JP2015046479A - Circuit configuration - Google Patents

Abstract

The present invention provides a circuit configuration body in which positioning of a bus bar with respect to a printed circuit board is easy and positional deviation does not occur.
A printed circuit board having a printed circuit board on which a circuit made of a conductive metal material is formed on an insulating substrate and a bus bar laminated on the printed circuit board. A through-hole is formed, and a positioning projection that is press-fitted into the positioning through-hole and positions the bus bar with respect to the printed circuit board is provided at a position corresponding to the positioning through-hole in the bus bar.
[Selection] Figure 2

Description

  The present invention relates to a circuit structure formed by stacking bus bars on a printed circuit board.

  Since the copper foil pattern of the printed circuit board is thin and the current capacity is small, when a relatively large current is controlled to be cut off, the circuit configuration is such that a bus bar made of a copper plate is laminated on the printed circuit board to form a conductive path for the load circuit The body is known for a long time. A plurality of these bus bars are bonded and fixed to the printed circuit board with an adhesive or an adhesive sheet.

JP 2003-164040 A

  By the way, in this type of configuration, the bus bar is solder-connected to a terminal such as an FET that is a switching element mounted on the printed circuit board. Therefore, when the bus bar is fixed to the printed circuit board, accurate positioning is required. is there.

  In addition, when simply bonding with an adhesive or an adhesive sheet, the adhesive or the adhesive sheet is softened by heat during the pasting operation or when the product is used, and a positional deviation occurs between the bus bar and the printed circuit board. There is a fear. Such misregistration also becomes a factor that hinders the increase in the density of the printed circuit board. Therefore, a high-quality material having high adhesive strength and excellent heat resistance must be used as the adhesive material.

  The present invention has been completed based on the above situation, and a circuit structure that can accurately position the bus bar with respect to the printed circuit board and can increase the fixing force of the bus bar to the printed circuit board. It is intended to provide.

  The present invention made to solve the above problems is a circuit structure comprising a printed circuit board in which a circuit made of a conductive metal material is formed on an insulating substrate, and a bus bar laminated on the printed circuit board. A positioning through hole is formed in the printed circuit board, and the printed circuit of the bus bar is pressed into the positioning through hole at a position corresponding to the positioning through hole in the bus bar. It is characterized in that a positioning projection for positioning the substrate is provided.

  According to such a configuration of the present invention, the positioning protrusion provided on the bus bar is press-fitted into the positioning through hole of the printed circuit board so that the bus bar and the printed circuit board can be accurately positioned. . In addition, since the positioning protrusion is press-fitted into the positioning through-hole of the printed circuit board, the adhesive force and heat resistance of the adhesive and the adhesive sheet can be compensated by the fixing force of the press-fitting structure, and the low-grade adhesive material Can be used, or an adhesive material can be dispensed with.

  The positioning protrusion may be a conductive member that is press-fitted into a bus bar through-hole provided in the bus bar and protrudes from the surface of the bus bar. According to such a configuration, since it is possible to position the bus bar with respect to the printed circuit board by using a conductive member that originally conducts the circuit and the bus bar, there is no need to provide a positioning protrusion or hole. Therefore, simplification and miniaturization of the circuit structure can be realized.

  Alternatively, the positioning protrusion may be a bent portion obtained by bending a part of the bus bar. According to such a configuration, the positioning protrusion can be provided easily and inexpensively.

  A plurality of bus bars may be provided, and one or more positioning protrusions may be provided for each bus bar. According to such a configuration, even when a plurality of bus bars are used, each bus bar can be easily positioned with respect to the printed circuit board.

  Moreover, the surface orthogonal to the press-fitting direction and the positioning holes in the positioning protrusions may be triangular or quadrangular. With such a configuration, positional displacement is less likely to occur compared to a circular configuration.

  In addition, the positioning protrusion has a connecting surface in which the protruding end surface is flush with the surface of the insulating substrate in a state where it is press-fitted into the positioning through-hole, and the terminal of the electronic component is electrically connected to the connecting surface. It is good also as a structure connected to.

  According to such a configuration, the soldering operation of the terminals of the electronic component is facilitated, and the connection reliability can be improved.

  Further, the terminals of the electronic components may be connected between different bus bars.

  ADVANTAGE OF THE INVENTION According to this invention, the position accuracy of a bus bar with respect to a printed circuit board can be improved, and also the circuit structure body with high fixation strength of a bus bar can be obtained.

Exploded sectional view of bus bar and inlay of embodiment 1 Exploded sectional view of busbar with inlay and printed circuit board Cross-sectional view of a stacked state of busbar with inlay and printed circuit board Side cross-sectional view of circuit structure Plan view of printed circuit board Top view of bus bar Exploded sectional view of bus bar and inlay of embodiment 2 Exploded sectional view of busbar with inlay and printed circuit board Cross-sectional view of a stacked state of busbar with inlay and printed circuit board Side cross-sectional view of circuit structure Plan view of printed circuit board Top view of bus bar

<Embodiment 1>
Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 6. In the following description, the upper side in FIG. 4 is described as the front side, and the lower side is described as the back side.

(Circuit structure 10)
As shown in FIG. 4, the circuit structure 10 according to the present embodiment includes a printed circuit board 11, an electronic component 20 mounted on the front surface of the printed circuit board 11, and a plurality of layers stacked on the back surface of the printed circuit board 11. Bus bar 30.

(Printed circuit board 11)
The printed circuit board 11 has a substantially rectangular shape as shown in FIG. 5 when viewed from the front and back direction (vertical direction in FIG. 4), and the surface of the insulating substrate is formed of a conductive metal such as copper foil by printed wiring technology. A signal circuit (not shown) made of a material is formed. The printed circuit board 11 is formed with a plurality of positioning through holes 12 (four are illustrated in the present embodiment) that penetrate in the thickness direction (see FIG. 2). Each of the positioning through holes 12 has a rectangular shape.

(Electronic component 20)
As shown in FIG. 4, a plurality of terminals 21 are led out from an electronic component 20 which is a semiconductor switching element such as an FET. These terminals 21 are electrically connected to an inlay 35 and / or a signal circuit, which will be described later, exposed on the surface of the printed circuit board 11 by a known method such as soldering.

(Bus bar 30)
As shown in FIG. 4, on the back surface of the printed circuit board 11, a plurality of bus bars 30 (three illustrated in the present embodiment) formed by pressing a metal plate made of, for example, a copper alloy are stacked on one side. These are bonded to the printed circuit board 11 with an adhesive (not shown).

  In each bus bar 30, a bus bar through hole 31 is formed at a position corresponding to the positioning through hole 12 of the printed circuit board 11 in a state where the bus bar 30 is laminated at a predetermined position of the printed circuit board 11. The bus bar through hole 31 is also rectangular. The inner diameter dimension of the positioning through hole 12 and the inner diameter dimension of the bus bar through hole 31 are set to substantially the same dimension.

  Each bus bar through-hole 31 is provided with an inlay 35 (an example of a conductive member) made of a conductive metal material (see FIG. 2). The inlay 35 is a quadrangular columnar member having an outer diameter slightly smaller than the inner diameter of each bus bar through hole 31, and is fixed to the bus bar 30 by being press-fitted into the bus bar through hole 31.

  As shown in FIG. 2, each inlay 35 is flush with the bus bar 30 on the back surface side (lower side in FIG. 2) of the bus bar 30 and on the front surface side (upper side in FIG. 2) of the bus bar 30. It is fixed so as to protrude upward from the surface of the bus bar 30, and an end surface 36 </ b> A (an example of a protruding end surface) of the protrusion 36 (an example of a positioning protrusion) is laminated on the printed circuit board 11. In this state, it is set to be substantially flush with the surface of the printed circuit board 11 (insulating board) (see FIG. 3). In other words, the inlay 35 protrudes from the surface of the bus bar 30 with a rising dimension equivalent to the thickness of the printed circuit board 11 (insulating board). The substantially flush surface includes the case where the surface of the printed circuit board 11 and the end surface 36A of the protruding portion 36 of the inlay 35 have the same height, and are substantially the same even if they are not the same height. Including cases where it is acceptable.

  The terminal 21 of the electronic component 20 described above is electrically connected to the end surface 36A of the inlay 35 by a known method such as soldering. That is, the end surface 36A of the inlay 35 is a connection surface to which the terminal 21 is connected.

  Also, as shown in FIG. 3, the plurality of bus bars 30 are set in advance so as to be arranged at intervals in the left-right direction in FIG. 3 while being stacked on the printed circuit board 11.

(Manufacturing process)
Then, an example of the manufacturing process of the circuit structure 10 of this embodiment is demonstrated. First, a metal plate material is processed by an arbitrary method such as forging, casting, or pressing to form an integrated bus bar in which a plurality of bus bars 30 having a predetermined shape are connected together by a connecting frame (not shown). Each bus bar 30 is formed with one or two bus bar through holes 31 (see FIG. 6).

  Next, as shown in FIG. 1, the inlay 35 is press-fitted into each bus bar through hole 31. Each inlay 35 press-fitted into each bus bar through-hole 31 is firmly fixed in the bus bar through-hole 31 because its outer diameter is set to be slightly smaller than the inner diameter of each bus bar through-hole 31. At this time, as shown in FIG. 2, the lower end surface 37 of the inlay 35 and the back surface of the bus bar 30 are flush with each other on the back surface side of the bus bar 30, and the protruding portion 36 of the inlay 35 is on the front surface side of the bus bar 30. Is configured to protrude from the surface of the bus bar 30 by a predetermined dimension (a dimension equivalent to the thickness of the printed circuit board 11).

  Next, the bus bar 30 to which the inlay 35 is fixed is laminated on the back surface side of the printed circuit board 11 from the direction indicated by the arrow in FIG. At this time, the positioning through hole 12 of each printed circuit board 11 has a rectangular shape having an inner diameter slightly larger than the outer diameter of the protruding portion 36 of the inlay 35 protruding from the surface of the bus bar 30. It is possible to press fit relatively close to the positioning through hole 12.

  Thereby, the printed circuit board 11 and the bus bar 30 are assembled in a laminated state, and are fixed by press-fitting the inlay 35 into the printed circuit board 11 and the adhesive force of the adhesive (see FIG. 3). Thereafter, the connecting frame that integrates the bus bars 30 is cut, and the bus bars 30 are individually separated. In this state, the end surface 36 </ b> A of the protruding portion 36 of the inlay 35 is flush with the surface of the printed circuit board 11.

  Thereafter, required electronic components are mounted on the surface side of the printed circuit board 11 and the components are mounted by, for example, reflow soldering. The terminals 21 of some of these electronic components are soldered to the exposed end surface 36A of the inlay 35, and the circuit structure 10 is completed.

(Function, effect)
Then, the effect | action and effect of this embodiment are demonstrated. According to the present embodiment, since the protruding portion 36 of the inlay 35 fixed to the bus bar 30 is press-fitted into the positioning through hole 12 of the printed circuit board 11, the bus bar 30 and the printed circuit board 11 are accurately positioned. Is done. Further, since the fixing force due to the press-fitting structure of the inlay 35 to the printed circuit board 11 acts, the adhesive or adhesive sheet for bonding the bus bar 30 to the printed circuit board 11 has low adhesive force or heat resistance. Even if a low-quality one is used, the adhesive force of the bus bar 30 to the printed circuit board 11 is sufficient.

  Further, since the terminal 21 of the electronic component 20 is soldered to the inlay 35 for positioning the printed circuit board 11 and the bus bar 30, the circuit connected to the bus bar 30 can be rationally configured. Simplification and miniaturization can be realized.

  Moreover, since the inlay 35 (protrusion part 36) is provided in each of the some bus bar 30, each bus bar 30 is positioned correctly.

  In addition, since the inlay 35 has a quadrangular prism shape, it is possible to effectively prevent the displacement of the bus bar 30 as compared with a cylindrical configuration.

  The inlay 35 forms a connection surface in which the end surface 36A of the protruding portion 36 is flush with the surface of the insulating substrate (printed circuit board 11) in a state where the inlay 35 is press-fitted into the positioning through hole 12. Since the terminal 21 of the electronic component 20 is electrically connected to the connection surface, the terminal 21 of the electronic component 20 mounted on the printed circuit board 11 can be soldered at once by a reflow soldering method. Productivity is high.

<Embodiment 2>
Next, Embodiment 2 of the present invention will be described with reference to FIGS.
In the following description, only the configuration different from that of the first embodiment will be described. For the same configuration as that of the first embodiment, the reference numeral added to each configuration of the first embodiment is used. And

  In the present embodiment, as shown in FIG. 11, the positioning through hole 52 (hereinafter referred to as the first positioning through hole 52 </ b> A) disposed at the left end in the drawing is smaller in diameter than the other positioning through holes 52. The bent portion 72 of the bus bar 70 described later can be received. As shown in FIGS. 8 and 9, the printed circuit board 51 is provided with openings 53 extending over two adjacent bus bars 30 in addition to the plurality of positioning through holes 52.

  On the other hand, in the first bus bar 70A arranged at the left end in FIG. 7 and FIG. 12, instead of forming the bus bar through hole 71, the bent portion is cut from the left end edge and bent in the vertical direction. 72 is formed. Note that through holes are not formed in portions of the plurality of bus bars 70 corresponding to the openings 53 of the printed circuit board 51 (see FIG. 9).

  The inlay 75 is press-fitted and fixed in each bus bar through-hole 71 of the bus bar 70 of this embodiment as in the first embodiment (see FIG. 7). Then, the bus bars 70 are stacked on the back side of the printed circuit board 51 from the direction indicated by the arrows in FIG. Then, as shown in FIG. 9, the protruding portion 76 of the inlay 75 is press-fitted into the positioning through hole 52 of the printed circuit board 51, and the end surface 76 </ b> A of the protruding portion 76 of the inlay 75 is the printed circuit board 51. It is arranged flush with the surface of the. Further, in the portion where the opening 53 is formed, the upper surface of the bus bar 70 is exposed through the opening 53. Further, for the first bus bar 70 </ b> A disposed at the left end in FIG. 9, the bent portion 72 is press-fitted into the first positioning through hole 52 </ b> A of the printed circuit board 51, and the end surface 72 </ b> A is the surface of the printed circuit board 51. It is arranged flush with.

  Next, the terminal 61 of the electronic component 60 is placed on the end surface 76A of the protrusion 76 of the inlay 75 exposed on the surface of the printed circuit board 51 and the bus bar 70 exposed in the opening 53, and soldering is performed. At this time, as shown in FIG. 10, the pair of terminals 61 of the electronic component 60 arranged on the left side in the drawing is directly on each surface of the adjacent bus bar 70 disposed at a position lower than the surface of the printed circuit board 51. Since they are connected, the overall height of the circuit structure 50 can be reduced as compared with the first embodiment.

  Further, the first bus bar 70A disposed at the left end in FIGS. 10 and 12 is not provided with the bus bar through hole 71 (inlay 75), but the bent portion 72 passes through the printed circuit board 51 for the first positioning. By press-fitting into the hole 52A, the bus bar 70 can be accurately positioned with respect to the printed circuit board 51 as in the first embodiment.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

  (1) The shape of the positioning through holes 12 and 52 and the bus bar through holes 31 and 71 is not limited to a rectangular shape, and may be a polygonal shape such as a circular shape or a triangular shape, and an arbitrary shape as necessary. Can do.

  (2) In the above embodiment, the bus bars 30 and 70 are fixed to the printed circuit boards 11 and 51 by press-fitting the inlays 35 and 75 into the positioning through holes 12 and 52, and an insulating adhesive sheet or adhesive However, the adhesive material may be omitted when the bus bar fixing force can be obtained by the inlay press-fitting structure.

  (3) Although the plurality of bus bars 30 and 70 are assembled to the printed circuit boards 11 and 51 in the above-described embodiment, the number of bus bars is not necessarily plural.

  (4) In the above embodiment, the inlay as the positioning protrusion is press-fitted into the bus bar and fixed. However, for example, it may be fixed by a brazing material such as solder, or the positioning protrusion may be formed by pressing the bus bar. It may be formed integrally with the bus bar.

  (5) In the above embodiment, the end faces 36A, 76A of the protrusions 36, 76 are set to be flush with the surface of the printed circuit board 11, 51. It is good also as a structure protruded from the surface of the board | substrates 11 and 51, or a structure dented.

DESCRIPTION OF SYMBOLS 10,50 ... Circuit structure 11,51 ... Printed circuit board 12,52 ... Positioning through hole 20,60 ... Electronic component 30,70 ... Bus bar 31,71 ... Bus bar through hole 35,75 ... Inlay (conductive member)
36, 76 ... Projection (positioning projection)
36A, 76A ... end face (protruding end face)
52A ... 1st positioning through hole 70A ... 1st bus bar 72 ... Bending part

Claims (7)

A circuit structure comprising a printed circuit board in which a circuit made of a conductive metal material is formed on an insulating substrate, and a bus bar laminated on the printed circuit board,
A positioning through hole is formed in the printed circuit board,
In the bus bar, a position corresponding to the positioning through hole is provided with a positioning protrusion that is press-fitted into the positioning through hole and positions the bus bar with respect to the printed circuit board. Circuit construct. 2. The circuit structure according to claim 1, wherein the positioning protrusion is a conductive member that is press-fitted into a bus bar through-hole provided in the bus bar and protrudes from a surface of the bus bar. The circuit structure according to claim 1, wherein the positioning protrusion is a bent portion obtained by bending a part of the bus bar. 4. The circuit structure according to claim 1, wherein a plurality of the bus bars are provided, and one or more positioning protrusions are provided for each of the bus bars. 5. . 5. The circuit structure according to claim 1, wherein a surface of the positioning protrusion perpendicular to the press-fitting direction and the positioning through hole are triangular or quadrangular. . The positioning protrusion has a connecting surface in which the protruding end surface is flush with the surface of the insulating substrate in a state where the protruding portion is press-fitted into the positioning through-hole, and a terminal of the electronic component is formed on the connecting surface. The circuit structure according to claim 1, wherein the circuit structure is electrically connected. The circuit structure according to claim 6, wherein a plurality of the bus bars are provided, and the terminals of the electronic component are connected between the different bus bars.

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