A method for attaching a wafer to a glass carrier

Abstract

The present invention provides a method for attaching a wafer and a glass carrier, and relates to the field of wafer processing technology. The method for attaching a wafer and a glass carrier comprises the following steps: S1, wafer thinning, attaching the front side of the wafer that has completed the front half of the process to a grinding tape with UV glue, so that the back side of the wafer faces upward, and then using automated equipment to thin the back side of the wafer; S2, attaching the first carrier, and spraying deionized water on the first carrier. The method for attaching a wafer and a glass carrier provided by the present invention uses a grinding tape with UV glue to carry the wafer during the process of grinding and thinning the wafer, thereby providing protection for the wafer, and then attaching the wafer to the second carrier by coating SOG and a water film, which is convenient for positioning the wafer and avoiding position deviation between the wafer and the second carrier, and then evaporating the water film by constant temperature drying, so that there is no need to use colloid bonding between the wafer and the second carrier, so that the wafer and the second carrier can be fully attached.

Description

Technical Field

[0001] The invention relates to the technical field of wafer processing, and in particular to a method for attaching a wafer and a glass carrier. Background Art

[0002] A wafer refers to a silicon chip used to make silicon semiconductor circuits. Its original material is silicon. High-purity polycrystalline silicon is dissolved and doped with silicon crystal seeds, which are then slowly pulled out to form cylindrical single crystal silicon. After grinding, polishing, and slicing, the silicon crystal rod forms a silicon wafer, or wafer.

[0003] In order to facilitate the processing and transfer of wafers during wafer processing, a carrier is usually used as a medium to carry the wafers. In the prior art, the wafers are usually bonded to the carrier with an adhesive, resulting in a lack of protection for the wafer during the grinding and thinning process of the wafer, and it is not convenient to quickly align the wafer to the carrier. The presence of adhesive between the carrier and the wafer makes it impossible for the carrier and the wafer to fit fully. Summary of the invention

[0004] In order to solve the deficiencies mentioned in the above background technology, the purpose of the present invention is to provide a method for attaching a wafer and a glass carrier to solve the problem that the wafer is usually bonded to the carrier through an adhesive, resulting in a lack of protection for the wafer during the grinding and thinning process.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A method for attaching a wafer to a glass carrier comprises the following steps:

[0007] S1, wafer thinning, the front side of the wafer that has completed the first half of the front side process is attached to the grinding tape with UV glue, so that the back side of the wafer faces upward, and then the back side of the wafer is thinned by automated equipment;

[0008] S2, attaching the first carrier, spraying deionized water onto the first carrier to form a water film of uniform thickness on the first carrier, then flipping the wafer obtained in step S1 through a flipping device, and then attaching the back side of the wafer to the first carrier through the water film;

[0009] S3, removing the grinding tape, irradiating the wafer with UV light of a specific wavelength to weaken the UV adhesive on the grinding tape, and finally removing the grinding tape upwards with a semi-automatic device;

[0010] S4, attaching the second carrier, spraying deionized water on the front side of the wafer obtained in step S3 to form a water film with uniform thickness, and then attaching the second carrier to the front side of the wafer through the water film on the front side of the wafer, and finally flipping the wafer by a wafer flipping device;

[0011] S5, removing the first carrier, selecting at least two points on the edge of the wafer obtained in step S4 for SOG coating and positioning, and then baking the wafer using a constant temperature drying device to evaporate the water film between the wafer and the first carrier, and the water film between the wafer and the second carrier, and then removing the first carrier upwards using a semi-automatic device, and finally sealing the edge of the wafer using a spin coating medium SOG, completing the SOG coating on the edge of the wafer to form a comprehensive edge sealing;

[0012] S6. Transport the wafer obtained in step S5 to the next step for processing.

[0013] Preferably, in step S1, the back side of the wafer is thinned by grinding / etching, and the wafer is cleaned and dried after the thinning is completed.

[0014] Preferably, in steps S3 and S4, an exhaust device is used to exhaust air from the outside of the first carrier, and the first carrier and the wafer are adsorbed through the air holes on the first carrier to avoid the position of the wafer on the first carrier from shifting during the wafer flipping and the removal of the grinding tape.

[0015] Preferably, in step S4, when the semi-automatic equipment removes the grinding tape upward, it first lifts up one side of the grinding tape, and then pulls the lifted side upward to gradually remove the grinding tape from the wafer.

[0016] Preferably, when selecting at least two points on the edge of the wafer obtained in step S4 for SOG coating limitation, the selected multiple points are distributed on the edge of the wafer, and there are gaps between the points to facilitate the volatilization of the water film in step S5, thereby realizing the positioning of the wafer from different points.

[0017] In step S5, when the SOG coating is limited and the edge of the wafer is sealed by using the spin coating medium SOG, the SOG is coated on the edge of the wafer and above the second carrier, and the SOG coating does not contact the first carrier.

[0018] Preferably, the step S4 can also spray deionized water on the second carrier to form a water film with uniform thickness, and then adhere the front side of the wafer obtained in step S3 to the second carrier through the water film on the second carrier. In the process of adhering the front side of the wafer to the second carrier through the water film, the exhaust device extracts air from the outside of the first carrier to achieve adsorption of the first carrier and the wafer to avoid displacement between the wafer and the first carrier.

[0019] Preferably, in step S5, at least two points of the wafer edge obtained in step S4 are selected for SOG coating and positioning, and then the wafer is baked by a constant temperature drying device, so that the water film between the wafer and the first carrier plate evaporates, and the water film between the wafer and the second carrier plate evaporates, and then the edge of the wafer is sealed by a spin coating medium SOG, so as to complete the SOG coating positioning of the wafer edge, and finally the first carrier plate is removed upward by a semi-automatic device;

[0020] Preferably, in step S5, the blocking material used may also be polyimide.

[0021] Beneficial effects of the present invention:

[0022] During the process of grinding and thinning the wafer, a grinding tape with UV glue is used to carry the wafer to provide protection for the wafer, thereby preventing the front side of the wafer from being damaged during the grinding and thinning process. The wafer is adsorbed by a first carrier with through holes in cooperation with an exhaust device to facilitate the transfer and flipping of the wafer. The wafer is then bonded to the second carrier by coating SOG and a water film to facilitate wafer positioning and avoid position deviation between the wafer and the second carrier. The water film is then evaporated by constant temperature drying, so that there is no need to use colloid bonding between the wafer and the second carrier, and the wafer and the second carrier can be fully bonded. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 is a process flow chart of step S1 in Example 1 of the present invention;

[0025] Figure 2 is a process flow chart of step S2 in Example 1 of the present invention;

[0026] Figure 3 is a process flow chart of step S3 in Example 1 of the present invention;

[0027] Figure 4 is a process flow chart of step S4 in Example 1 of the present invention;

[0028] Figure 5 is a process flow chart of step S5 in Example 1 of the present invention;

[0029] Figure 6 yes Figure 5The process flow chart of coating the edge of the wafer with SOG to form a full edge blocking portion in step S5 is shown;

[0030] Figure 7 is a process flow chart of step S4 in Example 2 of the present invention;

[0031] Figure 8 It is a process flow chart of step S5 in Example 3 of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Example 1

[0034] A method for attaching a wafer to a glass carrier comprises the following steps:

[0035] S1, wafer thinning, the front side of the wafer that has completed the first half of the front side process is attached to the grinding tape with UV glue, so that the back side of the wafer faces upward, and then the back side of the wafer is thinned by automated equipment;

[0036] S2, attaching the first carrier, spraying deionized water onto the first carrier to form a water film of uniform thickness on the first carrier, then flipping the wafer obtained in step S1 through a flipping device, and then attaching the back side of the wafer to the first carrier through the water film;

[0037] S3, removing the grinding tape, irradiating the wafer with UV light of a specific wavelength to weaken the UV adhesive on the grinding tape, and finally removing the grinding tape upwards with a semi-automatic device;

[0038] S4, attaching the second carrier, spraying deionized water on the front side of the wafer obtained in step S3 to form a water film with uniform thickness, and then attaching the second carrier to the front side of the wafer through the water film on the front side of the wafer, and finally flipping the wafer by a wafer flipping device;

[0039] S5, removing the first carrier, selecting at least two points on the edge of the wafer obtained in step S4 for SOG coating and positioning, and then baking the wafer using a constant temperature drying device to evaporate the water film between the wafer and the first carrier, and the water film between the wafer and the second carrier, and then removing the first carrier upwards using a semi-automatic device, and finally sealing the edge of the wafer using a spin coating medium SOG, completing the SOG coating on the edge of the wafer to form a comprehensive edge sealing;

[0040] S6. Transport the wafer obtained in step S5 to the next step for processing.

[0041] Example 2

[0042] A method for attaching a wafer to a glass carrier comprises the following steps:

[0043] S1, wafer thinning, the front side of the wafer that has completed the first half of the front side process is attached to the grinding tape with UV glue, so that the back side of the wafer faces upward, and then the back side of the wafer is thinned by automated equipment;

[0044] S2, attaching the first carrier, spraying deionized water onto the first carrier to form a water film of uniform thickness on the first carrier, then flipping the wafer obtained in step S1 through a flipping device, and then attaching the back side of the wafer to the first carrier through the water film;

[0045] S3, removing the grinding tape, irradiating the wafer with UV light of a specific wavelength to weaken the UV adhesive on the grinding tape, and finally removing the grinding tape upwards with a semi-automatic device;

[0046] S4, attaching a second carrier, spraying deionized water on the second carrier to form a water film with uniform thickness, and then attaching the front side of the wafer obtained in step S3 to the second carrier through the water film on the second carrier;

[0047] S5, removing the first carrier, selecting at least two points on the edge of the wafer obtained in step S4 for SOG coating and positioning, and then baking the wafer using a constant temperature drying device to evaporate the water film between the wafer and the first carrier, and the water film between the wafer and the second carrier, and then removing the first carrier upwards using a semi-automatic device, and finally sealing the edge of the wafer with a spin-coated medium SOG to complete SOG coating on the edge of the wafer to form a comprehensive edge sealing;

[0048] S6. Transport the wafer obtained in step S5 to the next step for processing.

[0049] Example 3

[0050] A method for attaching a wafer to a glass carrier comprises the following steps:

[0051] S1, wafer thinning, the front side of the wafer that has completed the first half of the front side process is attached to the grinding tape with UV glue, so that the back side of the wafer faces upward, and then the back side of the wafer is thinned by automated equipment;

[0052] S2, attaching the first carrier, spraying deionized water onto the first carrier to form a water film of uniform thickness on the first carrier, then flipping the wafer obtained in step S1 through a flipping device, and then attaching the back side of the wafer to the first carrier through the water film;

[0053] S3, removing the grinding tape, irradiating the wafer with UV light of a specific wavelength to weaken the UV adhesive on the grinding tape, and finally removing the grinding tape upwards with a semi-automatic device;

[0054] S4, attaching the second carrier, spraying deionized water on the front side of the wafer obtained in step S3 to form a water film with uniform thickness, and then attaching the second carrier to the front side of the wafer through the water film on the front side of the wafer, and finally flipping the wafer by a wafer flipping device;

[0055] S5, removing the first carrier, selecting at least two points on the edge of the wafer obtained in step S4 for SOG coating and positioning, and then baking the wafer using a constant temperature drying device to evaporate the water film between the wafer and the first carrier, and the water film between the wafer and the second carrier, and then sealing the edge of the wafer using a spin coating medium SOG, completing the SOG coating on the edge of the wafer to form a comprehensive edge sealing, and finally removing the first carrier upwards using a semi-automatic device;

[0056] S6. Transport the wafer obtained in step S5 to the next step for processing.

[0057] Compared with the related art, the wafer and glass carrier attachment method provided by the present invention has the following beneficial effects:

[0058] During the process of grinding and thinning the wafer, a grinding tape with UV glue is used to carry the wafer to provide protection for the wafer, thereby preventing the front side of the wafer from being damaged during the grinding and thinning process. The wafer is adsorbed by a first carrier with through holes in cooperation with an exhaust device to facilitate the transfer and flipping of the wafer. The wafer is then bonded to the second carrier by coating SOG and a water film to facilitate wafer positioning and avoid position deviation between the wafer and the second carrier. The water film is then evaporated by constant temperature drying, so that there is no need to use colloid bonding between the wafer and the second carrier, and the wafer and the second carrier can be fully bonded.

[0059] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A method for attaching a wafer to a glass carrier, characterized in that: The following steps are involved: S1, wafer thinning, the front side of the wafer that has completed the first half of the front side process is attached to the grinding tape with UV glue, so that the back side of the wafer faces upward, and then the back side of the wafer is thinned by automated equipment; S2, attaching the first carrier, spraying deionized water onto the first carrier to form a water film of uniform thickness on the first carrier, then flipping the wafer obtained in step S1 through a flipping device, and then attaching the back side of the wafer to the first carrier through the water film; S3, removing the grinding tape, irradiating the wafer with UV light of a specific wavelength to weaken the UV adhesive on the grinding tape, and finally removing the grinding tape upwards with a semi-automatic device; S4, attaching the second carrier, spraying deionized water on the front side of the wafer obtained in step S3 to form a water film with uniform thickness, and then attaching the second carrier to the front side of the wafer through the water film on the front side of the wafer, and finally flipping the wafer by a wafer flipping device; S5, removing the first carrier, selecting at least two points on the edge of the wafer obtained in step S4 for SOG coating and positioning, and then baking the wafer using a constant temperature drying device to evaporate the water film between the wafer and the first carrier, and the water film between the wafer and the second carrier, and then removing the first carrier upwards using a semi-automatic device, and finally sealing the edge of the wafer using a spin coating medium SOG, completing the SOG coating on the edge of the wafer to form a comprehensive edge sealing; S6, transporting the wafer obtained in step S5 to the next step for processing; In steps S3 and S4, an exhaust device is used to exhaust air from the other side of the first carrier, and the first carrier and the wafer are adsorbed through the air holes on the first carrier to avoid the position of the wafer on the first carrier from shifting during the wafer flipping and the removal of the grinding tape.

2. The method for attaching a wafer to a glass carrier according to claim 1, characterized in that: In step S1, the back side of the wafer is thinned by grinding / etching, and the wafer is cleaned and dried after the thinning is completed.

3. The method for attaching a wafer to a glass carrier according to claim 1, characterized in that: In step S4, when the semi-automatic equipment removes the grinding tape upward, it first lifts up one side of the grinding tape, and then pulls the lifted side upward to gradually remove the grinding tape from the wafer.

4. The method for attaching a wafer to a glass carrier according to claim 1, characterized in that: When selecting at least two points on the edge of the wafer obtained in step S4 for SOG coating positioning, the selected multiple points are distributed on the edge of the wafer, and there are gaps between the points to facilitate the volatilization of the water film in step S5 and realize the positioning of the wafer from different points.

5. The method for attaching a wafer to a glass carrier according to claim 4, characterized in that: In step S5, when the SOG coating is limited and the edge of the wafer is sealed by using the spin coating medium SOG, the SOG is coated on the edge of the wafer and above the second carrier, and the SOG coating does not contact the first carrier.

6. The method for attaching a wafer to a glass carrier according to claim 1, characterized in that: The step S4 includes spraying deionized water on the second carrier to form a water film with uniform thickness, and then bonding the front side of the wafer obtained in step S3 to the second carrier through the water film on the second carrier. In the process of bonding the front side of the wafer to the second carrier through the water film, an exhaust device performs exhaust from the other side of the first carrier to achieve adsorption of the first carrier and the wafer to avoid displacement between the wafer and the first carrier.

7. The method for attaching a wafer to a glass carrier according to claim 1, characterized in that: The step S5 includes selecting at least two points on the edge of the wafer obtained in the step S4 for SOG coating and limiting, and then using a constant temperature drying device to bake the wafer so that the water film between the wafer and the first carrier evaporates, and the water film between the wafer and the second carrier evaporates, and then using a rotary coating medium SOG to seal the edge of the wafer to complete the SOG coating and limiting the edge of the wafer, and finally using a semi-automatic device to remove the first carrier upwards.

8. The method for attaching a wafer to a glass carrier according to claim 1, characterized in that: In the step S5, the blocking material used is polyimide.

Images