JPS62136097A - Method of attaching parts to printed wiring 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 attaching components to a printed wiring board used in electronic equipment and the like.

Traditional technique? :I'7 In recent years, reflow soldering has been increasingly used as a method for attaching components to printed wiring boards in order to make electronic devices smaller and thinner.

In the reflow soldering method, cream solder is applied to the soldering land of the printed wiring board, and then the component is mounted so that the electrode corresponds to the soldering land, and the component is heated to melt the cream solder. In this method, the electrodes of the device are connected to the copper foil of the soldered land of the printed circuit board to form the circuit of the device. Since heating in this reflow soldering method is performed at a high temperature and for a long time, the copper foil surface of the soldering land of the component will be oxidized in retrofitting, and solderability will be impaired. In order to remove this factor that inhibits solderability, the entire soldering land of a printed wiring board is coated with preflux or chemical treatments such as glycoat treatment are performed.

For retrofitting, IJ-mu solder is applied to the entire soldering land of the component, and the copper foil surface of the land is plated with solder by heating and melting (9) to improve solderability.

Problems to be solved by the invention However, even if such preflux and glycoat treatments are performed, it is difficult to control the elapsed time after application, the temperature and time of preheating in the heating process, and the heating temperature and time of the solder melting pot. Due to variations in soldering properties, it is difficult to fully demonstrate the effect, and the first retrofitting has the problem that the soldering surface of the soldering land of the component oxidizes, making it impossible to ensure soldering quality. In addition, in the retrofitting method, the copper foil surface of the solder land is solder-plated by applying cream solder to the entire soldering land of the component and heating and melting it.
If the amount of cream solder is large and cannot be applied to the entire soldering land, the retrofitting inside the soldering land will block the lead insertion hole of the component with solder, and the retrofitting will have the problem that the lead of the component cannot be inserted. Ta.

The present invention solves these conventional problems.
To provide an excellent method for attaching components to a printed wiring board, which is capable of attaching components to the printed wiring board by a reflow soldering method and improving the soldering quality of components that are subsequently attached by a dip method or manual soldering. It is something.

Means for Solving the Problems The method of attaching components to a printed wiring board according to the present invention: Reflow soldering is applied to a part of the soldering land of the component after it is attached: Apply cream solder, and then heat it. ,
The solder layer is melted and formed on the soldering land, and in the subsequent process, the lead of the component is inserted into the soldering land and attached using the dip method or manual soldering. It is.

Function: Method of attaching components to a printed wiring board according to the present invention: Parts to be attached to the printed wiring board by reflow soldering method and parts to be attached later by inserting component leads into the printed wiring board by dip method or manual soldering. Reflow soldering is an attachment method that is installed later.Retrofitting is a process in which cream solder applied to a part of the soldering land of a component is heated and melted, so that it can be attached later without blocking the lead insertion hole of the component. Retrofitting involves forming a solder layer over the entire soldering land of the component, and then attaching the component. Retrofitting prevents oxidation of the soldering land of the component.
Retrofitting improves the soldering quality during the process.

Embodiment FIG. 1 shows an embodiment of the present invention, and FIG. 2 shows a sectional view thereof.

In this embodiment, cream solder 4a and 4b are first applied to the component soldering lands 2 on the blunt wiring board 1 and the component soldering lands 3 for later installation at j4 in FIG. 1a and FIG. 2b. At this time, cream solder 4b is applied on the soldering land 3 of the component in a well-balanced manner and partially on the soldering land 3 of the component in the retrofitting. Next, the component 6 is mounted as shown in FIGS. 1 and 2, heated and melted, and the component 5 is soldered to the component soldering land 2. At the same time, as shown in FIGS. 1a and 2a, the cream solder 4b is applied at a well-balanced position on the soldering land 3 of the component overall and partially, and the retrofitting is performed on the soldering land 3 of the component. Since the dragon of the cream solder 4b on the soldering land 3 is a sunset scene, the cream solder 4b is heated to
As shown in Figure bO, the retrofit spreads thinly over the entire soldering land 3 of the component. Therefore, the solder layer 7 can be formed afterward without blocking the lead insertion hole 6 of the component, and oxidation can be prevented and the soldering quality can be improved. Thereafter, as shown in FIGS. 1C and 2C, the retrofitted component 8 is inserted into the lead insertion hole 6 of the retrofitted component and soldered using the dip method or manual soldering.

In addition, it goes without saying that it is possible to improve the soldering quality by changing the shape and size of the soldering land 3 of the component (as well as the position, shape, and amount of cream solder applied) in retrofitting. do not have.

Effects of the Invention The present invention is a method for attaching components to a printed wiring board using a reflow soldering land and components to be attached later by a dip method or manual soldering by inserting a component lead into the printed wiring board. Soldering is installed later. For retrofitting, apply cream solder to a part of the soldering land of the component, then heat and melt it to apply a layer of solder over the entire soldering land without blocking the lead insertion hole of the component. By forming, retrofitting can realize an excellent method for attaching components to a printed wiring board, which can improve the soldering quality in the process.

[Brief explanation of drawings]

Figures 1a, b, and c are plan views for explaining the steps of a method for attaching components to a printed wiring board in an embodiment of the present invention;
Figures 2a, b, and c are cross-sectional views for explaining the steps of the method. 1...Printed wiring board, 2...Component soldering land, 3...Retrofitted component soldering land,
4a. 4b... Cream solder, 5... Parts,
6... Retrofitted parts lead insertion hole, 7...
Solder layer, 8... Retrofitted parts, 9... Copper foil 110... Resist ink. Name of agent: Toshihiro Nakao and 1 other person/-
-- Blue l/l- Shirootou Fu Shimo Kari 2 --- Kato et al. Senda what = T, Do J.
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4-. 4b --- Cree-t, +'s 5-11 Section Item 6-11 Kaiii I7 Japanese Ancient 5 Gods) Jノ (α) 7 --- Senda/! 1
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Claims (1)

[Claims] A method of attaching parts to a printed wiring board by reflow soldering and parts that are subsequently attached by inserting component leads into the printed wiring board by dip method or manual soldering, and which are retrofitted parts that are attached after reflow soldering. A print characterized by applying cream solder to a part of the soldering land, then heating and melting it to form a solder layer on the soldering land, and attaching retrofit parts to the soldering land in a later process. How to attach parts to a wiring board.