JPS609661B2 - Manufacturing method of semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a semiconductor device in which a plurality of semiconductor pellets are punched out from a semiconductor wafer having a PN junction.

Conventionally, when manufacturing multiple semiconductor devices from a single semiconductor wafer, the semiconductor wafer is punched and extracted to obtain multiple semiconductor pellets, and then electrode metal is brazed to each semiconductor pellet. was manufacturing.

A conventional method of manufacturing a semiconductor device will be explained with reference to FIGS. 1 to 5.

FIG. 1 is a plan view of a semiconductor wafer 1, which is made by selectively diffusing a semiconductor substrate by photo-etching or the like, and has one or more PN junctions. FIG. 2 is also a plan view of the semiconductor wafer 1, but shows the pellet portion 2a on the surface of the semiconductor wafer 1 to be extracted. Figure 3 shows semiconductor pellet 2
Fig. 4 is a plan view thereof, and Fig. 4 is a side view thereof. This semiconductor pellet 2 is made by applying ultrasonic waves to the pellet portion 2a of the semiconductor wafer 1.
It is obtained by punching or extracting with a scriber, a scriber, etc. Electrode metal is then attached to the semiconductor pellets 2 separated from the semiconductor wafer 1 in this manner to manufacture semiconductor devices. FIG. 5 is a side view of this semiconductor device. An electrode metal 4 made of molybdenum, tungsten, or the like is brazed to the lower surface of the semiconductor pellet 2 via a brazing material 5 made of aluminum, aluminum silicon, or the like. In such conventional semiconductor device manufacturing methods, the number of manufacturing steps is long because the semiconductor wafer is punched out and electrode metal is brazed one by one to the extracted semiconductor pellets. There is a drawback that the semiconductor pellet is easily cracked, resulting in a lower manufacturing yield and poor productivity.

Furthermore, if the semiconductor pellet becomes easily breakable, there is a problem in that its properties deteriorate after it is mounted on a semiconductor device. The present invention was made to eliminate these conventional drawbacks, and its purpose is to provide a method for manufacturing a semiconductor device that has good productivity and eliminates characteristic deterioration.

In order to achieve such an object, the present invention is such that an electrode metal is attached to a semiconductor wafer via a brazing material, and then a semiconductor pellet is punched out from the semiconductor wafer.

Hereinafter, this invention will be explained in detail based on examples with reference to FIGS. 6 to 10. In addition, in each figure, Figure 1~
The same or corresponding parts as in FIG. 5 are given the same reference numerals. FIG. 6 shows a plan view of a semiconductor wafer 1 used in an embodiment of the method for manufacturing a semiconductor device according to the present invention.

This semiconductor wafer 1 is made by selectively diffusing a semiconductor substrate in which positioning grooves 3 have been formed using a photo-etching method to form one or more PN junctions. Next, as shown in the side view of FIG. 7, a plurality of (four in this example) electrode metals 4 made of materials such as molybdenum or tungsten are connected through a disc brazing material 5. It is provided on the lower surface of the semiconductor wafer 1 and assembled before brazing, and then the temperature is raised to melt the brazing material 5 and the semiconductor wafer and the electrode metal 4 are joined by brazing. Next, the semiconductor wafer 1 is punched out. FIG. 8 is a plan view of the semiconductor wafer 1 during punching, and FIG. 9 is a side view thereof. The pellet portion 2a of the semiconductor wafer 1 is an electrode metal 4
It is formed in the same circular shape. Therefore, when the pellet portion 2a is punched out by a punching method using ultrasonic waves, a scraper, a laser, etc., it is separated from the semiconductor wafer 1 and taken out with the semiconductor pellet 2 and the electrode metal 4 brazed with the brazing material 5. can be released. FIG. 10 is a side view of the semiconductor device taken out in this manner. In this embodiment, four semiconductor devices can be taken out from one semiconductor wafer. This number is arbitrarily set depending on the size of the semiconductor wafer and the size of the semiconductor device to be taken out.
In the above embodiments, the diameter of the semiconductor pellet was punched out to be the same as the diameter of the electrode metal, but it may be larger or smaller than this. Furthermore, in the above embodiments, a plurality of electrode metals having a diameter considerably smaller than the diameter of the semiconductor wafer were used;
It is also possible to bond electrode metals with approximately the same diameter as the semiconductor wafer using a brazing material, and then simultaneously punch out the semiconductor wafer and the electrode metal to a desired size to take out a plurality of semiconductor devices.

Furthermore, the shape of the semiconductor pellet when cut out is circular, as well as
It can be any shape such as an ellipse or polygon.

As described above, according to the method for manufacturing a semiconductor device according to the present invention, the semiconductor pellet is removed after the electrode metal is brazed to the semiconductor wafer via the brazing material, which reduces the number of manufacturing steps and This eliminates the problem of semiconductor pellets cracking and lower manufacturing yields, and also eliminates the problem of lower manufacturing yields when vertically mounted on semiconductor devices, improving productivity, reducing costs, and stabilizing quality. This has the effect of increasing reliability.

[Brief explanation of drawings]

1 and 2 are a plan view of a semiconductor wafer used in a conventional manufacturing method, FIG. 3 is a plan view of a semiconductor pellet, FIG. 4 is a side view thereof, and FIG. 5 is a side view of a semiconductor device. FIG. 6 is a plan view of a semiconductor wafer used in an embodiment of the semiconductor device manufacturing method according to the present invention, FIG. 7 is a side view of the semiconductor wafer during brazing, and FIG. 8 is a side view of the semiconductor wafer during extraction. FIG. 9 is a plan view, FIG. 9 is a side view thereof, and FIG. 10 is a side view of the semiconductor device. In each figure, the same or corresponding parts are given the same reference numerals. 1... Semiconductor wafer, 2...
Semiconductor pellet, 2a... Beret part, 3.
... Groove, 4... Electrode metal, 5... Brazing metal. Ice 1 Ousa 2 Figures O 3 Figures 4 Figures 5 Figures 6 Figures O? Figure 8 Figure 9 Figure 10

Claims (1)

[Claims] 1. A method for manufacturing a semiconductor device in which a plurality of semiconductor pellets are punched and extracted from a semiconductor wafer having a PN junction, wherein an electrode metal is brazed to the semiconductor wafer through a brazing material, and then semiconductor pellets are punched from the semiconductor wafer. , a method for manufacturing a semiconductor device, characterized in that the semiconductor device is extracted.