JP4342985B2 - Electronic circuit unit - Google Patents

Description

  The present invention relates to an electronic circuit unit suitable for use in a transmission / reception unit of a cellular phone.

  FIG. 5 is a plan view showing a conventional electronic circuit unit, FIG. 6 is a cross-sectional view of the main part showing the conventional electronic circuit unit, and FIG. 7 is related to the conventional electronic circuit unit. FIG. 3 is a cross-sectional view of a main part showing a connection structure between adjacent first and second circuits.

  Next, the configuration of the conventional electronic circuit unit will be described with reference to FIGS. 5 to 7. The circuit board 52 provided with the wiring patterns 51 on both the front and back surfaces is divided into first and second regions 53 which are separated from each other. , 54, an electronic component 55 is mounted in the first region 53, and a first circuit 56 such as a transmission / reception switching circuit is formed, and an electronic component 57 is formed in the second region 54. And a second circuit 58 such as a transmission / reception circuit is formed.

  A box-shaped first cover 61 formed by bending a metal plate has a rectangular upper plate 61a and four side plates 61b that are bent downward from four sides of the upper plate 61a. .

  A box-shaped second cover 62 formed by bending a metal plate has a rectangular upper plate 62a and four side plates 62b bent downward from four sides of the upper plate 62a. .

  The first and second covers 61 and 62 are integrated by a flat plate-like connecting portion 63 that connects the lower ends of the side plates 61b and 62b facing each other. Holes 64 are provided.

  The connected first and second covers 61 and 62 cover the first and second circuits 56 and 58, respectively, and the first and second covers 61 and 62 are connected to the circuit board 52. Solder 65 is attached to a grounding conductive pattern (not shown) provided on the circuit board 52 with the entire periphery of the lower portions of the side plates 61b and 62b of the first and second covers 61 and 62 and the connecting portion 63 mounted thereon. It has come to be attached. (For example, see Patent Document 1)

  Further, in such an electronic circuit unit, it is necessary to connect the adjacent first and second circuits 56 and 58. In this case, as shown in FIG. The wiring patterns 51 provided on the lower surface are connected to each other by a connection conductor (through hole) 66.

  However, in this way, in the configuration in which the wiring patterns 51 provided on the upper surface and the lower surface of the circuit board 52 are connected by the connection conductor (through hole) 66, the wiring pattern 51 located on the lower surface is exposed, Not only does the signal leakage increase, but the presence of the connecting conductor (through hole) 66 causes an increase in capacitance and impedance mismatch, resulting in poor performance.

JP 2003-258476 A

  In the conventional electronic circuit unit, since the wiring patterns 51 provided on the upper surface and the lower surface of the circuit board 52 are connected to each other by the connection conductor (through hole) 66, the wiring pattern 51 located on the lower surface is exposed. Not only does the signal leakage increase, but the presence of the connecting conductor (through hole) 66 causes a problem that the capacity is increased and impedance mismatching occurs, resulting in poor performance.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electronic circuit unit with less signal leakage and good performance.

As a first means for solving the above problems, a circuit board in which electronic components are mounted in first and second regions separated from each other to form first and second circuits; a top plate to cover the respective second circuit, each configured from the bent side plate from the top plate downwardly, first, of the second lower portion of the side plate is attached by soldering to the circuit board A cover , a conductive pattern for connection provided on the upper surface of the circuit board across the first and second regions, and connecting the first and second circuits; and the conductive pattern for connection on the upper surface of the circuit board. an insulating layer formed to cover the pattern, the first, provided on the second cover, together with the connecting the first, lower portion of the side plates to each other facing the second cover, said insulating layer It said circuit group in a state of being positioned above In the Rukoto soldered, and a structure in which a connecting portion to shield the conductive pattern for the connection via the insulating layer on the upper surface of the circuit board.

Further, as a second solution, a slight gap is provided between the upper surface of the insulating layer and the lower surface of the connecting portion.
As a third solution, the insulating layer is formed of a solder resist.

  As a fourth solution, a grounding conductive pattern is provided on the upper surface of the circuit board so as to be opposed to the lower surface of the connecting portion, excluding the connecting conductive pattern, and the lower surface of the connecting portion. The connecting portion and the grounding conductive pattern are soldered with a gap between the grounding conductive pattern and the grounding conductive pattern.

An electronic circuit unit according to the present invention includes a circuit board in which electronic components are mounted in first and second regions separated from each other to form first and second circuits, and each of the first and second circuits. The circuit board includes first and second covers that are attached to the circuit board by soldering and coupled to each other. The upper surface of the circuit board is provided across the first and second regions, and the first and second covers are provided. A conductive pattern for connecting the two circuits, and an insulating layer formed so as to cover the conductive pattern. The first and second covers are respectively an upper plate and a lower side from the upper plate. And the bottom plate of the side plates facing each other of the first and second covers are connected by a connecting portion, and the connecting portion and the side plate are positioned on the insulating layer. The lower part of the circuit board was soldered to the circuit board.
That is, in the case where the circuit board is covered with the first and second covers connected to each other, the upper surface of the circuit board is covered with the insulating layer and connected to the first and second circuits. Since the connection conductive pattern is shielded by the first and second covers, there is less signal leakage, and the connection conductive pattern has an increased capacity and impedance compared to the conventional connection conductor. Thus, a good performance can be obtained.

  In addition, since a slight gap is provided between the upper surface of the insulating layer and the lower surface of the connecting portion, insulation between the connecting portion and the conductive pattern for connection is ensured, and a product with good quality can be obtained.

  In addition, since the insulating layer is formed of a solder resist, it is easy to form, and a product with good productivity and low cost can be obtained.

  In addition, a grounding conductive pattern is provided on the upper surface of the circuit board so as to face the lower surface of the connecting portion, with the conductive pattern for connection removed, and a gap is provided between the lower surface of the connecting portion and the grounding conductive pattern. Since the connecting portion and the grounding conductive pattern are soldered in the state of holding, the presence of a gap between the connecting portion and the grounding conductive pattern ensures that the melted solder flows into the gap by capillary action. A certain soldered one can be obtained.

  1 is a plan view showing an electronic circuit unit of the present invention, FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1, and FIG. 3 is a line 3-3 of FIG. FIG. 4 is a plan view of a circuit board according to the electronic circuit unit of the present invention.

  Next, the configuration of the electronic circuit unit of the present invention will be described with reference to FIGS. 1 to 4. A circuit board 1 made of a multilayer board or the like has first and second regions 2 and 3 which are separated from each other. On the upper surface of the circuit board 1, as shown particularly in FIG. 4, the first grounding conductive pattern 4a formed to surround the outer periphery and the first and second regions 2 and 3 are partitioned. It has the 2nd earthing conductive pattern 4c arrange | positioned and the notch part 4b was provided in part.

  Further, on the upper surface of the circuit board 1, the wiring pattern 5 provided in each of the first and second regions 2 and 3 and the position of the notch portion 4b are arranged in the first and second regions 2 and 3. The conductive pattern 6 for connection provided across the board and the insulating layer 7 made of solder resist or the like provided so as to cover the upper surface of the conductive pattern 6 for connection are provided. Is provided.

  In the first area 2, an electronic component 8 is mounted to form a first circuit 9 such as a transmission / reception switching circuit, and in the second area 3, an electronic component 10 is mounted, A second circuit 11 such as a transmission / reception circuit is formed, and the first and second circuits 9 and 11 are connected by the connection conductive pattern 6 so that an RF signal is transmitted by the connection conductive pattern 6. It has become.

  A box-shaped first cover 12 formed by bending a metal plate has a rectangular upper plate 12a and four side plates 12b bent downward from four sides of the upper plate 12a. The box-shaped second cover 13 formed by bending a metal plate has a rectangular upper plate 13a and four side plates 13b bent downward from four sides of the upper plate 13a.

  The first and second covers 12 and 13 are integrated by a flat plate-like connecting portion 14 that connects the lower ends of the side plates 12b and 13b facing each other, and the lower surfaces are flush with each other. The first and second covers 12 and 13 connected by the connecting portion 14 cover the first and second circuits 9 and 11, respectively, and the first and second covers 12 and 13 are side plates. The entire circumference of the lower part of 12b and 13b is soldered to the first grounding conductive pattern 4a, and the connecting portion 14 is soldered to the second grounding conductive pattern 4c provided on the circuit board 1. It is like that.

  At this time, a gap of about 0.2 mm to 0.3 mm is formed between the lower surface of the connecting portion 14 and the upper surface of the insulating layer 7, and the lower surface of the connecting portion 14 and the first grounding conductive material are formed. A gap of about 0.3 mm is provided between the pattern 4c and the melted solder flows into the gap between the lower surface of the connecting portion 14 and the first grounding conductive pattern 4c by capillary action. It has become.

  The soldering of the first and second covers 12 and 13 to the circuit board 1 is performed by first applying cream solder on the first and second grounding conductive patterns 4a and 4c, and then the first and second covers. The lower portions of the side plates 12b and 13b of the second covers 12 and 13 and the lower surface of the connecting portion 14 are placed on the cream solder.

  Thereafter, when the solder paste is transported into the reflow furnace in this state and the solder paste is melted, the outer peripheral portions of the side plates 12b and 13b are in contact with the lower end portions of the side plates 12b and 13b on the first grounding conductive pattern 4a. And the first grounding conductive pattern 4a are soldered, and when the lower ends of the side plates 12b and 13b come into contact with the first grounding conductive pattern 4a, they are insulated from the lower surface of the connecting portion 14. A gap is generated between the upper surface of the layer 7 and between the lower surface of the connecting portion 14 and the second grounding conductive pattern 4c, and a gap between the lower surface of the connecting portion 14 and the second grounding conductive pattern 4c. The melted solder flows into the inside due to a capillary phenomenon, and soldering 15 is performed.

The top view which shows the electronic circuit unit of this invention. Sectional drawing in the 2-2 line of FIG. Sectional drawing in the 3-3 line of FIG. The top view of the circuit board which concerns on the electronic circuit unit of this invention. The top view which shows the conventional electronic circuit unit. Sectional drawing of the principal part which shows the conventional electronic circuit unit. Sectional drawing of the principal part which shows the connection structure of the adjacent 1st, 2nd circuit concerning the conventional electronic circuit unit.

Explanation of symbols

1: circuit board 2: first region 3: second region 4a: first grounding conductive pattern 4b: notch 4c: second grounding conductive pattern 5: wiring pattern 6: connection conductive pattern 7 : Insulating layer 8: Electronic component 9: First circuit 10: Electronic component 11: Second circuit 12: First cover 12a: Upper plate 12b: Side plate 13: Second cover 13a: Upper plate 13b: Side plate 14 : Connection part 15: Solder

Claims (4)

A circuit board on which electronic components are mounted in first and second regions separated from each other to form first and second circuits;
The first, upper plate to cover the respective second circuit, each configured from the bent side plate from the top plate downwardly, first the lower portion of the side plate is attached by soldering to the circuit board A second cover ;
A conductive pattern for connection for connecting the first and second circuits, which is provided across the first and second regions on the upper surface of the circuit board;
An insulating layer formed on the upper surface of the circuit board so as to cover the conductive pattern for connection ;
The first, provided on the second cover, the first, as well as connecting the lower ends of the side plates to each other face of the second cover is soldered to the circuit board in a state of being positioned on the insulating layer A connecting portion that shields the conductive pattern for connection through the insulating layer on the upper surface of the circuit board;
Electronic circuit unit characterized by comprising a. Electronic circuit unit according to claim 1, characterized in that to have a gap between the upper surface and the lower surface of the connecting portion of the insulating layer. The electronic circuit unit according to claim 2 , wherein the insulating layer is formed of a solder resist. The upper surface of the circuit board, in a state except for the connecting conductive patterns, wherein are opposed to the grounding conductor pattern on the lower surface of the connecting portion is provided, and the lower surface of the connecting portion and the ground conductive pattern 4. The electronic circuit unit according to claim 1, wherein the connecting portion and the grounding conductive pattern are soldered in a state where a gap is provided therebetween.

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