapted to abut onto an abutment element linked to the main support.
Claims
1. A probe card comprising: at least one probe head having a first side and a second side opposite to the first side, the at least one probe head housing a plurality of contact probes having respective first contact tips at the first side configured to abut onto contact pads of a device under test and having respective second contact tips at the second side; a main support and a space transformer connected to one another by a plurality of connecting elements, each connecting element having a rod-like body, a first end portion and a second end portion, the space transformer having a third side and a fourth side opposite to the third side, the main support being at the third side of the space transformer, wherein the space transformer includes a plurality of housings, each housing being configured to engage at least one terminal section of at least one connecting element of the plurality of connecting elements, and the main support includes a plurality of further housings, each further housing being configured to house without engagement the at least one connecting element of the plurality of connecting elements, and wherein the space transformer includes a plurality of multilayer modules, each being equipped with at least one connecting element of the plurality of connecting elements and being individually adjustable, respective multilayer modules of the plurality of multilayer modules being between the second side of the probe head and the fourth side of the space transformer, and the respective multilayer modules of the plurality of multilayer modules are coupled to corresponding ones of the respective second contact tips of the probe head.
2. The probe card of claim 1, further including an abutment element resting on the main support, wherein the abutment element includes a plurality of modular abutment elements, each being linked to one of the multilayer modules through at least one connecting element of the plurality of connecting elements.
3. The probe card of claim 2, wherein the second end portion of the at least one connecting element of the plurality of connecting elements has a maximum transverse dimension greater than a maximum transverse dimension of the body of the at least one connecting element and defining at least one undercut section configured to abut onto the abutment element.
4. The probe card of claim 2, wherein the abutment element is glued to the main support.
5. The probe card of claim 2, wherein the abutment element is formed of a material having a stiffness and a planarity greater than a material of which the main support is formed.
6. The probe card of claim 2, including connecting elements which are common to more than one of said multilayer modules and have a second end portion overlapping more that one of the abutment elements.
7. The probe card of claim 1, further including at least one frame equipped with a plurality of housing holes of the plurality of connecting elements and positioned between the main support and the space transformer.
8. The probe card of claim 7, further comprising at least one electrical connection interface positioned between the space transformer and the main support, in correspondence with the frame and configured to realize a link between corresponding pluralities of pads realized on the space transformer and on the main support, in correspondence with their sides facing one another in correspondence with the frame.
9. The probe card of claim 1, wherein the abutment element comprises a plurality of feet adjustable in a direction orthogonal to a plane defined by the abutment element being plate-like.
10. The probe card of claim 1, wherein the space transformer comprises at least one multilayer linked to a support the housing being realized at least partially in the multilayer.
11. The probe card of claim 1, wherein the space transformer comprises at least an MLO organic multilayer, linked to a ceramic support, the housing being realized at least partially in the multilayer.
12. The probe card of claim 1, wherein each respective multilayer module of plurality of multilayer modules includes a connecting element reception hole, and each of the respective first end portions of the plurality of connecting elements is inserted into a corresponding connecting element reception hole of the respective multilayer modules of the plurality of multilayer modules.
13. A probe card comprising: a plurality of contact probes, each of the contact probes having at least one contact tip configured to abut onto a contact pad of a device under test; at least one probe head housing the plurality of contact probes, the probe head having a first side and a second side opposite to the first side, the plurality of contact probes being at the first side, a main support; an intermediate support, the intermediate support including a third side and a fourth side opposite to the third side, the third side of the intermediate support being connected to the main support and configured to realize a spatial transformation of distances between contact pads on its opposite sides as a space transformer, the space transformer including a plurality of housings; a plurality of connecting elements configured to link the space transformer and the main support; and an abutment element linked to the main support, wherein each of the connecting elements has a substantially rod-like body, a first end portion and a second end portion, wherein the first end portion of each of the connecting elements includes at least one terminal section configured to be engaged in at least one housing of the plurality of housings of the space transformer, and the second end portion of each of the connecting elements is configured to abut onto the abutment element linked to the main support, and wherein the space transformer includes a plurality of multilayer modules at the fourth side of the intermediate support, respective multilayer modules of the plurality of multilayer modules are between the second side of the at least one probe head and the fourth side of the intermediate support, each respective multilayer module of the plurality of multilayer modules being equipped with at least one connecting element of the plurality of connecting elements and being individually adjustable.
14. The probe card of claim 13, wherein the abutment element includes a plurality of modular abutment elements, each being linked to one of the multilayer modules through at least one connecting element of the plurality of connecting elements.
15. The probe card of claim 14, including connecting elements which are common to more than one of said multilayer modules and have a second end portion overlapping more that one of the abutment elements.
16. The probe card of claim 13, wherein the terminal section of the first end portion of the at least one connecting element of the plurality of connecting elements is threaded and configured to engage with a housing in the form of threaded holes.
17. The probe card of claim 13, further including at least one frame equipped with a plurality of housing holes of the plurality of connecting elements and positioned between the main support and the space transformer.
18. The probe card of claim 17, further comprising at least one electrical connection interface positioned between the space transformer and the main support, in correspondence with the frame and configured to realize a link between corresponding pluralities of pads realized on the space transformer and on the main support, in correspondence with their sides facing one another in correspondence with the frame.
19. The probe card of claim 13, wherein the space transformer comprises at least an MLO organic multilayer, linked to a ceramic support, the housing being realized at least partially in the multilayer.
20. The probe card of claim 13, wherein each respective multilayer module of plurality of multilayer modules includes a connecting element reception hole, and each respective first end portion of the plurality of connecting elements is inserted into a corresponding connecting element reception hole of the respective multilayer modules of the plurality of multilayer modules.
21. A probe card comprising: at least one probe head housing a plurality of contact probes having respective contact tips configured to abut onto contact pads of a device under test; a main support and a space transformer connected to one another by a plurality of connecting elements, each connecting element having a rod-like body, a first end portion and a second end portion; and at least one frame equipped with a plurality of housing holes of the plurality of connecting elements and positioned between the main support and the space transformer, and wherein the space transformer includes a plurality of housings, each housing being configured to engage at least one terminal section of at least one connecting element of the plurality of connecting elements, and the main support includes a plurality of further housings, each further housing being configured to house without engagement the at least one connecting element of the plurality of connecting elements, wherein the space transformer includes a plurality of multilayer modules, each being equipped with at least one connecting element of the plurality of connecting elements and being individually adjustable, and wherein the first end portion of the at least one connecting element of the plurality of connecting elements has a maximum transverse dimension lesser than a maximum transverse dimension of the body and realizes at least one additional undercut section adapted to abut onto the frame.
22. A probe card comprising: a plurality of contact probes, each of the contact probes having at least one contact tip configured to abut onto a contact pad of a device under test; at least one probe head housing the plurality of contact probes, a main support; an intermediate support, the intermediate support being connected to the main support and configured to realize a spatial transformation of distances between contact pads on its opposite sides as a space transformer, the space transformer including a plurality of housings; a plurality of connecting elements configured to link the space transformer and the main support; an abutment element linked to the main support; and at least one frame equipped with a plurality of housing holes of the plurality of connecting elements and positioned between the main support and the space transformer, and wherein each of the connecting elements has a substantially rod-like body, a first end portion and a second end portion, wherein the first end portion of each of the connecting elements includes at least one terminal section configured to be engaged in at least one housing of the plurality of housings of the space transformer, and the second end portion of each of the connecting elements is configured to abut onto the abutment element linked to the main support, wherein the space transformer includes a plurality of multilayer modules, each being equipped with at least one connecting element of the plurality of connecting elements and being individually adjustable, and wherein the first end portion of each connecting element of the plurality of connecting elements has a maximum transverse dimension lesser than a maximum transverse dimension of the body and realizes at least one additional undercut section configured to abut onto the frame.
Description
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
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DETAILED DESCRIPTION
(7) With reference to said figures, and in particular to
(8) It is worth noticing that the figures represent schematic views and are not drawn to scale, but instead they are drawn so as to enhance the important features of the disclosure.
(9) Furthermore, the different aspects of the disclosure shown by way of examples in the figures can obviously be combined with each other and are interchangeable from one embodiment to another.
(10) In particular, as shown in
(11) Each of the contact probes 22 comprises in particular at least one first end or contact tip 22A adapted to abut onto a corresponding contact pad 23′ of a device under test 23, this contact pad being in particular comprised in a pad area AC of the device under test 23; in this way the desired contact, in particular an electric contact, between the contact probes 22 and the pads 23′ of the device under test 23, is established.
(12) Each contact probe 22 further comprises a second end or contact tip 22B adapted to abut, analogously to the contact tip 22A, onto a corresponding contact pad 24′ realized on an intermediate support, which is adapted to realize a spatial transformation and for this reason it is indicated as a space transformer 24. In particular, on a side F1 of the space transformer 24 a first pad area A1 having size and arrangement substantially analogous to the pad area AC of the device under test 23, is identified. In particular, the side F1 of the space transformer 24 faces the probe head 21, so that the pads 24′ of the first pad area A1 of the space transformer 24 can be contacted by the contact probes 22 of the probe head 21.
(13) By way of example, in the example shown in
(14) In fact, the aim of the spatial transformation realized by the space transformer 24, and in particular by its multilayer 25, is to be able to relax the distance constraints between pads in view of the connection with the testing apparatus (not shown).
(15) Furthermore, the support 26 comprises a third pad area A3 realized on a side F3 thereof, which is opposite the side resting on the second side F2 of the multilayer 25.
(16) Inside the support 26 suitable electric connections P1 are provided to achieve the routing between the plurality of pads 25′ of the second pad area A2 and the plurality of pads 26′ of the third pad area A3; in this way the connection is ensured between the plurality of pads 24′ of the first pad area A1 arranged on the side of the space transformer 24, in particular of its multilayer 25, facing the probe head, with the plurality of pads 26′ of the third pad area A3 arranged on the opposite side of the space transformer 24, in particular of its support 26, resting on a further support, in particular a main connection support with the testing apparatus, wholly indicated with 27 and also known in the field as main PCB since it is usually produced precisely through the printed circuit technologies or PCB technology. The main support 27 is in particular adapted to connect with the testing apparatus, in a manner known to the skilled person, comprising, to this end, a plurality of pads 27′ arranged on a side thereof, which is opposite the side resting on the space transformer 24, and suitably connected by means of further electric connections P2 to the plurality of pads 26′ of the third pad area A3 and thus to the plurality of pads of the first pad area A1 in contact with the contact probes 22 of the probe head 21.
(17) It is also pointed out that it is also possible to use a probe head of the micromechanical type as the so-called cantilever microprobes, with probes directly welded to the space transformer 24, the disclosure not being limited to a particular type of probe head as the vertical probe type illustrated in
(18) Advantageously according to the disclosure, the probe card 20 further comprises suitable connecting elements 30 able to link the different components of the card itself, and in particular the space transformer 24 and the main support 27, which are equipped, to this end, with corresponding housings, as well as an abutment element 28, made of a material having a stiffness and planarity greater than a material which the main support 27 is made of.
(19) More particularly, the abutment element 28 is realized by a support or metal plug. In fact, the normal metal working technologies allow producing supports or metal plugs having a high planarity, anyway in particular greater than the planarity that can be obtained through the PCB technologies through which the main support 27 is produced. Such metallic abutment element 28 is preferably made of a nickel-iron alloy, for instance a stainless steel, in particular having a high nickel content, or alloys known as 42, Nilo® 42, ivar 42 or NiFe 42 alloys, just to name a few.
(20) Suitably, as schematically illustrated in
(21) More particularly, the head portion 30B has a maximum transverse dimension, indicated as diameter D1 also for elements not having a circular section, which is greater than the diameter D2 of the body 30C, so as to define at least one undercut section Sq adapted to abut onto the abutment element 28. The head portion 30B also has a height H1 comprised between 0.5 mm and 3 mm, whereas the body 30C has a height H2 comprised between 10 mm and 30 mm.
(22) Furthermore, the tip portion 30A, having a height H3 comprised between 5 mm and 10 mm, comprises at least one terminal section 30A1 adapted to be engaged in a corresponding housing realized in the space transformer 24, for instance in its multilayer 25. Such terminal section 30A1 in particular has a height H4 comprised between 3 mm and 7 mm, preferably lesser than a thickness of the multilayer 25.
(23) It is also possible to realize connecting elements 30 having tip portions 30A only partially extending in the multilayer 25, the terminal section 30A1 engaging in the space transformer 24 being able in this case to be realized also at least partially in correspondence with the support 26, which is in turn equipped with suitable housings for this terminal section 30A1.
(24) In a preferred embodiment, the terminal section 30A1 is suitably threaded and is adapted to be engaged, in particular by screwing, in housings in the form of threaded holes realized in the space transformer 24 and possibly in further housings in the form of at least partially threaded holes realized in the support 26.
(25) The clamping obtained thanks to the engagement of the connecting elements 30 of the terminal section 30A1 of their tip portion 30A in the space transformer 24, in particular in its multilayer 25 and the abutment of their head portion 30B, in particular with their undercut section Sq, onto the abutment element 28 ensures the correct link of the main support 27 with the space transformer 24, thus improving the planarity of the probe card 20 in its whole and making it sufficiently stiff to ensure a correct contact of the contact probes during the testing of electronic devices.
(26) In order to improve a correct positioning, it is also possible to glue the abutment element 28 on the main support 27, though it is pointed out that its retainment is already performed by the connecting elements 30 and in particular by the undercut sections Sq of their head portions 30B.
(27) It is also pointed out that the realization of the housings in the space transformer 24 allows ensuring high levels of precision and therefore of positioning of the connecting elements 30, in particular of their tip portions 30A, which are equipped with terminal sections 30A1, adapted to be housed and in particular to be engaged in correspondence with these housings, the space transformer 24 being a component of the probe card 20 achievable through a technology having greater precision than the technology producing the main support 27, in particular a fine pitch technology, and therefore ensuring a precise positioning of the housings therein realized and thus of the connecting elements 30 therein engaged. The positioning precision of the housings and therefore of the connecting elements 30 is further improved in case the space transformer 24 comprises the multilayer 25 wherein these housings are realized.
(28) It is also possible to equip the space transformer 24 with suitable align elements, which help realizing the housings in precisely determined positions.
(29) It is also pointed out that further housings, realized in the main support 27 and possibly in the support 26, adapted to house the connecting elements 30 without engagement, in particular the non-threaded holes, on the contrary do not need a particular precision, the correct working of these connecting elements 30 being ensured by the abutment of their head portions 30B onto the abutment element 28.
(30) Substantially, the use of the connecting elements 30 having at least one terminal section adapted to be engaged in housings, for instance in the form of threaded holes, realized in a high-precision portion of the probe card 20, in particular the space transformer 24 and more particularly its multilayer 25, ensures a correct positioning of the space transformer 24 with respect to the probe head 21 in a plane XY defined by the main support 27 (indicated in section in
(31) In a preferred embodiment, the probe card 20 further comprises at least one frame 29 suitably equipped with a plurality of housing holes for the connecting elements 30 and arranged between the main support 27 and the space transformer 24, in particular its support 26. Such frame 29 suitably perforated actually realizes a reference in the plane XY for the positioning of these connecting elements 30.
(32) In this case, the main support 27 comprises in turn a fourth pad area A4 realized on its side F4 facing the frame 29 and including a plurality of pads 27′ in connection with the plurality of pads 26′ of the third pad area A3 by a suitable electric connection interface 29A arranged between the main support 27 and the space transformer 24. More particularly, the electric connection interface 29A realizes a point-to-point connection between the plurality of pads 27′ of the fourth pad area A4 and the plurality of pads 26′ of the third pad area A3.
(33) By way of example, it is possible to realize this electric connection interface 29A by means of a plurality of conductive pegs or sponges or by means of a plurality of microprobes, for instance of the pogo pin type, able to connect corresponding pairs of pads comprised in the third and fourth pad areas A3 and A4, respectively.
(34) Furthermore, according to this preferred embodiment, the tip portion 30A of the connecting elements 30 is realized with a diameter D3 lesser than the diameter D2 of the body 30C, thus realizing further undercut sections Sq′ in correspondence with the frame 29.
(35) This preferred embodiment of the probe card 20 according to the present disclosure further improves the positioning precision of the space transformer 24 in the plane XY, in particular thanks to the combination of the housings, for instance threaded holes therein realized, and of the housing holes realized in the frame 29 for housing the connecting elements 30. In particular, this frame 29 is preferably realized by means of a metal sheet, which allows a high precision in making the housing holes for the connecting elements 30 therein realized. Furthermore, the presence of the further undercut sections Sq′ of the body 30C in correspondence with the frame 29 improve the clamping of the components of the probe card 20 and ensure a correct positioning according to the direction Z of the space transformer 24 retained by these connecting elements 30.
(36) It is furthermore possible to equip the abutment element 28 with suitable adjustable feet 31, in particular in the direction Z, orthogonal to a plane defined by the abutment element 28, realized in correspondence with the connecting elements 30.
(37) Thanks to this adjustable feet 31, it is in particular possible to move in the direction Z the entire probe card 20, which is already made integral by the connecting elements 30 and thus as a single block, with respect to probe head 21.
(38) The probe head 20 comprises in particular at least two connecting elements 30, as illustrated in
(39) It is possible to arrange these connecting elements 30 in correspondence with vertices of the space transformer 24, in particular of its multilayer 25, preferably of square or rectangular shape, possibly with rounded edges, as illustrated for instance in
(40) It is also possible to arrange these connecting elements 30 in correspondence with the sides of the space transformer 24, in particular of its multilayer 25, preferably of square or rectangular shape, for instance in a substantially central position of these sides, as illustrated for instance in
(41) In a preferred embodiment, the probe card 20 comprises four connecting elements 30 positioned in correspondence with the vertices of the space transformer 24, in particular of its multilayer 25, as schematically illustrated in
(42) Anyway the possibility is evident to use any number of connecting elements 30 positioned in any way on the space transformer 24 and in particular on its multilayer 25, obviously in a manner so as not to interfere with the positioning of the plurality of pads of the first pad area A1 and also of the corresponding second, third and fourth pad areas, A2, A3 and A4 defined on space transformer 24 and main support 27, these connecting elements 30 passing through and being housed in holes realized in the space transformer 24, in particular in its multilayer 25 and in its support 26, but also in the main support 27.
(43) Thanks to the positioning precision obtained through the connecting elements 30, it is also possible to realize the space transformer 24 by means of a plurality of modular elements, each equipped with corresponding connecting elements 30 for the positioning in XYZ.
(44) More particularly, as schematically illustrated in
(45) As previously, each connecting element 30 has a tip portion 30A equipped with a terminal section adapted to be engaged in housings realized in a corresponding multilayer module 25.sub.1 . . . 25.sub.N and with a head portion 30B abutting onto an abutment element, for instance a common abutment element 28 linked to the main support 27, as explained in connection with
(46) It is pointed out that, according to this embodiment, it is possible to obtain a highly precise positioning of the space transformer 24, each multilayer module 25.sub.1 . . . 25.sub.N being individually adjustable. In this way it is possible to realize space transformers with an even high surface area.
(47) Preferably, as schematically illustrated in
(48) In particular, the connecting elements 30 may be suitably realized in correspondence with vertices of the modular abutment elements 28.sub.1 . . . 28.sub.N, the head portions 30B being preferably realized with sizes, in particular with a diameter D1 adapted to overlap more than one modular abutment element 28.sub.1 . . . 28.sub.N. Analogously, it is possible to realize these connecting elements 30 in correspondence with sides of modular abutment elements 28.sub.1 . . . 28.sub.N, which are side by side to each other, the head portions 30B overlapping anyway more than one modular abutment element 28.sub.1 . . . 28.sub.N.
(49) The connecting elements 30 so realized are therefore able to link at least one pair of modular abutment elements 28.sub.1 . . . 28.sub.N to the main support 27, thanks to their head portions 30B overlapped to this pair of modular abutment elements 28.sub.1 . . . 28.sub.N.
(50) In this way it is possible to reduce the number of connecting elements 30 used, some of them being common with more than one of the multilayer modules 25.sub.1 . . . 25.sub.N and more than one of the modular abutment elements 28.sub.1 . . . 28.sub.N.
(51) It is also possible to realize these multilayer modules 25.sub.1 . . . 25.sub.N by overlapping, in particular gluing, one multilayer portion, such as for instance an MLO, and one support portion, for instance of the ceramic type, all of the support portions of the single multilayer modules 25.sub.1 . . . 25.sub.N being thus linked to the common support 26.
(52) In this case as well, the connecting elements 30 are equipped with tip portions 30A having at least one terminal section 30A1 adapted to be engaged in a corresponding housing and which can extend along the entire thickness of the multilayer modules 25.sub.1 . . . 25.sub.N or of their multilayer portion or even in their support portion and only partially in the multilayer portion.
(53) In conclusion, advantageously according to the disclosure, a high-planarity probe is obtained thanks to the presence of the connecting elements and of the abutment element adapted to link the components of the probe card itself, in particular the main support and the space transformer.
(54) In particular, these connecting elements allow a correct positioning of the space transformer in XYZ and thus ensure the correct contact thereon, in particular on the plurality of pads realized thereon, of the contact probes of the probe head comprised in the probe card during the testing of electronic devices integrated on wafers.
(55) Suitably, the probe card may also be equipped with a frame able to realize a reference for a more precise positioning of the connecting elements and therefore of the space transformer, in particular in XY. Such connecting elements can furthermore be realized so as to define undercut sections able to abut onto the frame and thus to ensure a more precise positioning thereof in Z and thus of the space transformer.
(56) Furthermore, the probe card according to the disclosure has the possibility to further locally adjust the planarity of the space transformer realized by means of a plurality of multilayer modules that are individually adjustable.
(57) This adjustment possibility allows further releasing the constraints linked to the manufacture of the space transformer.
(58) Finally, it is pointed out that the probe card is also suitable for applications in which it is necessary to test large wafers and devices with a high number of pads.
(59) From the foregoing it will be appreciated that, although specific embodiments of the disclosure have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the disclosure.
(60) The various embodiments described above can be combined to provide further embodiments. These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.