WO2012063682A1

WO2012063682A1 - Circuit module having attached metal case, circuit module assembly having attached metal case, and method for producing circuit module having attached metal case

Info

Publication number: WO2012063682A1
Application number: PCT/JP2011/075190
Authority: WO
Inventors: 昌由高木; 隆学高森
Original assignee: 株式会社村田製作所
Priority date: 2010-11-08
Filing date: 2011-11-01
Publication date: 2012-05-18
Also published as: JP5348442B2; JPWO2012063682A1

Abstract

Provided is a more compact circuit module having an attached metal case. The circuit module having an attached metal case is characterized by being provided with: a circuit board having at least four sides; an electronic component mounted to the circuit board; and a metal case attached to the circuit board, covering the electronic component. The circuit module having an attached metal case is further characterized by a metal case land electrode for attaching the metal case being formed in the vicinity of a side on the surface of the circuit board, the metal case land electrode being provided with a main electrode section and a joining material supply section extending in the direction of the side of the circuit board from the main electrode section, and the metal case being joined to the main electrode section by means of the conductive joining material.

Description

Circuit module with metal case, circuit module assembly with metal case, and method for manufacturing circuit module with metal case

The present invention relates to a circuit module with a metal case in which electronic components are mounted on a circuit board.

The present invention also relates to a circuit module assembly with a metal case in which a plurality of circuit modules with a metal case are joined together.

Furthermore, the present invention relates to a method for manufacturing a circuit module with a metal case.

As a conventional circuit module with a metal case, for example, the one described in Patent Document 1 is known. FIG. 6 shows the circuit module 90 with a metal case. In the circuit module 90 with a metal case,

electronic components

101a, 101b, and 101c are mounted on a circuit board 100 on which a metal case land electrode 100a having a ground potential is formed. And the lower end 102a of the side wall of the metal case 102 provided with the ceiling is joined to the land electrode 100a for the metal case of the circuit board 100 so as to cover these

electronic components

101a, 101b, and 101c.

Solder is used for joining the lower end 102a of the side wall and the land electrode 100a for the metal case. When applying solder paste onto the metal case land electrode 100a, the metal case land electrode 100a and the electronic component are avoided in order to avoid interference between the coating nozzle and the electronic components 101a and 101c already mounted on the substrate. A considerable clearance is provided between 101a and 101c.

JP 2007-67002 A

In such a circuit module 90 with a metal case, when the solder paste for mounting the metal case is applied to the land electrode 100a for the metal case, the coating nozzle and the electronic components 101a and 101c already mounted on the substrate interfere with each other. In order to avoid this, it is necessary to provide a considerable clearance between the wiring land and these parts. However, this clearance has been an obstacle to downsizing the circuit module.

In view of such circumstances, the present invention provides a metal case land electrode for joining a circuit board and a metal case, and a metal case land capable of reducing a clearance to an electronic component mounted in the vicinity thereof. It is an object of the present invention to provide a circuit module with a metal case provided with a bonding material supply unit for supplying a conductive bonding material to an electrode.

In order to solve the above problems, the present invention provides a circuit module with a metal case configured as follows.

A circuit module with a metal case according to the present invention includes a circuit board having at least four sides, an electronic component mounted on the circuit board, and a metal case that covers the electronic component and is attached to the circuit board. A metal case land electrode for attaching a metal case is formed in the vicinity of the side on the surface, and the metal case land electrode extends from the main electrode part to the side of the circuit board from the main electrode part. And a supply case, wherein the metal case is bonded to the main electrode portion by a conductive bonding material.

According to the above configuration, conventionally, a nozzle for applying a bonding material such as solder paste and an electronic component mounted on a substrate are provided between a land electrode for a metal case and the electronic component in order to avoid interference. The clearance can be made as small as possible and can be eliminated in some cases. As a result, the circuit module with a metal case can be reduced in size.

Note that, for example, solder or a conductive adhesive can be used as the conductive bonding material.

Further, the bonding material supply unit may be formed so as to reach the side of the circuit board. In this case, since the distance between the electronic component mounted on the circuit board and the bonding material supply unit increases, the bonding material application nozzle interferes with the electronic component when applying the bonding material to the bonding material supply unit. There is nothing to do.

Also, the bonding material supply unit may be provided with a plurality of line-shaped electrodes. In this case, the liquid bonding material is smoothly supplied from the bonding material supply unit to the main electrode unit by capillary action.

Note that the metal case land electrode may be provided in the vicinity of two opposite sides of the circuit board, or may be provided in all of the vicinity of the four sides. A plurality of metal case land electrodes may be provided in the vicinity of one side.

Also, a plurality of the above-described circuit modules with a metal case can be joined to form a circuit module assembly with a metal case. In addition, the circuit module assembly with a metal case is not only an intermediate manufactured in the middle of manufacturing a circuit module with a metal case, but also from an electronic component manufacturer that manufactured the circuit module assembly with a metal case. There are cases where the product is sold as a product to an electrical / electronic equipment manufacturer that manufactures electrical / electronic equipment using a circuit module with a case.

In the circuit module assembly with a metal case, a discard area that does not belong to any circuit board is provided between the circuit board of one circuit module and the circuit board of another adjacent circuit module. It is preferable to make it. In this case, it becomes possible to provide a part or all of the bonding material supply section in the disposal area, and after dividing each circuit module with a metal case, the disposal area is discarded to attach the metal case. The remaining unnecessary bonding material of the used bonding material can be discarded at the same time, and no unnecessary bonding material remains in the circuit module with a metal case.

According to the present invention, the circuit module with a metal case can be downsized.

FIG. 1A is an exploded perspective view showing a circuit module assembly 10a with a metal case according to the first embodiment of the present invention. FIG.1 (b) is a perspective view which shows the circuit module aggregate | assembly 10a with a metal case which concerns on 1st Embodiment of this invention. It is a top view which shows the circuit board aggregate | assembly 11a of the circuit module aggregate | assembly 10a with a metal case which concerns on 1st Embodiment of this invention. It is a top view showing circuit module 10 with a metal case concerning a 1st embodiment of the present invention. It is a top view which shows the circuit board aggregate | assembly 11a of the circuit module assembly with a metal case which concerns on 2nd Embodiment of this invention. Fig.5 (a) is a top view which shows the circuit board aggregate | assembly 11a of the circuit module assembly with a metal case which concerns on 3rd Embodiment of this invention. FIG.5 (b) is a top view which shows the circuit board aggregate | assembly 11a concerning the modification of Fig.5 (a). It is a disassembled perspective view which shows the conventional circuit module 90 with a metal case.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1A and FIG. 1B show a circuit module assembly 10a with a metal case according to this embodiment. FIG. 2 shows a circuit board assembly 11a of the circuit module assembly 10a with the metal case. Further, FIG. 3 shows a circuit module 10 with a metal case according to the present embodiment obtained by dividing the circuit module assembly 10a with a metal case.

Hereinafter, the structure of the circuit module assembly 10a with the metal case and the method of manufacturing the circuit module 10 with the metal case will be described to clarify these structures.

First, a circuit board assembly 11a in which a plurality of circuit boards 11 are integrated to prepare a plurality of circuit modules 10 with metal cases is prepared. As shown in FIGS. 1A and 1B, in the present embodiment, the circuit board assembly 11a is integrated with four circuit boards 11 for manufacturing four circuit modules with metal cases. It has become.

The circuit board assembly 11a is made of, for example, ceramic, glass, epoxy resin, or the like.

The circuit board assembly 11a is virtually provided with a dividing line 12 for later division into individual circuit modules 10 with metal cases. The dividing line 12 corresponds to the side of the circuit board 11 of each circuit module 10 with a metal case. In the present embodiment, two dividing lines 12 are formed in parallel between adjacent circuit boards 11 with a discard region 18 interposed therebetween (see FIG. 2).

The circuit board assembly 11a is virtually provided with a metal case mounting line 17b for mounting a metal case 17 described later.

On the surface of the circuit board assembly 11a, although not shown, electronic component land electrodes for mounting electronic components are formed.

Also, the metal case land electrode 13 is formed on the metal case mounting line 17b on the surface of the circuit board assembly 11a. The metal case land electrode 13 is formed by integrally forming a main electrode portion 13a and a bonding material supply portion 13b extending from the main electrode portion 13a. The main electrode portion 13a is formed on the metal case attachment line 17b. The bonding material supply unit 13b is formed by arranging a plurality (three) of line-shaped electrodes side by side. The leading end of the bonding material supply unit 13 b exceeds the adjacent dividing line 12 and reaches the disposal area 18. In addition, the shape of the joining member supply part 13b may be one planar electrode instead of a plurality of line-shaped electrodes. The metal case land electrode 13 is preferably grounded to the ground. In this case, the noise received by the metal case 17 can be discharged to the ground.

The electronic component 16 is mounted on the circuit board assembly 11a having such a structure. Specifically, the electronic component 16 is attached to the electronic component land electrode (not shown) of the circuit board assembly 11a by reflow soldering. For example, a capacitor, a resistor, a filter, an inductor, an IC, or the like is used as the electronic component 16.

Next, a conductive bonding material is applied to the application region 14 where the bonding material supply portion 13b of the metal case land electrode 13 of the circuit board assembly 11a is formed. In this embodiment, a solder paste (paste solder) is applied as a conductive bonding material. Instead of this, a liquid conductive adhesive may be applied.

At this time, since the electronic component 16 already mounted and the application region 14 have a relatively large distance, the coating nozzle for applying the solder paste does not interfere with the electronic component 16.

Next, the circuit board assembly 11a is heated to melt the solder paste applied to the bonding material supply unit 13b. As a result, the molten solder flows from the bonding material supply unit 13b to the main electrode unit 13a. In order to prevent the electronic component 16 bonded to the electronic component good land electrode from being detached when the circuit board assembly 11a is heated, the solder for mounting the electronic component 16 is a solder for attaching a metal case. It is desirable to use one having a higher melting temperature. When a liquid conductive adhesive is used in place of the solder paste, the conductive adhesive is supplied from the bonding material supply part 13b to the main electrode part 13a without heating the circuit board assembly 11a. To flow.

Next, the metal case 17 is arranged on each metal case attachment line 17b of the circuit board assembly 11a. The metal case 17 is made of a case that is formed by bending a thin metal plate or the like, and has four side walls 17a. The side wall 17 a may be provided with a notch so that the solder can easily spread inside the metal case 17.

Next, the circuit board assembly 11 a is cooled or naturally cooled to solidify the molten solder on the main electrode portion 13 a of the metal case land electrode 13. As a result, the lower end portion of the side wall 17a of the metal case 17 is soldered to the main electrode portion 13a. In addition, when a liquid conductive adhesive is used as the conductive bonding material and it is a thermosetting conductive adhesive, the conductive adhesive is heated in reverse. Is cured, the lower end portion of the side wall 17a of the metal case 17 is attached to the main electrode portion 13a.

Finally, the circuit module assembly 10a with the metal case is divided by the dividing line 12 of the circuit board assembly 11a to complete the individual circuit modules 10 with the metal case as shown in FIG.

In the circuit module 10 with a metal case configured as described above, the application area 13a where the solder paste for attaching the metal case is applied can be kept away from the electronic component 16 already mounted on the substrate. Therefore, in order to avoid interference between the solder paste coating nozzle and the electronic component mounted on the substrate, conventionally, the clearance provided between the wiring land and the electronic component is made as small as possible. It can be lost. As a result, the circuit module with a metal case can be reduced in size.

As mentioned above, although the manufacturing method of the circuit module with a metal case, the circuit module aggregate with a metal case, and the circuit module with a metal case according to the first embodiment has been described, the present invention is not limited to the above-described contents, Various changes can be made along the spirit of the invention.

For example, the number of circuit boards 11 formed in the circuit board assembly 11a is not limited to four as described above, and may be more or less. Alternatively, one circuit board 11 may be prepared without using the circuit board assembly 11a, and a circuit module with a metal case may be manufactured using the circuit board 11.

Further, the number of metal case land electrodes 13 provided on the circuit board 11 and the positions to be provided are arbitrary, and are not limited to the above-described contents. For example, the metal case land electrodes 13 may be formed in the vicinity of the four sides of the circuit board 11. Further, two metal case land electrodes 13 may be formed in the vicinity of one side of the circuit board 11.
[Second Embodiment]
FIG. 4 shows a circuit board assembly 11a of a circuit module assembly with a metal case according to the second embodiment.

The circuit board assembly 11a of the circuit module assembly with a metal case of the present embodiment has a length of the bonding material supply portion 23b of the metal case land electrode 23 as compared with the substrate assembly 11a of the first embodiment described above. It is short and its tip does not reach the dividing line 12. In the figure, reference numeral 23a denotes a main electrode portion, and 24 denotes a coating region.

According to the structure of the present embodiment, when dividing by the dividing line 12 of the circuit board assembly 11a, the bonding material supply portion 23b of the metal case land electrode 23 is not cut, so that the electrode scraps are scattered. There is no.
[Third Embodiment]
FIG. 5A shows a circuit board assembly 11a of a circuit module assembly with a metal case according to the third embodiment.

In the circuit module assembly with a metal case of the present embodiment, the bonding material supply portions 33b of the metal case land electrodes 33 formed on the circuit boards 11 adjacent to the circuit board assembly 11a are connected to each other. It is characterized by being. In the figure, 33a is a main electrode portion, and 34 is a coating region.

In the present embodiment, the bonding material can be applied to the bonding material supply portions 33b of the two metal case land electrodes 33 by applying the bonding material to one application region 34. Productivity of circuit modules with cases is improved.

In addition, in the circuit module assembly with a metal case of the third embodiment shown in FIG. 5A, the disposal area 18 formed between the adjacent circuit boards 11 is as shown in FIG. May be omitted. In this case, the number of steps for dividing the circuit board assembly 11a can be reduced, and the productivity can be improved. Further, the number of circuit boards 11 that can be obtained from one circuit board assembly 11a can be increased, and the cost can be reduced.

10: Circuit module with metal case 10a: Circuit module assembly with metal case 11: Circuit board 11a: Circuit board assembly 12: Dividing

lines

13, 23, 33: Land electrodes for

metal case

13a, 23a, 33a:

Main electrode portion

13b, 23b, 33b: Bonding

material supply unit

14, 24, 34: Application region 16: Electronic component 17: Metal case 17a: Side wall 17b: Metal case attachment line 18: Waste region

Claims

A circuit module comprising a circuit board having at least four sides, an electronic component mounted on the circuit board, and a metal case attached to the circuit board so as to cover the electronic component,
A metal case land electrode for attaching the metal case is formed in the vicinity of the side on the surface of the circuit board,
The metal case land electrode includes a main electrode portion and a bonding material supply portion extending from the main electrode portion in the direction of the side of the circuit board,
A circuit module with a metal case, wherein the metal case is bonded to the main electrode portion with a conductive bonding material.
The circuit module with a metal case according to claim 1, wherein the conductive bonding material is solder or a conductive adhesive.
The circuit module with a metal case according to claim 1 or 2, wherein the bonding material supply unit reaches the side of the circuit board.
The circuit module with a metal case according to any one of claims 1 to 3, wherein the bonding material supply section is formed by arranging a plurality of line-shaped electrodes.
The circuit board has four sides, and the metal case land electrode is formed in the vicinity of two opposing sides of the four sides of the circuit board, respectively. The circuit module with a metal case according to any one of claims 1 to 4.
6. The circuit board according to claim 1, wherein the circuit board has four sides, and the land electrode for the metal case is formed in the vicinity of the four sides of the circuit board. The circuit module with a metal case described in item 1.
The metal case according to any one of claims 1 to 6, wherein a plurality of land electrodes for a metal case are formed in the vicinity of one of the sides of the circuit board. Circuit module.
A circuit module assembly with a metal case, wherein a plurality of circuit modules according to any one of claims 1 to 7 are joined.
Among the plurality of joined circuit modules, the joining material supply part of one circuit module and the joining material supply part of another adjacent circuit module are connected to each other. A circuit module assembly with a metal case according to claim 8.
Among the plurality of joined circuit modules, a discard area that does not belong to any circuit board between the circuit board of one circuit module and the circuit board of another adjacent circuit module. And the bonding material supply part of the one circuit module and the bonding material supply part of the other one adjacent circuit module respectively reach the disposal area. A circuit module assembly with a metal case according to claim 8 or 9.
Preparing a circuit board assembly in which a plurality of circuit boards having at least four sides are joined; and
A metal for forming an electronic component land electrode for mounting an electronic component on each surface of the circuit board and attaching the metal case in the vicinity of the side on each surface of the circuit board Forming a case land electrode comprising a main electrode portion and a bonding material supply portion extending from the main electrode portion in the direction of the side of the circuit board;
Mounting an electronic component on the electronic component land electrode of the circuit board;
Applying paste-like solder or liquid conductive adhesive to the bonding material supply section of the circuit board;
Heating the circuit board assembly to melt the paste-like solder and flowing to the main electrode part, or flowing the liquid conductive adhesive to the main electrode part; and
A step of disposing a metal case in a state of covering the electronic component on the melted solder or the liquid conductive adhesive that has flowed to the main electrode portion of the circuit board;
Solidifying the molten solder or curing the liquid conductive adhesive to attach the metal case to each of the circuit boards;
Dividing the circuit board assembly to obtain individual circuit modules with metal cases, and a method for producing a circuit module with metal cases.
12. The circuit with a metal case according to claim 11, wherein the electronic component land electrode and the metal case land electrode are respectively formed in advance on the circuit board of the circuit board assembly. Module manufacturing method.