JP2604621B2 - Manufacturing method of semiconductor device storage package - Google Patents

Description

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

[Conventional technology]

2. Description of the Related Art In recent years, as information processing apparatuses have become higher in performance and higher in speed, semiconductor elements constituting the information processing apparatuses have been rapidly increasing in density and integration. Therefore, the amount of heat generated per unit area and unit volume of the semiconductor element increases, and how to efficiently remove the heat has been a problem in order to operate the semiconductor element normally and stably.

Conventionally, as a method of removing a semiconductor element, as shown in FIG.
Prepare a semiconductor element storage package having a structure in which the insulating frame 13 is brazed and attached so as to surround the convex portion 12,
This is performed by placing the semiconductor element 14 on the upper surface of the convex portion 12 of the metal base 11, absorbing the heat generated from the semiconductor element 14 to the metal base 11, and releasing the absorbed heat to the atmosphere.

In the semiconductor element housing package, the metal base 11 is made of copper-tungsten whose thermal expansion coefficient is close to that of the insulating frame 13 so that thermal stress does not occur between the metal base 11 and the insulating frame 13 attached to the upper surface. It is made of an alloy, and has good wettability with the brazing material so that the brazing material when the insulating frame 13 is brazed and attached to the outer surface is firmly joined to the outer surface, for example, nickel (Ni)
An even metal layer 15 is deposited by plating.

The insulating frame 13 has molybdenum (Mo) on its lower surface,
A metallized metal layer 16 made of a refractory metal such as manganese (Mn), tungsten (W) or the like is formed on the metal substrate 11, and the metallized metal layer 16 is formed on a metal substrate 11 by silver brazing (silver-copper alloy).
Insulation frame by brazing through brazing material 17 such as
13 is attached on the metal base 11.

[Problems to be solved by the invention]

However, in this conventional package for housing a semiconductor element, the entire surface of the outer surface of the metal base 11, that is, the entire outer surface including the upper surface of the convex portion on which the semiconductor element 14 is mounted, has wettability (bonding property). A) a metal layer 15 having good adhesion, and a stress generated due to a slight difference in the thermal expansion coefficient between the convex side surface of the metal base 11 and the inner peripheral surface of the insulating frame 13. Usually, a gap of about 0.5 mm is formed in order to effectively absorb
At the time of brazing through 17, a part of the molten brazing material 17 creeps up in the gap by capillary action, flows out and adheres to the upper surface of the convex portion of the metal base 11, and the surface becomes rough, and as a result, the metal The semiconductor element cannot be firmly attached to the upper surface of the convex portion of the base, or the semiconductor device is attached with an inclination to the upper surface of the convex portion of the metal substrate, and wire bonding for connecting each electrode of the semiconductor element to an external lead pin is used. There was a disadvantage that work could not be performed.

[Object of the invention]

The present invention has been devised in view of the above drawbacks, and has as its object to enable an insulating frame to be firmly brazed to the upper surface of a metal substrate, and to braze the insulating frame to the upper surface of the convex portion of the metal substrate. The semiconductor device can be firmly attached to the upper surface of the convex portion of the metal base, and each electrode of the semiconductor device can be securely connected to each of the external lead pins. It is an object of the present invention to provide a method for manufacturing a semiconductor device storage package that can be manufactured.

[Means for solving the problem]

The method for manufacturing a semiconductor element storage package according to the present invention includes:
A metal substrate having a convex portion on which the semiconductor element is mounted at the center, and a metal layer having good bonding properties with the brazing material on the outer surface, and a frame made of an electrically insulating material, A covering layer having excellent heat resistance and non-brazing material bonding properties is deposited on the side or upper side of the convex portion of the metal substrate, and then the insulating frame is formed on the metal substrate so as to surround the convex portion provided on the substrate. The method is characterized in that the body is brazed, and thereafter, the coating layer is peeled off from the projections of the metal base and removed.

〔Example〕

Next, the present invention will be described in detail based on the embodiment shown in FIG.

FIG. 1 shows an embodiment of a semiconductor device housing package manufactured by the manufacturing method of the present invention, wherein 1 is a metal base, and 2 is an insulating frame.

The metal base 1 is provided with a convex portion 1a at the center of the upper surface, and a semiconductor element is mounted on the convex portion 1a via an adhesive.

The metal base 1 functions to directly conduct and absorb the heat generated by the semiconductor element and to release the absorbed heat to the atmosphere, so that thermal expansion does not occur between the metal base 1 and the insulating frame 2 described later. A material having a coefficient close to that of the insulating frame 2 and having good thermal conductivity, that is, a copper-tungsten alloy (Cu-W
Alloy).

The metal substrate 1 is formed, for example, by pressing tungsten powder (about 10 μm) at a pressure of 1000 kg / cm ² and firing it at a temperature of about 2300 ° C. in a reducing atmosphere to form a porous tungsten sintered body. A body is obtained, and then formed by impregnating the porous portion of the tungsten sintered body with copper heated and melted at a temperature of 1100 ° C. using a capillary phenomenon.

The metal substrate 1 has a metal layer 1b made of nickel (Ni) or the like having excellent wettability (bonding property) and excellent corrosion resistance on the entire outer surface of the metal substrate 1 by a conventionally known electroless plating method or electrolytic plating method. Is layered. The metal layer 1b increases the bonding strength between the brazing material and the metal base 1 when brazing an insulating frame 2 to be described later to the metal base 1, and prevents the metal base 1 from being oxidized and corroded. Works.

When the metal layer 1b is deposited by, for example, an electroless plating method, first, the metal substrate 1 is coated with 2 g of ammine palladium chloride.
/, Ethylenediaminetetraacetic acid (E
DTA) 10 g /, sodium hydroxide 100 g / liquid temperature 70
Activated by immersing in an active solution at 5 ° C. for 5 to 10 minutes and nickel sulfate 30 g / sodium citrate 10 g /
, Sodium succinate 20g /, sodium acetate 20g /
Then, the substrate is immersed in a nickel plating solution of 3 g / dimethylamine borane at a temperature of 65 ° C. for about 10 minutes to deposit and deposit nickel, thereby forming a layer on the entire outer surface of the metal substrate 1.

An insulating frame 2 is attached to the outer peripheral edge of the upper surface of the metal substrate 1 so as to surround the convex portion 1a provided on the upper surface of the metal substrate 1. The metal substrate 1 and the insulating frame 2 A space for accommodating 3 is formed therein.

The insulating frame 2 is made of, for example, alumina ceramics. A green sheet (raw sheet) is formed by adding a suitable organic solvent and a solvent to alumina ceramic powder to form a slurry and employing a doctor blade method. Thereafter, the green sheet is manufactured by subjecting the green sheet to an appropriate punching process, laminating a plurality of sheets, and firing at a high temperature.

A metallized metal layer 8 made of a metal such as tungsten or molybdenum is adhered on the lower surface of the insulating frame 2, and the metallized metal layer 8 and the metal substrate 1 are formed by silver brazing (silver-copper alloy) or the like. Is attached onto the metal substrate 1 by brazing through the brazing material 9.

In this case, since the metal layer 1b having good wettability (bonding property) with the brazing material is layered on the outer surface of the metal base 1, the joining of the brazing material 9 with the metal layer 1b and the metallized metal layer 8 is performed. The strength can be increased, so that the insulating frame 2 can be firmly attached on the metal base 1.

The insulating frame 2 also has molybdenum (Mo) therein.
A conductive layer 4 made of a metal such as tungsten (W) is provided. The conductive layer 4 connects an electrode of the semiconductor element 3 to a lead pin 5.
To the external lead pin 5 at one end.
However, a wire 6 connected to the electrode of the semiconductor element 3 is attached to the other end.

The external lead pins 5 attached to the conductive layer 4 provided on the insulating frame 2 serve to connect each electrode of the semiconductor element 3 housed therein to an external circuit, and are made of Kovar (Fe-Ni-Co alloy). A pin made of a metal such as or 42Alloy is used.

In order to improve the electrical connection between the external lead pins 5 and an external circuit,
In order to prevent the external lead pins 5 from being oxidized and corroded, a metal having good conductivity and excellent corrosion resistance made of nickel (Ni), gold (Au) or the like is deposited by a conventionally known plating method. It is desirable.

Further, a lid 7 is attached to the upper surface of the insulating frame 2 via an adhesive such as glass or resin, whereby the inside of the semiconductor element housing package is completely hermetically sealed.

Thus, the protrusion 1a of the metal base 1 to which the insulating frame 2 is attached.
The semiconductor element 3 is mounted thereon, and the electrodes of the semiconductor element 3 are connected to the conductive layer 4 via wires 6 and the lid 7 is attached to the upper surface of the insulating frame 2 to thereby obtain a semiconductor as a final product. Device.

Next, a method for manufacturing the semiconductor device housing package of the present invention will be described.

First, as shown in FIG. 2 (a), a metal layer 1b having a good wettability (bonding property) with a brazing material is deposited on the outer surface of the semiconductor device having a convex portion 1a on which a semiconductor element is mounted at the center. Metal substrate 1 formed
Prepare

Next, as shown in FIG. 2 (b), a coating layer 10 having excellent heat resistance and non-brazing material bonding property (poor wettability with brazing material) is applied to the side surface of the convex portion 1a of the metal substrate 1. Let it. This coating layer
When brazing an insulating frame 2 to be described later on the metal base 1, the brazing material creeps up the side surface of the convex portion 1 a of the metal base 1,
It functions to prevent the outflow and adhesion to the upper surface of the convex portion.

The coating layer 10 is preferably made of an inorganic material such as alumina ceramics.For example, an organic solvent suitable for alumina ceramic powder, a solvent is added and mixed to form a paste,
The paste is printed on the side surface of the convex portion 1a of the metal substrate 1 and dried and fired at a temperature of about 100 ° C. to be deposited on the side surface of the convex portion 1a of the metal substrate 1.

The coating layer 10 made of alumina ceramics has a low bonding strength with the side surface of the convex portion 1a of the metal base 1, and can be easily separated from the side surface of the convex portion 1a by applying an external force.

Further, the coating layer 10 may be applied not only to the side surface of the convex portion 1a of the metal base but also to both the upper surface and the side surface.

Then, as shown in FIG. 2 (C), the insulating frame 2 is placed on the metal base 1 so as to surround the protruding portion 1a provided on the base 1, and the insulating frame 2 is connected to the metal base 1 via the brazing material 9. Braze.

At the time of this brazing, the molten brazing material 9 tends to crawl on the side surface of the convex portion 1a of the metal base 1, but the side surface of the convex portion 1a has excellent heat resistance and non-brazing material bonding property (brazing material). Is clogged up because the coating layer 10 having poor wettability is effectively prevented, and as a result, the molten brazing material flows out and adheres to the upper surface of the convex portion 1a, and the convex portion 1a There is no need to make the upper surface of the semiconductor device rough, thereby lowering the attachment strength of the semiconductor element, or to attach the semiconductor device with an inclination.

As the brazing material 9 for brazing the insulating frame 2 onto the metal base 1, for example, silver brazing (silver-copper alloy) is preferably used, and the frame of the brazing material 9 is insulated from the metal base 1. Frame 2
The metal base 1 and the insulating frame 2 are brazed by being sandwiched between them and heated and melted at a temperature of about 900 ° C.

Finally, as shown in FIG. 2 (d), the coating layer 10 deposited on the side surface of the convex portion 1a of the metal base 1 is peeled off, thereby completing a semiconductor element housing package as a product.

The coating layer 10 is peeled and removed by placing a metal base 1 having an insulating frame 2 brazed on the upper surface thereof in a water tank filled with water.
And ultrasonic waves of 26 to 28 KHz are applied to the water in the water tank to apply an external stress to the coating layer 10.

〔The invention's effect〕

As described above, according to the manufacturing method of the present invention, the coating having excellent heat resistance and non-brazing material bonding property (poor wettability with brazing material) is provided on the side surface of the convex portion of the metal substrate on which the semiconductor element is mounted. When the insulating frame is brazed on the metal base because the layer is applied, the molten brazing material is effectively prevented from creeping up the side surface of the convex portion, and the brazing material flows out and adheres to the upper surface of the convex portion. The surface is never rough.

Therefore, the upper surface of the convex portion of the metal substrate 1 is always flat, and the semiconductor element can be horizontally and firmly attached.

In addition, since the mounting of the semiconductor element can be made horizontal, each electrode of the semiconductor element can be connected to the external lead pin using an automatic wire bonder, and the connection between them can be made accurately and securely. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a semiconductor device housing package manufactured by the manufacturing method of the present invention. FIG. 2 is a cross-sectional view showing each step for explaining the manufacturing method of the present invention. FIG. 1 is a sectional view of a conventional package for housing a semiconductor element. 1: Metal substrate, 1a: Convex part 1b: Metal layer, 2: Insulating frame 9: Brazing material, 10: Coating layer

Claims (2)

(57) [Claims] 1. A frame comprising an electrically insulating material and a metal base having a convex portion on which a semiconductor element is mounted at a center portion, and a metal layer having good bonding properties with a brazing material layered on an outer surface. Is prepared, and a coating layer having excellent heat resistance and non-brazing material bonding property is applied to the side surface or the upper side surface of the convex portion of the metal substrate. Then, the convex portion provided on the metal substrate is surrounded on the metal substrate. A method for manufacturing a package for housing a semiconductor element, comprising: brazing an insulating frame body in the above manner; and thereafter, peeling and removing the coating layer from a convex portion of the metal base. 2. The method according to claim 1, wherein the coating layer applied to the projections of the metal base is made of an inorganic material.