JPS6032766Y2 - LSI chip protection cap - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a cap for protecting LSI chips.

Conventionally, in a plug-in board (hereinafter simply referred to as a board) made by brazing pins onto a ceramic board, after mounting an LSI chip on the board, the following 6. One method is to use a box-shaped protective cap 1 with one side open as shown in Figure 1.
0 is used.

An adhesive such as glass or resin is applied to the end surface 11 of the opening of the protective cap 10.

Then, as shown in FIG. 2, the L
The end face 11 is attached to the substrate 14 through the attachment agent in a high-temperature atmosphere so as to cover the SI chip 15, and the L
The SI chip is kept airtight by shielding it from the outside air.

However, as shown in FIG.
Depending on the position of the opening, the outer edge 12 of the opening may approach the pin 16 and the soldering of the pin 16 may ride on the fillet portion 17. In such a case, the opening end surface 11 may not touch the substrate 14. LSI chip 1 cannot be brought into close contact.
Outside air enters into 5, causing a serious defect in reliability.

Therefore, in order to overcome the above defects, the protective cap 1
Although the cap 10 is prevented from coming close to the pins 16 of the board 14 by using a mounting jig of 0.0, there is a drawback that the number of assembly steps increases.

Another method for overcoming the above defects is to provide a seal ring 18 on the substrate 14 and weld a lid 19 made of metal such as Kovar to protect the LSI chip 15, as shown in FIG. However, the disadvantage is that the substrate 14 becomes expensive, resulting in higher costs.

The purpose of this invention is to create an inexpensive and highly reliable plug-in LSI.
An object of the present invention is to provide a cap for protecting an LSI chip for realizing a package.

In order to achieve this purpose, the LSI chip protection cap according to the present invention has a pin brazed at a position higher than the fillet part than the end face of the opening part, and a width wider than the width of the fillet part from the outer edge of the opening part. It is characterized by a flange that protrudes from the outer wall.

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 5 shows an example of a 6-chip protective cap according to the present invention, which differs from the conventional example in that the protective cap 20 has a flange 22.

That is, the flange 22 protrudes outward from the outer periphery of the bottom 23 of the cap 20, but it protrudes from the outer wall 24 of the opening by a width W at a position that is a height H from the opening end surface 21 that is bonded to a substrate (not shown). As shown in FIG. 6, if the height of the fillet portion 17 is the height of the brazing of the pin 16 at the base on the substrate 14 side, and the width is W, then the relationship between these is expressed by the following equation.

H>h W>w Because of the above configuration, the outer edge of the flange 22 is connected to the pin 16.
Even in the case where the protective cap 20 contacts the fillet portion 17, the opening end surface 21 of the protective cap 20 is reliably bonded to the substrate 14 without running onto the fillet portion 17 during brazing.

Therefore, by extending the flange to the LSI chip protection cap, it is possible to eliminate the need for mounting jigs.
Plug-in type that allows complete adhesion and sealing and is inexpensive
■We can provide packages.

Another embodiment of the invention is shown in FIG.

In this case, the shape of the flange is different from the above embodiment, and has a shape in which the outer edge 31A of the opening end face 31 and the upper outer edge 32A of the flange 32 are connected at the upper opening position shown in the figure.

However, even in this case, the height H1 width W of the flange 32
The dimensions are the same as in the previous embodiment in that the brazing must be larger than the height h1 width W (see FIG. 6) of the fillet portion.

The shape of this embodiment is extremely advantageous when the LSI chip protection cap is made of a material such as ceramic and integrally molded.

As described above, in the present invention, since the cap is provided with a flange, the bonding surface of the cap does not ride on the fillet portion during brazing at the base of the pin, and can be completely bonded to the substrate surface.

Therefore, the LSI housed inside can be completely protected.

[Brief explanation of drawings]

FIG. 1 is a partially broken perspective view showing an example of a conventional LSI protection cap, and FIGS. 2 and 3 are partially broken side views and illustrating a state in which the conventional example is adhered to a substrate. 4 is a partially cutaway side view showing a state in which a seal ring is attached to the board, FIG. 5 is a partially cutaway perspective view showing an example of an LSI protection cap according to the present invention, and FIG. 7 is an enlarged partially broken side view for explaining the effects of this embodiment, and FIG. 7 is a partially broken perspective view showing another embodiment of the present invention. In the figure, 11, 31... end face of the opening, 14
...Plug-in board, 15...-LSI
Chip, 16...Zen, 17...Brazing is at fillet part, 22.32...Flange, H
... Flange height, W ... Flange width, h ... Fillet height, W ... Inside fillet.

Claims (1)

[Scope of utility model registration request] In an LSI chip protection cap, which accommodates an LSI chip mounted between pins brazed to a plug-in board, and has an end face of an opening mounted on the plug-in board to seal the LSI chip. 6. A flange having a width wider than the width of the fillet portion protrudes from the outer edge of the opening portion from the outer edge of the opening portion, and the pin is brazed at a position higher than the fillet portion from the end surface of the opening portion.
■Cap for chip protection.