JP2881264B2 - Electronic component mounting board with mounting recess - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate for mounting electronic components, and more particularly to an electronic component mounting substrate in which electronic components are housed and mounted in mounting recesses provided in an insulating base material. Things.

[0002]

2. Description of the Related Art Various types of substrates for mounting electronic components have been proposed up to now, but the applicant has been able to cope with the high density of electronic components and can easily manufacture them. An electronic component in which an insulating base material is integrated on both sides of the lead and inside each outer lead part, and a conductor circuit on the insulating base material and each lead are electrically connected by through holes. Mounting substrates have already been proposed. As shown in FIG. 1 and the like, the electronic component mounting board is sealed with a sealing resin with the outer leads protruding together with the electronic components mounted thereon to form an electronic component mounting apparatus. Things.

On the other hand, various types of electronic components to be mounted on such electronic component mounting boards have been proposed, and the overall shape has been increased with the increase in capacity and the like. If such a large-sized electronic component is mounted and sealed with a resin, the thickness of the entire device becomes large, and it is no longer possible to satisfy the recent demand for lighter, thinner and smaller devices.

[0004] For this reason, as shown in FIG. 4, it is conceivable to form a mounting recess in an insulating base material and house and mount electronic components therein. However, simply forming the mounting recesses as described above is not effectively used as a space for forming a conductor circuit whose area is becoming more and more complicated. As shown in FIG. 6, it has been considered to form a metal layer that can be electrically connected to an electronic component in the mounting recess. This metal layer is usually formed using a plating technique, but it is difficult to form this metal layer as a plurality of independent members in the mounting recess. In other words, depending on such a metal layer, as shown in FIGS. 5 to 7, it can be formed as a so-called simple terminal such as a power supply terminal or a ground terminal of an electronic component. It is very difficult to form a plurality of terminals for electronic components.

[0005] In particular, in general, electronic components are generally electrically connected to a conductor circuit on a substrate using a so-called bonding wire.
In recent years, a large number of devices that are directly mounted on connection terminals without using such bonding wires, that is, surface mounting devices, have been provided. Such electronic components naturally require connection terminals exposed on the same plane. Therefore, if the metal layer in the mounting recess is a single metal layer as shown in FIGS. 5 to 7, such a surface-mounted type electronic component cannot be mounted in the mounting recess. It is.

Accordingly, the present inventors have formed a plurality of connection terminals effectively on the bottom surface of the mounting recess, which can accommodate electronic components and reduce the overall thickness, similarly to the case of the insulating base material. The present invention has been completed as a result of various studies on how to use it as a part to perform.

[0007]

SUMMARY OF THE INVENTION The present invention has been made based on the above circumstances, and the problem to be solved is to make effective use of the mounting recess.

An object of the present invention is to provide a mounting concave portion which can reduce the total thickness when the electronic component is housed and completed as a device. Connection terminals can be formed for
It is an object of the present invention to provide an electronic component mounting substrate capable of effectively and sufficiently making electrical connection of electronic components within the mounting recess.

[0009]

In order to solve the above-mentioned problems, the means adopted by the present invention will be described with reference numerals used in the embodiments. The insulating base material 13 is integrated on both sides of the large number of leads 12 and inside the outer lead portion 12a of each lead 12, and the conductor circuit 14 on the insulating base material 13 and each lead 12 are passed through. The electronic component mounting substrate 1 which is made conductive by the holes 16 and is entirely sealed together with the mounted electronic components 20.
0, on one surface of the electronic component mounting substrate 10, mounting recesses 15 having different depths for accommodating and mounting the electronic components 20 are formed, and among these mounting recesses 15, Lead 1 on at least one bottom
The mounting recesses 1 are characterized in that a plurality of the end portions 2 are exposed, and these ends are used as connection terminals 17 for the electronic components 20 housed in the mounting recesses 15.
5 ".

[0010]

In the electronic component mounting board 10 according to the present invention having the above-described structure, the mounting recess 15 for accommodating the electronic component 20 is formed. Naturally, when the electronic component 20 having a certain thickness is mounted on an electronic component mounting apparatus, the thickness of the electronic component 20 is absorbed by the mounting recess 15. As a result, the thickness of the entire apparatus can be reduced. In particular, each mounting recess 15 is
Since a plurality of electronic components 20 having different heights are mounted, when the plurality of electronic components 20 having different heights are mounted, the protruding outer surface (the upper surface in FIG. 1) is substantially uniform. It is possible.

In the electronic component mounting board 10 shown in FIGS. 1 and 3, the power supply terminal or the ground terminal is provided in the mounting recess 15 having a smaller depth than the other mounting recesses 15. A metal layer to be formed is formed, and an external connection terminal of the electronic component 20 mounted on the metal layer and the conductor circuit 14 on the insulating base 13 are connected by a bonding wire. In other words, although the prior art is employed in the mounting recess 15 having the smaller depth, the mounting recess 1 having the larger depth is used.
5, the present invention is applied.

As shown in FIG. 1 or FIG. 3, a plurality of connection terminals 17 are exposed on the bottom surface of the mounting recess 15 whose depth is larger than the others. These connection terminals 17 are obtained by exposing portions of the respective leads 12 sandwiched between the respective insulating bases 13 opposite to the outer lead portions 12a into the mounting recesses 15 by the insulating bases 13 and the like. The components are located on the same plane so that surface mounting of the electronic component 20 can be performed. Since these connection terminals 17 are originally formed using the leads 12 which are electrically independent from each other, it is needless to say that each of the connection terminals 17 formed on the lower side of the electronic component 20 in the drawing is used. It can be connected to the power supply independently.

In other words, in the electronic component mounting board 10 according to the present invention, the plurality of connection terminals 17 are exposed on at least one bottom surface of the mounting recess 15. The connection terminals of the electronic component 20 can be directly and electrically connected to the connection terminals 17. Moreover, the mounting recess 1 exposing the plurality of connection terminals 17 is provided.
5, the electronic component 20 having a large thickness can be mounted while absorbing most of the thickness.
As described above.

[0014]

Next, an electronic component mounting substrate 10 according to the present invention will be described.
Will be described in detail according to Embodiments 1 and 2 shown in the drawings.

(Embodiment 1) FIGS. 1 and 2 show an electronic component mounting board 10 according to Embodiment 1 of the present invention.
In the electronic component mounting board 10, two lead frames 11 are integrated by sandwiching them between three insulating base materials 13. That is, in this embodiment, as shown in FIG. 1, the lead frame 11 located on the upper side in the figure has a plurality of leads 12 having the outer lead portions 12a, Each lead 12 of the lead frame 11 is an insulating base material 1
It is a thing which did not go outside from 3. A predetermined conductor circuit 1 is provided on the surface of the insulating base material 13 located outside.
The conductor circuit 14 and the lead 12 of each lead frame 11 are selectively electrically connected to each other by a through hole 16 passing therethrough.

Of course, the lead frame 1 shown in FIG.
As shown schematically in FIG. 2, a plurality of leads 12 to be electrically independent are integrated by a tie bar which is cut off until the product is completed. The portion outside the insulating base material 12 is an outer lead portion 12a for making an electrical connection to another portion. In this embodiment, each lead frame 11 is formed using a metal plate having a thickness of 0.15 or 0.25 mm.

As shown in FIG. 1, the electronic component mounting board 10 has two mounting recesses 15 having different depths formed by so-called counterboring processing of the insulating base material 13 and the like from the upper side in the figure. The mounting recess 15 on the left side in the figure is deeper than that on the right side in the figure. The bottom surface of the deep mounting recess 15 reaches the lower lead frame 11, while the bottom surface of the shallow mounting recess 15 reaches only the upper lead frame 11. is there. In addition, on the inner surface of the shallow mounting recess 15, a metal layer formed by plating, for example, and electrically connected to some of the leads 12 is formed. The terminal 15 serves as a power terminal or a ground terminal for the electronic component 20 housed in the housing 15.

On the bottom surface of the deep mounting recess 15, a plurality of leads 1 constituting the lower lead frame 11 are formed by counterboring.
The inner end side of 2 is exposed, whereby a plurality of connection terminals 17 electrically independent from each other are formed. Generally, the depth accuracy of so-called spot facing is 0.1 mm.
Each lead frame 11 in this embodiment has a thickness of 0.15 mm or 0.25 mm.
Since a metal plate formed by using a metal plate of mm is adopted, it can sufficiently fit within this spot facing precision. Rather, if the deeper mounting concave portion 15 has a depth such that the inner end of the lead 12 constituting the lower lead frame 11 is slightly removed, the insulating portion can be insulated within the processing accuracy range described above. Connection terminal 17 with no attachment of objects
Can be formed.

With respect to the electronic component mounting board 10 according to the first embodiment configured as described above, as shown in FIGS. In addition, the entire insulating base 13 including these electronic components 20 is sealed with the sealing resin 30 so that the outer lead portions 12 are provided outside the sealing resin 30.
This makes it possible to form an electronic component mounting device in which a protrudes. In this case, since the connection terminals 17 are exposed at the bottom of the mounting recess 15 on the deeper side, the electronic component 20 can be surface-mounted by using these connection terminals 17. In addition, each electronic component 2
Since 0 is stored in the mounting recess 15 and mounted, it is natural that the overall thickness of the electronic component mounting apparatus can be reduced.

The electronic component mounting board 10 according to the first embodiment has the following effects in addition to the effects inherent in the present invention. That is, since the electronic component mounting board 10 is formed by integrating two lead frames 11 and three insulating base materials 13 sandwiching them, the board 10 has high rigidity as a whole, As a result, the electronic component mounting substrate 10 does not cause problems such as warpage and bending. Also,
Since two lead frames 11 are used, one side is used for a power source and the other side is used for a ground, so that the electrical stability of the device can be easily secured. It has become something.

(Embodiment 2) FIG. 3 shows a second embodiment of the electronic component mounting board 10 according to the present invention. First, the electronic component mounting substrate 10 in the second embodiment uses only one lead frame 11, and second, it should be the bottom surface of the deep mounting recess 15. That is, each lead 12 located at that portion is bent downward in the figure.

That is, the electronic component mounting board 10 has two mounting recesses 15, and both the mounting recesses 15 have the leads 12 exposed on the bottom surfaces thereof. The mounting recess 15 located on the left side in FIG. 3 is formed by counterboring until the lead 12 bent downward in the figure at the bending portion 18 is exposed. Therefore, the depth of the mounting recess 15 on the left side is larger than that of the mounting recess 15 on the right side in the figure. Such a bent portion 18 may be formed in advance by pressing a predetermined portion of each lead 12 after forming the lead frame 11. What is necessary is just to integrate each insulating base material 13 with the lead frame 11 thus obtained.

Electronic component mounting board 1 according to the second embodiment
A value of 0 has the advantage that it can be manufactured at low cost, in addition to the effects inherent in the present invention.

[0024]

As described in detail above, in the present invention,
As exemplified in each of the above embodiments, the “lead frame 11
The insulating base material 13 is integrated on both sides of the multiple leads 12 integrated with the inner lead portion 12a of each lead 12 and the conductor circuit 14 on the insulating base material 13 And the leads 12 are electrically connected to each other through the through holes 16 so as to seal the whole together with the plurality of mounted electronic components 20. A plurality of mounting recesses 15 having different depths for accommodating and mounting the electronic components 20 are formed, and a plurality of end portions of the leads 12 are exposed on at least one bottom surface of the mounting recesses 15. The electronic components 20 accommodated in the mounting concave portion 15
For the connection terminal 17 ".
Thereby, when the electronic component is housed and completed as a device, it has a mounting recess capable of reducing the overall thickness, and a connection terminal for the electronic component can be formed therein. In addition, it is possible to provide an electronic component mounting substrate capable of effectively and sufficiently making an electrical connection between the electronic components in the mounting concave portion.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an electronic component mounting apparatus configured by mounting electronic components on an electronic component mounting board according to Embodiment 1 of the present invention.

FIG. 2 is a plan view showing a state before each lead of the electronic component mounting apparatus shown in FIG. 1 is made independent.

FIG. 3 is a cross-sectional view of an electronic component mounting apparatus configured using an electronic component mounting board according to a second embodiment of the present invention.

FIG. 4 is a partial cross-sectional view of a conventional substrate subjected to spot facing.

FIG. 5 is a partial cross-sectional view of a conventional substrate in which a metal layer is formed in a counterbored recess.

FIG. 6 is a plan view of the substrate shown in FIG.

FIG. 7 is a cross-sectional view of an electronic component mounting apparatus configured using a conventional substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Electronic component mounting board 11 Lead frame 12 Lead 12a Outer lead part 13 Insulating base material 14 Conductive circuit 15 Mounting concave part 16 Through hole 17 Connection terminal 18 Bent part 20 Electronic component 30 Sealing resin

Claims (1)

(57) [Claims] An insulating base is integrated on both sides of a large number of leads integrated by forming a lead frame and inside each outer lead portion of each lead, and a conductor on the insulating base is provided. In an electronic component mounting board in which a circuit is electrically connected to each of the leads through through holes and the whole is sealed together with a plurality of mounted electronic components, one surface of the electronic component mounting board includes By forming mounting recesses having different depths for storing and mounting electronic components, and exposing a plurality of ends of the leads to at least one bottom surface of these mounting recesses, An electronic component mounting substrate having a mounting recess, wherein an end of the electronic component mounting terminal is a connection terminal for an electronic component housed in the mounting recess.