CN115247032A - A kind of high-efficiency grinding tape for wafer thinning and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of C09J grinding adhesive tapes, and particularly provides a high-efficiency grinding adhesive tape for wafer thinning and a preparation method thereof. The multifunctional adhesive prepared by using vinyl acetate, N-hydroxymethyl acrylamide, glycidyl methacrylate, benzoyl peroxide, styrene-butadiene-styrene block copolymer, nitrile rubber, triethanolamine, hexamethylenetetramine and the like as raw materials has no bubbles in the coating process, has uniform adhesive layer thickness, has excellent wear resistance, compressive strength, tensile strength and peeling strength compared with the prior art, and has potential application prospect in the field of semiconductor processing.

Description

High-efficiency grinding tape for wafer thinning and preparation method thereof

technical field

The invention relates to the technical field of C09J grinding tape, more specifically, the invention provides a high-efficiency grinding tape for wafer thinning and a preparation method thereof.

Background technique

With the rapid development of electronic technology, semiconductor materials are widely used in the fields of integrated circuits, communication systems, and power conversion. The comprehensive performance of semiconductor materials directly affects the use of integrated circuits and communication systems. In order to further improve the comprehensive performance of semiconductor materials, wafer thinning processing is usually performed on semiconductor chips. Grinding tape is a commonly used tool in the process of wafer thinning. How to enhance the bonding performance and wear resistance of grinding tape has become one of the focus of research workers.

The Chinese invention patent with the patent publication number CN108587502A discloses a semiconductor wafer processing adhesive tape and its preparation method. The adhesive tape prepared in the disclosed patent has excellent moisture tolerance, adhesion and durability, but when its solution When the thickness of the middle adhesive is 150 microns, there may be problems of air bubbles and poor uniformity of the thickness of the adhesive layer during the coating process, which will affect the effect of the adhesive tape in the semiconductor processing process.

Therefore, developing a grinding tape that is not prone to air bubbles during the preparation process and has excellent uniformity in the thickness of the adhesive layer has potential application value in the field of wafer thinning processing.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, the first aspect of the present invention provides a high-efficiency abrasive tape for wafer thinning, the preparation raw materials include an elastic resin matrix, a multifunctional adhesive and abrasive grains.

As a preferred technical solution of the present invention, the elastic resin matrix includes at least one of polyethylene elastomer, polyurethane elastomer, polystyrene elastomer, polyamide elastomer, and polypropylene elastomer.

As a more preferred technical solution of the present invention, the elastic resin matrix is polyurethane elastomer.

As a preferred technical solution of the present invention, the raw materials for the preparation of the multifunctional adhesive include the following components in parts by weight: 60-100 parts of acrylate compounds, 1-5 parts of initiator, toughness improver 5-15 parts, 1-3 parts of organic amine compound, 3-10 parts of viscosity modifier, 1-3 parts of accelerator, 1-3 parts of silane coupling agent, and 1-3 parts of functional auxiliary agent.

As a preferred technical solution of the present invention, the acrylate compounds include butyl acrylate, isooctyl acrylate, methyl methacrylate, vinyl acetate, N-methylol acrylamide, glycidyl methacrylate , at least one of hydroxyethyl methacrylate and the like.

As a more preferred technical solution of the present invention, the acrylate compound is vinyl acetate, N-methylolacrylamide, glycidyl methacrylate, vinyl acetate, N-methylolacrylamide, formaldehyde The weight ratio of glycidyl acrylate is (0.5-1.5): (0.2-0.8): (0.6-1.2).

As a most preferred technical solution of the present invention, the weight ratio of vinyl acetate, N-methylol acrylamide, and glycidyl methacrylate is 1:0.4:0.8.

As a preferred technical solution of the present invention, the initiator includes at least one of organic peroxide initiators, inorganic peroxide initiators, azo initiators and the like.

As a more preferred technical solution of the present invention, the initiator is an organic peroxide initiator.

As a preferred technical scheme of the present invention, the organic peroxide initiators include benzoyl peroxide, lauroyl peroxide, cumene hydroperoxide, tert-butyl peroxybenzoate, dicarbonic acid peroxide at least one of diisopropyl esters.

As a more preferred technical solution of the present invention, the organic peroxide initiator is benzoyl peroxide.

As a preferred technical solution of the present invention, the toughness improver includes nitrile rubber, isobutylene rubber, styrene-butadiene-styrene block copolymer, methyl methacrylate-butadiene-styrene three At least one of meta-copolymer, oxidized polyethylene, etc.

As a kind of more preferred technical scheme of the present invention, described toughness improver is styrene-butadiene-styrene block copolymer, nitrile rubber, the weight ratio of styrene-butadiene copolymer, nitrile rubber is (0.4-1.2): (1-1.5).

As a most preferred technical solution of the present invention, the weight ratio of the styrene-butadiene-styrene block copolymer to nitrile rubber is 0.6:1.2.

As a preferred technical solution of the present invention, the molar content of styrene in the styrene-butadiene-styrene block copolymer is 25-35%.

As a more preferred technical solution of the present invention, the molar content of styrene in the styrene-butadiene-styrene block copolymer is 30%.

As a preferred technical solution of the present invention, the nitrile rubber is semi-crosslinked powdered nitrile rubber.

As a preferred technical solution of the present invention, the molar content of bound acrylonitrile in the semi-crosslinked powdered nitrile rubber is 30-35%.

As a more preferred technical solution of the present invention, the molar content of bound acrylonitrile in the semi-crosslinked powdered nitrile rubber is 33%.

As a preferred technical solution of the present invention, the organic amine compound includes at least one of diethanolamine, triethanolamine, and hexamethylenetetramine.

As a more preferred technical solution of the present invention, the organic amine compound is triethanolamine and hexamethylenetetramine, and the weight ratio of triethanolamine and hexamethylenetetramine is (0.2-0.4): (0.7- 1.3).

As a most preferred technical solution of the present invention, the weight ratio of triethanolamine and hexamethylenetetramine is 0.3:1.1.

As a preferred technical solution of the present invention, the viscosity modifier includes at least one of terpene resin, petroleum resin, polystyrene, phenolic resin and the like.

As a more preferred technical solution of the present invention, the viscosity modifier is phenolic resin and polystyrene, and the weight ratio of phenolic resin and polystyrene is (1-1.7):(0.3-0.7).

As a most preferred technical solution of the present invention, the weight ratio of the phenolic resin to polystyrene is 1.5:0.5.

As a preferred technical solution of the present invention, the molar content of methylol in the phenolic resin is 8-10%.

As a more preferred technical solution of the present invention, the molar content of methylol in the phenolic resin is 9.8%.

As a preferred technical solution of the present invention, the melt flow rate of the polystyrene at 230° C. is 4-10 g/10 min.

As a more preferred technical solution of the present invention, the melt flow rate of the polystyrene at 230° C. is 7.2 g/10 min.

As a preferred technical solution of the present invention, the accelerator includes at least one of thiourea, hydroquinone, p-hydroxyanisole, N,N-dimethyl-p-phenylenediamine, and tetramethylthiourea. kind.

As a preferred technical solution of the present invention, the silane coupling agent includes at least one of KH550, KH560, KH570, KH580, KH590, KH902, and KH792.

As a preferred technical solution of the present invention, the functional auxiliary agent includes at least one of wetting agent, defoamer and leveling agent.

As a more preferred technical solution of the present invention, the functional auxiliary is a wetting agent.

As a preferred technical solution of the present invention, the wetting agent is a silicone wetting agent.

As a preferred technical solution of the present invention, the abrasive particles are inorganic oxides with a particle size of 14-18 μm, and the added amount is 10-30% of the weight of the multifunctional adhesive.

As a more preferred technical solution of the present invention, the inorganic oxide includes at least one of Al ₂ O ₃ , Cr ₂ O ₃ , Fe ₂ O ₃ , ZrO ₂ , CaO, and SiO ₂ .

The second aspect of the present invention provides a method for preparing a high-efficiency grinding tape for wafer thinning, comprising the following steps;

(1) Stir acrylate compounds, toughness modifiers, organic amine compounds, viscosity modifiers, accelerators, silane coupling agents, and functional additives at 60-90°C to obtain a mixture;

(2) After uniformly coating the mixture described in step (1) on the surface of the substrate, then uniformly coating the abrasive grains on the surface of the mixture, adding an initiator, and baking at 70-80°C for 0.5-2h to obtain the obtained High-efficiency grinding tape for wafer thinning.

Wherein, the thickness of the substrate in step (2) is 20-30 μm.

The thickness of the dry glue in the grinding tape described in step (2) is 20-150 μm.

Compared with the prior art, the present invention has the following beneficial effects:

1. The high-efficiency grinding tape for wafer thinning prepared by the present invention adopts a reasonable compound of vinyl acetate, N-methylol acrylamide, and glycidyl methacrylate. When the weight ratio of ester, N-methylolacrylamide, and glycidyl methacrylate is 1:0.4:0.8, it interacts with other components in the system, and has excellent wettability and cohesiveness. The prepared On the one hand, the abrasive tape can have a good coating effect with the polyurethane elastomer matrix in this system, and on the other hand, it has a good affinity with the abrasive silica particles in this system, and it can be applied to wafer thinning During the processing process, the internal stress of the chip, package volume, heat dissipation efficiency, etc. have been significantly improved, and the service life and application range of the chip have been expanded.

2. The high-efficiency grinding tape for wafer thinning prepared by the present invention is compounded reasonably by styrene-butadiene-styrene block copolymer, nitrile rubber, especially when styrene-butadiene-styrene The weight ratio of block copolymer and nitrile rubber is 0.6:1.2, and the molar content of styrene in the styrene-butadiene-styrene block copolymer is 30%, and the nitrile rubber is that the combined acrylonitrile molar content is 33% semi-crosslinked powdered nitrile rubber, on the basis of improving the load-bearing strength and fatigue resistance of the multifunctional adhesive, it can effectively avoid the multifunctional adhesive through synergistic effects with the phenolic resin and other components in the component. Air bubbles are easy to appear during the coating process, and no air bubbles will appear when the thickness of the dry glue is 150 μm. The prepared grinding tape has excellent comprehensive performance and will not contaminate chips during semiconductor processing.

3. The high-efficiency grinding tape for wafer thinning prepared by the present invention is reasonably processed by introducing polystyrene with a molar content of 9.8% of methylol groups and a melt flow rate of 7.2g/10min at 230°C into the system. Compounding, especially when the weight ratio of phenolic resin and polystyrene is 1.5:0.5, on the one hand, it promotes the full and uniform dispersion of each component in the system and improves the stability of the system; on the other hand, it can improve the internal The structure enhances the bonding performance, compression resistance, wear resistance, tensile strength and peel strength of the multi-functional adhesive, effectively avoiding the problem that the grinding tape is easily broken when heated in the wafer thinning process, and at the same time improves the The uniformity of the thickness of the adhesive layer of the multifunctional adhesive during the coating process.

4. The high-efficiency grinding tape for wafer thinning prepared by the present invention can be mixed with phenolic resin, semi-crosslinked powdered nitrile rubber and the weight ratio of 0.3 by using KH550 and organic silicon wetting agent at the same time. : 1.1 triethanolamine and hexamethylenetetramine have effectively improved the compatibility of phenolic resin and semi-crosslinked powdered nitrile rubber in this system through synergistic effects, and at the same time improved the compatibility between multifunctional adhesives and polyurethane elastomer substrates. The cohesion between them, and promote the dispersion uniformity of Al ₂ O ₃ with a particle size of 14 μm on the surface of the adhesive layer, and improve the thinning effect of the abrasive tape on the chip.

5. The high-efficiency grinding tape for wafer thinning prepared by the present invention is based on vinyl acetate, N-methylol acrylamide, and glycidyl methacrylate, and benzoyl peroxide and styrene are added to the system. -Butadiene-styrene block copolymer, nitrile rubber, triethanolamine, hexamethylenetetramine and other substances, the prepared grinding tape has excellent wear resistance, compressive strength, tensile strength, peel strength , has broad application prospects in the field of wafer thinning.

Example

Example 1

Embodiment 1 provides a high-efficiency grinding tape for wafer thinning, and the preparation raw materials include the following components: an elastic resin matrix, a multifunctional adhesive, and abrasive grains.

The elastic resin matrix is polyurethane elastomer, which is purchased from Yuyao Yingcang Plastic Chemical Co., Ltd., and the model is BASF C95A;

The raw materials for the preparation of the multifunctional adhesive include the following components in parts by weight: 80 parts of acrylate compounds, 3 parts of initiators, 5 parts of toughness improvers, 2 parts of organic amine compounds, viscosity modifiers 6 parts, 2 parts of accelerator, 1.5 parts of silane coupling agent, 2 parts of functional auxiliary agent.

The acrylate compound is vinyl acetate, N-methylolacrylamide, glycidyl methacrylate, and the weight ratio of vinyl acetate, N-methylolacrylamide, and glycidyl methacrylate is 1: 0.4:0.8; the CAS number of vinyl acetate is 108-05-4, the CAS number of N-methylolacrylamide is 924-42-5, glycidyl methacrylate was purchased from Weifang Mingran Chemical Co., Ltd. company;

The initiator is benzoyl peroxide; the CAS number of benzoyl peroxide is 94-36-0;

The toughness improver is styrene-butadiene-styrene block copolymer, semi-crosslinked powdered nitrile rubber, styrene-butadiene-styrene block copolymer, semi-crosslinked powder The weight ratio of nitrile rubber is 0.6:1.2; The styrene-butadiene-styrene block copolymer is purchased from Suzhou David New Material Technology Co., Ltd., the model is KratonD1101, and the molar content of styrene is 30%; Combined powdered nitrile rubber is purchased from Hengshui Yisu New Material Technology Co., Ltd., the model is P630, and the molar content of combined acrylonitrile is 33%;

The organic amine compound is triethanolamine and hexamethylenetetramine, and the weight ratio of triethanolamine and hexamethylenetetramine is 0.3:1.1;

The viscosity modifier is phenolic resin, polystyrene, and the weight ratio of phenolic resin and polystyrene is 1.5:0.5; the phenolic resin is purchased from Shandong Jinnaite Environmental Protection Technology Co., Ltd., the model is 2402, methylol The molar content of polystyrene is 9.8%; polystyrene is purchased from Yuyao Yingcang Plastic Chemical Co., Ltd., the model is GPPS GP33, and the melt flow rate at 230°C is 7.2g/10min

The accelerator is hydroquinone; the silane coupling agent is KH550;

The functional additive is a silicone wetting agent, purchased from Shanghai Kaiyin Chemical Co., Ltd., model BYK-333.

The abrasive particles are SiO ₂ purchased from Jinan Hongquan Titanium Industry Co., Ltd., with a particle size of 14 μm, and the added amount is 25% of the weight of the multifunctional adhesive.

The preparation method of the high-efficiency grinding tape for wafer thinning comprises the following steps;

(1) Stir acrylate compounds, toughness modifiers, organic amine compounds, viscosity modifiers, accelerators, silane coupling agents, and functional additives at 70°C to obtain a mixture;

(2) After uniformly coating the mixture described in step (1) on the surface of the substrate, then uniformly coating abrasive grains on the surface of the mixture, adding an initiator, and baking at 75°C for 1 hour, the wafer reduced Thin with efficient abrasive tape.

Wherein, the thickness of the substrate in step (2) is 25 μm.

The thickness of the dry glue in the grinding tape described in step (2) is 140 μm.

Comparative Example 1

The specific implementation method of Comparative Example 1 is the same as that of Example 1, except that no toughness modifier is added.

Comparative Example 2

The specific implementation method of Comparative Example 2 is the same as that of Example 1, except that no viscosity modifier is added.

performance evaluation

(1) Peel strength test

The grinding tape prepared in Example 1 and Comparative Example 1-2 was made into a sample of 120 mm × 30 mm, GB/T2791-1995 "Test Method for Peeling Strength of Adhesive", and the peeling strength of the product was tested. The measured data are shown in Table 1;

(2) Adhesive layer stability performance test

Observe the situation of the adhesive layer during the coating process of the multifunctional adhesive prepared by the scheme of Example 1 and Comparative Example 1-2: if there are no bubbles, it is grade A; if bubbles appear, it is grade B.

Table 1 Performance test results of high-efficiency grinding tape

Claims (10)

1. A wafer thinning high-efficiency grinding tape is characterized in that the preparation raw materials include an elastic resin matrix, a multifunctional adhesive and abrasive grains. 2. The high-efficiency grinding tape according to claim 1, wherein the elastic resin matrix comprises at least one of polyethylene elastomer, polyurethane elastomer, polystyrene elastomer, polyamide elastomer, polypropylene elastomer kind. 3. The high-efficiency grinding tape according to claim 1, wherein the raw materials for the preparation of the multifunctional adhesive comprise the following components in parts by weight: 60-100 parts of acrylate compounds, 1-100 parts of initiator 5 parts, 5-15 parts of toughness improver, 1-3 parts of organic amine compound, 3-10 parts of viscosity modifier, 1-3 parts of accelerator, 1-3 parts of silane coupling agent, 1-3 parts of functional additive 3 copies. 4. according to the described high-efficiency grinding adhesive tape of claim 3, it is characterized in that, described acrylate compound comprises butyl acrylate, isooctyl acrylate, methyl methacrylate, vinyl acetate, N-methylol acrylamide, At least one of glycidyl methacrylate, hydroxyethyl methacrylate, and the like. 5. according to the described high-efficiency abrasive belt of claim 3, it is characterized in that, described toughness improver comprises nitrile rubber, isobutylene rubber, styrene-butadiene-styrene block copolymer, methyl methacrylate-butadiene At least one of diene-styrene terpolymer, oxidized polyethylene, and the like. 6. according to the described high-efficiency abrasive belt of claim 3 or 5, it is characterized in that, described toughness improver is styrene-butadiene-styrene block copolymer, nitrile rubber, styrene-butadiene copolymer , The weight ratio of nitrile rubber is (0.4-1.2): (1-1.5). 7. according to the described high-efficiency grinding adhesive tape of claim 6, it is characterized in that, the molar content of styrene is 25-35% in the described styrene-butadiene-styrene block copolymer; Semi-crosslinked powdered nitrile rubber with a molar content of 30-35%. 8. The high-efficiency grinding tape according to claim 3, wherein the viscosity modifier comprises at least one of terpene resin, petroleum resin, polystyrene, phenolic resin and the like. 9. The high-efficiency grinding tape according to claim 8, characterized in that, the molar content of methylol in the phenolic resin is 8-10%; the melt flow rate of polystyrene at 230°C is 4-10g/10min . 10. A preparation method for high-efficiency grinding tape as claimed in any one of claims 3-9, characterized in that, comprising the following steps; (1) Stir acrylate compounds, toughness modifiers, organic amine compounds, viscosity modifiers, accelerators, silane coupling agents, and functional additives at 60-90°C to obtain a mixture; (2) After uniformly coating the mixture described in step (1) on the surface of the substrate, then uniformly coating the abrasive grains on the surface of the mixture, adding an initiator, and baking at 70-80°C for 0.5-2h to obtain the obtained High-efficiency grinding tape for wafer thinning.