JPS6140134B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for hermetically sealing a container for a semiconductor device.

Conventionally, as a seam weld type semiconductor device container, there is a semiconductor device container made by applying a metallized pattern to a ceramic substrate and brazing external leads and a round or square sealing frame. (Hereafter, the former will be referred to as a round seam weld case, and the latter will be referred to as a square seam weld case). These semiconductor device containers are sealed by using a rotary seam welder using parallel electrodes, placing a round or square cap on the sealing frame of the semiconductor device container, and rotating the semiconductor device container. However, electric resistance welding was performed on the tapered surface of the roller power source. However, the sealing of square seam welds has the disadvantage that the caps tend to shift because they are rotated for sealing, and welding defects around the corners tend to occur. That is, referring to FIG. 1 which describes a method of hermetically sealing a conventional rectangular seam weld case, FIGS. 1 a and b
As shown in the plan view and front view, after fixing the semiconductor device container 2 to the rotary table 1, aligning and placing the square cap 4 on the square seal frame 3, and turning on the switch, the roller electrode 5 will release air. After descending by the force of the cylinder and pressing down on the square cap 4, the rotary table 1 begins to rotate, and then a current is applied. Next, as shown in the plan view and front view of FIG. Although the electrode contacts and seals while moving completely, the contact area between the tapered surface of the electrode and the cap increases around the corners, resulting in lower contact resistance and insufficient melting, which may result in uneven melting on all sides or in the center of the cap. The problem was that excessive current flowed through the capacitor, causing cap burn. As mentioned above, with the conventional sealing method, there is no problem when sealing a round seam weld case with a rotary seam welder.
When sealing a rectangular seam-weld case, there is a drawback that the manufacturing yield and reliability of the product are reduced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for sealing a container for a semiconductor device that eliminates the above-mentioned drawbacks and has high reliability, high manufacturing yield, and high efficiency.

According to the present invention, electric resistance welding is performed by rotating the semiconductor container while bringing the outer diameter portions of a pair of cylindrical roller electrodes into contact with the side surfaces of the cap placed on the seal frame, and applying current between the two electrodes. A hermetic sealing method is obtained.

That is, in the present invention, a container for semiconductor devices equipped with a seal frame is placed on a rotating table, a cap is placed on the container, and a pair of roller electrodes are moved from the sides of the seal frame and the cap into contact with each other to rotate the container. In this method, a pair of vertically mounted cylindrical roller electrodes are moved by a spring toward the axis of a rotary table and come into contact with the side surface of the cap. Therefore, even if the container is rotated 360 degrees, the contact area on each side and corner remains constant.

The present invention will be described in detail below with reference to FIGS. 2 and 3. FIG. 2 shows a plan view and a side view of the sealing method of the present invention, and FIG. 3 shows a detailed enlarged view of a part thereof. Figure 2 shows the steps of the sealing method.
The structure of the present seam welder includes a pair of welding heads 26 centered around a rotary table 21, and a cylindrical roller electrode 29 is attached to the tip of the welding head with a vertical axis. The welding head 26 is equipped with a spring 27, and the receiving portion of the support rod 25 is movable. Also cap 2
A load 28 for fixing 7 is also provided. In FIGS. 1a and 1c, the semiconductor container 22 is placed on the rotating table 21 of the seam welder described above, and the cap 27 is opened.
When the switch is turned on after placing the cap, a load 28 for fixing the cap 27 is lowered onto the cap to prevent the cap from lifting up. Next, in conjunction with the load, the roller electrode 29 moves from left and right with the welding head 26 toward the side of the cap and the side of the seal ring, and when the load reaches a certain level, the rotary table 21 is rotated by a micro switch, and then the rotary table 21 is rotated with a low voltage and high current. When electricity is applied, the side surface of the cap and the side surface of the seal ring 29 are melted together, and the cap 27 and the seal ring 23 are welded together. FIG. 3 is a partially enlarged cross-sectional view for explaining the welding state described above. The seal ring 23 of the semiconductor container 22 is made by press-molding a metal plate of about 0.1 mm and brazing it with Ag-Cu. 0.1 for this seal ring 29
When a cap 27 with a thickness of about mm is placed and welded, the sides of the cap and the seal ring are in perpendicular contact with the roller electrode at any position when the container is rotated 360 degrees, so there is no uneven melting. Secondly, the heat generated due to the load for fixing the cap is absorbed, so there is no cap burning. or,
Since the seal ring is molded from a plate material, the wall 30 absorbs the distortion due to thermal expansion due to heat generated during sealing, so that the brazing part 31 does not receive it directly, which is advantageous for improving airtightness.

As described above, the present invention has major features in improving the manufacturing yield during sealing and the reliability of airtightness.

[Brief explanation of the drawing]

FIGS. 1a, b, c, and d show a plan view and a front view for explaining a conventional method of sealing a square seam-weld case. Figures 2a, b, c, and d show a plan view and a front view for explaining the hermetic sealing method according to the present invention. FIG. 3 is a partially enlarged sectional view when sealing is performed according to the present invention. 1, 21... Rotating table, 2, 22... Semiconductor container, 3, 23... Seal ring, 4, 24... Cap, 5, 29... Roller electrode, 25... Support rod, 26... Welding Head, 27...Spring, 28...Load, 30...Wall.

Claims (1)

[Claims] 1. Place a semiconductor device container equipped with a seal frame on a rotary table, place a cap on the container, and rotate the roller electrode relative to the container along with the seal frame of the container. In the method for hermetically sealing the container and the cap, the roller electrode is a cylindrical roller electrode, and the axis of rotation is substantially perpendicular.