Wafer bonding method

Abstract

The wafer bonding method comprises the following steps that hydrosol is prepared, and the hydrosol comprises a polyurethane adhesive, polyacrylic acid, copolyamide hot melting powder, water, an oxygen resin hardening agent, silicone oil and brominated polystyrene; at normal temperature, spraying the hydrosol to a to-be-bonded surface of a wafer by using a spraying device, and controlling the supply rate of the hydrosol to be 0.08-0.12 ml / s and the width of a glue drop to be 15-20 mm by using the spraying device; and bonding the to-be-bonded surface of the wafer on a machine table and curing the to-be-bonded surface of the wafer. According to the invention, the possibility of fragmentation or damage of the wafer in the subsequent process can be reduced.

Description

Technical Field

[0001] The invention relates to the field of semiconductor processing, and in particular to a wafer bonding method. Background Art

[0002] With the development of science and technology, semiconductor chips are increasingly widely used, and the requirements for their processing accuracy are also getting higher and higher. For example, in the process of wafer processing, grinding to thin the wafer or cutting the wafer into long strips is a common processing technology. Usually, the wafer is bonded to the fixture with photoresist before wafer processing. However, the photoresist is very hard after curing. In the subsequent grinding or cutting, the vibration of the grinding wheel can easily cause the wafer to break and seriously damage the wafer.

[0003] Therefore, it is urgent to provide an improved wafer bonding method to overcome the above defects. Summary of the invention

[0004] The object of the present invention is to provide an improved wafer bonding method to reduce the problem of wafer fragmentation.

[0005] To achieve the above object, the present invention provides a wafer bonding method, comprising the following steps:

[0006] preparing a hydrosol, wherein the hydrosol comprises a polyurethane adhesive, polyacrylic acid, copolyamide hot melt powder, water, epoxy resin hardener, silicone oil and brominated polystyrene;

[0007] At room temperature, using a spraying device to spray the hydrosol onto the surface to be bonded of the wafer, wherein the spraying device controls the supply rate of the hydrosol to be 0.08-0.12 ml / s and the width of the glue droplet to be 15-20 mm; and

[0008] The surface to be bonded of the wafer is bonded to a machine platform and cured.

[0009] Compared with the prior art, the present invention uses a hydrosol of a specific component to replace photoresist as an adhesive, and uses a spraying device to spray the hydrosol on the surface of the wafer to be bonded. Moreover, the supply rate of the hydrosol and the width of the glue droplets are controlled within a specific range to obtain a better spraying effect and improve uniformity. Finally, the bonding is cured to achieve fixed bonding. The hydrosol plays a shock-absorbing role, thereby reducing the force on the wafer during bonding and in subsequent processes after bonding, thereby reducing the possibility of its fragmentation; the hydrosol replaces the traditional photoresist bonding, and the yield rate is greatly improved.

[0010] Preferably, the spraying device comprises a plurality of nozzles, and the spacing between the plurality of nozzles is 25-30 mm.

[0011] Preferably, the air compression force in the multiple nozzles is 45-120 atm.

[0012] Preferably, the method further comprises: controlling the moving speed of the nozzle of the spraying device and the distance between the nozzle and the surface to be bonded of the wafer.

[0013] Preferably, the moving speed is 0.8 cm / s-2.0 cm / s, and the distance is 0.8 mm-1.5 mm.

[0014] Preferably, the step of bonding the surface to be bonded of the wafer to a machine platform and curing the surface includes: placing the surface to be bonded of the wafer on a predetermined surface of the machine platform, applying force to the back side of the wafer, and squeezing out bubbles between the wafer and the machine platform.

[0015] Preferably, the step of bonding the surface to be bonded of the wafer to a machine platform and curing the surface further comprises: dripping curing glue between the surface to be bonded and the predetermined surface.

[0016] Preferably, the hydrosol comprises the following components: 61-70% polyurethane adhesive, 4-8% polyacrylic acid, 20-28% copolyamide hot melt powder, 3-5% water, 0.5-2% epoxy resin hardener, 0.3-0.9% silicone oil and 0.2-0.7% brominated polystyrene.

[0017] More preferably, the hydrosol comprises the following components: 64% polyurethane adhesive, 6% polyacrylic acid, 24% copolyamide hot melt powder, 4% water, 1% epoxy resin hardener, 0.5% silicone oil and 0.5% brominated polystyrene. DETAILED DESCRIPTION

[0018] The wafer bonding method of the present invention is further described below in conjunction with the embodiments, but the present invention is not limited thereby. The method of the present invention aims to provide a wafer bonding method to reduce the problem of wafer fragmentation.

[0019] An embodiment of a semiconductor wafer bonding method of the present invention comprises the following steps:

[0020] preparing a hydrosol, wherein the hydrosol comprises a polyurethane adhesive, polyacrylic acid, copolyamide hot melt powder, water, epoxy resin hardener, silicone oil and brominated polystyrene;

[0021] At room temperature, using a spraying device to spray the hydrosol onto the surface to be bonded of the wafer, wherein the spraying device controls the supply rate of the hydrosol to be 0.08-0.12 ml / s and the width of the glue droplet to be 15-20 mm; and

[0022] The surface to be bonded of the wafer is bonded to a machine platform and cured.

[0023] The present invention uses a hydrosol of a specific component to replace photoresist as an adhesive, and uses a spraying device to spray the hydrosol on the surface to be bonded of the wafer. Moreover, the supply rate of the hydrosol and the width of the glue drop are controlled within a specific range to obtain a better spraying effect and improve uniformity. Finally, the bonding is cured to achieve fixed bonding. The hydrosol plays a shock-absorbing role, thereby reducing the force on the wafer during bonding and in subsequent processes after bonding, thereby reducing the possibility of its fragmentation; the hydrosol replaces the traditional photoresist bonding, and the yield rate is greatly improved.

[0024] Specifically, as a preferred embodiment, the hydrosol includes the following components: 61-70% polyurethane adhesive, 4-8% polyacrylic acid, 20-28% copolyamide hot melt powder, 3-5% water, 0.5-2% epoxy resin hardener, 0.3-0.9% silicone oil and 0.2-0.7% brominated polystyrene. The hydrosol of this specific component has suitable viscosity and fluidity, which is conducive to spraying and bonding, and the hydrosol is simple and easy to obtain, and has low cost. More preferably, the hydrosol includes the following components: 64% polyurethane adhesive, 6% polyacrylic acid, 24% copolyamide hot melt powder, 4% water, 1% epoxy resin hardener, 0.5% silicone oil and 0.5% brominated polystyrene.

[0025] The hydrosol is sprayed toward the wafer by a spraying device. Specifically, the container carrying the hydrosol is usually a syringe-shaped stainless steel tube, the head is a stainless steel nozzle, and the rear is connected to a compressed air pipe. The hydrosol inside is pressurized by compressed air so that it is sprayed out from the front nozzle and evenly coated on the front of the wafer. Specifically, by controlling the compression force of the compressed air to 45-120atm, the supply rate of the hydrosol is 0.08-0.12ml / s, and the width of the glue drop is 15-20mm. In addition, when spraying, the moving speed of the nozzle of the spraying device and the distance between the nozzle and the surface to be bonded of the wafer should also be controlled. Preferably, the moving speed of the nozzle is 0.8cm / s-2.0cm / s, and the distance between the nozzle and the surface to be bonded of the wafer is 0.8mm-1.5mm.

[0026] In some embodiments of the present invention, the number of nozzles may be one or more, and accordingly, multiple nozzles are arranged at a certain interval to spray wax to different parts of the wafer at the same time, and the above-mentioned parameters such as the nozzle movement speed and the wax dripping width can be adjusted according to actual conditions and are not limited here. For example, when there are five nozzles, the nozzle spacing is 25-30mm, and the compression force of the compressed air is controlled to be 45-60atm; when there are ten nozzles, the nozzle spacing is 25-30mm, and the compression force of the compressed air is controlled to be 90-120atm.

[0027] After the hydrosol is sprayed, the wafer is removed and the surface to be bonded of the wafer is butted against the predetermined surface of the machine. With the help of the hydrosol, the surface to be bonded of the wafer is temporarily and partially bonded to the predetermined surface of the machine to form a shock-absorbing surface. It should be noted that the bonding force is not strong at this time, and the wafer cannot be completely fixed on the machine. Preferably, before dripping the curing glue, force is applied to the back of the wafer to make the hydrosol between the wafer and the machine more uniform, and at the same time, the bubbles are squeezed out and the thickness of the hydrosol is also uniform, for example, maintained at 0.5mm.

[0028] Then, curing glue, such as 502 curing glue, is injected into the edge between the surface to be bonded of the wafer and the predetermined surface of the machine platform, so that the wafer is completely bonded to the machine platform. Based on this, the wafer can be processed accordingly.

[0029] The present invention uses a hydrosol of a specific component to replace photoresist as an adhesive, and uses a spraying device to spray the hydrosol onto the surface to be bonded of the wafer. Moreover, the supply rate of the hydrosol and the width of the glue droplets are controlled within a specific range to obtain a better spraying effect and improve uniformity. Finally, the bonding is cured to achieve fixed bonding. The hydrosol plays a shock-absorbing role, thereby reducing the force on the wafer during bonding and in subsequent processes after bonding, thereby reducing the possibility of its fragmentation; the hydrosol replaces the traditional photoresist bonding, the yield rate is greatly improved, and the possibility of wafer fragmentation or damage in subsequent processing procedures is greatly reduced.

[0030] The above disclosure is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A wafer bonding method, characterized in that: The following steps are involved: preparing a hydrosol, wherein the hydrosol comprises a polyurethane adhesive, polyacrylic acid, copolyamide hot melt powder, water, epoxy resin hardener, silicone oil and brominated polystyrene; At room temperature, using a spraying device to spray the hydrosol onto the surface to be bonded of the wafer, wherein the spraying device controls the supply rate of the hydrosol to be 0.08-0.12 ml / s and the width of the glue droplet to be 15-20 mm; and The surface to be bonded of the wafer is bonded to a machine platform and cured.

2. The wafer bonding method according to claim 1, wherein: The spraying device comprises a plurality of nozzles, and the spacing between the plurality of nozzles is 25-30 mm.

3. The wafer bonding method according to claim 2, wherein: The air compression force in the multiple nozzles is 45-120atm.

4. The wafer bonding method according to claim 2, characterized in that: Also includes: The moving speed of the nozzle of the spraying device and the distance between the nozzle and the surface to be bonded of the wafer are controlled.

5. The wafer bonding method according to claim 4, wherein: The moving speed is 0.8 cm / s-2.0 cm / s, and the distance is 0.8 mm-1.5 mm.

6. The wafer bonding method according to claim 1, wherein: The step of bonding the surface to be bonded of the wafer to a platform and curing the surface includes: placing the surface to be bonded of the wafer on a predetermined surface of the platform, applying force to the back of the wafer, and squeezing out bubbles between the wafer and the platform.

7. The wafer bonding method according to claim 6, wherein: The step of bonding the surface to be bonded of the wafer to a machine platform and curing the surface further includes: dripping curing glue between the surface to be bonded and the predetermined surface.

8. The wafer bonding method according to claim 1, wherein: The hydrosol comprises the following components: 61-70% of polyurethane adhesive, 4-8% of polyacrylic acid, 20-28% of copolyamide hot melt powder, 3-5% of water, 0.5-2% of epoxy resin hardener, 0.3-0.9% of silicone oil and 0.2-0.7% of brominated polystyrene.

9. The wafer bonding method according to claim 8, characterized in that: The hydrosol comprises the following components: 64% polyurethane adhesive, 6% polyacrylic acid, 24% copolyamide hot melt powder, 4% water, 1% epoxy resin hardener, 0.5% silicone oil and 0.5% brominated polystyrene.