JPH01124288A - Semiconductor device - Google Patents

Abstract

PURPOSE:To prevent an air bubble from being generated between a wiring substrate and an electronic component mounted on it and to prevent insulating breakdown strength between lead terminals of the electronic component from being lowered by a method wherein a resin injection hole pierced along a direction from the surface to the rear is made in a position where the electronic component is to be mounted in the wiring substrate. CONSTITUTION:A resin injection hole 10 pierced along a direction from the surface to the rear is made in a position where an electronic component is to be mounted in a wiring substrate 1. e.g., in a position where a photocoupler 2 is to be mounted. Accordingly, the photocoupler 2, 8 resistor 3 and an extraction terminal 4 as electronic components are mounted individually on this wiring substrate 1; these are connected mutually by a soldering operation) after that, a resin 6 is coated on their whole surface; one part of the coated resin 6 passes through the resin injection hole 10 and flows into a space between the surface of the wiring substrate 1 and the rear surface of the photocoupler 2 from the rear side of the substrate; the resin 6 is filled between the surface of the wiring substrate 1 and the rear surface of the photocoupler 2 without generating an air bubble 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a semiconductor device, and more particularly to the structure of a semiconductor device including a wiring board that is externally sealed with resin.

(Prior Art) FIG. 2 is a cross-sectional view showing an example of a semiconductor device with a conventional structure.
A photocoupler as an electronic component mounted on the top, 3 a MELF resistor also as an electronic component, 4 a lead-out terminal arranged on the wiring board 1, and 5 a wiring pattern formed on the back surface of the wiring board (not shown). 6 is an epoxy resin for externally sealing the wiring board 1 on which the electronic components 2 and 3 are mounted. In addition, the code|symbol 7 in a figure is a bubble mentioned later.

In manufacturing this semiconductor device, cream solder 5 is first applied to the required locations on the wiring pattern of wiring board 1, and then photocoupler 2, Melf resistor 3 and A pullout terminal 4 is mounted on each. After that, these are heated together in a reflow oven to connect the wiring pattern and the lead terminals and pull-out terminals 4 of the electronic components 2.3 to each other by soldering, and then a resin 6 is applied to the entire surface of these parts to form an exterior. It is designed to be sealed.

[Problem that the invention seeks to solve]

By the way, in the semiconductor device having the above structure, since the distance between the surface of the wiring board 1 and the bottom surface of the photocoupler 2 mounted thereon is narrow, the applied resin 6 does not flow between the two, and residual air There is a problem in that air bubbles 7 are generated, and as a result, the dielectric strength between the primary lead terminal and the secondary lead terminal of the photocoupler 2 is reduced due to the air bubbles.

This invention was made to solve these problems, and it prevents the generation of air bubbles between the wiring board and the electronic components mounted thereon, and prevents the generation of air bubbles between the lead terminals of the electronic components. The present invention aims to provide a semiconductor device that can prevent a decrease in dielectric strength.

[Means for solving problems]

The present invention provides a semiconductor device formed by externally sealing a wiring board on which electronic components are mounted with a resin, in which a resin inflow hole is formed in the electronic component mounting position of the wiring board, passing through the wiring board along the front and back directions. It has the following characteristics.

[Function] According to the above configuration, a part of the applied resin flows from the back side of the wiring board between the front surface and the electronic component through the resin inflow hole penetrating along the front and back directions of the wiring board. Therefore, the generation of bubbles between the two is effectively prevented.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a sectional view of a semiconductor device showing the structure of an embodiment of the present invention. This semiconductor device is basically the same as the conventional example, and includes a wiring board 1, a photocoupler 2 and a Melf resistor 3 as electronic components mounted on the wiring board 1, and lead terminals arranged on the wiring board 1. 4, a wiring pattern (not shown) formed on the surface of this wiring board 1, and lead terminals and extraction terminals 4 of electronic components 2.3.
are connected to each other via cream solder 5, and then sealed with an epoxy resin 6.

In this embodiment, a resin inflow hole 10 is formed at the electronic component mounting position of the wiring board 1 in this embodiment, for example, at the mounting position of the photocoupler 2, which penetrates the wiring board 1 along the front and back directions.

Therefore, similarly to the conventional example, a photocoupler 2, a Melf resistor 3, and a lead-out terminal 4 as electronic components are mounted on this wiring board 1, and after these are connected to each other by soldering, a resin 6 is applied to the entire surface of these. Once coated, a portion of the coated resin 6 flows from the back side of the wiring board 1 through the resin inflow hole 10 between the front surface of the wiring board 1 and the bottom surface of the photocoupler 2 . Therefore, according to the structure of this embodiment, air bubbles 7 are not generated between the surface of the wiring board l and the bottom surface of the photocoupler 2, unlike in the conventional example, and the resin 6 is filled between the two. will be done.

In the above description, the electronic component mounted on the wiring board 1 is described as the photocoupler 2, but the invention is not limited to this, and the present invention can be applied even if the electronic component is another discrete element. Needless to say, it can be applied to obtain similar effects.

〔Effect of the invention〕

As explained above, according to the present invention, a resin inflow hole is formed in the electronic component mounting position of the wiring board, passing through it along the front and back directions, so that a part of the resin coated on the entire surface is removed. The resin flows from the back side of the wiring board through the resin inflow hole between the front surface and the electronic component.

Therefore, the generation of air bubbles between the wiring board and the electronic component mounted thereon is effectively prevented, and the dielectric strength between the lead terminals of the electronic component does not decrease and can be improved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a semiconductor device showing an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing an example of a semiconductor device having a conventional structure. In the figure, reference numeral 1 indicates a wiring board, 2 a photocoupler (electronic component), 6 a resin, and 10 a resin inflow hole. Note that the same reference numerals in the drawings indicate parts and portions that are the same or correspond to each other.

Claims (1)

[Claims] (1) In a semiconductor device formed by externally sealing a wiring board on which electronic components are mounted with a resin, a resin inflow hole is formed in the electronic component mounting position of the wiring board to penetrate along the front and back directions of the wiring board. Characteristic semiconductor devices.