JP2503665Y2 - Printed wiring board for surface mounting - Google Patents

Description

[Detailed Description of the Invention] [Industrial application] The present invention relates to a printed wiring board on which surface mount components are mounted, and in particular, the wiring pattern is peeled off by thermal shock during mounting or mechanical shock after mounting. The present invention relates to a difficult-to-use surface mounted printed wiring board.

[Prior Art] Conventionally, a surface-mounted printed wiring board of this type has generally been constructed as shown in FIG.

That is, a wiring pattern 11 on which a required circuit is printed is adhered to the surface of the substrate body 10.
The surface-mounting component 12 was mounted on 11 and the component electrode 12a derived from the surface-mounting component 12 was coated with solder 13 so as to be fixed on the substrate body 10.

[Problems to be Solved] As described above, the conventional surface-mounted printed wiring board is merely fixed by mounting components on the surface and soldering. For this reason, the adhesive strength between the board body and the mounted component largely depends on the degree of adhesion between the wiring pattern and the board body. However, the adhesive strength of this adhesive surface is apt to deteriorate due to thermal shock during soldering, and it is mechanically brittle.

In recent years, surface mounting components have become different in shape and larger in size due to the progress of their development, and there are increasing opportunities to mount these components also on wiring boards. When soldering a large-sized component in this way, the thermal shock is stronger than before, so that the adhesive surface of the wiring pattern deteriorates more quickly. For this reason, in the worst case, the wiring pattern may be peeled off from the substrate body, which requires mounting.

Further, even after mounting, since the components are large, the mechanical impact due to a drop or the like is large, so that the wiring pattern is often peeled off from the substrate body.

The present invention has been made in view of the above problems, and provides a printed wiring board for surface mounting, which can prevent peeling of a wiring pattern due to thermal shock or drop shock when soldering surface mounting components. With the goal.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides a printed wiring board for surface mounting, in which a wiring pattern is formed on the board body, and retains at a required portion of the board body at a rear surface protruding portion. A through hole for preventing pattern peeling having a flange portion is provided, and the wiring pattern is introduced into the through hole.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall perspective view of a surface mounting printed wiring board according to a first embodiment of the present invention, and FIG. 2 is a side sectional view of the same.

In the drawing, 1 is a substrate body, and a wiring pattern 2 is adhered to the surface thereof. 2a is a component mounting pattern, which is formed on a part of the wiring pattern 2. In this embodiment, the push switch 4 is soldered to the component mounting pattern 2a as a surface mounting component. When the push switch 4 is turned on / off, an external force acts in the direction of the arrow a in the figure, and this external force acts on the component mounting pattern 2a or the wiring pattern 2.

Therefore, in this embodiment, the through hole 3 is formed in the portion of the board body 1 located in the vicinity of the component mounting pattern 2a and in the acting direction of the external force (direction of arrow a), and the through hole 3 of the board body A flange 3a for preventing slipping out is formed on a portion protruding from the back surface.

By introducing the wiring pattern 2 into the through hole 3, the adhesive strength against external force is increased.

In this embodiment, the resist 5 is applied to the wiring pattern 2 (excluding the component mounting pattern 2a) and the upper surface of the substrate body 1 to prevent the wiring pattern 2 from peeling off.

FIG. 3 shows a second embodiment of the present invention, and the same parts as those in FIG. 1 are designated by the same reference numerals.

In this embodiment, a through hole 3 is formed in a portion of the substrate body 1 to which the component mounting pattern 2a is adhered, the component mounting pattern 2a is introduced into the through hole 3, and the surface mounting component 4 is soldered. 6 is made to flow into the through hole 3.

In the above-described first embodiment, since the surface of the through hole 3 is blocked by the resist, the solder does not flow in. However, by flowing the solder into the through hole 3 as in the present embodiment, the wiring is further strengthened. The pattern 2 (including the component mounting pattern 2a) can be adhered to the substrate body 1.

[Effects of the Invention] As described above, according to the present invention, the fixing strength of the wiring board is improved without adding other mechanical parts, and the pattern is peeled off even by thermal shock or drop shock during soldering. There is an effect that can prevent.

In particular, since the flange is formed in the portion of the through hole protruding from the back surface of the substrate body, the pattern peeling can be prevented more reliably.

[Brief description of drawings]

FIG. 1 is an overall perspective view of a surface mounting printed wiring board according to a first embodiment of the present invention, FIG. 2 is a side sectional view of the same, and FIG. 3 is a front sectional view showing a first embodiment of the present invention. FIG. 4 is a front sectional view showing a conventional surface-mounted printed wiring board. 1: Board body 2: Wiring pattern, 2a: Component mounting pattern 3: Through hole, 4: Surface mounting component 5: Resist, 6: Solder

Claims (1)

(57) [Scope of utility model registration request] 1. A printed wiring board for surface mounting, wherein a wiring pattern is formed on a substrate body, and a through hole for preventing pattern peeling, wherein a retaining flange portion is formed on a rear surface protruding portion at a required portion of the substrate body. And a printed wiring board for surface mounting, wherein the wiring pattern is introduced into the through hole.