Method of applying moisture-proof material to electrical parts

Abstract

To provide a method for applying a moisture-proof material to an electric component by which the moisture-proof material can be applied to a specific part in the periphery of an electric component body except the electric component body and a process can be simplified.SOLUTION: A method for applying a moisture-proof agent to an electrical component 200, in which a moisture-proof material 510 is applied around the electrical component 200 mounted on a substrate 100, includes a step of attaching a guide member 400 for guiding a flow of the moisture-proof material 510 to an outer peripheral portion of the electrical component 200 to an upper portion of the electrical component 200, a step of causing the moisture-proof material 510 to flow from above the guide member 400 toward the substrate 100, and a step of removing the guide member 400.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for applying a moisture-proof material to an electrical component, such as a coil, around the electrical component. [Background technology]

[0002] Generally, in circuits for in-vehicle equipment, a coil is used in the filter of the power supply circuit connected to the in-vehicle battery. By combining this coil with a capacitor to form a low-pass filter, the circuit is protected from impulse noise superimposed on the connection cable between the in-vehicle battery.

[0003] However, in many cases, coils mounted on a circuit board have lands for wiring that are exposed farther out than the coil body itself, and if condensation forms on these lands, it is likely to cause problems such as an increase in dark current. For this reason, measures are taken to coat such lands with moisture-proof material.

[0004] Conventionally, there has been known a method for manufacturing a high-frequency module in which masking is performed by combining hard and soft members to mask relatively thick components such as coils and apply moisture-proof material to required areas (see, for example, Patent Document 1). In this method, for thick components, openings are formed only in the soft member, and the thick component is entirely covered with the openings to perform masking. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-245947 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when applying the moisture-proofing material to the coil lands, it can also adhere to the coil body, which can cause defects, so it is desirable to apply the moisture-proofing material only to the lands. However, with the method described in Patent Document 1, the coil, which is a thick component, must be entirely masked, making it impossible to apply the moisture-proofing material only to the coil lands. Furthermore, the method described in Patent Document 1 requires a masking member made up of a combination of hard and soft members, and the entire board and component must be fixed to a clip member, making the process of applying the moisture-proofing material complicated.

[0007] The present invention has been created in consideration of the above points, and its object is to provide a method for applying a moisture-proof material to an electrical component, which can apply a moisture-proof material to specific areas around the electrical component, excluding the electrical component itself, and which can simplify the process. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the method for applying a moisture-proof material to an electrical component of the present invention is a method for applying a moisture-proof material to the periphery of an electrical component mounted on a substrate, and includes a first step of attaching a guide member to the top of the electrical component to guide the flow of the moisture-proof material to the periphery of the electrical component, a second step of flowing the moisture-proof material from above the guide member toward the substrate, and a third step of removing the guide member.Since the electrical component is covered with the guide member and the moisture-proof material flows along this guide member, it is possible to reliably apply the moisture-proof material to specific locations around the electrical component, excluding the electrical component itself.

[0009] Furthermore, it is desirable that the above-mentioned guide member is attached to the electrical component using a peeling adhesive. Because the guide member is attached to the top of the electrical component using a peeling adhesive, an attachment process using a separate member such as a fixing screw is not required, which simplifies the process.

[0010] Furthermore, the peeling adhesive is preferably an electrically peelable adhesive that can be peeled off by passing an electric current through it. Since the guide member can be easily removed by simply passing an electric current through it, the process can be further simplified.

[0011] Furthermore, it is desirable that the substrate has lands arranged in areas adjacent to the electrical components, so that even if lands used for bonding or other purposes are exposed around the electrical components, the moisture-proof material can be reliably applied only to these lands so as not to adhere to the electrical components.

[0012] It is also preferable that the surface of the guide member facing the electrical component is larger than the electrical component, thereby preventing the moisture-proof material from adhering to the electrical component.

[0013] Furthermore, it is desirable that the guide member has an inclined side surface that guides the moisture-proof material to the outer periphery of the electrical component, and that the moisture-proof material flows along this side surface, thereby enabling the moisture-proof material to be efficiently applied to the periphery of the electrical component. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 2 illustrates a circuit board according to an embodiment. [Figure 2] FIG. 10 is an explanatory diagram of a process for applying a moisture-proof material around an electrical component. [Figure 3] 10A and 10B are diagrams illustrating specific examples of guide members. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, a method for applying a moisture-proof material to an electrical component according to one embodiment of the present invention will be described with reference to the drawings.

[0016] FIG. 1 is a diagram illustrating a circuit board according to one embodiment. As shown in FIG. 1, an electrical component 200 is mounted on a substrate 100 by soldering or the like. This electrical component 200 is assumed to have a certain height, such as a coil constituting a noise filter. In addition, in an area 300 on the substrate 100 adjacent to the electrical component 200, a portion of a land 110 for wiring the electrical component 200 is exposed. In this embodiment, a moisture-proof material is applied to the area 300 including the land 110 so as not to come into contact with the electrical component 200.

[0017] FIG. 2 is an explanatory diagram of a process for applying a moisture-proof material to the periphery of the electrical component 200. As shown in FIG.

[0018] (Step 1) First, the substrate 100 on which the electric component 200 is mounted by soldering or the like is set in a predetermined position (FIG. 2(A)).

[0019] (Step 2) Next, a guide member 400 is attached to the top of the electrical component 200 ( FIG. 2(B) ). This guide member 400 guides the moisture-proof material dispensed from the top to the region 300 around the electrical component 200. The guide member 400 is fixed to the electrical component 200 using an electrically releasable adhesive 410. The electrically releasable adhesive 410 may be attached to the top of the electrical component 200 with the electrically releasable adhesive 410 attached to the bottom of the guide member 400. Alternatively, the electrically releasable adhesive 410 may be applied to the top of the electrical component 200 in advance, and the guide member 400 may be attached from above.

[0020] (Step 3) Next, moisture-proof material 510 is discharged toward guide member 400 from discharge port 500 arranged above guide member 400 (FIG. 2(C)). Guide member 400 has an inclined side surface 400A, and moisture-proof material 510 discharged from discharge port 500 is guided along this side surface 400A to the outer periphery of electrical component 200 and reaches region 300 on substrate 100.

[0021] FIG. 3 is a diagram showing a specific example of a guide member 400. FIG. 3 shows the shape of the guide member 400 as viewed from above (the side where the discharge port 500 is located). The guide member 400 shown in FIG. 3(A) has a quadrangular pyramid shape consisting of four side surfaces 400A. By discharging the moisture-proof material 510 from near the apex where the four side surfaces 400A intersect, the moisture-proof material 510 can be guided to the entire area 120 around the guide member 400. Furthermore, the guide member 400 shown in FIG. 3(B) has a roof shape consisting of two side surfaces 400A. By discharging the moisture-proof material 510 along the line where the two side surfaces 400A intersect, the moisture-proof material 510 can be guided to two specific locations 122 and 124 around the guide member 400.

[0022] (Step 4) After the application of the moisture-proof material 510 to the specific locations on the substrate 100 is complete, the voltage generator 600, which applies a predetermined voltage, is moved to connect the voltage application terminals 602 and 604 to the electrically peelable adhesive 410 ( FIG. 2(D) ). The electrically peelable adhesive 410 has a predetermined adhesive strength when not energized, but when energized, an electrochemical reaction occurs at the interface between the adhesive and the object to be bonded (electrical component 200), reducing the adhesive strength. Note that while FIG. 2(D) shows the positions of the terminals 602 and 604 as a simplified illustration, in practice, a voltage must be applied to cause such a reduction in adhesive strength, and the precise attachment positions of the terminals 602 and 604 must be determined. For example, the terminal 602 may be connected to an inductive member 400 made of a conductor, or the terminal 604 may be connected to an electrical component 200 covered by a metal housing.

[0023] (Step 5) Next, the voltage generator 600 is raised, and the voltage generator 600 is retracted upward together with the induction member 400, and the induction member 400 is removed from the electric component 200 (FIG. 2(E)).

[0024] As described above, in the method of applying moisture-proof material to the electrical component 200 of this embodiment, the electrical component 200 is covered from above with the guide member 400 and the moisture-proof material 510 flows along this guide member 400, so that the moisture-proof material 510 can be reliably applied to specific locations around the electrical component 200, excluding the electrical component 200 itself.

[0025] Furthermore, because guide member 400 is attached to the top of electrical component 200 using electrically peelable adhesive 410 (peeling adhesive), an attachment process using a separate member such as a fixing screw is not required, which simplifies the process. In particular, by using electrically peelable adhesive 410, guide member 400 can be easily removed simply by passing electricity through it, which further simplifies the process.

[0026] Furthermore, even when the land 110 used for bonding or the like is exposed around the electrical component 200, the moisture-proof material 510 can be reliably applied only to the land 110 so that the moisture-proof material 510 does not adhere to the electrical component 200.

[0027] Furthermore, by using guide member 400 whose surface facing electrical component 200 is larger than electrical component 200, it is possible to reliably prevent the moisture-proof material from adhering to electrical component 200. Furthermore, guide member 400 has inclined side surface 400A that guides moisture-proof material 510 to the outer periphery of electrical component 200. Therefore, moisture-proof material 510 flows along side surface 400A, and can be efficiently applied to the periphery of electrical component 200.

[0028] The present invention is not limited to the above embodiment, and various modifications are possible within the scope of the present invention. In the above embodiment, guide member 400 shown in Fig. 3 has a rectangular shape when viewed from above, but this is to match the shape of electrical component 200. If electrical component 200 has another shape, such as a cylindrical shape or a triangular prism shape, the shape of guide member 400 may be changed to match the shape of electrical component 200.

[0029] In the above-described embodiment, the guide member 400 is attached and fixed to the electrical component 200 using the electrically peelable adhesive 410. However, other peeling adhesives may be used. In such cases, step 5 shown in FIG. 2(E) may be performed using a tool that satisfies the conditions necessary for peeling. For example, the guide member 400 may be removed by applying a tensile load or by heating. [Industrial Applicability]

[0030] As described above, according to the present invention, the electrical component is covered with a guide member and the moisture-proof material flows along this guide member, so that the moisture-proof material can be reliably applied to specific locations around the electrical component, excluding the electrical component itself. [Explanation of symbols]

[0031] 100 boards 200 Electrical Components 110 rand 400 Guiding member 410 Electrically peelable adhesive 500 outlet 510 Moisture-proof material 600 Voltage Converter 602, 604 terminals

Claims

1. A moisture-proofing agent application method for electrical components, which applies a moisture-proofing material to the periphery of an electrical component mounted on a substrate, comprising: a first step of attaching a guide member to an upper portion of the electrical component to guide a flow of the moisture-proof material to an outer periphery of the electrical component; a second step of flowing a moisture-proof material from above the guide member toward the substrate; a third step of removing the guide member; A moisture-proof material coating method for electrical components, comprising:

2. 2. The method for applying a moisture-proof material to an electrical part according to claim 1, wherein the guide member is attached to the electrical part using a peeling adhesive.

3. 3. The moisture-proof coating method for electrical parts according to claim 2, wherein the peeling adhesive is an electrically peelable adhesive that can be peeled off by passing an electric current through it.

4. 2. The method for applying a moisture-proof material to an electrical component according to claim 1, wherein a land is disposed on the substrate in an area adjacent to the electrical component.

5. 2. The method for applying a moisture-proof material to an electrical component according to claim 1, wherein the guide member has a surface facing the electrical component that is larger than the electrical component.

6. 2. The method for applying moisture-proof material to an electrical component according to claim 1, wherein the guide member has an inclined side surface that guides the moisture-proof material to the outer periphery of the electrical component, and the moisture-proof material flows along the side surface.

Images