Vacuum adsorption fixing device for micro chip bonding force test and test method

Abstract

The application belongs to the technical field of semiconductor micro-assembly and chip bonding strength test, and particularly relates to a vacuum adsorption fixing device for micro chip bonding force test and a test method. The device comprises a seat body, a groove body is arranged on the upper end surface of the seat body, a vacuum through hole is arranged on the lower end surface of the seat body, and the groove body is communicated with the vacuum through hole; a porous adsorption layer is arranged in the groove body; and a sealing plate is pressed on the upper end surface of the porous adsorption layer, an opening is arranged in the center of the sealing plate, and an anti-collision limiting ring is arranged around the opening.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor micro-assembly and chip bonding strength testing technology, specifically relating to a vacuum adsorption fixing device and testing method for testing the bonding force of microchips. Background Technology

[0002] In micro-assembly processes, bonding force tests are required before bonding microchips (size < 1mm × 1mm, thickness < 50μm). Existing bonding methods have several drawbacks, such as: 1. Mechanical clamping can easily cause stress concentration and breakage at the chip edges, especially for chips made of brittle materials, resulting in a high breakage rate; 2. Ordinary vacuum chucks have large apertures and uneven suction, which can cause microchips to be missed or warped, making it impossible to guarantee the flatness of the chip surface during testing, and directly affecting the accuracy of bonding force testing. 3. The flatness of the fixing device itself is poor, which makes it difficult to meet the stringent requirements of bonding force testing on the flatness of the chip surface, resulting in large deviations in test data; 4. Traditional solutions use colloid-assisted fixation, which can easily lead to residual glue or particulate contamination, and do not meet the requirements of high-cleanliness micro-assembly conditions.

[0003] In the existing technology, there is a lack of efficient vacuum adsorption fixation devices for testing the bonding force of microchips. Therefore, it is necessary to develop suitable vacuum adsorption fixation devices to solve the above problems. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a vacuum adsorption fixation device and testing method for testing the bonding force of microchips.

[0005] The technical solution provided by this invention is as follows: A vacuum adsorption fixation device for testing the bonding force of microchips includes: A base body, wherein a groove is provided on the upper end face of the base body and a vacuum through hole is provided on the lower end face of the base body, and the groove is connected to the vacuum through hole; A porous adsorption layer installed inside the tank; And a sealing plate pressed onto the upper surface of the porous adsorption layer, wherein the sealing plate has an opening at its center and an anti-collision limiting ring is provided around the opening in the circumferential direction.

[0006] Based on the above technical solution: The tiny chip has no edge stress, avoiding breakage caused by clamping; The adsorption surface between the porous adsorption layer and the microchip is flat throughout, ensuring that the chip is warped and guaranteeing the stability of the test benchmark. By using low vacuum voltage regulation control, a negative pressure area is formed within the anti-collision limiting ring, making the suction force controllable and uniform, thus avoiding damage to the chip due to excessive suction force. The chip remains undisplaced during the bonding force test, ensuring stable and reliable test data.

[0007] Preferably, the opening and the vacuum through-hole are vertically aligned. The opening can be a regular shape such as a circle or a square.

[0008] Specifically: The base is made of metal. The circumferential walls and bottom surface of the trough are flat and smooth.

[0009] Based on the above technical solution, the sealing between the tank and the porous adsorption layer can be ensured. Preferably, the flatness of the tank's peripheral wall and bottom surface is ≤3μm.

[0010] Specifically: The porous adsorption layer is made of microporous silicon carbide ceramic. The upper surface of the porous adsorption layer is lower than the upper surface of the base; The porous adsorption layer has a smooth and flat peripheral wall that fits into the peripheral wall of the tank. The bottom surface of the porous adsorption layer is flat and smooth, and it fits into the bottom surface of the tank.

[0011] Based on the above technical solution, microporous silicon carbide ceramics with pore sizes of 5–20 μm and pore spacing ≤0.3 mm can be obtained using existing technologies. These ceramics are adaptable to microchips, achieving full-coverage adsorption and ensuring uniform distribution of adsorption force. The smooth and flat peripheral and bottom surfaces of the porous adsorption layer ensure a tight seal between the porous adsorption layer and the corresponding peripheral and bottom surfaces of the base, thus enabling the porous adsorption layer to adhere to the substrate during operation. The multi-layered pressure-equalizing microchannels of the porous adsorption layer guarantee a pressure uniformity of ≥95% on the adsorption surface, ensuring consistent stress across all areas of the chip.

[0012] Specifically: The lower end surface of the sealing plate is flat and smooth, the upper end surface of the porous adsorption layer is flat and smooth, and the lower end surface of the sealing plate and the upper end surface of the porous adsorption layer are in contact. The thickness of the sealing plate is less than the thickness of the microchip.

[0013] Based on the above technical solution, most of the upper surface area of ​​the porous adsorption layer can be effectively sealed, thereby forming a strong negative pressure area within the anti-collision limiting ring area.

[0014] Specifically: The anti-collision limiting ring is made of polyetheretherketone or polyimide. The height of the anti-collision limiting ring is ≤50μm.

[0015] Based on the above technical solution, the anti-collision limiting ring is made of soft insulating material with a Shore hardness of D50–D60. It has both a certain degree of support and flexibility, and only serves to limit the chip without contacting the effective area of ​​the chip, thus avoiding collision damage to the chip edge.

[0016] Specifically: A vacuum module interface is provided at the bottom of the base.

[0017] Based on the above technical solution, the vacuum module can quickly break the vacuum after the test by using a vacuum fast on / off valve with a response time of ≤10ms, which facilitates stress-free chip removal and reduces the impact of the chip removal process on the chip.

[0018] This invention also provides a method for testing the bonding force of microchips, which uses the aforementioned vacuum adsorption fixation device for testing the bonding force of microchips. The testing method includes the following steps: 1) Place the microchip flat inside the opening; 2) Connect the vacuum voltage regulator to the vacuum through-hole; 3) Turn on the vacuum stabilizing device and adjust it to the preset vacuum level to adsorb the microchip on the upper surface of the porous adsorption layer; 4) Perform bonding force testing on the microchip.

[0019] Based on the above technical solution, the position of a microchip can be fixed without causing stress concentration or breakage at the chip edge due to mechanical clamping, and without causing any obstruction.

[0020] Specifically, in step 3), the vacuum degree is 0.02-0.05 MPa.

[0021] The aforementioned vacuum level can prevent damage to the chip from excessive suction or instability from insufficient suction.

[0022] Furthermore, step 5 is also included: after the test is completed, the vacuum regulator breaks the vacuum within 10ms.

[0023] Under the above conditions, the vacuum can be broken quickly.

[0024] Furthermore, before testing, the flatness of the upper surface of the porous adsorption layer is checked using an online flatness detection device to ensure that the flatness is ≤3μm.

[0025] Based on the above solution, the stability of the adsorption chip can be ensured.

[0026] The beneficial effects of this invention are as follows: 1. Shatterproof and reliable: The chip is fixed by low-stress adsorption on the back, with no edge clamping force. Combined with the over-adsorption protection mechanism, it fundamentally eliminates the problem of chip breakage caused by uneven force. 2. Precise testing: The ultra-flat base combined with the pressure equalization adsorption structure ensures that the chip does not warp after adsorption, the benchmark is stable during the bonding force test, and the data repeatability is high; 3. Adaptable to micro-chips: Micro-nano pore size material avoids leakage, and small pore spacing ensures uniform adsorption force. It can be compatible with extremely small chips with a size of <1mm×1mm and will not have chip embedding phenomenon. 4. Clean and easy to use: No adhesive is required for fixation, avoiding residual adhesive and particle contamination. The vacuum quick-connect and disconnect design improves the efficiency of picking up and placing wafers, and meets the requirements of high-cleanliness micro-assembly conditions. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the vacuum adsorption fixation device for testing the bonding force of microchips provided by the present invention.

[0028] Appendix Figure 1 The structures represented by each label are listed below: 1. Base; 2. Vacuum through hole; 3. Porous adsorption layer; 4. Sealing plate; 5. Opening; 6. Anti-collision limiting ring; 7. Vacuum module interface; 8. Microchip. Detailed Implementation

[0029] The principles and features of the present invention are described below. The embodiments given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0030] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0032] Example 1 like Figure 1As shown, a vacuum adsorption fixing device for testing the bonding force of a microchip includes a base 1, with a groove on the upper end face and a vacuum through-hole 2 on the lower end face, the groove communicating with the vacuum through-hole 2. It also includes a porous adsorption layer 3 installed within the groove, the upper end face of which is lower than the upper end face of the base 1. Furthermore, it includes a sealing plate 4 pressed against the upper end face of the porous adsorption layer 3, the sealing plate 4 having an opening 5 at its center, and an anti-collision limiting ring 6 circumferentially arranged around the opening 5. The thickness of the sealing plate 4 is less than the thickness of the microchip.

[0033] During testing, the aforementioned vacuum adsorption fixing device can use negative pressure to adsorb and fix the micro-chip onto the surface of the porous adsorption layer without creating obstructions, thus facilitating testing.

[0034] Example 2 Based on Example 1, the peripheral walls and bottom surface of the tank are flat and smooth. The peripheral walls of the porous adsorption layer 3 are flat and smooth, and are in contact with the peripheral walls of the tank; the bottom surface of the porous adsorption layer 3 is flat and smooth, and is in contact with the bottom surface of the tank. The lower end surface of the sealing plate 4 is flat and smooth, the upper end surface of the porous adsorption layer 3 is flat and smooth, and the lower end surface of the sealing plate 4 is in contact with the upper end surface of the porous adsorption layer 3.

[0035] The above technical solution can increase the tightness of the fit between components, improve the sealing effect of the contact surface, and prevent pressure leakage.

[0036] Example 3 The base 1 is made of metal. The porous adsorption layer 3 is made of microporous silicon carbide ceramic, which can be adapted to microchips to achieve full-coverage adsorption and ensure uniform distribution of adsorption force. The anti-collision limiting ring 6 is made of polyetheretherketone or polyimide.

[0037] All of the above materials can be obtained using existing technologies, which reduces the difficulty of manufacturing the equipment.

[0038] Example 4 A method for testing the bonding force of microchips includes the following steps: 1. Adsorption base: Made of metal with dimensions of 50mm×50mm×10mm, precision machined to ensure flatness ≤3μm, with a vacuum module interface on the bottom surface for connection to vacuum pipeline; 2. Porous adsorption layer of microporous silicon carbide ceramic: 0.5 mm thick, made of microporous silicon carbide ceramic material with 10 μm pore size and 0.2 mm pore spacing, uniformly composited on the upper surface of the adsorption substrate, with microchannels inside that can equalize pressure; 3. Vacuum pressure stabilizing device: Input air pressure range 0.4–0.6MPa, output vacuum degree can be continuously adjusted within the range of 0.02–0.05MPa, built-in pressure sensor realizes real-time feedback, and automatically starts over-suction protection when the pressure exceeds the set threshold; 4. Edge anti-collision positioning ring: made of PEEK material, Shore hardness D55, inner diameter matching the test area, height 30μm; 5. Vacuum quick-on / off valve: Response time ≤10ms, installed on the pipeline between the main vacuum interface and the vacuum pressure stabilizing module; 6. Workflow: - Place the microchip to be tested in the central region of the porous adsorption layer, with the edges limited by anti-collision positioning rings; - Turn on the vacuum regulator module and adjust it to the set vacuum level (select according to the chip size / thickness, such as 0.03MPa). The device will automatically regulate the voltage and adsorb the chip. - The bonding force testing equipment is used to calibrate the flatness of the porous adsorption layer through the online flatness detection interface before conducting the bonding force test; - After the test is completed, the vacuum is quickly turned on and off by controlling the vacuum valve to break the vacuum and remove the chip without stress.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A vacuum adsorption fixation device for testing the bonding force of microchips, characterized in that, include: A base (1) is provided with a groove on its upper end face and a vacuum through hole (2) on its lower end face, the groove being connected to the vacuum through hole (2). A porous adsorption layer (3) installed in the tank; And a sealing plate (4) pressed onto the upper surface of the porous adsorption layer (3), wherein the sealing plate (4) has an opening (5) at its center and an anti-collision limiting ring (6) is provided around the opening (5) in the circumferential direction.

2. The vacuum adsorption fixation device for testing the bonding force of microchips according to claim 1, characterized in that: The base (1) is made of metal; The circumferential walls and bottom surface of the trough are flat and smooth.

3. The vacuum adsorption fixation device for testing the bonding force of microchips according to claim 1, characterized in that: The porous adsorption layer (3) is made of microporous silicon carbide ceramic. The upper surface of the porous adsorption layer (3) is lower than the upper surface of the base (1); The peripheral walls of the porous adsorption layer (3) are flat and smooth, and fit into the peripheral walls of the tank. The bottom surface of the porous adsorption layer (3) is flat and smooth, and it fits into the bottom surface of the tank.

4. The vacuum adsorption fixation device for testing the bonding force of microchips according to claim 1, characterized in that: The lower end surface of the sealing plate (4) is flat and smooth, the upper end surface of the porous adsorption layer (3) is flat and smooth, and the lower end surface of the sealing plate (4) and the upper end surface of the porous adsorption layer (3) are in contact. The thickness of the sealing plate (4) is less than the thickness of the microchip (8).

5. The vacuum adsorption fixation device for testing the bonding force of microchips according to claim 1, characterized in that: The anti-collision limiting ring (6) is made of polyetheretherketone or polyimide; The height of the anti-collision limiting ring (6) is ≤50μm.

6. The vacuum adsorption fixation device for testing the bonding force of microchips according to any one of claims 1 to 5, characterized in that: The bottom of the base (1) is provided with a vacuum module interface (7).

7. A method for testing the bonding force of a microchip, characterized in that, The test is performed using the apparatus according to any one of claims 1 to 6, and the test method includes the following steps: 1) Place the microchip flat inside the opening (5); 2) Connect the vacuum stabilizing device to the vacuum through hole (2); 3) Turn on the vacuum stabilizing device and adjust it to the preset vacuum level to adsorb the microchip on the upper surface of the porous adsorption layer (3); 4) Perform bonding force testing on the microchip.

8. The method for testing the bonding force of microchips according to claim 7, characterized in that, In step 3): the preset vacuum level is 0.02-0.05 MPa.

9. The method for testing the bonding force of microchips according to claim 7, characterized in that, It also includes step 5): After the test is completed, the vacuum regulator breaks the vacuum within 10ms.

10. The method for testing the bonding force of microchips according to any one of claims 7 to 9, characterized in that: Before testing, the flatness of the upper surface of the porous adsorption layer (3) is checked with an online flatness detection device to ensure that the flatness is ≤3μm.

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