JPS59198728A - Fitting of electronic component parts - Google Patents

Abstract

PURPOSE:To enable to fit an electronic parts at the low temperature of the degree of 150 deg.C, and moreover regardless of a substrate material and a wiring material by a method wherein the electronic parts and the substrate are connected using a heat-sealing agent mixed with electrically-conductive particles. CONSTITUTION:An LSI wafer 7 furnished with Al pads 4 is heated at the degree of 150 deg.C, and a heat-sealing agent 5 is coated on the surface thereof at the degree of 20-50mum using a roller. Then a mask 8 formed by perforating the parts to face to the Al pads 4 is put on the coated heat-sealing agent 5, and after Ag powder 6 is scattered in the perforations thereof, heating is applied to make the Ag powder 6 to be settled. The wafer is cut at the parts shown with arrow marks to obtain LSI chips 3 adhered with the heat-sealing agent 5 and formed with the concentrated Ag powder at the parts corresponding to the Al pads 4. The LSI chip 3 obtained in such a manner is made to come in contact with the wiring 2 of a substrate 1 placing the heat-sealing agent 5 down, and a soldering iron heated at 150 deg.C is pressed by pressure of 20kg/cm<2> from the upper part of the LSI chip 3 to attain bonding.

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a method of attaching electronic components to a board.

<Prior art> Conventionally proposed general methods for attaching an electronic component (LSI) and a board include, for example, a bonding method using solder bumps and a bonding method using Au bumps, but the former is soldered at approximately 250°C. Since the method must be heated to a high temperature, it has the problem of adversely affecting electronic components and boards, and it also has the disadvantage that it cannot be applied to circuit boards wired with materials that cannot be soldered, such as carbon. Further, in the latter case as well, there were problems in that it was necessary to heat the bonding process to about 450° C. and that the electrode pads on the substrate had to be previously plated with Sn.

Purpose> The present invention was made in view of such conventional problems, and
The present invention provides a new method for attaching electronic components that allows electronic components to be bonded at low temperatures regardless of substrate material or wiring material.

<Example> The wooden invention will be explained in detail below based on the figures.

FIG. 1 is a diagram showing electronic components mounted on a board by the method of the present invention.

In the figure, 1 is a substrate, 2 is wiring on the substrate, and 3 is an LSI chip with Af pads 4 provided on terminal portions. Also,
Reference numeral 5 indicates a heat sealing agent (or hot tart adhesive), and the substrate 1 and the LSI chip 3 are bonded and layered by this heat sealing agent. This heat sealing agent contains conductive particles 6, such as Ag, A 11% C%, in advance.
Cu-, Ni powder is mixed in, and these particles are concentrated between the Al pad 4 of the LSI chip 4 and the wiring 2 of the substrate at 6t/'i, so that the LSI chip 3 is heated. It is attached to the substrate 1 with a sealant 5, and the chip terminal and the substrate wiring are electrically connected via conductive particles 6.

FIG. 2 shows the installation procedure using the heat sealing agent, and will be explained in more detail with reference to this figure.

Don't choose, A? 150 LSI wafers 7 equipped with pads 4
Heat to about ℃ (Figure ■) and apply heat sealant 5 on the surface.
Coat with a roller to a thickness of about 20 to 50μ (Figure ■)
. Next, a mask 8 made by perforating the part facing the Al pad 4 is placed on top of the coated heat sealant 5, and after scattering Ag powder 6 into the perforations (Fig. ■), the Ag powder is heated. 6 is allowed to settle (Figure @). Then, the LSI chip 3 is cut in the direction of the arrow (Fig. ■), and the LSI chip 3 is coated with a heat sealing agent 5 made of concentrated Ag powder in the portion corresponding to the l' pad 4 (Fig. ■).

The LSI chip 3 thus obtained is brought into contact with the wiring 2 of the substrate 1 with the heat sealant 5 facing down.

A soldering iron heated to 150°C is placed over the LSI chip 3.
Q Kq/cl Pressurize and bond.

According to this mounting method, since the heat sealant is a so-called resin adhesive, electronic components can be mounted at low temperatures regardless of the board material or wiring material. Because the particles are mixed in, it is possible to electrically connect electronic component terminals and board wiring.

As described above, since the method of the present invention uses a heat sealing agent mixed with conductive particles to bond electronic components and a board, it can be bonded at a low temperature of about 150"C, and can be applied to board materials and wiring materials. Electronic components can be installed regardless of the

Therefore, it is possible to attach electronic components to any substrate, and it is possible to perform highly reliable bonding by eliminating the adverse effects of heat.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a state in which an electronic component and a board are attached by the method of the present invention, and Figures 2 to 2 are diagrams explaining the attachment procedure. 1 is a substrate, 2 is a wiring, 3 is an LSI chip, 4 is an Al pad, 5 is a heat sealing agent, and 6 is a conductive particle. Agent Patent attorney Aihiko Fukushi (and 2 other people) 1st person;

Claims (1)

[Scope of Claims] 1. A method for attaching electronic components, which comprises bonding electronic components onto a substrate using a heat sealing agent mixed with conductive particles. 2. The method of attaching an electronic component according to claim 1, wherein the conductive particles in the heat sealing agent are concentrated between the electronic component and the terminals of the board.