JPS59112700A - Waterproof device for printed 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] Industrial Application Field - The present invention relates to a waterproofing device 7 for printed circuit boards, for example,
The present invention relates to something that can be suitably applied when an electronic controller is mounted on a machine, an automobile, or the like.

9 is an example of the previous configuration and its problems.As shown in Figure 1, an electronic controller is mounted on a washing machine.
) and after FC, the entire printed circuit board (1) including the terminals (3) of the electronic components is completely coated with resin ■ by dipping it in solvent-type acrylic resin ■ that has been given thixotropic properties. As shown in Fig. 2, insert the mounting screw (6) into the mounting boss (6) provided at the top mark (presentation case) (51) of the washing machine through the mounting hole (small) provided on the printed circuit board (1). 7) is fixed. However,
As shown in Figure 1, in order to coat the entire printed circuit board (1) including the terminals (J edges) of electronic components with resin ■, a solvent-based acrylic resin Q
), the viscosity was as high as 23 poise, and if it was dried immediately after dipping, the solvent would foam and form pinholes, so it had to be left at room temperature for a long time and then force-dried. For this reason, automation was a necessity, and mass production was impossible. In addition, the terminals of electronic components (
31 has a thin resin (2) film of around 20 μm formed on it, and because this is soft, it can cause defects such as peeling if it is rubbed against an object while being installed in a washer, and furthermore, because it is a solvent type. If viscosity control is necessary or the work environment is unfavorable, 1γ problems may occur. In addition, due to the high viscosity, it is difficult to coat by controlling the liquid level, which makes it difficult to mount a switch with moving parts, and it is necessary to use an expensive reed switch for non-1'H side materials. There was also.

OBJECTS OF THE INVENTION In view of the conventional problems, the present invention can ensure mass productivity and high quality, and can easily achieve a liquid level of t++l ta, eliminating any limitations on implementation! The purpose of the present invention is to provide a waterproofing device for a printed circuit board that can be easily removed.

Structure of the Invention In order to achieve this object, the present invention arranges a printed circuit board on which electronic components are mounted inside a case whose negative side is open, and the case has mounting holes provided in the printed circuit board. A boss part is provided in which the tip part passes through and the base part engages with the printed circuit board A), and a through hole is provided in this boss part through which the mounting screw passes; To provide a waterproof device for a printed circuit board filled with a waterproof filler in which at least a conductor part of an electronic component is embedded.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 3 to 5. (8) is a case made of plastic molded product, with a movable bush switch 00% LED inside.
(Light Emitting Element) [111] A printed circuit board (1) on which electronic components such as a microcomputer and the like are mounted is arranged. This printed circuit board (1) is provided in the case (g) protruding from the bottom surface, and is provided with four bosses (9) so as not to contact the bottom surface of the case 8, and at least as far as possible between the printed circuit board (1) and the electronic components. The conductor portion is supported so as not to protrude beyond the opening end of the case. That is, the tip of the boss (9) is formed with a smaller diameter than the mounting hole (4) of the printed circuit board (1) and passes through the mounting hole (4), and the base is larger than the mounting hole (4). It is formed to have a diameter and is formed to engage with the printed circuit board (1). Also, this boss (9) has a printed circuit board (1).
A through hole (9a) is formed through which the screw (7) passes through. In the case (1) in which the printed circuit board (1) is housed and supported in this way, a waterproof filler (13) such as waterproof resin, hot melt, wax, etc. is filled and hardened, as shown in Figure 4. The printed circuit board (1) Oishima It (mounted) is mounted in this waterproof i raw filling phase f131.b, at least the conductor part of the child component is embedded.
As shown in Fig. 5, the printed circuit board (1) waterproofed with the waterproof filler (13) is attached to the top mark (decorative box) (5) of the first A'ζAω and the boss for mounting the base. (6) is fixed with the mounting screw (7). In other words, the boss (9) of the case (8) is brought into contact with the mounting boss (6), and the boss ■
) The printed circuit board (1) is mounted by screwing a mounting screw (71) consisting of a tapping screw into the mounting boss (6) through the through hole (9a).

If the printed circuit board (1) is attached in this way, water will not get into the top mark (vanity box) (5) of the machine or condensation will occur if it is used in a high humidity atmosphere such as a bathroom. Even if the electronic controller malfunctions or
Breakdowns can be completely prevented, and tL stability can be ensured with less equipment use.

Effects of the Invention According to the printed circuit board waterproofing device of the present invention, as is clear from the above description, at least the conductor portions of the printed circuit board and electronic components mounted thereon are completely waterproofed by the case and the waterproof filler. In addition, it eliminates resin constraints such as complicated coating methods to prevent pinholes, curing conditions, chikuntorobic properties, pot life, and low viscosity, and allows for high quality and mass production through automation. In addition, by manually metering and injecting the waterproof filler, liquid level control becomes easy, and there is no need to mask bush switches or LEDs (light emitting elements) that have OT moving parts, which significantly reduces costs overall. It is possible to reduce the

[Brief explanation of drawings]

Figures 1 and 2 show conventional examples;
The figure is a sectional view of the installed state, Figures 3 to 5 show the 71IQ V/jl, which is a part of the present invention, and Figure 3 shows the printed circuit board placed inside the case. - Figure 4 is a perspective view with a part of the side cut out, a longitudinal sectional front view, and a cross-sectional view of the M51 seat 1 installed. (1) is printed circuit board, μ) is mounting hole, (81 case, (9) is boss, (9a) LD through hole, (In+ is waterproof optical filler material. Patent attorney Yamaki) Takashi) I La No L and 1 City 2 Figure 3 ・ 4th tlJ

Claims (1)

[Claims] A printed circuit board with a 1% sub-component mounted thereon is placed inside a case with an open opening, and the tip part passes through the mounting hole provided on the printed circuit board, and the base part engages with this printed circuit board. a waterproof filler for embedding at least a conductor portion of the electronic component mounted on the printed circuit board in the case, by providing a boss portion that meets the user, and providing through holes in the boss portion for receiving four mounting screws; Waterproof coating M0 for printed circuit board filled with