JPS60182189A - Soldering method - 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 [Technical Field] The present invention relates to a soldering method for electrically connecting a printed circuit board, such as a flexible printed circuit board, and a member to be soldered, such as an electronic component, to a printed circuit board.

[Prior art]

Conventionally, such a method for soldering a printed circuit board and a member to be soldered is performed as shown in FIGS. 1 to 3, for example.

That is, in FIGS. 1 and 2, the printed circuit board 1
To connect the wiring pattern 2 and the wiring or turn 4 of the printed circuit board 3 such as a flexible printed circuit board with solder, pre-solder is applied to at least one of the wiring patterns 2 and 4. In the illustrated example, four For soldering, there is a contact heating method in which a soldering iron 6 (FIG. 2) with a temperature control function that covers the entire part is pressed against the board 3 to melt the solder 5 and perform soldering. In this case, if the iron 6 and the board 1 are not parallel, one solder will melt but the other will not, resulting in uneven melting of the solder.
Soldering causes defects. Furthermore, if the amount of pre-solder differs depending on the location, if the amount of pre-solder is less than the appropriate amount in a certain location, unsoldering will occur, and if it is large, solder bridges will occur between adjacent solder locations. Therefore, in order to prevent defects in these soldering methods, it is currently impossible to make the wiring/guts narrow. In addition, when the number of welding is increased to melt the unmolten solder, the flux sticks to the solder iron 6, which increases the thermal resistance between the solder iron 6 and the printed circuit board 4, resulting in poor workability and shortening the life of the solder iron 6. I will do it.

On the other hand, when connecting the wiring line 2 of the printed circuit board 1 and the electrode part 4' of the electronic component 3' with the solder 5 as shown in FIG. Reflow soldering is used, or electronic components are temporarily fixed with adhesive and flow soldered.

In these methods, if the spacing between the wiring pattern 2 on the board 1 and the adjacent wiring/turn 2 is narrow, solder bridging will easily occur, so it is necessary to make the spacing between the lower turns a certain degree wide. The drawback was that high-density packaging was not possible.

[Purpose of the invention]

One object of the present invention is to provide a soldering method that can effectively prevent solder defects such as uneven melting of solder, unsoldered material, solder blots, and cracks.

Another object of the present invention is to provide a soldering method that enables high-density mounting of boards because soldering does not cause defects even when the distance between soldering parts is narrowed. .

Another object of the present invention is to improve soldering workability.
The object of the present invention is to provide a method for soldering that is efficient, maintains the soldering jig, etc.

The above object is to provide a method of soldering a printed circuit board and a soldered member at a single or multiple predetermined locations, at least the soldering is performed using solder that holds solder in the position necessary to connect the locations. This is achieved by sandwiching the holding member between the printed circuit board and the member to be soldered and performing soldering.

[Preferred embodiments of the invention]

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings 4 to 6.

FIG. 4 is a diagram for explaining one embodiment of the present invention.
11 is a printed circuit board, and 12 is a wiring pattern of the board 11. The wiring patterns 12 are connected to the substrate 1 at equal intervals A.
It is located on 1. Further, 13 is a printed circuit board such as a flexible printed circuit board which is soldered to the board 11, and 14 is one turn of the wiring of the board 13. The wiring pattern 14 has an interval A'f equal to the interval of the pattern 12.
: Disposed on the board 13 with a gap. In the example of FIG. 4, these four soldering parts (with turns 12 and 14 facing each other) form a soldering part.The number of soldering parts of the present invention is not limited to this, but one or two Any number greater than or equal to one is acceptable.

Reference numeral 15 in FIG. 4 denotes a solder holding member, which is composed of an electrically insulating plate having a plurality of holes 17 passing through in the thickness direction for holding solder 16. As shown in FIG. 6, the through holes 17 are arranged at equal intervals B in the vertical and horizontal directions of the insulating plate, and have the same hole diameter C.

When soldering multiple parts as in the example of Figs. 4 and 5, the pitch of the pattern 12°14, that is, the length of the pattern interval A plus the width of the pattern, Although it is essential to make the interval B between the through holes 170 narrower, it is also necessary to make the diameter C of the through holes 17 narrower with respect to the interval A.
By making the solder holding member smaller, unnecessary positioning of the solder holding member can be omitted, which is preferable. Under such conditions, each of the opposing patterns 12 and 14 can be connected with at least one of the solders 16 held in the through hole 17.
For soldering, the location and arrangement of the through holes can be selected as appropriate.

The holding member 15 holding the solder in this way is attached to the substrate 11.1.
When soldering between 3 and 3, the diameter C of the through hole 17
However, if the diameter is small enough that the molten solder does not fall off due to capillary action, or even if it falls off, the board 11
．． 13, the soldering iron 6 can be brought into contact with the substrate 13 by the method shown in FIG. 2, for example, so as to heat the entire solder holding member.

In addition, on the contrary, the diameter C of the through hole 17 is large enough to allow the molten solder to fall off, causing the board 11.
If this is the case, it is preferable to irradiate each solder portion with a laser beam from above the substrate 13 and perform spot heating to solder the solder portions to prevent the solder from falling off at other portions. Further, in order to prevent short-circuit failures due to falling of molten solder, it is preferable to cover the parts other than the soldering parts of at least one of the boards 11 and 13 with a solder resist.

According to the example shown in FIGS. 4 and 5, even if the pitch of the wiring pattern is about 0.06 WM,
It is possible to make the hole diameter of the through hole 0.06 mm or less, and high-density mounting that can be used even with a narrow pitch, for example, 16 pet mounting is possible.

The material of the solder holding member is not particularly limited, but an electrical insulator, particularly a non-conductive resin or elastomer, is suitable. Of these, thermal deformation, melting, and
Resins or distomers that do not decompose, especially fluororesins, fluororubbers, silicone resins, silicone rubbers, polycarbonate resins, epoxy resins, polyimide resins, polyimidazole resins, polyimide amide resins, polydiphenyl ether resins, etc. can be used. .

FIG. 5 is a diagram for explaining another embodiment of the present invention. In this example, the wiring pattern 22 of the printed circuit board 21. For example, when soldering an electrode portion 24 of an electronic component 23 such as a chip resistor, a multilayer ceramic capacitor, a flat five-no-cage type IC, a chip component, or a lead component, as shown in FIG. Using the solder holding member 15 shown and explained in FIGS. 4 and 6, the solder 16 in the through hole 17 is melted by spot heating, heating with a soldering iron, etc. without performing flow soldering. Then, perform soldering.

In addition, in the examples shown in FIGS. 4 and 5, the solder holding member 15 itself can be used as a wiring pattern and used as a jumper wire.

In addition, if the inner wall of the through hole 17 of this member 15 is subjected to a treatment such as plating, even if the solder is absorbed into the wiring arm turn 2, the pattern of the soldered member 3, and the electrode portion 12 of the electronic component 7, Since electrical continuity can be achieved, high-quality soldering is possible.

〔Effect of the invention〕

According to the present invention, it is possible to prevent soldering defects such as unsolder and solder spots, and also to prevent soldering defects from occurring even when the soldering parts are close to each other, so that the board is densely packed. implementation can be made possible. It also effectively prevents flux from sticking to jigs such as soldering irons, improving soldering workability and efficiency.
Soldering can be said to be an excellent method in terms of maintaining soldering properties.

[Brief explanation of drawings]

Figures 1 to 3 are diagrams for explaining the conventional soldering method. A schematic diagram showing the soldered state, Figure 2 is the 1st
FIG. 3 is a cross-sectional view showing a state in which the soldering shown in the figure is performed with a soldering iron, and FIG. 3 is a cross-sectional view showing a state in which a printed circuit board and an electronic component are soldered. Figures 4 to 6 are diagrams for explaining the soldering method of the present invention, and Figure 4 shows a printed circuit board and a board to be soldered, such as a flexible printed circuit board, in which a plurality of soldering parts are connected. 5 is a sectional view showing a printed circuit board and an electronic component soldered together, and FIG. 6 shows the shape of a solder holding part used in the present invention. FIG. 1.11.21... Printed circuit board, 2.2', 12゜22... Wiring pattern, 3.13... Flexible printed circuit board, 3', 23... Electronic component, 4.14.
...Wiring pattern, 4', 24...Electrode part, 5.16
...Solder, 6...Solder socket, 15...Solder holding member, 17...Through hole

Claims (6)

[Claims] (1) In a method of soldering a printed circuit board and a member to be soldered at a single or multiple predetermined locations, at least the soldering involves a solder holder that holds the solder at the position necessary to connect the locations. A soldering method characterized in that soldering is performed by sandwiching a member between the printed circuit board and the member to be soldered. (2) The soldering method according to claim (1), wherein the solder holding member is constituted by an electrically insulating plate having one or more holes penetrating in the thickness direction for holding the solder. . (3) When soldering multiple parts,
The soldering method according to claim 2, wherein the soldering method is characterized by the diameter of the through hole rather than the distance between the parts. (4) When soldering multiple parts,
When the diameter of the through hole is set to a size that prevents molten solder from falling out, the soldering method according to claim 2 or 3, wherein the soldering is performed by heating the entire solder holding member. is the method. (5) When soldering multiple parts,
If the diameter of the through hole is large enough to allow molten solder to fall out, soldering should be done at the location. Claim No. 2 (2) which performs soldering by heating
) or (3) is the soldering method. (6) For parts other than the soldering parts of the printed circuit board,
Claim No. 1 covered with solder resist
) to (5), the soldering method described in item 1.