JP2849878B2 - Manufacturing method of electronic component mounting board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an electronic component mounting board in which each lead is formed by an inner lead member and an outer lead member formed separately.

[0002]

2. Description of the Related Art Various types of electronic component mounting substrates for electrically connecting electronic components such as semiconductor chips to the outside have been proposed. Among them, there is a type in which a large number of leads for electrically connecting the electronic component to the outside are projected from an insulating base material for mounting the electronic component. In some cases, the lead 20 as shown in (1) is composed of an inner lead member 20a and an outer lead member 20b formed separately.

[0003] Such an electronic component mounting board is formed by mounting the electronic component on an insulating base material and sealing the whole with a so-called mold resin in a state where the outer lead member is protruded. It will be a mounting device.

Incidentally, since the electronic component mounting board as described above is composed of an inner lead member and an outer lead member in which each lead is formed separately,
In the manufacturing process, it is necessary to electrically and physically integrate both lead members.

Therefore, conventionally, in the manufacturing process of this type of electronic component mounting board, in order to form the leads, a predetermined outer end of the inner lead member and a predetermined inner end of the outer lead member are formed. A manufacturing process is included in which both ends are electrically and physically integrated by joining the ends with a brazing material such as solder which is a conductor electrically.

[0006]

However, when the leads 20 are integrated by the above-described manufacturing process, there will be no need for the joints between the inner lead member 20a and the outer lead member 20b as shown in FIG. The material 40 may flow out, and the thickness of the lead 20 may become uneven due to the brazing material 40 flowing out. Then, as shown in FIG. 5, when these are sealed with the mold resin, the uneven thickness of the leads 20 interferes with the mold dies, and a gap is formed between the upper and lower mold dies. When the mold resin is injected into the mold, the resin may flow out of the gap.

Therefore, when the lead 20 is formed by joining the separately formed inner lead member 20a and outer lead member 20b, according to the above-described conventional manufacturing process, the upper and lower mold dies are used. In order to prevent a gap from being generated between the leads 20 by cutting or the like after joining.
However, there are drawbacks in that a complicated operation such as making the thickness of the substrate uniform is required, and it is difficult to easily obtain a high-quality electronic component mounting substrate.

The present invention was devised in view of the above circumstances, and an object of the present invention is to limit the outflow range of the brazing material flowing out from each joint between the inner lead member and the outer lead member, thereby achieving a high level. It is an object of the present invention to provide a manufacturing method capable of easily obtaining a quality electronic component mounting substrate.

[0009]

In order to solve the above problems, the means adopted by the present invention will be described with reference to the reference numerals used in the following embodiments. Lead member 20a and outer lead member 20
b are integrally joined with a brazing material 40 such as solder to form a large number of leads 20, and the insulating base 10 is integrated with both sides of these leads 20 so that each lead 20 protrudes outward. What is claimed is: 1. A method for manufacturing an electronic component mounting board 100, comprising: forming the electronic component mounting board 100; (A) forming a flow prevention dam 30 for preventing the flow of the brazing material 40 at each predetermined position of the outer lead member 20b; (b) predetermined outer ends of the inner lead member 20a and the outer lead member 20b Step of joining each predetermined inner end with the brazing material 40 to form each lead 20 "
It is.

That is, the feature of the manufacturing method according to the present invention is that the inner lead member 20a and the outer lead member 2
Before the step of joining the soldering material 0b with the brazing material 40, a step of forming the outflow prevention dam 30 for limiting the outflow range of the brazing material 40 on the outer lead member 20b is included.

The outflow prevention dam 30 is formed by forming the outflow prevention dam 30 formed into a frame shape by punching or the like on the outer lead member 20b with an adhesive, or by a printing method or a stamping method. Any method may be used. The material is not particularly limited as long as it can withstand heating when the brazing material 40 is melted. After joining the inner lead member 20a and the outer lead member 20b, the unnecessary outflow prevention dam 30 is removed. From the viewpoint of easy removal, peelable polyimide and polycarbonate soluble in an organic solvent are preferable. Further, the shape of the outflow prevention dam 30 is not particularly limited, such as a frame shape as shown in the embodiment or a shape formed only on the upper surface of the outer lead member 20b. Any shape that has a dam action to prevent the outflow of
It may be a material.

[0012]

By adopting the above means, the manufacturing method according to the present invention operates as follows. That is,
By forming the outflow prevention dams 30 at predetermined positions of the outer lead member 20b in advance, at the time of joining the inner lead member 20a and the outer lead member 20b, the outflow of the brazing material 40 occurs at the end face of the outflow prevention dam 30. Since it is prevented, no trouble occurs in the subsequent manufacturing process.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a method for manufacturing an electronic component mounting board according to the present invention will be described with reference to one embodiment shown in the drawings.

FIGS. 1 and 2 show an electronic component mounting substrate 100 formed by employing the manufacturing method according to the present invention. First, the structure of the electronic component mounting board 100 will be described.
The outer lead member 2 protrudes outward from the inner lead member 20 and is formed separately from the inner lead member 20a.
Reference numerals 0b are connected by a dam bar 21, and an outflow prevention dam 30 is attached to a predetermined position in a frame shape. The predetermined outer ends of the inner lead member 20a and the predetermined inner ends of the outer lead member 20b are connected to a brazing material 4 such as solder.
0.

Next, a method of manufacturing the electronic component mounting board 100 will be described. First, by the conventional manufacturing method, on both surfaces of the inner lead member 20a made of copper material,
A prepreg is thermocompression-bonded so that the inner lead member 20a protrudes outward to form an insulating base material 10, and a conductive circuit (not shown) is formed on the insulating base material 10 by etching or the like.
To form

Next, the outflow prevention dam 30 is formed on the outer lead member 20b formed of a copper material and connected by the dam bar 21. Here, the outflow prevention dam 30 is formed as a square frame having a height of 0.2 mm by a tape material made of polyimide so that the outflow prevention dam 30 is housed in a mold when it is later sealed with a mold resin. You.

Next, predetermined outer ends of the inner lead member 20a are positioned at predetermined inner ends of the outer lead member 20b, and a brazing material 40, such as solder, which is an electrically conductive material.
The outer lead member 20b and the inner lead member 20
to form a lead 20 that is electrically and physically integrated. At this time, the outflow of the brazing material 40 from the joint is prevented by the outflow prevention dam 30.

Finally, the unnecessary outflow prevention dam 30 is peeled and removed, and the dam bar 21 is cut by punching to obtain the electronic component mounting substrate 100. In this case, as shown in FIG. 3, the outflow prevention dam 30 is provided at a position to be accommodated in the molding resin to be sealed. Therefore, it is not always necessary to remove the outflow prevention dam 30.

As shown in FIG. 3, the electronic component mounting substrate 100 thus formed is sealed with a mold resin after mounting the electronic components, thereby forming an electronic component mounting apparatus.

[0020]

As described above in detail, according to the manufacturing method of the present invention, the outflow prevention dam is formed at each predetermined position of the outer lead member, so that the inner lead member and the outer lead member are formed. At the time of joining, the outflow of brazing material is prevented at the end face of the outflow prevention dam, and no trouble occurs in the subsequent manufacturing process, so that a high-quality electronic component mounting substrate can be easily manufactured. .

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of an electronic component mounting board manufactured by a manufacturing method according to the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

3 is a cross-sectional view of an electronic component mounting apparatus configured using the electronic component mounting board shown in FIG.

FIG. 4 is a cross-sectional view of the electronic component mounting board showing a state in which the brazing material has flowed out.

FIG. 5 is a cross-sectional view of a state in which the electronic component mounting substrate in which the brazing material has flowed out is housed in a mold.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Insulating base material 20 Lead 20a Inner lead member 20b Outer lead member 21 Dam bar 30 Outflow prevention dam 40 Brazing material (solder) 100 Substrate for mounting electronic components

Claims (1)

(57) [Claims] 1. An inner lead member and an outer lead member formed separately are integrally joined with a brazing material such as solder to form a large number of leads, and each lead is provided on both sides of these leads. A method for manufacturing an electronic component mounting board, wherein an insulating base material is integrally formed so as to protrude toward the electronic component mounting method, comprising the following steps: . (A) forming outflow prevention dams at each predetermined position of the outer lead member to prevent the outflow of the brazing material; (b) predetermined outer ends of the inner lead member and predetermined inner portions of the outer lead member. Joining each end with the brazing material to form each lead.