JPH07202075A - Semiconductor module - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the number of manufacturing steps and miniaturize a semiconductor module in which unnecessary radiation is prevented. An electronic component 41a to 41d including a semiconductor element is mounted and wired on a wiring board 30 whose surface is covered with a conductor layer, and the wiring board 4 is cut out from the wiring board 30.
The semiconductor module 44 in which the wiring board 43 and the metal case are integrated is configured by bending 3 and forming a case that functions as a metal case that shields radiation of unnecessary radiation from the wiring board 43.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor module, and more particularly to improvement of a semiconductor module in consideration of reduction of unnecessary radiation.

[0002]

2. Description of the Related Art In recent years, electromagnetic waves emitted from electronic equipment such as information and communication equipment have been regulated to reduce unnecessary radiation so that other electronic equipment is not adversely affected.
I) is drawn. For this reason, various techniques have been researched and developed in order to reduce the level of unnecessary radiation to the regulation value or less.

For example, in the case of a semiconductor module for information communication equipment, the unnecessary radiation is reduced as follows.

11 and 12 are perspective views showing the structure of a conventional semiconductor module for information communication equipment.
Shows a state where the wiring board 82 is covered with a metal case 81 as a housing. FIG. 12 shows the wiring board 82 with the metal case 81.
The state before covering is shown.

Electronic components such as active electronic components 85a and passive electronic components 85b to 85f are mounted on the wiring board 82. The wiring board 82 has external connection terminals 83a to 83d.
It is adapted to be connected to another wiring board or the like via.

The metal case 81 is a blocking member for reducing unnecessary radiation of radio waves, and the metal case 81 is a holding portion 84 on a wiring board 82 on which electronic components 85a to 85f are mounted.
Soldered at a and 84b, they are mechanically held and electrically connected to the ground electrode surface.

According to the semiconductor module thus constructed, the electromagnetic waves radiated from the electronic components 85a to 85f and the wiring board are absorbed or attenuated by the metal case 81 and leak to the outside of the semiconductor module. It becomes possible to reduce electromagnetic waves.

However, the conventional semiconductor module has the following problems.

That is, as a result of requiring the metal case 81 separate from the wiring board 82 in order to reduce unnecessary radiation of radio waves, processing of the metal plate to be the metal case 81, metal case 8
The number of man-hours required for mounting 1 is increased, the price is increased, and a thick wiring board 82 must be used to secure the mechanical strength of the metal case 81, which makes it difficult to downsize the module. There was a problem.

[0010]

As described above, in order to reduce unnecessary radiation from the semiconductor module, a metal case separate from the wiring board is used as the housing, so that the number of manufacturing steps is increased and the module There are various problems such as difficulty in downsizing.

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a semiconductor module which can reduce unnecessary radiation, which is less problematic than conventional ones.

[0012]

To achieve the above object, the semiconductor module of the present invention is a semiconductor module in which a plurality of electronic components including semiconductor elements are mounted and wired on a wiring board. Is covered with a conductor layer, and the wiring board is bent to form a housing of the semiconductor module.

[0013]

According to the semiconductor module of the present invention, since the housing of the semiconductor module is formed by bending the wiring board covered with the conductor layer, the wiring board and the metal case are integrated. Unlike the conventional semiconductor module in which the wiring board and the metal case are separate from each other, there is no problem that the number of manufacturing steps is increased or the miniaturization of the module becomes difficult.

In other words, in the case of the present invention, the casing that plays the role of the metal case is formed from the wiring board, but the wiring board is generally thinner than the metal case, and after the wiring board is bent, solder or the like is used. It can be mechanically adhered without using, and a special adhesion step for attaching a metal case to a wiring board unlike the conventional case is eliminated, and the number of manufacturing steps can be reduced.

Further, as described above, since the casing that functions as the metal case is formed of the wiring board, in order to secure the mechanical strength of the metal case as in the conventional case,
Since it is not necessary to use a thick wiring board, the module can be downsized.

[0016]

Embodiments will be described below with reference to the drawings.

FIG. 1 is a perspective top view of a semiconductor module for information communication equipment according to a first embodiment of the present invention, FIG. 2 is a perspective bottom view of the same semiconductor module, and FIG. 3 is AA ′ of FIG. FIG.

The semiconductor module is roughly classified into a wiring board 11, external connection terminals 12a to 12f formed on the back surface of the wiring board 11, and electronic components 13a to 13a mounted on the main surface side of the wiring board 11. 13d and a resin 14 for molding these electronic components 13a to 13d. In this embodiment, the electronic component 13b is a semiconductor chip housed in a package.

The wiring board 11 is in the shape of a box, and the wiring board 11 is used as a housing and also serves as a conventional metal case for reducing unnecessary radiation.

That is, in the conventional case, the wiring board and the metal case were separate, but in the semiconductor module of the present embodiment, as will be described later, the wiring board is cut or bent. By assembling in a box shape, the wiring board and the metal case have an integrated structure.

The external connection terminals 12a to 12f are for establishing electrical connection between the semiconductor module and the outside. The electronic components 13a to 13d are mounted on the main surface of the wiring board 11 and covered with the mold resin 14 to be mechanically protected.

FIG. 4 is a sectional view showing a specific structure of the wiring board 11. In the figure, 21a and 21b indicate insulating substrates made of an insulating material such as aramid epoxy or polyimide.

Conductor layers 22a and 22b are provided on the insulating substrates 21a and 21b for mounting electronic components and for making electrical connection between the electronic components. These conductor layers 22a and 22b are formed of a metal material such as copper, nickel, or gold.

The conductor layer 22b is formed through the through holes 23a and 23c formed in the insulating substrate 21a.
Connected to. The conductor layer 22a is connected to the conductor layer 24 and the pad 25 via the through holes 23b and 23d. The front surface and the back surface of the wiring board 11 are covered with solder resist films 26a and 26b except for a region for making an electrical connection with the outside.

5 and 6 are process drawings showing the method for manufacturing the semiconductor module of this embodiment.

First, as shown in FIG. 5A, conductor layers 31a and 31b made of copper or the like are fixed to both surfaces of an insulating substrate 32 made of aramid epoxy or the like. Insulating substrate 32
The thickness is 60 μm for aramid epoxy, for example.
It is more than a degree. The conductor layers 31a and 31b have a thickness of about 10 to 80 μm.

That is, in this embodiment, the conductor layer 31b is thin in order to form a fine wiring layer on the main surface side of the insulating substrate 32, while the conductor layer 31a is formed on the back surface side in order to maintain mechanical strength. To be thick.

For example, when a large pattern of external connection terminals of about 300 to 500 μm is formed on the back surface, the conductor layer 31a may be as thick as about 80 μm.

Next, as shown in FIG. 5B, the conductor layer 31
An etching resist film (not shown) such as a dry film or a liquid resist is applied, cured and patterned on a and 31b to form a resist pattern, and then the conductor layer 31a
Are etched to form opening patterns 33a and 33b. After that, the etching resist film is removed.

The above etching is performed using a solution such as ammonium persulfate, and the etching resist film is removed using a solution such as acetone.

Further, the diameters of the opening patterns 33a and 33b are equal to those of through holes formed in a later process,
Usually, the thickness is equal to or more than the thickness of the insulating substrate 32.

Next, as shown in FIG. 5C, laser irradiation such as excimer laser is performed using the opening patterns 33a and 33b as masks to remove the insulating substrate 32 in the openings of the opening patterns 33a and 33b. , Through hole 34
a and 34b are formed.

Next, as shown in FIG. 5D, the conductor layers 35a, 3 are formed on the side walls of the through holes 34a, 34b, respectively.
5b is formed and the conductor layer 31a on the insulating substrate 32 is patterned to form a conductor pattern. The conductor layers 35a and 35b are formed by, for example, a method of using electroless copper plating and electrolytic copper plating in combination, which is used for manufacturing a multilayer substrate.

Next, as shown in FIG. 5E, an insulating layer 36 is formed on the entire surface and prepreg is performed, and then the insulating layer 36 is formed.
A conductor layer 31c laminated with a copper foil is formed on the top.
Generally, the thickness of the insulating layer 36 is about 60 μm or more, and
The conductor layer 31c has a thickness of about 10 to 80 μm.

Next, as shown in FIG. 5F, the insulating layer 36
A through hole 34c and a conductor layer 35c are formed on the substrate to form a conductor pattern. These forming methods are shown in FIG.
The method is similar to the method shown in (b) to (d).

Although the conductor layer formed on the main surface of the insulating substrate 32 is two layers, it may be formed of only one layer or three or more layers.

Next, as shown in FIG. 5G, the conductor layer 31
pattern c to form a conductor pattern, and
The conductor layer 31a is patterned to form external connection terminal patterns 37a and 37b on the back surface of the insulating substrate 32. Further, among the conductor layers 31a and 31c, patterns on which electronic components are mounted and external connection terminal patterns 37a and 37b are provided.
Solder resist films 38a and 38b are formed to cover surfaces other than the above. Here, the formation of the conductor pattern including the conductor layer 31c is performed by the same method as that shown in FIG.

The wiring board 30 formed by the above steps
A plan view of is shown in FIG. In the figure, reference numeral 40 denotes a wiring pattern, and FIG. 5G corresponds to a sectional view taken along the line BB ′ of FIG.

Next, as shown in the sixth (b), the electronic component 4
1a to 41d are mounted on the wiring board 30 by using solder or conductive resin. The figure shows a semiconductor chip housed in a surface mount package, but it is also possible to face-up mount or face-down mount a semiconductor chip that is not housed in the package, a so-called bare chip. is there.

Next, as shown in FIG. 6C, a mold resin 42 is applied and cured on the electronic component. Usually, an epoxy resin is used as the mold resin, but a silicone resin may be used.

Next, as shown in FIG. 6D, a wiring board 43, which is an actual module, is cut out from the wiring board 30 by using a die and a press. Normally, the wiring board 43 that becomes a module is smaller than the original wiring board 30, so that productivity can be improved by forming a plurality of wiring boards 43 on the same wiring board 30. It should be noted that one wiring board 43 out of the plurality of cut-outs is shown in the figure.

Finally, as shown in FIG. 6E, the semiconductor module 44 is completed by bending the wiring board 43 into a box shape.

Here, since the wiring substrate 43 is thin without using solder or the like, and the 72 is mechanically bonded, the bonding process such as soldering can be omitted and the number of processes can be reduced. Such mechanical adhesion is possible when the back surface of the wiring board 43 is made of Cu and the thickness thereof is 35 μm.

Thus, according to the present embodiment, the housing is formed by bending the wiring board covered with the conductor layer, and the wiring board and the metal case are integrated.
Unlike the conventional semiconductor module in which the wiring board and the metal case are separate from each other, there is no problem that the number of steps is increased and it is difficult to reduce the size of the module.

That is, in the case of the present embodiment, the housing (metal case) is formed from the wiring board, but the wiring board is generally thinner than the metal case, and after the wiring board is bent, solder or the like is used. It can be mechanically bonded without using it, and the special bonding process for mounting the wiring board to the metal case is eliminated as in the prior art, and the number of processes is reduced.

Further, since the housing (metal case) is formed of the wiring board, it is not necessary to use a thick wiring board in order to secure the mechanical strength of the metal case as in the conventional case. Can be miniaturized.

FIG. 7 is a sectional perspective view of a semiconductor module for information communication equipment according to a second embodiment of the present invention.

This embodiment is different from the previous embodiments in that, in addition to the bottom of the module, electronic parts 13e to 13h sealed with the molding resin 14a are provided on the top and wiring (not shown) is provided. It is also formed on the side surface of the wiring board 11. By adopting such a configuration, the packaging density can be further increased.

FIG. 8 is a perspective bottom view of a semiconductor module for information communication equipment according to a third embodiment of the present invention, FIG. 9 is a sectional view of the semiconductor module of FIG. 8 mounted on a motherboard, and FIG. 8 is a cross-sectional view of the wiring board of the semiconductor module of FIG.

This embodiment is different from the first and second embodiments in that, as shown in FIG. 8, an unnecessary radiation preventing electrode 55a is provided on the back surface of the semiconductor module so as to surround the external connection terminal 51. It is being done.

This electrode 55a is, as shown in FIG.
It is formed by patterning a conductor layer formed on a wiring board that will be the housing of the semiconductor module, and further patterning a solder resist film 61 covering the conductor layer into a frame shape. External connection terminals 51 are also formed at the same time by patterning the conductor layer. In the figure, 62 indicates an insulating substrate, and 63 and 64 indicate conductor layers.

As shown in FIG. 9, the semiconductor module 52 is connected to a mother board 53, and a ground electrode 54 on the mother board side and an electrode 55a for preventing unnecessary radiation on the semiconductor module side are connected by a grounding bump 55. ,
It is possible to reduce unnecessary radiation emitted from the external connection terminals 51 and the signal bumps 55 that connect the external connection terminals 51 and the motherboard 53.

In this embodiment, the electrode 50 for preventing unnecessary radiation is the frame-shaped electrode 50 without a break. However, if there is no problem in suppressing the unnecessary radiation, a broken electrode may be used. .

The present invention is not limited to the above embodiment. For example, although the semiconductor module for information communication equipment has been described in the above embodiments, the present invention can be applied to a semiconductor module for other electronic equipment.

In the above embodiment, the case where all the electronic components are covered with the molding resin has been described, but only some of the electronic components may be covered with the molding resin.

In addition, various modifications can be made without departing from the scope of the present invention.

[0057]

As described in detail above, according to the present invention, the number of manufacturing steps can be reduced by using a case formed by bending a wiring board covered with a conductor layer as a metal case, and reducing the number of manufacturing steps. It is possible to realize a semiconductor module excellent in prevention of radio wave interference while achieving miniaturization.

[Brief description of drawings]

FIG. 1 is a perspective top view of a semiconductor module for information communication equipment according to a first embodiment of the present invention.

FIG. 2 is a perspective bottom view of the same semiconductor module.

3 is a sectional perspective view taken along the line AA ′ of the semiconductor module of FIG.

FIG. 4 is a cross-sectional view showing a specific configuration of the wiring board 11.

FIG. 5 is a process drawing showing the manufacturing method of the first half of the semiconductor module of the first embodiment.

FIG. 6 is a process drawing showing the manufacturing method of the latter half of the semiconductor module of the first embodiment.

FIG. 7 is a sectional perspective view of a semiconductor module for information communication equipment according to a second embodiment of the present invention.

FIG. 8 is a perspective bottom view of a semiconductor module for information communication equipment according to a third embodiment of the present invention.

9 is a sectional view of the semiconductor module of FIG. 8 mounted on a motherboard.

10 is a cross-sectional view of the wiring board of the semiconductor module of FIG.

FIG. 11 is a perspective view showing a configuration of a conventional semiconductor module for information communication equipment.

FIG. 12 is a perspective view showing a configuration of a conventional semiconductor module for information communication equipment.

[Explanation of symbols]

 11 ... Wiring board 12a-12f ... External connection terminal 13a-13d ... Electronic component 14 ... Resin 21a, 21b ... Insulating board 22a, 22b ... Conductor layer 23a-23d ... Through hole 24 ... Conductor layer 25 ... Pad 26a, 26b ... Solder resist film 30 ... Wiring boards 31a to 31c ... Conductor layer 32 ... Insulating boards 33a, 33b ... Opening patterns 34a, 34b ... Through holes 35a, 35b ... Conductor layer 36 ... Insulating layer 37 ... External connection terminal patterns 38a, 38b ... Solder resist film 40 ... Wiring patterns 41a to 41d ... Electronic parts 42 ... Mold resin 43 ... Wiring board 44 ... Semiconductor module 50 ... Electrodes for preventing unnecessary radiation 51 ... External connection terminals 52 ... Semiconductor module 53 ... Motherboard 54 ... Ground electrode 55 ... Signal bump 61 ... Solder Regis Film 62 ... insulating substrate 63 ... conductive layer 64 ... conductive layer

Claims (1)

[Claims] 1. A semiconductor module in which a plurality of electronic components including semiconductor elements are mounted and wired on a wiring board, wherein the wiring board is covered with a conductor layer, and the wiring board is bent to form the semiconductor module. A semiconductor module having a case formed therein.