JPH0897355A - Hybrid integrated circuit device and manufacture - Google Patents

Abstract

PURPOSE: To improve reliability of the fixing portion, on the occasion of obtaining a multilayer substrate by bonding an insulating substrate on a metal substrate, by controlling influence of semiconductor elements and parts of both substrates as much as possible without allowing re-fusion of hardended solder on the insulating substrate for soldering on the metal substrate. CONSTITUTION: A semiconductor element 35 for a high amplitude signal is mounted on a metal substrate 30 and an insulating substrate 38 is mounted in the region corresponding to a removed area 44. Moreover, a fixing part 45 is also provided at the superimposed area and this fixed area is also fused simultaneously with fusing of solder on the metal surface 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid integrated circuit device and a method of manufacturing the same, and more particularly to a multi-layer substrate to improve the packaging density.

[0002]

2. Description of the Related Art A conventional structure will be described with reference to FIGS. Generally, a multilayer substrate structure is described in, for example, Japanese Patent Application No. 2-201219 (H05K 3/36), and a printed circuit board 11 is mounted on the lower substrate 10 to form a multilayer substrate. Conductive paths 12 and conductive lands 13 are formed on the first substrate 10, and chip resistors 14 and semiconductor elements 15 are electrically connected thereto via solder. Printed circuit board 1
1, a chip resistor or a semiconductor element is connected to a conductive land 16 or a conductive land through solder, which is also omitted in the drawing.

The printed circuit board 11 is a lower layer substrate 10.
Since it is adhered to, it is not common to mount it on the back surface.

[0004]

Generally, the lower substrate 10 is used.
There are some printed circuit boards 11 to which semiconductor elements and parts are fixed via solder. In particular, the printed circuit board 11
When semiconductor elements and parts are mounted and supplied, and the semiconductor elements 15 and the like are soldered to the lower layer substrate 10 after being bonded to the lower layer substrate 10, the heat applied to the solder causes the lower layer substrate to move. Since it is added to the printed circuit board through the solder, the solder-bonded portion of the printed circuit board is melted again and causes a problem such as deterioration. In particular, when the lower substrate is a metal substrate, the heat conduction is good, which is more serious.

On the other hand, the printed circuit board 11 and the lower substrate 10
However, since they are fixed via an adhesive, there is a problem that the substrates warp or peel off due to the difference in thermal expansion coefficient between the two substrates.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. First, at least a part of a metal substrate under an insulating substrate is hollowed out, and the insulating substrate corresponding to the hollowed-out region is formed. On the front surface and / or the back surface of the second
This is solved by mounting a semiconductor element and / or a second component.

Secondly, after mounting an insulating substrate having a semiconductor element and / or components fixed to the hollowed-out portion of the metal substrate, the semiconductor element is mounted on the conductive path and / or the conductive land of the metal substrate via solder. The solution is to fix it. Thirdly, at the same time as the step of placing the insulating substrate on the metal substrate and fixing the semiconductor element to the conductive path and / or the conductive land of the metal substrate via the solder, the insulating substrate and the metal substrate are brought into contact with each other. This is solved by fixing the solder in the area.

[0008]

In the first place, a hollow is provided in the metal substrate corresponding to the intended mounting area of the insulating substrate, whereby a space is provided therein. Therefore, since the insulating substrate does not directly contact the heat source (for example, the heater), the solder provided on the fixed portion of the insulating substrate does not reach the melting point and does not melt. Also, if a large signal semiconductor element is mounted on a metal substrate and an element for small signal with less heat generation is mounted on an insulating substrate,
Due to the hollow portion, the heat of the large signal element is not transmitted to the insulating substrate, and at the same time, since this element is mounted on the metal substrate, heat can be radiated to the outside through the metal substrate.

Secondly, by providing the hollow portion,
By fixing the insulating substrate to the metal substrate and then melting the solder of the metal substrate, the elements of the metal substrate can be fixed without melting the solder of the insulating substrate again. Thirdly, since the heat from the heat source can be satisfactorily transferred to the insulating substrate in the region of the insulating substrate that is in contact with the metal substrate, that is, in the periphery of the cut-out portion, two sheets are formed simultaneously with the solder melting process of the metal substrate. The substrate can be fixed. Therefore, when used in combination with the fixing of the two substrates with the adhesive, the adhesive strength is increased. Further, even if an adhesive is not used together, since there is a cutout portion, the distortion generated between the two substrates is smaller than in the conventional case, so that warpage and peeling can be prevented.

[0010]

Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is a plan view of the embodiment,
First, there is a metal substrate 30, on which conductive paths 31 and conductive lands 32 are attached. This metal substrate 30 is A
An oxide film 33 is formed on the surface of the substrate 1. Although this oxide film is formed by anodizing both surfaces by anodic oxidation, it may be formed by thermal oxidation or may be formed by deposition. Further, at least one main surface is covered with an insulating resin 34 having an adhesive property such as an epoxy resin or a polyimide resin, and the conductive path 31 is attached by hot pressing. The conductive path 31 is made of Cu, and is adhered to the entire surface and then etched and patterned with a solution of ferric chloride or the like. The conductive land 32 is
In the area where the bare chip-shaped first semiconductor element 35 and the like are fixed, since a large-signal heating element is mounted here,
A heat sink 36 of Cu or the like is fixed to the lower layer of the chip 35 via solder or the like, and is integrated with the conductive path,
It looks like an island. Although the semiconductor element 35 may be an IC chip or an LSI chip, it is a power transistor in the figure, and the base electrode and the emitter electrode on the surface are wire-bonded by metal thin wires to a pad integrated with a part of the wiring. Furthermore, a first component 37 such as a chip resistor or a chip capacitor is connected to the conductive path via solder.

On the other hand, there is an insulating substrate 38 for double-sided mounting, and here, there is a so-called printed circuit board made of materials such as glass epoxy, paper epoxy, paper phenol and polyimide. However, a sheet-shaped flexible substrate may be used. The insulating substrate 38 is provided with the second conductive paths 39 and the second conductive lands 40 similarly to the above-described metal substrate, and the second component and the second semiconductor element are connected to the second conductive lands in the second conductive paths. A second semiconductor element such as a transistor is fixed to 40 via solder or the like. Since it is of course double-sided mounting, the above-mentioned structure is also formed on the back surface of the insulating substrate 38 via the through holes.

Here, the electrical contact between the circuit of the metal substrate 30 and the insulating substrate 38 is realized by the three examples shown by 41, 42 and 43. 41 has a bonding pad extending at the boundary between both substrates and is realized by a thin metal wire. Further, since the bonding is pressurized, it is preferable that one electrode is provided not on the cutout portion but on the overlapping portion of both substrates. The electrode of 42 is close to both boundaries, and both are electrically connected by soldering. In particular, the electrode to be connected does not need to be the overlapping portion, but it is better to be in the overlapping portion because the solder is more likely to straddle between the two when the electrodes are close to each other. Further, in 43, the wiring of the metal substrate 30 extends to a lower layer of the overlapping portion of the insulating substrate 38, and the electrode extending from the wiring thereabove through a through hole indicated by a circle. It is electrically connected by solder. Therefore, the circuit of the metal substrate and the circuit of the insulating substrate are electrically connected to achieve a desired IC circuit.

A feature of the present invention is a hollowed-out portion 44 of the dotted line shown in the insulating substrate 38, which is formed so that the periphery of the insulating substrate overlaps with the metal substrate 30 and does not contact the other metal substrate. It is provided on the substrate. Therefore, a thick component or a semiconductor element can be mounted on the back surface of the insulating substrate 38, and the metal substrate 30 and the insulating substrate 38 in the dotted line region are not fixed to each other with an adhesive or the like. It is possible to reduce the strain between the substrates and the stress applied to the element or component due to the.

If a large-signal heat generating element is mounted on the metal substrate 30 and a small-signal heat generating element is mounted on the insulating substrate, the heat from the large-signal element is cut out. Since it is present, it is difficult to reach the insulating substrate, and the metal substrate 30
Since it is mounted on top, heat from the large-signal element can be dissipated, and the thermal influence on the insulating substrate and the elements and components mounted on it can be minimized.

As will be described later, an insulative substrate 38 having a second component and a second semiconductor element fixed to both sides by solder is prepared in advance, and this is fixed to the metal substrate 30 before the first metal substrate is bonded. When fixing a component or the first semiconductor element via solder, for example, when the solder is melted by a heater applied to the lower layer of the substrate as a heat source, the insulating substrate 38 is not directly heated by the heat source because of the hollow portion 44. , There is a time lag in temperature rise. Therefore, even if the solder on the metal substrate is melted, the solder on the insulating substrate is not melted, and the fixed portion is not melted again.

On the other hand, the overlapping portion of the metal substrate 30 and the insulating substrate 38 is fixed by, for example, an adhesive.
You can also use That is, the solder lands 45 (which may be provided on the back surface) provided around the insulating substrate, the through holes and the solder lands in the metal substrate region whose position coincides with the through lands are provided at two or three points. You may connect through solder. Alternatively, the back surface of the insulating substrate and the front surface of the metallic substrate may be fixed at two points. In this case, since there is a connection point in the overlapping portion of the two substrates, the heat from the heater can be transferred to the overlapping portion of the insulating substrate. can do. Therefore, if it is used in combination with an adhesive, the adhesive strength of both substrates can be improved, and the adhesive can be omitted by interspersing a large number of solder lands in the overlapping portion. Generally, most adhesives heat and solidify,
This heating can be omitted, and the deterioration of the substrate can be prevented.

Next, the manufacturing method will be described. First, a metal substrate 30 to which the conductive paths 31 and the conductive lands 32 are attached and an insulating substrate 38 to which the second component and the second semiconductor element are fixed are prepared. Here, the metal substrate is provided with a cutout portion 44 as shown in advance. Then, the insulating substrate 38 is mounted on the hollow portion 44 of the metal substrate 30.
At this time, it may be fixed with an adhesive. Further, the solder provided in advance is melted by an external heat source, for example, a heater or the like, and the elements and parts of the metal substrate, the external leads and the fixing portion are fixed by the solder. Here, as the solder of both substrates, solder cream may be placed before heating, or solder may be placed during heating.

Therefore, the solder on the cut-out portion solidified on the insulating substrate 38 is prevented from remelting and preventing the solder fixing deterioration of the second semiconductor element or the second component. Further, since the connecting portion 42 and the fixing portion 45 provided in the overlapping portion are melted, electrical connection between both substrates and fixing of both substrates can be realized. Finally,
Although not shown in the drawing, it is stored in a box-shaped storage case or the like, and a resin is injected therein as needed and sealed.

[0019]

As is apparent from the above description, the first
In addition, since the metal substrate is provided with a hollow portion and the insulating substrate is mounted thereon, a thick semiconductor element or component can be mounted on both sides of the insulating substrate, and the semiconductor element or component to be mounted in the hollow portion can be mounted. Since it is hard to be affected by the heating element on the metal substrate, malfunction of the circuit, deterioration of the circuit substrate, etc. can be prevented. Therefore, in the power circuit, if the large signal semiconductor element is mounted on the metal substrate and the other small signal semiconductor element is mounted on the insulating substrate, the reliability of the entire circuit can be maintained. Further, the semiconductor element or component on the back surface of the insulating substrate can be mounted with a certain thickness due to the hollow portion, and the adhesive for fixing between the two substrates can be omitted. It is also possible to eliminate the influence of stress due to time.

Secondly, even if the semiconductor element or component is mounted on the insulating substrate in advance and placed on the metal substrate and then the semiconductor element or component is fixed on the metal substrate via solder, the cutout portion Since there is no metal substrate, the temperature of the insulating substrate in this region does not rise, and the fixing portion soldered in advance does not remelt, which leads to improvement in reliability. Thirdly, the overlapping portion with the metal substrate can transfer the heat from the heater to the insulating substrate, and the solder for fixing the two substrates, and the solder for electrical connection provided at the boundary of both substrates. Can be performed simultaneously when the solder on the metal substrate is melted. Therefore, simplification of the process can be realized.

[Brief description of drawings]

FIG. 1 is a plan view illustrating an embodiment of the present invention.

FIG. 2 is a cross-sectional view of FIG.

FIG. 3 is a plan view of a conventional hybrid integrated circuit device.

4 is a cross-sectional view of FIG.

[Explanation of symbols]

 30 Metal Substrate 31,39 Conductive Path 32,40 Conductive Land 35 Semiconductor Element 37 Parts 38 Insulating Substrate 44 Cutout

Claims (3)

[Claims] 1. A metal substrate whose surface is treated with insulation, a first conductive path and a first conductive land which are adhered to the metal substrate with an insulating adhesive, and the first conductive path and the first conductive land. A first semiconductor element and a first electrically connected to
A component, an insulating substrate for double-sided mounting mounted on at least a part of the surface of the metal substrate, a second conductive path and a second conductive path that are attached to both surfaces of the insulating substrate and are electrically connected at least in part. A second conductive land, and a second conductive path and a second conductive land.
A second semiconductor element and a second component electrically connected to the conductive land; and a connecting means for electrically connecting the first conductive path and the first conductive pad to the second conductive path and the second conductive pad. At least, a first semiconductor element for large signal is mounted on the metal substrate, a second semiconductor element for small signal is mounted on the insulating substrate, at least the metal substrate of the lower layer of the insulating substrate A hybrid integrated circuit device, wherein a part is hollowed out, and the second semiconductor element and / or the second component is mounted on the back surface of the insulating substrate corresponding to the hollowed out region. 2. A step of preparing a metal substrate partly hollowed out to form conductive paths and conductive lands and an insulating substrate arranged in the hollowed-out region, and a conductive path of the insulating substrate and And / or fixing the semiconductor element to the conductive land via solder, and mounting the insulating substrate on the metal board, and then fixing the semiconductor element to the conductive path and / or conductive land of the metal board via solder A method of manufacturing a hybrid integrated circuit device, comprising: 3. A step of preparing a metal substrate having a conductive path and / or a conductive land formed on a surface thereof and an insulating substrate arranged in a hollow portion of the metal substrate, and a conductive path and / or of the insulating substrate. A step of fixing a semiconductor element to a conductive land via solder; a step of mounting the insulating substrate on a hollow portion of the metal board, and fixing the semiconductor element to a conductive path and / or a conductive land of the metal board via solder At the same time as the step, a method for manufacturing a hybrid integrated circuit device is characterized in that the insulating substrate and the metal substrate are fixed to each other via solder in a region in contact with each other.