JPH05315778A - Electronic parts mounting board provided with heat sink - Google Patents

Abstract

PURPOSE:To provide an electronic parts mounting board, which has an enough heat-dissipating characteristic by making it into a heat sink and especially can achieve the fining of the surrounding of a device hole too, by using a simple structure. CONSTITUTION:For some of leads 11, through holes 16 or plating layers are formed in the surrounding of a device hole 13. Thereby, the electrical frettings, which serve for power supplying or grounding to the surface of the side of the device hole 13, are performed. Concurrently, other through holes 16, by which conductor circuits 15 provided on the surface of the side of the device hole 13 and the leads 11 are connected selectively, are exposed to the surrounding of the device hole 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component mounting board, and more particularly to an electronic component having a device hole for accommodating and mounting an electronic component and a heat sink accommodated and fixed in a heat sink hole communicating with the device hole. The present invention relates to a mounting board.

[0002]

2. Description of the Related Art In recent years, electronic parts (mainly so-called IC chips) have been highly densified, and the board on which they are mounted must be highly densified. In order to do so, the applicant has already proposed in JP-A-1-199497 and the like a technique for forming a substrate by integrating an insulating base material on both surfaces of a so-called lead frame composed of a large number of leads. By this technique, each lead can be selectively electrically connected to the conductor circuit on each insulating base material, and thus it is possible to provide a substrate corresponding to high density of electronic parts. ..

In addition, electronic components in recent years have been improved in performance along with the increase in density thereof, and accordingly, the amount of heat radiation is also increasing. This heat causes various problems such as deterioration of the performance of the electronic component when it accumulates in the vicinity of the electronic component. Therefore, a heat radiating member called a heat sink made of a metal plate or the like is also provided on the substrate. There is. In order to cope with the high performance of electronic components, it is also necessary to connect the conductor circuit of the substrate and the power source or ground terminal on the electronic component side as short as possible.

On the other hand, the electronic components become smaller as the density becomes higher, and the heat sink for radiating heat becomes larger, and moreover, the electronic components and the heat sink should be in direct contact with each other. Good heat conduction.
Furthermore, when wire bonding to the mounted electronic components, the height of the electrodes on the electronic components and the height of the electrodes on the substrate can be matched to facilitate the bonding work and improve the connection reliability. The device hole and the heat sink hole for accommodating the heat sink have to have the relationship shown in FIG. In other words, the part of the substrate that forms the device hole floats above the heat sink hole and becomes an unstable state. Conductor circuits, through holes, etc. It is difficult to form directly.

Therefore, it has become necessary to satisfy various conditions for a substrate for mounting electronic components, which have been made higher in density and higher in performance, and the conditions are becoming more complicated. Is what In particular, it is an absolute requirement to make the conductor circuit on the board side, mainly around the device hole, an absolute requirement. While trying to achieve heat dissipation characteristics and electrical connection reliability while achieving this fining, It is necessary to specify the structure of the side more specifically.

[0006] Therefore, the inventors of the present invention, as a substrate for mounting electronic components which have been made higher in density and higher in performance, satisfy various conditions and are mainly used for a conductor circuit or the like around the device hole. The present invention has been completed as a result of various studies on how to perform finer processing.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and the problem to be solved is further refinement of an electronic component mounting substrate having a heat sink.

An object of the present invention is to provide a substrate for mounting electronic parts with a simple structure, which has a sufficient heat dissipation characteristic by using a heat sink and can achieve fineness especially around the device hole. To do.

[0009]

Means for Solving the Problems To solve the above problems, the means adopted by the present invention will be described with reference to the reference numerals used in the examples. 12 are integrated to electrically connect the conductor circuit 15 on the insulating base material 12 to any of the leads 11, and the device hole 13 in which the electronic component 30 is housed.
An electronic component mounting board 10 comprising: a heat sink hole 14 communicating with the heat sink hole 14 to expose an end portion of the lead 11; and a heat sink 20 housed and fixed in the heat sink hole 14, which is a part of the lead. 11 is electrically routed to the surface of the device hole 13 for power or ground by the through hole 16 or the plating layer 17 formed around the device hole 13, and the conductor circuit 15 of the surface of the device hole 13 side is provided. And a through hole 16 that is selectively connected to the lead 11 is exposed around the device hole 13 ".

[0010]

The operation of the electronic component mounting board 10 according to the present invention constructed as above will be described in detail below.
First, in the electronic component mounting board 10, as shown in FIG. 1 or 2, a part of each lead 11 is exposed in the heat sink hole 14 formed in the insulating base material 12. Some of the leads 11 are electrically connected to the conductor circuit 15 and the like formed on the upper surface side in the drawing by the through holes 16 or the plated layer 17. Therefore, the heat sink 20 stored in the heat sink hole 14 and connected to the lead 11 side
Can be used as a power source or a ground even if it is positioned below the device hole 13 in the drawing, and can directly mount the electronic component 30 housed in the device hole 13 on the upper surface of the drawing. It has become.

Further, a conductor circuit 15 is provided around the device hole 13 on the upper side of the heat sink hole 14 in the figure.
Since the end portion of the device and the through hole 16 are positioned and exposed, the electronic component 30 housed and mounted in the device hole 13 is located at a very close distance to the conductor circuit 15 and the through hole 16. Will be done. Furthermore, by adjusting the depth of the device hole 13 according to the thickness of various electronic components 30, it becomes an optimal position for the bonding wire. Therefore, the electrical connection between the electronic component 30 mounted on the upper surface of the heat sink 20 exposed in the device hole 13 and the conductor circuit 15 or the through hole 16 on the electronic component mounting substrate 10 by a bonding wire or the like is extremely high. Not only is it easy, but the length of the bonding wires and the like is extremely short, so that the electronic component mounting substrate 10 can have a so-called high shielding effect. When the mounted electronic components 30, bonding wires, etc. are sealed with resin, the sealing portion of the electronic component mounting substrate 10 is very small, and the sealing work can be facilitated. It goes without saying that it is something to do.

Further, in this electronic component mounting substrate 10, as shown in FIG. 1 or 2, the device hole 1
The insulating base material 12 forming part 3 is located on the heat sink hole 14, and the through hole 16 and the end portion of the conductor circuit 15 are arranged on the part of the insulating base material 12. There is. In addition, each through hole 16 is an insulating base material 1.
Electrical connection is selectively made to each of the leads 11 in the wiring 2. Therefore, on the insulating base material 12 located around the device hole 13, the fineness that can sufficiently correspond to the highly densified electronic component 30 is achieved.

[0013]

EXAMPLE Next, the electronic component mounting substrate 10 according to the present invention
Referring to the embodiment shown in the drawings, FIGS. 1 and 2 show partially enlarged perspective views of the electronic component mounting board 10. The electronic component mounting board 10 shown in FIG. 1 and that of FIG. 2 differ from each other in the means for electrically routing the upper surface side of the figure and the necessary lead 11 side when the heat sink 20 is used as a power source or a ground. The plated layer 1 formed by the through hole 16 in FIG. 1 and in the device hole 13 in FIG.
It is done by 7. Since the other configurations of both electronic component mounting boards 10 are substantially the same, FIG.
The members common to the electronic component mounting board 10 shown in FIG. 2 are denoted by the same reference numerals in FIG. 2 to omit the specific configuration description of the electronic component mounting board 10 shown in FIG. To do.

The electronic component mounting substrate 10 shown in FIG.
A lead frame composed of a large number of leads 11 is centered, and insulating base materials 12 are integrated on both surfaces thereof.
A predetermined conductor circuit 15 is provided on the front surface side of both insulating base materials 12.
Is formed. In addition, in the electronic component mounting board 10, a device hole 13 in which the electronic component 30 is to be accommodated later is formed in a predetermined portion on the upper side, and the device hole 13 allows the end of each lead 11 to be formed as needed. It is also possible to make each part independent. .. A heat sink hole 14 having an opening area larger than that of the device hole 13 is formed on the lower side of the device hole 13 in the figure, and the lower surface of the inner end portion of each lead 11 is formed in the heat sink hole 14 by the heat sink hole 14. It is exposed to. The device hole 13 and the heat sink hole 14 are formed by a process of moving a rotating drill in the lateral direction, so-called spot facing.

A through hole 16 penetrating the insulating base material 12 protruding above the heat sink hole 14 is formed for a selected one of the leads 11, and the through hole 16 is formed. The upper portion in the figure is exposed on the upper insulating substrate 12. The upper end of the through hole 16 also serves as a pad for electrically connecting to the electronic component 30 housed in the device hole 13. In the electronic component mounting substrate 10 shown in FIG. 2, as an alternative to the through hole 16, a continuous plating layer 17 is formed in the device hole 13 which is partially on the insulating base material 12 on the upper side in the drawing. There is one. The end of the conductor circuit 15 is arranged on the upper surface of the insulating base material 12 projecting above the heat sink hole 14 in the figure.

Since the conductor circuit 15 and the through hole 16 as described above have to be formed on the insulating base material 12 which protrudes above the heat sink hole 14 in a so-called unstable state, in the present embodiment, It is formed by the following method different from the above method.

Substrate 10 for mounting electronic components in this embodiment
Before describing the manufacturing method of FIG. 4, a conventional manufacturing method for comparison will be described. In this conventional manufacturing method, as shown in FIG. 13 (upper side in the figure) and heat sink hole 14
(The lower side in the drawing) is formed by spot facing, and a plating layer to be a conductor circuit or the like is formed on the entire surface as shown in FIG. 4B. After that, a material to be an etching resist such as a photo solder resist was formed on the side surface of the device hole 13 of the insulating base material 12, and then a predetermined conductor circuit or the like was formed. However, in this conventional method, the photo solder resist or the like has to be integrated by pressure bonding also on a part of the insulating base material 12 protruding in an unstable state on the heat sink hole 14, and therefore the insulating base material is required. As shown in FIG. 4 (c), the portion of the protruding portion 12 of the heat sink hole 12 is easily bent by the pressing force. Insulating substrate 1
If 2 is bent, the photo solder resist or the like, which must be adhered onto it, cannot be adhered to the insulating base material 12 completely, so that patterning for forming a conductor circuit cannot be performed accurately. It will end up. In order to avoid this, it is necessary not to form a conductor circuit on the insulating base material 12 projecting above the heat sink hole 14, and if this happens, fineness around the device hole 13 cannot be expected at all. Of.

In this respect, in the manufacturing method of this embodiment,
As shown in (a) of FIG. 3, first, the device holes 13
A hole for the through hole 16 is formed in the portion immediately adjacent to, and as shown in FIG. 3B, a metal plating layer is formed on the entire insulating base material 12 also for so-called through hole plating. To do. Then, in this state, using a photo solder resist or the like, as shown in FIG. 3C, lands of predetermined conductor circuits 15 and through holes 16 are formed on the surface of each insulating base material 12. Of. In this case, since there is no part that becomes unstable during the working operation, the lands of the conductor circuits 15 and the through holes 16 are formed in a fine state.

After that, as shown in FIG. 3D, a device hole 13 for housing the electronic component 30 and a heat sink hole 14 for the heat sink 20 are formed by spot facing. In this case, the device hole 13
Is formed in a state as close to the conductor circuit 15 and the through hole 16 as possible, and it is possible that the counterboring process therefor does not adversely affect other portions. In this case, of course, in the spot facing process for forming the heat sink hole 14, it is necessary to expose the inner end of each lead 11 to the inside of the heat sink hole 14, so that FIG. As shown in FIG. 3, the tip of the tool for spot facing is controlled so as to be positioned substantially at the center of each lead 11. In order to obtain the electronic component mounting substrate 10 shown in FIG. 2, the device hole 13 may be formed in place of the through hole 16.

The electronic component mounting board 10 is completed by housing the heat sink 20 in the heat sink hole 14 and fixing the heat sink 20 to the one formed as described above.

[0021]

As described above in detail, in the present invention,
As illustrated in the above-described embodiment, "the insulating base material 12 is integrated on the front and back of a large number of leads 11, and the conductor circuit 15 on the insulating base material 12 and any one of the leads 11 are electrically connected. , A device hole 1 for housing the electronic component 30
An electronic component mounting substrate 10 comprising: 3, a heat sink hole 14 communicating with the heat sink hole 14 to expose an end portion of the lead 11, and a heat sink 20 housed and fixed in the heat sink hole 14. The lead 11 is electrically routed to the surface of the device hole 13 for power or ground by the through hole 16 or the plating layer 17 formed around the device hole 13, and the conductor circuit of the surface of the device hole 13 side is also provided. 15 and the through hole 16 for selectively connecting to the lead 11 are exposed around the device hole 13. "This is a characteristic of the structure, which makes it possible to have a sufficient heat dissipation characteristic by forming a heat sink, and in particular, a device. It is possible to provide a substrate for mounting electronic components that can achieve finer areas around the holes with a simple structure. It's that.

[Brief description of drawings]

FIG. 1 is a partially enlarged perspective view of an electronic component mounting board according to the present invention.

FIG. 2 is a partially enlarged perspective view showing another embodiment of the electronic component mounting board.

FIG. 3 is a partial enlarged cross-sectional view showing the method of manufacturing the electronic component mounting board in the order of steps.

FIG. 4 is a partial enlarged cross-sectional view showing, in the order of steps, a method for manufacturing a conventional electronic component mounting board.

[Explanation of symbols]

 10 Electronic Component Mounting Board 11 Lead 12 Insulating Base Material 13 Device Hole 14 Heat Sink Hole 15 Conductor Circuit 16 Through Hole 17 Plating Layer 20 Heat Sink 30 Electronic Component

Claims (1)

[Claims] 1. A device hole in which an insulating base material is integrated on the front and back surfaces of a large number of leads to electrically connect a conductor circuit on the insulating base material to any one of the leads, and in which electronic parts are accommodated. And a heat sink hole communicating with this and exposing the ends of the leads, and a heat sink housed and fixed in the heat sink hole, which is an electronic component mounting substrate, wherein for some of the leads, A through hole or a plating layer formed around the device hole provides electrical routing for the power or ground to the device hole side surface, and selectively connects to the conductor circuit and the lead on the device hole side surface. A substrate for mounting an electronic component, wherein a through hole to be exposed is exposed around the device hole.