JPH1167945A - Electronic circuit module - Google Patents

Abstract

(57) [Problem] In a conventional electronic circuit module, it is difficult to attach a metal case with high positional accuracy while reducing the size of a substrate. SOLUTION: In an electronic circuit module 6 in which a semiconductor element 3 and an electronic component 4 are mounted on a substrate 1 to form an electronic circuit and a metal case 2 is attached so as to cover the electronic circuit, The case 2 is attached by welding to a plurality of case attaching metal members 5 arranged on the substrate 1. The metal case 2 can be mounted on the substrate 1 satisfactorily and with high positional accuracy without increasing the area of the substrate 1, so that the demand for downsizing the electronic circuit module can be sufficiently satisfied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit module which is used for various electronic devices and electronic devices and which is formed by covering an electronic circuit formed on a substrate with a metal case. The present invention relates to an electronic circuit module having an improved mounting structure.

[0002]

2. Description of the Related Art In recent years, there has been an ever-increasing demand for smaller, thinner, more functional, and lower cost electronic devices and electronic devices. The study of miniaturization, thinning, high performance, and low cost of electronic circuit modules used in electronic devices is being rapidly promoted without exception.

A typical electronic circuit module includes a semiconductor element and electronic components mounted on a substrate to form an electronic circuit. The electronic circuit module also covers the electronic circuit to protect the electronic circuit and to shield the electronic circuit. There is an electronic circuit module having a metal case attached. In such an electronic circuit module, the number of circuit boards to be taken from one sheet substrate, which is an aggregate of circuit boards, is increased for the purpose of reducing the manufacturing cost and the number of steps by reducing the number of circuit boards. It is important to obtain as many circuit boards as possible in the circuit board manufacturing process.
In addition, the process of mounting semiconductor elements and chip-shaped electronic components on the substrate, the process of adjusting electrical characteristics, the casing process,
By carrying out the steps up to the final product step such as an electrical test step in the state of a sheet substrate, the transport time and the manufacturing time of the electronic circuit module are reduced.

[0004] Of these steps, a method of attaching a metal case on a substrate in a casing step is usually a method of attaching a metal case to a substrate.
There is a method in which a metal electrode for fixing the metal case is provided on the surface of the substrate, and the metal electrode and the metal case are fixed by soldering.

However, this method has a problem that the position of the metal case is shifted on the substrate after the metal case is soldered by a solder reflow furnace or the like, and the positional accuracy of the metal case cannot be ensured. Therefore, a metal case is provided with a bellows part, a hole for inserting and fixing this bellows part is formed at the end of the board, and the metal case is fixed by inserting the bellows part into the hole and fixing the position of the metal case. A technique of fixing the substrate to the substrate with high positional accuracy has been adopted.

Further, by forming a case-mounting end face electrode at an end of the board and soldering the case-mounting end face electrode and a bellows provided on the metal case, the adhesive strength between the metal case and the board is improved. There is also adopted a method of fixing and attaching.

Further, by using these fixing methods in combination, the metal case is fixed and attached to the substrate with high positional accuracy.

[0008]

However, in the conventional electronic circuit module in which the metal case is mounted as described above, all of the holes for inserting the bellows of the metal case into the ends of the board and the end face electrodes for mounting the case are provided. Since the area of the substrate becomes large because of the provision of the above, there is a problem that the size of the substrate cannot be reduced and it is not possible to meet the demand for miniaturization of the electronic circuit module.

Further, in the conventional electronic circuit module in which the metal case is attached as described above, in the casing process in the state of the sheet substrate, the adjacent metal cases and the bellows of the metal case become smaller as the substrate becomes smaller. When the metal case is soldered by a solder reflow oven etc., adjacent metal cases or bellows are soldered.As a result, the individual However, there has been a problem that the division into the electronic circuit module cannot be performed.

On the other hand, a method is adopted in which a multi-piece sheet board is divided before a casing process, and divided into individual circuit boards before mounting a metal case. However, there is a problem that the meaning of multi-cavity for the purpose of shortening the transport time and the manufacturing time cannot be utilized by manufacturing the sheet substrate to the final process.

Further, if the distance between adjacent metal cases on the sheet substrate is increased, a casing in the state of the sheet substrate can be realized, but in this case, the size of the substrate cannot be reduced, and the size of the electronic circuit module can be reduced. There was a problem that it could not be achieved.

The present invention has been devised to solve the above-mentioned problems, and an object of the present invention is to enable a metal case to be mounted on a substrate with good and accurate position without increasing the area of the substrate. Another object of the present invention is to provide an electronic circuit module that can sufficiently meet the demand for miniaturization.

[0013]

An electronic circuit module according to the present invention comprises a semiconductor element and electronic components mounted on a substrate to form an electronic circuit, and a metal case is attached so as to cover the electronic circuit. In the above electronic circuit module, the metal case is welded to a plurality of case mounting metal members provided on the substrate.

Further, in the electronic circuit module of the present invention, in the above configuration, the metal member for attaching the case is attached to a concave portion formed on the substrate.

Further, the electronic circuit module according to the present invention comprises:
In each of the above configurations, a hole smaller than a cross-sectional area of the metal member for attaching the case is formed in a welded portion of the metal case with the metal member for attaching the case.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electronic circuit module according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is an exploded perspective view showing an example of an electronic circuit module according to an embodiment of the present invention before a metal case is attached, FIG. 2 is a perspective view after the metal case is attached, and FIG. FIG. 3 is a partial sectional view taken along line AA ′.

FIG. 4 is a perspective view showing an example of a sheet substrate which is an aggregate of substrates when a large number of substrates of an electronic circuit module are simultaneously manufactured from one sheet substrate.

Each of the steps to be described below and the processing thereof, for example, a step of mounting a semiconductor element or an electronic component on a substrate, a step of adjusting electric characteristics, a casing step,
Until the final step, which becomes a product, such as an electrical test step, the transfer time and the manufacturing time of the electronic circuit module can be reduced by performing the processing in the state of a sheet substrate, which is an aggregate of bases as shown in FIG. By dividing the board after the casing is completed, the electronic circuit module of the present invention shown in FIGS. 1 to 3 can be obtained efficiently.

In these figures, 1 is a substrate, 2
Is a metal case. On a substrate 1, a semiconductor element 3 such as a semiconductor integrated circuit element and an electronic component 4 such as a chip capacitor and a chip resistor are mounted to form an electronic circuit. Reference numeral 5 denotes a plurality of case mounting metal members disposed on the substrate 1. The metal case 2 is welded to the top of the case mounting metal member 5 so that the metal case 2 is mounted on the substrate 1 by an electronic circuit. The electronic circuit module 6 of the present invention is configured so as to cover

The substrate 1 serves as both a base of the electronic circuit module 6 and a circuit board. For example, a multilayer ceramic circuit board or a glass epoxy board is used. Is preferably used.

The substrate 1 has a concave portion 1a on which the case mounting metal member 5 is mounted when the case mounting metal member 5 is mounted on the substrate 1, and a bellows portion 2a of the metal case 2.
It is preferable to form the bellows insertion recess 1b for performing the positioning in that the positioning accuracy can be further improved. In this manner, the metal member 5 for attaching the case 5 is
The case mounting metal member 5 can be disposed on the substrate 1 with high positional accuracy due to an alignment effect due to solder melting that occurs when the case mounting metal member 5 is soldered. .

Further, by providing the recess 1a for mounting the case mounting metal member 5, even when the case mounting metal member 5 is disposed adjacent to the case mounting metal member 5, the adjacent case mounting metal member 5 can be provided. This makes it easy to dispose the components close to each other so as not to be soldered.

According to the electronic circuit module 6 of the present invention,
Since the metal case 2 is attached to the substrate 1 by the metal member 5 for attaching the case, it is not necessary to form a metal electrode for fixing the metal case or an end surface electrode for attaching the case as in the conventional case. Even when the metal case 2 is positioned by the 2a and the groove insertion recess 1b, the area of the substrate 1 does not become large as in the related art.
Can be reduced in size.

Reference numeral 1c denotes a castellation on which mounting electrodes are formed when the electronic circuit module 6 is mounted on an external electric circuit board, and is provided as appropriate according to the specifications of the electronic circuit module 6.

Such a concave portion 1a and a concave portion 1 for inserting a bellows portion
b. To form the castellation 1c, for example, when the substrate 1 is a multilayer ceramic circuit board, a concave portion 1a is formed by punching a green sheet on the uppermost layer of the substrate 1 on which the semiconductor elements 3 and the electronic components 4 are mounted. A desired number of holes having a desired shape are formed, and a conductive wiring material is formed on the second layer green sheet corresponding to the bottom surface of the holes so that, for example, the metal member 5 for attaching the case can be soldered. These are laminated together with a green sheet on which another conductive wiring material is formed, and a recess 1b for inserting a bellows portion is formed.
And through-holes serving as castellations 1c are formed by working and then integrated by sintering to form recesses 1b for insertion of bellows.
-The board | substrate 1 which has the castellation 1c and in which the metal member 1 for case attachment can be soldered with high positional accuracy in the recessed part 1a provided on the board | substrate 1 can be obtained.

When such a substrate 1 is obtained from the sheet substrate 7 shown in FIG. 4, a green sheet in which a desired number of holes having a desired shape to be the concave portions 1a are formed as the uppermost green sheet is laminated. After forming a desired number of through holes 7b of a desired shape to become the slab insertion recesses 1b and a desired shape of through holes 7c to become the castellations 1c in the sheet substrate 7 thus separated, By performing sintering and integration, a sheet substrate 7 which is an aggregate of the substrates 1 is obtained. Then, the sheet substrate 7 is divided for each substrate 1 along the dotted line shown in the figure, whereby a concave portion 1a is formed on the upper surface, and a substrate having a concave portion 1b for insertion of a bellows portion and a castellation 1c on the side surface. 1 can be obtained. Reference numeral 7d denotes a positioning recognition mark provided on the ear of the sheet substrate 7.

The metal member 5 for attaching the case may be directly attached to a desired position on the substrate 1. In this case, the metal member 5 is attached with an adhesive or soldered to an attaching pad formed on the substrate 1. It should just be attached by.

The metal case 2 is mounted on the substrate 1 so as to cover the electronic circuit for protection of an electronic circuit formed on the substrate 1 and for electromagnetic shielding. As the material, iron, nickel silver, aluminum, SUS, copper, etc. are used.

The metal case 2 is provided with the positioning bellows 2a described above.
In order to reliably perform welding with the metal member 5, a hole 2 b smaller than the cross-sectional area of the metal member 5 may be formed at a position corresponding to the metal member 5. By forming the bellows portion 2a in this manner, the positioning accuracy of the metal case 2 can be further improved by positioning the bellows portion 2a by the recessed portion 1b for inserting a bellows portion. Further, by forming the holes 2b for welding with the case mounting metal member 5, the position of the case mounting metal member 5 can be confirmed, and the case mounting metal member 5 may be missing or spot welded. The welding state can be checked.

Further, the metal case 2 is subjected to a blackening treatment on its surface, particularly in the vicinity including the spot welded portion, so that the laser reflection is suppressed when the metal member 2 is welded to the case mounting metal member 5 by laser spot welding. This makes it possible to perform more efficient and favorable welding. As such a blackening treatment, for example, dark black plating such as black chrome may be applied.

The case mounting metal member 5 disposed on the substrate 1 is welded to the top of the metal case 2 so that the dead space on the substrate 1 is effectively used and the metal case 5 is attached to the substrate 1. By mounting the electronic circuit module 2, the size of the electronic circuit module 6 can be reduced. As long as the metal case 2 can be attached to the top of the head by welding, various shapes such as a polygonal pillar and the like in addition to a flat cylindrical top as shown in FIGS. Things can be used. In addition, the dimensions may be set so as to provide an appropriate space between the semiconductor element 3 or the electronic component 4 mounted on the surface of the substrate 1 and the metal case 2.

As the material of the metal member 5 for attaching the case,
Since the metal case 2 is usually formed of the above-mentioned metal material, the metal case 2 can be easily and reliably welded to such a metal. Alternatively, those subjected to a composite plating treatment or the like can be used.

A plurality of metal members 5 for mounting the case are provided on the substrate 1 in order to stably weld and mount the metal case 2, and the positions of the metal members 5 may be appropriately set according to the configuration of the electronic circuit. Good. In particular, as shown in FIG. 1, if the metal members 5 for attaching the case are arranged at three places on the substrate 1, the metal members 2 with a small number of the metal members 5 for attaching the case can be surely brought into contact with the metal case 2 and welded. This is preferable in that the metal case 2 can be stably attached to the substrate 1 so that a welding error when the metal case 2 is welded to the case mounting metal member 5 by laser spot welding or the like can be avoided. .

As a method for welding the metal case 2 to the metal member 5 for attaching the case, various welding methods can be used in addition to laser spot welding. -It is preferable in terms of productivity.

On the substrate 1, semiconductor elements 3 and electronic components 4
A wiring circuit, a solder pad, and the like for mounting the semiconductor device by soldering or the like are formed by printing or the like, and an electronic circuit is configured by mounting the semiconductor element 3 and the electronic component 4.

Here, the case mounting metal member 5 is mounted at a desired position by using a chip component mounting device, similarly to the semiconductor element 3 and the electronic component 4. In this way, by adopting a supply system that can support the case mounting metal member 5 with the component mounting apparatus in the same manner as the other semiconductor elements 3 and electronic components 4, it is possible to eliminate the conventional process of applying solder to these components. Become. Thereafter, the solder is melted using, for example, a solder reflow furnace to perform soldering, and the wiring, pads, recesses 1a, and the like on the substrate 1 are soldered to the semiconductor element 3, the electronic component 4, and the metal member 5 for attaching the case. I do.

Next, after a predetermined process such as characteristic adjustment is completed, the metal case 2 is mounted on each substrate 1 of the sheet substrate 7.

At this time, the bellows portion 2a of the metal case 2 is inserted into the through hole 7b of the sheet substrate 7 (the recess 1 for inserting the bellows portion of the substrate 1).
By inserting the metal case 2 in b), the metal case 2 can be mounted on the substrate 1 with high positional accuracy.

Next, the metal case 2 and the case mounting metal member 5 are spot-welded using a spot welding machine.

Here, as a spot positioning method at the time of spot welding, the metal case 2 and the case mounting metal member 5 are accurately welded by using the positioning recognition marks 7d provided at the ears of the sheet substrate 7. It is possible to do. In this way, by attaching the metal case 2 by spot welding without using solder as in the related art, the casing process in the state of the sheet substrate 7 becomes possible, and the manufacturing process can be simplified.

Then, after the casing, the sheet substrate 7 is divided for each substrate 1 to complete the electronic circuit module 6 of the present invention.

It should be noted that the present invention is not limited to the above example, and that various changes and improvements can be made without departing from the spirit of the present invention. For example, it goes without saying that a glass epoxy substrate may be used instead of the multilayer ceramic circuit substrate as the substrate material.

[0044]

According to the electronic circuit module of the present invention,
In a surface-mount type electronic circuit module in which a semiconductor element or a chip-shaped electronic component is mounted and an electronic circuit is configured, a metal case for protecting or electromagnetically shielding the semiconductor element or the electronic component mounted on the substrate is provided on the substrate. Since it is welded and attached to a plurality of case attaching metal members provided in the case, the metal case can be attached accurately without increasing the area of the board, and the metal case is attached to the end face of the board. By providing a recess for insertion and fixing of the velvet part, the positioning can be performed with high positional accuracy by the same method as in the past, and it is possible to meet the demand for miniaturization.

In addition, according to the electronic circuit module of the present invention, the case mounting metal member provided on the substrate is mounted in the concave portion formed on the substrate, so that the case mounting metal member is formed. Positional deviation can be completely avoided, and spot deviation during welding can be prevented.

Further, according to the electronic circuit module of the present invention, since a hole smaller than the cross-sectional area of the metal member for attaching the case is formed in the welded portion of the metal case with the metal member for attaching the case. The state of adhesion by welding to the mounting metal member can be easily confirmed from the surface of the metal case and also in the casing in the state of the sheet substrate, and can be inspected visually or by image recognition.

As described above, according to the present invention, a metal case can be mounted on a substrate with good precision and high positional accuracy without increasing the area of the substrate, and the electronic circuit can sufficiently meet the demand for miniaturization. Module could be provided.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an example of an embodiment of an electronic circuit module according to the present invention before a metal case is attached.

FIG. 2 is a perspective view showing an example of an embodiment of an electronic circuit module according to the present invention after a metal case is attached.

FIG. 3 is a partial sectional view taken along line AA ′ of FIG. 2;

FIG. 4 is a perspective view of a sheet substrate which is an aggregate of substrates of the electronic circuit module.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 1a ... Depression 2 ... Metal case 2b ... Hole 3 ... Semiconductor element 4 ... Electronic component 5 ... Metal member for case attachment 6 ... Electronic circuit module

Claims (3)

[Claims] 1. An electronic circuit module comprising: a semiconductor element and an electronic component mounted on a substrate to form an electronic circuit; and a metal case attached to cover the electronic circuit. An electronic circuit module, wherein the electronic circuit module is welded to a plurality of case mounting metal members provided on a substrate. 2. The electronic circuit module according to claim 1, wherein the metal member for attaching the case is attached to a concave portion formed on the substrate. 3. A hole formed in a welded portion of the metal case with the metal member for mounting the case, the hole being smaller than a cross-sectional area of the metal member for mounting the case. An electronic circuit module as described in the above.