JP2763417B2 - Manufacturing method of semiconductor device storage package - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device housing package for housing a semiconductor integrated circuit device.

[0002]

2. Description of the Related Art In recent years, as information processing apparatuses such as computers have become higher in performance and higher in speed, semiconductor elements used therein have rapidly increased in density and integration. For this reason, the heat generation amount per unit area and unit volume of a semiconductor element is increasing, and it is important to efficiently remove the heat generated by the semiconductor element in order to operate the semiconductor element normally and stably. It has become a challenge.

Conventionally, a package for accommodating such a semiconductor element and effectively removing the heat generated by the semiconductor element is provided on a heat dissipation base 22 as shown in FIG.
And a ceramic frame 23 and a lid 24.

The heat dissipation base 22 is made of a material having good thermal conductivity, such as a copper-tungsten alloy, and has a convex semiconductor element mounting portion A on which a semiconductor element 25 is mounted substantially at the center of the upper surface. The semiconductor element mounting portion A has a semiconductor element 25
Are attached via an adhesive.

The heat radiating base 22 functions to absorb the heat generated by the semiconductor element 25 into the heat radiating base 22 and release the absorbed heat to the atmosphere, thereby efficiently removing the heat generated by the semiconductor element 25. .

The heat dissipating body 22 has a ceramic frame 23 surrounding the semiconductor mounting portion A at the outer peripheral end of the upper surface thereof.
Are joined via a brazing material such as silver brazing, and a recess for accommodating the semiconductor element 25 is formed by the radiator 22 and the ceramic frame 23.

The ceramic frame 23 is made of ceramics such as alumina ceramics and has a rectangular through hole B having a flange C on the lower surface at a substantially central portion thereof. A metallized wiring layer 26 made of a high melting point metal powder such as tungsten or molybdenum is provided from the upper surface to the upper surface of the ceramic frame 23.

An external lead pin 27 for electrically connecting the semiconductor element 25 to an external electric circuit is attached to an upper surface of the ceramic frame 22 of the metallized wiring layer 26, and a semiconductor is mounted to an upper surface of the flange portion C. The electrodes of the element 25 are electrically connected via the bonding wires 28.

On the upper surface of the ceramic frame 23, a cover 24 is attached via a sealing material such as glass so as to cover the through hole B. The semiconductor device 25 as a final product is obtained by hermetically sealing the semiconductor element 25 inside a container made of the following.

In such a conventional package for accommodating a semiconductor element, the ceramic frame 23 is usually manufactured by the following method.

That is, first, as shown in FIG. 3A, a first frame-shaped ceramic green sheet having a through hole in the center and a plurality of wiring conductor layers 26a to be metallized wiring layers on the upper surface. 23a and the first frame-shaped ceramic green sheet 23a have through holes slightly larger than
In addition, a second frame-shaped ceramic green sheet 23b having a wiring conductor layer 26b which penetrates from the upper surface to the lower surface and becomes a metallized wiring layer is prepared.

Next, a second frame-shaped ceramic green sheet 23b is laminated on the first frame-shaped ceramic green sheet 23a, and this is pressed from above and below to obtain a ceramic green sheet laminate.

Finally, the ceramic green sheet laminate is fired at a high temperature in a reducing atmosphere, so that each of the frame-shaped ceramic green sheets 23a and 23b and the wiring conductor layers 26a and
3b, the ceramic frame 23 having a through hole B having a flange C on the lower surface side and a metallized wiring layer 26 extending from the upper surface of the flange C to the upper surface as shown in FIG. 3 (b). Is produced.

[0014]

However, according to the conventional method for manufacturing a package for housing a semiconductor element,
When firing the ceramic green sheet laminate, the tip of the flange C is free and easily deformed.
Deformation occurs such that the flange portion C of the ceramic frame 23 is warped upward due to internal residual stress due to a difference in pressurizing pressure when obtaining a laminate, a difference in firing shrinkage of each ceramic green sheet, and the like. . When such deformation occurs, it becomes impossible to accurately and firmly connect the bonding wire 28 for connecting the semiconductor element 25 to the metallized wiring layer 26, and the semiconductor element 25 housed inside is not connected to an external electric circuit. It is impossible to connect accurately and securely.

The ceramic frame 23 and the heat dissipation base 22
With the ceramic frame 23
Cannot be firmly bonded to the heat radiating base 22, and when an external force or thermal stress due to heat generated by the semiconductor element 25 is applied to the heat radiating base 22, the ceramic frame 2 is
3 is peeled off from the heat radiating base 22, and a gap is generated between the ceramic frame 23 and the heat radiating base 22, so that the airtightness in the package cannot be maintained, and the semiconductor element 2 housed inside
5 has a drawback that it cannot be operated stably for a long period of time.

[0016]

According to the present invention, there is provided a semiconductor element housing package comprising a ceramic frame joined to an upper surface of a heat dissipation base having a semiconductor element mounting portion so as to surround the semiconductor element mounting portion. The ceramic frame is manufactured by the following steps (1) to (3).

(1) a step of preparing a flat ceramic green sheet to be a dummy layer and a frame-shaped ceramic green sheet to be a ceramic frame; and (2) a step of providing a flat ceramic green sheet to be a dummy layer. A step of laminating frame-shaped ceramic green sheets to be a ceramic frame, and firing these to obtain a ceramic sintered body in which the dummy layer and the ceramic frame are integrated,
(3) Step of grinding and removing the dummy layer of the ceramic sintered body to obtain a ceramic frame

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a ceramic frame of a package for housing a semiconductor element according to the present invention will be described in detail with reference to the embodiment shown in FIG.

First, as shown in FIG. 1A, a flat ceramic green sheet 1a to be a dummy layer and first and second frame-shaped ceramic green sheets 1b and 1c to be a ceramic frame are prepared. .

The ceramic green sheet 1a serving as the dummy layer and the first and second frame-shaped ceramic green sheets serving as the ceramic frame are made of, for example, alumina ceramics, and are suitable for a raw material powder such as alumina, silica, calcia, and magnesia. An organic solvent and a binder are added and mixed to form a slurry, which is formed into a sheet by employing a doctor blade method.

The first and second frame-shaped ceramic green sheets 1b and 1c have through holes 1 at their central portions.
d and 1e are opened, and the through holes 1d and 1e serve as recesses for accommodating a semiconductor element.

A through hole 1f is formed in the second frame-shaped ceramic green sheet 1c, and the through hole 1f serves as a passage for the metallized wiring layer.

The through holes 1d and 1e formed in the first and second frame-shaped ceramic green sheets 1b and 1c and the through holes 1f formed in the second frame-shaped ceramic green sheet are formed in a flat ceramic green sheet. A through hole 1d formed in the center of each of the first and second frame-shaped ceramic green sheets 1b is formed in the second frame-shaped ceramic green sheet 1c by employing a well-known pressing method. Through hole 1e
It has a slightly smaller diameter.

The first ceramic green sheet 1b has a wiring conductor layer 2b serving as a metallized wiring layer on its upper surface, and the second frame-shaped ceramic green sheet 1c has an upper surface and through holes. Inside 1f, a plurality of wiring conductor layers 2c also serving as metallization wiring layers are attached.

For the wiring conductor layers 2b and 2c, a metal paste obtained by adding a suitable organic solvent and a binder to a high melting point metal powder such as tungsten, molybdenum, manganese or the like and employing a conventionally known screen printing method is used. The wiring conductor layers 2b and 2c function as conductive paths when connecting the respective electrodes of the semiconductor element to an external electric circuit.

Next, the flat ceramic green sheet 1a serving as the dummy layer and the first and second frame-shaped ceramic green sheets 1b and 1c serving as the ceramic frame are laminated one above the other. A ceramic green sheet laminate is formed by laminating a ceramic green sheet 1a serving as a dummy layer and a first and a second frame-shaped ceramic green sheets 1b and 1c serving as ceramic frames by being pressed from above and below with a pressure of cm ^2. .

Next, the ceramic green sheet laminate is fired at a temperature of about 1600 ° C. in a reducing atmosphere to thereby form a ceramic frame 1 h having a metallized wiring layer 2 on a dummy layer 1 g as shown in FIG. Are sintered integrally to obtain a ceramic sintered body 1i.

At this time, in the ceramic green sheet laminate, a plate-like ceramic green sheet 1a serving as a dummy layer is laminated on the lowermost layer, and a portion serving as a flange portion of a frame-like ceramic green sheet 1b serving as a ceramic frame is provided. Since the tip of the ceramic frame does not become a free end and is hardly deformed, the deformation of the flange portion of the ceramic frame which occurs at the time of firing is effectively prevented.

Finally, the dummy layer 1g of the ceramic sintered body 1i is ground and removed by using a surface grinding method such as a lapping machine to form a through hole E having a flange D as shown in FIG. 1 (c). The obtained ceramic frame 1 is obtained.

At this time, the lower surface of the ceramic frame 1 is extremely flat because it is ground by a surface grinding method such as a lapping machine. As a result, the bonding area between the ceramic frame 1 and the heat dissipation base is increased. It is possible to join the two very firmly.

[0031]

According to the method of manufacturing a package for housing a semiconductor element of the present invention, a flat ceramic green sheet serving as a dummy layer is laminated on the lower surface of a ceramic green sheet serving as a ceramic frame. The front end of the ceramic green sheet serving as the body is not a free end, and therefore is not easily deformed. Therefore, when this is fired, the flat ceramic green sheet serving as the lowermost dummy layer effectively prevents deformation such as warpage of the flange portion of the ceramic frame due to firing shrinkage and the like, and as a result, metallized wiring on the upper surface of the flange portion A bonding wire for connecting the semiconductor element to the layer can be accurately and firmly connected, and the semiconductor element housed therein can be accurately and reliably connected to an external electric circuit.

According to the method of manufacturing a package for housing a semiconductor element of the present invention, the dummy layer of the ceramic sintered body in which the dummy layer and the ceramic frame are integrated is ground and removed by a surface grinding method such as a lapping machine. Therefore, the lower surface of the ceramic frame can be made extremely flat,
Therefore, the joining area between the ceramic frame and the heat dissipation base can be increased, and as a result, both can be brazed firmly, and a highly airtight and highly reliable package can be obtained.

[Brief description of the drawings]

FIGS. 1A to 1C are cross-sectional views for explaining steps of a method for manufacturing a semiconductor device housing package according to the present invention.

FIG. 2 is a cross-sectional view of a conventional semiconductor element storage package.

3 (a) and 3 (b) are cross-sectional views for explaining steps in a conventional manufacturing method.

[Explanation of symbols]

1 ceramic frame 1a flat ceramic green sheet serving as a dummy layer 1b, 1c ceramic green sheet serving as a ceramic frame

Claims (1)

(57) [Claims] 1. A semiconductor element housing package comprising a ceramic frame joined to an upper surface of a heat dissipation base having a semiconductor element mounting portion so as to surround the semiconductor element mounting portion. A method of manufacturing a package for housing a semiconductor element, which is manufactured by the steps (1) to (3). (1) A step of preparing a flat ceramic green sheet to be a dummy layer and a frame-shaped ceramic green sheet to be a ceramic frame (2) A step of preparing a ceramic frame on the flat ceramic green sheet to be a dummy layer A step of laminating frame-shaped ceramic green sheets and firing them to obtain a ceramic sintered body in which the dummy layer and the ceramic frame are integrated (3) The dummy layer of the ceramic sintered body is ground and removed. Of obtaining ceramic frame