JPS6239093A - Part package of printed circuit board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for mounting chip components and discrete components on both sides of a printed circuit board.

(Prior Art) Conventionally, when chip components and discrete components are mixedly mounted on both sides of a printed circuit board, a method as shown in FIG. 3 has been adopted. That is, in FIG. 3, 1 is a double-sided printed circuit board, 2 is a conductor pattern formed on both sides, 3 is a through hole for connecting circuits on both sides,
4 is a solder resist film covering both surfaces except for the conductor portions.

Using such a board J, first, as shown in FIG. 3(a), solder paste 5 is applied to a predetermined part of the conductor pattern 2 on the main surface A of the board 1 by screen printing etc. Place the chip components so that the terminals are located at the edges, and solder them using reflow soldering. FIG. 3(b) shows a state in which chip components 6 are joined with solder 7 by solder paste flow soldering.

Next, on the main surface B of the substrate 1, as shown in FIG. Agent 9
Further, the lead wire of the discrete component 10 is passed through the through hole 3 from the main surface A side.

In this state, the main surface B is immersed in molten solder, and the chip component 8 and the discrete component 10 are soldered.

(Problem to be solved by the invention) However, in the above mounting method, the main surfaces A and B
Since the soldering methods are completely different, separate equipment must be prepared for each method, which is economically disadvantageous. Furthermore, printing method is generally applied to apply the solder paste on the main surface A, but in this case, due to warpage of the board and unevenness of the surface, as printing is repeated, the solder paste gradually spreads to the back side of the plate. It spins and sticks, causing smearing at the edges of the printed pattern. As a result, there were problems such as short-circuiting between the conductor patterns due to solder, which caused defects.

The present invention solves the above problems and provides a method for mounting components on a printed circuit board that simplifies the process, reduces costs, and eliminates defects caused by printing.

(Means for solving the problem) First, on the main surface A of the printed circuit board, after masking the through holes, the chip components are placed in predetermined positions and fixed to the board with adhesive, and then the main surface A dipped in solder to solder chip parts. Next, on the main surface B, the chip components are placed in a predetermined position and fixed to the substrate with adhesive, and the masking is pierced or removed from the main surface A side, and the lead wires of the discrete components are passed through the through holes.
The main surface B side of the board is dipped in solder to solder chip components and discrete components.

(Function) According to the method of the present invention, parts are soldered on both sides of the board by solder dipping, so only one type of equipment is required, and since the printing method of solder paste is not applied, the occurrence of defects due to this is avoided. do not have.

(Example) Embodiments will be described in detail below based on the drawings.

FIG. 1 shows one embodiment of the present invention, where 1 is the third
It is a double-sided board with the same configuration as the board shown in the figure. 2 is a conductor pattern, 3 is a through hole, and 4 is a solder resist film.

First, on the main surface A of the substrate 1, the through holes 3 are masked 11 as shown in FIG. 1(a). This masking 11 is made of heat-resistant resin. Then,
As shown in FIG. 1(b), the chip components 6 are arranged so that the terminal portions are located at predetermined positions of the conductor pattern 2, and are fixed to the substrate with an adhesive 9. Thereafter, the main surface A is immersed in molten solder, and the chip component 6 is bonded with the solder 7.

Next, on the main surface B of the board, as shown in FIG. It is fixed to the substrate 1. Furthermore, the masking 11 is broken through from the main surface A side, and the lead wire of the discrete component 10 is passed through the through hole 3. In this state, main surface B is immersed in molten solder,
The chip component 8 and the discrete component 10 are soldered.

As described above, in this embodiment, soldering on the main surfaces A and B of the board is performed by immersion in molten solder, so only the equipment for this is required, and conventional glue flow soldering can be used in combination. The soldering process is much simpler than that.

Furthermore, since printing of solder paste is not applied, defects due to printing bleeding do not occur.

Note that the through-hole masking 11 in the embodiment shown in FIG. 1 is formed to cover the entire portion of the through-hole 3 exposed on the main surface A side, and the masking must be removed when inserting the lead wire of the discrete component 10. However, as shown in Figure 2, the masking 1 filled in a part of the through hole 3
It may be set to 2. In this case, the masking 12 is removed when inserting the discrete component.

(Effects of the Invention) As explained above, according to the present invention, when mounting components on both sides of a board, a soldering method is adopted for both sides by immersion in solder, so only the equipment for this is prepared. The soldering process is greatly simplified compared to conventional methods. Furthermore, since printing of solder paste is not applied, there is no occurrence of defects such as short circuits between conductive patterns due to printing smear, and therefore cost reduction and quality improvement can be achieved.

[Brief explanation of the drawing]

FIG. 1 shows Il! of one embodiment of the present invention. FIG. 2 is a cross-sectional view showing another embodiment of through-hole masking, and FIG. 3 is a cross-sectional view showing a conventional method. 1...Double-sided board, 2...Conductor pattern, 3.
...Through hole, 4 ...Solder resist film, 6.8
...chip parts, 7 ...solder, 9 ...
Adhesive, 10... Discrete parts, 11, 12
···masking. Patent applicant: Tohoku Ricoh Co., Ltd. Agent Tsuneji Hoshino - 2' and ' - Buddha Figure 1 (a) Figure 2 Figure 3 (a) (b)

Claims (1)

[Claims] On one main surface of a printed circuit board that has through holes for electrically connecting both sides of the board, the through holes are masked, and terminal portions are respectively placed at predetermined portions of the conductor layer formed on the one main surface. After arranging the chip components so that the printed circuit board is located and fixing them to the board with adhesive, one main surface of the chip components is immersed in molten solder to solder the chip components, and then the other main surface of the printed circuit board is immersed in molten solder to solder the chip components. The chip components are arranged so that the terminal portions are respectively located at predetermined locations on the conductor layer formed on the substrate, and are fixed to the substrate with an adhesive, and the masking is broken through or removed to separate the discrete components from the one main surface. A method for mounting components on a printed circuit board, characterized in that after inserting a lead wire of a component into the through hole, the other main surface is immersed in molten solder to simultaneously solder the chip component and the discrete component.