TW200941568A - Method for wafer cutting - Google Patents

Abstract

A method for wafer cutting includes: providing a wafer having a top surface and a bottom surface; forming a protecting layer on the top surface of the wafer; forming a plurality of cutting trenches on the top surface of the wafer to define a plurality of dies; arranging a BG tape covering the protecting layer; polishing the bottom surface of the wafer to expose the inside of those cutting trenches; arranging a die-attach-film covering the bottom surface of the wafer, wherein the die-attach-film is composed of a adhesive film and a liner film and the adhesive film is contacting with the bottom surface of the wafer; removing the BG tape, wherein a portion of the adhesive layer is exposed at the bottom of those cutting trenches; removing the exposed adhesive layer to expose the liner film; removing the protecting layer; and obtaining those dies.

Description

200941568 IX. Description of the Invention: [Technical Field] The present invention relates to a semiconductor packaging technology, and more particularly to a wafer cutting method. [Prior Art] A conventional wafer level package is to cut a die onto a wafer and then package it. The die attache film (DAF) used in the current packaging process is separated as the wafer is diced. When the wafer is cut, it is easy to cause solder bump contamination due to the burr issue, which affects the yield of the product. SUMMARY OF THE INVENTION In order to solve the above problems, one of the objects of the present invention is to provide a wafer dicing method for performing a grain dicing step before wafer polishing, so that the crystal grains are separated but the die adhesion film remains intact. It can effectively avoid the burr phenomenon and cause contamination of the pad. The method of the present invention includes the steps of protecting the wafer on the wafer, wherein the wafer has a front side and a back side; forming an exposed recessed groove interior; _ ' Grinding day a round back to the grain attached film is made of - adhesive film and 1 placed away from the back of the wafer, which makes the back of the wafer contact; remove the back grinding glue · and 'adhesive system And the bottom of the crystal groove; the exposed portion is exposed to the cut, the portion of the adhesive film is exposed to the cutting protective layer; and the layer of the ns & portion is exposed and the release layer is exposed: removal 5 200941568 [Embodiment] 1A, FIG. 1B, FIG. 1C, FIG. 1D, FIG. 1E, FIG. 1B, FIG. 1 and FIG. 1 are schematic diagrams showing the flow of a wafer cutting method according to an embodiment of the present invention. In the present embodiment, the wafer dicing method includes the following (4). First, referring to FIG. 1A, a wafer 1 is provided. This wafer 1〇 i back ❹

surface. Next, a protective layer 2 is formed on the front side of the wafer 1 . The method of forming the protective layer 20 is carried out by means of a coating such as spin coating, and the hard baked layer 2 is baked. This layer 2 () is made of polyimine, - oxidized ground (SK32) or nitrogen cut (with 3) κ edge material. After π π 5, as shown in FIG. 1B, a plurality of dicing is formed on the front side of the wafer 1 . The dicing groove 12 has a special degree and does not penetrate the wafer and cuts Η丄 a plurality of crystals 14 are generalized. The cutting recess 12 can be formed by etching, mechanical cutting or laser cutting. , = The above description '凊 Attached to Figure 1C' - the back grinding tape 30 (BG tape) is overlaid on the protective layer 2〇, this ^ ψ Γ f grinding the knee band 3G system, used to protect the front side of the wafer Not contaminated or damaged during the grinding process. Thereafter, as shown in FIG. 1D, the back surface of the wafer K) is ground to expose the inside of the cut groove 412 (Fig. DAF) ® 1E} 4 〇 (〇ie ^ 42 and a release type: 44, the back side. The grain adhesion 臈40 is a combination of an adhesive film and an eaSmg), and the adhesive film is in contact with the back side of the Japanese yen.邾 There is a film W system and 曰曰 臈 暴 暴 ^ ' remove _ grinding tape 3 (3, part of the bottom of the bottom, ° groove 12 bottom. After that, remove the sticky exposed to the bottom of the cutting groove 12 The film 42 is exposed to the shape-cutting = groove removal step 42 (4), 隹~ττ Figure 1G and the figure are not 'adhesively 臈42. In another 眚, & 卩 V exposure process and remove According to the reaction ' ', the order of removing the adhesive film 42 can be utilized - non-Rong & _ square _. Next, ..., _ (four) two = 6 200941568 layer 20. Finally, as shown in Figure 1J, the crystal is obtained The method of obtaining the crystal grains 14 further comprises removing the crystal grains 14 from the release film 44. In summary, the present invention completes the grain cutting step before the wafer is ground, so that the crystal grains are separated but The die-adhesive film remains intact, so that the burr phenomenon can be effectively prevented from causing pad contamination. The present invention can achieve the purpose of separating the die-adhesive film without damaging the die. The embodiments described above are merely illustrative of the technical idea of the present invention. And the purpose of which is to enable those skilled in the art to understand the contents of the present invention and It is to be understood that the scope of the invention is not limited thereto, that is, the equivalent changes or modifications made in accordance with the spirit of the invention should be included in the scope of the invention. 200941568 [Simple description]

1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, II, and 1J are schematic views showing an embodiment of the present invention. [Recognition of component symbols] 10 Wafer 12 Cutting groove 14 Grain 20 Protective layer 30 Back grinding tape 40 Grain adhesion film 42 Adhesive film 42, Reacted adhesive film 44 Release film 8

Claims (1)

200941568 • Patent application scope: 1. A wafer dicing method comprising the steps of: providing a wafer having a front side and a back side. Forming a protective layer on the front side of the wafer, ❹ Q ...' ~n' is called 竣儿回, forming a complex number (four) rib groove _ wafer red ridge "her die area attached a back abrasive tape over the protective layer; grinding the back side of the wafer to expose A plurality of die attaching films are disposed in the cutting recesses to cover the back surface of the wafer, and the third surface of the wafer is combined with the 'film combination' and the back grinding tape is removed. Part of the bottom of the adhesive groove; recorded in the cutting to remove the adhesive film exposed to the bottom of the cutting groove and remove the protective layer; and the Inna layer to obtain the crystal grains. The wafer dicing method according to Item 1, wherein the shape is formed by coating. The step of the X-protecting layer. The wafer cutting method according to claim 2, wherein the forming comprises a hard-backed dry wire. The protective layer. 'The method of wafer cutting method described in Item 1 In the case of the cut gold 丨 (4), the mechanical slamming laser _ the method of forming the 4 core groove system using the wafer cutting method described in claim 1, wherein the grinding and grinding wheel is mechanically ground. The wafer dicing method of item 1, wherein the step of removing the smashing step-domain; 2. 9 200941568 7. The wafer cutting method of claim 1, wherein the removal is exposed to the bottom of the cutting grooves The step of adhering the film is to remove the adhesive film by an anisotropic etching method. The wafer cutting method according to claim 1, wherein the step of obtaining the crystal grains further comprises: Remove from the release film.