JPS61168289A - Electric part mounted printed circuit board and manufacture thereof - 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 printed circuit board in which non-heat resistant military and gas components are mounted on the printed circuit board using solder applied by immersion in a solder bath, and its manufacture. Regarding the method.

[Conventional technology]

Generally, to mount electrical components on a printed circuit board, the method disclosed in Japanese Utility Model Publication No. 57-26379 is used, in which the electrical components are temporarily fixed onto the printed circuit board with adhesive, and then immersed in a solder bath to be soldered. It will be done.

That is, as shown in FIGS. 3 and 4, copper foil patterns (7) (8) and solder resist layers (9) are formed on the printed circuit board (1), respectively, and the caps (4) of the electrical components (4) are formed. 2) Pattern electrodes such as (3) (7) (8)
The electrode lands [alpha]])02 are pasted with adhesive (6) and temporarily fixed.

Next, the printed circuit board (1) with the electrical components (4) temporarily attached to it.
are immersed in a solder bath and soldered to the electrode lands αυα of the caps (2), (3), etc., so that the circuit components (4) are mounted on the printed circuit board (1) with sufficient electrical and mechanical strength. It is a means to ensure that it is implemented in

In addition, in cases where electrical components are mounted on both sides of a printed circuit board for high-density mounting, electrical components with lead wires are mounted on one component side of the printed circuit board, and electrical components are also mounted on the patterned surface on the opposite side. With a hybrid mounting method that implements
The means described in Japanese Patent Application No. 58-68172 is known.

This means uses a so-called two-dip method in which parts with lead wires are dipped into a solder bath and soldered on a printed circuit board, and then electrical parts are dipped into a solder bath and soldered.

That is, in this method, as illustrated in FIGS. 5(A) to 0), before the first immersion in the solder bath,
As shown in A), parts other than land 0 with lead wires to be soldered for the first time (including the parts insertion holes for electrical parts lands and retrofits such as switches, lamps, jacks, etc.) A masking material α0 for shielding is attached to the printed circuit board (1) in advance. Next, in Figure 5)
As shown in the figure, electrical components with lead wires are inserted and soldered by first immersion in a solder bath.

Next, remove the masking material), temporarily fasten the electrical components to the lands to which no solder is attached, and perform a second solder bath immersion to complete the soldering as shown in Figure 5). It is something.

By using the masking material in this way, it is possible to prevent solder from adhering to the land of the component, creating a gap between the raised land copper foil surface and the electrical component, and causing soldering defects. It has been known.

However, the above-mentioned conventional means can be implemented for heat-resistant electrical components that can withstand high temperatures during immersion in a solder bath.

Therefore, when mounting non-heat resistant electrical components (such as ICs) on a printed circuit board (), it is not possible to immerse each electrical component in a soldering iron. Ta.

Alternatively, cream solder was applied to the lands of the printed circuit board, electrical components were mounted on this, and soldering was performed at low temperatures.

[Problem that the invention seeks to solve]

When mounting non-heat resistant electrical components on a printed circuit board, if each non-heat resistant electrical component was soldered using a soldering iron, the work would be complicated and inefficient, resulting in low productivity and high prices. There is a problem. Furthermore, the quality is unstable, soldering requires skill, and it is difficult to respond to fluctuations in production volume.

Furthermore, the method using cream solder also requires a cream solder supplying machine for supplying cream solder to the land portions of the printed circuit board, and there is a problem in that the reliability of this dispenser is low. Furthermore, the quality of the cream solder becomes unstable due to aging, and the heating method is difficult as solder balls form during heating, and the cream solder itself is expensive.

In view of the above-mentioned points, the present invention aims to provide a new printed circuit board and its manufacturing method (q) in which non-heat resistant electrical components are soldered and mounted using solder applied to lands by immersion in a solder bath. purpose.

[Failure to solve the problem]

The printed circuit board on which the electrical component of the present invention is mounted has a land α
Solder α is applied to a predetermined part of η by dipping in a solder bath.
It is characterized in that it is locally heated and soldered to and mounted on a non-heat resistant electrical component (4).

In addition, a printed circuit board (1) on which this electrical component (4) is mounted is also provided.
) includes a step of attaching a masking material α0 to a predetermined portion of each land 0η on which a non-heat resistant electric component (4) is mounted on a printed circuit board (1), and a process of attaching a masking material α0 to a predetermined portion of each land 0η on which a non-heat-resistant electric component (4) is mounted on a printed circuit board (1), and During the process of immersing the board (1) in a solder bath and applying solder 01 to the portions of each land aη to which the masking material α→ is not attached, a non-heat-resistant electrical conductor is placed at a predetermined position on the descendant land αY after removing the masking material α0. The present invention is characterized by the step of mounting the component (4) and locally heating the solder 06 which has been applied to each land Ql by solder dipping to solder the non-heat resistant electrical component (4).

[Effect]

As mentioned above, electrical components are soldered and mounted on a printed circuit board using solder applied to the solder by immersion in a solder bath. is obtained. Furthermore, solder can be applied to the desired portion of the land by simply applying masking material to the desired portion of the land on the printed circuit board and dipping it in a solder bath, making the overall manufacturing process simple and easy. has.

〔Example〕

Hereinafter, an embodiment of a printed circuit board on which electrical components of the present invention are mounted and a method for manufacturing the same will be explained with reference to FIGS. 1(A) to (E). )
2, parts corresponding to those in FIGS. 3 to 5 are given the same reference numerals for convenience of explanation.

FIG. 1(A) is a perspective view showing the original board of a printed circuit board (1), in which a plurality of lands α■ for soldering non-heat-resistant electrical components (4) are installed at predetermined locations.

This printed circuit board (1) is placed in a predetermined position with masking material αυ during the masking material αυ printing process shown in the process diagram in Figure 2.
Print and adhere. Note that this work may be performed by an automatic machine during the substrate manufacturing process.

As shown in Figure 1 (B), this masking material αυ is used to shield the part of each land 0■ on which the electrical component (4) is placed, and especially when there are multiple lands αη, The masking material αυ that shields the masking material αυ is made to be continuous and integrated, and when removing the masking material α, by pulling one end of the masking material αυ, the entire masking material αυ can be easily peeled off at once.

Furthermore, in this example, the masking material (1→
Since it is printed and adhered to 1), its positional accuracy can be set extremely accurately, and the soldering of the electrical component (4) can be performed accurately and reliably, thereby improving quality.

Next, when heat-resistant chip components are also mounted on this printed circuit board (1), predetermined electrical components are temporarily fastened to the printed circuit board (1) in the step of temporarily fastening heat-sensitive electrical components shown in Figure 2. do. Then, in the next solder bath dipping step, this printed circuit board (1) is immersed in a solder bath to solder the heat-resistant electrical components (4), and also to form a land α°C for mounting the non-heat-resistant electrical components (4). Solder aQ is applied to the part where the masking material α is not attached. Therefore, in retrofitting, the supply of solder to the parts pool is processed at the same time in this process, which can improve productivity.

Furthermore, the printed circuit board (
1) Peel off the masking material (G). Note that in this operation, as mentioned above, since the masking material (g) is continuous and integral, the entire masking material can be easily peeled off by just pulling a part of it.

After removing this masking material (G), the printed circuit board (
As the main part of 1) is shown in Figure 1 (C), each land α■
Solder αQ is piled up at a predetermined portion of the solder, and each land α and the portion on which the electrical components are placed are in a clean state.

Therefore, it is possible to proceed with the work without cleaning the residue of slacks and the like when the printed circuit board (1) is immersed in the solder bath in the above-described process.

In the next temporary fixing process for non-heat-resistant electrical components, as shown in ) in Figure 1, non-heat-resistant chip components are placed on the parts of each land 0]) that are not covered with solder, and temporarily attached with adhesive. fasten. Furthermore, since the electrical component (4) is placed directly on the land α on which no solder is applied, the component can be mounted at the same height as the board surface. Note that it is of course possible to solder leadless components such as tapless coils.

Next, in the local heating soldering process shown in Figure 2, each land αη
The solder αQ placed in
) to the cap terminal (2) and finish the work. The work of melting the solder αO piled up at important points on such a flat printed circuit board (1) is suitable for local heating work, and the work is easy.

In this way, the solder cL applied by immersion in the solder bath
Since O) is soldered by local heating, there is no need to use cream solder, and soldering can improve the electrical characteristics of the part and has sufficient mechanical strength to connect electrical parts to printed circuit boards. (1) Above f10) can be implemented. Furthermore, since heat-resistant and non-heat-resistant electrical components can be mounted in a mixed manner, the range of applications of the printed circuit board can be expanded.

〔Effect of the invention〕

As described in detail above, according to the printed circuit board on which the electrical components of the present invention are mounted, the non-heat resistant electrical components are soldered using general solder that is dipped in a solder bath and applied. It is possible to improve mechanical properties and ensure sufficient mechanical strength.

Furthermore, according to the manufacturing method of the present invention, solder is immersed in the solder bath while the required portions of the land, etc. are shielded by the masking material, and solder can be applied to the required portions of the land, making the work easy and accurate. Moreover, since the area that was shielded with masking material is clean, it is possible to simplify the work process and improve work efficiency by omitting the work of cleaning the area where non-heat-resistant electrical components are mounted.

[Brief explanation of drawings]

Figures 1 (4) to 0) are explanatory diagrams of each manufacturing process showing an example of a printed circuit board on which the electrical components of the present invention are mounted and a method of manufacturing the same, Figure 2 is a process diagram of the manufacturing method, and Figure 3 4 is a perspective view showing an example of conventional electrical component mounting, FIG. 4 is a sectional view taken along the line Vl-Vl in FIG. It is a manufacturing process explanatory diagram shown. (1) is a printed circuit board, (4) is an electrical component, and 01) is a land and an α re-masking material. Figure 8Xπ Figure 4

Claims (1)

[Scope of Claims] 1. A non-heat resistant electrical component is soldered and mounted by locally heating solder that has been applied by dipping in a solder bath to a predetermined portion of the land where no masking material is attached. A printed circuit board with electrical components mounted on it. 2. A step of attaching a masking material to a predetermined portion of the land of the printed circuit board where the non-heat resistant electrical component is mounted, and immersing the printed circuit board with the masking material attached in a solder bath to remove the masking material on the land. Mounting the non-heat resistant electrical component on the portion of the printed circuit board from which the masking material has been removed, and locally heating the solder that has been immersed in the solder on the land, 1. A method for manufacturing a printed circuit board on which electrical components are mounted, the method comprising the step of soldering the components to the lands.