JP2710987B2 - Cap warp straightening method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for correcting warpage of a cap generated during the manufacture of a cap used for a semiconductor device or the like.

(Prior Art) Some semiconductor devices are provided with a semiconductor chip mounted on a package and hermetically sealed with a metal cap on a semiconductor chip mounting portion.

There are various types of caps used for this hermetic sealing, such as a flat cap, but as shown in FIG. 2, the plane shape of the central portion corresponding to the semiconductor chip mounting portion is raised in a rectangular shape. In addition, there is a dish-shaped cap having a shallow cross-sectional shape whose peripheral edge is also formed as a rectangular flat flange. The cap having the raised portion is manufactured by drawing a metal plate.

(Problems to be Solved by the Invention) However, in the cap manufactured by the drawing process described above, when the drawing process is performed, the processing strain is concentrated on the four corners of the raised portion, so that the stress due to the strain acts on the flange. Then, the cap is warped. For example, if the outer shape of the cap is 25 mm square and the plate thickness is 0.2 mm, the warpage generated after drawing is about 150 to 350 μm, and the cap cannot be used as it is.

Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to correct the warpage of a cap manufactured by drawing, which can effectively correct the warpage generated during drawing. It seeks to provide a way.

(Means for Solving the Problems) The present invention has the following configuration to achieve the above object.

That is, a metal plate is drawn to form a ridge in which a planar shape is raised in a rectangular shape, and a cap provided with a rectangular flange at a peripheral edge of the ridge is manufactured. By hit-forming (pressing) the corners of the raised portion from above the raised portion, distortion generated in the raised portion at the time of drawing is alleviated, and warpage of the flange at the peripheral portion is eliminated.

(Operation) After the metal plate is drawn, the corners of the raised portions of the cap are hit-formed, so that the distortion of the corners of the raised portions can be alleviated, and the warpage of the flange portion at the peripheral edge can be corrected.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an explanatory view for explaining the method of the present invention, in which 10 is a cap corrected by the method of the present invention, and 12 is a punch used for the correction.

The overall shape of the cap 10 is rectangular, and a raised portion 12 is formed at the center thereof. The cap 10 is obtained by drawing a metal plate, and the protruding portion 12 protrudes in a rectangular shape at the center of the cap 10. A rectangular flange 14 is formed at the periphery of the raised portion 12. FIG. 2 shows a state in which the cap 10 is bonded to the package. As shown in FIG.
Is hermetically joined to the periphery of the upper end of the package by soldering or the like. The cross-sectional shape of the cap 10 is a shallow dish shape as shown in the figure.

As shown in FIG. 3, distortion of the cap after drawing is concentrated on the drawn portions at the four corners of the raised portion 12, and as a result,
Warpage occurs in the direction in which the edge of 14 approaches the ridge 12 side.

In FIG. 1, reference numeral 16 denotes a punch used to eliminate the warpage of the cap, and small projections projecting downward at four corners on the lower surface of the punch 16 corresponding to the four corners of the raised portion 12.
18 will be provided.

The positions of the four corners of the raised portion 12 of the cap after drawing and the position of the small projection 18 of the punch 16 are aligned, and when the punch 16 hits from above the raised portion 12, the raised portion 12 is formed.
And the warp of the flange 14 is corrected, and a cap whose warp has been corrected like the cap 10 shown in FIG. 1 is obtained.

In the figure, reference numeral 20 denotes indents (dents) formed by the small projections 18 hitting the four corners of the raised portion 12.

According to the method of correcting the warpage by hit-forming the raised portion 12 as described above, for example, in the case of the above-mentioned cap, the warpage of the corrected cap could be corrected to about 30 to 40 μm.

As described above, according to the method of hit-forming the raised portion, the warpage of the cap can be corrected extremely easily. This is because, by pressing the four corners of the raised portion 12 where distortion is most concentrated by drawing, the distortion of the raised portion 12 can be effectively reduced, and the distortion of the raised portion 12 by the punch 16 is corrected. The effect extends to the flange 14 at the peripheral portion, so that an overall effective warp correction is performed.

Also, in the above-described correction method, the punch 16 that hits the form directly hits only the raised portion 12 and
Since it does not hit directly, there is no risk of damaging the flange 14 which is the joint surface of the cap, and a suitable joint surface can be obtained.

FIG. 2 shows a state in which the cap 10 is bonded to the package and hermetically sealed. The cap 10 can be sealed more accurately because the warpage of the cap 10 is largely corrected.

Note that even in the case of a cap having an opening for heat sink bonding or the like at the center of the raised portion, the warpage during drawing can be corrected in the same manner as described above.

As described above, the present invention has been described variously with reference to the preferred embodiments. However, the present invention is not limited to these embodiments, but can be applied to various types of semiconductor devices in the same manner. It goes without saying that many modifications can be made without departing from the scope of the present invention.

(Effects of the Invention) As described above, according to the method for correcting the warpage of the cap according to the present invention, the corner of the raised portion of the cap is hit-formed to thereby extremely effectively correct the warpage of the cap caused by the drawing process. can do. In addition, the method according to the present invention is a simple method of hit-forming the raised portion of the cap, and thus has a remarkable effect such that the correction work can be easily performed.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing the method of the present invention, FIG. 2 is an explanatory view showing a state where the cap is joined to a package, and FIG. 3 is an explanatory view showing the warpage of the cap after drawing. 10 ... Cap, 12 ... Protrusion 14 ... Flange, 16 ... Punch, 18 ... Small protrusion, 20 ... Indentation.

Claims (1)

(57) [Claims] In producing a cap having a rectangular shape in a planar shape by drawing a metal plate and a cap provided with a rectangular flange at a peripheral edge of the projecting portion, the drawing process is performed. After that, the corner of the raised portion is hit-formed from above the raised portion, thereby relaxing the distortion generated in the raised portion during drawing and eliminating the warpage of the flange at the peripheral portion. Straightening method.