Thermal slip temporary bonding adhesive as well as preparation method and application thereof

Abstract

The invention provides a thermal slip temporary bonding adhesive and a preparation method and application thereof, and the thermal slip temporary bonding adhesive is prepared from the following raw materials in parts by weight: 50-70 parts of an organic solvent; 15 to 25 parts of basic resin; 10 to 21 parts of tackifying resin; 0.2 to 2 parts of an auxiliary agent; the basic resin comprises any one or a combination of at least two of a cycloolefin copolymer, a cycloolefin polymer and a cyclic block copolymer; the tackifying resin comprises low molecular weight polymer resin and other tackifying resin. The thermal slip temporary bonding adhesive provided by the invention has excellent chemical corrosion resistance and excellent bonding performance, is tightly combined with a wafer and a substrate, can well bond the wafer and the substrate together, and effectively prevents bonding pair defects; the temporary bonding adhesive is excellent in high temperature resistance, and can stably play a role without denaturation in the processing processes of wafer thinning and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of bonding adhesives, and relates to a heat-slip temporary bonding adhesive and a preparation method and application thereof, and specifically relates to a heat-slip temporary bonding adhesive with high adhesion and high chemical resistance and a preparation method and application thereof. Background Art

[0002] Currently, semiconductor wafer manufacturing is moving towards large size, multi-chip stacking and ultra-thinness to achieve high-performance system integration, multi-functions and low-cost benefits for high-end chips. The thickness of wafers in electronic components is getting thinner and thinner, and the thickness of a single wafer needs to be reduced to 100μm or even thinner, which makes ultra-thin wafers prone to warping and breakage during the packaging process. In order to improve the yield, processing accuracy and packaging accuracy of chip manufacturing, a supporting material is urgently needed to meet the demanding semiconductor packaging process. In this context, temporary bonding / debonding (TBDB) technology came into being.

[0003] Temporary bonding adhesive is the middle layer material that bonds the functional wafer and the temporary carrier together, and is also a key material in the wafer thinning process. From the perspective of temporary bonding adhesive materials, on the one hand, it is required to be able to tightly bond the wafer stack together so that the functional wafer is reliably supported and protected, and at the same time, it can withstand the processing conditions such as mechanical force, chemical corrosion and high temperature process in the subsequent process; on the other hand, it is required to be able to safely separate the functional wafer and the temporary carrier in a simple way after the processing is completed.

[0004] However, the existing temporary bonding adhesive has average bonding strength, and defects such as bubbles and peeling are prone to occur between the wafer and the temporary carrier after bonding; at the same time, the chemical resistance is insufficient, and it is easily corroded by chemical solutions during the wafer processing, resulting in a weakened supporting effect on the wafer.

[0005] Therefore, in the art, it is desired to develop a temporary bonding adhesive having high adhesion and high chemical resistance. Summary of the invention

[0006] In view of the deficiencies of the prior art, the purpose of the present invention is to provide a hot-slip temporary bonding adhesive and its preparation method and application, and specifically to provide a hot-slip temporary bonding adhesive with high adhesion and high chemical resistance and its preparation method and application. The present invention provides a temporary bonding adhesive with strong adhesion, strong chemical corrosion resistance and smooth film surface, which can temporarily fix the wafer on the support plate before thinning, cutting, grinding and other processes to support it to complete subsequent processing; it can be slid away from the support plate by heating, and can be easily cleaned using a cleaning agent (such as Samcien Remover3).

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a heat-slip temporary bonding adhesive, wherein the raw materials for preparing the heat-slip temporary bonding adhesive include the following components in parts by weight:

[0009]

[0010] The base resin includes any one of cycloolefin copolymer (COC), cycloolefin polymer (COP), cyclic block copolymer (CBC) or a combination of at least two thereof;

[0011] The tackifying resin includes low molecular weight polymer resin and other tackifying resins.

[0012] The present invention provides a temporary bonding adhesive having excellent bonding strength and chemical resistance by adding a specific base resin and a tackifying resin. The temporary bonding adhesive can be used to bond a temporary carrier and a wafer at a certain temperature and pressure. After the subsequent processing is completed, the working material can be slid by heating the temporary bonding adhesive and applying a certain force, and the working material can be easily peeled off from the support. At the same time, the remaining temporary bonding adhesive can be removed by an organic solvent, which greatly simplifies the processing process.

[0013] In the present invention, the amount of organic solvent in the raw materials for preparing the heat slip temporary bonding adhesive can be 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, 60 parts, 62 parts, 64 parts, 66 parts, 68 parts, 70 parts, etc.

[0014] In the present invention, in the raw materials for preparing the heat-slip temporary bonding adhesive, the amount of the base resin can be 15 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, 25 parts, etc.

[0015] In the present invention, in the raw materials for preparing the heat-slip temporary bonding adhesive, the amount of the tackifier resin can be 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, 21 parts, etc.

[0016] In the present invention, the amount of the auxiliary agent in the raw materials for preparing the heat slip temporary bonding adhesive can be 0.1 parts, 0.2 parts, 0.3 parts, 0.5 parts, 0.8 parts, 1 parts, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, etc.

[0017] Preferably, the weight average molecular weight (M) of the cycloolefin copolymer, cycloolefin polymer, or cyclic block copolymer is w) are each independently 20000-300000, for example, 20000, 40000, 60000, 80000, 100000, 120000, 140000, 150000, 160000, 180000, 200000, 220000, 240000, 260000, 280000, 300000, etc., preferably 40000-150000.

[0018] Preferably, the storage modulus of the cycloolefin copolymer, cycloolefin polymer, and cyclic block copolymer at 120°C is each independently 0.1 to 3.0 MPa, for example, 0.1 MPa, 0.3 MPa, 0.5 MPa, 0.8 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3.0 MPa, etc., and the storage modulus at 240°C is each independently 100 to 3000 Pa, for example, 100 Pa, 300 Pa, 500 Pa, 800 Pa, 1000 Pa, 1300 Pa, 1500 Pa, 1800 Pa, 2000 Pa, 2300 Pa, 2500 Pa, 2800 Pa, 3000 Pa, etc.

[0019] Preferably, the storage modulus of the cycloolefin copolymer, cycloolefin polymer and cyclic block copolymer at 120° C. is independently 0.1 to 1.5 MPa, and the storage modulus at 240° C. is independently 300 to 1500 Pa.

[0020] Preferably, the low molecular weight polymer resin comprises bicyclo[2,2,1]hept-2-ene-ethylene copolymer.

[0021] Preferably, the weight average molecular weight of the bicyclo[2,2,1]hept-2-ene-ethylene copolymer is 500-5000, for example, 500, 800, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, etc., preferably 2000-5000.

[0022] Preferably, the storage modulus of the bicyclo[2,2,1]hept-2-ene-ethylene copolymer at 120-180° C. is 3000 to 20000 Pa, for example, 3000 Pa, 5000 Pa, 8000 Pa, 10000 Pa, 12000 Pa, 14000 Pa, 16000 Pa, 18000 Pa, 20000 Pa, etc., preferably 4000 to 10000 Pa.

[0023] Preferably, the other tackifying resin comprises an aromatic petroleum resin.

[0024] Preferably, the organic solvent comprises any one of p-menthane, cyclopentane, cyclohexane, methylcyclohexane, and ethylcyclohexane, or a combination of at least two thereof, preferably p-menthane and / or ethylcyclohexane.

[0025] Preferably, the auxiliary agent comprises an antioxidant and / or an odor masking agent.

[0026] Preferably, the auxiliary agent includes 0.1-1 part (e.g., 0.1 part, 0.2 part, 0.3 part, 0.5 part, 0.8 part, 1 part, etc.) of antioxidant and 0.1-1 part (e.g., 0.1 part, 0.2 part, 0.3 part, 0.5 part, 0.8 part, 1 part, etc.) of odor masking agent.

[0027] Preferably, the antioxidant includes any one of a hindered phenol antioxidant, a phosphite antioxidant, and other antioxidants, or a combination of at least two thereof.

[0028] Preferably, the hindered phenol antioxidant includes antioxidant 1010 and / or antioxidant 1076.

[0029] Preferably, the phosphite antioxidant includes antioxidant 168 and / or antioxidant 626.

[0030] Preferably, the other antioxidants include any one of antioxidant 164, antioxidant TPP, and antioxidant DNP, or a combination of at least two of them.

[0031] Preferably, the antioxidant is antioxidant 1076 and / or antioxidant 1010.

[0032] Preferably, the odor masking agent includes any one of a solvent-based odor masking agent (such as KW-750), a composite deodorant (such as AD-ZW), and a fragrance-added odor masking agent (such as 8816, T-4009, T-2111) or a combination of at least two thereof, preferably a solvent-based odor masking agent and / or a composite deodorant.

[0033] In a second aspect, the present invention provides a method for preparing the hot slip temporary bonding adhesive as described in the first aspect, the preparation method comprising the following steps:

[0034] The organic solvent and the auxiliary agent are mixed and stirred, and then the base resin and the tackifying resin are added and stirred again to obtain the hot-slip temporary bonding adhesive.

[0035] As a preferred technical solution of the present invention, the preparation method comprises the following steps:

[0036] (1) adding an organic solvent to a stirred tank, starting stirring, and simultaneously starting a cooling water circulation system;

[0037] (2) adding an auxiliary agent to step (1) and stirring until a clear and transparent liquid is formed;

[0038] (3) adding the base resin and the tackifying resin to step (2), stirring until a clear and transparent liquid is formed, and filtering to obtain the hot slip temporary bonding adhesive.

[0039] Preferably, the temperature of the cooling water circulation system in step (1) is controlled at 25-30°C, for example, 25°C, 26°C, 28°C, 30°C, etc.

[0040] Preferably, the stirring rate in step (1) is 50-100 rpm, for example, 50 rpm, 60 rpm, 70 rpm, 80 rpm, 90 rpm, 100 rpm, etc.

[0041] Preferably, the temperature of step (2) is controlled at 25-30°C (e.g., 25°C, 26°C, 28°C, 30°C, etc.), the stirring rate is 50-100rpm (e.g., 50rpm, 60rpm, 70rpm, 80rpm, 90rpm, 100rpm, etc.), and the stirring time is 10-20min (e.g., 10min, 15min, 20min, etc.).

[0042] Preferably, the temperature of step (3) is controlled at 25-40°C (for example, 25°C, 30°C, 35°C, 40°C, etc.), the stirring rate is 50-70rpm (for example, 50rpm, 60rpm, 70rpm, etc.), and the stirring time is 15-30h (for example, 15h, 16h, 18h, 20h, 23h, 25h, 26h, 28h, 30h, etc.), preferably 20-25h.

[0043] Preferably, the accuracy grade of the filter element used for the filtration in step (3) is 0.1 to 10 μm, for example, 0.1 μm, 0.3 μm, 0.5 μm, 0.8 μm, 1 μm, 3 μm, 5 μm, 8 μm, 10 μm, etc., preferably 1 to 5 μm.

[0044] In a third aspect, the present invention provides an application of the heat-slip temporary bonding adhesive as described in the first aspect in a wafer processing technology.

[0045] Exemplarily, the method for applying the heat-slip temporary bonding adhesive in a wafer processing process comprises the following steps:

[0046] (a) Place a 4-inch wafer on a spin coater, start the vacuum system, fix the wafer with a suction cup, evenly pour 5-10 ml of the hot slip temporary bonding glue on the wafer, start spin coating, and set the spin coating rate to 1000-1500 rpm / 20-30 s;

[0047] (b) closing the vacuum chuck, removing the wafer coated with temporary bonding glue, placing it in an oven at 40 to 80° C. for 5 to 10 minutes, preferably taking it out after 5 minutes; then placing it in an oven at 120 to 160° C. for 5 to 10 minutes, preferably taking it out after 5 minutes;

[0048] (c) After baking, the wafer adhesive surface and the carrier protective layer are attached to the surface of the wafer stage, heated to 170-190°C, pressurized 1-10kN, bonded for 5-10 minutes (preferably 10 minutes), and cooled to room temperature to complete the temporary bonding of the wafer.

[0049] Compared with the prior art, the present invention has at least the following beneficial effects:

[0050] (1) The heat-slip temporary bonding adhesive provided by the present invention has excellent chemical corrosion resistance and excellent bonding performance. It is tightly bonded to the wafer and the substrate, and can well bond the wafer and the substrate together, effectively preventing defects in the bonding pair. The temporary bonding adhesive has excellent high temperature resistance and can remain unchanged during processing such as wafer thinning and function stably.

[0051] (2) The heat-slip temporary bonding adhesive provided by the present invention uses one or at least two of cycloolefin copolymers, cycloolefin polymers, cyclic block copolymers, low molecular weight polymer resins and other specific thickening resins. The three work together to ensure excellent basic performance while making the temporary bonding adhesive have low high-temperature rheological viscosity, which can achieve low-pressure bonding, and there will be no uneven force during the processing process. The film layer is uniform and the bonding warping is small. The use of other specific thickening resins makes the temporary bonding adhesive have excellent bonding properties and can provide stable bonding force.

[0052] (3) The heat-slip temporary bonding adhesive provided by the present invention has a high film hardness at room temperature and can provide sufficient supporting force to provide protection for processing such as wafer thinning. DETAILED DESCRIPTION

[0053] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0054] Unless otherwise specified, some raw material information involved in the following specific embodiments of the present invention is shown in Table 1 below. Other raw materials not shown are conventional materials in the art and can be purchased from commercial products.

[0055] Table 1

[0056]

[0057] Examples 1 to 4 and Comparative Examples 1 to 2

[0058] Examples 1 to 4 and Comparative Examples 1 to 2 respectively provide a heat-slip temporary bonding adhesive, and the raw materials and amounts thereof are shown in Table 2. In Table 2, the amount of each component is "kg".

[0059] Table 2

[0060]

[0061]

[0062] The preparation method of the hot-slip temporary bonding adhesive comprises the following steps:

[0063] (1) Adding an organic solvent to a stirred tank, starting stirring at a rate of 70 rpm, and simultaneously starting a cooling water circulation system, with the temperature controlled at 30° C.;

[0064] (2) adding an odor masking agent and / or an antioxidant to the mixture in step (1), and stirring at 30° C. and 70 rpm for 10 min until a clear liquid is formed;

[0065] (3) Add the base resin and tackifying resin to step (2), stir at 30°C and 70 rpm for 15 hours, and observe the temperature change in the kettle during this period. If the temperature rises too quickly, adjust the temperature of the circulating cooling water to control the temperature at 30°C. When the material in the kettle becomes clear and transparent, stop stirring and transfer to a filtration kettle for filtration to obtain the thermal slip temporary bonding adhesive.

[0066] The performance test of the hot-slip temporary bonding adhesive provided in the embodiment and the comparative example is carried out, and the test method is as follows:

[0067] (1) Film uniformity: A dried wafer coated with temporary bonding adhesive is prepared by the application method of temporary bonding adhesive in wafer processing technology. The thickness of the temporary bonding adhesive film on the wafer is measured using the nine-point method. The difference between the maximum film thickness and the minimum film thickness is taken as the film thickness TTV. The film thickness TTV is preferably less than 1 μm.

[0068] (2) Bonding strength: Take a rigid copper plate and a flexible copper sheet with a length of 10 cm and a width of 3 cm, apply temporary bonding glue on one end with an area of ​​15 mm × 30 mm, and stack the copper plate and the copper sheet together after curing into a film. Heat to 180°C, pressurize 1 kN, bond for 10 minutes, and measure the maximum tensile load using a universal testing machine after cooling. The ratio of the maximum tensile load to the bonding area is the bonding strength. The bonding strength is greater than 0.85 N / mm 2 is better;

[0069] (3) Bonding condition: Observe the center and edge of the bonding pair under a microscope. It is best if there are no defects such as edge collapse and snowflake-shaped bubbles.

[0070] (4) Bonding warpage: The test is conducted in accordance with the test method provided in GB / T 6620-2009 "Non-contact test method for silicon wafer warpage", and the test sample is a temporarily bonded wafer;

[0071] (5) Chemical resistance: The temporarily bonded wafers were immersed in 65% concentrated nitric acid at 60°C for 120 minutes, then taken out, rinsed with clean water, and dried. Visual inspection was conducted to see if there was any dissolution or whitening at the edges of the temporarily bonded wafers. If dissolution or whitening was found, it was corrosion visible to the naked eye. If no dissolution or whitening was found, it was no corrosion visible to the naked eye. In addition, the depth of corrosion at the edges of the temporarily bonded wafers was observed using a microscope.

[0072] (6) Debonding effect on cleaning: Soak the debonded wafer in a cleaning agent, ultrasonically clean it for 10 minutes, then take it out, rinse it, dry it, and observe the wafer surface under a microscope. It is best if there is no stain residue.

[0073] The performance test results are shown in Table 3.

[0074] Table 3

[0075]

[0076]

[0077] If the test result is excellent or the effect is good, it is evaluated as "○"; if the test result is defective or the effect is poor, it is evaluated as "×".

[0078] It can be seen from Table 3 that the hot slip temporary bonding adhesive prepared in Examples 1 to 4 of the present invention has uniform film thickness, reliable bonding, no bonding defects, good heat resistance, good chemical resistance, and can be cleaned with a cleaning agent without residual adhesive when used for wafer processing.

[0079] Compared with Example 4, the bonding strength and chemical resistance of the hot slip temporary bonding glue provided in Comparative Example 1 are significantly deteriorated, and the bonding warpage is significantly increased; the bonding condition and chemical resistance of the hot slip temporary bonding glue provided in Comparative Example 2 are significantly deteriorated, and the bonding warpage is significantly increased.

[0080] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the hot-slip temporary bonding adhesive and its preparation method and application, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A hot-slip temporary bonding adhesive, characterized in that: The raw materials for preparing the heat-slip temporary bonding adhesive include the following components in parts by weight: The base resin includes any one of cycloolefin copolymer, cycloolefin polymer, cyclic block copolymer or a combination of at least two thereof; The tackifying resin includes low molecular weight polymer resin and other tackifying resins.

2. The heat-slip temporary bonding adhesive according to claim 1, characterized in that: The weight average molecular weight of the cycloolefin copolymer, cycloolefin polymer, and cyclic block copolymer is independently 20,000 to 300,000, preferably 40,000 to 150,000; Preferably, the storage modulus of the cycloolefin copolymer, cycloolefin polymer, and cyclic block copolymer at 120° C. is independently 0.1 to 3.0 MPa, and the storage modulus at 240° C. is independently 100 to 3000 Pa; Preferably, the storage modulus of the cycloolefin copolymer, cycloolefin polymer and cyclic block copolymer at 120° C. is independently 0.1 to 1.5 MPa, and the storage modulus at 240° C. is independently 300 to 1500 Pa.

3. The heat-slip temporary bonding adhesive according to claim 1 or 2, characterized in that: The low molecular weight polymer resin includes a bicyclo[2,2,1]hept-2-ene-ethylene copolymer; Preferably, the weight average molecular weight of the bicyclo[2,2,1]hept-2-ene-ethylene copolymer is 500 to 5000, preferably 2000 to 5000; Preferably, the storage modulus of the bicyclo[2,2,1]hept-2-ene-ethylene copolymer at 120-180° C. is 3000 to 20000 Pa, preferably 4000 to 10000 Pa.

4. The hot-slip temporary bonding adhesive according to any one of claims 1 to 3, characterized in that: The other tackifying resins include aromatic petroleum resins.

5. The heat-slip temporary bonding adhesive according to any one of claims 1 to 4, characterized in that: The organic solvent includes any one of p-menthane, cyclopentane, cyclohexane, methylcyclohexane, and ethylcyclohexane, or a combination of at least two of them, preferably p-menthane and / or ethylcyclohexane.

6. The heat-slip temporary bonding adhesive according to any one of claims 1 to 5, characterized in that: The auxiliary agent includes an antioxidant and / or an odor masking agent; Preferably, the auxiliary agent includes 0.1 to 1 part of an antioxidant and 0.1 to 1 part of an odor masking agent.

7. The heat-slip temporary bonding adhesive according to claim 6, characterized in that: The antioxidant includes any one of hindered phenol antioxidants, phosphite antioxidants, and other antioxidants, or a combination of at least two thereof; Preferably, the hindered phenol antioxidant includes antioxidant 1010 and / or antioxidant 1076; Preferably, the phosphite antioxidant includes antioxidant 168 and / or antioxidant 626; Preferably, the other antioxidants include any one of antioxidant 164, antioxidant TPP, and antioxidant DNP, or a combination of at least two thereof; Preferably, the antioxidant is antioxidant 1076 and / or antioxidant 1010; Preferably, the odor masking agent comprises any one of a solvent-type odor masking agent, a composite deodorant, and a fragrance-type odor masking agent, or a combination of at least two thereof, preferably a solvent-type odor masking agent and / or a composite deodorant.

8. A method for preparing a heat-slip temporary bonding adhesive as claimed in any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: The organic solvent and the auxiliary agent are mixed and stirred, and then the base resin and the tackifying resin are added and stirred again to obtain the hot slip temporary bonding adhesive; Preferably, the preparation method comprises the following steps: (1) adding an organic solvent to a stirred tank, starting stirring, and simultaneously starting a cooling water circulation system; (2) adding an auxiliary agent to step (1) and stirring until a clear and transparent liquid is formed; (3) adding the base resin and the tackifying resin to step (2), stirring until a clear and transparent liquid is formed, and filtering to obtain the hot slip temporary bonding adhesive.

9. The preparation method according to claim 8, characterized in that: The temperature of the cooling water circulation system in step (1) is controlled at 25-30° C. Preferably, the stirring rate in step (1) is 50 to 100 rpm; Preferably, the temperature of step (2) is controlled at 25-30° C., the stirring rate is 50-100 rpm, and the stirring time is 10-20 min; Preferably, the temperature of step (3) is controlled at 25 to 40° C., the stirring rate is 50 to 70 rpm, and the stirring time is 15 to 30 h, preferably 20 to 25 h; Preferably, the filter element used in the filtration in step (3) has a precision grade of 0.1 to 10 μm, preferably 1 to 5 μm.

10. Use of the hot-slip temporary bonding adhesive according to any one of claims 1 to 7 in a wafer processing technology.

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