Test device probe card for electronic devices with improved thermal management

Abstract

There is described a probe card (10) configured to be mounted in a test apparatus of electronic devices and to be in contact with a test unit (17) of said test apparatus, the probe card (10) comprising at least one probe head (11) housing a plurality of contact probes (1) and arranged between a device to be tested (13) and a spatial converter (14), the spatial converter (14) in turn being in contact with a main board (15), the main board (15) is configured to be connected with the test unit (17) and is provided with a reinforcing member (16). Suitably, the probe card (10) comprises a heat dissipation device (20) provided with at least one heat pipe (19) for thermally connecting the probe card (10) and the test unit (17) and enabling the dissipation of heat generated by the probe card (10) during operation.

Description

Technical Field

[0001] The present invention relates to a probe card for a test device of electronic devices integrated on a semiconductor wafer. The following will be described for this application field only for the purpose of simplifying the exposition. Background Art

[0002] As is well known, a probe card is essentially a device for electrically connecting a plurality of contact pads of a micro-structure (especially an electronic device integrated on a wafer) to corresponding channels of a test device that performs its tests.

[0003] The tests performed on integrated devices are used to detect and isolate defective devices at an early stage of the production phase. Usually, a probe card is used to perform electrical tests on integrated devices on a wafer or a chip, and then the wafer or chip is diced or singulated and assembled into a package.

[0004] The probe card includes a probe head, which basically includes a plurality of movable contact elements or contact probes, each of which has at least one end or contact tip adapted to abut against a contact pad among a plurality of corresponding contact pads of the device under test. Here, the end or tip refers to the end of the probe, but it is not necessarily sharp.

[0005] As is well known, the effectiveness and reliability of measurement tests depend, among other factors, on establishing a good electrical connection between the device under test and the test device, thereby establishing an optimal probe head / pad electrical contact.

[0006] Among various types of probe heads used in this technical field for testing integrated devices on wafers, the so-called vertical probe heads are very common, in which the contact probe heads are substantially perpendicular to the plane where the device under test is located.

[0007] In particular, the vertical probe head includes fixing a plurality of contact probe heads by at least one plate or guide (usually by a pair of plates or guides), and these plates or guides are substantially plate-shaped and parallel to each other. These guides are kept at a certain distance from each other to leave a free space or air gap for the movement and possible deformation of the contact probe heads during the test, and they are provided with appropriate guide holes adapted to slidably accommodate the contact probe heads.

[0008] More specifically, this pair of guides includes an upper guide (upper mold) and a lower guide (lower mold), both of which are provided with guide holes through which the contact probes can slide axially. The contact probes are usually made of a special alloy wire with good electrical and mechanical properties (also known as "needles" in this field). The term "lower" usually refers to the guide closer to the device under test.

[0009] A good connection between the contact probes of the probe head and the contact pads of the device under test is achieved by pressing the probe head against the device under test. The contact probes can move within the guiding holes of the upper and lower guiding members. During the pressing contact process, the probes bend within the air gap between the two guiding members and slide within the accommodating guiding holes.

[0010] The bending of the contact probes within the air gap can also be assisted and guided by appropriate configurations of the probes themselves or the guiding members, especially by using pre-deformed contact probes or appropriately laterally moving the guiding members including the probes. The lateral direction refers to the direction substantially parallel to the plane of the device under test and the guiding members.

[0011] Generally, probe heads are used where the probes are not fixedly fastened but are in docking with an appropriate main board, and then the main board is connected to the test equipment: In this case, these probe heads are called unblocked probe heads. The main board is also called the main PCB because it is usually made using printed circuit or PCB ("printed circuit board") technology, which allows the formation of a circuit board with active areas (including contact pads), and can even be of large size. However, the PCB technology has great limitations in terms of the minimum achievable value of the distance (pitch) between the centers of the contact pads on the probe card. Therefore, the PCB technology is usually only used to form the main board because the pitch constraint between the pads on the main board is less strict than that of the device under test.

[0012] Due to the use of an intermediate board or a space converter, the distance between the contact pads (especially the pitch between adjacent contact pads on the main board) can have a looser constraint. Contact pads are provided on opposite faces of the space converter, and the pitch between the centers of the contact pads on the two faces is different. These contact pads are appropriately interconnected through connections (especially metal lines) inside the space converter.

[0013] In this case, the contact probe head has another end or contact head, which is adapted to rest against a plurality of contact pads on the first face of the space converter (especially the face facing the probe head and the corresponding device under test).

[0014] The contact between the probe and the device under test is similar. By pressing the probe (especially the contact head of the probe) against the contact pads of the space converter, a good electrical contact between the contact probe and the space converter can be ensured.

[0015] In addition, the main board is generally fixed in place by a reinforcing member.

[0016] The combination of the probe head, the main board, the intermediate board or the space converter, and the reinforcing member constitutes a probe card.

[0017] In vertical probe head technology, it is particularly important to ensure good connections of the contact probes at their contact tips with the device under test, at their contact tips with the test apparatus, and thus with the space converter. This is especially important when testing integrated circuits manufactured according to the latest integration technologies, as these technologies provide contact pads on the device under test with extremely close pitch and very small dimensions. However, as mentioned above, these constraints are not compatible with the PCB technology for forming the probe card main board.

[0018] The mutual positioning of the various elements that make up the probe card is also an extremely important parameter for the correct operation of the probe card itself. Different technologies used to manufacture these elements can cause flatness problems, complicating the overall configuration of the probe card, especially in terms of the mutual positioning of the intermediate board or space converter and the main board. Unfortunately, even with reinforcements that make the entire assembly more robust and durable, it is not possible to fully eliminate the flatness defects of the space converter or ensure its correct and complete contact with the main board.

[0019] Especially when performing test operations at extreme temperatures, the operating temperature of the probe card itself makes the whole problem more complex. In fact, in such cases, due to the different coefficients of thermal expansion of the different materials of the different elements that make up the probe card, the thermal expansion of these elements that make up the probe card affects its correct performance. In fact, the elements that make up the probe card are usually fixed together by screws. Especially during temperature tests, the screws exert constraints on the different boards, causing them to bend, which in turn can lead to failures of the entire probe card and even prevent the contact probes of the probe head from contacting the contact pads of the device under test. In addition, during the test operation, the contact probes heat up due to the transmission of several signals, thus increasing the heat present inside the probe head, especially when the probe head has a large number of contact probes.

[0020] Similarly, when the contact probes rest on the pads of the space converter and transmit signals therein, unnecessary heat accumulates in the probe card.

[0021] This problem is particularly prominent in large probe cards, such as probe cards used to test memory devices (such as DRAM) or probe cards used for multi-chip testing. For such probe cards, serious problems can be triggered during the test phase if the thermal expansion of the elements cannot be controlled.

[0022] The technical problem of the present invention is to provide a probe card whose structural and functional characteristics can overcome the limitations and drawbacks still existing in probe cards manufactured using known technologies, which is conducive to eliminating the heat generated during the test operation, restricting the rise in the operating temperature of the probe card and the probe head contained therein, while improving the thermal management of the probe card and controlling the thermal expansion experienced by the elements that make up the probe card. Summary of the Invention

[0023] The solution idea of the present invention is to provide a heat dissipation device for the probe card, which is composed of appropriate elements for heat exchange and is generally called a heat pipe.

[0024] According to this solution idea, the technical problem is solved by a probe card configured to be installed in a test device of an electronic device and in contact with a test unit of the device. The probe card includes at least one probe head that houses a plurality of contact probes and is arranged between the device under test and a space converter, and the space converter is in contact with a main board that is configured to be connected to the test unit and is provided with a reinforcement. Appropriately, the probe card includes a heat dissipation device provided with at least one heat pipe for thermally connecting the probe card and the test unit and realizing the dissipation of heat generated inside the probe card during operation.

[0025] More specifically, the present invention includes the following additional and optional features, which can be used alone or in combination as needed.

[0026] According to one aspect of the present invention, at least one heat pipe can be of a passive type and made of a material with a thermal conductivity greater than 100 W / (m·K), preferably greater than 500 W / (m·K).

[0027] More specifically, at least one heat pipe can be made of a material selected from copper, aluminum, aluminum nitride, silicon nitride, silicon carbide, and CVD-D (chemical vapor deposition - diamond) materials.

[0028] According to another aspect of the present invention, at least one heat pipe can include a first end in thermal contact with the test unit, preferably abutting against the test unit; at least one heat pipe can also include a second end in thermal contact with the main board, preferably abutting against the main board.

[0029] More specifically, the first end of at least one heat pipe can be arranged at a part where the first surface of the reinforcement is in contact with the test unit; in addition, the second end of at least one heat pipe can be arranged at a part where the second surface of the reinforcement is in contact with the main board.

[0030] According to another aspect of the present invention, the second end of at least one heat pipe can be connected to the first surface of the main board by one of the following methods: crimping, soldering, thermally bonding with glue, stitching.

[0031] According to yet another aspect of the present invention, the main board can include at least one contact area formed on the first surface and configured to form a support surface for the second end of at least one heat pipe.

[0032] According to another aspect of the present invention, at least one heat pipe may include a first end in thermal contact with the test unit, preferably abutting against the test unit; the at least one heat pipe may further include a second end in thermal contact with the space converter, preferably abutting against the space converter; in particular, at least one heat pipe may pass through the main board.

[0033] In this case, the at least one heat pipe may further include a diameter reduction section and a cross-section change point located inside the main board, the diameter reduction section extending from the cross-section change point and passing through the main board; the cross-section change point is preferably arranged at the part where the main board contacts the reinforcement.

[0034] According to another aspect of the present invention, at least one heat pipe may be of the active type, transferring heat to a liquid; in this case, the heat dissipation device may include at least one heat sink associated with the at least one heat pipe.

[0035] In particular, at least one heat pipe may have a first end associated with a first heat sink; the first heat sink may be arranged on the surface of the main board facing the test unit. The at least one heat pipe may further have a second end associated with a second heat sink; the second heat sink may be arranged on the surface of the space converter facing the probe head.

[0036] According to this aspect of the present invention, at least one heat pipe may include an evaporation chamber at its second end, in which a liquid flows, and the heat generated by the probe card is converted into steam; the at least one heat pipe may further include a condensation chamber arranged at its first end. In this way, the steam flows along the at least one heat pipe from the evaporation chamber to the condensation chamber, where the steam is again converted into a liquid, releasing heat to the first heat sink; then, the liquid returns to the evaporation chamber.

[0037] According to another aspect of the present invention, at least one heat pipe may include a first end in thermal contact with the test unit, preferably abutting against the test unit; the at least one heat pipe may further include a second end in thermal contact with the probe head.

[0038] According to this aspect of the present invention, the second end of the heat pipe may be located inside the housing of the probe head.

[0039] In particular, the second end of the at least one heat pipe may be located in the air gap inside the probe head.

[0040] The heat dissipation device may further include a heat storage element associated with the second end of the at least one heat pipe.

[0041] According to another aspect of the present invention, the heat dissipation device may further include a coating arranged on the guide of the probe head, preferably in contact with the second end of the at least one heat pipe.

[0042] In particular, the coating can be made of a material with a thermal conductivity greater than 100 W / (m·K), preferably greater than 500 W / (m·K).

[0043] In addition, the coating can be made of a material selected from silicon nitride, silicon carbide, and CVD-D (chemical vapor deposition-diamond).

[0044] According to another aspect of the present invention, the heat dissipation device may further include a core formed inside the space converter. At least one heat pipe has a first end in thermal contact with the test unit and a second end in thermal contact with the core. The core can also be made of a material with a thermal conductivity greater than 100 W / (m·K), preferably greater than 500 W / (m·K).

[0045] According to this aspect of the present invention, the core may include a peripheral portion exposed to the air outside the space converter.

[0046] The core material can especially be made of a material with a Young's modulus greater than 30000 MPa, preferably greater than 1200000 MPa.

[0047] More specifically, the core can be made of a material selected from silicon nitride, silicon carbide, and CVD-D (chemical vapor deposition-diamond), preferably CVD-D.

[0048] According to another aspect of the present invention, the heat dissipation device may further include an air-cooled heat exchange structure, which includes at least one exchanger and a fan coil configured to generate cooling air for the exchanger; in addition, the heat dissipation device may also include a core made of a material with a thermal conductivity greater than 100 W / (m·K), preferably greater than 500 W / (m·K), which is arranged inside the space converter. In particular, the first end of at least one heat pipe can be in thermal contact with the exchanger; in addition, the second end of at least one heat pipe can be in thermal contact with the core.

[0049] According to yet another aspect of the present invention, the heat dissipation device may further include a liquid-cooled heat exchange structure, which includes at least one microfluidic channel. The microfluidic channel can be formed inside at least one heat pipe and the space converter; in addition, a cooling liquid can flow through the microfluidic channel. The heat dissipation device may also include a core made of a material with a thermal conductivity greater than 100 W / (m·K), preferably greater than 500 W / (m·K), which is arranged inside the space converter; appropriately, the first end of at least one heat pipe is located at one end of the microfluidic channel, and the second end is in thermal contact with the core.

[0050] Finally, according to this aspect of the present invention, the liquid-cooled heat exchange structure may include a plurality of microfluidic channels provided inside at least one heat pipe and the space converter.

[0051] Hereinafter, exemplary embodiments of the present invention will be described by way of non-limiting examples with reference to the accompanying drawings, based on which the features and advantages of the probe card of the present invention will become apparent. Description of the Drawings

[0052] In the figures:

[0053] - Figure 1 A schematic cross-sectional view of a probe card according to an embodiment of the present invention is shown;

[0054] - Figure 2 A schematic cross-sectional view of a probe card according to another embodiment of the present invention is shown;

[0055] - Figure 3A A schematic cross-sectional view of a probe card according to another alternative embodiment of the present invention is shown, and Figures 3B - 3D schematically shows Figure 3A the components included in the probe card; and

[0056] - Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 A schematic cross-sectional view of a probe card according to a further alternative embodiment of the present invention is shown. Detailed Description of the Invention

[0057] Referring to the accompanying drawings, and in particular Figure 1 , the probe card manufactured according to the present invention is generally designated by the reference numeral 10 and includes at least one probe head provided with a plurality of contact probes for testing an electronic device (in particular an electronic device integrated on a wafer).

[0058] It should be noted that the drawings are schematic views of the probe card according to the present invention, not drawn to scale, but are drawn to emphasize the important features of the present invention.

[0059] In addition, several aspects of the present invention exemplarily shown in the drawings can obviously be combined with each other and interchanged in different embodiments.

[0060] In addition, in several embodiments shown in the figures and described below, elements having the same structure and function are labeled with the same alphanumeric reference.

[0061] In the following description, relative terms such as "above", "below", "upward", "downward", "upper", "lower", etc. will be used to describe the solution shown in the drawings, which is only for the sake of simplifying the description.

[0062] Finally, expressions referring to specific geometries (circular, rectangular) or element arrangements (parallel, orthogonal, contiguous), as well as the term "substantially", should always be understood in relation to physical elements rather than geometric abstractions, and thus the tolerances introduced when transitioning from pure mathematical / geometric concepts to practical applications must always be taken into account.

[0063] In particular, as Figure 1 shown, the probe card 10 includes a probe head 11 that houses a plurality of contact probes 1. The illustrated probe head 11 belongs to the unlocked vertical probe type and includes at least an upper plate or guide 2 and a lower plate or guide 3, which respectively have upper guide holes 2A and lower guide holes 3A through which the contact probes 1 slide.

[0064] In the technical field of the present invention, the term "lower guide" refers to the guide closer to the device under test, and the term "upper guide" refers to the guide closer to the test device connected to the probe card 10 including the probe head 11, which is mounted like the end element of the test device when the probe card 10 and the probe head 11 are in the working state.

[0065] In Figure 1 the illustrated example, the probe head 11 further includes an intermediate plate or guide 4, arranged parallel between the upper guide 2 and the lower guide 3, particularly close to the latter, and the intermediate guide 4 is also provided with intermediate guide holes 4A through which the contact probes 1 can slide. The above-described three-guide embodiment is only an example, and the probe head 11 can include any number of guides greater than or equal to one.

[0066] The probe head 11 further includes a housing element or enclosure 5 for integrally connecting the upper guide 2, the lower guide 3, and the intermediate guide 4 to each other and enclosing the contact probes 1 therein. Inside the enclosure 5, a free space or air gap 6 is defined, particularly between the upper guide 2 and the intermediate guide 4, and the air gap 6 allows the contact probes 1 to bend and deform during the operation of the probe head 11.

[0067] Each contact probe 1 includes at least one first end or contact tip 1A for abutting against a corresponding contact pad 13A of the device under test 13 (especially a device integrated on a semiconductor wafer 12) to establish the required contact (especially electrical contact) between the contact probes 1 of the probe head 11 and the contact pads 13A of the device under test 13.

[0068] Each contact probe 1 also includes a second end or contact head 1B for making contact with the main board 15 or the main PCB in order to establish a connection with the board of a test device (also referred to as test unit 17). A rod-shaped probe body 1C is located between the contact head 1B and the contact tip 1A and is arranged substantially along the longitudinal extension direction of the contact probe 1, particularly orthogonally to the plane π on which the semiconductor wafer 12 is located, on which the device under test 13 is integrated, i.e., along Figure 1 the Z-axis of the local coordinate system.

[0069] The upper guide 2, the lower guide 3, and the intermediate guide 4 are plate-shaped elements that are arranged parallel to each other and parallel to the plane π of the semiconductor wafer 12 and thus also parallel to the plane of the device under test 13. Compared with the prior art, appropriately, the upper guide 2, the lower guide 3, and the intermediate guide 4 are displaced relative to each other along a direction tangential to the plane π of the semiconductor wafer 12 (i.e., along Figure 1 the x-axis direction of the local coordinate system) in order to impose a preferential bending direction on the contact probe 1. Due to this offset of the guides, the guide holes in which the same contact probe is formed and received become misaligned with respect to the direction orthogonal to the plane π of the semiconductor wafer 12 (i.e., along Figure 1 the Z-axis of the local coordinate system), which forces the probe body 1C of the contact probe 1 to bend and determines its said preferential bending direction.

[0070] The probe card 10 further includes an intermediate board disposed between the probe head 11 and the main board 15, which is configured to perform a spatial transformation (particularly the distribution of contact pads on its opposite faces) and is thus referred to as a spatial converter 14.

[0071] The spatial converter 14 has a first face FA facing the main board 15, which is the upper surface according to Figure 1 the local coordinate system and includes a first plurality of contact pads (also denoted as tester-side pads 4A). The spatial converter 14 also has a second face FB facing the probe head 11, which is the lower surface according to Figure 1 the local coordinate system and includes a second plurality of contact pads (also denoted as probe-side pads 14B) against which the contact head 1B of the contact probe 1 abuts, and the probe-side pads 14B are connected to the tester-side pads 14A through appropriate metallization or metal tracks 14C inside the spatial converter 14.

[0072] Finally, the probe card 10 includes a stiffener 16 connected to the main board 15, which is configured to improve the flatness of the main board 15 and prevent it from bending, particularly during the operation of the probe card 10, i.e., when the temperature rises during the test operation.

[0073] In addition, a connector 18 (particularly a clamping screw) is also used to fix the test unit 17 and the probing card 10, particularly the main board 15, together.

[0074] During the operation of the probe card 10, i.e., when testing the device under test 13 integrated on the semiconductor wafer 12, several components of the probe card 10 become heat sources, in particular:

[0075] - A first heat flow H1 is exchanged between the semiconductor wafer 12 (especially the device under test 13 integrated therein) and the probe head 11;

[0076] - A second heat flow H2 is exchanged between the probe head 11 and the space converter 14;

[0077] - A third heat flow H3 is exchanged between the probe head 11 and the main board 15 through the air around the probe head 11 inside the probe card 10;

[0078] - A fourth heat flow H4 is formed inside the space converter 14 and flows to the main board 15; and

[0079] - A fifth heat flow H5 is formed inside the main board 15 and flows to the reinforcement 16.

[0080] The first heat flow H1 is defined as a functional heat flow and is related to the test operation and the signals exchanged by the contact probes 1 of the probe head 11, which are transmitted to the contact pads 13A of the device under test 13 integrated on the semiconductor wafer 12 in order to test the said device.

[0081] The second heat flow H2 is caused by the heating of the contact probes 1 inside the probe head 11 under the Joule effect, and this heat is always generated by the signals transmitted through the said probes, and is mainly transmitted to the space converter 14 through the contact of the contact heads 1B of the contact probes 1 with the probe side pads 14B of the space converter 14.

[0082] The third heat flow H3 is related to the heating of the air inside the probe card 10, especially the heat transfer generated due to the overheating of the support structure (chuck) of the semiconductor wafer 12 during the test operation.

[0083] The fourth heat flow H4 and the fifth heat flow H5 are always caused by the Joule effect and are generated inside the space converter 14 and the main board 15 respectively due to the signals transmitted inside the said components.

[0084] Other components of the probe card 10 are responsible for heat dissipation, in particular:

[0085] - The air existing between the main board 15 and the test unit 17 generates a first heat dissipation flow F1 and flows towards the test unit 17;

[0086] - The connector 18 generates a second heat dissipation flow F2 and flows towards the test unit 17; and

[0087] - A third heat dissipation flow F3 is formed in the contact area between the reinforcement member 16 and the test unit 17, and the third heat dissipation flow F3 also flows towards the test unit 17.

[0088] The space converter 14 and the probe head 11 are the components in the probe card 10 that are most vulnerable to high-temperature stress.

[0089] Advantageously, according to the present invention, the probe card 10 further includes a heat dissipation device 20, which can improve the heat exchange of the probe card 10 and reduce the problems related to overheating of the components of the probe card 10.

[0090] According to Figure 1 In the first embodiment shown, the heat dissipation device 20 includes at least one heat pipe 19 (a pair of heat pipes 19 in the example in the figure) arranged in the reinforcement member 16, which can make the main board 15 and the test unit 17 in thermal contact. Obviously, the presence of two heat pipes 19 in the heat dissipation device 20 is only a non-limiting example, and the heat dissipation device 20 can include any number of heat pipes 19 (more than one).

[0091] In particular, each heat pipe 19 includes a first end 19A in thermal contact with the test unit 17 (preferably leaning against the test unit 17) and a second end 19B in thermal contact with the main board 15 (preferably leaning against the main board 15). The first end 19A is located on the first surface FC of the reinforcement member 16 (in particular Figure 1 the upper surface of the local coordinate system in the figure, that is, the surface facing the test unit 17), and the second end 19B is located on the second surface FD of the reinforcement member 16 (in particular Figure 1 the lower surface of the local coordinate system in the figure, that is, the surface facing the main board 15). The position of each heat pipe 19 is such that the first end 19A is located at the part of the first surface FC of the reinforcement member 16 in contact with the test unit 17, and the second end 19B is located at the part of the second surface FD of the reinforcement member 16 in contact with the main board 15 to achieve a thermal connection between the main board 15 and the test unit 17. In addition, the first end 19A has an enlarged support structure on the first surface FC of the reinforcement member 16.

[0092] Suitably, the heat pipes 19 of the heat dissipation device 20 can generate an additional heat dissipation flow F*, thereby significantly improving the dissipation of the heat generated inside the probe card 10. For this purpose, the heat pipes 19 can be made of materials with a high thermal conductivity coefficient λ, and these materials can be selected from metals or inorganic materials.

[0093] Preferably, the heat pipes 19 are made of materials with a thermal conductivity coefficient λ greater than 100 W / (m·K), preferably greater than 500 W / (m·K).

[0094] More specifically, the materials of the heat pipes 19 can be selected from copper, aluminum, aluminum nitride, silicon nitride, silicon carbide, and CVD-D (chemical vapor deposition - diamond).

[0095] The second end 19B of each heat pipe 19 abuts against the first face FE of the main board 15 (specifically according to Figure 1 the upper surface of the local coordinate system), and the first face FE of the main board 15 is in contact with the second face FD of the reinforcement 16. As an alternative, the second end 19B can be integrally connected to the first face FE of the main board 15 by welding or thermal adhesive bonding, or even by seam welding (crimping).

[0096] In a preferred embodiment, the heat pipe 19 is constituted by a metal (such as copper) column, and the composite material is realized by crimping, so that the first and second ends 19A and 19B of the heat pipe 19 are lapped to form a final planar structure and an integral block with higher vertical heat conduction performance.

[0097] In addition, appropriate contact areas or heat dissipation pads 15E can be arranged on the first face FE of the main board 15 to form a support surface for the second end 19B of the heat pipe 19.

[0098] It should be emphasized that due to the presence of the heat dissipation device 20 and its heat pipes 19, a thermal connection is achieved between the main board 15 and the test unit 17, the thermal conductivity of the main board 15 is improved, and the heat generated during the operation of the probe card 10 is also basically better dispersed.

[0099] According to an alternative embodiment, the heat pipes 19 of the heat dissipation device 20 can be formed to completely penetrate the main board 15 and be in thermal contact with the space converter 14, as Figure 2 shown.

[0100] In addition, each heat pipe 19 can be formed inside the main board 15 to include a diameter reduction section 19S. In this case, each heat pipe 19 includes a first end 19A arranged on the first face FC of the reinforcement 16, and a second end 19B arranged on the second face FF of the main board 15 opposite to the first face FE (specifically according to Figure 2 the lower surface of the local coordinate system), the second face FF is in contact with the space converter 14, and a cross-section change point 19C arranged on the first face FE of the main board 15, and the diameter reduction section 19S extends from this cross-section change point 19C and penetrates the main board 15.

[0101] In this case, appropriate contact areas or heat pads 15F can also be arranged on the second face FF of the main board 15 to form a support surface for the second end 19B of the heat pipe 19.

[0102] The heat pipe 19 is preferably made of a material with a high thermal conductivity coefficient λ, and these materials can be selected from metals or inorganic materials, and the thermal conductivity coefficient λ of the materials is greater than 100 W / (m·K), preferably greater than 500 W / (m·K), as described above, and can be selected from copper, aluminum, aluminum nitride, silicon nitride, silicon carbide, and CVD-D (chemical vapor deposition - diamond).

[0103] As described in the embodiments in conjunction with Figure 1 and Figure 2 above, the heat pipe 19 is generally in the form of a solid metal rod and is commonly referred to as a passive heat pipe.

[0104] An active heat pipe 19 can also be used to transfer heat to a liquid. In this case, in addition to at least one heat pipe 19, the heat dissipation device 20 further includes at least one radiator associated with the heat pipe 19 for transferring heat to the outside of the heat pipe 19.

[0105] More specifically, in the example shown in Figure 3A , the heat dissipation device 20 includes a pair of heat pipes 19, each heat pipe 19 having a first end 19A associated with a first radiator 21A disposed on the main board 15, particularly on its first face FE facing the test unit 17, and a second end 19B associated with a second radiator 21B disposed on the space converter 14, particularly on its second face FB facing the probe head 11. Appropriately, the first radiator 21A is positioned on a portion of the first face FE of the main board 15 that does not contact the reinforcement 16, and the second radiator 21B is positioned on a portion of the second face FB of the space converter 14 where there is no probe side pad 14B (the contact head 1B of the contact probe 1 of the probe head 11 abuts against the probe side pad 14B), so as not to interfere with the operation of the probe card 10 and the probe head 11 contained therein.

[0106] As Figure 3B shown, each active heat pipe 19 includes an evaporation chamber 22B at its second end 19B, and the liquid flowing in the evaporation chamber 22B is converted into steam due to the heat generated by the probe card 10 and is transported along the heat pipe 19 to the condensation chamber 22A disposed at the first end 19A. In the condensation chamber 22A, the steam is again converted into liquid, releasing the heat to the first radiator 21A disposed on the main board 15, and then the liquid returns to the evaporation chamber 22B to restart the process.

[0107] Figure 3C The heat dissipation device 20 thus obtained is schematically illustrated in Figure 3D wherein the first radiator 21A is also illustrated in more detail, and the second end 19B of the heat pipe 19 associated with the second radiator 21B is also shown.

[0108] According to Figure 4 another alternative embodiment schematically shown, the heat pipe 19 can also be formed to penetrate the housing 5 of the probe head 11 and be in thermal contact therewith to eliminate the heat generated in the probe head 11 and cool the housing 5 itself. In particular, in this case, the second end 19B of the heat pipe 19 is disposed inside the housing 5.

[0109] The heat dissipation device 20 may further include a coating 23 made of a material with a thermal conductivity λ greater than 100 W / (m·K), preferably greater than 500 W / (m·K), disposed on a guiding member of the probe head 11 (also on the housing 5) and in contact with the second end 19B of the heat pipe 19. More specifically, the coating 23 may be made of silicon nitride, silicon carbide, and CVD-D (chemical vapor deposition - diamond) materials.

[0110] In Figure 4 the example of, the coating 23 is disposed on the surface of the intermediate guiding member 4 (especially Figure 4 above the local coordinate system of), and is also extended on the housing 5. The second end 19B of each heat pipe 19 is in thermal contact with the coating 23 within the housing 5.

[0111] As an alternative, as Figure 5 shown, the heat pipe 19 may be formed in the air gap 6 outside the housing 5 but inside the probe head 11. In particular, the second end 19B of the heat pipe 19 is disposed within the air gap 6 and is appropriately disposed in an area where the heat pipe 19 during normal operation of the probe card 10 (even when the contact probe 1 bends and deforms when its contact tip 1A presses against the contact pad 13A of the device under test) has no risk of contacting the contact probe 1. In this case, a coating 23 may also be provided, which is made of a material with a high thermal conductivity λ, the thermal conductivity being greater than 100 W / (m·K), preferably greater than 500 W / (m·K). The coating 23 may be made of silicon nitride, silicon carbide, and CVD-D (chemical vapor deposition - diamond) materials and is disposed on a guiding member of the probe head 11 in contact with the second end 19B of the heat pipe 19.

[0112] In Figure 5 the example of, the coating 23 is disposed on a surface of the intermediate guiding member 4 (especially according to Figure 5 the local coordinate system of), the second end 19B of each heat pipe 19 is in thermal contact with the coating 23 within the air gap 6, preferably in press contact with the coating 23, and the coating 23 also extends into the air gap 6. Although not shown in the figure, the coating 23 may also be formed on the part of the intermediate guiding member 4 located in the air gap 6 without extending the coating 23 to the housing 5.

[0113] The heat dissipation device 20 may also be designed to include a heat pipe 19, the second end 19B of the heat pipe 19 being disposed within the air gap 6 and associated with a heat storage element 24B. For example, as Figure 6 shown, the heat storage element 24B is disposed on a guiding member of the probe head 11 (such as the upper guiding member 2). In particular, in Figure 6In the example, the heat storage element 24B is arranged on the surface of the guide member facing the air gap 6 (more specifically, on the lower surface of the upper guide member 2 according to the local coordinate system of Figure 6 ).

[0114] Suitably, the heat storage element 24B helps to collect the heat generated inside the probe head 11 for subsequent elimination, thereby improving the thermal management of the entire probe card 10. In this case, a coating with high thermal conductivity (not shown in Figure 4 and Figure 5 ) can also be used on one of the guide members (such as the intermediate guide member 4 in the example) to improve the heat conduction from inside the probe head 11 to the heat pipe 19, particularly to the heat storage element 24B located on the intermediate guide member 4. Figure 6 .

[0115] In Figure 7 another alternative embodiment shown, the heat dissipation device 20 includes a core 25 formed inside the space converter 14; in particular, the space converter 14 can be in a multi-layer form and includes the core 25. Suitably, the core 25 is made of a material having a high thermal conductivity coefficient λ, that is, the thermal conductivity coefficient λ is greater than 100 W / (m·K), preferably greater than 500 W / (m·K). In addition, the second end 19B of the heat pipe 19 is formed in thermal contact with the core 25, thereby improving the heat transfer from inside the space converter 14 to the heat pipe 19.

[0116] The core 25 can also be designed to include a peripheral portion 25C that is exposed relative to the space converter 14 (or relative to other layers constituting the space converter 14 if it is in a multi-layer form). The peripheral portion 25C can further help dissipate the heat from inside the space converter 14 due to contact with the air around the probe card 10. According to an alternative embodiment not shown, a conductive layer can be arranged on the opposite surface of the exposed peripheral portion 25C of the core 25 to further promote the dissipation of heat in the air.

[0117] The core 25 is made of a material with high thermal conductivity, which particularly helps to optimally collect and subsequently dissipate the heat generated in the space converter 14 during the test operation of the probe card 10, and also helps to collect and dissipate the heat generated in the probe head 11, especially through the contact probe 1 therein connected to the space converter 14.

[0118] Suitably, the core body 25 can be made of a material with high stiffness (i.e., having a high tensile elastic modulus or Young's modulus E), especially greater than 30,000 MPa, preferably greater than 1,200,000 MPa, so as to serve as the mechanical support of the spatial converter 14. The spatial converter 14 can include a plurality of layers that are suitably overlapped with each other and the core body 25, and the mechanical support for the plurality of layers is actually provided by the core body 25.

[0119] In addition, the core body 25 is made of a non-conductive material and does not interfere with the electrical operation of the spatial converter 14.

[0120] The core body 25 can in particular be made of silicon nitride, silicon carbide or CVD-D (chemical vapor deposition - diamond) (preferably CVD-D). These materials are basically dielectric materials, having a relatively high thermal conductivity coefficient λ and sufficient stiffness to support the layers of the spatial converter 14, especially the organic layers that form an organic multi-layer (MLO) or the metal and ceramic layers that form a ceramic-based multi-layer or MLC (multi-layer ceramic).

[0121] The core body 25 itself can also be formed by combining multiple layers of different materials to improve the mechanical properties of the core body 25 while ensuring a good level of heat exchange. Among the materials used to form the layers of the core body 25, silicon nitride, silicon carbide and CVD-D (chemical vapor deposition - diamond) can also be used, just to name a few.

[0122] In addition, as Figure 8 shown, the heat dissipation device 20 can also include an air-cooled heat exchange structure 26, mainly including an exchanger 26A at the first end 19A of the heat pipe 19 and a corresponding fan coil unit 26B. The fan coil unit is configured to generate cooling air for the exchanger 26A. In Figure 8 the example shown, the second end 19B of the heat pipe 19 is in thermal contact with the core body 25 formed in the spatial converter 14, preferably leaning against the core body 25.

[0123] As an alternative, as Figure 9 shown, the heat dissipation device 20 can include a liquid-cooled heat exchange structure in the form of a microfluidic channel 27 formed inside the heat pipe 19 and the spatial converter 14. The cooling liquid 28 leads from the inlet nozzle 27A to the outlet nozzle 27B, preferably formed on the first ends 19A of different heat pipes 19. In Figure 9 the example shown, the respective second ends 19B of the heat pipes 19 are in thermal contact with the core body 25 formed in the spatial converter 14, preferably leaning against the core body 25.

[0124] The microfluidic channel 27 passing through the heat pipe 19 and the spatial converter 14 to allow the cooling liquid 28 to pass through can be formed by laser drilling. Preferably, the microfluidic channel 27 is formed close to the core body 25 to improve the heat exchange with the core body 25.

[0125] The cooling liquid 28 transported by the microfluidic channel 27 can achieve liquid cooling. In addition to the heat pipe 19, it can also affect the entire spatial converter 14, thereby significantly improving the heat exchange efficiency of the spatial converter 14, especially its core 25.

[0126] Obviously, a plurality of microfluidic channels can be provided in the heat pipe 19 and the spatial converter 14 to transport the cooling liquid 28.

[0127] In summary, advantageously, according to the present invention, a probe card provided with a heat dissipation device including a heat pipe can effectively dissipate the heat generated in the probe card, especially in the case of using a power signal for a test operation. In this way, the overall thermal management of the probe card is improved, thereby reducing the problem of failure caused by the deformation of the components constituting the probe card due to the heat generated inside the probe card during operation.

[0128] Therefore, such a probe card is suitable for situations where the overall temperature of the probe card significantly increases during testing, can ensure the correct operation of the probe card, and avoid deformation of the components constituting the probe card (such as probe heads and spatial converters), and such deformation may affect the good results of the test.

[0129] If the heat dissipation device includes an active heat pipe associated with a heat sink, the heat dissipation effect will be further improved. In addition, when the heat dissipation device includes an air or liquid cooling heat exchange structure, the temperature performance of the probe card will also be improved.

[0130] In addition, by using a spatial converter in the probe card, the spatial converter is provided with a core made of a high thermal conductivity material (which may include a peripheral portion exposed to the air), thereby improving the heat exchange of the entire probe card; if the core is appropriately made of a material with sufficient stiffness, it can also provide mechanical support for other layers (especially the organic layers forming the spatial converter itself).

[0131] Obviously, in order to meet accidental and specific requirements, those skilled in the art can make several modifications and substitutions to the above-mentioned probe card, and all of these fall within the protection scope of the present invention defined by the following claims.

Claims

1. A probe card (10) configured to be mounted in a test apparatus of an electronic device and to contact a test unit (17) of the test apparatus, the probe card (10) including at least one probe head (11) that houses a plurality of contact probes (1) and is disposed between a device under test (13) and a space converter (14), the space converter (14) being in turn in contact with a main board, the main board (15) being configured to be connected to the test unit (17) and being provided with a reinforcement member (16), characterized in that, The probe card includes a heat dissipation device (20), which is provided with at least one heat pipe (19). The heat pipe (19) is used to thermally connect the probe card (10) and the test unit (17), and dissipate the heat generated inside the probe card (10) during operation.

2. The probe card (10) according to claim 1, characterized in that, The at least one heat pipe (19) is a passive type and is made of a material with a thermal conductivity greater than 100 W / (m·K).

3. The probing card (10) according to claim 2, characterized in that, The at least one heat pipe (19) is made of a material with a thermal conductivity greater than 500 W / (m·K).

4. The probe card (10) according to claim 2, characterized in that, The at least one heat pipe (19) is made of a material selected from copper, aluminum, aluminum nitride, silicon nitride, silicon carbide, and CVD-D (chemical vapor deposition-diamond).

5. The probe card (10) according to claim 2, characterized in that, The at least one heat pipe (19) includes a first end (19A) in thermal contact with the test unit (17) and a second end (19B) in thermal contact with the main board (15).

6. The probe card (10) according to claim 5, characterized in that, The first end (19A) abuts against the test unit (17), and the second end (19B) abuts against the main board (15).

7. The probing card (10) according to claim 5, characterized in that, The first end (19A) of the at least one heat pipe (19) is arranged at a part where the first surface (FC) of the reinforcement member (16) contacts the test unit (17), and the second end (19B) of the at least one heat pipe (19) is arranged at a part where the second surface (FD) of the reinforcement member (16) contacts the main board (15).

8. The probe card (10) according to claim 5, characterized in that, The second end (19B) of the at least one heat pipe (19) is connected to the first surface (FE) of the main board (15) by one of the following methods: crimping, welding, thermal adhesive bonding, stitching.

9. The probing card (10) according to claim 8, characterized in that, The main board (15) includes at least one contact area (15E), which is formed on the first surface (FE) and is configured to form a support surface for the second end (19B) of the at least one heat pipe (19).

10. The probing card (10) according to claim 2, characterized in that, The at least one heat pipe (19) includes a first end (19A) in thermal contact with the test unit (17) and a second end (19B) in thermal contact with the space converter (14). The at least one heat pipe (19) passes through the main board (15).

11. The probe card (10) according to claim 10, characterized in that, The first end (19A) abuts against the test unit (17), and the second end (19B) abuts against the space converter (14).

12. The probe card (10) according to claim 10, characterized in that, The at least one heat pipe (19) includes a diameter reduction section (19S) and a cross-section change point (19C) inside the main board (15). The diameter reduction section (19S) extends from the cross-section change point through the main board (15).

13. The probing card (10) according to claim 12, characterized in that, The cross-section change point (19C) is arranged at a part where the main board (15) contacts the reinforcement member (16).

14. The probe card (10) according to claim 1, characterized in that, The at least one heat pipe (19) is an active type that transfers heat to a liquid, and the heat dissipation device (20) includes at least one radiator associated with the at least one heat pipe (19).

15. The probe card (10) according to claim 14, characterized in that, The at least one heat pipe (19) has a first end (19A) and a second end (19B), the first end (19A) being associated with a first heat sink (21A) disposed on a face (FE) of the main board (15) facing the test unit (17); the second end (19B) being associated with a second heat sink (21B) disposed on a face (FB) of the space converter (14) facing the probe head (11).

16. The probe card (10) according to claim 15, characterized in that, The at least one heat pipe (19) includes an evaporation chamber (22B) at its second end (19B) in which a liquid flows, the liquid being converted into vapor by heat generated by the probe card (10) and being transported along the at least one heat pipe (19) to a condensation chamber (22A) provided at the first end (19A) of the at least one heat pipe (19), in which the vapor is again converted into a liquid, releasing heat to the first heat sink (21A), and then the liquid returns to the evaporation chamber (22B).

17. The probe card (10) according to claim 2, characterized in that, The at least one heat pipe (19) includes a first end (19A) in thermal contact with the test unit (17) and a second end (19B) in thermal contact with the probe head (11).

18. The probe card (10) according to claim 17, wherein The second end (19B) of the at least one heat pipe (19) is located within a housing (5) of the probe head (11).

19. The probe card (10) according to claim 17, characterized in that, The second end (19B) of the at least one heat pipe (19) is located in an air gap (6) inside the probe head (11).

20. The probe card (10) according to claim 19, characterized in that, The heat dissipation device (20) further includes a heat storage element (24B) associated with the second end (19B) of the at least one heat pipe (19).

21. The probe card (10) according to claim 17, characterized in that, The heat dissipation device (20) further includes a coating (23) disposed on guides (2, 3, 4) of the probe head (11).

22. The probe card (10) according to claim 21, wherein, The coating (23) is in contact with the second end (19B) of the at least one heat pipe (19).

23. The probe card (10) according to claim 21, characterized in that, The coating (23) is made of a material having a thermal conductivity greater than 100 W / (m·K).

24. The probe card (10) according to claim 23, characterized in that, The coating (23) is made of a material having a thermal conductivity greater than 500 W / (m·K).

25. The probe card (10) according to claim 23, characterized in that, The coating (23) is made of a material selected from silicon nitride, silicon carbide, and CVD-D (chemical vapor deposition - diamond).

26. The probe card (10) according to claim 2, characterized in that, The heat dissipation device (20) further includes a core (25) formed inside the space converter (14), the at least one heat pipe (19) having a first end (19A) in thermal contact with the test unit (17) and a second end (19B) in thermal contact with the core (25), the core (25) being made of a material having a thermal conductivity greater than 100 W / (m·K).

27. The probe card (10) according to claim 26, characterized in that, The core (25) includes a peripheral portion (25C) exposed to air outside the space converter (14).

28. The probe card (10) according to claim 26, wherein, The core (25) is made of a material having a Young's modulus value greater than 30000 MPa.

29. The probe card (10) according to claim 26, characterized in that, The core (25) is made of a material selected from silicon nitride, silicon carbide, and CVD-D (chemical vapor deposition - diamond).

30. The probe card (10) according to claim 2, characterized in that, The heat dissipation device (20) further includes an air-cooled heat exchange structure (26), the air-cooled heat exchange structure including at least one exchanger (26A), a fan coil unit (26B) configured to generate cooling air for the exchanger (26A), and a core (25) made of a material with a thermal conductivity greater than 100 W / (m·K) and disposed inside the space converter (14), the at least one heat pipe (19) having a first end (19A) in thermal contact with the exchanger (26A) and a second end (19B) in thermal contact with the core (25).

31. The probe card (10) according to claim 2, characterized in that, The heat dissipation device (20) further includes a liquid-cooled heat exchange structure, the liquid-cooled heat exchange structure including at least one microfluidic channel (27), and a core (25) made of a material with a thermal conductivity greater than 100 W / (m·K) and disposed inside the space converter (14), the microfluidic channel being formed inside the at least one heat pipe (19) and the space converter (14) and a cooling liquid (28) flowing through the microfluidic channel, the at least one heat pipe (19) having a first end (19A) located at an end (27A, 27B) of the microfluidic channel (27), and a second end (19B) in thermal contact with the core (25).

32. The probe card (10) according to claim 31, characterized in that, The liquid-cooled heat exchange structure includes a plurality of microfluidic channels formed inside the at least one heat pipe (19) and the space converter (14).

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