JPH01256132A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To enable the manufacturing of a semiconductor device without using solder material chip, and improve workability, by forming an electrode layer composed of solder material, on the rear of a semiconductor element, and mounting it on a necessary part of a substrate by fusion bonding of the electrode layer. CONSTITUTION:A thin film 5 of eutectic solder material is formed on the whole rear of a semiconductor wafer 1, on one surface of which semiconductor elements 2,... are formed. The wafer are broken along scribe trenches, and each semiconductor element 2 is separated. The whole rear of the separated semiconductor element 2 is covered with a thin film of eutectic solder material, and this thin film turns to an electrode layer 3 of each semiconductor element 2. This semiconductor element 2 is so mounted at a specified position of the substrate 4 that the electrode layer 3 faces downward. By fusion bonding treatment like thermal compression bonding, the electrode layer 3 is melted, and the semiconductor element 2 and the substrate 4 are electrically connected. Thereby, a process to interpose a solder chip between the semiconductor element 2 and the substrate 4 is saved, so that the mounting process of semiconductor elements is simplified, and workability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention mainly relates to a method of manufacturing a high frequency semiconductor device, and more particularly to a method of mounting a semiconductor element on a substrate such as a ceramic substrate or a lead frame.

<Prior Art> A conventional method for manufacturing a semiconductor device will be described based on a method for manufacturing a high frequency semiconductor device shown in FIG.

Generally, the high-frequency semiconductor device 20 includes a semiconductor element 22 on which an electrode 21 is formed by vapor deposition of gold on the back surface of the substrate.
It is created by implementing it on top of 3. At this time, between the substrate 23 and the semiconductor element 22, Au-Si, Au-S
A eutectic brazing material chip 25 such as n is interposed, and the semiconductor element 22 is attached to the substrate 23 by welding the eutectic brazing material chip 25.
is fixed, and the electrode 21 of the semiconductor element 22 and the substrate 23 are electrically connected.

<Problems to be Solved by the Invention> By the way, in the conventional manufacturing method of the high frequency semiconductor device 20, the eutectic brazing material chip 25 is used as described above to mount the semiconductor element 22 on the substrate 23. Since a step of accurately sandwiching the eutectic brazing material chip 25 between the semiconductor element 22 and the substrate 23 is required, the work becomes more complicated and the workability cannot be easily improved.

In addition, it is necessary to use a sufficiently large brazing material chip 25 to ensure the connection with the board, but if this brazing material chip 25 is large, as shown in FIG. This may cause the mounted semiconductor element 22 to be tilted, causing trouble in later wire bonding, or the brazing filler metal may protrude from the semiconductor element 22, causing a short circuit, thereby improving the reliability of the high frequency semiconductor device 20. It was a hindrance.

Furthermore, since a large amount of expensive brazing filler metal is used, there is also the problem that the material cost increases.

The present invention has been made in view of the above-mentioned problems, and includes:
It is an object of the present invention to make it possible to manufacture a semiconductor device without using a brazing material chip, thereby improving workability and increasing the reliability of the semiconductor device.

<Means for Solving the Problems> In order to achieve the above object, the present invention includes a step of forming an electrode layer made of a brazing material on the back surface of a semiconductor element, and a process of forming an electrode layer made of a brazing material on the back surface of a semiconductor element, and bonding the semiconductor element to a substrate by welding the electrode layer. The method is characterized in that it includes a step of mounting on a required portion of the device.

<Function> According to the above manufacturing method, since the brazing material is directly provided as an electrode layer on the back surface of the semiconductor element, the semiconductor element is simply placed in a fixed position on the substrate and a welding process such as thermocompression bonding is performed. This eliminates the need to use brazing filler metal chips as in the past.

<Example> Hereinafter, the present invention will be explained in detail based on the method of manufacturing a high frequency semiconductor device shown in FIGS. 1 to 3. In these figures, numeral 1 is a semiconductor wafer, 2 is a high frequency semiconductor element, 3 is an electrode layer of the semiconductor element 2, and 4 is a substrate.

First, as shown in FIG. 1, a semiconductor element 2,...
Semiconductor wafer formed with! A thin film 5 of a eutectic brazing material such as Au-5i or Au-Sn is formed on the entire back surface of the substrate by vacuum evaporation.

Next, as shown in FIG. 2, this wafer 1 is broken along the scribe grooves to separate each semiconductor element 2. The entire back surface of the separated semiconductor elements 2C is covered with a thin film of eutectic brazing material, and this thin film serves as the electrode layer 3 of each semiconductor element 2.

Then, this semiconductor element 2 is placed on a substrate 4 with the electrode layer 3 facing down.
The electrode layer 3 is placed on a predetermined position, and the electrode layer 3 is melted by a welding process such as thermocompression bonding.
, the semiconductor element 2 is fixed and the semiconductor element 2 and the substrate 4 are fixed.
to be electrically connected.

In the above embodiments, a eutectic brazing filler metal is used as the brazing filler metal, but other brazing filler metals may be used. In addition, in the example,
Although the brazing material is formed as a thin film electrode layer 3 on the back surface of the semiconductor element 2 by vacuum deposition, the brazing material may be formed as a thick film electrode layer on the back surface of the semiconductor element by printing.

In addition, although the above-mentioned embodiment describes a method for manufacturing a high-frequency semiconductor device, the present invention is not limited to this, and it goes without saying that a method for manufacturing a semiconductor device can also be implemented.

<Effects of the Invention> As described above, according to the method for manufacturing a semiconductor device of the present invention, since the brazing material is provided directly as an electrode layer on the back surface of the semiconductor element, there is no need to use a brazing material depth as in the conventional method. , a semiconductor element can be mounted on a substrate. Therefore, since there is no need to interpose the brazing material chip between the semiconductor element and the substrate, the process of mounting the semiconductor element can be simplified and work efficiency can be improved.

In addition, since the brazing material is provided in a film form over the entire back surface of the semiconductor element, a small but necessary amount of the brazing material is interposed between the element and the substrate, which prevents the semiconductor element from tilting as in the conventional method. It is possible to prevent the brazing filler metal from protruding, thereby eliminating inconveniences caused by this, and improving the reliability of the semiconductor device. Further, the amount of brazing filler metal used can be kept to a small amount, and material costs can be reduced.

[Brief explanation of the drawing]

1 to 3 show the manufacturing process of a high frequency semiconductor device according to an embodiment of the present invention, and FIGS. 1 and 2 are side views,
FIG. 3 is a perspective view. 4 and 5 relate to a conventional example, where FIG. 4 is a perspective view showing the manufacturing process of a high frequency semiconductor device, and FIG. 5 is a sectional view thereof. 2...Semiconductor element, 3...Electrode layer, 4...Substrate, Applicant Legal company Material manufacturing agent Patent attorney Oka 1) Kazuhide Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] (1) A semiconductor device characterized by comprising a step of forming an electrode layer made of a brazing material on the back surface of a semiconductor element, and a step of mounting the semiconductor element on a desired part of a substrate by welding the electrode layer. Production method.