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CN-113725069-B - Wafer film pasting process optimization method

CN113725069BCN 113725069 BCN113725069 BCN 113725069BCN-113725069-B

Abstract

The present invention discloses an optimization method for wafer film sticking process. The method designs experiments using DOE matrix design method on the parameter book involved in the wafer film sticking process. The experiments are conducted in the order of the experiments, and the optimized process parameters are the process parameters that can obtain the maximum lifespan. The process parameters obtained through this method can ensure that the cutting blade can be warned in advance before the lifespan reaches the node, and the safety margin ensures that the products already installed on the equipment can be safely processed and meet the process quality standards without defective products.

Inventors

  • LI XINGLI
  • MA MIANZHI
  • SHI ZHIYU
  • FENG HOUQING

Assignees

  • 华天科技（西安）有限公司

Dates

Publication Date
20260505
Application Date
20210827

Claims (8)

  1. 1. The wafer film pasting process optimizing method is characterized by comprising the following steps of: step 1, determining optimized technological parameters of a film pasting process of a wafer (1), wherein the technological parameters comprise a type of an adhesive (2), a type of a blade, a cutting speed, a cutting angle and a film cutting blade temperature; The selection of the type of the adhesive (2) is based on the parameters of the adhesive, wherein the parameters of the adhesive comprise structure, thickness precision, bonding strength and total thickness change of a wafer in the grinding process; step 2, designing a film sticking test process by a DOE matrix design method; step 3, performing a film sticking test according to the parameters of the DOE matrix design; When the film is stuck by any group of parameters, after the adhesive (2) is stuck on the circuit surface of the wafer (1) each time, the wafer (1) is repeatedly cut by the blade, so that the safety life of any group of cut wafers is obtained, wherein the safety life is that the wafer (1) is cut without defects when the blade cuts by any group of parameters, and the service life of the blade is maximized; the defect is that a residual film is arranged at the edge of the wafer or a film wrinkle (3) is arranged on the surface of the wafer; And 4, repeating the step 3, testing all groups of process parameters, and selecting the group with the largest safety life as the optimized process parameter.
  2. 2. The method of claim 1, wherein in step 1, the down-cut speed comprises 100mm/s, 150mm/s, 200mm/s, 250mm/s, and 300mm/s.
  3. 3. The method of claim 1, wherein in step 1, the down angle comprises 85 °, 90 ° and 95 °.
  4. 4. The method of claim 1, wherein in step 1, the dicing blade temperature comprises 120 ℃, 150 ℃, 170 ℃ and 200 ℃.
  5. 5. The method according to claim 1, wherein in step 4, the service life of the blade is determined according to the DOE test result.
  6. 6. The method according to any one of claims 1 to 5, wherein after step 4, the optimized process parameters are verified by a film pasting process and a thinning process.
  7. 7. The method of claim 6, wherein the verification items of the film lamination process include a film lamination appearance and a film lamination blade lifetime.
  8. 8. The method of claim 6, wherein the verification items of the thinning process include a grinding current value, a post-thinning thickness, a thinned total thickness, and roughness.

Description

Wafer film pasting process optimization method Technical Field The invention belongs to the technical field of packaging, and particularly relates to a wafer film pasting process optimization method. Background Wafer lapping is an indispensable technological process in the IC packaging process, and the wafer lapping is thinned through the lapping machine, and the wafer need carry out the pad pasting in the one side that the wafer had circuit structure before thinning or cutting, protection circuit structure, but if the pad pasting process goes wrong, the follow-up thinning or cutting process that easily makes and the lapping lobe of a leaf influences the encapsulation of product and product yield. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a wafer film pasting process optimization method so as to solve the problem of abrasive disc cracking caused by poor film pasting quality in the prior art. In order to achieve the purpose, the invention is realized by adopting the following technical scheme: the wafer film pasting process optimizing method comprises the following steps: Step 1, determining optimized technological parameters of a wafer film pasting process, wherein the technological parameters comprise a viscose model, a blade model, a cutter feeding speed, a cutter feeding angle and a film cutting blade temperature; step 2, designing a film sticking test process by a DOE matrix design method; step 3, performing a film sticking test according to the parameters of the DOE matrix design; When the film is stuck by any group of parameters, after the film is stuck on the circuit surface of the wafer each time, the blade repeatedly cuts the wafer to obtain the safety life of the group of cut wafers, wherein the safety life is that the cut wafer has no defect when the blade cuts by the group of parameters, and the service life of the blade is maximized; And 4, repeating the step 3, testing all groups of process parameters, and selecting the group with the largest safety life as the optimized process parameter. The invention further improves that: Preferably, in step1, the selection of the type of the adhesive is based on the parameters of the adhesive, including the structure, thickness accuracy, adhesion strength, and total thickness variation of the wafer during the polishing process. Preferably, in step 1, the cutter speeds include 100mm/s, 150mm/s, 200mm/s, 250mm/s and 300mm/s. Preferably, in step 1, the angle of the lower cutter includes 85 °, 90 ° and 95 °. Preferably, in step 1, the temperature of the film cutting blade includes 120 ℃, 150 ℃, 170 ℃ and 200 ℃. Preferably, in step 3, the defect is that a residual film is arranged at the edge of the wafer or a film wrinkle is arranged on the surface of the wafer. Preferably, in step 4, the service life of the blade is determined according to the DOE test result. Preferably, after the step 4, the optimized process parameters are verified through a film pasting process and a thinning process. Preferably, the verification items of the film attachment process include film attachment appearance and film attachment blade life. Preferably, the verification items of the thinning process include a grinding current value, a post-thinning thickness, a thinning total thickness, and roughness. Compared with the prior art, the invention has the following beneficial effects: The invention discloses a wafer film pasting process optimization method, which designs a test on a parameter book related to a wafer film pasting process through a DOE matrix design method, and tests according to the test sequence, wherein the process parameter with the maximum service life can be obtained as the optimized process parameter. The technological parameters obtained by the method can ensure that the film cutting blade can early warn in advance before the service life reaches a node, ensure the safety margin of the product on the equipment which is on machine, can be safely processed, accords with the technological quality standard, and has no defective products. Drawings FIG. 1 is a diagram of a film-bonding process according to the present invention; FIG. 2 is a schematic diagram of a defect with a residual film on a wafer edge according to the present invention; FIG. 3 is a schematic diagram of a defect of film wrinkling on a wafer surface according to the present invention; wherein, the wafer is 1-, the adhesive film is 2-and the film is 3-wrinkled Detailed Description In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," and the like are merely for convenience of description and to simplify the description of the present invention, but rather to indicate or imply that the apparatus or elements being referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be