JPH0456461B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a method of manufacturing a hybrid integrated circuit.

[Technical background of the invention and its problems]

Conventionally, hybrid integrated circuits have been manufactured as shown in FIGS. 1 and 2. That is, after printing solder paste at required locations on an insulating substrate, such as a circuit wiring board formed by thick film paste printing on one side of a ceramic substrate 1, integrated circuit elements (ICs), transistors, and diodes are printed on the solder paste. Mount components such as semiconductor elements 2 and capacitors 3, heat them with a hot plate, etc., and solder them 4.
Along with cleaning, function trimming,
The method for taking out the outer leads of a hybrid integrated circuit, which is attached to a case (not shown) after undergoing processes such as characteristic checking, is as follows. First, as shown in FIG. 1A, the outer lead 5 having the head 6 is attached to the substrate 1.
It is installed perpendicularly to the outer lead extraction electrode section of the terminal, and is soldered at that electrode section. However, with this method, the leads 5 must be soldered one by one, which takes time and is not suitable for mass production. Furthermore, since the connection between the board 1 and the leads 5 is made only by soldering, the adhesive is not able to withstand tension. It has the disadvantage of being weak in strength.

There is a method shown in FIG. 1B that improves this adhesive strength. In this case, a hole 7 is provided in the part of the substrate 1 where the outer lead 5 is installed, and the lead 5 having the head 6 is inserted from the back side of the substrate 1.
However, in this method, the leads 5 are inserted one by one from the back side, which has the disadvantage of poor workability, and because the contact area of the soldered portion 4 on the surface of the board 1 is small, it tends to become open. Therefore, the first method was developed to increase this contact area.
There is a method shown in Figure C. This is Outer Lead 5
This lead 5 has a collar 8 in the middle.
is inserted from the front surface of the substrate 1, and is firmly fixed by crushing the portion of the lead 5 protruding from the back surface. However, this method also has the drawback that the leads 5 must be inserted one by one, and furthermore, an additional work step for crushing the protruding portions of the leads 5 on the back side of the substrate 1 is added.

Therefore, we have developed a second method that eliminates the complexity of soldering the leads 5 one by one to the electrode parts as described above, improves the adhesive strength against tension, and improves the floating from the substrate 1. There is a method as shown in the figure. That is, in FIGS. 2A and 2B, solder paste is printed on the board 1 in advance, and the leads 5 are soldered to the solder paste part at the same time as the electronic parts, and a lead frame in which multiple leads are integrated is used. It is something. In addition, in FIG. 2C, a hole 7 is provided in advance in the board 1 as in FIGS. It is something to do. Furthermore, Figure 2 D and E are
A lead 5 having a concave tip is installed so that the recess 10 of the lead 5 bites into the electrode part of the substrate 1, and in this state it is fixed by soldering.

However, these lead frames have a stronger and easier attachment force to the substrate 1 than the lead pins shown in Fig. 1, but since each lead is integrated, it is necessary to attach the leads before checking the function trimming characteristics. Must be disconnected. In addition, in both the lead pins and lead frames in both Figures 1 and 2, the leads 5 protrude from the board 1, so the heat soldering, cleaning, and fusing after attaching the leads to the solder paste printed board are difficult. When checking the trimming characteristics, there was a problem that it was difficult to handle and the workability was extremely poor.

[Purpose of the invention]

This invention was made in view of the above points,
The purpose is to add Sn to the electrode part from which the leads of the board are taken out.
A metal piece made of an Fe plate or Fe alloy plate plated with a low melting point metal such as Pb or Zn or its alloy is soldered, and this metal piece is made of Cu or a Cu alloy plated with the same plating process as the metal piece. To provide a method for manufacturing a hybrid integrated circuit which improves workability by welding the leads, enables reliable and strong attachment of the leads, improves reliability, and is excellent in mass production. It is in.

[Summary of the invention]

The electrode part from which the leads of the board are taken out is plated with low melting point metals such as Sn, Pb, and Zn, or their alloys.
By soldering a metal piece made of an Fe plate piece or an Fe alloy plate piece and welding a lead made of Cu or Cu alloy that has been plated in the same way as the metal piece, the lead can be made reliable and strong. Installation is in progress.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. First, as shown in FIG. 3A, a circuit wiring board is formed by thick film paste printing on one side of a ceramic substrate 31 serving as an insulating substrate, and solder paste is printed on the electronic component mounting portion of this circuit wiring board. Next, active elements and passive elements, that is, semiconductor elements 32 such as ICs and transistors, capacitors 33, etc. are soldered to the parts provided with this solder paste, and at the same time, metal pieces 35 etc. are soldered to the electrode parts 34. do. The metal piece 35 may be a low melting point metal such as tin (Sn), lead (Pb), or zinc (Zn) or an iron (Fe) plate plated with an alloy thereof, but in the embodiment, uses Sn-plated steel. Next, after this soldering process is completed, processes such as cleaning and checking the function trimming characteristics are performed.

Next, as shown in FIG. 3B or C, a lead 37 or a lead frame 38 having a head 36 is automatically welded to the metal piece 35 using, for example, a welding machine. The leads 37 and lead frame 38 may be made of copper (Cu) or a copper alloy that has been plated in the same manner as the metal pieces, but in the embodiment, solder plated copper is used.

Further, as described in the above embodiment, the metal piece 3
5 is an iron piece that has been plated with Sn, and further in a general sulfuric acid bath at a current density of 0.5 to 1 A/ ^cm2 at a current density of 1.0 to 1.5.
Lead 37 by applying time barrel plating
After solder plating with a plating thickness of 3 to 8 μm and automatically welding the metal piece 35 and the lead 37, a strength test (tensile test) was conducted, which showed sufficient strength of 8 kg or more. Therefore, the lead 37 is not cut due to tension and is not separated from the welding surface, so that the reliability of welding the lead 37 to the substrate 31 can be improved.

〔Effect of the invention〕

As described in detail above, according to the present invention, when attaching leads to the electrode parts of a hybrid integrated circuit board, an Fe plate piece or an Fe plate plated with a low melting point metal such as Sn, Pb, or Zn or an alloy thereof or an alloy thereof is used.
A metal piece made of an alloy plate piece is soldered, and this metal piece is coated with Cu or plated in the same way as the metal piece.
Since the lead made of Cu alloy is welded, reliable welding between the lead and the metal piece can be obtained.

[Brief explanation of the drawing]

1 and 2 are diagrams for explaining a conventional method for manufacturing a hybrid integrated circuit, and FIG. 3 is a diagram for explaining an embodiment of the method for manufacturing a hybrid integrated circuit according to the present invention. 31... Ceramic substrate, 34... Electrode part, 3
5...metal piece, 36...head, 37...lead, 38...lead frame.

Claims (1)

[Claims] 1. When attaching leads to the electrodes of a hybrid integrated circuit board, first solder a metal piece made of an Fe plate or Fe alloy plate plated with a low melting point metal such as Sn, Pb, or Zn or its alloy,
A method for manufacturing a hybrid integrated circuit, which comprises welding to this metal piece a lead made of Cu or Cu alloy, which has been plated in the same manner as the metal piece and has a plating thickness of 3 to 8 μm.