JP2014194867A - Lead pin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lead pin which can be formed with a simple structure without requiring any special processing on the printed wiring board side, and can reduce occurrence of a blowhole by enhancing the solder wicking properties.SOLUTION: A center rib 102 is provided around the body 101 of a lead pin 100 in the longitudinal direction, and a notch 1021 is provided at a part of the center rib 102. The lead pin 100 is configured so that a ventilation passage is formed on the front and back of a printed wiring board 200, by interconnecting a through hole 201 of the printed wiring board 200 and the notch 1021.

Description

The present invention relates to a lead pin electrically connected to a conductor portion formed on a printed wiring board. In particular, the present invention relates to a lead pin that improves solderability when the lead pin is mounted on a printed wiring board.

When mounting components or the like on a printed wiring board, mounting by soldering is common. In particular, in the mass production stage, it is required to improve the efficiency of soldering and mounting of components, etc., so the components are temporarily mounted on a printed wiring board, and the printed wiring board is dipped in a solder bath to solder the components. The mounting work is a series of work steps, and the efficiency of soldering work for mounting components and the like on the printed wiring board is improved.

However, when the printed wiring board is dipped in the solder tank and the components are soldered and mounted, there is a concern regarding solderability that the component and the conductor portion of the printed wiring board may not be sufficiently soldered. . More specifically, when the component is a lead component, first, the lead portion of the component is inserted into a through-hole formed in advance on the printed wiring board and is temporarily attached, and then dipped into the solder bath. In addition, there is a concern that a sufficient electrical connection may not be obtained between the lead portion and the conductor portion of the printed wiring board due to poor soldering.

This concern arises because a specific sealed space is created between the printed wiring board and the component main body. That is, in the close contact surface between the printed wiring board and the component main body (for example, an electrolytic capacitor), a space portion surrounded by the thickness of the exterior sleeve of the component main body and the lead-out end surface of the lead portion of the component main body is formed. In the temporarily mounted state before soldering, the space portion communicates with the outside (solder surface side) through a gap between the through hole formed in the substrate through which the lead portion is inserted and the lead portion. When the printed circuit board is dipped in the solder bath, the gap between the through holes is closed by the solder, and the space portion becomes a sealed space.

At this time, due to the heating during soldering, the air in the sealed space may thermally expand and blow out from the through hole to the solder surface side and blow off the solder before solidification. As a result, the lead portion and the conductor portion of the substrate may not be sufficiently soldered. Thus, when a printed wiring board is dipped in a solder tank and a component is soldered and mounted, the solder does not turn well to the lead portion of the component, and the conductive portion between the lead portion of the component and the conductive portion of the printed wiring board is not conductive. Concerns have arisen that there is a possibility that sufficient sex cannot be secured.

In order to solve such a concern, the following solutions have been disclosed conventionally. Broadly speaking, there are two types: one having a specific solution structure on the printed wiring board side and one having a specific solution structure on the electronic component side.

First, as a thing provided with a specific solution structure in a printed wiring board, there exists a thing shown in patent document 1 and patent document 2. FIG.

In Patent Document 1, a rectangular step portion is previously formed by screen printing around a through hole formed in a substrate so that the above-described sealed space does not occur. When the electronic component main body is temporarily mounted on the printed wiring board by the stepped portion, the electronic component main body is slightly lifted from the printed wiring board, and a gap is formed between the printed wiring board and the electronic component main body. The Therefore, even if the air in the space portion is thermally expanded during soldering, the thermally expanded air can escape to the outside through the gap, so that the solder also turns well to the soldered portion of the lead portion, and the conductivity is increased. Is sufficiently secured.

In Patent Document 2, a vent hole communicating with the space portion and the outside is formed in the vicinity of the through hole in the substrate so that the above-described sealed space does not occur. Therefore, even if the air in the space portion is thermally expanded, the thermally expanded air can escape to the outside through the vent hole, so that the solder can be well turned to the soldered portion of the lead portion, and sufficient conductivity is ensured. It is what is done.

Next, as a device having a specific solution structure on the electronic component side, for example, a protrusion is provided on the printed wiring board surface side of the electronic component main body so that the above-described sealed space does not occur. Some electronic component bodies are slightly lifted from the printed circuit board so that the electronic component body is not in close contact with the printed circuit board.

Further, Patent Document 3 discloses an example of a press-fit pin formed so as not to generate the above-described sealed space as a component to be mounted on a printed wiring board. Normally, a press-fit pin is a type in which a pin formed slightly larger than the diameter of the through hole is driven, and after installation, the through hole is closed with a pin head to maintain airtightness. A convex flat plate is formed below the pin head, and a convex flat portion having the same thickness as the head thickness is provided on the inner side of the pin head having a diameter of about twice the pin diameter, and air is passed between the two openings of the through hole. Is intended to be obtained. For this reason, the above-described sealed space does not occur, and solderability can be improved during soldering.

JP-A-6-169142 (FIG. 1) Japanese Utility Model Publication No. 63-102273 (FIG. 1) JP-A-1-120780 (FIG. 1)

In the case of providing a specific solution structure on the printed wiring board side described above, for example, when changing the shape of a component at the time of design change, such as when changing an electronic component to be mounted on the printed wiring board, The case where the said step part and the said air vent which were formed in the board | substrate do not respond | correspond to the component shape after a change is assumed. That is, when the design is changed, it is necessary to change not only the electronic component but also the pattern of the printed wiring board, and there is a possibility that costs and labor for changing the board may occur.

In a press-fit pin disclosed as having a specific solution structure on the electronic component side, it is necessary to process and form a convex flat plate having the same thickness as the head thickness inside the pin head, which may complicate pin processing. There is. In addition, since the pin head has a structure that covers the through hole, once the solder turns inside the pin head, the pin head becomes a heat sink and the solder tends to harden, blocking the ventilation path, and provided below the through hole and the pin head. There is a possibility that the gas in the space with the convex flat part is contracted as it is and blow holes are generated. That is, although the press-fit pin is raised from the substrate to the convex flat part, the top of the through hole is shaped to be covered with the pin head, so that it is assumed that a blow hole may occur.

Therefore, the present invention has been made in view of the above problems, and does not require special processing on the printed wiring board side, and the lead pins themselves can be formed with a simple structure, improving the solder rising property when soldering. An object of the present invention is to provide a lead pin that can reduce the occurrence of blow holes.

The lead pin according to the present invention is configured to solve the above-described problem, and is a lead pin provided with a center collar, and is provided with a notch portion that is notched in the longitudinal direction of the lead pin. Features.

According to such a configuration, by providing a notch portion that is notched in the longitudinal direction of the lead pin in the center, the space formed by the center and the through hole is always in the longitudinal direction, that is, the direction in which the through hole is formed. The ventilation path can be maintained with the outside, and the center of the lead pin covers the through hole of the printed wiring board and does not seal, so the ventilation path is not blocked even after the solder turns to the lead pin. Generation can be reduced.

In addition, a configuration in which the notch is provided point-symmetrically with respect to the axial center of the lead pin can be employed.

According to such a configuration, the notch portion in the middle rib is formed point-symmetrically with respect to the center axis of the lead pin, so that a plurality of the ventilation paths can be maintained and the lead pin is temporarily attached to the through hole of the printed wiring board. In this case, the inclination of the lead pin can be suppressed, and the lead pin can be mounted vertically with respect to the printed wiring board.

In addition, the notch may be configured to be formed from the outer periphery of the intermediate collar to the outer periphery of the lead pin.

According to this configuration, it is possible to reliably ensure a ventilation path for the through hole without increasing the resistance value of the lead pin.

Moreover, the said center rib can employ | adopt the structure formed by inclining in the longitudinal direction of a lead pin.

According to this configuration, the space formed by inclining the volume of the space formed by the through hole and the intermediate hole in the printed wiring board while maintaining the ventilation path with the outside in the direction in which the through hole is formed. Thus, by expanding the space portion in a substantially triangular pyramid shape, the solder area of the component can be increased, and the solder rising property with respect to the lead pin can be further improved.

Further, the notch can adopt a configuration that communicates with the through hole when the lead pin is attached to the through hole of the substrate.

According to such a configuration, it is possible to always maintain the ventilation path with the outside in the direction in which the through hole is formed, so that the gas detachability when the solder rises is improved and the printed circuit board moves when the solder tank moves. Since the rising path can be formed with respect to the solder flow, the solder rising property with respect to the lead pin can be further improved.

As described above, according to the present invention, no special processing is required on the printed wiring board side, and the lead pins themselves can be formed with a simple structure, and the solder rising property is improved during soldering, thereby generating blow holes. A lead pin that can be reduced can be provided.

The perspective view of the lead pin which shows 1st Embodiment is shown. The schematic diagram of the mounting state to the through hole of the printed wiring board in 1st Embodiment is shown. The perspective view of the lead pin which shows 2nd Embodiment is shown. The perspective view of the lead pin which shows 3rd Embodiment is shown. The perspective view of the lead pin which shows 4th Embodiment is shown. The perspective view of the lead pin which shows 5th Embodiment is shown. The perspective view of the lead pin which shows 6th Embodiment is shown. The perspective view of the lead pin which shows 7th Embodiment. The schematic diagram of the mounting state to the through hole of the printed wiring board in 7th Embodiment is shown. A means for improving solderability in a conventional example will be described. A means for improving solderability in a conventional example will be described. A means for improving solderability in a conventional example will be described.

Hereinafter, the present invention will be described with reference to embodiments.
(Embodiment 1)
First, the external configuration of the lead pin according to the present embodiment will be described with reference to FIG. The lead pin 100 according to the present embodiment includes an elongated body portion 101 made of, for example, brass having conductivity, and a middle flange portion 102 formed of the same material around the body portion 101. In the longitudinal direction of the body portion 101, an insertion portion 103 that is inserted into a through hole formed in the printed wiring board is provided on one end side of the middle flange portion 102.

When the longitudinal direction of the body part 101 is a rotation axis, the middle collar part 102 is provided with a notch part 1021 that is notched in the longitudinal direction by a predetermined angle with respect to the radial direction of the middle collar part 102. In the present embodiment, the cutout portion 1021 is configured with a predetermined angle of 45 degrees.

FIG. 2 shows a schematic diagram in the longitudinal direction when the lead pin 100 is mounted in the through hole 201 of the printed wiring board 200.

The notch portion 1021 forms a communication portion 300 with the through hole 201 in the longitudinal direction when the lead pin 100 is attached to the through hole 201 of the printed wiring board 200. By forming the communication portion 300 in the longitudinal direction, the space portion formed by the center flange portion 102 and the through hole can always maintain a ventilation path with the outside, and the center flange portion 102 of the lead pin 100 is printed. Since the through hole of the wiring board is not covered and hermetically sealed, after the solder turns to the lead pin 100, the ventilation path is not blocked and the solder rising property can be secured well, and the occurrence of blow holes can be reduced. .

Further, since the notch 1021 is notched in the longitudinal direction by a predetermined angle with respect to the center of the rotation axis, the position of the notch 1021 is special when inserting the insertion part 103 of the lead pin 100 into the through hole 201. Even if it does not define, the ventilation path of the said space part and the exterior can be maintained, keeping the magnitude | size of the said communication part 300 constant.

(Embodiment 2)
Next, the external configuration of the lead pin according to the present embodiment will be described with reference to FIG. Since the basic configuration of the lead pin 100 according to this embodiment is the same as that of the first embodiment except for the middle collar, the same components as those of the first embodiment are denoted by the same reference numerals, and the middle collar 112 Will be described.

The center pin 112 of the lead pin 100 in the present embodiment is configured by providing notches 1121 at two points symmetrically with respect to the rotation axis center when the longitudinal direction of the body portion 101 is the rotation axis center. doing. The cutout portion 1121 is formed by cutting out the outer peripheral portion of the middle collar portion 112 and forming an arc shape. Since the two notches 1121 are provided, a plurality of the ventilation paths can be maintained and the points are symmetrically provided. Therefore, when the lead pins are temporarily attached to the through holes of the printed wiring board, the lead pins Inclination can be suppressed, and lead pins can be mounted vertically to the printed circuit board.

Note that the notch depth in the notch part 1121 from the outer peripheral side of the middle collar part 112 toward the body part is preferably provided to the extent that the communication part 300 with the through hole 201 is obtained. As a result, even when a lead pin whose body portion 101 is thin with respect to the through hole 201 is used, the lead pin can be mounted vertically on the printed wiring board while ensuring a ventilation path. Further, the shape of the notch 1121 may be formed in a rectangular shape other than the arc shape to form a ventilation path.

(Embodiment 3)
Next, the external configuration of the lead pin according to the present embodiment will be described with reference to FIG. Since the basic configuration of the lead pin 100 according to the present embodiment is the same as that of the second embodiment except for the middle collar, the same components as those of the second embodiment are denoted by the same reference numerals, and the middle collar 122 Will be described.

In the lead pin 100 according to the present embodiment, the center flange 122 is provided with two notches 1221 that are notched from the outer periphery side of the center flange portion 122 to the outer periphery of the lead pin body portion 101. The notch portion 1221 is obtained by providing the notch portion 1021 according to the first embodiment at two locations with point symmetry with respect to the rotation axis center. Further, since the shaft thickness of the lead pin is not changed, a ventilation path can be secured without increasing the resistance value of the lead pin.

Even when the outer shape of the body portion 101 of the lead pin is substantially equal to the inner diameter of the through hole 201, the notch depth of the notch portion 1221 is from the outer peripheral side of the middle flange portion 1221 to the lead pin body portion 101. Since it is provided so as to reach the outer periphery, it is possible to ensure the ventilation path.

(Embodiment 4)
Next, the external configuration of the lead pin according to the present embodiment will be described with reference to FIG. Since the basic configuration of the lead pin 100 according to the present embodiment is the same as that of the third embodiment except for the middle collar, the same components as those of the third embodiment are denoted by the same reference numerals, and the middle collar 132 is provided. Will be described.

In the present embodiment, the middle flange portion 132 of the lead pin 100 is configured to be inclined in the longitudinal direction of the lead pin 100. More specifically, for example, when the state of the middle collar portion 122 of the third embodiment is viewed as a state in which the umbrella is opened, the middle collar portion 132 is formed so as to have a substantially triangular pyramid shape like a state in which the umbrella is half closed. ing. The notch 1321 has a mode in which a part of the intermediate collar 132 having a substantially triangular pyramid shape is notched in the longitudinal direction, and a communicating portion is formed in a three-dimensional manner in the longitudinal direction from the surface of the printed wiring board 200. .

In the present embodiment, when the lead pin 100 is temporarily mounted in the through hole 201, the volume of the space formed by the through hole 201 and the intermediate collar is larger in the fourth embodiment than in the third embodiment. Become. That is, the surface area of the component facing the solder is increased and the conductivity is improved.

In addition, after the solder turns to the insertion portion 103 of the lead pin 100, the solder is likely to rise on the inner wall surface of the substantially triangular pyramid-shaped intermediate collar portion 132 due to a capillary phenomenon, and the notch is formed three-dimensionally in the longitudinal direction. In combination with the portion 1321, generation of blow holes can be effectively suppressed.

(Embodiment 5)
Next, the external configuration of the lead pin according to the present embodiment will be described with reference to FIG. In the lead pin 100 according to the present embodiment, the notch portion 1221 formed in the middle collar portion 122 of the lead pin 100 in the third embodiment is also formed from the outer peripheral side of the middle collar portion 122 to the inside of the body portion 101. It is characterized by.

Here, a notch portion on the middle collar portion 142 is referred to as 1421a, and a notch portion formed inside the body portion 111 is referred to as 1421b. In the present embodiment, the notch portion 1421b formed over the inside of the body portion 101 can increase the surface area of the entire notch portion, constitute a ventilation path in the direction in which the through hole is formed, and when the solder rises In addition to improving the gas release property, a rising path can be formed with respect to the solder flow when the printed wiring board moves through the solder tank.

In addition, even when the outer shape of the body portion 111 of the lead pin is configured to be equal to or slightly larger than the inner diameter of the through hole 201 and fits, the notch portion 1421b formed in the body portion 111 allows the inside and outside of the through hole 201 to be fitted. A ventilation path can be secured.

The notch portion 1421b may be formed over the entire length of the lead pin 100 from one end portion to the other end portion in the longitudinal direction of the body portion 111, or a portion in the longitudinal direction of the body portion 111, that is, the through hole 201. You may form a notch in the thickness of a printed wiring board in the vicinity of the middle collar part 142 so that a ventilation path can be ensured.

(Embodiment 6)
Next, the external configuration of the lead pin according to the present embodiment will be described with reference to FIG. In the lead pin 400 according to the present embodiment, the outer periphery of the lead pin 100 in the first to fifth embodiments is formed in a square pin shape instead of a round pin shape.

The center flange portion 402 formed around the body portion 401 of the lead pin 400 is formed in a rectangular shape in accordance with the outer periphery of the square pin shape. The notch 4021 is configured by notching one side and the opposite side of the body 401 in the longitudinal direction of the lead pin 400.

FIG. 9 shows a schematic diagram in the longitudinal direction when the lead pin 400 is mounted in the through hole 201 of the printed wiring board 200.

The notch 4021 forms the communication part 301 with the through hole 201 in the longitudinal direction when the lead pin 400 is attached to the through hole 201 of the printed wiring board 200. The shape of the communication portion 301 includes a contact portion between a corner portion on one side of the body portion 401 of the lead pin 400 provided with the notch portion 4021 and a wall surface inside the through hole 201, a concave wall surface inside the through hole 201, It becomes a substantially bowl-shaped shape connecting the position side surface side. Compared with the communication part 300 shown in FIG. 2, the volume of the communication part can be made wider, so that the solderability can be improved and the occurrence of blow holes can be suppressed.

By configuring the diagonal length of the peripheral corners of the body portion 401 of the lead pin 400 to be approximately equal to or slightly larger than the inner diameter of the through hole 201, the lead pin 400 can be fitted to the through hole 201. The lead pin 400 can be positioned even in the temporarily mounted state.

(Embodiment 7)
Next, the external configuration of the lead pin according to the present embodiment will be described with reference to FIG. Since the basic configuration of the lead pin 100 according to the present embodiment is the same as that of the sixth embodiment except for the middle collar portion, the same components as those of the sixth embodiment are denoted by the same reference numerals, and the middle collar The unit 412 will be described.

The center pinion 412 of the lead pin 100 in the present embodiment further enlarges the notch portion 4021 of the center pinion portion 402 so that the center rib portion 402 on the side surface of the body portion 401 where the notch portion 4021 is formed. All are cut out. In other words, the middle flange portion 412 is formed by the width of the trunk portion 401 on one side surface side and the opposite side surface side of the trunk portion 401.

In the case of this embodiment, the shape of the lead pin 400 can be a substantially two-dimensional shape. Therefore, compared to the case of the sixth embodiment, the shape of the lead pin 400 can be further simplified, and the gas release property and the solder rising property at the time of solder rising can be achieved by the communication portion having an increased volume. It can be improved further.

In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of this invention.

For example, the predetermined angle of the notch portion 1021 of the middle collar portion 102 may be 30 degrees or 90 degrees in addition to 45 degrees. Even if it is enlarged to approximately 180 degrees, the object of the present application is achieved as long as it communicates with the through hole of the printed wiring board.

Further, the number of the notch portions 1121 of the middle collar portions 112, 122, 132, 142 may be provided at four places in addition to two places. In addition, the object of the present application can be achieved even in three places.

Moreover, you may comprise the thickness of the longitudinal direction in the insertion part of a lead pin in a taper shape toward the front end side of an insertion part. As a result, in addition to improving the solderability, it is possible to improve the insertability of the lead pins into the through hole 201 of the printed wiring board 200, and to improve the efficiency of soldering and mounting work in the mass production stage.

100 lead pin 101 trunk portion 102 middle collar portion 1021 notch portion 103 insertion portion 112 middle collar portion 1121 notch portion 122 middle collar portion 1221 notch portion 132 middle collar portion 1321 notch portion 142 middle collar portion 1421 notch portion 400 lead pin 401 Body part 402 Middle collar part 4021 Notch part 412 Middle collar part 4121 Notch part 200 Printed wiring board 201 Through hole 300 Communication part 301 Communication part

Claims (5)

A lead pin with a medium collar,
A lead pin comprising a notch portion cut out in a longitudinal direction of the lead pin in the center.
The notch is
The lead pin according to claim 1, wherein the lead pin is provided point-symmetrically with respect to an axial center of the lead pin.
The notch is
The lead pin according to claim 1, wherein the lead pin is formed from an outer peripheral portion of the intermediate collar to an outer peripheral portion of the lead pin.
The lieutenant is
The lead pin according to any one of claims 1 to 3, wherein the lead pin is formed to be inclined in a longitudinal direction of the lead pin.
The lead pin according to any one of claims 1 to 4, wherein the notch portion communicates with the through hole when the lead pin is attached to the through hole of the substrate.

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