TW202322417A - Wafer thinning and transfer method for light-emitting diode and product thereof capable of avoiding wafer warping or breakage due to thinning - Google Patents

Abstract

A wafer thinning and transfer method for light-emitting diodes includes the following steps: bonding a wafer to a first supporting sheet with solid wax, and then performing thinning operation on a first surface of the wafer; applying a high-temperature adhesive onto the first surface of the thinned wafer and covering and bpnding a second supporting sheet thereon to allow the wafer to be placed between the two supporting sheets; and separating the first supporting sheet at high temperature, keeping the wafer on the second supporting sheet, and supporting the thinned wafer through the second supporting sheet to avoid breakage.

Description

Wafer thinning and transfer method for light-emitting diodes and products thereof

The invention relates to a wafer thinning and transfer method for light-emitting diodes and its products, especially to a wafer that is supported through the setting of a support sheet, which can effectively prevent wafers from being broken due to warping after thinning or other reasons , but it is impossible to make the wafer completely enter the back-end, so as to improve the yield of the wafer after thinning.

Nowadays, integrated circuit components are used in many electronic products, which have the advantages of small size and powerful functions. Wafers used to make integrated circuit components need to go through a grinding and thinning process in the manufacturing process to reduce the surface thickness of the wafer and make it flat. Cutting, packaging and other operations.

However, the commonly used grinding methods have always had problems such as high fragmentation rate, low yield, high cost, and low efficiency. On the traditional heating table, the method of using acetone and alcohol to remove wax has always had the problems of high fragmentation rate and low yield.

The most important process affecting the yield rate is the cracks that occur during grinding and waxing. Therefore, how to improve the process of grinding and waxing to reduce the cracking rate, improve the yield rate and production efficiency is an urgent need. problem to overcome.

It should be noted that one of the key points for manufacturers to make profits is to improve efficiency and output, so as to reduce costs and create profits.

It can be seen that the above-mentioned wafer thinning method for conventional light-emitting diodes has many deficiencies, is not a good designer, and needs to be improved urgently.

In view of the shortcomings derived from the above-mentioned methods of wafer thinning for light-emitting diodes, the inventor of this case wanted to improve and innovate. After years of painstaking research, he finally successfully developed and completed the light-emitting diode wafer. Thinning and reposting method and products thereof.

Embodiments of the present invention provide a wafer thinning and transfer method for light-emitting diodes and its products, which can fix the wafer on the support sheet, avoid warping and fragmentation of the wafer after thinning, and improve the yield rate.

In order to achieve the above object, the wafer thinning and transfer method of the light-emitting diode of the present invention, its steps include: sticking a single wafer on a first supporting sheet with solid wax, and then performing thinning on the first surface of the wafer. Thin operation: apply high-temperature glue on the first surface of the wafer after thinning, and cover and paste a second support sheet, so that the wafer is placed between the two support sheets; separate the first support sheet at high temperature, and keep the wafer On the second supporting sheet, the thinned wafer is supported by the second supporting sheet to avoid fragmentation.

Wherein the material of the first supporting sheet is sapphire, and the material of the second supporting sheet is sapphire or adhesive tape, and the better method of separating the first supporting sheet is to use the separation temperature difference between high-temperature glue and low-temperature wax to separate.

The present invention also provides a product obtained by the wafer thinning and transfer method for light-emitting diodes as described above, and the product is characterized by: .

To sum up, the products obtained by the wafer thinning and transfer method for light-emitting diodes provided by the embodiments of the present invention are such that the wafer is supported by a support sheet before and after thinning, which can Ensure that the wafer does not warp and break due to external force.

The detailed features and advantages of the present invention are described in detail below in the implementation mode, and its content is enough to make any person familiar with the related art understand the technical content of the present invention and implement it accordingly, and according to the content disclosed in this specification, the scope of the patent application and the drawings , anyone skilled in the relevant arts can easily understand the purpose and advantages of the present invention.

1: Wafer

2: solid wax

3: The first support piece

4: High temperature glue

5: The second support piece

The first figure is a schematic flow chart of the steps of the wafer thinning and transfer method for light-emitting diodes of the present invention.

The second figure is a schematic diagram of the first operation flow of the light-emitting diode wafer thinning and transfer method of the present invention.

The third figure is a schematic diagram of the second operation flow of the light-emitting diode wafer thinning transfer method of the present invention.

In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments are listed below and described in detail in conjunction with the accompanying drawings.

Please refer to Figure 1 and Figure 2, which are schematic flow charts of steps and a schematic flow chart of the method for thinning and pasting wafers of light-emitting diodes of the present invention and a schematic flow chart of the first operation. The implementation steps are roughly as follows.

It should be noted that the following steps are the main implementation spirit of this embodiment, but the actual implementation method is not limited to the following specific implementation forms. In other words, on the basis of this embodiment, those skilled in the art can also replace the implementation of the following steps with other equivalent implementations.

Step S01: Attaching the single wafer 1 to a first supporting sheet 3 with solid wax 2 Next, the first surface of the wafer 1 is thinned.

More specifically, in this embodiment, the first supporting sheet 3 is made of sapphire, and the total thickness variation (TTV)≦3um. The thinned thickness of the wafer 1 is generally reduced to less than 80um.

In this step S01, the thinning method of the wafer 1 can be grinding, copper polishing or soft polishing, but not limited to the above methods, and in the thinning operation, the wafer is set on the carrier plate, and the wafer is connected to the carrier plate The room is processed by adsorption and fixation in a pseudo-vacuum mode.

Step S02: Apply high-temperature glue 4 on the first surface of the thinned wafer 1, and cover and attach a second supporting sheet 5, so that the wafer 1 is placed between the two supporting sheets.

More specifically, in this embodiment, the second supporting sheet 5 is made of sapphire, and the total thickness variation (TTV)≦3um. When the second supporting piece is attached to the wafer 1 , the second supporting piece 5 can be lightly pressed to ensure that the second supporting piece 5 is fixed on the wafer 1 .

Step S03 : separating the first supporting sheet 3 at high temperature, keeping the wafer 1 on the second supporting sheet 5 , and supporting the thinned wafer 1 through the second supporting sheet 5 to avoid fragmentation.

In this step S03 , the separation high temperature system utilizes the separation temperature difference between the high-temperature glue and the low-temperature wax to separate one side while the other side is still sticky.

Through the above steps, it can be seen that the wafer 1 is supported by the supporting sheet from before to after the thinning operation, which can prevent the warping and fragmentation of the wafer 1 due to various external factors, and greatly improve the existing wafer without any support. High defect rate caused by waxing process.

Please refer to the third figure, which is a schematic diagram of the second operation flow of the wafer thinning and transfer method for light-emitting diodes of the present invention. In this embodiment, the general steps are the same as the above-mentioned implementation steps. The only difference is that The material of this second support piece 5 is adhesive tape paster, through adhesive tape straight It is bonded to the first surface of the wafer 1 to achieve the effect of fixing and supporting the wafer. The follow-up process is the same as the above-mentioned implementation steps. The first support sheet 3 is separated through high temperature, so that the wafer 1 is retained on the second support sheet 5 to support the wafer 1 and avoid warping and fragmentation of the wafer.

Incidentally, the products manufactured through the wafer thinning and transfer method of light-emitting diodes have the following technical features in terms of structure. Before and after the wafer 1 is thinned, at least one surface of the wafer 1 is attached with a supporting sheet for support, which can effectively prevent the wafer 1 from warping and breaking.

The above detailed description is a specific description of a feasible embodiment of the present invention, but this embodiment is not used to limit the patent scope of the present invention, and any equivalent implementation or change that does not depart from the technical spirit of the present invention shall be included in In the patent scope of this case. The scope of protection of the rights of the present invention should be described in the scope of patent application described later.

Claims (9)

A wafer thinning and transfer method for light-emitting diodes, the steps of which include: Attach a single wafer to a first supporting sheet with solid wax, and then perform thinning operations on the first side of the wafer; apply high-temperature glue on the first side of the thinned wafer, and cover and paste a first Two supporting sheets, so that the wafer is placed between the two supporting sheets; the first supporting sheet is separated by high temperature, so that the wafer remains on the second supporting sheet, and the thinned wafer is supported by the second supporting sheet to avoid fragmentation. The wafer thinning and transfer method for light-emitting diodes described in item 1 of the scope of the patent application, wherein the first supporting sheet is made of sapphire, and the total thickness variation value (TTV)≦3um. The wafer thinning and transfer method for light-emitting diodes described in item 1 of the scope of the patent application, wherein the thinning thickness of the wafer is generally reduced to less than 80um. The wafer thinning and transfer method for light-emitting diodes described in item 1 of the scope of the patent application, wherein the second support sheet is made of sapphire, and the total thickness variation value (TTV)≦3um. According to the wafer thinning and transfer method for light-emitting diodes described in item 1 of the scope of the patent application, the second supporting sheet is made of adhesive tape. The wafer thinning and transfer method for light-emitting diodes as described in item 1 of the scope of patent application, wherein the high-temperature separation uses the temperature difference between the high-temperature glue and the solid wax to separate, so that one side is separated while the other side remains sticky Wafer thinning and transfer method for light-emitting diodes as described in item 1 of the scope of the patent application, wherein the wafer thinning method is grinding or copper polishing or soft polishing. Wafer thinning and transfer method for light-emitting diodes as described in item 1 of the scope of patent application, wherein in the thinning operation, the wafer is placed on the carrier plate, and there is a false vacuum between the carrier plate and the wafer The method is adsorbed and fixed for processing. A product manufactured by the light-emitting diode wafer thinning and transfer method described in item 1 of the scope of the patent application.

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