JPS5832488A - Printed circuit board device - 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 The present invention relates to a printed wiring board in which electrodes of electronic components such as chip resistors and flat integrated circuits are placed on lands made of conductive foil of the printed wiring board and soldered. Regarding the device, the amount of solder attached to the connecting lands is made uniform in advance to prevent short circuits between adjacent lands.

Surface-mount printing in which electronic components such as chip resistors and flat-punk integrated circuits are mounted on a printed wiring board, and the electrodes of the electronic components are bonded to connection lands and soldered. Conventionally, in a wiring board device, as shown in FIG. 1, solder is applied to the connecting land 2 of a printed wiring board 1 in advance by the depth method, and an electronic component 3 is mounted in this solder-resistant state. As shown in FIG. 2, the electrode 4 of No. 3 is pressurized by a heater block 5 to melt the solder 6 and solder the electrode 4 to the land 2.

Conventionally, a dip method as shown in FIG. 3 has been used to apply solder 6 to the lands 2 of the printed wiring board 1 in advance. That is, the solder 6 is attached to the lands 2 by moving the printed wiring board 1 in the direction of the arrow with the foil-conducting side of the printed wiring board 1 facing the solder spouting part 7 of the solder tank. 2 are placed close together, the 3rd
When the printed wiring board 1 is moved in the direction of the arrow as shown in (,) in the figure, 1. A phenomenon as shown in FIGS. 3(b) and 3(c) occurs on each land 2 that enters the solder spouting portion 7.

That is, in each land 2a, 2b, 2c, etc. that rushes into the solder spouting portion 7 due to the movement of the printed wiring board 1, the land that rushes into the solder spouting portion 7 following the preceding land. 2b, 2c..., the solder is in a thin wet state due to the preceding lands, so the solder spouting part 7
Those lands 2b, 2C...
... is Handa eb.

6C... adheres thinly and uniformly, but on land 2a, where there is no preceding land, there is nothing to pull the spouted solder thinly, so the solder is applied very thickly to land 2a. 6a is adhered.

If the solder 6a is thickly adhered to the land 2a in this way, when the electrode 4 of the electronic component 43 is soldered using the heater block 6, the molten solder flows out toward the land 2b and the land 2a
A disadvantage arises in that a and 2b are short-circuited.

The present invention provides a printed wiring board device which eliminates such conventional drawbacks, and one embodiment thereof will be described below with reference to FIGS. 4 and 6.

4 and 6, the same components as those of the conventional printed wiring board shown in FIGS. Lands 2a, 2b, 2c for connecting electronic components formed by
In addition to . . . , a dummy land 8 that first enters the solder spouting portion 7 is formed on the outside of the land 2a.゛The above-mentioned simulated land 8 enters the solder spouting portion 7 before the land 2a, and contacts the electronic component 3.

It is unrelated to the sequel.

By providing the simulated land 8 in this way, when the printed wiring board 1 is moved in the direction of the arrow as shown in FIG. The solders 6a, eb, 6c...
・When melted, solder does not protrude and short circuits between lands are prevented.

Note that the solder 9 adhered to the simulated land 8 is not melted because it is not related to the connection of electronic components.

The dummy land 8 may be provided independently or may be divided into parts for soldering by a solder resist, for example, in a foil-conducting portion that is integrated with the land 2a.

6 peni・ Further, the number of lands for connecting electronic components may be one.

As described above, the present invention provides a printed wiring board with a land made of conductive foil for connecting electronic components, and according to this, when making solder adhere to the land, a simulated land is used for connecting electronic components. The solder adheres to the lands evenly and in an appropriate amount, so when connecting electronic components, even if the solder on the lands melts, it will not protrude too much and cause a short circuit between the lands, resulting in good quality. A stable printed wiring board device can be obtained with this method, and the effect is great.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a state before mounting an electronic component on a conventional printed wiring board, Fig. 2 is a schematic diagram showing a state of connection of electrodes of the electronic part, and Fig. 3 (b). (C) is a diagram illustrating the solder adhesion process to the land of a conventional printed wiring board, FIG. 4 is a top view of the printed wiring board according to an embodiment of the present invention, and FIG. 6 is a diagram showing the solder adhesion process to the land of the conventional printed wiring board. It is a figure showing a state. 1...Printed wiring board, 2.2a, 2b, 2c
...Land, 3...Electronic parts: 4...
... Electrode, 6, 6 a, 6 b, 6 c
, 9-------- solder, ?・---Solder spouting part, 8...Mock land.

Claims (1)

[Claims] A land made of conductive foil for connecting electronic components is provided on the printed wiring board, and a dummy land is provided near the land to cause the solder to flow into the solder spouting portion in advance of the land. Printed wiring board equipment.