JPH0629654A - Electronic device - Google Patents

Abstract

(57) [Abstract] [Purpose] To realize the simplification of solder application work on 3D circuits. [Structure] Reference numeral 19 denotes a pattern formed in a mounting portion of the electronic component 17 (a portion where leads such as a chip component and an IC are located). A mold is formed such that the portion where the pattern 19 is formed becomes a recess, and a molded product 11 is produced by injection molding using this mold. In the subsequent pattern forming step, after applying the solder resist, the solder 16 is deposited in the recess by plating. When the solder 16 is passed through the reflow furnace, the solder 16 is melted and the electronic component 17 is connected only in the recess. [Effect] Even with a three-dimensional shape, solder can be applied all at once, so workability is improved, and positioning of the electronic component 17 is possible because the dangling connection portion is a recess. Therefore, it is possible to prevent the displacement of the electronic components or the defects such as the solder bridge.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device having a three-dimensional electric circuit on its front and back surfaces.

[0002]

2. Description of the Related Art In recent years, three-dimensional (three-dimensional) molded products have been produced by injection molding from those which have been used in a planar shape as represented by conventional glass epoxy substrates, and the conventional substrate Electronic devices in which other functions (for example, chassis and housing) are integrated have been used in automobile parts and the like.

FIG. 4, FIG. 5 and FIG. 6 are block diagrams of conventional electronic devices. 1 is a synthetic resin injection molded product, 2
Is a copper foil portion formed by electroless plating, 3 is a photosensitive film for forming a circuit pattern (hereinafter referred to as resist), 4 is a copper foil portion formed by electrolytic plating (hereinafter,
5) Protects a pattern other than the pattern 9 of the component mounting portion, and a protective material (hereinafter referred to as a solder resist) for preventing a solder bridge between leads of the IC package, and 7 is an electronic component such as an IC package. , 7a are leads of the electronic component 7, 8 is cream solder, and 9 is a pattern of the component mounting portion.

A conventional electronic device will be described below.
At present, injection-molded parts are formed by the process shown in FIG. First, a molded product 1 is made by injection molding using a resin having high heat resistance, and after molding, a treatment is performed to make it easy for plating to be deposited on the surface of the molded product 1.

Next, electroless copper plating 2 is applied to the entire molded product to connect through holes and the like, and resist 3 is applied thereon.

After that, the resist of the portion which becomes the pattern is removed by light, and the removed portion is subjected to electrolytic copper plating 4 to form a final pattern portion. Then, the resist is peeled off, and the electroless copper-plated portion is removed by etching. Finally, apply solder resist 5,
It will be a finished product.

To mount the electronic component 7 on the electronic device manufactured by the above process, the electronic component 7 is temporarily fixed with an adhesive and then connected through a solder bath, or using a dispenser or the like. Cream solder is applied to the pattern 9 of the component mounting portion, the electronic component 7 is mounted, and the components are connected by reflow. At present, temporary fixing of the electronic component 7 with an adhesive, application of cream solder with a dispenser, and mounting of the electronic component 7 are performed manually.

[0008]

However, in the conventional structure as described above, in a three-dimensional three-dimensional circuit, a cream is collectively printed by screen printing using a metal mask as is done on a printed circuit board. Solder application is difficult. For this reason, cream solder is applied using a dispenser or the like, or when soldering electronic components that pass through a solder bath, solder chips such as a very small chip or an IC package with a small lead pitch may cause soldering defects such as solder bridges. It causes problems such as being easy to get up. Also, since most of the manual work is performed, workability is poor.

[0009]

According to the present invention, a recess is provided in a component mounting portion (solder connection portion) of an electronic device having a three-dimensional electric circuit on the front and back surfaces, and solder is formed by plating in the recess. is there.

[0010]

According to the present invention, with the above-mentioned structure, solder can be applied all at once even for a molded product having a three-dimensional shape.

[0011]

An embodiment of the present invention will be described below with reference to the drawings.

1, 2, and 3 are block diagrams of an electronic device according to an embodiment of the present invention. In the figure, 11 is a molded product formed by injection molding of synthetic resin, 12 is a copper foil portion formed by electroless plating, 13 is a photosensitive film for forming a circuit pattern, and 14 is a copper foil portion formed by electrolytic plating. Is. Reference numeral 15 is a protective material for protecting patterns other than the pattern of the component mounting portion and for preventing solder bridge between leads of the IC package. 16 is a solder for connecting electronic parts formed by plating, 17 is an electronic part, 1
Reference numeral 7 a is a lead of the electronic component 17. Reference numeral 18 is a cream solder, and 19 is a pattern of a component mounting portion. Reference numeral 20 is a recess formed in the electronic component connecting portion of the molded product 11.

A method of manufacturing the electronic device having the above-described structure will be described below.

FIG. 1 shows a manufacturing process diagram of the electronic device of the present invention. First, as shown in FIG. 1, pattern 1 of electronic component 17
A mold is manufactured so that the portion where the 9 is formed becomes the recess 20, and a molded product 11 is produced by injection molding. The subsequent pattern formation process is the same as in the conventional example (FIG. 1).
And FIG. 4). In FIG. 1, after applying the solder resist, the solder 16 is deposited in the recess by plating.

Through the above steps, the electronic device of the present invention is formed. Regarding mounting of the electronic component 17, FIG.
(A) and FIG. 3 (a) are mounted, but the electronic component 17 to be mounted on the flat surface portion can be positioned because the solder connection portion is a recess. . When mounting the electronic component 17 on the inclined portion, it is temporarily fixed with an adhesive or the like in order to prevent the electronic component 17 from dropping or shifting. After mounting the electronic component 17 as described above, the solder 1
6 melts, and the electronic component 17 is connected only in the recess 20 (see FIGS. 2B and 3B).

[0016]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, in an electronic device having a three-dimensional electric circuit on the front and back surfaces, a concave portion is provided in a mounting portion of an electronic component to be mounted (a portion where a lead such as a chip component or an IC is located). It is provided and solder is formed in this recess by plating.With such a configuration, it is possible to apply the solder all at once, and the manual soldering process is not required, and workability is improved. Get better. In addition, since the solder connection portion is a concave portion and the solder is joined in the concave portion, a defect such as a shift of electronic components when the solder is melted by reflow or a solder bridge between leads of an IC package having a small lead pitch occurs. It can be prevented.

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram of an electronic device according to an embodiment of the present invention.

FIG. 2A is a cross-sectional view showing a state before mounting the electronic component and performing reflow in the manufacturing process of the same electronic device. FIG. 2B is a sectional view showing the state after mounting the electronic component and performing reflow in the manufacturing process of the same electronic device. Sectional view showing the state of

FIG. 3A is a perspective view showing a state before mounting the electronic component and performing reflow in the manufacturing process of the electronic device, and FIG. 3B is a perspective view illustrating the state after mounting the electronic component and performing reflow in the manufacturing process of the electronic device. Perspective view showing the state of

FIG. 4 is a manufacturing process diagram of a conventional electronic device.

FIG. 5A shows a conventional electronic device manufacturing process,
Sectional drawing which shows the state before mounting reflow and mounting electronic parts. (B) is a sectional view which shows the state after reflowing after mounting electronic parts in the manufacturing process of the same electronic device.

FIG. 6 (a) shows a conventional electronic device manufacturing process,
FIG. 3B is a perspective view showing a state before mounting the electronic component and performing reflow, and FIG. 3B is a perspective view showing a state after mounting the electronic component and performing reflow in the manufacturing process of the electronic device.

[Explanation of symbols]

 11 Molded Product 12, 14 Copper Foil 13 Photosensitive Film 15 Protective Material 16 Solder 17 Electronic Component 18 Cream Solder 19 Pattern 20 Recess

Claims (1)

[Claims] 1. An electronic device having a three-dimensional electric circuit on the front and back surfaces, wherein a recess is provided in a portion where a lead of an electronic component to be mounted is located, and a solder is formed in the recess by plating.