JPS59910B2 - magnetic bubble memory package - Google Patents

Abstract

PURPOSE:To avoid the bubrle generation even with the thermal treatment applied by filling up the area between the bubble chip and the substrate via a low-viscosity adhesive featuring a high fluidity and quick drying performance, and thus to reduce the working time as well as the production cost.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic bubble memory package, and particularly to a magnetic bubble memory package in which a magnetic bubble chip is fixed to a substrate by die bonding.

When assembling a magnetic bubble device, packaging is performed by bonding a substrate and a magnetic bubble chip using a die bonding method in order to ensure reliable positioning between components and reliability of wiring.

Furthermore, the entire substrate to which the magnetic bubble chip is die-bonded is coated with resin in order to prevent oxidation, corrosion, dust, etc. from adhering to the magnetic bubble chip and the wiring parts on the board due to exposure to the air. . However, when coating the resin, the conventional adhesive used to bond the magnetic bubble chip to the substrate changes the magnetic properties of the magnetic bubble chip, as will be explained later, and also has a negative impact on other packaging processes. affect

In another patent application, the applicant has proposed that a magnetic bubble chip can be reliably fixed to a substrate without changing the magnetic properties of the magnetic bubble chip and without adversely affecting other packaging steps. Therefore, we proposed the use of insulating and elastic silicone adhesive as an adhesive.

However, in this method, there is a limit to the amount of silicone adhesive that can adhere between the substrate and the bubble chip, so a gap is created between the substrate and the chip, which creates a cavity inside when the exterior is coated with silicone resin. It gets old and remains.

As a result, when the silicone coating agent is heat-treated, the bubbles sometimes move to the outer surface and burst, exposing the bonding portion and the like. The present invention seeks to provide an improved bubble memory package that prevents the generation of such bubbles.

This will be explained below with reference to the drawings. FIG. 1 shows a bubble memory package according to the present invention. In the figure, 1 is a substrate made of copper, ceramic or glass epoxy resin, 2 is a magnetic bubble chip, and 3 is an Au wire printed on the substrate 1. A lead wire 5 made of aluminum electrically connects an output terminal of a detector etc. provided in the magnetic bubble chip 2 and an amplifier (not shown) provided on the substrate 1. A silicone adhesive such as SE1700 is bonded between the substrate 1 and the magnetic bubble chip 2, and 6 is a silicone resin for shielding the surface of the substrate 1 from the outside air.

In addition, the peripheral circuitry essential to the magnetic bubble device, the magnetic bias circuit, the drive coil, and other peripheral components are omitted in the figure. According to the conventional package, first, the magnetic bubble chip 2 is die-bonded to a predetermined position on the substrate 1 using silicone adhesive 5, and then the input/output terminals of the magnetic bubble chip 2 and the external lead wire 3 are connected with the lead wire 4. ,
Afterwards, cover the whole thing with silicone resin.

Coating with silicone resin is not particularly necessary in a laboratory setting, but it is indispensable in order to prevent influences from the external environment and increase reliability during commercialization. At this time, as mentioned above, a gap (corresponding to the part indicated by 7) is created between the chip 2 and the substrate 1, which becomes bubbles during the heat treatment and ruptures near the outer surface, exposing the lead wires 5 and damaging the protective coating 6. It makes the work meaningless. Therefore, according to the present invention, before coating the silicone resin 6, a cyan adhesive 7 such as Aron Alpha, which has low viscosity, fluidity, and drying properties, is poured into the gap between the substrate 1 and the chip 2.

In practice, for example, using a nozzle, etc., apply the adhesive 7 from all sides.
can be poured into it. By applying the protective coating 6 after filling the adhesive 7, the formation of air bubbles is completely prevented. Adhesive generally has to cause distortion to the chip, but in the present invention it can be ignored since most of the distortion is covered with elastic silicone adhesive. According to the present invention, even if a predetermined heat treatment is performed after coating the silicone sheath 6, no bubbles are generated, so the above-mentioned drawbacks are completely eliminated. Furthermore, since a defoaming step is no longer necessary, working time and costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is an illustrative view of a bubble memory package according to the present invention. 1...Substrate, 2...Bubble chip, 4
...Lead wire, 5...Silicon adhesive, 6...Silicon coating, 7...
...Cyan adhesive.

Claims (1)

[Claims] 1. Fix the bubble chip to the substrate with an insulating and elastic silicone adhesive, and fill the gap between the bubble chip and the substrate with a low-viscosity, fluid, and quick-drying adhesive, and cover the bubble chip surface and adhesive area with silicone. A magnetic bubble memory package with an exterior coating made of resin.