JP4822050B2 - Circuit structure and manufacturing method thereof - Google Patents

Description

  The present invention relates to a circuit structure formed by attaching a bus bar to a circuit board.

  For example, there is an electrical connection box mounted on an automobile having a structure in which a circuit structure is housed in a case. The circuit configuration body includes a circuit board, a bus bar arranged along the circuit board, and electronic components such as relays and semiconductor elements mounted on the circuit board. These electronic components have a structure in which a plurality of lead portions project from a synthetic resin package, and the lead portions are connected to a conductor circuit or bus bar formed on the surface of the circuit board to constitute a control circuit. . In order to connect the lead part to the bus bar arranged on the back side of the circuit board, as disclosed in Patent Document 1 below, an opening is formed in the circuit board and the bus bar is provided on the back side. A configuration is conceived in which a part of the electronic component mounted on the surface of the circuit board is connected to the bus bar through the opening in advance so that a part is exposed from the opening.

  By the way, as an electronic component for switching mounted on the circuit board, depending on the model of the electronic junction box, a relay may be used, a semiconductor element such as an FET may be used, or they may be mixed. . Both the relay and semiconductor element have a structure in which multiple lead parts protrude from the package, but the layout and position of the lead parts differ, so circuit boards and bus bars are shared between different models. Can not do it.

  In order to explain the circumstances, an example in which the relay 1 is mounted is shown in FIG. The relay 1 is provided with a pair of control lead portions 1A and three load lead portions 1B on the lower surface of the package 2, and each control lead portion 1A is a conductor circuit formed on the surface of the circuit board 3. Connected to 3A. The circuit board 3 is formed with three openings 3A corresponding to the load leads 1B, and two bus bars 4 are routed on the back surface of the circuit board 3. When the relay 1 is placed on the circuit board 3, each load lead 1 </ b> B of the relay 1 is accommodated in each opening 3 </ b> A and comes into contact with the bus bar 4. Implementation is complete.

  On the other hand, what is shown in FIG. 12 is an example in which the semiconductor element 5 is mounted. A drain electrode 5 </ b> A is provided as a lead portion on the lower surface of the package 6 of the semiconductor element 5, and a source electrode 5 </ b> B and a gate electrode 5 </ b> C are provided as lead portions from the side surface of the package 6. A conductive circuit 7A is formed on the surface of the circuit board 7 corresponding to the gate electrode 5C, an opening 7B is formed at a position corresponding to the package 6, and an opening 7C is formed at a position corresponding to the source electrode 5B. A bus bar 8 is wired on the back surface of the circuit board 3. When the semiconductor element 5 is set so that the package 6 is accommodated in the opening 7B, the drain electrode 5A comes into contact with one bus bar 8 and the source electrode 5B comes into contact with the other bus bar 8. To complete the mounting of the semiconductor element 5.

Because of the above configuration, it is clearly impossible to mount the semiconductor element 5 using the circuit board 3 or bus bar 4 group for the relay 1, and a dedicated circuit board or bus bar group must be prepared respectively. There wasn't.
In addition, since only the bus bar is shared, it is possible to use the bus bar 4 group for the relay 1 by replacing the circuit board 7 according to the configuration of the lead portions 5A to 5C in a model in which the semiconductor element 5 is mounted. Then, since the state shown in FIG. 13 is obtained, the connection of the drain electrode 5A is incomplete, which is also impossible to realize.
JP 2003-164039 A

  The present invention has been completed based on the above situation, and an object of the present invention is to provide a circuit structure that can reduce the manufacturing cost by sharing the bus bar configuration among models having different electronic components to be mounted. And

As means for achieving the above object, the invention of claim 1 is characterized in that a circuit board in which an opening is formed at a predetermined position and a circuit board that is superposed along the circuit board and connected to a position corresponding to the opening. A bus bar having a portion and an electronic component having a lead portion protruding from the package and connected to the connection portion of the bus bar through the opening, and the circuit board is overlapped in the bus bar. On the surface, there is a connection part for another model that can connect a lead part of an electronic component different from the electronic part when it is overlapped with a circuit board for another model in which the opening is formed at a position different from the opening. It has a feature where it is provided.

  In this configuration, when manufacturing other models with different electronic components to be mounted, it is possible to replace only the circuit board with one with an opening arrangement designed for that model, and use the bus bar group in common. it can. When the electronic component is set on the circuit board, each lead portion is inserted into each opening portion of the circuit board and comes into contact with the connection portion for other models of the bus bar.

  In the first aspect of the present invention, a conductive circuit is formed on the surface of the circuit board opposite to the bus bar, and a part of the lead part of the electronic component is connected to the conductive circuit. Can do.

  Further, in the invention of claim 1 or claim 2, a tab portion that functions as a terminal fitting of the connector may be integrally provided at the tip end portion of the bus bar, and a connection portion of an electrical component is inserted and held. The connection holding part may be provided integrally.

  According to the present invention, the bus bar group can be used in common among different models, so that a significant cost reduction can be achieved.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to FIGS. The electrical connection box 100 of this embodiment is used by being mounted on an automobile or the like, and is provided between a battery (not shown) and electrical components (not shown) such as a lamp and an audio, and is supplied from the battery. Distributes and supplies power to each electrical component, and controls switching of the power supply.

  1 and 2 are a perspective view and a cross-sectional view of the electrical junction box 100 in the present embodiment. In both figures, the electric junction box 100 is drawn with its front side facing upward, but when mounted on an automobile or the like, the vertical right side of FIG. 1 is the upper side and the left front side is the lower side. It can be attached to the body in the direction of the mold.

  As shown in FIG. 2, the electrical junction box 100 includes a circuit structure 10 and a case 20 that houses the circuit structure 10. As shown in FIG. 3, the circuit structure 10 includes a circuit board 11, a plurality of bus bars 12 bonded to the back surface (lower surface in the figure) of the circuit board 11, and the front surface side (upper surface in the figure) of the circuit board 11. The relay 13 and the semiconductor switching element 14 which are electronic components mounted on the side) are configured.

  As shown in FIG. 2, the case 20 that accommodates the circuit structure 10 includes a frame body 30, a heat dissipation plate 40 that is fixed to the frame body 30 so as to close the opening on the back side, and the frame body 30. And a cover 50 assembled so as to close the opening on the surface side (the side opposite to the heat radiating plate 40).

  The frame body 30 is made of an insulating material such as a synthetic resin, and is configured by combining two parts of the frame main body 31 and the auxiliary frame body 32, and extends over the entire circumference of the circuit configuration body 10 along the periphery of the circuit board 11. It is formed so as to surround continuously. The auxiliary frame body 32 and the frame body 31, that is, the frame body 30 are fixed to the surface of the heat sink 40 with an adhesive (not shown).

  The heat radiating plate 40 is made of metal, is generally similar to the circuit board 11 and has a shape that is slightly larger than the circuit board 11, and a stepped shape from the upper edge of the plate body 41 to the upper side of the back surface. An extending plate-like bracket 42 is integrally provided. The electrical junction box 100 of this embodiment is fixed to the vehicle body by bolts (not shown) via the bracket 42.

  A first connector housing 70 is assembled to the upper part (right side in FIG. 2) of the frame 30 and a second connector housing 80 is assembled to the lower part (left side in FIG. 2). It opens to the left (toward the left in FIG. 2).

  Now, the bus bar 12 bonded to the back surface of the circuit board 11 is formed by punching a metal plate excellent in conductivity, and forms a predetermined conductive path that becomes a power circuit. As shown in FIG. 3, a fuse terminal 12 </ b> A that is a connection holding part for inserting and connecting a connection part of an electrical component such as a fuse (not shown) to the upper edge and the lower edge of each bus bar 12. And the tab part 12B which is inserted in the said 2nd connector housing 80 and functions as a terminal metal fitting of a connector is provided.

  In the present embodiment, as electronic components mounted on the circuit board 11, for example, as shown in FIG. 3, three relays 13 and five semiconductor switching elements (FETs) 14 are used. The semiconductor switching element 14 has the same shape as the conventional one, and as shown in FIG. 3, a drain electrode 14B as a lead portion is arranged on the lower surface of the package 14A, and a source electrode 14C as a lead portion is formed from the side surface of the package 14A. The gate electrode 14D is protruded. The relay 13 has the same shape as the conventional one, and as shown in FIGS. 3 and 9, two control lead portions 13B and three load lead portions 13C to 13E are led out from the lower surface of the package 13A. (The load lead portions 13C and 13D are commonly connected internally).

  An upper right half portion including three semiconductor switching elements 14 in the circuit structure 100 is shown in an enlarged manner in FIG. As shown here, openings 15A and 15B are formed in the circuit board 11 in accordance with the positions of the respective semiconductor switching elements 14 and their respective electrodes 14B to 14D.

  These openings 15 </ b> A and 15 </ b> B clearly appear in FIG. 5 drawn with the semiconductor switching element 14 removed. That is, the upper right half of the circuit board 11 accommodates an opening 15A having a size capable of accommodating the package 14A and the source electrode 14C protruding upward from the package 14A, corresponding to each semiconductor switching element 14. Possible openings 15B are formed continuously. On the other hand, a conductor circuit 11A formed by a known printed wiring means is provided on the surface of the circuit board 11, and a soldering land is provided at the tip of the conductor circuit 11A corresponding to the gate electrode 14D of the semiconductor switching element 14. It has been.

  On the other hand, the shape of each bus bar 12 appears clearly in FIG. 6 in which the circuit board 11 is removed. In the drawing, the bus bar 12 depicted as the largest one connected in a reverse L shape at the right end and the lower edge is connected to, for example, a battery positive electrode of a vehicle, and has a connector tab portion 12C at the end. The drain electrode 14B of each semiconductor switching element 14 is connected to the common line 12D connected to the lower edge portion by soldering (see the two-dot chain line in FIG. 6). Further, the source electrodes 14C of the three semiconductor switching elements 14 shown in the figure are connected to the electrode connection portions 12E provided on the three different bus bars 12, respectively. The switching element 14 controls electrical disconnection between the common line 12D and the three bus bars 12.

  Of the three bus bars 12, two of the three bus bars 12 connected to the left semiconductor switching element 14 are provided with a connecting portion 12F for another model continuously from the portion connected to each source electrode 14C. It has been. The other-model connecting portion 12F is clarified by adding cross-hatching in FIG. 6, but is for connecting load lead portions 13C to 13E of the relay 13 to be described later. Since it is provided continuously on the left and right sides of the connecting portion 12E to which the source electrode 14C is connected and nothing is connected when the semiconductor switching element 14 is used, it is a useless portion in that case.

  In order to manufacture the electrical junction box 100 of the present embodiment, the circuit component 10 is first assembled. First, the circuit board 11 on which no electronic components are mounted and the bus bar 12 are bonded with an adhesive (not shown). Then, the bus bar 12 and the heat radiating plate 40 are bonded together. At this time, since the switching member 13 is not mounted on the circuit board 11, the bus bar 12 and the heat sink 40 can be firmly bonded by pressing the surface of the circuit board 11 over a wide area. Then, electronic components such as the relay 13 and the semiconductor switching element 14 are mounted on the circuit board 11 by, for example, reflow soldering, etc., and thereby the circuit structure 10 is assembled.

  In the above description, as shown in FIG. 3, the model in which the three relays 13 and the five semiconductor switching elements 14 are mounted on the circuit board 11 has been described. However, depending on the model, a part of the semiconductor switching element 14 group may be replaced with the relay 13. In such a case, the position and length of the lead portion led out of the package are completely different between the relay 13 and the semiconductor switching element 14, so the position of the connection portion with the bus bar is different, and thus not only the circuit board. The bus bar also had to be redesigned and manufactured for each model.

  On the other hand, in this embodiment, the bus bar 12 is formed with the connection part 12F for other models, so that the bus bar 12 can be shared with different models. The circumstances will be described next.

Also in this embodiment, the circuit board is designed and manufactured exclusively for the different model as in the conventional case. FIG. 8 shows the circuit board 16 of another model (corresponding to a circuit board for other models) , and this figure shows a portion where two relays 13 and one semiconductor switching element 14 are mounted ( Corresponding to FIG. 4). The mounting portion of the two relays 13 provided on the left side of the circuit board 16 is formed with openings 16A corresponding to the three load leads 13C for each relay 13 so as to be able to pass therethrough. Has been. A plurality of conductor circuits 16B having solder lands corresponding to the two control terminals 13B of each relay 13 are formed on the surface of the circuit board 16.

  When such a circuit board 16 is overlapped with the bus bar 12 and bonded at a predetermined position, the connection parts 12F for the other models of the two bus bars 12 are exposed through the openings 16B of the circuit board 16, as shown in FIG. Will do. Therefore, as shown in FIG. 9, when the relay 13 is disposed at a predetermined position on the circuit board 16, the control lead portion 13 </ b> B contacts the conductor circuit 16 </ b> B on the surface of the circuit board 16, and the load lead portion 13 </ b> C is connected to the circuit board 16. Is fitted into the opening 16A of the bus bar 12 and comes into contact with the connecting portion 12F for other models of the bus bar 12.

  Therefore, according to this embodiment, as shown in FIG. 4, when manufacturing a model in which three semiconductor switching elements 14 are arranged in the region shown in FIG. 4, a circuit board for that model is manufactured. 11 is used to affix the bus bar 12 group at a predetermined position on the back surface thereof. Further, as shown in FIG. 8, when manufacturing a model in which two relays 13 and one semiconductor switching element 14 are arranged in the region shown in FIG. 8, a circuit board 16 for the model is manufactured. And the same group of bus bars 12 as the above-mentioned model may be pasted at a predetermined position on the back surface thereof. For this reason, the same bus bar 12 group can be used for two models with different electronic parts to be mounted, and it is not necessary to design and manufacture the bus bar group for each model, and the cost can be reduced by sharing the parts. .

  In addition, although the example corresponding to two models was shown in the said embodiment, it is good also as a structure corresponding to three or more models by providing more connection parts 12F for other models. In addition, the electronic components to be mounted are not limited to the relay 13 and the semiconductor switching element 14, and an electronic component having a structure in which a lead portion protrudes from the package can be generally used.

The perspective view of the electrical junction box in this embodiment Side view of electrical junction box Perspective view of circuit structure Partial plan view of the circuit structure Partial plan view showing a circuit structure before mounting electronic components Plan view showing bus bar group FIG. 4 is an enlarged sectional view taken along line VII-VII. Partial plan view of a circuit structure (before mounting electronic components) showing an example using circuit boards of different models Partial plan view showing circuit components of different models Fig. 9 is an enlarged sectional view taken along line IX-IX. Enlarged perspective view of models with relays mounted in the prior art An enlarged perspective view of a model in which a semiconductor switching element is mounted in the prior art Enlarged perspective view showing defects when bus bars are shared in the prior art

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Circuit structure 11, 16 ... Circuit board 12 ... Bus bar 12E ... Connection part 12F ... Connection part for other models 13 ... Relay (electronic component)
14 ... Semiconductor switching element (electronic component)
13A, 14A ... Package 13B-13E, 14B-14D ... Lead part 15A, 15B, 16A ... Opening

Claims (5)

A circuit board in which an opening is formed at a predetermined position, a bus bar that is arranged along the circuit board and has a connection portion at a position corresponding to the opening, and a lead that protrudes from the package. And an electronic component connected to the connection portion of the bus bar through the opening, and an opening is formed at a position different from the opening on the surface of the bus bar on which the circuit board is stacked . A circuit structure comprising a connection part for another model that enables connection of a lead part of an electronic component different from the electronic component when the circuit board is overlapped with the circuit board for another model. 2. The circuit according to claim 1, wherein a conductor circuit is formed on a surface of the circuit board opposite to the bus bar side, and a lead portion of a part of the electronic component is connected to the conductor circuit. Construct. The circuit structure according to claim 1 or 2, wherein a tab portion functioning as a terminal fitting of a connector is integrally provided at a front end portion of the bus bar. The circuit structure according to claim 1 or 2, wherein a connection holding portion for inserting and holding a connection portion of an electrical component is integrally provided at a front end portion of the bus bar. A circuit board in which an opening is formed at a predetermined position, a bus bar that is arranged along the circuit board and has a connection portion at a position corresponding to the opening, and a lead that protrudes from the package. And a circuit component including an electronic component connected to the connection portion of the bus bar through the opening, the surface of the bus bar on which the circuit board is overlapped , the opening A connection portion for another model that enables connection of a lead portion of an electronic component different from the electronic component when overlapped with a circuit board for another model in which an opening is formed at a position different from A method of manufacturing a circuit structure, wherein a circuit structure of another model is manufactured by replacing the circuit board with one having an opening formed at a different position while being common.

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