MEMS probe with small probe pressure and test structure thereof
By designing a combination of a hollowed-out MEMS probe and a support pad, the problem of excessive pressure on the test equipment by the probe card under high pin count and high current carrying capacity was solved, achieving a probe structure with stable contact and low pin pressure, which can meet the requirements of high pin count and high current.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-26
- Publication Date
- 2026-03-17
AI Technical Summary
Existing MEMS probe cards, under conditions of high pin count and high current carrying capacity, put excessive pressure on the testing equipment, leading to equipment damage or abnormal test results. Furthermore, the traditional method of increasing the probe diameter cannot effectively solve this problem.
A MEMS probe with low needle pressure is designed by combining a needle body with a hollow section structure and a support pad. The hollow section generates a small elastic force during bending deformation, thereby reducing needle pressure while ensuring the probe's current carrying capacity.
While reducing probe pressure, it ensures stable contact between the probe and the signal adapter and the chip under test, protects the equipment, adapts to high pin count and high current requirements, and avoids equipment damage and test abnormalities.
Smart Images
Figure CN121679080A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of test probes, specifically to a MEMS probe with low needle pressure and its test structure. Background Technology
[0002] The probe and its test head are the core components of a probe card. As a customized consumable, the probe card is mainly used in the CP testing stage before chip packaging, serving as an electrical signal channel connecting the chip and the test machine. MEMS probe cards have significant advantages over traditional probe cards. Currently, the development of MEMS probe cards in China started relatively late and is in its initial stage.
[0003] During the test, the probe tip contacts the chip, and the probe tail contacts the contact pad of the signal adapter. Under the action of the probe station, the chip under test moves closer to the test head, thereby squeezing the probe and deforming it. The deformed probe will exert a certain pressure on the signal adapter at the tail end and a certain pressure on the chip at the tip. The pressure at both ends can ensure stable contact between the tail end and the signal adapter, and between the tip and the chip under test, avoiding open circuits and ensuring stable resistance.
[0004] With the development of the chip industry, the probe card industry is currently moving towards higher pin counts and higher current carrying capacity. The traditional method to increase probe current carrying capacity is to increase the probe diameter. This method leads to an increase in the single-pin pressure of the probe. Simultaneously, high-pin-count probe cards result in a greater force exerted by the entire probe card on the testing equipment. The combined effect of these two factors leads to extremely high forces exerted by the probe card on the testing equipment. However, due to advancements in mechanical structures and materials science, the improvement in the testing equipment's ability to withstand these forces has become very slow. The inability of the testing equipment to keep up with the increased overall pressure from the probe card can cause equipment damage or abnormal test results. Summary of the Invention
[0005] To overcome the aforementioned problems, the present invention aims to provide a MEMS probe with low needle pressure and its testing structure. By reducing the needle pressure of a single needle, the pressure of the overall probe card on the testing equipment is reduced, and the current carrying capacity of the probe is not reduced while reducing the needle pressure.
[0006] To achieve the above objectives, the technical solution adopted by this invention is: a MEMS probe with low needle pressure, comprising a needle head, a needle body, and a needle tail.
[0007] The needle body includes a first needle body and a second needle body connected to each other, with the end of the first needle body connected to the needle tail and the end of the second needle body connected to the needle tip;
[0008] The second needle body has a hollowed-out section, forming a two-legged structure;
[0009] The bottom width of the end where the needle tail connects to the first needle body is greater than the width of the first needle body.
[0010] Preferably, the width and thickness of the first needle body and the second needle body are the same.
[0011] Preferably, the bottom width of the connection end between the needle tip and the second needle body is the same as the width of the first needle body.
[0012] Preferably, the hollowed-out portion is located in the middle of the vertical direction of the second needle body, and the hollowed-out portion is provided with a first hollowed-out end point and a second hollowed-out end point.
[0013] Preferably, the first hollowed-out end point is located near the first needle body end and is located at the center of the probe, the second hollowed-out end point is located near the needle tip end, and the second hollowed-out end point and the needle tip are spaced apart.
[0014] The present invention also provides a MEMS probe testing structure with low needle pressure, including a probe, and an upper cover plate, a middle cover plate and a lower cover plate arranged sequentially from top to bottom;
[0015] The upper cover plate is provided with a first pinhole adapted to the probe, the middle cover plate is provided with a third pinhole adapted to the probe, and the lower cover plate is provided with a fifth pinhole adapted to the probe.
[0016] A first support pad is provided between the upper cover plate and the middle cover plate, and a second support pad is provided between the middle cover plate and the lower cover plate;
[0017] The first support pad is provided with a second pinhole adapted to the probe, and the second support pad is provided with a fourth pinhole adapted to the probe;
[0018] The probe tip passes through the first, second, third, fourth, and fifth pin holes in sequence. The bottom width of the probe tail is greater than the diameter of the first pin hole, and the bottom surface of the probe tail contacts the top surface of the upper cover plate.
[0019] Preferably, the upper cover plate, middle cover plate, and lower cover plate are arranged in parallel to each other.
[0020] Preferably, the middle part of the first support pad and the second support pad is hollow.
[0021] Preferably, the height of the first support pad is smaller than the height of the second support pad.
[0022] Preferably, the upper cover plate and the middle cover plate move the same distance in the same direction within their respective planes. The probe is bent and deformed by the hole walls of the upper cover plate, the middle cover plate, and the lower cover plate, so that the part of the probe between the upper cover plate and the middle cover plate is in a vertical state, and the part between the middle cover plate and the lower cover plate is in a bent state. The bent part of the probe has two bending points, one at the top and one at the bottom.
[0023] The beneficial effects of this invention are: the second needle body of the probe deforms through the hollow part during the bending process, which reduces the overall elastic force generated, thereby protecting the contact point of the chip under test from stable contact with the needle tip and preventing it from being punctured by the needle tip. At the same time, it can also ensure stable contact between the needle tail and the contact point of the signal adapter. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of the probe structure in this embodiment;
[0025] Figure 2 This is a schematic diagram of the cover plate and support pad in the test structure of this embodiment;
[0026] Figure 3 This is a schematic diagram of the test structure in this embodiment;
[0027] Figure 4 This is a schematic diagram of the test head state of the test structure in this embodiment;
[0028] Figure 5 This is a schematic diagram of the test state of the test structure in this embodiment.
[0029] In the diagram: 1. Needle tip; 2. Needle body; 3. Needle tail; 4. First needle body; 5. Second needle body; 6. Cutout section; 7. First cutout end point; 8. Second cutout end point; 9. Upper cover plate; 10. First support pad; 11. Middle cover plate; 12. Second support pad; 13. Lower cover plate; 14. First pinhole; 15. Second pinhole; 16. Third pinhole; 17. Fourth pinhole; 18. Fifth pinhole; 19. Chip under test; 20. First contact point; 21. Signal adapter; 22. Second contact point. Detailed Implementation
[0030] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.
[0031] See Figure 1 As shown, this embodiment discloses a MEMS probe with low needle pressure, which includes a needle head 1, a needle body 2, and a needle tail 3 in sequence.
[0032] The needle body 2 includes a first needle body 4 and a second needle body 5 connected to each other. The end of the first needle body 4 is connected to the needle tail 3, and the end of the second needle body 5 is connected to the needle head 1.
[0033] The second needle body 5 is provided with a hollowed-out section 6;
[0034] The bottom width of the end where the needle tail 3 connects to the first needle body 4 is greater than the width of the first needle body 4.
[0035] The first needle body 4 and the second needle body 5 have the same width and thickness. The needle tail 3 has the same thickness as the first needle body 4. The bottom width of the end where the needle head 1 connects to the second needle body 5 has the same width as the first needle body 4.
[0036] The hollowed-out portion 6 is located in the middle of the vertical direction of the second needle body 5. The hollowed-out portion 6 is provided with a first hollowed-out end point 7 and a second hollowed-out end point 8. The first hollowed-out end point 7 is located near the end of the first needle body 4 and is located at the center of the probe. The second hollowed-out end point 8 is located near the end of the needle tip 1 and has a certain distance from the needle tip 1.
[0037] In one embodiment, the hollow part 6 forms a double-leg structure with a hollow center. The hollow area formed by the width and height of the hollow part 6 can be appropriately adjusted according to the actual needs of the probe needle pressure and current carrying capacity.
[0038] See Figures 2-5 As shown, this embodiment also discloses a MEMS probe test structure with small needle pressure, including the probe mentioned above, and also including an upper cover plate 9, a middle cover plate 11 and a lower cover plate 13 arranged in parallel from top to bottom;
[0039] The upper cover plate 9 is provided with a first pinhole 14 adapted to the probe, the middle cover plate 11 is provided with a third pinhole 16 adapted to the probe, and the lower cover plate 13 is provided with a fifth pinhole 18 adapted to the probe.
[0040] A first support pad 10 is provided between the upper cover plate 9 and the middle cover plate 11, and a second support pad 12 is provided between the middle cover plate 11 and the lower cover plate 13.
[0041] The first support pad 10 is provided with a second pinhole 15 adapted to the probe, and the second support pad 12 is provided with a fourth pinhole 17 adapted to the probe.
[0042] The probe tip 1 passes through the first pinhole 14, the second pinhole 15, the third pinhole 16, the fourth pinhole 17, and the fifth pinhole 18 in sequence. The bottom width of the needle tail 3 is larger than the diameter of the first pinhole 14 to prevent the needle tail 3 from falling into the first pinhole 14. The bottom surface of the needle tail 3 is in contact with the top surface of the upper cover plate 9.
[0043] The first support pad 10 and the second support pad 12 are hollow in the middle. The first support pad 10 and the second support pad 12 are thin-walled U-shaped structures, which do not affect the probe passing through the middle cover 11 and the lower cover 13 from the upper cover 9. The height of the first support pad 10 is smaller than the height of the second support pad 12. The upper surface of the first support pad 10 is in contact with the lower surface of the upper cover 9, the lower surface of the first support pad 10 is in contact with the upper surface of the middle cover 11, the upper surface of the second support pad 12 is in contact with the lower surface of the middle cover 11, and the lower surface of the second support pad 12 is in contact with the upper surface of the lower cover 13.
[0044] In use, first arrange the upper cover plate 9, the first support pad 10, the middle cover plate 11, the second support pad 12, and the lower cover plate 13 in sequence, so that the first pinhole 14, the second pinhole 15, the third pinhole 16, the fourth pinhole 17, and the fifth pinhole 18 are in a straight line. Insert the probe tip 1 from the first pinhole 14 on the upper cover plate 9 downwards until it passes through the lower cover plate 13, so that the bottom surface of the needle tail 3 contacts the top surface of the upper cover plate 9. Then, apply external force to the upper cover plate 9 and the middle cover plate 11 in their respective planes in the same direction. The probe moves the same distance in the same direction, while the lower cover plate 13 remains stationary. The probe is bent and deformed by the hole walls of the upper cover plate 9, the middle cover plate 11, and the lower cover plate 13. The part of the probe between the upper cover plate 9 and the middle cover plate 11 is in a vertical state, while the part between the middle cover plate 11 and the lower cover plate 13 is in a bent state. The bent part of the probe has two bending points, forming a test head. That is, the needle head 1 protrudes a certain length from the lower surface of the lower cover plate 13, and the needle tail 3 protrudes a certain length from the upper surface of the upper cover plate 9.
[0045] During the test, the chip under test (DUT) 19 moves closer to the test head (i.e., the probe moves from the tip 1 to the tail 3). The first contact point 20 of the DUT 19 contacts the tip 1. As the DUT 19 moves towards the test head, the tip 1 is compressed and moves upward, causing the tail 3 to move upward as well. The tail 3 contacts the second contact point 22 of the signal adapter 21 at its top. As the DUT 19 continues to move towards the test head, the probe is compressed, and the second needle body 5 begins to bend and deform. The elastic force generated by the deformation ensures stable contact between the tail 3 and the second contact point 22 of the signal adapter 21, and also ensures stable contact between the tip 1 and the first contact point 20 of the DUT 19. During this process, because the second needle body 5 has a hollow portion 6, the elastic force generated during bending and deformation is relatively small. Therefore, the pressure exerted by the tip 1 on the DUT 19 is relatively small.
[0046] Because the contact force between the needle tail 3 and the second contact point 22 of the signal adapter 21 is relatively small, this test structure can accommodate a larger number of probes on the test head when the pressure that the test system can withstand is constant.
[0047] The external force can be manual or mechanical, such as a cylinder or push rod. This embodiment does not impose any limitations.
[0048] In one embodiment, the needle 1 is V-shaped in the width direction, which facilitates the needle 1 to pass through the corresponding needle holes of the upper cover plate 9, the middle cover plate 11 and the lower cover plate 13 during the probe insertion process; the needle tail 3 is short in length, which can ensure that less part of the needle tail 3 is left on the upper surface of the upper cover plate 9.
[0049] In one embodiment, the positions of the first hollow end point 7 and the second hollow end point 8 can be set slightly above or slightly below the center in the probe length direction. The positions of the first hollow end point 7 and the second hollow end point 8 can be changed according to the bending characteristics of different materials to ensure that the position of the bent part of the probe basically coincides with the position of the hollow part 6.
[0050] In one embodiment, given the thickness of the first support pad 10, when the total length of the probe changes, the length of the needle 1 exposed on the lower surface of the lower cover plate 13 can be controlled by adjusting the thickness of the second support pad 12.
[0051] In one embodiment, the position of the first pinhole 14 on the upper cover plate 9 and the position of the third pinhole 16 on the middle cover plate 11 are in the same vertical direction, while the position of the fifth pinhole 18 on the lower cover plate 3 is not on the same straight line as the first pinhole 14 and the third pinhole 16, and can be offset by a specific distance in a specific direction.
[0052] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.
Claims
1. A MEMS probe with a small needle pressure, comprising a needle head, a needle body and a needle tail in sequence, characterized in that: the needle body comprises a first needle body and a second needle body connected to each other, an end of the first needle body is connected to the needle tail, and an end of the second needle body is connected to the needle head; the second needle body is provided with a hollow part; a bottom surface width dimension of the needle tail at a connecting end of the first needle body is greater than a width dimension of the first needle body. The width dimension and thickness dimension of the first needle body and the second needle body are the same. The bottom surface width dimension of the needle head at a connecting end of the second needle body is the same as the width dimension of the first needle body. The hollow part is arranged at a middle part in a vertical direction of the second needle body, and the hollow part is provided with a first hollow end point and a second hollow end point.
2. The low-force MEMS probe according to claim 1, wherein The first hollow end point is located close to the end of the first needle body, and the first hollow end point is located at a central position of the probe, the second hollow end point is located close to the end of the needle head, and the second hollow end point has a spacing from the needle head.
3. The low-force MEMS probe of claim 1, wherein The probe according to any one of claims 1-5, further comprising an upper cover plate, a middle cover plate and a lower cover plate arranged in sequence from top to bottom.
4. The low-force MEMS probe of claim 1, wherein The upper cover plate is provided with a first needle hole matched with the probe, the middle cover plate is provided with a third needle hole matched with the probe, and the lower cover plate is provided with a fifth needle hole matched with the probe.
5. The low-force MEMS probe of claim 4, wherein A first supporting pad plate is arranged between the upper cover plate and the middle cover plate, and a second supporting pad plate is arranged between the middle cover plate and the lower cover plate.
6. A MEMS probe test structure with low needle force, characterized in that, The first supporting pad plate is provided with a second needle hole matched with the probe, and the second supporting pad plate is provided with a fourth needle hole matched with the probe. The needle head of the probe sequentially passes through the first needle hole, the second needle hole, the third needle hole, the fourth needle hole and the fifth needle hole, and a bottom surface width dimension of the needle tail is greater than a hole diameter dimension of the first needle hole, and the bottom surface of the needle tail is in contact with a top surface of the upper cover plate. The upper cover plate, the middle cover plate and the lower cover plate are arranged in parallel with each other. The middle parts of the first supporting pad plate and the second supporting pad plate are hollow. A height dimension of the first supporting pad plate is smaller than a height dimension of the second supporting pad plate.
7. The low-profile MEMS probe test structure of claim 6, wherein, The upper cover plate and the middle cover plate move in the same direction by the same distance in their respective planes, the probe is bent and deformed by a hole wall of the upper cover plate, a hole wall of the middle cover plate and a hole wall of the lower cover plate, a part of the probe between the upper cover plate and the middle cover plate is in a vertical state, a part of the probe between the middle cover plate and the lower cover plate is in a bent state, and the bent part of the probe has two bending points in a top-bottom direction.
8. The low-profile MEMS probe test structure of claim 6, wherein, 9. The low-profile MEMS probe test structure of claim 6, wherein, 10. The low-profile MEMS probe test structure of claim 6, wherein,