JP2015122406A - Circuit device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit device capable of preventing solder dripping while minimizing a contact area between a terminal and a substrate.SOLUTION: In a circuit device 1 formed by inserting a terminal 10 into a hole 4 formed on a substrate 2 and bonding the terminal 10 by a solder, the terminal 10 has an insertion part 11 which is located inside the hole 4 and a projection 12 located outside the hole 4 and projects along the substrate. In a state where the terminal 10 is inserted in the hole 4, the projection 12 is located on a surface side of the substrate 2 toward which an element 5 is moved when the element 5 is to be attached and located at a position away from the surface. In addition, on each of both surfaces of the substrate 2, a land 3 is exposed on an edge of the hole 4 and a solder fillet F is formed between the land 3 and the terminal 10.

Description

  The present invention relates to a circuit device, and more particularly, a substrate having a hole portion and a conductive portion formed in a flange portion of the hole portion and having conductivity, and bonded to the substrate in a state of being inserted into the hole portion by solder. And a terminal device.

  A circuit device comprising a substrate having a hole and a conductive portion formed in a flange portion of the hole and having conductivity and a terminal that is inserted into the hole and soldered to the substrate is already provided. An apparatus described in Patent Documents 1 and 2 is given as an example. In the circuit board structure described in Patent Document 1, in a configuration in which lead terminals are inserted into holes in the board and welded with solder, ring-shaped protrusions are provided on the peripheral portions of the terminals on the board. As a result, it becomes possible to confine the solder that has been scooped up in the peripheral portion of the terminal, and as a result, it is possible to avoid a short circuit caused by the solder that has been scooped up coming into contact with another adjacent electronic component. Is possible.

  Regarding the electronic element described in Patent Document 2, when the terminal is inserted through the hole of the substrate, the flange portion provided at one end of the terminal is connected to the conductive portion in the substrate (the pad portion of Patent Document 2). The terminal is positioned and the flange portion and the conductive portion are welded with solder. Thereby, in the electronic device described in Patent Document 2, it is possible to ensure a wide contact area between the terminal and the substrate, and as a result, the conductive portion and the terminal are securely bonded to increase the bonding strength. It becomes possible.

JP-A-8-116152 JP-A-10-79574

Incidentally, when the terminals are welded to the substrate with solder, it is desirable that the solder be soldered so as to form a fillet F between the terminal 101 and the conductive portion 103 of the substrate 102 as shown in FIG. . FIG. 4 is a diagram showing an ideal solder joint state.
However, improper operations such as insufficient substrate heat during soldering, excessive heating of the tip of the soldering iron, or excessively long soldering time are performed. Then, there is a possibility that a sufficient fillet F is not formed. Further, if the soldering is continued in such a situation, the solder hangs down along the terminals, resulting in a solder pool as shown in FIG. FIG. 5 is an explanatory diagram of a solder pool.

  On the other hand, with the techniques of Patent Documents 1 and 2 described above, it is difficult to suppress insufficient fillet formation due to the solder dripping described above. In the technique described in Patent Document 2, when a metal terminal flange and a resin substrate are joined together and then welded with solder, due to a difference in thermal contraction rate (expansion rate) between the two materials. As a result, stress is generated in the joined solder. As a result, a crack is generated in the bonding solder, and the crack may cause a conduction failure.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to reduce the contact area between the terminal and the substrate as much as possible as a circuit device configured by joining the terminal to the substrate with solder. However, an object of the present invention is to provide an apparatus capable of suppressing the dripping of solder.

  According to the circuit device of the present invention, the problem is that a substrate having a hole portion and a conductive portion formed at a flange portion of the hole portion and having conductivity, and soldered to the substrate while being inserted through the hole portion. A circuit device configured by attaching an element to the substrate by bringing the element close to the substrate from the front surface side of both the front surface and the back surface of the substrate. The terminal includes an insertion portion located in the hole in the state, and a protrusion that protrudes along the substrate and is located outside the hole in the state. Is located on the same side as the front surface when viewed from the back surface and at a position away from the front surface, the conductive portion is exposed on each of both surfaces, and the solder fillet is between the conductive portion and the terminal. It is solved by being formed.

  In the circuit device described above, the protrusion provided on the terminal functions as a solder flow stop. As a result, the occurrence of solder accumulation is suppressed, and a solder fillet is favorably formed between the terminal and the conductive portion of the substrate. In addition, since the protruding portion is located away from the substrate in a state where the terminal is inserted through the hole portion, the terminal is appropriately bonded to the substrate with solder while suppressing an increase in the contact area between the terminal and the substrate. It becomes possible to make it.

Further, in the above circuit device, the terminal has an adjacent portion that is adjacent to the protruding portion and is continuous with the insertion portion in the extending direction of the terminal, and the protruding portion is formed on a side surface of the adjacent portion. It is preferable that the projection protrudes from at least one of them. Further, it is more preferable that the protruding portion protrudes from two locations on the side surface so as to protrude in opposite directions.
If it is the above structure, the effect by providing a protrusion part, ie, the effect which stops dripping of solder and suppresses generation | occurrence | production of a solder pool will be exhibited more effectively.

Further, in the above circuit device, the extending direction of the terminal is along the normal direction of each of the both surfaces, and the insertion portion and the protruding portion are in the extending direction and the protruding direction of the protruding portion. More preferably, the thicknesses in the direction perpendicular to both are the same.
If it is the above structure, the effect by providing a protrusion part, ie, the effect which stops dripping of solder and suppresses generation | occurrence | production of a solder pool will be exhibited more effectively.

In the above circuit device, it is even more preferable that the insertion portion and the protruding portion are integrally formed.
If it is the above structure, it will become easy to provide a protrusion part in a terminal.

In the above circuit, it is more preferable that a clearance is provided between the insertion portion and the conductive portion in the hole, and a part of the solder is submerged in the clearance. .
With the above configuration, if a gap is formed between the terminal and the conductive portion in a state where the terminal is inserted through the hole formed in the substrate, the solder will sink into the gap, and the gap It becomes easy to hang down through. In such a configuration, if the projecting portion is provided on the terminal, the function of the projecting portion becomes more meaningful. That is, in the above configuration, the circuit device of the present invention provides a more beneficial effect.

According to the circuit device of the present invention, the protrusion provided on the terminal functions as a solder flow stopper. As a result, the generation of solder pools is suppressed, so that a solder fillet is well formed between the terminal and the conductive portion of the substrate, so that the terminal is appropriately bonded to the substrate.
On the other hand, as disclosed in Patent Document 2, when soldering is performed in a state in which a flange portion is provided on the terminal and the flange portion is in contact with the substrate after joining the terminal and the substrate with solder, Due to the difference in thermal shrinkage rate (expansion rate) between the material and the material of the substrate, cracks occur in the solder joint. On the other hand, according to the circuit device of the present invention, since the protruding portion provided on the terminal to be appropriately bonded to the substrate is separated from the substrate, the contact area between the terminal and the substrate increases. This makes it possible to suppress the occurrence of the cracks.
Due to the above effects, the circuit device of the present invention can appropriately bond the terminal to the substrate without particularly requiring work skills. For this reason, the quality of a device equipped with the circuit device of the present invention is also improved.

It is a conceptual diagram which shows the structure of the circuit apparatus which concerns on one Embodiment of this invention. It is a perspective view which shows the front-end | tip part of the terminal which concerns on one Embodiment of this invention. 1 is a schematic cross-sectional view showing a periphery of a terminal in a circuit device according to an embodiment of the present invention. It is a figure which shows an ideal solder joint state. It is explanatory drawing of a solder pool.

<< About One Embodiment of the Present Invention >>
Hereinafter, an embodiment (this embodiment) of the present invention will be described with reference to the drawings. Note that this embodiment is merely an example for facilitating understanding of the present invention, and does not limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof. In particular, the shape, material, dimensions, and the like of each component of the circuit device are not limited to the contents described in this embodiment, and can be arbitrarily designed without departing from the spirit of the present invention.

  As shown in FIG. 1, the circuit device 1 according to the present embodiment is configured by attaching an element 5 such as a connector close to the substrate 2 from the surface side of the substrate 2. FIG. 1 is a conceptual diagram showing a configuration of a circuit device 1 according to the present embodiment. More specifically, the substrate 2 includes a land 3 as a conductive portion and a hole 4 formed inside the land 3. On the other hand, a metal terminal 10 is inserted through the hole 4. And the insertion part 11 and the land 3 which are the part located in the hole part 4 among the terminals 10 are joined with the solder.

  Here, the terminal 10 includes a terminal portion (lead) that the electronic component (element 5) mounted on the circuit device 1 has to be conductive, a power supply terminal for supplying power to the electronic component, a ground terminal, and The output terminal etc. for amplifying and outputting the change of the resistance value in the resistor used as an electronic component are included.

  In the present embodiment, the terminal 10 has a rectangular cross section as shown in FIG. 2 and has a slight thickness. FIG. 2 is a perspective view showing the tip of the terminal 10 according to the present embodiment. Further, the terminal 10 is inserted into the hole 4 from the front surface side of the substrate 2, and is joined to the substrate 2 with the tip portion slightly protruding from the back surface of the substrate 2 as shown in FIG. 1. Further, in the present embodiment, the terminal 10 is inserted through the hole 4 in a state in which the extending direction is along the normal direction of both the front surface and the back surface of the substrate 2.

  The substrate 2 includes a main body made of glass epoxy resin, a hole (through hole) 4 formed in the main body, and a land 3 formed in a flange portion of the hole 4 and having conductivity. The land 3 is made of a copper foil and is exposed on the front surface and the back surface of the substrate 2. More specifically, the land 3 is developed on the surface of the substrate 2 from the edge of the hole 4 toward the outside (front side part) and on the back side of the substrate 2 is expanded from the edge of the hole 4 toward the outside. And a portion (connecting portion) that is located in the hole 4 and connects the front side portion and the back side portion.

  The hole 4 is formed to be slightly larger than the outer shape of the terminal 10. Accordingly, a gap is formed between the inner wall of the hole 4 (strictly speaking, the connecting portion of the land 3) and the terminal 10 in a state where the terminal 10 is inserted into the hole 4.

  By the way, the terminal 10 is joined to the board | substrate 2 in the state penetrated by the hole 4 as mentioned above. On the other hand, as shown in FIG. 2, the terminal 10 is inserted in the hole 4 in a state where the terminal 10 is inserted in the hole 4 (hereinafter referred to as “inserted state”), and the insertion direction of the terminal 10. And an adjacent portion 13 continuous with the insertion portion 11. In the inserted state, the adjacent portion 13 is outside the hole portion 4 as shown in FIG. 3, more precisely, on the same side as the front surface when viewed from the back surface of the substrate 2 and at a position away from the front surface. FIG. 3 is a schematic cross-sectional view showing the periphery of the terminal 10 in the circuit device 1 according to the present embodiment.

  And if the structure which is the characteristics of this embodiment is described, a pair of protrusion part 12 will protrude from the side surface of the adjacent part 13. The pair of projecting portions 12 are provided at positions adjacent to the adjacent portions 13 in the terminal 10 (in other words, the adjacent portions 13 are adjacent to the respective projecting portions 12). In addition, the pair of projecting portions 12 project in a convex shape in opposite directions from two locations separated from each other by about 180 degrees on the side surface of the adjacent portion 13. In the present embodiment, each protruding portion 12 is formed in a substantially rectangular parallelepiped shape, and the protruding direction is substantially orthogonal to the extending direction of the terminal 10.

  Moreover, in this embodiment, the insertion part 11, the adjacent part 13, and the protrusion part 12 are formed so that each thickness may become the same. However, it is not limited to this, It is good also as each thickness of the insertion part 11, the adjacent part 13, and the protrusion part 12 differing. Here, the thickness is a thickness in a direction orthogonal to both the extending direction of the terminal 10 and the protruding direction of the protruding portion 12.

In the present embodiment, the insertion portion 11, the adjacent portion 13, and the protruding portion 12 are integrally formed. Specifically, when the portion serving as the base material of the terminal 10 is cut out from the metal plate, the protruding portion 12 is provided. Press cutting or the like is performed so that corresponding portions are simultaneously formed. Thereby, the terminal 10 provided with the protrusion part 12 can be easily formed.
However, the protruding portion 12 is not limited to being integrally formed with the insertion portion 11 and the adjacent portion 13. For example, a component corresponding to the protruding portion 12 may be separately prepared and attached to a predetermined position of the terminal 10. .

  And the protrusion part 12 is located outside the hole part 4 in the insertion state, and more precisely, is located on the same side as the surface when viewed from the back surface of the substrate 2 and at a position away from the surface. Further, in the inserted state, the protruding portion 12 protrudes so that the protruding direction is along the substrate 2, that is, parallel to each of the front surface and the back surface of the substrate 2.

  In the above state, the insertion portion 11 and the land 3 are joined by solder on the front surface side and the back surface side of the substrate 2, respectively. A part of this solder joins in a gap formed between the insertion portion 11 and the land 3 in the hole 4 and, as shown in FIG. A skirt-like fillet F is formed between the two. As a result, the terminal 10 is appropriately bonded to the substrate 2 with solder.

  The effectiveness of the present embodiment will be described again. As described in the section of the problem to be solved by the invention, after inserting the terminal 10 into the hole 4, the insertion portion 11 in the terminal 10 and the land 3 are soldered. If soldering is attempted, solder may fall down along the terminal 10. Such solder dripping causes a solder pool illustrated in FIG. 5, and when the solder pool occurs, an appropriate fillet F is not formed between the land 3 and the terminal 10.

  In addition, if a gap is formed between the insertion portion 11 and the land 3 in the hole portion 4, the above-described problem occurs more remarkably because the solder tends to sag by passing through the gap. It will end up.

  On the other hand, in the present embodiment, the protruding portion 12 is provided on the terminal 10, and the protruding portion 12 functions as a solder flow stop. More specifically, even if the solder is about to drip, the solder is regulated by the regulation surface of the protrusion 12 (the surface facing the land 3). In this way, the solder dripping is restricted, so that the solder adhered between the terminal 10 and the land 3 is held at that position. As a result, the occurrence of solder pools is suppressed, and a solder fillet F is favorably formed between the terminal 10 and the land 3. The above effect (that is, the effect of suppressing solder dripping) is particularly effective when a gap is formed between the insertion portion 11 and the land 3 in the hole 4, that is, in a process in which solder dripping is likely to occur. It becomes effective.

  In the present embodiment, since a pair of protrusions 12 are formed and these protrude in opposite directions, for example, compared with the case where only one protrusion 12 is formed, the soldering is more effectively performed. It is possible to suppress dripping. Moreover, in this embodiment, each thickness of the insertion part 11, the adjacent part 13, and each protrusion part 12 in the terminal 10 is the same. Thereby, it is possible to suppress the dripping of the solder more effectively as compared with the configuration in which the thickness is thinner than the portion of the protruding portion 12 type.

  Further, in the present embodiment, the protruding portion 12 protrudes along the substrate 2, in other words, the regulation surface of each protruding portion 12 is substantially parallel to the surface of the substrate 2. Thereby, it is possible to more effectively suppress the dripping of the solder.

  Further, in the present embodiment, the protruding portion 12 is located away from the substrate 2 when the terminal 10 is in a state (inserted state) inserted through the hole 4. This eliminates the need to increase the contact area by abutting both components for the purpose of bonding the terminal 10 to the substrate 2, and the adverse effect of increasing the bonding area (specifically, cracks occur in the bonding solder). Can be suppressed.

DESCRIPTION OF SYMBOLS 1 Circuit apparatus 2 Board | substrate 3 Land (conductive part)
4 Hole 5 Element 10 Terminal 11 Insertion Part 12 Projection Part 13 Adjacent Part 101 Terminal 102 Substrate 103 Conductive Part F Fillet

Claims (6)

A substrate having a hole and a conductive part formed on the flange of the hole and having conductivity;
A terminal that is soldered to the substrate in a state of being inserted into the hole, and of both the front surface and the back surface of the substrate, the device is brought close to the substrate from the front surface side, and the device is A circuit device configured by being attached to a substrate,
The terminal includes an insertion portion that is located in the hole in the state, and a protrusion that is located outside the hole and protrudes along the substrate in the state.
The protrusion is on the same side as the surface as viewed from the back surface, and at a position spaced from the surface,
The circuit device according to claim 1, wherein the conductive portion is exposed on each of the two surfaces, and the solder fillet is formed between the conductive portion and the terminal. The terminal has an adjacent portion adjacent to the protruding portion and continuous with the insertion portion in the extending direction of the terminal,
The circuit device according to claim 1, wherein the protruding portion protrudes in a convex shape from at least one of the side surfaces of the adjacent portion.   The circuit device according to claim 2, wherein the protruding portion protrudes from two locations on the side surface so as to protrude in opposite directions. The extending direction of the terminal is along the normal direction of each of the both surfaces,
The insertion portion and the protrusion are formed so that the thickness in a direction orthogonal to both the extending direction and the protrusion direction of the protrusion is the same. A circuit device according to claim 1.   The circuit device according to claim 1, wherein the insertion portion and the protruding portion are integrally formed. In the hole, a gap is provided between the insertion portion and the conductive portion,
The circuit device according to claim 1, wherein a part of the solder is embedded in the gap.

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