Bonding method of silicon wafer

Abstract

The invention discloses a bonding method of a silicon wafer. The bonding method comprises the following steps: cleaning the silicon wafer; uniformly coating the front surface of the cleaned silicon wafer with the prefabricated hydrosol by using spraying equipment; bonding the front surface of the glued silicon wafer on the surface of a machine table, and applying a preset force to the back surface of the glued silicon wafer; and dripping curing glue on the edge of the contact surface of the machine table and the glued silicon wafer so as to bond the glued silicon wafer on the surface of the machine table. According to the technical scheme, the hydrosol is used for bonding the silicon wafer, the problem that the silicon wafer is prone to fragmentation in the machining process can be solved, the fragmentation condition of the silicon wafer is greatly reduced, and therefore the yield is increased.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and more particularly to a method for bonding silicon wafers. Background Technology

[0002] Currently, in the processing of silicon wafers, adhesives are typically used for curing and bonding, attaching the wafers to machine tools for cutting and grinding. However, the vibrations generated during processing (e.g., the vibration of the grinding wheel) can easily cause the silicon wafers to break, thus affecting the yield. Summary of the Invention

[0003] The purpose of this invention is to provide a method for bonding silicon wafers. By using a water-soluble adhesive to bond the silicon wafers, the problem of silicon wafers easily breaking during processing can be solved, significantly reducing the occurrence of silicon wafer breakage and thus improving the yield.

[0004] To achieve the above objectives, embodiments of the present invention provide a method for bonding silicon wafers, comprising:

[0005] The silicon wafers are cleaned.

[0006] The pre-made hydrosol is evenly coated onto the front side of the cleaned silicon wafer using a spraying device;

[0007] The front side of the coated silicon wafer is bonded to the surface of the machine, and a preset force is applied to the back side of the coated silicon wafer.

[0008] Apply curing adhesive to the edge of the contact surface between the machine and the coated silicon wafer to bond the coated silicon wafer to the surface of the machine.

[0009] Furthermore, the hydrosol is composed of 60% polyurethane adhesive, 7.5% polyacrylic acid, 15% PA hot melt powder, 15.5% water, 1% epoxy resin hardener, 0.5% silicone oil and 0.5% brominated polystyrene.

[0010] Furthermore, the spraying equipment is a syringe-shaped stainless steel tube, the head of the stainless steel tube includes at least one nozzle, and the tail of the stainless steel tube includes a compressed air pipe communicating with the at least one nozzle.

[0011] Furthermore, when the head of the stainless steel tube includes more than one nozzle, the distance between two adjacent nozzles is 10-12 mm.

[0012] Furthermore, when the head of the stainless steel tube includes a nozzle, the process of uniformly applying a pre-prepared hydrosol to the front surface of the cleaned silicon wafer using a spraying device specifically involves:

[0013] Under the conditions of compressed air compression force of 12-15 atm and water-soluble adhesive supply rate of 0.15-0.18 ml / s, the pre-prepared water-soluble adhesive is uniformly sprayed onto the front side of the cleaned silicon wafer using the nozzle of the stainless steel tube.

[0014] Furthermore, when the head of the stainless steel tube includes five nozzles, the process of uniformly applying a pre-prepared hydrosol to the front surface of the cleaned silicon wafer using a spraying device specifically involves:

[0015] Under the conditions of compressed air compression of 75-80 atm and hydrosol supply rate of 0.10-0.12 ml / s, the pre-prepared hydrosol is uniformly sprayed onto the front side of the cleaned silicon wafer using the nozzle of the stainless steel tube.

[0016] Furthermore, when the head of the stainless steel tube includes ten nozzles, the process of uniformly applying a pre-prepared hydrosol to the front surface of the cleaned silicon wafer using a spraying device specifically involves:

[0017] Under the conditions of compressed air compression force of 160-200 atm and water-soluble adhesive supply rate of 0.08-0.10 ml / s, the pre-prepared water-soluble adhesive is uniformly sprayed onto the front side of the cleaned silicon wafer using the nozzle of the stainless steel tube.

[0018] Furthermore, the diameter of the adhesive droplets on the front side of the coated silicon wafer is 1.5–2.0 mm, and the distance between two adjacent adhesive droplets is 1.5–2.0 mm.

[0019] Furthermore, the preset force is a force of 10 to 12 kg.

[0020] Furthermore, the thickness of the adhesive layer between the machine and the coated silicon wafer is 0.5 mm.

[0021] Compared with existing technologies, this invention provides a method for bonding silicon wafers. First, the silicon wafer is cleaned. Next, a pre-prepared hydrosol is evenly applied to the front side of the cleaned silicon wafer using a spraying device. Then, the front side of the coated silicon wafer is bonded to the surface of a machine, and a predetermined force is applied to the back side of the coated silicon wafer. Finally, curing adhesive is dripped onto the edge of the contact surface between the machine and the coated silicon wafer to bond the coated silicon wafer to the machine surface. This invention, by using hydrosol to bond silicon wafers, solves the problem of silicon wafers easily breaking during processing, significantly reducing the breakage rate and thus improving the yield. Attached Figure Description

[0022] Figure 1 This is a flowchart of a preferred embodiment of a silicon wafer bonding method provided by the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] This invention provides a method for bonding silicon wafers, see [link to relevant documentation]. Figure 1 The diagram shown is a flowchart of a preferred embodiment of a silicon wafer bonding method provided by the present invention, the method comprising steps S11 to S14:

[0025] Step S11: Clean the silicon wafer;

[0026] Step S12: Use a spraying device to evenly coat the pre-made hydrosol onto the front side of the cleaned silicon wafer;

[0027] Step S13: Adhere the front side of the coated silicon wafer to the surface of the machine, and apply a preset force to the back side of the coated silicon wafer.

[0028] Step S14: Apply curing adhesive to the edge of the contact surface between the machine and the coated silicon wafer to bond the coated silicon wafer to the surface of the machine.

[0029] In practice, the silicon wafer is first cleaned to ensure it is thoroughly cleaned. Then, at room temperature, a pre-prepared hydrosol is evenly applied to the front side of the cleaned silicon wafer using a spraying device carrying hydrosol. Next, the hydrosol-coated front side of the silicon wafer is bonded to the surface of the machine (i.e., the hydrosol-coated front side of the silicon wafer is in contact with the surface of the machine), and a predetermined force is applied to the back side of the hydrosol-coated silicon wafer to ensure more even application of the hydrosol between the front side of the silicon wafer and the surface of the machine, while simultaneously squeezing out air bubbles from the hydrosol. Finally, curing adhesive (e.g., 502 curing adhesive) is dripped onto the edge of the contact surface between the machine and the coated silicon wafer (i.e., the outer edge of the front side of the silicon wafer) to bond the hydrosol-coated silicon wafer to the surface of the machine and to ensure a more secure bond.

[0030] It should be noted that after the silicon wafer is bonded to the surface of the machine, subsequent processing such as cutting and grinding can be performed on the silicon wafer. Furthermore, because the silicon wafer is firmly bonded to the surface of the machine, the occurrence of silicon wafer breakage during processing is greatly reduced.

[0031] In one alternative embodiment, the hydrosol consists of 60% polyurethane adhesive, 7.5% polyacrylic acid, 15% PA hot melt powder, 15.5% water, 1% epoxy resin hardener, 0.5% silicone oil and 0.5% brominated polystyrene.

[0032] Specifically, in conjunction with the above embodiments, the water-soluble adhesive used in the embodiments of the present invention is pre-prepared from polyurethane adhesive, polyacrylic acid, PA hot melt powder, water, epoxy resin curing agent, silicone oil, and brominated polystyrene, and the content of each component is as follows: polyurethane adhesive 60%, polyacrylic acid 7.5%, PA hot melt powder 15%, water 15.5%, epoxy resin curing agent 1%, silicone oil 0.5%, and brominated polystyrene 0.5%.

[0033] In one alternative embodiment, the spraying device is a syringe-shaped stainless steel tube, the head of which includes at least one nozzle, and the tail of which includes a compressed air conduit communicating with the at least one nozzle.

[0034] Specifically, in conjunction with the above embodiments, when using a spraying device to uniformly coat the pre-made hydrosol onto the front side of the cleaned silicon wafer, the spraying device used is typically a syringe-shaped stainless steel tube. The head of the stainless steel tube includes at least one nozzle (i.e., a stainless steel nozzle), and the tail of the stainless steel tube includes a compressed air pipe connected to at least one nozzle. The interior of the stainless steel tube has a space to carry the hydrosol. It can be understood that by pressurizing with compressed air, the hydrosol inside the stainless steel tube can be sprayed out from at least one nozzle at the head, thereby uniformly spraying the hydrosol onto the front side of the silicon wafer.

[0035] In one alternative embodiment, when the head of the stainless steel tube includes more than one nozzle, the spacing between two adjacent nozzles is 10 to 12 mm.

[0036] Specifically, in conjunction with the above embodiments, the head of the stainless steel pipe may have only one nozzle or multiple nozzles. When there is more than one nozzle, the distance between any two adjacent nozzles is in the range of 10mm to 12mm.

[0037] For example, the distance between two adjacent nozzles can be 10mm, 11mm or 12mm, or it can be set according to actual needs. This embodiment of the invention does not make specific limitations.

[0038] In one optional embodiment, when the head of the stainless steel tube includes a nozzle, the application of a pre-prepared hydrosol to the front surface of the cleaned silicon wafer using a spraying device specifically involves:

[0039] Under the conditions of compressed air compression force of 12-15 atm and water-soluble adhesive supply rate of 0.15-0.18 ml / s, the pre-prepared water-soluble adhesive is uniformly sprayed onto the front side of the cleaned silicon wafer using the nozzle of the stainless steel tube.

[0040] Specifically, in conjunction with the above embodiments, if the head of the stainless steel tube includes only one nozzle, then when the pre-prepared hydrosol is uniformly coated on the front side of the cleaned silicon wafer using a spraying device, the pre-prepared hydrosol can be uniformly sprayed onto the front side of the cleaned silicon wafer using one nozzle of the stainless steel tube under the conditions of compressed air compression force of 12 atm to 15 atm and hydrosol supply rate of 0.15 ml / s to 0.18 ml / s.

[0041] For example, when the head of the stainless steel pipe includes only one nozzle, the compressed air compression force can be 12 atm, 13 atm, 14 atm or 15 atm, and can also be set according to actual needs. This embodiment of the invention does not make specific limitations.

[0042] For example, when the head of the stainless steel tube includes only one nozzle, the supply rate of the hydrosol can be 0.15 ml / s, 0.16 ml / s, 0.17 ml / s or 0.18 ml / s, or can be set according to actual needs. This embodiment of the invention does not impose specific limitations.

[0043] In one optional embodiment, when the head of the stainless steel tube includes five nozzles, the application of a pre-prepared hydrosol to the front surface of the cleaned silicon wafer using a spraying device specifically involves:

[0044] Under the conditions of compressed air compression of 75-80 atm and hydrosol supply rate of 0.10-0.12 ml / s, the pre-prepared hydrosol is uniformly sprayed onto the front side of the cleaned silicon wafer using the nozzle of the stainless steel tube.

[0045] Specifically, in conjunction with the above embodiments, if the head of the stainless steel tube includes more than one nozzle, for example, five nozzles, then when the pre-prepared hydrosol is uniformly coated onto the front side of the cleaned silicon wafer using a spraying device, the pre-prepared hydrosol can be uniformly sprayed onto the front side of the cleaned silicon wafer using the five nozzles of the stainless steel tube under the conditions of compressed air compression force of 75 atm to 80 atm and hydrosol supply rate of 0.10 ml / s to 0.12 ml / s.

[0046] For example, when the head of the stainless steel pipe includes five nozzles, the compressed air compression force can be 75 atm, 76 atm, 77 atm, 78 atm, 79 atm or 80 atm, and can also be set according to actual needs. This embodiment of the invention does not make specific limitations.

[0047] For example, when the head of the stainless steel tube includes five nozzles, the supply rate of the hydrosol can be 0.10 ml / s, 0.11 ml / s or 0.12 ml / s, or can be set according to actual needs. This embodiment of the invention does not impose specific limitations.

[0048] In one optional embodiment, when the head of the stainless steel tube includes ten nozzles, the process of uniformly applying a pre-prepared hydrosol to the front surface of the cleaned silicon wafer using a spraying device specifically involves:

[0049] Under the conditions of compressed air compression force of 160-200 atm and water-soluble adhesive supply rate of 0.08-0.10 ml / s, the pre-prepared water-soluble adhesive is uniformly sprayed onto the front side of the cleaned silicon wafer using the nozzle of the stainless steel tube.

[0050] Specifically, in conjunction with the above embodiments, if the head of the stainless steel tube includes more than one nozzle, for example, ten nozzles, then when the pre-prepared hydrosol is uniformly coated on the front side of the cleaned silicon wafer using a spraying device, the pre-prepared hydrosol can be uniformly sprayed onto the front side of the cleaned silicon wafer using the ten nozzles of the stainless steel tube under the conditions of compressed air compression force of 160 atm to 200 atm and hydrosol supply rate of 0.08 ml / s to 0.10 ml / s.

[0051] For example, when the head of the stainless steel pipe includes ten nozzles, the compressed air compression force can be 160atm, 165atm, 170atm, 175atm, 180atm, 185atm, 190atm, 195atm or 200atm, and can also be set according to actual needs. This embodiment of the invention does not make specific limitations.

[0052] For example, when the head of the stainless steel tube includes ten nozzles, the supply rate of the hydrosol can be 0.08 ml / s, 0.09 ml / s, or 0.10 ml / s, and can also be set according to actual needs. This embodiment of the invention does not impose specific limitations.

[0053] In one optional embodiment, the diameter of the adhesive droplets on the front side of the coated silicon wafer is 1.5 to 2.0 mm, and the distance between two adjacent adhesive droplets is 1.5 to 2.0 mm.

[0054] Specifically, in conjunction with the above embodiments, after uniformly spraying the pre-prepared hydrosol onto the front side of the cleaned silicon wafer using a nozzle on a stainless steel tube, the diameter (or width) of the adhesive droplets formed on the front side of the silicon wafer is in the range of 1.5mm to 2.0mm, and the distance between each two adjacent adhesive droplets is in the range of 1.5mm to 2.0mm.

[0055] For example, the diameter of the adhesive droplet can be 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm or 2.0mm, and can also be set according to actual needs. This embodiment of the invention does not make specific limitations.

[0056] For example, the distance between two adjacent droplets can be 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm or 2.0mm, and can also be set according to actual needs. This embodiment of the invention does not impose specific limitations.

[0057] In one optional embodiment, the preset force is a force of 10 to 12 kg.

[0058] Specifically, in conjunction with the above embodiments, after the front side of the silicon wafer coated with hydrosol is bonded to the surface of the machine, a preset force of 10kg to 12kg is applied to the back side of the silicon wafer coated with hydrosol to make the hydrosol between the front side of the silicon wafer and the surface of the machine more evenly coated, while squeezing out air bubbles in the hydrosol.

[0059] For example, the preset force value can be 10kg, 11kg or 12kg, or it can be set according to actual needs. This embodiment of the invention does not make specific limitations.

[0060] In one optional embodiment, the thickness of the adhesive layer between the machine and the coated silicon wafer is 0.5 mm.

[0061] Specifically, in conjunction with the above embodiments, after the front side of the silicon wafer coated with hydrosol is bonded to the surface of the machine, a force of 10kg to 12kg can be applied to the back side of the silicon wafer coated with hydrosol to keep the thickness of the adhesive layer between the machine and the silicon wafer coated with hydrosol at 0.5mm.

[0062] In conjunction with all the above embodiments, when the spraying equipment is a syringe-shaped stainless steel tube, and the head of the stainless steel tube includes five nozzles (the distance between two adjacent nozzles is 10mm), the implementation process of this solution is described below through the first specific embodiment, including: (1) cleaning the silicon wafer to clean it; (2) at room temperature, using the syringe-shaped stainless steel tube carrying the hydrosol, under the conditions of compressed air compression force of 75atm and hydrosol supply rate of 0.10ml / s, the five nozzles of the stainless steel tube uniformly spray the pre-prepared hydrosol onto the front side of the cleaned silicon wafer, forming multiple droplets with a diameter (or width) of 1.5mm on the front side of the silicon wafer, and the distance between each two adjacent droplets is 1.5mm; wherein, water The sol consists of 60% polyurethane adhesive, 7.5% polyacrylic acid, 15% PA hot melt powder, 15.5% water, 1% epoxy resin hardener, 0.5% silicone oil and 0.5% brominated polystyrene; (3) the front side of the silicon wafer coated with the water sol is bonded to the surface of the machine, and a force of 10 kg is applied to the back side of the silicon wafer coated with the water sol, so that the water sol between the front side of the silicon wafer and the surface of the machine can be coated more evenly, while squeezing out the air bubbles in the water sol, and the thickness of the adhesive layer between the machine and the silicon wafer coated with the water sol is kept at 0.5 mm; (4) a curing adhesive (e.g., 502 curing adhesive) is dripped into the edge of the contact surface between the machine and the coated silicon wafer to bond the silicon wafer coated with the water sol more firmly to the surface of the machine.

[0063] In conjunction with all the above embodiments, when the spraying equipment is a syringe-shaped stainless steel tube and the head of the stainless steel tube includes five nozzles (the distance between two adjacent nozzles is 10mm), the implementation process of this solution is described below through a second specific embodiment, including: (1) cleaning the silicon wafer to clean it; (2) at room temperature, using the syringe-shaped stainless steel tube carrying the hydrosol, under the conditions of compressed air compression force of 78atm and hydrosol supply rate of 0.11ml / s, the five nozzles of the stainless steel tube uniformly spray the pre-prepared hydrosol onto the front side of the cleaned silicon wafer, forming multiple droplets with a diameter (or width) of 1.7mm on the front side of the silicon wafer, and the distance between each two adjacent droplets is 1.7mm; wherein, water The sol consists of 60% polyurethane adhesive, 7.5% polyacrylic acid, 15% PA hot melt powder, 15.5% water, 1% epoxy resin hardener, 0.5% silicone oil and 0.5% brominated polystyrene; (3) the front side of the silicon wafer coated with the water sol is bonded to the surface of the machine, and a force of 11 kg is applied to the back side of the silicon wafer coated with the water sol, so that the water sol between the front side of the silicon wafer and the surface of the machine can be coated more evenly, while squeezing out the air bubbles in the water sol, and the thickness of the adhesive layer between the machine and the silicon wafer coated with the water sol is kept at 0.5 mm; (4) a curing adhesive (e.g., 502 curing adhesive) is dripped onto the edge of the contact surface between the machine and the coated silicon wafer to bond the coated silicon wafer more firmly to the surface of the machine.

[0064] In conjunction with all the above embodiments, when the spraying equipment is a syringe-shaped stainless steel tube and the head of the stainless steel tube includes five nozzles (the distance between two adjacent nozzles is 10mm), the implementation process of this solution is described below through a third specific embodiment, including: (1) cleaning the silicon wafer to clean it; (2) at room temperature, using the syringe-shaped stainless steel tube carrying the hydrosol, under the conditions of compressed air compression force of 80atm and hydrosol supply rate of 0.12ml / s, the five nozzles of the stainless steel tube uniformly spray the pre-prepared hydrosol onto the front side of the cleaned silicon wafer, forming multiple droplets with a diameter (or width) of 2.0mm on the front side of the silicon wafer, and the distance between each two adjacent droplets is 2.0mm; wherein, water The sol consists of 60% polyurethane adhesive, 7.5% polyacrylic acid, 15% PA hot melt powder, 15.5% water, 1% epoxy resin hardener, 0.5% silicone oil and 0.5% brominated polystyrene; (3) the front side of the silicon wafer coated with the water sol is bonded to the surface of the machine, and a force of 12 kg is applied to the back side of the silicon wafer coated with the water sol, so that the water sol between the front side of the silicon wafer and the surface of the machine can be coated more evenly, while squeezing out the air bubbles in the water sol, and the thickness of the adhesive layer between the machine and the silicon wafer coated with the water sol is kept at 0.5 mm; (4) a curing adhesive (e.g., 502 curing adhesive) is dripped onto the edge of the contact surface between the machine and the coated silicon wafer to bond the coated silicon wafer more firmly to the surface of the machine.

[0065] In summary, the silicon wafer bonding method provided by this invention involves: first, cleaning the silicon wafer; then, uniformly applying a pre-prepared water-soluble adhesive to the front side of the cleaned silicon wafer using a spraying device; next, bonding the adhesive-coated front side of the silicon wafer to the surface of a machine, and applying a predetermined force to the back side of the adhesive-coated silicon wafer; finally, dripping curing adhesive onto the edge of the contact surface between the machine and the adhesive-coated silicon wafer to bond the adhesive-coated silicon wafer to the surface of the machine. This invention, by using water-soluble adhesive to bond silicon wafers, solves the problem of silicon wafers easily breaking during processing, significantly reducing the occurrence of silicon wafer breakage and thus improving the yield rate.

[0066] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for bonding silicon wafers, characterized in that, include: The silicon wafers are cleaned. The pre-made hydrosol is evenly coated onto the front side of the cleaned silicon wafer using a spraying device; The front side of the coated silicon wafer is bonded to the surface of the machine, and a preset force is applied to the back side of the coated silicon wafer. Apply curing adhesive to the edge of the contact surface between the machine and the coated silicon wafer to bond the coated silicon wafer to the surface of the machine.

2. The bonding method for silicon wafers as described in claim 1, characterized in that, The hydrosol is composed of 60% polyurethane adhesive, 7.5% polyacrylic acid, 15% PA hot melt powder, 15.5% water, 1% epoxy resin hardener, 0.5% silicone oil and 0.5% brominated polystyrene.

3. The bonding method for silicon wafers as described in claim 1, characterized in that, The spraying equipment is a needle-shaped stainless steel tube, the head of which includes at least one nozzle, and the tail of which includes a compressed air pipe communicating with the at least one nozzle.

4. The bonding method for silicon wafers as described in claim 3, characterized in that, When the head of the stainless steel tube includes more than one nozzle, the distance between two adjacent nozzles is 10-12 mm.

5. The bonding method for silicon wafers as described in claim 3, characterized in that, When the head of the stainless steel tube includes a nozzle, the process of uniformly applying a pre-prepared hydrosol to the front side of the cleaned silicon wafer using a spraying device specifically involves: Under the conditions of compressed air compression force of 12-15 atm and water-soluble adhesive supply rate of 0.15-0.18 ml / s, the pre-prepared water-soluble adhesive is uniformly sprayed onto the front side of the cleaned silicon wafer using the nozzle of the stainless steel tube.

6. The bonding method for silicon wafers as described in claim 3, characterized in that, When the head of the stainless steel tube includes five nozzles, the process of uniformly applying a pre-prepared hydrosol to the front side of the cleaned silicon wafer using a spraying device specifically involves: Under the conditions of compressed air compression of 75-80 atm and hydrosol supply rate of 0.10-0.12 ml / s, the pre-prepared hydrosol is uniformly sprayed onto the front side of the cleaned silicon wafer using the nozzle of the stainless steel tube.

7. The bonding method for silicon wafers as described in claim 3, characterized in that, When the head of the stainless steel tube includes ten nozzles, the process of uniformly applying a pre-prepared hydrosol to the front surface of the cleaned silicon wafer using a spraying device specifically involves: Under the conditions of compressed air compression force of 160-200 atm and water-soluble adhesive supply rate of 0.08-0.10 ml / s, the pre-prepared water-soluble adhesive is uniformly sprayed onto the front side of the cleaned silicon wafer using the nozzle of the stainless steel tube.

8. The bonding method for silicon wafers as described in claim 3, characterized in that, The diameter of the adhesive droplets on the front side of the coated silicon wafer is 1.5 to 2.0 mm, and the distance between two adjacent adhesive droplets is 1.5 to 2.0 mm.

9. The bonding method for silicon wafers as described in claim 1, characterized in that, The preset force is 10-12 kg.

10. The bonding method for silicon wafers as described in claim 1, characterized in that, The thickness of the adhesive layer between the machine and the coated silicon wafer is 0.5 mm.

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