Cantilevered probe card with segmented structure
By introducing adjustable components into the cantilever probe card, the problem of non-independent probe height adjustment is solved, stable contact between the probe and the wafer pad is achieved, and the adaptability and reliability of the test are improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- MIXIN SEMICON (JIANGSU) CO LTD
- Filing Date
- 2025-08-29
- Publication Date
- 2026-08-04
AI Technical Summary
In existing technologies, cantilever probe cards cannot independently adjust the height of each probe, resulting in uneven contact force and affecting test adaptability and reliability.
Design a cantilever probe holder with a segmented structure, employing adjustable components including a pressure plate, a fixing frame, and a screw. The height of the probe's free end can be adjusted by horizontally moving the pressure plate and rotating the screw, achieving independent height adjustment.
Independent height adjustment of different regions of the probe array was achieved, improving test adaptability and reliability and ensuring stable contact between the probe and the wafer pad.
Smart Images
Figure CN224594712U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of probe cards, and in particular to a cantilever probe card with a segmented structure. Background Technology
[0002] Probe cards, also known as chip test cards, are tools used to test chip yield and are an indispensable part of the IC production chain. During wafer or chip testing, probes play a crucial role, accurately connecting the leads or solder balls of the wafer or chip to the testing equipment to detect performance indicators such as conductivity, current capability, functionality, and aging resistance. There are many types of probes, commonly including flexible probes, cantilever probes, and vertical probes.
[0003] Chinese patent disclosure (application number 202420173713.7) discloses a cantilever probe card with a segmented structure. The patent mainly includes a base plate and probes. A notch is formed at the center of the base plate, and a fixed block is fixedly connected inside the notch. A movable block is movably connected inside the fixed block, and epoxy resin is fixedly connected to the top of the movable block. The probes are arranged in multiple groups, with each group arranged in a linear array. While the patent improves the protection of the probes by incorporating a protective mechanism to reduce damage from probe bending and allow the probes to return to their original positions, the patent's design is not without merit.
[0004] However, the aforementioned patent mounts all probes onto epoxy resin. This monolithic epoxy resin support means that all probes can only move up and down as a whole during testing, making it impossible to independently adjust the height of each probe. When there are differences in the pad heights of the chips under test, especially when the difference in pad height between chips or different areas on the same chip exceeds the effective compression stroke of a single probe, the effective compression of the probes may be insufficient for chips with higher pads, while the probes may be over-compressed for chips with lower pads. This results in uneven probe contact force, affecting test adaptability and reliability. Utility Model Content
[0005] This invention provides a cantilever probe card with a segmented structure, which solves the problem in the prior art that cantilever probe cards with segmented structures cannot independently adjust the height of each probe, which easily leads to uneven probe contact force and affects the adaptability and reliability of testing.
[0006] A segmented cantilever probe card includes a PCB board, a needle ring disposed on the PCB board, and a plurality of probes evenly arranged on the needle ring. Each probe is a cantilever structure with elastic deformation capability. The free end of each probe extends toward the central axis of the needle ring, and an adjustment component is provided at each probe.
[0007] The adjustment assembly is used to adjust the height of the free end of the probe. The adjustment assembly includes a horizontally movable pressure plate. One end of the pressure plate is in contact with the probe. When the pressure plate moves horizontally, the pressure plate causes the probe to undergo longitudinal displacement through the contact position.
[0008] Preferably, the adjusting assembly further includes a fixed bracket mounted on the needle ring and a screw threadedly connected to the fixed bracket, one end of the screw being rotatably connected to the pressure plate, and the pressure plate being movably connected to the fixed bracket.
[0009] Preferably, the adjustment assembly further includes a retaining plate, which is inserted into the probe and fixedly connected to the pressure plate.
[0010] Preferably, a mounting plate is detachably connected to the needle ring, and the fixing bracket is fixed to the mounting plate.
[0011] Preferably, a bolt is inserted inside the mounting plate, the bolt is fixed to the pin ring, and a nut is threaded onto the bolt.
[0012] Preferably, a buffer pad is fixed on the side of the card plate near the probe, and the probe is slidably connected to the buffer pad.
[0013] Preferably, the probe has a bent portion at its free end.
[0014] Preferably, the adjustment assembly further includes a positioning groove formed on the fixed frame, and the pressure plate slides inside the positioning groove.
[0015] Preferably, the bottom of the buffer pad and the side closest to the probe are provided with a slope.
[0016] Preferably, the surface of the bent portion is provided with a metal plating layer.
[0017] This utility model provides a cantilever probe card with a segmented structure, which has the following advantages:
[0018] 1. Rotate the screw according to the height of the wafer pads, and the pressure plate moves horizontally. The contact point between the pressure plate and the probe applies pressure to the probe, causing it to elastically deform, thereby achieving fine adjustment of the height of the probe's free end. Each probe adjusts the height of its free end through the adjustment component. The adjustable structure of the probe allows for independent height adjustment of different areas of the probe array to better optimize the probe contact force for the wafer surface morphology, thereby improving test adaptability and reliability.
[0019] 2. The mounting plate is fixed with bolts and nuts. The adjustment component is mounted on the mounting plate. The mounting plate can be easily removed and installed to facilitate the disassembly and assembly of the adjustment component, and to facilitate the maintenance or replacement of the probe. Attached Figure Description
[0020] Figure 1A schematic diagram of the structure of a cantilever probe card with a segmented structure provided by this utility model. Figure 1 ;
[0021] Figure 2 A schematic diagram of the needle ring and probe structure of a cantilever probe card with a segmented structure provided by this utility model;
[0022] Figure 3 This utility model provides a cantilever probe card with a segmented structure. Figure 2 Enlarged structural diagram at point A in the middle;
[0023] Figure 4 This invention provides a schematic diagram of the adjustment component structure of a cantilever probe card with a segmented structure.
[0024] Explanation of reference numerals in the attached figures:
[0025] 1. PCB board; 2. Pin ring; 3. Probe; 4. Adjustment assembly; 401. Pressure plate; 402. Clamping plate; 403. Fixing bracket; 404. Screw; 405. Positioning groove; 5. Buffer pad; 6. Mounting plate; 7. Bolt; 8. Bevel; 9. Bending section. Detailed Implementation
[0026] The specific embodiments of this utility model are described in detail below, but it should be understood that the protection scope of this utility model is not limited to the specific embodiments.
[0027] like Figures 1 to 4 As shown in the figure, the present invention provides a cantilever probe card with a segmented structure, including a PCB board 1, a needle ring 2 disposed on the PCB board 1, and a plurality of probes 3 uniformly arranged on the needle ring 2. The needle ring 2 is used to fix the probes and maintain their arrangement accuracy. Each probe 3 is a cantilever structure with elastic deformation capability. The free end of each probe 3 extends towards the central axis of the needle ring 2. Each probe 3 is provided with an adjustment component 4. The adjustment component 4 is used to adjust the height of the free end of the probe 3. The adjustment component 4 includes a horizontally movable pressure plate 401, a fixing frame 403 mounted on the needle ring 2, and a screw 404 threadedly connected to the fixing frame 403. One end of the pressure plate 401 contacts the probe 3. When the pressure plate 401 moves horizontally, the pressure plate 401 causes the probe 3 to generate longitudinal displacement through the contact position. One end of the screw 404 is rotatably connected to the pressure plate 401. The pressure plate 401 is movably connected to the fixing frame 403.
[0028] The free end of probe 3 extends toward the central axis of probe ring 2 to accommodate the testing requirements of wafer pads. The adjustment component 4 on probe 3 is used to adjust the height of the free end of probe 3 to ensure stable contact with the wafer pads.
[0029] Rotate screw 404 according to the height of wafer pads, and pressure plate 401 moves horizontally. The contact point between pressure plate 401 and probe 3 applies pressure to probe 3, causing it to undergo elastic deformation, thereby achieving fine adjustment of the height of the free end of probe 3 to better adapt to the thickness differences in different areas on the wafer.
[0030] Wafer probe cards are designed to inspect the entire die on a chip by probing the solder pads on each die, thus separating good from defective dies. Each probe has a limited elastic compression stroke, allowing it to deform elastically upon contact with the solder pad to generate the necessary contact force. The probe stroke is limited. Traditional cantilever probe cards typically have probe arms supported by a rigid, monolithic substrate. All probes are mounted on this single, usually flat substrate, making it impossible to independently and precisely adjust the height of each probe. The entire probe card can only move up and down as a single unit during testing.
[0031] When the height difference between the pads of the tested chips or between different regions (such as the edge and the center) on the same chip exceeds the effective compression stroke of a single probe:
[0032] For chips with high pads, the effective compression of the probe may be insufficient (or even not at all), resulting in excessive contact resistance, unstable contact, or non-conductivity, causing test failure.
[0033] For chips with low pads, the probes may be overcompressed, far exceeding their designed travel, which may cause the probes to be damaged, bent, plastically deformed or even broken. Excessive contact force can also easily damage the pads.
[0034] The height of the free end of each probe 3 in this application can be adjusted by adjusting component 4. The adjustable structure of probe 3 allows for independent height adjustment of different regions of the probe array, so as to better optimize the contact force of probe 3 for wafer surface morphology and improve test adaptability and reliability.
[0035] In some specific implementation plans, such as Figure 3 and Figure 4 As shown, the adjustment assembly 4 also includes a retaining plate 402 and a positioning groove 405 formed on the fixing frame 403. The pressure plate 401 slides inside the positioning groove 405, which guides the sliding of the pressure plate 401. The retaining plate 402 has a U-shaped structure and is inserted into the probe 3. The retaining plate 402 is fixedly connected to the pressure plate 401. The head of the screw 404 is provided with an internal hexagonal groove.
[0036] The U-shaped clamp 402 is inserted into the probe 3. The side of the clamp 402 limits the probe 3, which helps to ensure the stability of the probe 3 when it deforms, so as to reduce the displacement of the probe 3 when pressure is applied to the contact point.
[0037] In some specific implementation plans, such as Figure 3 and Figure 4 As shown, a mounting plate 6 is detachably connected to the needle ring 2, and a fixing bracket 403 is fixed on the mounting plate 6. A bolt 7 is inserted inside the mounting plate 6, and the bolt 7 is fixed on the needle ring 2. A nut is threaded onto the bolt 7.
[0038] Mounting plate 6 is fixed by bolts 7 and nuts. Adjustment component 4 is installed on mounting plate 6. The mounting plate 6 can be easily disassembled and installed to facilitate the maintenance or replacement of probe 3.
[0039] In some specific implementation plans, such as Figure 3 and Figure 4 As shown, a buffer pad 5 is fixedly provided on the side of the clamping plate 402 near the probe 3 to protect the contact area between the probe 3 and the clamping plate 402 and reduce frictional damage between the probe 3 and the clamping plate 402. The probe 3 and the buffer pad 5 are slidably connected. The bottom of the buffer pad 5 and the side near the probe 3 are provided with inclined surfaces 8. The inclined surfaces 8 of the buffer pad 5 make it easy for the buffer pad 5 to slide with the probe 3 after being compressed when the clamping plate 402 is fitted onto the probe 3.
[0040] In some specific implementation plans, such as Figure 4 As shown, the probe 3 has a bent portion 9 at its free end, which contacts the wafer pad. The surface of the bent portion 9 is coated with a metal layer. Applying a metal-based protective coating to the surface of the bent portion 9 can improve the surface performance of the probe 3, such as common nickel plating and gold plating. Among them, nickel plating can improve wear resistance, while gold plating can optimize electrical performance.
[0041] To facilitate understanding of the embodiments of this solution by those skilled in the art, the working principle of this solution will now be briefly explained in conjunction with specific application scenarios:
[0042] The U-shaped clamp 402 is inserted into the probe 3. The side of the clamp 402 is used to limit the probe 3, which helps to ensure the stability of the probe 3 when it deforms, so as to reduce the displacement of the probe 3 when the contact point applies pressure to the probe 3.
[0043] Rotate screw 404 according to the height of wafer pads, and pressure plate 401 moves horizontally. The contact point between pressure plate 401 and probe 3 applies pressure to probe 3, causing it to undergo elastic deformation, thereby achieving fine adjustment of the height of the free end of probe 3 to better adapt to the thickness differences in different areas on the wafer.
[0044] Each probe 3 has its free end height adjusted by the adjustment component 4. The adjustable structure of the probe 3 allows for independent height adjustment of different areas of the probe array, so as to better optimize the contact force of the probe 3 for the wafer surface morphology and improve the test adaptability and reliability.
[0045] The above-disclosed embodiments are only a few specific examples of the present utility model. However, the embodiments of the present utility model are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the protection scope of the present utility model.
Claims
1. A cantilever probe card with a segmented structure, comprising a PCB board (1), a needle ring (2) arranged on the PCB board (1), and a plurality of probes (3) arranged uniformly on the needle ring (2), characterized in that, Each of the probes (3) is a cantilever structure with elastic deformation capability. The free end of each probe (3) extends toward the central axis of the needle ring (2). Each probe (3) is provided with an adjustment component (4). The adjustment component (4) is used to adjust the height of the free end of the probe (3). The adjustment component (4) includes a horizontally movable pressure plate (401). One end of the pressure plate (401) is in contact with the probe (3). When the pressure plate (401) moves horizontally, the pressure plate (401) causes the probe (3) to produce a longitudinal displacement through the contact position.
2. The cantilevered probe card having a segmented structure as recited in claim 1, wherein, The adjustment assembly (4) further includes a fixed frame (403) mounted on the pin ring (2) and a screw (404) threadedly connected to the fixed frame (403). One end of the screw (404) is rotatably connected to the pressure plate (401), and the pressure plate (401) is movably connected to the fixed frame (403).
3. The cantilevered probe card having a segmented structure as recited in claim 2, wherein, The adjustment component (4) also includes a retaining plate (402), which is inserted into the probe (3) and is fixedly connected to the pressure plate (401).
4. The cantilevered probe card having a segmented structure as recited in claim 2, wherein, The pin ring (2) is detachably connected to the mounting plate (6), and the fixing bracket (403) is fixed on the mounting plate (6).
5. The cantilevered probe card having a segmented structure as recited in claim 4, wherein, The mounting plate (6) has a bolt (7) inserted inside, the bolt (7) is fixed on the pin ring (2), and a nut is threaded onto the bolt (7).
6. The cantilevered probe card having a segmented structure as recited in claim 3, wherein, A buffer pad (5) is fixed on the side of the card plate (402) near the probe (3), and the probe (3) is slidably connected to the buffer pad (5).
7. The cantilevered probe card having a segmented structure as recited in claim 6, wherein, The probe (3) has a bent portion (9) at its free end.
8. The cantilevered probe card having a segmented structure as claimed in claim 7, wherein, The adjustment component (4) also includes a positioning groove (405) formed on the fixing frame (403), and the pressure plate (401) slides inside the positioning groove (405).
9. The cantilevered probe card having a segmented structure as claimed in claim 6, wherein, The bottom of the buffer pad (5) and the side near the probe (3) are provided with a slope (8).
10. A cantilever probe card with a segmented structure as described in claim 7, characterized in that, The surface of the bent portion (9) is provided with a metal plating layer.