JPH0745928A - Composite electronic part - Google Patents

Abstract

PURPOSE:To omit wiring in multiple layers for a wiring board by arranging at least one electronic part on each of both surfaces of the wiring board so as to face each other and so as to hold the wiring board at the upper surface and the rear surface of at the rear surface and the upper surface of the respective electronic parts. CONSTITUTION:An IC 2 is provided so that a surface 2 faces upward. An electrode, which is formed on an upper surface 2' is connected to an upper surface 1' of a wiring board 1 with a wiring 4 on the wiring board 1 by a wire bonding method. A surface 3' of an IC 3 is made to face a lower surface 1'' of the wiring board 1. The electrode, which is formed on the surface 3', is made to face the connecting part of a wiring 6 on the wiring board 1 through an anisotropic conductive resin 7 and connected to the connecting part. The wiring 6 on the side of the upper surface 1' of the wiring board 1 is connected to the wiring 7 on the side of the lower surface 1' of the wiring board 1 by passing the wiring by way of a through hole 8 provided in the wiring substrate 1. Thus, it is not necessary to form complicated wiring patterns.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite electronic component in which a plurality of electronic components such as a hybrid IC such as a memory module and a mirror circuit are mounted on both sides of a wiring board.

[0002]

2. Description of the Related Art In composite electronic parts such as hybrid ICs, there is a method of mounting electronic parts on both sides of a wiring board as a method for further improving the degree of integration and reducing the size. Conventionally, in this method, for example, when bare chip ICs as the above-mentioned electronic parts are arranged facing both sides of a wiring board, the upper surface and the lower surface of the wiring board 21 may be arranged as shown in the schematic sectional view of the mounting structure in FIG. First, the bare chip ICs 22 and 23 have surface (electrode forming surface) 22 ',
23 ′ is on the upper side of the wiring board 21, in other words, the bare chip ICs 2 on both surfaces of the wiring board 21.
Wire bonding is performed between the electrodes formed on the front surfaces 22 ′ and 23 ′ of the bare chip ICs 22 and 23 and the wirings of the wiring board 21, which are mounted so as to sandwich the wiring board 21 between the back surfaces 22 ″ and 23 ″ of the wiring boards 2 and 23. It was structured to connect by the method.

Further, in the above method, for example, when the mold package ICs are mounted on both sides of the wiring board, as shown in FIG.
As shown in FIG. 1, the mold package ICs 25 and 26 on both surfaces of the wiring board 21 are mounted such that their surfaces (element forming surface side) 25 ′ and 26 ′ are on the upper side of the wiring board 21 and are molded. Package IC2
The outer leads 27 of 5, 26 are connected to the wiring of the wiring board 21 by soldering or the like.

[0004]

However, when the electronic components are arranged facing each other on both sides of the wiring board by the conventional method as described above, the electronic components arranged facing each other are, for example, the same or similar. , When the electrodes of the power supply terminal, the ground terminal, the input terminal, the output terminal, etc. are arranged to be the same or similar, the electrodes of the electronic component are connected to each other by using wiring or are commonly led out, Alternatively, since it is necessary to draw out the wirings closely so that any of the electrodes can be connected to a single external lead-out terminal, the wirings are long on both sides of the wiring board and become a very complicated pattern.

That is, as shown in FIGS. 12 and 13, for example, bare chip ICs 2 of the same kind are formed on both surfaces of the wiring board 21.
To describe the case where 2,23 to face arranged to connect the wiring electrodes a ₁ and interconnect the common electrode together with the bare chip IC22 Fu such electrodes a ₁ of the bare chip IC23 and 23 and the substrate 21 of the bare chip IC22, allogeneic When the bare chips ICA1 and A2 are arranged on both surfaces of the wiring board 21 so that the bare chips ICA1 and A2 face the wiring board 21 with the electrode forming surface facing upward, the bare chips ICA1 and A2
Since the positions of the electrodes a ₁ , a ₂ , a ₃ , and a ₄ of FIG. ₂ are reversed to the opposite side, the common electrode cannot be connected on both sides of the wiring board 21 unless the wiring for connection is extended to the opposite side. For this reason, the wiring must be a long and complicated pattern on both sides of the wiring board 21. Therefore, the area occupied by the wiring becomes large, which is a cause of hindering high integration.

Therefore, in order to solve the problem of the area of the wiring, a method of forming the wiring substrate 21 in a multilayer structure and passing the wiring between the layers is also performed, but the wiring becomes complicated, too.
Separate equipment is required to manufacture such a wiring board, resulting in an increase in the number of steps and a high cost. Further, there is also a problem that reliability decreases due to noise such as crosstalk due to mutual interference between wirings due to the wirings crossing or approaching each other.

Furthermore, since the wiring becomes long as described above,
It is also an obstacle to speeding up.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a composite electronic component which is highly reliable and can be integrated and speeded up.

[0009]

As a result of intensive studies to achieve the above object, the present inventor has found that when a plurality of electronic components are mounted on both sides of a wiring board, an electronic device having electrodes that can share wiring is used. It has been found that the wiring can be minimized when the parts are arranged so as to have the same direction in a sectional view through the wiring board.

That is, the present invention relates to the following composite electronic component.

In a composite electronic component in which a plurality of electronic components having the element formation surface as the surface are mounted on both sides of a wiring board, at least one electronic component on each side of the wiring board is A composite electronic component having a structure in which a front surface and a back surface or a back surface and a front surface are arranged so as to face each other so as to sandwich the wiring substrate.

[0012] The composite electronic component as described above, wherein the electronic components arranged opposite to the wiring board have the same or similar electrode arrays for input terminals or output terminals.

The composite electronic component as described above, wherein the electronic components arranged opposite to the wiring board have the same or similar electrode arrays for power terminals or ground terminals.

The composite electronic component according to any one of the above 1 to 3, wherein one or both of the electronic components arranged facing the wiring board are bare chip components.

The wiring formed on the wiring board and the electrode of the electronic component are such that one of the electronic components facing the wiring substrate is wire-connected and the other is face-to-face connected. The composite electronic component described in.

Electrodes of electronic parts arranged opposite to each other on the wiring board are made common from one surface side of the wiring board by passing the wiring formed on the wiring board through through holes provided on the wiring board. Derived above
The composite electronic component according to any one of 1.

[0017]

With the arrangement structure as described above, the electronic components placed opposite to each other via the wiring board have their electrodes at positions facing the wiring board. Therefore, in the case where the electronic components are formed by arranging at least one of electrodes for power supply terminals, ground terminals, input terminals, output terminals, etc. at the same or near positions on the electronic components, The electrodes of the electronic components are arranged at positions substantially symmetrical with respect to the wiring board, and the length of the wiring connecting and connecting the electrodes can be minimized.

As described above, since the electrodes can be connected to each other on both sides of the wiring board by making the wiring as short as possible, it is possible to form a pattern with a sufficient density or distance so as not to interfere with other wiring. The wiring pattern as a whole can be a very simple pattern.

Further, since the wiring length can be shortened, the reliability of the composite electronic component can be improved and the speed can be increased. Further, since the wiring can be shortened, the area occupied by the wiring can be reduced, so that the degree of integration can be further improved.

[0020]

EXAMPLES Examples will be shown below to describe the features of the present invention in more detail.

FIG. 1 shows a schematic sectional view of the first embodiment of the present invention. In the figure, reference numeral 1 is a wiring board, and reference numerals 2 and 3
Indicates a bare chip IC (hereinafter referred to as “IC”). Here, the above IC2 and IC3 are of the same kind, and an electrode is formed on the surface on the element forming surface side, and the electrode arrangement pattern is also the same.
A few surfaces 2 ', 3'. IC2 and IC3 are arranged on both sides of the wiring board 1 so as to face each other so as to sandwich the wiring board 1. The IC2 has a surface 2 '
On the upper surface 1'of the wiring board 1 and the front surface 2 '
The electrodes formed on the wiring board 1 are connected to the wiring 4 on the wiring board 1 by wires 5 by a wire bonding method, and the IC 3 has its surface 3'formed on the lower surface 1 "of the wiring board 1 and on the surface 3 '. The formed electrodes are face-to-face connected to the connection portion of the wiring 6 on the wiring board 1 through the anisotropic conductive resin layer 7. The wiring 6 on the upper surface 1'side of the wiring board 1 is provided on the wiring board 1. By passing the wiring through the through hole 8 provided, the wiring 7 is connected to the wiring 7 on the lower surface 1 ′ side of the wiring board 1.

Next, FIGS. 2 and 3 show enlarged perspective views for explaining the arrangement state of the ICs 2 and 3 on both surfaces of the wiring board 1 in FIG. 1, and the first embodiment will be described in detail. Figure 2
As shown in FIG. 3, wirings 6a to 6f are arranged on the lower surface 1 ″ of the wiring board 1 so as to correspond to the respective electrodes 3a to 3f of the IC 3. The wirings 6a to 6f are the ends of the wiring board 1. It is linearly formed from the edge portion toward the connection portion with the corresponding electrodes 3a to 3f of the IC 3, and is connected to the wirings 4a to 4f (see FIG. 3) on the upper surface 1 ′ of the wiring board 1 in the middle thereof. The openings of the through holes 8a to 8f are arranged so that they can be formed.

In the IC 3, the electrodes 3a to 3f are respectively connected to the wirings 6a to 3f via the anisotropic conductive resin layer 7 provided by coating or printing at a predetermined position on the lower surface 1 "of the wiring substrate 1.
Face-to-face connection is arranged so as to be electrically connected to 6f.

Next, as shown in FIG. 3, the wiring board 1 is formed.
IC2 on the upper surface 1'of the wiring board 1 and I on the lower surface 1 "of the wiring board 1.
The electrodes 2a to 2f are mounted with the surfaces on which the electrodes 2a to 2f are formed facing upward so as to be plane-symmetrical to C3, and these electrodes 2a to 2f are respectively formed in the through holes 8a to 8f of the corresponding upper surface 1'of the wiring board 1. Wirings 4a to 4f linearly extending from the opening
Is connected to the end of the wire by wire bonding.

In this way, the ICs 2 are formed on both sides of the wiring board 1.
Since the IC 2 and the IC 3 are mounted, for example, the electrode 2a of the IC 2 is connected to the wiring 6a through the wiring 4a and the through hole 8a and is taken out from the lower surface 1 ″ of the wiring board 1 as the wiring common to the electrode 3a of the IC 3. IC
The electrodes 2a to 2f of No. 2 are the electrodes 3a to 2f of the IC 3, respectively.
The wiring can be easily shared with 3f.

The wiring board thus obtained can be made into a composite electronic component by connecting the wiring to external terminals. Further, for example, as shown in FIG. 4, when a plurality of ICs are circuit-wired with the power supply terminal Vcc, the ground terminal GND, and the I / O terminals L1 and L2 being the same (shared), as described above,
A plurality of wiring boards on which is mounted may be arranged in multiple layers using external terminals 9 having a plurality of stepped portions, as shown in FIG. 5, for example. Further, as shown in FIG. 6, it is also possible to connect the ICs to the external terminals 10 by disposing the ICs on the same wiring board so as to face each other in the same manner as in the first embodiment. By doing so, it is possible to obtain a composite electronic component with higher integration and thinner than before. However, each of the electrodes 3a to 3f of the IC 3 in FIGS. 5 and 6 is shown as being face-to-face connected with the wirings 6a to 6f of the wiring board 1 by a face-down method using bumps.

In the first embodiment, the wirings on the upper and lower surfaces of the wiring board 1 are taken out from one side by using the through holes 8. However, as shown in FIG. If a composite electronic component is obtained by forming 6 ′ and using an external terminal 11 having a clip-shaped connecting end as shown in FIG. 8, signals can be shared without using a through hole. By doing so, the wiring board can be formed more easily.

Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, the same type of mold package ICs 12 and 13 are mounted on both surfaces of the insulating substrate 1. The outer lead 12a of the mold package IC12 is bent in a normal direction and connected to the wiring 4 "of the wiring board 1 by soldering or the like. The outer lead 13a of the mold package IC13 is opposite to the outer lead 12a. It is bent in the direction and connected to the wiring 6 ″. In this way, the mold package IC
12 and 13 are wiring boards 1 with the main body in the same direction in cross section.
Therefore, the outer leads that can share signals can be arranged symmetrically with respect to the wiring board, and can be mounted in the same wiring pattern as in the first embodiment.

Further, according to the present invention, even if the electronic component has electrodes on both sides, the electrodes on one side are connected face-to-face by a face-down method or the like, and the electrodes on the other side are connected to wiring by wire connection, respectively. The electronic components can be applied by connecting the corresponding electrodes on the upper and lower surfaces of the wiring board in reverse to the face-to-face connection and the wire connection, and it is possible to obtain the same effect as that of the above embodiment.

As described in detail above, the present invention is particularly effective when a plurality of identical or similar electronic components and various terminals are connected in parallel in a memory module, a mirror circuit, or the like.

[0031]

According to the present invention, since electronic parts can be mounted on both sides of a wiring board with the shortest wiring, the wiring can be a simple pattern, and it is necessary to form a complicated wiring pattern as in the conventional case. Also, there is no need to wire the wiring board in multiple layers. Therefore, it is possible to provide a highly reliable composite electronic component in which noise such as crosstalk due to mutual interference between wirings due to wirings crossing or approaching each other can be reduced.

Further, as compared with the prior art, since the area occupied by the wiring can be reduced, higher integration can be achieved and the wiring can be shortened, so that higher speed can be achieved.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a first embodiment of the present invention.

FIG. 2 is an enlarged perspective view illustrating a mounted state of electronic components on a lower surface of the wiring board of FIG.

FIG. 3 is an enlarged perspective view illustrating a mounting state of electronic components on the upper surface of the wiring board of FIG.

FIG. 4 is an example of a circuit diagram of a composite electronic component obtained according to the first embodiment.

5 is a schematic cross-sectional view showing one structural example of a composite electronic component circuit-wiring according to the circuit diagram of FIG.

6 is a schematic cross-sectional view showing another structural example of the composite electronic component circuit-wiring according to the circuit diagram of FIG.

FIG. 7 is a schematic cross-sectional view showing another example of the wiring pattern in the first embodiment.

FIG. 8 is a structural example of a composite electronic component when the wiring pattern shown in FIG. 7 is used.

FIG. 9 is a schematic cross-sectional view showing a second embodiment of the present invention.

FIG. 10 is a schematic cross-sectional view showing a mounting structure when a conventional bare chip IC is used.

FIG. 11 is a schematic sectional view showing a mounting structure when a conventional mold package IC is used.

12 is a perspective view of a main part for explaining an electrode arrangement of the bare chip IC in FIG.

13 is a perspective view of a main part for explaining an electrode arrangement of the bare chip IC in FIG.

[Explanation of symbols]

 1 Wiring board 2,3 Bare chip IC 2a-2f, 3a-3f Electrode 4,4 ', 4 ", 6,6', 6" Wiring 5 Wire 7 Anisotropic conductive resin 8 Through hole 9,10,11 External terminal 12,13 Mold package IC 12a, 13a Outer lead

Claims (6)

[Claims] 1. A composite electronic component in which a plurality of electronic components each having an element formation surface as a surface are mounted on both sides of a wiring board, and at least one electronic component is provided on each side of the wiring board. A composite electronic component having a structure in which a front surface and a back surface of a component or a back surface and a front surface of the component are arranged to face each other so as to sandwich the wiring substrate. 2. The composite electronic component according to claim 1, wherein the electronic components arranged opposite to the wiring board have the same or similar electrode arrays for input terminals or output terminals. 3. The composite electronic component according to claim 1, wherein the electronic components arranged opposite to the wiring board have the same or similar electrode array for power terminals or ground terminals. 4. The composite electronic component according to claim 1, wherein one or both of the electronic components arranged facing the wiring board are bare chip components. 5. The wiring formed on the wiring board and the electrode of the electronic component are such that one of the electronic components arranged facing the wiring substrate is wire-connected and the other is face-to-face connected. 5. The composite electronic component according to any one of to 4. 6. The one surface side of the wiring board, wherein electrodes of electronic components arranged opposite to each other on the wiring board pass the wiring formed on the wiring board through through holes provided in the wiring board. Claim 1 commonly derived from
7. The composite electronic component according to any one of 5 to 5.