JPH0831991A - Semiconductor element storing package - Google Patents

Abstract

PURPOSE:To provide a semiconductor element storing package wherein identification marks can be formed accurately and surely on the principal surface of a heat radiating body, and a heat radiating fin can be mounted adhesively thereon, and as a result, the heat generated by the semiconductor element can be dissipated efficiently to the atomosphere. CONSTITUTION:In a semiconductor element storing package, a flat-plate-form heat radiating body 9 made of copper is brazed to the surface of an insulating container 4 for storing a semiconductor element 3. The center-line mean roughness Ra of the exposed principal surface of the heat radiating body 9 satisfies the relation of Ra<=0.15mum, and the maximum height Rmax of the heat radiating body 9 satisfies the relation of Rmax<=2.5mum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor element housing package for housing a semiconductor element such as an LSI (Large Scale Integrated Circuit Element).

[0002]

2. Description of the Related Art Conventionally, a semiconductor element housing package for housing a semiconductor element is made of an electrically insulating material such as an aluminum oxide sintered body, and is provided on a top surface with a recess for housing the semiconductor element and a periphery thereof. An insulating substrate having a plurality of metallized wiring layers made of refractory metal powder such as tungsten, molybdenum, manganese, etc. led out along the periphery, and a silver solder or the like for the metallized wiring layers for connecting the semiconductor element to an external electric circuit. The semiconductor device is composed of an external lead terminal attached via a brazing material and a lid. The semiconductor element is adhered and fixed to the bottom surface of the recess of the insulating substrate via an adhesive such as a brazing material, glass or resin. Each electrode of the element is electrically connected to the metallized wiring layer via a bonding wire, and then the semiconductor is placed inside the container consisting of the insulating base and the lid. A semiconductor device as a product by sealing the child airtight.

In the above-mentioned package for housing a semiconductor element, a metallized metal layer made of a high melting point metal powder such as tungsten or molybdenum is adhered to the lower surface of an insulating substrate, and the metallized metal layer is made of a flat plate made of copper. The heat dissipator is attached by a brazing material such as silver braze, the heat generated when the semiconductor element is operated is absorbed by the heat dissipator through the insulating base, and the absorbed heat is dissipated into the atmosphere. We try not to cause thermal destruction and thermal change in the characteristics.

The radiator is manufactured into a predetermined flat plate shape by adopting a conventionally known metal working method such as rolling and punching to an ingot made of copper.
On the exposed main surface, an identification mark indicating the product number, manufacturer, manufacturing date, etc. of the semiconductor device is formed by a printing method, a laser marking method, or the like, or the heat generated by the semiconductor element is more efficiently exposed to the atmosphere. Aluminum radiating fins for dissipating may be attached via a resin adhesive or the like.

[0005]

However, in this conventional package for accommodating semiconductor elements, when a flat heat radiator is manufactured by rolling a copper ingot, heat radiation is applied to the surface of the rolling jig. In general, a large number of grooves with a depth of about 3 to 5 μm are provided to improve the mold release from the body, so that the heat radiator processed into a flat plate also has a large number of scratches due to the grooves on its main surface. Has become. Therefore, if this heat radiator is attached to the metallized metal layer provided on the insulating substrate via a brazing material such as silver braze, a part of the brazing material will widely flow to the main surface through the scratch formed on the heat radiator. As a result, even if an identification mark is formed on the main surface of the heat radiator by a printing method or a laser marking method, the mark cannot be formed accurately and reliably.

At the same time, since a part of the brazing filler metal widely flows out to the main surface of the radiator, when a radiator fin made of aluminum is further attached to the radiator, a large gap is left between the radiator and the radiator fin. As a result, the heat transfer from the heat radiator to the heat radiation fin is greatly hindered, and the heat generated by the semiconductor element cannot be efficiently dissipated into the atmosphere.

[0007]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and an object thereof is to accurately and surely form an identification mark on the main surface of a flat plate-shaped heat radiator and to bring the heat radiation fin into close contact. Another object of the present invention is to provide a package for accommodating a semiconductor element, which can be efficiently attached to the semiconductor element to dissipate the heat generated by the semiconductor element to the atmosphere.

[0008]

The present invention is a package for accommodating a semiconductor element, which is formed by brazing a flat radiator made of copper on the surface of an insulating container for accommodating a semiconductor element, the package comprising the copper. The exposed main surface of the radiator has a centerline average roughness Ra of Ra ≦ 0.15 μm and a maximum height Rm.
It is characterized in that ax is Rmax ≦ 2.5 μm.

[0009]

According to the semiconductor element accommodating package of the present invention, the exposed main surface of the heat radiator made of copper has a center line average roughness.
Ra is Ra ≦ 0.15 μm and maximum height Rmax is Rmax ≦ 2.5
Since the thickness is μm, the capillary force on the brazing material on the main surface is small, and as a result, the flow of the brazing material to the main surface is effectively prevented.

[0010]

The present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of a package for housing a semiconductor device of the present invention, in which 1 is an insulating base and 2 is a lid. The insulating base 1 and the lid 2 constitute an insulating container 4 for housing the semiconductor element 3.

The insulating substrate 1 has a semiconductor element on its upper surface.
It is a substantially rectangular plate-like body having a recess 1a for accommodating the semiconductor 3, and the semiconductor element 3 is made of glass on the bottom surface of the recess 1a.
It is adhesively fixed via an adhesive such as resin or brazing material.

The insulating substrate 1 is made of an electrically insulating material such as an aluminum oxide sintered body. For example, aluminum oxide powder as a main raw material and silicon oxide powder, calcium oxide powder, magnesium oxide powder as a sintering aid. Aluminum oxide sinter raw material powder containing, etc. is mixed with an appropriate organic binder, solvent, plasticizer, etc. to form a slurry, and sheet forming technology such as the conventionally known doctor blade method or calender roll method is applied. A plurality of ceramic green sheets (unfired ceramic sheets) are obtained by adopting them, and then each of the above-mentioned ceramic green sheets is subjected to appropriate punching processing and these are vertically laminated in a predetermined order to form a ceramic green sheet laminate. None,
Finally, the ceramic green sheet laminate is heated to a high temperature (about
It is manufactured by firing at 1600 ℃.

Further, a plurality of metallized wiring layers 5 extending from the periphery of the recess 1a to the outer peripheral edge thereof are formed on the insulating base 1, and the metallized wiring layer 5 is provided with a plurality of metallized wiring layers 5 near the recesses 1a. Electrodes are electrically connected via bonding wires 6, and external lead terminals 7 connected to an external electric circuit are attached to the outer peripheral portion of the insulating substrate 1 of the metallized wiring layer 5 via a brazing material such as silver solder. Has been done.

The metallized wiring layer 5 is made of a refractory metal powder such as tungsten, molybdenum, or manganese, and a metal paste obtained by adding and mixing an appropriate organic binder, a solvent or the like to the refractory metal powder is used as the insulating substrate 1. By previously printing and applying a predetermined pattern to a ceramic green sheet to be formed by a conventionally known screen printing method, the insulating base 1 is adhered and formed from the periphery of the recess 1a to the outer peripheral edge.

The metallized wiring layer 5 is formed by depositing a metal such as nickel or gold, which has excellent corrosion resistance and wettability with a brazing material, on the exposed surface by a plating method to a thickness of 1.0 to 20.0 μm. This makes it possible to effectively prevent oxidative corrosion of the metallized wiring layer 5 and to firmly braze the external lead terminals 7 to the metallized wiring layer 5. Therefore, the metallized wiring layer 5
Is usually 1.0 to 2 metal with excellent corrosion resistance such as nickel and gold on the exposed surface and excellent wettability with the brazing material.
Layered to a thickness of 0.0 μm.

Further, an external lead terminal 7 is attached to the metallized wiring layer 5 through a brazing material such as silver brazing, and the external lead terminal 7 is provided in each of the semiconductor elements 3 housed inside the container 4. The semiconductor element 3 housed inside the container 4 serves to electrically connect the electrodes to an external electric circuit and connects the external lead terminal 7 to the external electric circuit so that the metallized wiring layer 5 and the external lead terminal 7 are connected. It will be connected to an external electric circuit via.

The external lead terminal 7 is made of iron-nickel-
The ingot made of a metal material such as a cobalt alloy or an iron-nickel alloy, for example, an iron-nickel-cobalt alloy or the like is formed into a predetermined plate shape by adopting a conventionally known metal working method such as rolling or punching. Is formed.

The insulating substrate 1 to which the external lead terminals 7 are attached also has a substantially square metallized metal layer 8 on its lower surface.
The metallized metal layer 8 is brazed to the metallized metal layer 8 with a substantially rectangular flat plate-shaped radiator 9 with a brazing material 10 interposed therebetween.

The metallized metal layer 8 acts as a base metal layer for attaching the heat radiator 9 made of copper to the insulating substrate 1, and is made of a refractory metal powder such as tungsten, molybdenum or manganese. It is attached to the lower surface of the insulating base 1 by the same method as the wiring layer 5.

When the metallized metal layer 8 is brazed to the metallized metal layer 8 with the heat radiator 9 via the brazing material 10, the formation of the meniscus of the brazing material 10 (the accumulation portion of the brazing material 10) is taken into consideration. From the outer periphery of the radiator 9 to 0.1 to 10 mm,
Widely formed so as to protrude outside.

Further, the metallization metal layer 8 having the substantially rectangular shape
If a radius with a radius of 0.1 to 10 mm is provided at the corners of the metallized metal layer 8, when the heat radiator 9 is brazed to the metallized metal layer 8, stress concentrates at each corner of the metallized metal layer 8 and the metallized metal layer 8 Can be effectively prevented from peeling off from the insulating substrate 1. Therefore, it is preferable that the substantially square metallized metal layer 8 has rounded corners with a radius of about 0.1 to 10 mm.

Further, the metallized metal layer 8 is formed by depositing a metal such as nickel or gold, which has excellent corrosion resistance and wettability with a brazing material, on the exposed surface by a plating method to a thickness of 1.0 to 20.0 μm. This makes it possible to effectively prevent oxidative corrosion of the metallized metal layer 8 and to firmly braze the radiator 9 made of copper to the metallized metal layer 8. Therefore, the metallized metal layer 8 is usually 1.0 to 20.0 μm of a metal having excellent corrosion resistance such as nickel and gold on its exposed surface and excellent wettability with the brazing material.
Layered to a thickness of m.

A heat radiator 9 is attached to the surface of the metallized metal layer 8 via a brazing material 10. The heat radiator 9 is, for example, a substantially rectangular flat plate made of copper such as oxygen-free copper. In this case, the heat generated by the semiconductor element 3 is satisfactorily absorbed and is also dissipated into the atmosphere to effectively prevent the semiconductor element 3 from being thermally destroyed or having its characteristics changed and malfunctioning.

The heat radiator 9 made of copper is formed into an ingot of oxygen-free copper or the like into a predetermined substantially rectangular flat plate shape by a conventionally known rolling process and punching process, and is subjected to an etching process and a polishing process. The main surface has a center line average roughness Ra of Ra ≦ 0.15 μm and a maximum height Rmax of Rmax ≦ 2.5 μm.

The main surface of the radiator 9 made of copper has a centerline average roughness Ra of Ra ≦ 0.15 μm and a maximum height Rmax of Rmax ≦ 2.
When the heat dissipating body 9 is brazed to the metallized metal layer 8 due to the smoothness of 5 μm, the capillary force of the brazing material on the main surface is small, and as a result, the brazing material on the main surface of the heat dissipating body 9. Part of 8 is rarely leaked. Therefore, the radiator
Since the unnecessary brazing material 8 does not exist on the main surface of 9, the identification mark can be formed extremely accurately and surely by the printing method or the laser marking method. At the time of attachment, the heat dissipating body 9 and the heat dissipating fins come into close contact with each other, and the heat transfer from the heat dissipating body 9 to the heat dissipating fins is improved, so that the heat generated by the semiconductor element 3 can be efficiently dissipated to the atmosphere.

The center line average roughness Ra of the main surface of the radiator 9 made of copper is Ra> 0.15 μm, or the maximum height Rmax.
If Rmax> 2.5 μm, it becomes impossible to effectively prevent the brazing material from flowing out to the main surface of the radiator 9. Therefore, the center line average roughness Ra of the main surface of the radiator 9 made of copper is limited to Ra ≦ 0.15 μm, and the maximum height Rmax is limited to Rmax ≦ 2.5 μm.

The heat dissipating body 9 is attached to the metallized metal layer 8 by facing the metallized metal layer 8 adhered to the lower surface of the insulating substrate 1 and one main surface of the heat dissipating body 9 between them. This is done by placing a brazing filler metal 10 such as silver brazing filler metal and then heating the brazing filler metal 10 to a temperature of about 850 ° C. to melt the brazing filler metal 10. In this case, the exposed main surface of the radiator 9 has a center line average roughness Ra of Ra ≦ 0.15 μm and a maximum height Rmax of Rm.
Since the ax ≤ 2.5 μm, the molten brazing material 10 is a radiator
It does not spread widely to the 9 major surfaces.

Further, the heat dissipating body 9 is coated with a metal such as nickel or gold having excellent corrosion resistance on the exposed surface by a plating method.
If the heat-dissipating body 9 is layered to a thickness of 1.0 to 20.0 μm, oxidative corrosion of the radiator 9 can be effectively prevented. Therefore, it is preferable that the exposed outer surface of the heat dissipating member 9 is layered with a metal having excellent corrosion resistance such as nickel or gold to a thickness of 1.0 to 20.0 μm by a plating method.

Furthermore, the radiator 9 has a radius at its corner.
When a radius of about 0.1 to 10 mm is formed, stress is concentrated on each corner of the heat sink 9 when the heat sink 9 is brazed to the metallized metal layer 8, and this acts on the metallized metal layer 8 to act on the metallized metal layer 8. It is possible to effectively prevent the peeling of the layer 8. Therefore, it is preferable that the radiator 9 has rounded corners with a radius of about 0.1 to 10 mm.

Thus, according to the semiconductor element housing package of the present invention, the semiconductor element 3 is formed on the bottom surface of the recess 1a of the insulating base 1.
Are bonded and fixed through an adhesive such as glass, resin, or brazing material, and each electrode of the semiconductor element 3 is connected to the metallized wiring layer 5
To the upper surface of the insulating base body 1 via a sealing material such as glass, resin, or brazing material to form the insulating base body 1 and the cover body 2. A semiconductor device as a product is obtained by hermetically housing the semiconductor element 3 inside the container 4.

[0031]

According to the package for housing a semiconductor element of the present invention, the main surface of the radiator made of copper has a center line average roughness Ra.
Ra ≦ 0.15 μm and maximum height Rmax is Rmax ≦ 2.5 μm
Therefore, the capillary force of the brazing material on the main surface becomes small, and as a result, when the heat dissipating body is brazed to the metallized metal layer provided on the insulating base, a part of the brazing material is on the main surface of the heat dissipating body. It is possible to form the identification mark on the main surface of the heat radiator very accurately and surely by the printing method or the laser marking method and to attach the heat radiation fin to the main surface of the heat radiator. In doing so, the heat radiator and the heat radiation fins are in close contact with each other, and the heat transfer from the heat radiator to the heat radiation fins is good, so that the heat generated by the semiconductor element can be efficiently dissipated to the atmosphere.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a semiconductor element housing package of the present invention.

[Explanation of symbols]

 1 ... Insulating substrate 3 ... Semiconductor element 4 ... Insulating container 5 ... Metallized wiring layer 7 ... External lead terminal 8 ... Metallized metal Layer 9 ... Radiator 10 ... Brazing material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaki Tachibana 1-1, Yamashita-cho, Kokubun-shi, Kagoshima Prefecture Kyocera Stock Company Kagoshima-Kokubun Plant

Claims (1)

[Claims] 1. A package for storing a semiconductor element, comprising a flat radiator made of copper brazed to the surface of an insulating container containing a semiconductor element, wherein the exposed main surface of the radiator made of copper is A package for housing a semiconductor element, characterized in that its centerline average roughness Ra is Ra ≦ 0.15 μm and its maximum height Rmax is Rmax ≦ 2.5 μm.