A test fixture for silicon substrates and bare dies

Abstract

The utility model relates to the technical field of semiconductor test, especially a test fixture for silicon substrate and bare chip, including base, movable lid is located the upper casing of base, and is located the compression mechanism on the upper casing, be equipped with test cavity on the base, the compression mechanism includes effort assembly and slow pressure subassembly, slow pressure subassembly lower part extends to the test cavity, slow pressure subassembly includes upper pressure plate and lower pressure plate, and upper pressure plate is movably arranged below the upper casing and is with effort assembly resistance, lower pressure plate is movably arranged below upper pressure plate, and at least one buffer layer is equipped between upper pressure plate and lower pressure plate, through multilayer flexible limiting and adjustable compression mechanism, realize the nondestructive test of chip, and compatible different thickness device.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor testing technology, specifically to a test fixture for silicon substrates and bare chips. Background Technology

[0002] Pre-tape fabrication functional testing is a crucial step in mitigating the losses associated with millions of tape-outs, requiring direct contact with the bare die pads for electrical performance verification. However, the silicon wafer thickness of bare dies is only 100-300μm, making them susceptible to breakage due to overload or uneven loading by traditional rigid clamping mechanisms. In the early stages of chip fabrication, the bare die surface lacks encapsulation protection, making it highly vulnerable to cracks or chipping due to mechanical stress. Existing test fixtures often employ rigid clamping blocks for direct pressing, making precise control of clamping force difficult and frequently resulting in chip damage or test signal distortion. Furthermore, the significant thickness variations among different chips mean that a single clamping stroke cannot meet adaptive requirements. Therefore, a test device that provides reliable electrical connections while avoiding overpressure is urgently needed. Utility Model Content

[0003] To address the shortcomings of existing technologies, the purpose of this invention is to provide a test fixture for silicon substrates and bare chips. Through multi-layer flexible limiting and adjustable clamping mechanisms, it enables non-destructive testing of chips and is compatible with devices of different thicknesses.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a test fixture for silicon substrates and bare chips, comprising a base, an upper housing movably covered by the base, and a clamping mechanism disposed on the upper housing. The base is provided with a test cavity, and the clamping mechanism includes a force-applying component and a pressure-relieving component. The lower part of the pressure-relieving component extends into the test cavity. The pressure-relieving component includes an upper pressure plate and a lower pressure plate. The upper pressure plate is movably disposed below the upper housing and abuts against the force-applying component. The lower pressure plate is movably disposed below the upper pressure plate, and at least one buffer layer is provided between the upper pressure plate and the lower pressure plate.

[0005] Preferably, the pressure relief assembly further includes a plurality of pin bolts; the upper pressure plate is slidably suspended below the upper housing via the pin bolts; and the lower pressure plate is floatingly suspended below the upper pressure plate via the pin bolts.

[0006] Preferably, the buffer layer is made of silicone.

[0007] Preferably, the force-applying component includes a tubular threaded copper column threaded to the upper housing and a steering wheel disk fixedly disposed on the top of the threaded copper column; the upper housing has an installation hole; the threaded copper column is coaxially disposed with the installation hole; the lower end of the threaded copper column abuts against the upper end of the upper pressure plate; and the steering wheel disk has an observation window.

[0008] Preferably, the upper pressure plate, the buffer layer, and the lower pressure plate are all provided with coaxial through holes, and the through holes correspond to the positions of the threaded copper pillar, the observation window, and the test chamber.

[0009] Preferably, the bottom surface of the lower pressure plate is coated with polytetrafluoroethylene.

[0010] Preferably, the fixture further includes a locking mechanism; the base includes a probe plate, a limiting plate, a fixing plate, and a lower housing; the limiting plate is inverted T-shape and fixed to the probe plate, with a test groove in the middle, the inner diameter of the test groove being larger than the inner diameter of the through hole; multiple probes are fixed to the probe plate, with their upper ends extending into the test groove and their lower ends extending downward out of the probe plate; the fixing plate presses the limiting plate and fixes the probe plate together with a positioning pin, and has a receiving groove in the middle corresponding to the test groove; the lower housing is a frame structure, with a through-cavity in the middle, and the lower housing is fixed to the fixing plate; the upper housing is covered by the locking mechanism on the lower housing.

[0011] Preferably, the locking mechanism includes a buckle, a connecting shaft, and a pin; the upper housing is hinged to the lower housing via the connecting shaft; the buckle is rotatably disposed at the right end of the upper housing via the pin; and the right end of the lower housing is provided with a latch that slides and engages with the buckle.

[0012] Preferably, the upper pressure plate is made of PPS material, and the lower pressure plate, probe plate and limiting plate are made of PEEK material.

[0013] Preferably, the bottom of the receiving groove is flush with the upper end surface of the limiting plate.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] The multi-layer flexible limiting structure enables pressure self-adaptation, is compatible with chips of different thicknesses, and the soft-hard-soft composite pressure plate significantly reduces the risk of chip breakage;

[0016] The observation window and through-hole design facilitate real-time visual inspection and infrared temperature measurement;

[0017] Modular design allows for quick replacement of probe boards and limit plates, adaptable to various packaging forms. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the longitudinal cross-section of the clamp of this utility model;

[0019] Figure 2 This is a schematic diagram of the overall structure of the clamp of this utility model;

[0020] Figure 3 This is a schematic diagram of the base structure of this utility model;

[0021] Figure 4 This is a schematic diagram of the pressure-relief component structure of this utility model;

[0022] Figure 5This is a schematic diagram of the structure of the pressure-relieving component of this utility model after the upper pressure plate is removed.

[0023] In the diagram: 1. Base, 11. Probe plate, 12. Limiting plate, 13. Fixing plate, 14. Lower housing, 15. Probe, 16. Positioning pin;

[0024] 2 Upper housing, 21 Mounting hole; 3 Clamping mechanism, 31 Steering wheel disc, 32 Threaded copper pillar, 33 Upper pressure plate, 34 Buffer layer, 35 Lower pressure plate, 36 Pin bolt, 37 Through hole;

[0025] 4. Buckle, 5. Connecting shaft, 6. Pin, 7. Device under test. Detailed Implementation

[0026] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings, so that those skilled in the art can more clearly understand how to practice this utility model. Although this utility model has been described in conjunction with its preferred embodiments, these embodiments are merely illustrative and not intended to limit the scope of this utility model.

[0027] See Figure 1-5 In one embodiment of this utility model, a test fixture for silicon substrates and bare chips includes: a base 1, an upper housing 2, a clamping mechanism 3 and a locking mechanism, the components working together to achieve flexible clamping and precise testing of the device under test 7.

[0028] The base 1 includes a probe plate 11, a limiting plate 12, a fixing plate 13, a lower housing 14, multiple probes 15, and four positioning pins 16. The probe plate 11 is the core support plate, and the multiple probes 15 are fixedly mounted on the probe plate 11. The fixing plate 13 is fixed to the probe plate 11 by the positioning pins 16 and bolts, and a receiving groove is formed in the middle of the fixing plate 13. The limiting plate 12 has an inverted T-shaped structure and is fixed to the probe plate 11 under the pressure of the fixing plate 13. A test groove is formed in the middle of the limiting plate 12 to accommodate the device under test 7. The bottom of the receiving groove is flush with the top of the limiting plate 12. The receiving groove and the test groove together form a T-shaped test cavity. The upper end of the probe 15 extends into the test groove to contact the device under test 7, and the lower end extends downward through the probe plate 11 to connect to external testing instruments.

[0029] The lower housing 14 has a frame structure with a through-cavity in the middle, which is covered by a fixing plate 13; a latch is provided at the right end of the lower housing 14.

[0030] The locking mechanism includes a buckle 4, a connecting shaft 5, and a pin 6; the upper housing 2 is hinged to the lower housing 14 via the connecting shaft 5, and the upper housing 2 can be flipped open and closed around the connecting shaft 5; the buckle 4 is rotatably located at the right end of the upper housing 2 via the pin 6; the buckle 4 slides and engages with the latch to lock the upper housing 2 and the lower housing 14; the upper housing 2 has a through mounting hole 21 in the center longitudinally.

[0031] The clamping mechanism 3 includes a force-applying component, a pressure-relieving component, and several pins and bolts 36; the force-applying component includes a steering wheel disk 31 and a threaded copper column 32, the steering wheel disk 31 being fixedly mounted on the top of the threaded copper column 32; the threaded copper column 32 is coaxially arranged with the mounting hole 21, and the threaded copper column 32 is threadedly connected to the upper housing 2; the threaded copper column 32 is a tubular structure, and an observation window coaxial with the threaded copper column 32 is provided on the steering wheel disk 31; during operation, the threaded copper column 32 can be rotated up and down by rotating the steering wheel disk 31.

[0032] The pressure-relief assembly comprises an upper pressure plate 33, a buffer layer 34, and a lower pressure plate 35 arranged sequentially from top to bottom. The upper pressure plate 33 is movably suspended on the upper housing 2 and below the threaded copper column 32 by a pin bolt 36. Supported by the pin bolt 36, the upper pressure plate 33 can float up and down relative to the upper housing 2 within a limited stroke. The buffer layer 34 and the lower pressure plate 35 are both movably suspended below the upper pressure plate 33 by the pin bolt 36. The buffer layer 34 is made of silicone and is used to absorb impact and distribute pressure evenly. The lower end of the lower pressure plate 35 is coated with polytetrafluoroethylene (PTFE) to reduce friction, prevent static electricity and chemical contamination, and ensure the purity of the test signal and the accuracy of the test results.

[0033] The upper pressure plate 33, buffer layer 34, and lower pressure plate 35 are all provided with coaxial through holes 37. The through holes 37 are aligned with the threaded copper pillar 32 and the observation window. This arrangement allows the test slot to remain open, facilitating observation and infrared temperature measurement of the device under test 7. The outer perimeter of the lower part of the pressure relief component is smaller than the lateral dimension of the test cavity, allowing the pressure relief component to extend into the test cavity after the upper housing 2 is closed. In addition, the inner diameter of the through hole 37 should be smaller than the inner diameter of the test slot. This design ensures that the polytetrafluoroethylene coating of the lower pressure plate 35 can completely cover the edge of the chip surface during the pressing process, avoiding contact failure due to interference at the edge of the through hole.

[0034] It should be noted that after the upper housing 2 is closed on the lower housing 14, the pressure relief assembly can pre-tighten the device under test 7 by its own weight under the action of the pin bolt 36, and then the threaded copper column 32 is pressed down to the upper pressure plate 33 by rotating the rudder wheel 31 to achieve the final flexible locking.

[0035] In other embodiments, the buffer layer 34 is not limited to the silicone material described above, but can also be other soft materials that are resistant to high temperatures and do not easily age, such as fluororubber sheets, to provide elastic cushioning and prevent chip damage.

[0036] The upper pressure plate 33 is made of PPS (polyphenylene sulfide), while the lower pressure plate 35, probe plate 11, and limiting plate 12 are all made of PEEK (polyether ether ketone), which combines strength and stability.

[0037] In summary, this device transforms traditional hard contact into soft contact through the multi-layered flexible structure of the pressure relief component (upper pressure plate - buffer layer - lower pressure plate). Combined with PTFE coating and precise probe positioning, it achieves zero-damage clamping during the chip fabrication and testing stage, ensuring signal testing accuracy and device safety.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A test fixture for silicon substrates and bare chips, comprising a base (1), an upper housing (2) movably covered by the base (1), and a clamping mechanism (3) disposed on the upper housing (2), wherein the base (1) is provided with a test cavity, characterized in that: The pressing mechanism (3) includes a force-applying component and a pressure-relieving component; the lower part of the pressure-relieving component extends into the test chamber; the pressure-relieving component includes an upper pressure plate (33) and a lower pressure plate (35), the upper pressure plate (33) is movably disposed below the upper housing (2) and abuts against the force-applying component; the lower pressure plate (35) is movably disposed below the upper pressure plate (33), and at least one buffer layer (34) is provided between the upper pressure plate (33) and the lower pressure plate (35).

2. The test fixture for silicon substrates and bare dies of claim 1, wherein: The pressure relief assembly also includes several pin bolts (36); the upper pressure plate (33) is slidably suspended below the upper housing (2) by the pin bolts (36); the lower pressure plate (35) is floatingly suspended below the upper pressure plate (33) by the pin bolts (36).

3. A test fixture for silicon substrates and bare chips according to claim 1, characterized in that: The buffer layer (34) is made of silicone.

4. A test fixture for silicon substrates and bare chips according to claim 1, characterized in that: The force-applying component includes a tubular threaded copper column (32) threadedly connected to the upper housing (2) and a steering wheel disk (31) fixedly disposed on the top of the threaded copper column (32); the upper housing (2) is provided with a mounting hole (21); the threaded copper column (32) is coaxially disposed with the mounting hole (21); the lower end of the threaded copper column (32) abuts against the upper end of the upper pressure plate (33); the steering wheel disk (31) is provided with an observation window.

5. A test fixture for silicon substrates and bare chips according to claim 4, characterized in that: The upper pressure plate (33), buffer layer (34) and lower pressure plate (35) are all provided with coaxial through holes (37), and the through holes (37) correspond to the positions of the threaded copper column (32), observation window and test cavity.

6. A test fixture for silicon substrates and bare chips according to claim 1, characterized in that: The bottom surface of the lower pressure plate (35) is coated with polytetrafluoroethylene.

7. A test fixture for silicon substrates and bare chips according to claim 5, characterized in that: The fixture also includes a locking mechanism; the base (1) includes a probe plate (11), a limiting plate (12), a fixing plate (13), and a lower housing (14); the limiting plate (12) is inverted T-shaped and fixed on the probe plate (11), with a test groove in the middle, the inner diameter of the test groove being larger than the inner diameter of the through hole (37); multiple probes (15) are fixed on the probe plate (11), the upper end extending into the test groove, and the lower end extending downward out of the probe plate (11); the fixing plate (13) presses the limiting plate (12) and fixes the probe plate (11) with a positioning pin (16), and a receiving groove corresponding to the test groove is opened in the middle; the lower housing (14) is a frame structure, with a through-cavity in the middle, and the lower housing (14) is fixed on the fixing plate (13); the upper housing (2) is covered on the lower housing (14) by the locking mechanism.

8. A test fixture for silicon substrates and bare chips according to claim 7, characterized in that: The locking mechanism includes a buckle (4), a connecting shaft (5), and a pin (6); the upper housing (2) is hinged to the lower housing (14) via the connecting shaft (5); the buckle (4) is rotatably disposed at the right end of the upper housing (2) via the pin (6); the right end of the lower housing (14) is provided with a latch that slides and engages with the buckle (4).

9. A test fixture for silicon substrates and bare chips according to claim 7, characterized in that: The upper pressure plate (33) is made of PPS material, and the lower pressure plate (35), probe plate (11) and limiting plate (12) are made of PEEK material.

10. A test fixture for silicon substrates and bare chips according to claim 7, characterized in that: The bottom of the receiving groove is flush with the upper surface of the limiting plate (12).

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