JPH05144987A - Production of semiconductor device - Google Patents

Abstract

PURPOSE:To provide the production of a semiconductor device which accurately and surely connects electrically an semiconductor element, which stores an outer lead terminal by surely and firmly bonding it on the wiring conductor of an external electric circuit board, on the wiring conductor of the external electric circuit board. CONSTITUTION:A semiconductor device is provided with a semiconductor element 4 which is stored in a container 3 whose external surface is provided with an outer lead terminal 5 and the electrode of the semiconductor element 4 is electrically connected to the outer lead terminal 5. Then, the surface of the outer lead terminal 5 of the semiconductor device is coated with a metal layer 8 composed of tin, the outer lead terminal 5 is bent by a pressing machine P and solder 9 is deposited on the surface of the outer lead terminal 5. The outer lead terminal 5 is easily bent in the prescribed shape without being caught by the pressing machine by the metal layer composed of tin which allows smooth slide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device in which a semiconductor element is housed in a semiconductor element housing package.

[0002]

2. Description of the Related Art Conventionally, a semiconductor device in which a semiconductor element is hermetically housed in a semiconductor element housing package has been used for an information processing apparatus such as a computer.

A semiconductor device used in such an information processing apparatus is made of an electrically insulating material such as alumina ceramics, and has a recess for accommodating a semiconductor element in a substantially central portion of its upper surface and a peripheral portion of the upper surface to a peripheral portion of the recess. An insulating substrate having a large number of metallized wiring layers made of refractory metal powder such as tungsten, molybdenum, manganese, etc., and silver metal or the like on the metallized wiring layers for electrically connecting a semiconductor element to an external electric circuit. A semiconductor element housing package including an external lead terminal made of Kovar metal or 42 alloy brazed through the brazing material and a lid is prepared. A semiconductor element is mounted and fixed on the bottom surface of the recess through an adhesive such as glass, resin, or brazing material, and each electrode of the semiconductor element is fixed. Electrically connected to the metallized wiring layer via a bonding wire, and thereafter, is fabricated by sealing hermetically the semiconductor element to the container interior made of said insulating base and the lid.

In such a conventional semiconductor device, normally, an external lead terminal is bent into, for example, an L-shape by a pressing method so as to abut the wiring conductor of the external electric circuit board, and solder is pre-welded, By placing the lead terminal on the wiring conductor of the external electric circuit board and abutting it, and re-melting the solder previously welded to the external lead terminal, the external lead terminal and the wiring conductor are solder-bonded to each other to form a semiconductor device. It is designed to be mounted on an external electric circuit board.

[0005]

However, in this conventional semiconductor device, the external lead terminals are made of Kovar metal or 42 alloy, and the Kovar metal or the like has a poor surface slippage. When it is bent into a predetermined shape by a press working method so as to come into contact with the wiring conductor of the circuit board, a part of the external lead terminal is caught by the press working machine and is torn off, and as a result, it is housed inside the semiconductor device. However, there is a drawback that the semiconductor element cannot be accurately and surely electrically connected to the wiring conductor of the external electric circuit board.

[0006]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and an object thereof is to make it possible to easily bend an external lead terminal into a predetermined shape so that the external lead terminal can be used as a wiring conductor of an external electric circuit board. It is an object of the present invention to provide a method for manufacturing a semiconductor device, which enables reliable and strong bonding, and enables accurate and reliable electrical connection of a semiconductor element housed inside to a wiring conductor of an external electric circuit board.

[0007]

According to a method of manufacturing a semiconductor device of the present invention, a semiconductor element is housed inside a container having an external lead terminal attached to an outer surface thereof, and an electrode of the semiconductor element is connected to the external lead terminal. A semiconductor device electrically connected is prepared, a metal layer made of tin is deposited on the surface of the external lead terminal of the semiconductor device, then the external lead terminal is bent by a press working method, and finally the tin It is characterized in that solder is welded to the surface of the external lead terminal to which the metal layer is adhered.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a semiconductor device manufactured by the manufacturing method of the present invention. A semiconductor device A is provided in a container 3 composed of an insulating substrate 1 and a lid 2 of a package for accommodating semiconductor elements. It is manufactured by hermetically housing the semiconductor element 4 and electrically connecting the electrodes of the semiconductor element 4 to the external lead terminals 5 attached to the container 3.

The container 3 of the package for storing the semiconductor element
The insulating base body 1 constituting the above is made of an electrically insulating material such as an aluminum oxide sintered body, a mullite sintered body, an aluminum nitride sintered body, and a silicon carbide sintered body. A concave portion 1a for mounting and fixing the semiconductor element 4 is formed on the bottom surface of the concave portion 1a via an adhesive.

When the insulating substrate 1 is made of, for example, an aluminum oxide sintered body, it is suitable as a raw material powder of alumina (Al ₂ O ₃ ), silica (Si O ₂ ), magnesia (MgO), calcia (CaO), or the like. A ceramic green sheet (ceramic green sheet) is obtained by adding and mixing a variety of organic solvents and solvents to form a slurry and adopting the conventionally known doctor blade method.After that, appropriate punching is performed on the ceramic green sheet. It is manufactured by applying a processing method, stacking multiple sheets, and firing at a high temperature (about 1600 ° C).

The insulating substrate 1 is covered with a plurality of metallized wiring layers 6 from the periphery of the recess 1a to the outer periphery thereof, and the electrodes of the semiconductor element 4 are bonded to the metallized wiring layer 6 around the recesses 1a by bonding wires. It is electrically connected via 7 and external lead terminals are attached to the outer peripheral edge of the insulating base 1.
5 is attached via a brazing material such as silver brazing.

The metallized wiring layer 6 is made of tungsten,
A metal paste made of refractory metal powder such as molybdenum and manganese. A metal paste obtained by adding and mixing an appropriate organic solvent and solvent to refractory metal powder such as tungsten is previously known on the surface of the ceramic green sheet to be the insulating substrate 1. By applying a thick film method such as the screen printing method and printing and coating, the insulating substrate 1 is applied from the periphery of the concave portion 1a to the outer peripheral edge.

The metallized wiring layer 6 may be formed by depositing a metal having excellent corrosion resistance such as nickel and gold and having good conductivity on the exposed outer surface by plating to a thickness of 1.0 to 20.0 μm. Therefore, the oxidative corrosion of the metallized wiring layer 6 can be effectively prevented and the metallized wiring layer 6 can be effectively prevented.
6 and bonding ear 7 and metallized wiring layer 6
The attachment of the external lead terminal 5 to the can be made extremely strong. Therefore, the metalized wiring layer 6 is preferably formed by depositing a metal such as nickel and gold having excellent corrosion resistance and good conductivity on the exposed outer surface to a thickness of 1.0 to 20.0 μm.

The external lead terminals 5 attached to the metallized wiring layer 6 are made of Kovar metal (Fe-Ni-Co alloy) or 42.
It is made of a metal such as an alloy (Fe-Ni alloy), and has one end connected to a wiring conductor of an external electric circuit board to electrically connect the semiconductor element 4 housed inside to an external electric circuit.

The external lead terminal 5 is bent into an L shape so that one end of the external lead terminal 5 comes into contact with the wiring conductor of the external electric circuit board. The external lead terminal 5 is bent by a conventionally known press working method. Is done by doing.

In this case, the external lead terminal 5 is preliminarily coated with a metal layer 8 made of tin on its surface.
The metal layer 8 made of tin makes the bending process extremely easy.

Further, the external lead terminals 5 are further pre-deposited with solder 9 on the surface thereof, which facilitates the workability of joining the external lead terminals 5 to the wiring conductor of the external electric circuit board. I am trying.

The insulating base 1 has a lid 2 bonded to the upper surface thereof via a sealing material, whereby a semiconductor element 4 is hermetically sealed inside a container 3 composed of the insulating base 1 and the lid 2. To be a semiconductor device.

The lid body is made of an electrically insulating material such as an aluminum oxide sintered body or a metal material such as Kovar metal, and is provided on the upper surface of the insulating substrate 1 via a sealing material such as resin, glass, or brazing material. Bonding is performed so as to close the recess 1a provided in the insulating base 1.

Next, a method of manufacturing the above semiconductor device will be described with reference to FIGS. 2 (a) to 2 (d).

First, as shown in FIG. 2 (a), the insulating substrate 1 and the lid are
The semiconductor element 4 is hermetically sealed inside the semiconductor element housing package in which the external lead terminals 5 are horizontally extended outward from the container 3 composed of 2 and the electrodes of the semiconductor element 4 are bonded via the bonding wires 7. A semiconductor device is prepared by electrically connecting to one end of the external lead terminal 5.

The semiconductor element housing package is made of the materials and methods described above, and the semiconductor element 4 is hermetically sealed inside the semiconductor element housing package by the same method as described above.

Next, the semiconductor device is, as shown in FIG.
A metal layer 8 made of tin is deposited on the exposed surface of the external lead terminal 5.

Since the metal layer 8 made of tin is a material in which tin itself is extremely slippery, when the external lead terminal 5 to be described later is bent by a press working method, a part of the external lead terminal 5 is caught by the press working machine. It does not tear and can be bent into a predetermined shape very easily.

Since the metal layer 8 is made of tin, and tin is very well compatible with solder, the solder for joining the external lead terminal 5 to the wiring conductor of the external electric circuit board is previously prepared. External lead terminal when welding
Solder adheres to the surface of 5 with a uniform thickness and firmly.

The metal layer 8 made of tin is deposited on the surface of the external lead terminal 5 by adopting a conventionally known plating method.
Tin 30.0 to 50.0 g / l, sulfuric acid 40.0 to 80.0 g / l, cresol sulfonic acid 30.0 to 60.0 g / l, β-naphthol 0.5 to 1.0 g / l
It is applied to the surface of the external lead terminal 5 by applying a predetermined plating power for a predetermined time while immersing it in a tin plating bath of liter or the like.

Further, the metal layer 8 made of tin has a layer thickness of
If it is set to 3.0 μm or more, bending of the external lead terminals 5 by a press machine becomes extremely easy and soldering to the external lead terminals 5 becomes good. Therefore, the metal layer 8 made of tin to be deposited on the surface of the external lead terminal 5
The layer thickness is preferably 3.0 μm or more.

Next, as shown in FIG. 2 (c), the external lead terminals 5 having the metal layer 8 made of tin deposited on the surface thereof are pressed by a press machine P so that one end side of the external lead terminals 5 is connected to the external electric circuit board. Is bent into a shape such that it easily abuts the wiring conductor, for example, an L-shape.

In this case, since the metal layer 8 made of tin, which is slippery, is adhered to the surface of the external lead terminal 5, when the external lead terminal 5 is bent, a part of the external lead terminal 5 is removed. It does not get caught on the press machine, and as a result, it is possible to easily bend the external lead terminal 5 into a predetermined shape with no breakage.

Next, in the semiconductor device in which one end of the external lead terminal 5 is bent, the solder 9 is welded to the surface of the external lead terminal 5 to form a semiconductor as a final product as shown in FIG. 2 (d). It becomes a device.

The solder 9 is for facilitating the workability of joining when the external lead terminal 5 is joined to the wiring conductor of the external electric circuit board, and the metal layer 8 made of tin is applied thereto. By immersing the external lead terminal 5 in a molten solder bath, it is welded to the surface of the external lead terminal 5. In this case, the surface of the external lead terminal 5 is covered with the metal layer 8 made of tin, which is well compatible with solder, so that the solder 9 is firmly adhered to the surface of the external lead terminal 5 with a uniform thickness.

In the semiconductor device obtained by such a manufacturing method, the external lead terminals 5 are placed on and abutted on the wiring conductor of the external electric circuit board, and the solder 9 previously welded to the external lead terminals 5 is remelted. The external lead terminal 5 and the wiring conductor are soldered and mounted on the external electric circuit board.

[0034]

According to the method of manufacturing a semiconductor device of the present invention, since the metal layer made of tin having good sliding property is deposited on the surface of the external lead terminal, the external lead terminal is bent into a predetermined shape by a press machine. In doing so, a part of the external lead terminal is not caught by the press machine and is torn, and the external lead terminal can be bent into a predetermined shape very easily.

Further, when the external lead terminals 5 are pre-welded with solder, since the metal layer made of tin is deposited on the surfaces of the external lead terminals, the solder is firmly welded and can have a uniform thickness.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a semiconductor device manufactured by a manufacturing method of the present invention.

2 (a) to 2 (d) are cross-sectional views in each step for explaining the manufacturing method of the present invention.

[Explanation of symbols]

 1 ... Insulating substrate 2 ... Lid 3 ... Container 4 ... Semiconductor element 5 ... External lead terminal 6 ... Metallized wiring layer 8・ ・ ・ ・ ・ Metal layer made of tin 9 ・ ・ ・ Solder A ・ ・ ・ Semiconductor device P ・ ・ ・ ・ ・ Press machine

Claims (1)

[Claims] 1. A semiconductor device in which a semiconductor element is housed inside a container having external lead terminals attached to its outer surface and electrodes of the semiconductor element are electrically connected to the external lead terminals is prepared. A metal layer made of tin is applied to the surface of the external lead terminal of the device, then the external lead terminal is bent by a press working method, and finally the surface of the external lead terminal to which the metal layer of tin is applied is applied. A method for manufacturing a semiconductor device, which comprises soldering.