Test probe card

Abstract

The invention relates to the technical field of wafer testing, in particular to a test probe card. The test probe card includes: a substrate having a substrate top surface and a substrate bottom surface; a mounting groove is formed in the bottom of the peripheral part of the base plate and is sunken from the bottom surface of the base plate to the top surface of the base plate; a guide hole conductive structure used for being conductively connected with a testing device is arranged in the peripheral part of the substrate, and the guide hole conductive structure is provided with an outer connecting part exposed at the groove top wall of the mounting groove; and the probe is fixedly installed at the bottom of the substrate, the probe is in conductive connection with the external connection part of the guide hole conductive structure through a flexible circuit board, and a part of the flexible circuit board is fixedly installed in the installation groove. In the invention, the electric connection between the probe and the testing device is realized by utilizing the guide hole conductive structure in the substrate, and the electric connection between the probe and the testing device is realized without a plurality of layers of special conductive traces, so that the special conductive traces are prevented from being formed by etching in the substrate, and the production cost can be obviously reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer testing, and particularly relates to a test probe card. Background Art

[0002] A method for testing integrated circuits on a wafer is to bring multiple probes on a substrate into contact with test pads on the wafer. The probes will transmit test signals from the wafer, and a test device will receive the measurement signals. Finally, the test device analyzes the received test signals to determine whether there are faults in the integrated circuits. With the development of high-frequency and high-density integrated circuits, the probes on the substrate not only need to be arranged more densely, but also the substrate must have an anti-interference design so that the probes on the substrate can avoid serious signal interference under high-speed frequency operation. The currently commonly used anti-interference design scheme is: shortening the length of the probes, and the probes are conductively connected to multi-layer dedicated conductive traces in the substrate through coaxial cables or flexible circuit boards capable of transmitting high-frequency signals.

[0003] In the above-mentioned existing anti-interference design scheme, multi-layer dedicated conductive traces must be provided in the substrate for signal connection with the coaxial cable or flexible circuit board. However, the conductive traces in the substrate are made by an etching process, so setting multi-layer dedicated conductive traces in the substrate will increase the overall production cost; and the more the number of conductive trace layers, the higher the overall production cost. Summary of the Invention

[0004] The object of the present invention is to solve the following technical problem: setting dedicated conductive traces for signal connection with the coaxial cable or flexible circuit board in the substrate will lead to an increase in production cost.

[0005] To achieve the above object, the present invention provides a test probe card, which includes: a substrate having a substrate top surface and a substrate bottom surface; an installation groove is provided at the bottom of the outer peripheral portion of the substrate, and the installation groove is recessed from the substrate bottom surface towards the substrate top surface; a via conductive structure for conductive connection with a test device is provided in the outer peripheral portion of the substrate, and the via conductive structure has an outer connection portion exposed at the top wall of the installation groove; and probes, the probes are fixedly installed at the bottom of the substrate, and the probes are conductively connected to the outer connection portion of the via conductive structure through a flexible circuit board, and a part of the flexible circuit board is fixedly installed in the installation groove.

[0006] In some embodiments, the flexible circuit board includes a first section disposed in the installation groove and a second section located outside the installation groove, and a part of the first section is attached to the top wall of the installation groove.

[0007] In some embodiments, the installation groove has a groove side wall near the middle of the substrate, and the included angle between the groove side wall and the groove top wall is an obtuse angle or a right angle, and another part of the first section is attached to the groove side wall.

[0008] In some embodiments, the outer peripheral portion of the substrate is configured to be supported by the carrier of the prober; and when the carrier supports the outer peripheral portion of the substrate, there is a gap between the carrier and the first section.

[0009] In some embodiments, an elastic member is disposed between the carrier and the flexible circuit board. The elastic member is located directly below the via conductive structure. The bottom surface of the elastic member contacts the carrier, and the top surface of the elastic member contacts the bottom surface of the first section.

[0010] In some embodiments, at least a portion of the second section is spaced apart from the bottom surface of the substrate.

[0011] In some embodiments, the top surface of the second section is parallel to the bottom surface of the substrate.

[0012] In some embodiments, the via conductive structure includes a via and a conductive component. The via extends along the thickness direction of the substrate. The conductive component is disposed in the via. A portion of the conductive component is exposed at the top wall of the mounting groove to form an external connection portion. The conductive component can be electrically connected to the test device.

[0013] In some embodiments, the via is a circular hole and the conductive component is cylindrical.

[0014] In some embodiments, the conductive component includes a signal transmission portion for transmitting signals and a grounding portion for shielding external interference signals from the signal transmission portion.

[0015] The above technical solution of the present invention has the following beneficial effects:

[0016] The probe is electrically connected to the test device through the flexible circuit board and the via conductive structure. Since the forming process of the via conductive structure is relatively simple, compared with realizing electrical connection by using multi-layer dedicated conductive traces formed by etching, using the via conductive structure to realize the electrical connection between the probe and the test device will result in lower production costs. Moreover, the via conductive structure is usually also disposed at a position where the influence on current transmission is small, such as the outer peripheral portion of the substrate. Therefore, the via conductive structure on the substrate can be fully utilized without additionally adding a via conductive structure on the substrate, further reducing the production cost. In short, in the present invention, the electrical connection between the probe and the test device is realized by using the via conductive structure in the substrate, without realizing the electrical connection between the probe and the test device through multi-layer dedicated conductive traces, avoiding etching dedicated conductive traces in the substrate, and significantly reducing the production cost. Description of the Drawings

[0017] Figure 1 is a schematic diagram of a test probe card in an embodiment of the present invention;

[0018] Figure 2 is a distribution schematic diagram of the flexible circuit board in an embodiment of the present invention;

[0019] Figure 3 It is a schematic diagram of the distribution of the flexible circuit board in another embodiment of the present invention;

[0020] Figure 4 It is a schematic diagram of the distribution of the conductive component in another embodiment of the present invention;

[0021] Figure 5 It is a schematic diagram of the distribution of the mounting groove in another embodiment of the present invention;

[0022] Figure 6 It is a bottom view schematic diagram of the substrate in an embodiment of the present invention.

[0023] Explanation of reference numerals

[0024] 1. Substrate; 11. Via conductive structure; 111. Conductive component; 112. Outer connection part; 12. Mounting groove; 121. Groove top wall; 122. Groove side wall; 13. Substrate top surface; 14. Substrate bottom surface;

[0025] 2. Probe;

[0026] 3. Flexible circuit board; 31. First section; 32. Second section;

[0027] 4. Carrier;

[0028] 5. Elastic member. Detailed implementation manners

[0029] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present invention, rather than limiting the present invention. For those skilled in the art, the present invention can be implemented without some of these specific details. The following description of the embodiments is only intended to provide a better understanding of the present invention by showing examples of the present invention.

[0030] Conductive traces and via conductive structures (vias) for conducting electricity are provided in the substrate (such as a PCB board).

[0031] Among them, the conductive trace is a circuit structure in the substrate for connecting electrical components. The conductive trace is formed by adding a copper layer on the substrate and etching away the unnecessary copper, and is used to establish a conductive connection on the same layer of the substrate. The formation of the conductive trace generally goes through processes such as laminating copper foil, applying photoresist, exposure, development, etching, stripping, and cleaning, and the quality of the conductive trace needs to be fully ensured during the forming process. Therefore, for each additional dedicated conductive trace, it will at least lead to an increase in the workload and complexity of the above-mentioned forming steps, thereby increasing the overall production cost. Especially, the more layers of conductive traces there are, the higher the overall production cost will be.

[0032] The via conductive structure is a structure for connecting conductive traces between different layers in the substrate. The via conductive structure allows current to be transmitted between multiple layers of the substrate, and is a key structure that can achieve multi-layer circuit connection. The forming process of the via conductive structure generally includes drilling and configuring the conductive structure, and the forming process is relatively simple. Therefore, the forming cost of the via conductive structure is much lower than that of the conductive trace. The via conductive structure is basically provided in the substrate, and is arranged at a position where the influence on current transmission is relatively small. Based on the structural characteristics and cost advantages of the via conductive structure, the present invention provides a technical solution for reducing production costs.

[0033] As Figures 1 to 6 shown, the present invention provides a test probe card, which includes a substrate 1 and probes 2. The substrate 1 has a substrate top surface 13 and a substrate bottom surface 14. An installation groove 12 is provided at the bottom of the outer peripheral portion of the substrate 1, and the installation groove 12 is recessed from the substrate bottom surface 14 towards the substrate top surface 13. A via conductive structure 11 for making a conductive connection with a test device is provided in the outer peripheral portion of the substrate 1, and the via conductive structure 11 has an outer connection portion 112 exposed at the groove top wall 121 of the installation groove 12. The probes 2 are fixedly installed at the bottom of the substrate 1, and the probes 2 are conductively connected to the outer connection portion 112 of the via conductive structure 11 through a flexible circuit board 3, and a part of the flexible circuit board 3 is fixedly installed in the installation groove 12.

[0034] In this embodiment, the probe 2 is electrically connected to the test device through the flexible circuit board 3 and the via conductive structure 11. Since the forming process of the via conductive structure 11 is relatively simple, compared with realizing electrical connection by using multi-layer dedicated conductive traces formed by etching, using the via conductive structure 11 to realize the electrical connection between the probe 2 and the test device will result in lower production costs. Moreover, the via conductive structure 11 is usually also arranged at a position where the influence on current transmission is small, such as the outer peripheral part of the substrate 1, etc. Therefore, the via conductive structure 11 on the substrate 1 can be fully utilized without additionally adding via conductive structures 11 on the substrate 1, further reducing the production costs. In short, in the present invention, the via conductive structure 11 in the substrate 1 is used to realize the electrical connection between the probe 2 and the test device, without realizing the electrical connection between the probe 2 and the test device through multi-layer dedicated conductive traces, avoiding etching dedicated conductive traces in the substrate 1, and can significantly reduce the production costs.

[0035] It should be noted that, with reference to Figures 1 to 5 , the top surface 13 of the substrate is the top surface of the substrate 1, and the bottom surface 14 of the substrate is the bottom surface of the substrate 1. Therefore, the top surface 13 of the substrate is located above the bottom surface 14 of the substrate. Thus, the installation groove 12 is recessed from the bottom surface 14 of the substrate towards the top surface 13 of the substrate, that is, the installation groove 12 is recessed from the bottom surface of the substrate 1 towards the top surface of the substrate 1.

[0036] It should also be noted that there are usually metal components of the needle tester (such as the carrier 4) below the outer peripheral part of the substrate 1. If this metal component is in direct contact with the flexible circuit board 3 or too close to it, the metal component will interfere with the electrical signals in the flexible circuit board 3. However, the substrate 1 is made of insulating material. Even if the substrate 1 is in contact with the flexible circuit board 3, the substrate 1 will not interfere with the electrical signals in the flexible circuit board 3. For example, an installation groove 12 is provided at the bottom of the outer peripheral part of the substrate 1, and a part of the flexible circuit board 3 can be arranged in the installation groove 12, so that the flexible circuit board 3 can keep a sufficient distance from the carrier 4, preventing the flexible circuit board 3 from contacting the carrier 4 or being too close to it, thereby preventing the metal component from interfering with the electrical signals in the flexible circuit board 3. In addition, fixing and installing the flexible circuit board 3 in the installation groove 12 can also facilitate the disassembly of the flexible circuit board 3. For example, the flexible circuit board 3 can be embedded and fixed in the installation groove 12 by means of snap connection. Another example is that the flexible circuit board 3 can be detachably connected to the installation groove 12 through fasteners.

[0037] In some embodiments, there is a seamless conductive connection between the flexible circuit board 3 and the external connection part 112, so as to make the impedance between the flexible circuit board 3 and the external connection part 112 stable and ensure the stable transmission of current or signals. [[ID=(13]]

[0038] In some embodiments, such as Figures 2 to 6As shown, the installation groove 12 extends from the outer peripheral edge of the substrate 1 towards the middle of the substrate 1, and this extending direction is also the length direction L of the installation groove 12.

[0039] In some embodiments, the installation groove 12 can be formed by milling to fully expose the via conductive structure 11.

[0040] As Figures 1 to 4 shown, in some embodiments of the present invention, the flexible circuit board 3 includes a first section 31 disposed in the installation groove 12 and a second section 32 located outside the installation groove 12, and a part of the first section 31 is attached to the groove top wall 121 of the installation groove 12.

[0041] Specifically, the first section 31 is the part closest to the outer connection portion 112. If the first section 31 is in a rough and uneven curved shape, such as extending in a wave shape, it is likely to cause a problem of a sharp increase in transient impedance near the outer connection portion 112. However, attaching a part of the first section 31 to the groove top wall 121 of the installation groove 12 can keep the first section 31 as flat as possible, thereby avoiding the problem of a sharp increase in transient impedance near the outer connection portion 112. Moreover, attaching a part of the first section 31 to the groove top wall 121 of the installation groove 12 can keep a sufficient distance between the first section 31 and the metal components (of the needle tester) below the substrate 1, preventing interference with the electrical signals in the flexible circuit board 3 due to contact between the metal components and the first section 31 or being too close.

[0042] In some embodiments, the first section 31 can be disposed in the installation groove 12 by means such as embedding, clamping, locking, bonding, or welding, and the present invention is not limited thereto. In some other embodiments, the first section 31 can also be further connected to the substrate 1 through a plurality of fasteners to make the connection of the first section 31 firm.

[0043] In some embodiments, the depth of the installation groove 12 is not less than the thickness of the flexible circuit board 3 to prevent the metal components of the needle tester from contacting the first section 31.

[0044] As Figures 1 to 5 shown, in some embodiments of the present invention, the installation groove 12 has a groove side wall 122 near the middle of the substrate 1, and the angle between the groove side wall 122 and the groove top wall 121 is an obtuse angle or a right angle, and another part of the first section 31 is attached to the groove side wall 122.

[0045] Specifically, the angle between the groove sidewall 122 and the groove top wall 121 is an obtuse angle or a right angle, so the groove sidewall 122 and the groove top wall 121 are relatively gentle. After another part of the first section 31 adheres to the groove sidewall 122, the entire first section 31 can remain relatively flat, and the bending of the first section 31 can be controlled within a small range, avoiding the problem of a sharp increase in the transient impedance.

[0046] In some embodiments, the angle between the groove sidewall 122 and the groove top wall 121 ranges from 120° to 160°, for example, it can be 140° or 150°, etc.

[0047] In some embodiments, the groove sidewall 122 and the groove top wall 121 are smoothly transitioned so that the first section 31 can be bent in a more gentle manner.

[0048] As Figures 1 to 4 shown, in some embodiments of the present invention, the outer peripheral portion of the substrate 1 is configured to be supported by the carrier 4 of the needle tester; and when the carrier 4 supports the outer peripheral portion of the substrate 1, there is a gap between the carrier 4 and the first section 31.

[0049] Specifically, the carrier 4 of the needle tester forms a support for the outer peripheral portion of the substrate 1, making the substrate 1 more stable. In addition, the carrier 4 and the first section 31 are spaced apart in the thickness direction of the flexible circuit board 3 (or in the thickness direction of the substrate 1, or in the depth direction of the mounting groove 12), and the carrier 4 and the first section 31 are spaced apart in the length direction L of the mounting groove 12. Since the carrier 4 is made of a metal material, spacing the carrier 4 and the first section 31 apart can prevent the carrier 4 from contacting or being too close to the first section 31, thereby avoiding interference with the electrical signals in the flexible circuit board 3.

[0050] As Figures 1 to 4 shown, in some embodiments of the present invention, an elastic member 5 is provided between the carrier 4 and the flexible circuit board 3. The elastic member 5 is located directly below the via conductive structure 11. The bottom surface of the elastic member 5 contacts the carrier 4, and the top surface of the elastic member 5 contacts the bottom surface of the first section 31.

[0051] Specifically, the elastic member 5 can apply an appropriate elastic force to the first section 31, so that there is a seamless conductive connection between the first section 31 and the external connection portion 112. Moreover, the elastic member 5 always isolates the carrier 4 and the flexible circuit board 3.

[0052] In some embodiments, the elastic member 5 can be a plastic spring or a rubber block, etc., and the present invention is not limited thereto.

[0053] In some embodiments, in the width direction W of the installation groove 12, the width of the carrier seat 4 can be greater than the width of the installation groove 12, so that the carrier seat 4 can span across the installation groove 12 in this width direction W; and the depth of the installation groove 12 is greater than or equal to the thickness of the flexible circuit board 3, so as to space apart the first section 31 from the carrier seat 4.

[0054] As Figures 3 to 4 shown, in some embodiments of the present invention, at least a part of the second section 32 is spaced apart from the bottom surface 14 of the substrate, so that the extending manner of the second section 32 is more adapted to the space between the bottom surface 14 of the substrate and the top end of the probe 2. And further, the second section 32 can be connected to the bottom of the substrate 1 through a plurality of fasteners.

[0055] In some embodiments, generally there is a height difference between the end of the probe 2 facing the substrate 1 and the bottom surface 14 of the substrate. The part of the second section 32 close to the probe 2 being spaced apart from the bottom surface 14 of the substrate can enable the extending manner of the second section 32 to adapt to the height difference between the bottom surface 14 of the substrate and the top end of the probe 2, so that the second section 32 can be kept as flat as possible.

[0056] In some other embodiments, the whole of the second section 32 is spaced apart from the bottom surface 14 of the substrate.

[0057] In still some other embodiments, the whole of the second section 32 is attached to the bottom surface 14 of the substrate, and the second section 32 and the bottom of the substrate 1 can be connected through a plurality of fasteners.

[0058] As Figures 1 to 4 shown, in some embodiments of the present invention, the via conductive structure 11 includes a via and a conductive component 111. The via extends along the thickness direction of the substrate 1, and the conductive component 111 is disposed in the via. A part of the conductive component 111 is exposed at the top wall 121 of the installation groove 12 to form an external connection part 112, and the conductive component 111 can be electrically connected to the testing device. Therefore, the probe 2 can be electrically connected to the conductive component 111 through the flexible circuit board 3 and the conductive component 111 in sequence.

[0059] As Figures 2 to 5 shown, in some embodiments of the present invention, the via conductive structure 11 includes a via and a conductive component 111. The via extends along the thickness direction of the substrate 1, the conductive component 111 is disposed in the via, and a part of the conductive component 111 is exposed at the top wall 121 of the installation groove 12 to form an external connection part 112, and the conductive component 111 can be electrically connected to the testing device. Therefore, the probe 2 can be electrically connected to the conductive component 111 through the flexible circuit board 3 and the conductive component 111 in sequence.

[0060] In some embodiments, the conductive component 111 can be electrically connected to the testing device through an electrical connection component such as a coaxial cable or a flexible circuit board, and the present invention does not make any limitations.

[0061] In some embodiments, as Figure 2 and Figure 3As shown, the via hole may exist in the form of a blind hole. For example, the via hole extends from the top surface 13 of the substrate to the top wall 121 of the mounting groove 12. In some embodiments, such as Figure 2 and Figure 3 shown, the via hole may exist in the form of a through hole. For example, the via hole extends from the top surface 13 of the substrate to its bottom surface, but the setting of the mounting groove 12 causes a part of the via hole to disappear. In some embodiments, such as Figure 4 shown, the via hole may also exist in the form of a buried hole.

[0062] In some embodiments, the conductive component 111 may be fixedly arranged in the via hole. For example, the conductive component 111 may be formed by electroplating in the via hole or may be clamped in the via hole.

[0063] In some embodiments of the present invention, the via hole is a circular hole, and the conductive component 111 is cylindrical.

[0064] Specifically, the conductive component 111 is set to be cylindrical, so that the outer surface of the conductive component 111 has as few sharp local structures such as edges and corners or protrusions as possible, thereby avoiding the problem of a sharp increase in the transient impedance of the conductive component 111 and ensuring the transmission stability of the conductive component 111.

[0065] In some embodiments of the present invention, the conductive component 111 includes a signal transmission part for transmitting signals and a grounding part for shielding external interference signals for the signal transmission part. The grounding part can protect the signal transmission part and prevent the signal transmission part from being interfered by external signals.

[0066] In some embodiments, the signal transmission part is cylindrical, and the grounding part surrounds and wraps the outer peripheral part of the signal transmission part, so that only the top surface electrically connected to the test device and the bottom surface electrically connected to the flexible circuit board 3 of the signal transmission part are exposed. And the grounding part has a uniform thickness.

[0067] Specific examples are used in this article to elaborate on the principles and implementation manners of the present invention. The description of the above examples is only used to help understand the method and its core idea of the present invention. The above are only the preferred implementation manners of the present invention. It should be noted that due to the limited nature of literal expression and objectively infinite specific structures, for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements, refinements or changes can be made, or the above technical features can be combined in an appropriate manner; these improvements, refinements, changes or combinations, or directly applying the concept and technical solution of the present invention to other occasions without improvement, should all be regarded as the protection scope of the present invention.

Claims

1. A test probe card, characterized in that, Comprising: A substrate (1), the substrate (1) having a substrate top surface (13) and a substrate bottom surface (14); a mounting groove (12) is provided at the bottom of the outer peripheral portion of the substrate (1), and the mounting groove (12) is recessed from the substrate bottom surface (14) towards the substrate top surface (13); a via conductive structure (11) for electrically connecting with a testing device is provided in the outer peripheral portion of the substrate (1), and the via conductive structure (11) has an outer connection portion (112) exposed at the top wall (121) of the mounting groove (12); and A probe (2), the probe (2) being fixedly mounted at the bottom of the substrate (1), the probe (2) being electrically connected to the outer connection portion (112) of the via conductive structure (11) through a flexible circuit board (3), and a part of the flexible circuit board (3) being fixedly mounted in the mounting groove (12).

2. The test probe card according to claim 1, wherein, The flexible circuit board (3) includes a first section (31) disposed in the mounting groove (12) and a second section (32) located outside the mounting groove (12), and a part of the first section (31) is attached to the top wall (121) of the mounting groove (12).

3. The test probe card according to claim 2, wherein The mounting groove (12) has a groove side wall (122) near the middle of the substrate (1), and the angle between the groove side wall (122) and the top wall (121) is an obtuse angle or a right angle, and another part of the first section (31) is attached to the groove side wall (122).

4. The test probe card according to claim 2, characterized in that, The outer peripheral portion of the substrate (1) is configured to be supported by a carrier (4) of a probing machine; and when the carrier (4) supports the outer peripheral portion of the substrate (1), there is a gap between the carrier (4) and the first section (31).

5. The test probe card according to claim 4, characterized in that, An elastic member (5) is provided between the carrier (4) and the flexible circuit board (3), the elastic member (5) is located directly below the via conductive structure (11), the bottom surface of the elastic member (5) contacts the carrier (4), and the top surface of the elastic member (5) contacts the bottom surface of the first section (31).

6. The test probe card according to claim 2, wherein At least a part of the second section (32) is spaced apart from the substrate bottom surface (14).

7. The test probe card according to claim 2, characterized in that, The top surface of the second section (32) is parallel to the substrate bottom surface (14).

8. The test probe card according to any one of claims 2-7, characterized in that, The via conductive structure (11) includes a via and a conductive component (111), the via extends along the thickness direction of the substrate (1), the conductive component (111) is disposed in the via, a part of the conductive component (111) is exposed at the top wall (121) of the mounting groove (12) to form the outer connection portion (112), and the conductive component (111) can be electrically connected to a testing device.

9. The test probe card according to claim 8, wherein The via is a circular hole, and the conductive component (111) is cylindrical.

10. The test probe card according to claim 8, characterized in that, The conductive component (111) includes a signal transmission part for transmitting signals and a grounding part for shielding external interference signals for the signal transmission part.

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