JP2007194451A - Electronic component and its mounting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively provide an electronic component and the mounting method of the same whose lead is insulated surely, and which will not require additional machining work while being excellent in working efficiency. <P>SOLUTION: The electronic component is provided with an insulation coating 22 attached to a substrate 20 by the lead 18 and consisting of an insulation coating material capable of being molten by heat upon soldering. The insulation coating 22 covers at least the whole of the lead 18 on a part exposed from the substrate 20 with the lead 18 attached thereto. The insulation coating 22 consists of polyurethane, polyamide, enamel, polyurethane nylon or enamel nylon. The lead 18 is inserted to the substrate 20 under a state that the insulation coating 22 is applied to solder the same whereby the insulation coating 22 is removed from the soldered part of the lead 18 and electric connection is accomplished. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electronic component that is attached to a circuit board by a lead that is a metal conductive terminal and a mounting method thereof.

  2. Description of the Related Art Conventionally, some electronic components mounted on a circuit board of an electronic device are soldered by inserting a lead into a mounting hole of the circuit board, such as a power transistor. Such electronic components are forcibly air-cooled by blowing outside air with a fan in order to absorb the heat generated by the components and stabilize the operation. In this case, dust or the like contained in the air introduced from the outside may adhere to the substrate or the electronic component attached to the surface and accumulate between the leads. When the dust or the like gets wet, there is a risk of causing a short circuit between the leads which are the conductive parts and causing a failure. Therefore, various methods are known as measures for preventing the adhesion of dust between the leads.

  For example, as shown in FIG. 3, an insulating tube 56 is inserted into the exposed portion of the lead 54 between the electronic component 50 and the substrate 52, or is exposed between the electronic component 50 and the substrate 52 as shown in FIG. An insulating resin 58 such as silicon rubber is applied to cover the entire lead 54. In addition, as shown in FIG. 5, the entire electronic component 50 is covered with an insulating cap 60, or as shown in FIG. 6, an insulating material 62 formed of an insulating resin is attached to the lead 54 exposed from the substrate 52. However, the leads 54 are insulated from each other.

Further, Patent Document 1 discloses a method in which a connection portion between a high-frequency device surface and each lead is covered with an insulating resin and sealed in an airtight state. Furthermore, Patent Document 2 proposes a method in which a cover member is attached so as to wrap the entire substrate, and a sealing material is filled into a mating portion of the substrate with the base member, so that the substrate is hermetically sealed. In addition, Patent Document 3 discloses a method of protecting the connection terminals and contacts of the substrate from the coating agent when the entire substrate is coated.
Japanese Patent Laid-Open No. 10-41420 Japanese Patent Laid-Open No. 11-243283 JP-A-63-24574

  In the method of inserting the insulating tube 56 into the lead 54 of the electronic component 50 as shown in FIG. 3, if the tube length and the lead length of the portion exposed from the substrate 52 are not aligned with high accuracy, the substrate 52 or the electronic component 50 The main body 50a and the insulating tube 56 did not adhere to each other, and a slight gap t was generated. Then, if foreign matter or dust that has entered invades the gap t and gets wet, there is a possibility that the leads 54 are short-circuited. Further, the method of applying the insulating resin 58 such as silicon rubber so as to cover the entire lead 54 as shown in FIG. 4 is not good in workability since the mounting density of the substrate 52 has recently been increased. there were. In addition, in this case, if the necessity of replacing parts occurs, the labor for peeling off the applied resin is increased, and the number of work steps is increased.

  In addition, in the method of attaching the insulating cap 60 to the entire electronic component 50 shown in FIG. 5, the length of the insulating cap 60 requires high accuracy, and if the accuracy is low, a gap t is generated between the substrate 52 and the substrate. There was a possibility. Further, in the heat generating electronic component 50, the heat sink 64 may be mounted. However, since the fixing hole formed in the electronic component 50 is hidden by the insulating cap 60 and cannot be used, the heat sink 64 is fixed to the heat sink 64. Dedicated parts are required, which is costly and laborious to install. Further, as shown in FIG. 6, in the method of attaching the insulating material 62 molded from the resin to the lead 54 exposed from the substrate 52, a highly accurate insulating material 62 corresponding to the length of the exposed lead 54 is required. If the accuracy is low, there may be a gap t between the substrate 52 or the main body 50a. In addition, there is a restriction in forming the lead 54.

  In addition, these conventional methods are not efficient because of the additional work during assembly work. As shown in FIGS. 3, 5, and 6, when the insulating tube 56 or the insulating material 62 is attached or the insulating cap 60 is attached, the length of the exposed lead 54 or the size of the electronic component 50 is large. There was a need to prepare something in advance.

  On the other hand, in Patent Document 1, the surface of the high-frequency device is hermetically sealed by dropping resin together with the connected lead end, and the terminal when the electronic component is attached to the substrate in a state exposed to the outside air The insulation between them is not disclosed. Further, in Patent Document 2, since the cover member is attached to the base material so as to cover the entire substrate, the cost is high and the size for housing the substrate is required, and the space efficiency is not good. In addition, Patent Document 3 discloses a method for protecting the connection terminals and contacts of the substrate from the coating agent when the entire substrate is coated. However, coating the entire substrate is costly and additional The work efficiency was not good because of the increased work.

  The present invention has been made in view of the above-mentioned problems of the prior art. An electronic component having a high work efficiency and a cost effective, reliably insulated lead for the electronic component, no additional work, and a mounting method thereof. The purpose is to provide.

  The present invention is an electronic component that is attached to a substrate by a lead, and at least the entire lead exposed from the substrate to which the lead is attached is covered with an insulating coating material that can be melted by heat during soldering. An electronic component having an insulating coating formed thereon.

  The insulating coating is made of polyurethane, polyamide, enamel, polyurethane nylon, or enamel nylon.

  The present invention also provides an electronic component mounting method for attaching an electronic component having a lead to a substrate, wherein the entire lead is coated with an insulating coating material that can be melted by heat during soldering to form an insulating film. After that, the lead is inserted into the substrate with the insulating film applied thereto, and the insulating film is removed from the soldered portion of the lead by soldering, so that the electrical connection between the lead and the circuit is achieved. This is a method of mounting an electronic component to be connected.

  The insulating coating is formed by immersing the electronic component in a liquid of the coating material and drying it. In addition, the coating material may be applied to the insulating coating after forming the leads of the electronic component into a predetermined shape.

  According to the electronic component and the mounting method of the present invention, at least the lead portion exposed from the substrate of the electronic component mounted on the circuit board is coated with the insulating film, so that the configuration for ensuring insulation is simple. Yes, the cost for that is reduced. Thereby, it is possible to reliably prevent a short circuit between the leads due to dust or conductive foreign matter. In addition, the coating material is melted by the heat at the time of soldering, and electrical connection is reliably established. Further, the lead surface not to be soldered is reliably insulated, and no additional machining work is required, so that the work efficiency is good.

  Hereinafter, an embodiment of an electronic component and a mounting method thereof according to the present invention will be described with reference to FIGS. As shown in FIG. 1, the electronic component 10 of this embodiment includes a main body 12 formed in a substantially rectangular parallelepiped, a rectangular clasp 14 provided at one end, and a through hole for screwing or the like. 16 is formed. At the opposite symmetrical position, three leads 18 made of a conductor project from the main body 12 and are provided at equal intervals so that they can be inserted into the substrate 20. The entire surface of the lead 18 is completely covered with an insulating coating 22 formed of a coating material made of an insulating resin.

  Next, the procedure for applying the insulating coating 22 to the leads 18 of the electronic component 10 of this embodiment will be described. First, as shown in FIG. 2A, the electronic component 10 held by a transport device (not shown) is immersed in a container filled with a coating material solution 21 for forming the insulating coating 22. At this time, it is preferable to immerse a part of the main body 12 until it touches the solution 21 of the insulating film so that the entire lead 18 is immersed. Next, as shown in FIG. 2B, the electronic component 10 pulled up from the solution 21 is blown by a dryer or the like by a transfer device (not shown) to dry the insulating film 22 coated on the lead 18. As shown in FIG. 2C, the electronic component 10 in which the insulating film 22 is applied to the lead 18 is completed.

  Note that the lead 18 may be formed into an arbitrary shape with a mold or the like before the insulating coating 22 is applied. Accordingly, it is preferable that the insulating coating 22 is not peeled off by performing a bending process or the like after the insulating coating 22 is formed.

  Next, a method for mounting the electronic component 10 of this embodiment will be described. First, as shown in FIG. 2C, the electronic component 10 in which the insulating film 22 is applied to the leads 18 is placed in the lead mounting holes 23 provided in the substrate 20 as shown in FIG. 18 is inserted to an appropriate position. Then, the side periphery of the end of the lead 18 that penetrates to the back side of the substrate 20 and the vicinity of the mounting hole are soldered, and electrical connection and mechanical fixing are performed. At this time, the insulating coating 22 on the surface of the lead 18 is melted by the heat of the melted solder 25, and the solder 25 is connected to the metal surface of the lead 18 to be solidified. Installation on the electrode land is completed.

  According to the electronic component 10 and its mounting method of this embodiment, the coating 18 made of an insulating resin is coated on the lead 18 portion of the electronic component 10 exposed from the substrate 20 to form the insulating film 22. There is no need for installation and no cost. Moreover, the insulating coating 22 is melted and peeled off at the soldered portion by the insulating coating 22 that is melted by the heat at the time of soldering, and does not hinder the electrical connection. Is reliably insulated, requires no additional work, and has high work efficiency. In particular, in an electronic component used in an electronic device that is forcibly cooled by a fan, it is effective in preventing a short circuit due to accumulation of dust or the like between leads.

  In addition, when the insulating coating 22 is applied to the lead 18 of the electronic component 10, the insulating coating 22 may be formed by immersing the entire electronic component 10 in a container of the coating material solution 21. In this case, it is possible to save the trouble of painting only the lead 18 and to improve efficiency. In addition, since the insulating film 22 can be coated on the lead 10 by spraying or dipping in the solution, the shape of the lead 18 can be formed into a desired shape with a mold or the like before the insulating film 22 is applied. It is.

  Note that the electronic component of the present invention and the mounting method thereof are not limited to the above embodiment, and it is sufficient that an insulating film is formed on the surface of the lead. Therefore, the shape and type of the electronic component can be appropriately set. Is. Furthermore, the shape and material of each member can be appropriately changed.

It is a schematic perspective view which shows the electronic component of one Embodiment of this invention. It is process drawing which shows the coating procedure to the lead | read | reed of the electronic component of this embodiment. It is a schematic perspective view which shows the case where a tube is used for the insulation between the leads of the conventional electronic component. It is a schematic perspective view which shows the case where the insulation between the leads of the conventional electronic component is filled with insulating resin. It is a schematic perspective view which shows the case where an insulation cap is used for the insulation between the leads of the conventional electronic component. It is a schematic perspective view which shows the case where a resin molded product is used for the insulation between the leads of the conventional electronic component.

Explanation of symbols

10 Electronic Component 12 Main Body 18 Lead 20 Substrate 22 Insulating Coating 23 Lead Mounting Hole 25 Solder

Claims (5)

  In an electronic component that is attached to a board by a lead, an insulating coating covering at least the entire lead exposed from the board to which the lead is attached is formed by an insulating coating material that can be melted by heat during soldering. Electronic parts characterized by   The electronic component according to claim 1, wherein the insulating coating is made of polyurethane, polyamide, enamel, polyurethane nylon, or enamel nylon.   In an electronic component mounting method for attaching an electronic component having a lead to a substrate, an insulating coating material that can be melted by heat at the time of soldering is used to coat the entire lead to form an insulating film. The lead is inserted into the substrate in a state where the insulating film is applied, and the insulating film is removed from the soldered portion of the lead by soldering, so that the electrical connection between the lead and the circuit is achieved. A method for mounting electronic components.   4. The method of mounting an electronic component according to claim 3, wherein the insulating coating is formed by immersing the electronic component in a liquid of the coating material and drying it. 5. The electronic component mounting method according to claim 3, wherein the insulating coating is formed by applying the coating material after forming the leads of the electronic component into a predetermined shape.

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