JPH02298036A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the rear of a wafer from being plated and to prevent a crack during a grinding operation of the rear by a method wherein, before a plating operation is executed at a bump formation operation, a resin film is formed in a peripheral part of the wafer. CONSTITUTION:A wafer 1 is sucked to a spinner 2 and rotated to coat its peripheral part with a resin such as a photoresist, a electron beam resist or the like by using a brush squeezing the resin from a side face of the wafer 1. A resin film 3' is thus formed. During a posterior process, a bump is formed by a plating method of a jet stream system. The water 1 is placed on a claw 7 at the tip of a tube 6 in such a way that its surface is faced downward, and a plating liquid 8 is blown off from the upper part and is sprayed onto the surface of the wafer 1. However, it is possible to prevent the rear and the side face of the wafer 1 from being sprayed by the plating liquid 8 thanks to the resin film 3' formed at the peripheral part of the wafer 1. Then, the rear of the wafer is ground. Since the rear of the wafer is not plated, a grinding blade is not loaded and an incidence that the wafer is cracked is reduced remarkably.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device that includes a step of forming bumps on a semiconductor wafer and grinding the back surface.

[Conventional technology]

TAB is a method to increase the packaging density of LSI than before.
There is a (tape automated bonding) method, which includes a step of forming bumps on a semiconductor wafer (hereinafter simply referred to as a wafer) and a step of grinding the back surface.

[Problem to be solved by the invention]

In conventional semiconductor device manufacturing methods, gold and copper electrode metals wrap around the backside of the wafer during the plating process to form bumps, and are difficult to completely remove because they are soft even when scraped with a knife. However, during back grinding in the subsequent process, the grinding blade would become clogged with the remaining metal, resulting in occasional accidents resulting in cracked wafers. In addition, the more the back surface was ground (the larger the wafer diameter and the larger the amount of grinding), the higher the incidence of cracking was. In Figure 1, the relationship between the amount of grinding and the crack occurrence rate is shown by O.

(Means for Solving the Problems) A method for manufacturing a semiconductor device of the present invention includes a step of providing a plating mask for forming bumps on the surface of a semiconductor wafer, and a step of providing a plating mask for forming bumps on the surface of a semiconductor wafer, and a step of providing a plating mask for forming bumps on a surface of a semiconductor wafer. The method includes the steps of forming bumps by plating after applying resin to the peripheral portion, and grinding the back surface of the semiconductor wafer.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

A mask for forming bumps is formed by applying photoresist to the surface of a wafer in which active regions of semiconductor elements have been formed, exposing it to light in a predetermined pattern, and developing it.

Next, as shown in FIG. 2(a), the wafer 1 with a diameter of 5 inches is attracted to the spinner 2 and rotated.
A resin such as photoresist or electron beam resin is applied from the side surface of the wafer by a brush 4 that exudes it to about 5 cm around the wafer to form a resin film 3' having a thickness of 5 to 6 μm. Alternatively, as shown in FIG. 2(b), move the spinner 2 holding the wafer 1 under vacuum at an angle of 90° so that the wafer 1 is vertical.
After rotation, the wafer 1 is placed in a tray 5 containing resin 3. It may be applied by rotating the spinner 2 so that the peripheral area is submerged by about 5 cm.

In the post-process, bumps are formed by a jet plating method, as shown in FIG. 3(a). The wafer 1 is placed face down on the claw 7 at the tip of the tube 6, and the plating solution 8 is blown out from below and the wafer 1. However, the resin film 3' formed around the periphery of the wafer 1 prevents the plating solution 8 from splashing onto the back and side surfaces of the wafer 1. Alternatively, as shown in FIG. 3(b), a dip plating method may be used, in which the wafer 1 is vacuum-adsorbed on a suction plate 9 and immersed in the plating solution 8. Since the wafer 1 is in close contact with the wafer 1, the back and side surfaces of the wafer 1 are not plated.

Next, the back side of the wafer is ground (the amount of grinding is 400 μm). Since the back side of the wafer is not plated, there is no clogging of the grinding blade, and as shown by the X mark in Figure 1, the incidence of wafer cracking is significantly reduced. It becomes less.

In addition, before applying the plating mask forming glue,
First, the entire back surface may be spin-coded with resin, and then only the front surface may be cleaned with a solvent on a spinner to mask the back surface. In this case, not only the side surfaces but also the entire back surface of the wafer are covered with the resin film, which has the advantage that it is easy to prevent plating and can be done using existing equipment.

〔Effect of the invention〕

As explained above, the present invention has the effect of preventing plating on the back side of the wafer by forming a resin film around the wafer before plating when forming bumps, and preventing cracking during the back grinding process. There is.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a characteristic diagram showing the relationship between the wafer cracking rate and the amount of grinding. The circles indicate the conventional results and the X's indicate the results of the present invention. Fig. 2(a) shows a state in which the wafer is held horizontally and the resin is applied, Fig. 2(b) shows the state in which the wafer is held vertically and the resin is applied, and Fig. 3(a) shows the state in which the wafer is held vertically and the resin is applied. 3(a) is a diagram for explaining the jet plating method, and FIG. 3(b) is a diagram for explaining the dip plating method.

1... Wafer, 2... Spinner, 3... Resin,
3'...Resin film, 4...Brush, 5...Dish, 6...
・Cylinder, 7...Claw, 8...Plating solution.

Claims (1)

[Claims] a step of providing a plating mask for forming bumps on the surface of a semiconductor wafer; a step of applying a resin to a peripheral portion of the semiconductor wafer before or after forming the mask, and then forming bumps by a plating method; A method for manufacturing a semiconductor device, comprising the step of grinding a back surface of the semiconductor wafer.