JPH01251786A - Electronic circuit device - Google Patents

Abstract

PURPOSE:To improve the reliability of connection between an electronic circuit module and a printed wiring board by adding indium to metal particles in a conductive adhesive layer for connecting electrode terminals of an electronic circuit module and electrodes of a printed wiring board. CONSTITUTION:For an electronic circuit module 8, semiconductor elements 1, 2 and a passive element 3 together with resin used to fill the gaps are put in a frame 4. On the surface of the resin are formed a wiring in which an organic polymer is used as a binder and metallic powders are used as a filler and an electrode terminal 7. Between the surfaces on which the electrode terminal 7 of the electronic circuit module 8 is formed and the electrode 10 of a printed wiring board 9 is formed, a conductive adhesive layer 13 in which metal particles 12 containing indium and silver is distributed is provided with an organic polymer 11 as a binder. The electrode terminal 7 and the electrode 9 are electrically connected to each other by the anisotropic conductivity in the direction of the thickness of the conductive adhesive layer 13.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an electronic circuit device, and particularly to an electronic circuit device in which an electronic circuit module is mounted on a printed wiring board.

(Prior Art) As a method of manufacturing an electronic circuit module incorporating semiconductor elements and passive elements, the method shown in FIG. 2 is known (
'plHarLSI 1interconnectio
nmethod utlizing polymeri
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Proc, 198B).

In this method, first, as shown in FIG. 2(a), electronic components such as semiconductor elements 1 and 2 and passive elements 3 such as chip capacitors are placed in a predetermined position within a frame 4 placed on a base substrate 6. The liquid resin 5 is then dripped into the gap between each element 1 to 3 and the frame 4 as shown in Figure (b), and after curing, the base is mounted as shown in Figure (C). Base material 6
This is a method in which wiring and electrode terminals 7 for connection between each element 1 to 3 are formed at the same time by peeling it off from the substrate and screen printing using a conductive paste, such as Ag paste, using an organic polymer as a binder. be. This method embeds components in resin and then wires them on the surface, making it easier to reduce the thickness of the parts. Also, by using multiple layers of wiring, it is possible to mount them at high density, making it possible to create ultra-small electronic circuit modules.

By the way, as a method of manufacturing a large-sized electronic circuit module by combining a plurality of such electronic circuit modules or other electronic circuit modules, there is a method of mounting the electronic circuit module on a printed wiring board. As a specific example of this method, solder or N
Using an anisotropically conductive adhesive sheet in which i-powder is dispersed, an electronic circuit module and a printed wiring board are bonded together by heating and pressure, and the electrode terminals of the electronic circuit module and electrodes on the printed wiring board are connected. There are possible ways.

However, this method cannot heat the solder or Ni to the melting point in order to prevent thermal deterioration of the resin in the electronic circuit module, so the anisotropic conductive adhesive sheet and the electrode terminals of the electronic circuit module and the electrodes on the printed wiring board What is
Continuity will be achieved through mere contact. For this reason, reliability at the bonding point is reduced due to springback of the binder resin in the electronic circuit module or the adhesive sheet.

(Problem to be Solved by the Invention) An electronic circuit device in which an electronic circuit module is mounted on a printed wiring board using an anisotropic conductive sheet in which solder or Ni powder is dispersed in a polymer. In this case, the anisotropically conductive adhesive sheet and the electrode terminals of the electronic circuit module and the electrodes on the printed wiring board will be electrically connected by mere contact, and the electrode terminals of the electronic circuit module and the electrodes on the printed wiring board will be electrically connected. There was a problem with the connection being unreliable.

An object of the present invention is to provide an electronic circuit device in which the connection between an electronic circuit module and a printed wiring board is highly reliable.

[Structure of the Invention] (Means for Solving the Problems) An electronic circuit device according to the present invention embeds a plurality of electronic components in a resin, and has electrode terminals mainly composed of an organic polymer and metal powder. A particulate metal containing an organic polymer and indium and silver is connected between the surface on which the electrode terminals of the electronic circuit module having the electronic circuit module are formed and the surface on which the electrodes are formed on the printed wiring board on which this electronic circuit module is mounted. The electrode terminals of the electronic circuit module and the electrodes on the printed wiring board are electrically connected to each other by a conductive adhesive layer consisting of the printed wiring board.

Here, the content of particulate metal in the conductive adhesive layer is 2
~30vol. % is preferred.

Moreover, it is desirable that the metal filler in the electrode terminal of the electronic circuit module is a silver filler.

(Function) In the electronic circuit device according to the present invention, since indium is contained in the granular metal in the conductive adhesive layer for connecting the electrode terminals of the electronic circuit module and the electrodes on the printed wiring board, electronic By heating and pressurizing the resin, which is the base material of the circuit module, to a temperature below the heat resistance temperature, the electronic circuit module and the printed wiring board are bonded, and the electrode terminals of the electronic circuit module and the electrodes on the printed wiring board are securely connected. Since the particulate metal contains silver, the stability of the connection between the particulate metal and the electrode terminal of the electronic circuit module is increased.

In addition, the content of granular metal in the conductive adhesive layer was set to 2 to 3
0vol. % range, the connection between the electrode terminals of the electronic circuit module and the electrodes on the printed wiring board is ensured, and there is no risk of continuity in the conductive adhesive layer in the plane direction, which eliminates the problem of short circuits between the electrodes. is avoided.

Furthermore, if silver filler, which is a constituent material of the granular metal in the conductive adhesive layer, is used as a metal filler in the electrode terminal of an electronic circuit module, the reliability of the electrical connection between the electrode terminal and the conductive adhesive layer can be improved. Further improvement.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of an electronic component device according to an embodiment of the present invention. In the same figure, the electronic circuit module 8 includes a semiconductor element 1.2 and a passive element 3 placed in a frame 4 together with a resin that fills the gap, as explained with reference to FIG.
Wiring and electrode terminals 7 are formed on the resin surface using an organic polymer as a binder and metal powder as a filler. Binder resins include thermosetting resins such as epoxy resins, phenolic resins, silicone resins, polyimide resins, acrylic resins, thermosetting 1-2 polybutadiene resins, or polycarbonate resins, polyvinyl chloride resins, polyethylene sulfide resins, polystyrene resins, etc. It is selected from thermoplastic resins, and these resins are used alone or in combination.

On the other hand, as the metal filler, gold, silver, copper, iron, nickel, tin, lead powder, etc. can be used, but silver or copper powder is suitable from the viewpoint of oxidation resistance and low cost. Furthermore, the viscosity may be adjusted by appropriately adding an antioxidant and a solvent.

The wiring and electrode terminals 7 of the electronic circuit module 8 are made of, for example, 10 parts by weight of epoxy resin, 80 parts by weight of silver powder with an average particle diameter of 5 μmφ, and 30 parts by weight of butyl acetate calpitol as a solvent.
Screen print the paste with mixed and adjusted weight parts, 1
It can be formed by curing by heat treatment at 20° C. for 30 minutes.

A plurality of electronic circuit modules 8 configured in this manner are mounted on a printed wiring board 9 to configure an electronic circuit device. As the printed wiring board 9, for example, a glass epoxy board, a paper phenol board, a polyimide board, a polyester board, a metal core printed wiring board, or a resin film printed with a conductive resin paint is used. Copper foil, silver paste,
Wiring layers and electrodes 10 made of copper paste, gold paste, or carbon paste are formed.

An organic polymer 11 is placed between the surface of the electronic circuit module 8 on which the electrode terminals 7 are formed and the surface of the printed wiring board 9 on which the electrodes 10 are formed. A conductive adhesive layer 13 in which particulate metal 12 containing silver is dispersed is provided, and the electrode terminal 7 and the electrode 9 are electrically connected by the anisotropic conductivity in the thickness direction of the conductive adhesive layer 13.

Here, as the organic polymer 11 in the conductive adhesive layer 13, epoxy resin, phenol resin, acrylic resin, polybutadiene resin, silicone resin, styrene resin, etc. can be used.

Further, the granular metal 12 may be any metal containing at least indium and silver, and may have an alloy composition with other metals such as tin, lead, antimony, bismuth, and cadmium.

Here, as an effect of including indium in the particulate metal 12, since the solidus temperature of the alloy of the particulate metal 12 can be lowered, the electronic circuit module 8 containing the resin 5
The granular metal 12 is melted by heating and pressurizing at a temperature that does not cause thermal deterioration, and the electrode terminals 7 of the electronic circuit module 8 and the electrodes 10 on the printed wiring board 9 can be connected. Further, as an effect of containing silver in the particulate metal 12, since silver easily diffuses into different metals, the reliability of the bonding becomes higher. In addition, in order to obtain these effects, the content of indium in the granular metal 12 is preferably in the range of 10 to 95 wt.%.

Furthermore, when silver filler is used for the electrode terminals 7 of the electronic circuit module 8, the same type of metal as the granular metal 12 is used, so that the electrical reliability of the bonding can be increased.

The content of the granular metal 12 in the conductive adhesive layer 13 consisting of the organic polymer 11 and the granular metal 12 is 2 to 30 vo.
l. % is preferred. The reason for this is that the content of granular metal is 2
vol. %, the distribution of the granular metal 12 becomes too sparse, and the distance between the electrode terminals 7 of the electronic circuit module 8 and the electrodes 10 on the printed wiring board 9 becomes narrow (and it becomes difficult to electrically connect the two). 30vol.
%, the granular metals 12 will come into contact with each other in the planar direction and electrical conductivity will occur in the conductive adhesive layer 13 even in the horizontal direction, and anisotropic conductivity will be lost and the electrode terminals 7 or between the electrodes will be electrically conductive. This is because the terminals 10 are short-circuited. Note that the average particle diameter of the granular metal 12 is suitably about 5 to 40 μmφ.

An embodiment of the method for manufacturing the above-mentioned electronic circuit device will be described. As the printed wiring board 9, a copper-clad lath epoxy board with a thickness of 0.1 mm was used, and as the conductive adhesive layer 13, indium/silver (with an average particle size of 25 μm) was used in a styrene-butadiene copolymer as the organic polymer 11. Weight ratio 90/1
0) granular metal 12 in 25 vol. % containing thickness o,
A sheet-like molded body of tmm was used. The conductive adhesive layer 13 made of this molded body is applied to the electrode terminal 7 of the electronic circuit module 8.
The temperature of the electronic circuit module 8 is set to 120°C, the temperature of the printed wiring board 9 is set to 70°C, and a pressure is applied. The electrode terminal 7 and the electrode 10 were connected by applying a pressure of I Kg/M 2 for 10 seconds.

The electronic circuit device thus obtained was heated to 90% at 60°C.
As a result of leaving it for 1000 hours in the high temperature and high humidity of R-H and examining the change in bonding resistance, the rate of change in bonding resistance was stable at 30% or less.

In the above example, the conductive adhesive layer 13 was molded into a sheet shape, but a suitable solvent,
For example, after diluting by adding acetone, toluene, butyl acetate calpitol, etc., mixing and adjusting the granular metal 12, and applying it to a predetermined position by printing or using a dispenser, the electronic circuit module 8 is applied under the same conditions as above. A similarly good connection was obtained even when bonding was performed using pressure and heat.

[Effects of the Invention] According to the present invention, granular metal is used in the conductive adhesive layer for bonding an electronic circuit module and a printed wiring board and for connecting electrode terminals of the electronic circuit module and electrodes on the printed wiring board. contains indium and silver, so the conductive adhesive layer can be reliably bonded to the electrode terminals of the electronic circuit module and the electrodes on the printed wiring board at temperatures below the heat resistance temperature of the resin that is the base material of the electronic circuit module. Moreover, the stability of the connection between the granular metal and the electrode terminal of the electronic circuit module is increased.

In addition, the content of granular metal in the conductive adhesive layer was set to 2 to 3
0vol. % range, the electrode terminals of the electronic circuit module and the electrodes on the printed wiring board can be reliably connected without causing short circuits between the electrode terminals or between the electrodes due to continuity of the conductive adhesive layer in the planar direction. becomes possible.

In addition, by using silver filler, which is the same kind of material as the granular metal constituent material in the conductive adhesive layer, as the metal filler in the electrode terminal of the electronic circuit module, the reliability of the connection between the electrode terminal and the conductive adhesive layer can be improved. can be further improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of an electronic circuit device according to the present invention, and FIG. 2 is a diagram showing a manufacturing process of the electronic circuit module in FIG. 1. 1.2...Semiconductor element, 3...Passive element, 4...
Frame body, 5... Resin, 6... Base material, 7... Electrode terminal, 8... Electronic circuit module, 9... Printed wiring board, 10... Electrode, 11... Organic polymer, 1
2... Particulate metal, 13... Conductive adhesive layer. Applicant's agent Patent attorney Takehiko Suzue

Claims (3)

[Claims] (1) An electronic circuit module having a printed wiring board, a plurality of electronic components embedded in a resin, and electrode terminals whose main components are an organic polymer and a metal filler, and the electrode terminals of this electronic circuit module. is provided between the surface on which the electrode is formed and the surface of the printed wiring board on which the electrode is formed, and is made of an organic polymer and a granular metal containing indium and silver,
An electronic circuit device comprising: a conductive adhesive layer that joins the electronic circuit module and the printed wiring board and connects electrode terminals of the electronic circuit module and electrodes on the printed wiring board. (2) The content of the particulate metal in the conductive adhesive layer is 2 to 30 vol. Claim 1 characterized in that
The electronic circuit device described. (3) Claim 1, wherein the metal filler in the electrode terminal of the electronic circuit module is a silver filler.
The electronic circuit device described.