JPH03220753A - Packaging of electronic parts - Google Patents

Abstract

PURPOSE:To prevent generation of pin holes in the connection part and lift of a cap for reducing work labor by performing a process of sticking the cap to a base at an equal atmospheric temperature to a thermal hardening temperature of an adhesive. CONSTITUTION:A cap 3, to which a thermal hardening adhesive 4 such as thermal hardening resin and glass paste is applied, it put on a base 2 loaded with an element 1 of electronic parts to stick the cap 3 to the base 2. In this case, in an atmospheric temperature of the same degree with the thermocuring temperature of the used adhesive 4, the cap 3 is stuck to the base 2 loaded with the element 1 of electronic parts, later, the adhesive 4 is cured at a prescribed thermocuring temperature to fix the cap 3 to the base 2 for sealing the element 1 of electronic parts inside a cavity 5 formed by the cap 3 and the base 2. Thereby, generation of pin holes in the adhesive can be prevented, and the thickness of the adhesive is prevented from becoming ununiform.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for hermetically sealing an electronic component within a package configured by bonding a cap and a base.

[Background Art] When an electronic component element is hermetically sealed in a package having a cavity inside, packaging is conventionally performed as follows.

First, at room temperature, a cap coated with a resin such as epoxy resin or a thermosetting adhesive such as glass paste is placed on top of the base on which the electronic component element is mounted. Thereafter, the package containing this electronic component element is moved and placed in a thermosetting bath, and is heated to a temperature of, for example, 150°C in the thermosetting bath.
The adhesive is heated and cured at a temperature of ~200°C, and the electronic component element is sealed within the package consisting of the cap and the base.

However, in the step of heating and curing the thermosetting adhesive in a thermosetting tank, the thermosetting adhesive is once softened before hardening, and the air sealed inside the package is thermally expanded. Therefore, as shown in FIG. 4, the pressure inside the package 6 made up of the cap 3 and the base 2 is higher than the outside (in the figure, the magnitude of the pressure is roughly represented by the length of the arrow). ), the air inside tries to escape to the outside, causing pinholes in the adhesive 4, or the cap 3 lifting and tilting due to the internal pressure, causing the thickness of the adhesive 4 to become uneven, causing the adhesive 4 to leak in some parts. There was a problem in that the reliability of manufactured electronic components decreased as the thickness of the electronic components became thinner. This problem,
This was particularly noticeable in the case of packages with large internal cavities, such as LSI packages.

In order to eliminate this drawback, conventionally, the cap 3 and the base 2 are held between each electronic component using a holding jig such as a clip, and the electronic component is thermally cured while applying a load W to the adhesive 4. It was in a tank.

[Problems to be Solved by the Invention] However, the conventional method of holding electronic components one by one between holding jigs such as clips and placing them in a thermosetting bath requires a large number of holding jigs. This requires complicated work to attach and remove the presser jig to each package, which requires a large amount of work effort.

The present invention has been made in view of the drawbacks of the conventional examples described above, and its purpose is to eliminate the occurrence of pinholes and lifting of caps at the adhesive part during the heat curing process of the adhesive by a simple operation. The purpose is to prevent such problems and reduce work effort.

[Means for Solving the Problems] For this reason, the electronic component packaging method of the present invention applies a thermosetting adhesive to a base on which an electronic component element is mounted at an ambient temperature comparable to the heating curing temperature of the adhesive used. The cap is bonded to the cap by the above method, and then the cap and the base are fixed by curing the adhesive at a predetermined heat curing temperature, and the electronic component element is sealed in the cavity formed by the cap and the base. It is said that

[Function] In the present invention, the step of bonding the cap to the base is carried out at an ambient temperature similar to the heating curing temperature of the adhesive, so the package is placed in a thermosetting bath or the like and the adhesive is applied. When heated and cured, the balance between internal and external air pressure is maintained. This prevents pinholes from forming in the adhesive due to high pressure inside the package and air trying to escape to the outside, and also prevents the cap from floating and tilting. can be made uniform.

Moreover, since the bonding work between the cap and the base is simply carried out at an ambient temperature similar to the heat curing temperature of the adhesive, there is no need for holding jigs such as clips, and this method is more effective than methods that use holding jigs. The work effort can be significantly reduced.

[Example] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

The package 6 is composed of a base 2 made of ceramic fired product or the like and a cap 3. The base 2 is provided with a surface electrode (not shown), and as shown in FIG. 1(a), an electronic component element 1 such as an LSI is mounted on the upper surface of the base 2. 1 and the surface electrode is wire 7
bonded by. A cap 8 coated with a thermosetting adhesive 4 such as a thermosetting resin or glass paste is placed on the base 2 on which the electronic component element 1 is mounted, and the cap 3 and the base 2 are bonded together. This bonding process is carried out at an ambient temperature (e.g., 150° C.
As shown in FIG. 1(b), for example, the base 2 is placed on a heating plate 8 and the cap 3 is bonded to the base 2 in a heated state. After this, cap 3 and base 2
The packaged electronic component 9 is placed in a thermosetting bath (not shown), where it is kept at the heating curing temperature of the adhesive 4 (for example, 150 to 200°C), and the adhesive 4 The cap 3 and the base 2 are fixed together by heating and hardening, and the electronic component element 1 is placed in the cavity 5 of the package 6.
is hermetically sealed.

When transferring the electronic component 9 to the thermosetting tank, if the electronic component 9 is immediately put into the thermosetting tank from above the heating platen 8, the temperature change between the bonding process and the heating curing process is small, so the air inside the package e is
Only small thermal expansion or contraction occurs, as shown in Figure 1 (C).
As shown in the figure, the air pressure is balanced between the inside and outside of the package 6. Furthermore, even if it takes some time to move from the heating platen 8 to the thermosetting bath and the temperature of the package 6 drops during the transfer, when the electronic component 9 is placed in the thermosetting bath, the temperature inside the package 6 will change again. The air expands thermally, and no large pressure difference occurs between the inside and outside of the package 6 as shown in FIG. 1(c). Therefore, even if the adhesive softens in the thermosetting tank, the internal air pressure does not cause pinholes in the adhesive 4, and the electronic component element 1 can be reliably sealed.

Further, the cap 3 is not lifted by internal pressure and the adhesive 4 does not become thinner on one side. Therefore,
The thickness of the adhesive 4 becomes uniform, the assembled shape of the package 6 becomes stable, and the sealability of the package 6 becomes good, so that a highly reliable package for electronic components can be obtained. Incidentally, this method is particularly effective when the volume of the cavity 5 within the package 6 is 100 mm' or less.

Note that if it takes some time to put the base 2 and cap 3 into the thermosetting tank after bonding them on the heating plate 8,
The air inside may shrink due to heat, lowering the internal pressure. In this case, as shown in FIG. 2, the adhesive 4 may be pushed into the inside of the package 6 during the process movement, and conversely, pinholes may occur in the adhesive 4 from the outside. In such a case, pinholes can be prevented by limiting the ratio of the length of the side of the base 2 to the thickness (or width of the adhesive surface) Q of the cap 3 to L/Q<15. I was able to do that.

Note that the material and shape of the package are not limited to those shown in the above embodiments. For example, as shown in FIG. 3, a plate-shaped cap 3 is glued onto a container-shaped base 2, The electronic component element 1 may be sealed inside the package 6.

[Effects of the Invention] According to the present invention, when the package is placed in a thermosetting bath or the like and the thermosetting adhesive is heated and cured, the balance between the pressure inside and outside the package can be maintained.

This prevents pinholes from forming in the adhesive due to the air inside the package trying to escape to the outside, and also prevents the cap from floating and tilting due to internal pressure, resulting in uneven thickness of the adhesive. This makes it possible to improve the reliability of packaged electronic components and to stabilize the product shape.

Moreover, since the cap and base are bonded together at an ambient temperature similar to the heat curing temperature of the adhesive,
It is possible to prevent the occurrence of pinholes etc. with a simple operation, eliminate the need for holding jigs such as clips, which have been used in the past, reduce the manufacturing cost of electronic components, and replace the conventional method using clips etc. In comparison, the work effort can be significantly reduced.

[Brief explanation of drawings]

FIGS. 1(a), (b), and (c) are cross-sectional views showing one embodiment of the present invention, FIG.
FIG. 3 is a sectional view showing another shape of the package, FIG. 4 is an explanatory view illustrating the drawbacks of the conventional packaging method, and FIG. 5 is a sectional view illustrating another conventional example. 1...Electronic component element 2...Base 3...Cap 4...Adhesive 5...Cavity

Claims (1)

[Claims] (1) At an ambient temperature similar to the heat curing temperature of the adhesive used, the cap is bonded to the base on which the electronic component element is mounted using a thermosetting adhesive, and then the adhesive is heated to a predetermined heat curing temperature. A method for packaging electronic components, characterized in that the cap and the base are fixed together by curing, and the electronic component element is sealed in a cavity formed by the cap and the base.