JPS6131620B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic circuit device, and provides a high-density-packaged thin electronic circuit device with a large heat dissipation effect, and in particular makes it possible to provide a high-power, high-density-packaged thin electronic circuit device. It is something.

The applicant has already proposed a high-density LSI mounting technology using a multilayer wiring structure combining polyimide film and metal frames. In other words, in order to achieve high-density packaging, this technology uses wireless bonding technology that directly connects the LSI electrode pads and the wiring on the film through fine through holes formed on the film, and also uses multilayer wiring. It uses a metal frame to achieve a minimum line width and spacing of about 50μ, making it possible to form wiring even on LSI chips, realizing a compact electronic circuit package with high density and extremely thinness. This is what I did. This conventional device is shown in FIG.

In FIG. 1, conductive wiring 3 formed on the first main surface of an insulating resin film 1 such as a polyimide film and an electronic component (for example, a semiconductor integrated circuit element) 4 are attached to the second main surface of the insulating resin film 1 by an adhesive layer 6. Further, the surface electrode 5 of 4 is electrically connected to 3 through the through hole 2 formed in 1 to constitute a high-density packaging thin electronic circuit device. The problem with this electronic circuit device is that electronic components 4 such as semiconductor chips and chip resistors are fixed to the insulating resin film 1 with low thermal conductivity, which results in poor heat dissipation and reduced reliability, especially for power devices. It has been difficult to realize high-power, high-density, thin electronic circuits using

Conventionally, as a solution to this problem, as shown in FIG. 1, a metal layer 7 serving as a heat sink of the electronic component 4 is formed by vapor deposition or the like in a region extending from the electronic component base to the adhesive layer 6, thereby enhancing the heat dissipation effect of the electronic component. An attempt is being made. However, in this method, (1) the area of the metal layer that becomes the heat sink is
It is not possible to obtain a large heat dissipation effect because it is limited by the planar area of the circuit device.

(2) Since connection to an external heat sink device is not taken into consideration, connection to an external heat sink device is difficult, and a large heat dissipation effect cannot be obtained.

(3) When implementing an electronic circuit device using a plurality of electronic components, a process such as photoetching is required to insulate the electronic component base portions from each other, which increases the cost.

There are drawbacks such as.

In view of these problems, the present invention has realized an electronic circuit device that has an extremely excellent heat dissipation effect and can mount multiple semiconductor chips thinly and firmly.
The structure of the present invention will be explained using the embodiment shown in FIGS. 2 and 3.

Fig. 2 shows the main parts of the LSI chip and heat sink used in the present invention, Fig. 2A is a plan view, and Fig. 2B is a sectional view taken along the line -' in the plan view. The items are given the same number. In FIG. 2, an insulating resin film is supported by a metal frame 8 (made of metal such as stainless steel, nickel, or Kovar) that also serves as an external lead. Conductor wiring 3 is formed. An adhesive layer 6 such as FEP is attached to the second main surface to form an electronic component, in this example an LSI.
A chip 4 is fixed with adhesive. This chip 4 is, for example, a power device. Here conductor wiring 3
is made of metals such as Cr, Cu, and Al. In addition to LSI chips, chip resistors, chip capacitors, transistor chips, etc. are often used as electronic components. Furthermore, the surface electrodes 5 of the LSI chip 4 and the conductor wiring 3 are electrically connected through a through hole 2 provided in a portion of the polyimide film. Note that this through hole 2 has a tapered shape as shown in the figure to make electrical connection less likely to break and improve reliability.

Next, the base portion of the LSI chip 4 is mechanically connected to a metal plate 10 serving as a heat sink by means of a conductive adhesive layer 9. If silicone-based silver paste is used as the conductive adhesive layer used here, the base portion 4 and the metal plate 10 can be easily mechanically connected. This connection method involves applying an adhesive such as silver paste on the base of the electronic component to which connection is desired or on the metal plate 10 corresponding to the position of the base of the electronic component to which connection is desired. and the metal plate 10 may be bonded together. Further, the metal plate 10 may be a thin plate of nickel, kovar, stainless steel, or the like with a thickness of about 10 to 100 μm.

Furthermore, as is clear from FIG. 2, a portion of the metal plate 10 is provided with a mounting portion 11 for attaching to an external device. The shape and size of the mounting portion 11 is determined depending on the external device, and a through hole 12 for mounting is provided in the center of the mounting portion 11, and the through hole portion is screwed to allow the mounting. Further, the attachment portion 11 may be attached to an external device using solder.

In this way, the electronic component, that is, the LSI chip 4
The base portion of is connected to a metal plate 10, and the heat generated by 4 is conducted to an external device via 10 and 11.
Here, as the external device, a heat sink or a heat sink device with a large heat sink effect for electronic equipment is used. Note that the metal plate 10 is bent in the figure to match the shape of the external device. In addition, if it is necessary to electrically insulate the base portion of some electronic parts from other electronic component base parts in an electronic circuit device using multiple electronic components, the desired electronic component base part may be insulated from other electronic component base parts. There are methods such as making it thinner than the base portion and not attaching an adhesive layer, or coating the desired electronic component base portion with an insulating resin. Further, according to this embodiment, when implementing an electronic circuit device using a plurality of electronic components, steps such as photoetching for insulating the electronic component base portions from each other are unnecessary.

Next, an embodiment of the present invention will be explained with reference to FIG.
In this example, multiple LSI chips are used, and only a predetermined LSI chip is connected electrically to a metal plate for heat dissipation, making it possible to implement a thin, high-density, and strong LSI.

In FIG. 3, the conductor wiring 3 formed on the first main surface of the polyimide film 1 supported by the metal frame 8 is connected to the second main surface of the film 1 through the through hole 2 provided in the film 1. It is electrically connected to the surface electrodes 5, 5' of the fixed LSI chips 4, 4'. In this respect, it is the same as the case in FIG.

The basic parts of the LSI chips 4 and 4' are buried with an insulating adhesive layer 13 made of FEP or the like, and
The insulating adhesive layer 13 on the back surface of the base portion of the chip 4 is removed, and a conductive adhesive layer 9 made of silver paste or the like is placed on this removed portion 14 to reduce the electrical connection between the metal plate 10 and the chip 4.
A physical connection is made.

To manufacture the structure shown in FIG. 3, the chips 4, 4' are fixed to the film 1, the wiring 3 and the electrodes of the chips 4, 4' are connected, and then the periphery and back surface of the chips 4, 4' are covered with insulating material. Cover with adhesive layer 13. This adhesive layer 13 is preferably made of thermoplastic material such as FEP. In other words, the adhesive layer 13 is buried at about 300°C.
This is done by heating FEP to make it into a fluid, and then cool it into a solid state. Then, in this solid state, only a part of the adhesive layer 13 on the back surface of the chip 4 is removed by oxygen plasma etching. Note that the adhesive layer on the back side of 4 and 4' should be thinner, and in this example it is 10 μm.
That's about it. Next, the above-mentioned silver paste is placed in the removed portion 14 to connect the chip 4 and the metal plate 10.
The LSI chip 4' of this embodiment needs to be insulated from the metal plate 10, and is electrically insulated from the metal plate 10 by an insulating adhesive layer 13.

In FIG. 3, as in FIG. 2, the metal plate 10 is connected to an insulating adhesive layer 13 and integrated with the LSI chip base, making the electronic circuit device rigid. The metal plate 10 has a mounting portion 11 for an external device, and when the electronic circuit device of the present invention is actually used, the metal plate 10 and the external lead portion 8 are connected to the external device. In this way, the base portion of the LSI chip 4, that is, the heat generating element, is connected to the metal plate 10, that is, the heat sink, and the amount of heat generated by the chip 4 is 1.
0,11 to the external device. or,
The base portion of the LSI chip 4' is connected to the metal plate 10 via an insulating adhesive layer 13.
Since 3 is as thin as about 10 μm, the amount of heat generated by 4' is also conducted to the external device via 10 and 11.

Note that any number of metal plates 10 according to the present invention can be provided to effectively dissipate heat from only the heat generating elements.

As is clear from FIG. 3, since the semiconductor integrated circuit substrates, that is, the LSI chips 4, 4', are in the form of thin flat chips, the front surface is adhered to the film 1, the back surface is adhered to the metal plate 10 for heat dissipation, and the chips are A structure is adopted in which the space between the film and the metal plate is filled with an adhesive layer 13. Therefore, many thin
The LSI chip can be uniformly mounted between the film 1 and the metal plate 10 without increasing the overall thickness, and the mounting state can also be made strong. This is extremely advantageous in that many LSIs can be mounted in a high-density, thin, and robust manner without sacrificing the features of thin LSI chips.

As described above, according to the present invention, the area of the metal plate serving as a heat sink can be arbitrarily selected without being limited by the planar area and number of LSI chips, so that a large heat dissipation effect can be obtained. Furthermore, in the present invention, since a part of the metal plate serving as a heat sink has a mounting portion for an external device, a large heat dissipation effect can be obtained, and in particular, it is possible to provide a high-power, high-density packaging thin electronic circuit device. In addition, the present invention enables uniform and strong thin mounting while having the heat dissipation structure of many LSI chips, and greatly contributes to expanding the range of applications of high-density thin electronic circuit packages including LSI chips. It is something.

[Brief explanation of the drawing]

FIG. 1 is a structural sectional view of a conventional film-mounted electronic circuit device, FIG. 2A is a plan view of the main part of the film-mounted electronic circuit device used in the present invention, and FIG.
3 is a structural sectional view of a film-mounted electronic circuit device according to an embodiment of the present invention. 1... Insulating resin film, 2... Insulating resin film through hole, 3... Conductor wiring, 4, 4'... Electronic component (LSI chip), 5... Surface electrode of electronic component, 6... Adhesive layer, 8... Metal frame, 9... Conductive adhesive layer, 10... Metal plate, 11... Mounting part, 1
2... Attachment portion through hole, 13... Insulating adhesive layer. 〓〓〓〓

Claims (1)

[Claims] 1 One main surface of a plurality of semiconductor integrated circuit substrates having electrodes is fixed to the other main surface of a heat-resistant insulating substrate on which a wiring metal layer is selectively formed on one main surface via an adhesive layer. , the electrodes of the substrate and the wiring metal layer are electrically connected through through holes formed in the insulating substrate, and the other main surface of the plurality of semiconductor integrated circuit substrates is fixed to a heat dissipation metal plate. A mounting portion for connection to the outside is provided in a part of the metal plate, and an insulating or conductive adhesive layer is filled between the plurality of semiconductor integrated circuit substrates and the metal plate, so that the plurality of semiconductor integrated circuit substrates An electronic circuit device characterized in that an insulating adhesive layer is provided between the insulating substrate and the metal plate.