JP2000133890A - Hybrid module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid module with improved reliability. SOLUTION: A circuit board 11 is formed by jointing a flexible board 17 having flexibility and a hard printed board 18. A recessed part 16 is formed on a main face 15 of the circuit board 11 so that the flexible board 17 is exposed. A circuit part 13 is mounted on the flexible board 17 which is exposed to the recessed part 16. Since the stress added to the circuit part 13 is relaxed by the flexible board 17, reliability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid module for forming an electronic circuit by mounting a chip component such as a multilayer capacitor or a multilayer inductor or a circuit component such as a semiconductor component on a circuit board on which a circuit pattern is formed. Things.

[0002]

2. Description of the Related Art Conventionally, a hybrid module of this type has been known as shown in FIG. FIG.
FIG. 3 is a side sectional view showing a conventional hybrid module. The hybrid module 100 has a circuit board 101 on which a chip-shaped electronic component 102 and a circuit component 103 such as a semiconductor element having heat generation are mounted.

The circuit board 101 is made of aluminum nitride ceramic having good thermal conductivity. The chip-shaped electronic component 102 is soldered to a circuit pattern 106 formed on the circuit board 101. Circuit component 103
Are bonded onto the circuit pattern 106 via the solder bumps 103a. Here, the chip-shaped electronic component 102
Is a passive component such as a multilayer capacitor. Also,
The circuit component 103 is an active component such as an FET, for example.

On the side of the circuit board 101, a parent circuit board S
A terminal electrode 101a for connecting to the terminal is formed.
This terminal electrode 101a is soldered to a circuit pattern Sp formed on the parent circuit board S. The main surface 101b of the circuit board 101 facing the parent circuit board S is joined via a conductor film Sf formed on the parent circuit board S. This conductive film Sf is used for the hybrid module 100
Is efficiently conducted to the parent circuit board S, and is made of a member having good thermal conductivity.

With such a configuration, in the hybrid module 100, heat generated from the circuit components 103 mounted on the circuit board 101 is generated by the circuit board 101 and the conductor film Sf via the conductor circuit board S or the ground. The heat is conducted to the conductor film having the area and is radiated.

[0006]

However, in this hybrid module 100, heat generated in the circuit component 103 is conducted to the circuit board 101 via the solder bumps 103a of the circuit component 103,
And through the conductor film Sf to the parent circuit board,
There was a problem that heat conduction was low. Further, there is a problem that aluminum nitride-based ceramics used for increasing the thermal conductivity are more expensive than general alumina-based substrate materials and lack economical efficiency. Furthermore, since all the components are mounted on one side of the circuit board 101, there is a problem that it is difficult to increase the density.

In order to solve such a problem, a hybrid module as shown in FIG. 9 has been proposed.
FIG. 9 is a side sectional view showing another conventional hybrid module.

In this hybrid module 110,
A recess 111 is formed on the back side of the circuit board 101, and the circuit component 103 is mounted in the recess 111. Specifically, the concave portion 111 is formed on the back surface of the circuit board 101 so that the circuit pattern 106 is exposed on the bottom surface. The circuit component 103 is mounted on the circuit pattern 106 in the recess 111 via the solder bump 103a.
A heat sink 112 is adhered to the front side of the circuit component 103. The recess 111 is filled with a sealing resin 113 for sealing the circuit component 103.

With such a configuration, heat generated in the circuit component 103 is conducted to the heat radiating plate 112, and the heat radiating plate 1
Since the heat is radiated to the parent circuit board via the line 12, high heat radiation efficiency can be obtained. In addition, since components can be arranged on both sides of the circuit board 101, high density can be realized.

However, in this hybrid module 110, one side of the circuit component 103 is mounted on the circuit board 10.
1, and the other surface is bonded to the heat sink 112. For this reason, when a difference in distortion of each member occurs due to heat generated during mounting of the hybrid module 110 or heat generated from the circuit component 103, the stress due to the difference in distortion cannot be released or absorbed, and peeling occurs at each interface (adhesion surface). May occur. As a result, there is a problem that the reliability of the hybrid module 110 is reduced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a hybrid module with improved reliability.

[0012]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a circuit board having a recess formed therein, and a circuit component having heat generation mounted in the recess of the circuit board. Wherein the circuit board comprises a first circuit board having flexibility and a second circuit board having rigidity. And a first circuit board is exposed at a bottom surface of the recess, and the circuit component is mounted on the first circuit board within the recess of the circuit board. Suggest what to do.

According to the present invention, since the circuit board is formed by the first circuit board having flexibility and the second circuit board having rigidity, the stress generated in the hybrid module is generated by the first circuit board. Is alleviated by In particular, since the circuit components are mounted on the first circuit board, the stress applied to the circuit components is reduced by the first circuit board. As a result, the bonding of the circuit components can be reliably maintained, and the reliability is improved.

According to a second aspect of the present invention, in the hybrid module according to the first aspect, the joint between the first circuit board and the second circuit board has the circuit component on the first circuit board mounted thereon. A feature characterized by being formed outside the region that has been set.

According to the present invention, since the first circuit board is not joined to the second circuit board in the area where the circuit components are mounted, the first circuit board is not bonded to the area where the circuit components are mounted on the first circuit board. The region extending over the joint between the first circuit board and the second circuit board ensures that the stress applied to the circuit component is reduced.

According to a third aspect of the present invention, there is provided the hybrid module according to the first or second aspect, wherein the circuit component is mounted face-down. Suggest what to do.

According to the present invention, when the hybrid module is mounted on the parent circuit board, the surface of the circuit component facing the parent circuit board is joined to the parent circuit board, so that the heat generated in the circuit component can be efficiently dissipated. The heat can be radiated to the parent circuit board. Other functions and effects are the same as those of the first or second aspect.

According to a preferred embodiment of the present invention, in the fourth aspect of the present invention, in the hybrid module according to any one of the first to third aspects, the circuit component is provided on a side facing the parent circuit board with a heat sink. Are bonded, and the heat generated in the circuit components is radiated to the parent circuit board through the heat radiating plate.

According to the present invention, when the hybrid module is mounted on the parent circuit board, the heat generated in the circuit parts is efficiently transferred to the parent circuit by bonding the heat sink adhered to the circuit parts to the parent circuit board. Heat can be dissipated to the substrate. Other functions and effects are the same as those of the first or second aspect.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A hybrid module according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view of the hybrid module according to the first embodiment, and FIG. 2 is a longitudinal sectional view of a main part of the hybrid module according to the first embodiment.

The hybrid module 10 is used by being mounted on a parent circuit board S. The hybrid module 10 includes a circuit board 11 on which a circuit pattern is formed, a plurality of chip-shaped electronic components 12 mounted on the circuit board 11, and a circuit component such as a semiconductor element having heat generation mounted on the circuit board 11. 13 and the circuit component 13
The heat radiating plate 14 for radiating the heat generated in the main component is a main component.

The circuit board 11 has a recess 16 formed in the main surface 15 facing the parent circuit board S. The circuit component 13 is mounted on the bottom surface of the recess 16. A heat dissipation plate 14 is adhered to the upper surface of the circuit component 13. The heat radiating plate 14 is a metal plate slightly larger than the upper surface of the circuit component 13, and is, for example, copper or a 42 alloy (nickel: iron =
(42:58 alloy). The heat radiating plate 14 is arranged such that the surface facing the parent circuit board S is substantially flush with the main surface 15 of the circuit board 11.

The circuit board 11 is formed by joining a flexible board 17 and a printed board 18 together. The circuit board 11 has a structure in which a flexible board 17 is arranged between two printed boards 18 and stacked. The printed circuit board 1 on the side facing the parent circuit board S
8 is formed with a hole serving as the concave portion 16. Thereby, the flexible substrate 17 is exposed on the bottom surface of the concave portion 16.

The flexible substrate 17 is a printed circuit board using a flexible insulating substrate, for example, a polyimide film copper-clad printed circuit board. A predetermined circuit pattern is formed on the flexible substrate 17. The circuit component 13 is mounted on the flexible substrate 17 in the recess 16.

The circuit component 13 is a heat-generating semiconductor chip such as a GaAs MES type FET. Also,
The circuit component 13 is a flip chip in which a bump 13 a serving as a protruding electrode is formed on the mounting surface side of the flexible substrate 17. Therefore, the circuit component 13 is mounted on the flexible board 17 face down. Bump 13a
Is formed of, for example, solder, Au, or the like. The mounting portion of the circuit component 13 is filled with an insulating resin 24 for sealing.

The printed board 18 is a multi-layer board using a hard insulating board, for example, an epoxy-based insulating layer is used. The printed circuit board 18 has a predetermined pattern of electrodes 19 and via holes 20 connecting between the electrodes 19. The electrode 19 of the printed board 18 is joined to the circuit pattern of the flexible board 17. Here, the joint 21 between the printed board 18 and the flexible board 17 is formed outside the area where the circuit component 13 is mounted. That is, the printed board 18 and the flexible board 17 are joined around the circuit component 13. Further, this joint 21 is formed by soldering or the like.

A surface opposite to the main surface 15 of the circuit board 11,
That is, the chip-shaped electronic component 12 connected to the electrode 19 is soldered to the upper surface of the circuit board 11. Also,
External electrodes 2 connected to the electrodes 19 are provided on the side surfaces of the circuit board 11.
2 are formed. Further, a metal case 23 is mounted on the upper surface side of the circuit board 11.

According to such a hybrid module 10, the heat generated in the circuit components 13 is radiated to the parent circuit board S via the radiator plate 14. Further, since the circuit board 11 is formed by the flexible printed circuit board 17 having flexibility and the hard printed circuit board 18, the stress generated in the hybrid module 10 is reduced by the flexible printed circuit board 17. In particular, since the circuit component 13 is mounted on the flexible substrate 17, the stress applied to the circuit component 13 is reduced by the flexible substrate 17. Thereby, the connection between the circuit component 13 and the flexible substrate 17 can be reliably maintained, and the reliability is improved.

More specifically, since the flexible board 17 is not bonded to the printed board 18 in the area where the circuit components 13 are mounted, the flexible board 17 Region A over joint 21 with printed circuit board 18
The stress applied to the circuit component 13 is reduced by the dotted ellipse region in FIG. Therefore, the circuit component 1
3 and the flexible substrate 17 can be reliably maintained, and the reliability is improved.

In this embodiment, the heat generated by the circuit component 13 is radiated to the parent circuit board S via the radiator plate 14. However, as shown in FIG. good. In this case, if the depth and the like of the concave portion 16 are adjusted so that the upper surface of the circuit component 13 is flush with the main surface 15 of the circuit board 11, the heat generated in the circuit component 13 is directly transferred to the parent circuit board S. Heat can be dissipated.

(Second Embodiment) Next, a second embodiment of the present invention will be described.
The hybrid module according to the embodiment will be described with reference to FIGS. FIG. 4 is a longitudinal sectional view of the hybrid module according to the second embodiment, and FIG. 5 is a longitudinal sectional view of a main part of the hybrid module according to the second embodiment. In the drawings, the same members as those of the first embodiment are denoted by the same reference numerals.

This hybrid module 30 differs from the hybrid module 10 according to the first embodiment in the structure of the circuit board 31. That is, as shown in FIG. 4, the flexible substrate 32 forming the circuit board 31 is formed to have the same shape as the bottom shape of the concave portion 16. The flexible board 32 is a circuit board 31
And the printed circuit board 33 at the bottom surface of the recess 16. The joint part 34 between the flexible board 32 and the printed board 33 is similar to the first embodiment,
Is formed outside the area in which is mounted. That is, the electrode 36 of the printed board 33 and the flexible board 32 are joined at the periphery of the recess 16. Circuit parts 13
Is mounted on the flexible substrate 32 in the recess 16 similarly to the first embodiment. Heat sink 1
4 is bonded to the upper surface side of the circuit component 13.

According to the hybrid module 30, the same operations and effects as those of the first embodiment can be obtained. That is, the heat generated in the circuit component 13 is radiated to the parent circuit board via the radiator plate 14. Further, since the circuit board 31 is formed by the flexible printed board 32 having flexibility and the hard printed board 33, the stress generated in the hybrid module 30 is reduced by the flexible board 32. In particular, the flexible substrate 3
2 is not bonded to the printed circuit board 33 in the area where the circuit component 13 is mounted,
In (2), the stress applied to the circuit component 13 is reduced by the region B (the dotted elliptical region in FIG. 5) extending from the region where the circuit component 13 is mounted to the joint portion 34 between the flexible board 32 and the printed board 33. Therefore, the bonding between the circuit component 13 and the flexible substrate 32 can be reliably maintained, and the reliability is improved.

In this embodiment, the heat generated by the circuit component 13 is radiated to the parent circuit board via the radiator plate 14, but the radiator plate 14 may not be provided. In this case, if the depth and the like of the concave portion 16 are adjusted so that the upper surface of the circuit component 13 is flush with the main surface 15 of the circuit board 31, the heat generated in the circuit component 13 is directly radiated to the parent circuit board. can do.

(Third Embodiment) Next, a third embodiment of the present invention will be described.
The hybrid module according to the embodiment will be described with reference to FIGS. FIG. 6 is a longitudinal sectional view of the hybrid module according to the second embodiment, and FIG. 7 is a longitudinal sectional view of a main part of the hybrid module according to the second embodiment. In the drawings, the same members as those of the first embodiment are denoted by the same reference numerals.

The hybrid module 40 differs from the hybrid module 10 according to the first embodiment in the structure of the circuit board 41. That is, as shown in FIG. 6, the circuit board 41 includes a flexible board 42 arranged on the upper surface side of the circuit board 41 and a printed board 43 arranged on the parent circuit board side of the flexible board 42.
Are formed. The printed circuit board 43 has a hole serving as the concave portion 16, so that the flexible substrate 42 is exposed on the bottom surface of the concave portion 16. The circuit component 13 is mounted on the flexible substrate 42 in the recess 16 as in the first embodiment. The heat sink 14 is adhered to the upper surface of the circuit component 13. The chip-shaped electronic component 12 is mounted on the upper surface of the flexible substrate 42.

According to the hybrid module 40, the same operations and effects as those of the first embodiment can be obtained. That is, the heat generated in the circuit component 13 is radiated to the parent circuit board via the radiator plate 14. Further, since the circuit board 41 is formed by the flexible printed circuit board 42 having flexibility and the hard printed circuit board 43, the stress generated in the hybrid module 40 is reduced by the flexible printed circuit board 42. In particular, the flexible substrate 4
2 is not bonded to the printed circuit board 43 in the area where the circuit component 13 is mounted,
In a region C extending from the region where the circuit component 13 is mounted to the joint between the flexible substrate 42 and the printed circuit board 43
The stress applied to the circuit component 13 is reduced by the dotted ellipse region in FIG. Therefore, the circuit component 1
3 and the flexible substrate 42 can be reliably maintained, and the reliability is improved.

In this embodiment, the heat generated by the circuit component 13 is radiated to the parent circuit board via the radiator plate 14, but the radiator plate 14 may not be provided. In this case, if the depth and the like of the concave portion 16 are adjusted so that the upper surface of the circuit component 13 is flush with the main surface 15 of the circuit board 41, heat generated in the circuit component 13 is directly radiated to the parent circuit board. can do.

As described above, in the first to third embodiments, a polyimide film copper-clad printed circuit board is used as a flexible substrate. However, the present invention is not limited to this, and another substrate may be used. Further, an epoxy-based printed board is used as the hard board, but the present invention is not limited to this, and another board may be used. For example, a ceramic substrate may be used.

In the first to third embodiments, the flip-chip method is used for the face-down mounting of circuit components, but other mounting methods may be used. For example, a beam read method is used.

[0041]

As described above in detail, according to the first aspect of the present invention, since the circuit board is formed by the first circuit board having flexibility and the second circuit board having rigidity, the hybrid module is provided. The stress generated in the substrate is reduced by the first circuit board. In particular, since the circuit component is mounted on the first circuit board, the stress applied to the circuit component is the first.
Of the circuit board. As a result, the bonding of the circuit components can be reliably maintained, and the reliability is improved.

According to the second aspect, since the first circuit board is not bonded to the second circuit board in the area where the circuit parts are mounted, the circuit parts are mounted on the first circuit board. The region extending from the region where the first circuit board and the second circuit board are joined to each other ensures that stress applied to the circuit component is reduced.

Further, according to the third and fourth aspects of the present invention, when the hybrid module is mounted on the parent circuit board, the heat generated in the circuit components can be efficiently radiated to the parent circuit board. Other effects are described in claim 1.
Or 2 is the same.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a hybrid module according to a first embodiment.

FIG. 2 is a longitudinal sectional view of a main part of the hybrid module according to the first embodiment;

FIG. 3 is a longitudinal sectional view of a hybrid module according to another example of the first embodiment.

FIG. 4 is a longitudinal sectional view of a hybrid module according to a second embodiment.

FIG. 5 is a longitudinal sectional view of a main part of a hybrid module according to a second embodiment;

FIG. 6 is a longitudinal sectional view of a hybrid module according to a third embodiment.

FIG. 7 is a longitudinal sectional view of a main part of a hybrid module according to a third embodiment;

FIG. 8 is a longitudinal sectional view of a conventional hybrid module.

FIG. 9 is a longitudinal sectional view of another conventional hybrid module.

[Explanation of symbols]

10, 20, 30 ... hybrid module, 11, 3
1, 41: circuit board, 12: chip-shaped electronic component, 13:
Circuit components, 14: heat sink, 15: main surface, 16: recess, 1
7, 32, 42: Flexible substrate, 18, 33, 43
... printed circuit board, 19 ... electrode, 20 ... via hole, 2
1, 31: joint, 22: external electrode, 23: case, 2
4: Insulating resin

Claims (4)

[Claims] 1. A circuit board having a recess formed therein, and a heat-generating circuit component mounted in the recess of the circuit board, wherein a side of the circuit board having the recess formed is opposed to a parent circuit board. In the hybrid module to be mounted, the circuit board is formed by joining a first circuit board having flexibility and a second circuit board having rigidity, and a first board is provided on a bottom surface of the concave portion. A hybrid module, wherein a circuit board is exposed, and the circuit component is mounted on the first circuit board in a recess of the circuit board. 2. A connection part between the first circuit board and the second circuit board is formed outside a region where the circuit components are mounted on the first circuit board. 2. The hybrid module according to 1. 3. The hybrid module according to claim 1, wherein the circuit component is mounted face-down. 4. The circuit component, wherein a heat radiating plate is bonded to a side facing the parent circuit board, and heat generated in the circuit component is radiated to the parent circuit board via the heat radiating plate. The hybrid module according to claim 1.