JPH05144965A - Package for containing electronic component - Google Patents

Abstract

PURPOSE:To provide a package for containing an electronic component in which a cover is rigidly connected to an insulating base to normally and stably operate the component for a long period. CONSTITUTION:The package for containing an electronic component has an insulating base l and a cover 2, and connects the cover 2 to a metallized metal layer 8 covering the base 1 through a sealer 9 made of solder to contain the component therein. The surface of the layer 8 covering the base 1 is covered with a metal layer 10 made of nickel containing cobalt in such a manner that the concentration of cobalt in the layer 10 is gradually increased toward the surface to be connected with the solder from the surface of the layer 8. The layer 8 of the base 1 is solder-bonded to the cover 2 over a wide area to completely airtightly seal a vessel 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component storage package for storing electronic components such as semiconductor elements, crystal oscillators, piezoelectric oscillators and the like.

[0002]

2. Description of the Related Art Conventionally, an electronic component housing package for housing electronic components, for example, a package for semiconductor elements, is made of an electrically insulating material such as aluminum oxide sintered body, and the semiconductor element is provided at the substantially central portion of its upper surface. A semiconductor element is provided with an insulating base having a mounting portion for accommodating and having a metallized wiring layer made of a high melting point metal powder such as tungsten, molybdenum, or manganese led out from the periphery of the mounting portion to the outside. An external lead terminal attached to the metallized wiring layer via a brazing material such as silver brazing for electrically connecting to a circuit and a metallic lid, and a semiconductor element mounting portion of an insulating substrate. A semiconductor element is mounted and fixed on the substrate with an adhesive, and each electrode of the semiconductor element and the metallized wiring layer are electrically connected via a bonding wire and an insulating substrate is formed. Are joined by a sealing material comprising a lid of solder on the upper surface, a semiconductor device as a product by encapsulating a semiconductor element hermetically in the interior of the container consisting of an insulating substrate and the lid.

In the conventional package for housing a semiconductor element, the lid is joined to the insulating substrate by metallizing a high melting point metal powder such as tungsten, molybdenum or manganese on the main surface of the insulating substrate facing the lid. This is done by depositing a metal layer and a metal layer made of nickel, and joining the lid to the metallized metal layer of the insulating substrate via solder.

The metal layer made of nickel, which is deposited on the metallized metal layer of the insulating substrate, serves to improve the wettability of the metallized metal layer with respect to solder, and the metallized metal layer is coated on the metallized metal layer by a well-known plating method. Be applied by.

[0005]

However, in this conventional package for storing electronic parts, nickel deposited on the metallized metal layer of the insulating substrate has good wettability with respect to solder but poor spreadability of solder. When the lid is joined onto the metallized metal layer of the insulating substrate via the solder, the solder does not spread sufficiently on the surface of the metallized metal layer of the insulating substrate, and as a result, the solder between the metallized metal layer of the insulating substrate and the lid is soldered. There was a drawback that the reliability of the airtight sealing of the container was greatly reduced due to the partial bonding, and the electronic parts housed inside could not be operated normally and stably for a long period of time. .. Therefore, in order to solve the above-mentioned drawbacks, it is considered that cobalt is contained in the metal layer made of nickel deposited on the surface of the metallized metal layer of the insulating substrate to improve the spreadability of the solder.

However, although the spreadability of the solder is improved by containing cobalt in nickel, it is easily absorbed by the solder, and when the lid is bonded onto the metallized metal layer of the insulating substrate via the solder, the surface of the metallized metal layer is joined. The nickel containing cobalt of is absorbed by the solder, and the metallized metal layer having poor wettability and spreadability with the solder is exposed at the joint, and as a result, the lid can be firmly bonded to the metallized metal layer of the insulating substrate. Induces the drawback of not being able to.

[0007]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and an object of the present invention is to firmly join a lid to an insulating base and to operate electronic parts housed therein normally and stably for a long period of time. An object of the present invention is to provide a package for storing electronic components.

[0008]

SUMMARY OF THE INVENTION The present invention comprises an insulating substrate and a lid, and the lid is joined to a metallized metal layer deposited on the insulating substrate through an encapsulant made of solder, so that the inside of the electronic component is electronically sealed. What is claimed is: 1. A package for accommodating electronic parts, comprising: depositing a metal layer made of nickel containing cobalt on a surface of a metallized metal layer deposited on the insulating base; and cobalt of the metal layer. It is characterized in that the content concentration is gradually increased from the surface of the metallized metal layer toward the surface to which the solder is joined.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view for explaining a semiconductor element housing package for housing a semiconductor element of the electronic component housing package of the present invention, in which 1 is an insulating base made of an electrically insulating material, and 2 is a lid. .. The insulating base 1 and the lid 2 form a container 3 for housing the semiconductor element 4.

The insulating base 1 is provided with a recess 1a which forms a space for accommodating the semiconductor element 4 in the center of the upper surface thereof, and the semiconductor element 4 is provided on the bottom surface of the recess 1a with glass, resin,
It is attached via an adhesive material such as a brazing material.

The insulating substrate 1 is made of an electrically insulating material such as an aluminum oxide sintered body, a mullite sintered body, an aluminum nitride sintered body, and a silicon carbide sintered body. Alumina (Al ₂
O ₃ ), silica (SiO ₂ ), magnesia (MgO), calcia
(CaO) raw material powder such as a suitable organic solvent, the solvent is added and mixed to form a slurry and a doctor blade method is used to form a ceramic green sheet (ceramic green sheet). It is manufactured by performing appropriate punching processing on ceramic green sheets and stacking multiple sheets and firing at high temperature (about 1600 ° C).

A metallized wiring layer 5 extending from the periphery of the recess 1a to the outside of the container 3 is formed on the insulating base 1, and the electrodes of the semiconductor element 4 are bonded to the periphery of the recess 1a of the metallized wiring layer 5 by bonding. External lead terminals 7 that are electrically connected through wires 6 and that are connected to an external electric circuit are attached to a portion led out of the container 3 through a brazing material such as silver brazing.

The metallized wiring layer 5 is made of tungsten.
(W), molybdenum (Mo), manganese (Mn) and other high-melting point metal powder, a suitable organic solvent to the high-melting point metal powder, a metal paste obtained by adding and mixing a solvent is a conventionally known screen printing method. A thick film method such as the above is adopted, and the ceramic green sheet to be the insulating substrate 1 is attached in advance so that it is attached and formed so as to be led out from the periphery of the recess 1a of the insulating substrate 1 to the outside of the container 3.

The metallized wiring layer 5 is formed by depositing a metal having good conductivity such as nickel and gold and excellent corrosion resistance to a thickness of 1.0 to 20.0 μm on the exposed outer surface by plating. It is possible to effectively prevent oxidative corrosion of the metallized wiring layer 5 and the connection between the metallized wiring layer 5 and the bonding wire 6, and the metallized wiring layer 5.
The brazing attachment between the external lead terminal 7 and the external lead terminal 7 becomes extremely strong. Therefore, in order to prevent oxidative corrosion of the metallized wiring layer 5, and to firmly connect the metallized wiring layer 5 and the bonding wire 6 and braze the metallized wiring layer 5 and the external lead terminal 7, the metallized wiring layer 5 It is preferable that nickel, gold or the like is layered on the exposed outer surface to a thickness of 1.0 to 20.0 μm.

The external lead terminals 7 brazed to the metallized wiring layer 5 have a function of connecting the semiconductor element 4 housed therein to an external electric circuit.
When the semiconductor element 4 is connected to an external electric circuit, the semiconductor element 4 housed inside is electrically connected to the external electric circuit via the metallized wiring layer 5 and the external lead terminal 7.

The external lead terminal 7 is made of Kovar metal (Fe-
Ni-Co alloy), 42 alloy (Fe-Ni alloy), etc., and the ingot (lump) of Kovar metal etc. is specified by adopting the well-known metal processing methods such as rolling and punching. Is formed into a plate shape.

The outer lead terminal 7 is coated with nickel and gold on the outer surface by plating so as to have a thickness of 1.0 to 20.0 μm, so that the outer lead terminal 7 can be effectively prevented from being oxidized and corroded. Good electrical connection between the terminal 7 and the external electric circuit can be achieved. Therefore, it is preferable that the outer lead terminal 7 is layered on its outer surface with nickel and gold to a thickness of 1.0 to 20.0 μm by a plating method.

The insulating substrate 1 also has a metallized metal layer 8 deposited on the upper surface thereof, the tungsten metal layer 8
A metallic lid 2 is bonded to the via via a sealing material 9 made of solder, whereby the semiconductor element 4 is hermetically sealed inside the container 3.

The metallized metal layer 8 deposited on the upper surface of the insulating substrate 1 is made of a refractory metal powder such as tungsten, molybdenum, or manganese, and the refractory metal powder is mixed with an organic solvent or a solvent. The obtained metal paste is applied by printing onto a ceramic green sheet to be the insulating substrate 1 by adopting a conventionally known screen printing method or the like, and at the same time when the ceramic green sheet is fired at a high temperature to form the insulating substrate 1, the insulating substrate is formed. It is attached to the upper surface of 1.

The metallized metal layer 8 has an outer surface coated with a metal layer 10 made of a metal containing nickel and cobalt. The metal layer 10 is a metallized metal layer.
It works to firmly attach the lid 2 to the 8.

Further, the metal layer 10 deposited on the metallized metal layer 8 has a cobalt content concentration which gradually increases from the surface of the metallized metal layer 8 toward the surface to which the solder of the sealing material 9 is joined. As a result, when the metal lid 2 is joined to the metallized metal layer 8 of the insulating substrate 1 via the sealing material 9 made of solder, the outer surface of the metal layer 10 contains a large amount of cobalt. Has good wettability and spreadability with the solder, and the solder can be spread over the entire bonding surface of the metallized metal layer 8 at the initial stage of bonding, and when the bonding progresses, the outer surface of the metal layer 10 is absorbed by the solder. However, the absorption is stopped in the middle because the cobalt content of the metal layer 10 is gradually reduced and it is difficult to be absorbed by the solder, and it is possible to effectively prevent the metallized metal layer 8 from being directly exposed on the joint surface. Done, resulting in lid 2 It is possible to solder-bond to the metallized metal layer 8 of the insulating base 1 over a wide area, and to firmly bond the lid 2 to the insulating base 1.

The metal layer 10 in which the cobalt content concentration is gradually increased from the surface of the metallized metal layer 8 toward the surface of the encapsulant to which the solder is bonded is the metallized metal layer 8 of the insulating substrate 1. First, nickel and nickel-cobalt are sequentially deposited on the surface by a plating method, and then heat-treated to diffuse cobalt of nickel-cobalt into the underlying nickel or the metallized metal layer 8 of the insulating substrate 1. When nickel-cobalt is deposited on the surface by electrolytic plating, it is formed by gradually increasing the current density for electrolytic plating and gradually increasing the amount of cobalt deposited.

The metal content of the metal layer 10 is gradually increased from the surface of the metallized metal layer 8 toward the surface of the encapsulating material to which the solder is bonded, and the cobalt content concentration of the outer surface portion is 0.05. ~ 3.0% by weight lid
2 and the metallized metal layer 8 provided on the insulating base 1 can be solder-bonded over a wide area, and the lid 2 can be bonded to the metallized metal layer 8 of the insulating base 1 extremely firmly. Therefore, the metal layer 10 has a cobalt content concentration on its outer surface portion.
It is preferably set to 0.05 to 3.0% by weight.

The lid 2 bonded to the upper surface of the insulating base 1 is made of a metal material such as Kovar metal or 42 alloy.
By bonding the metallized metal layer 8 adhered to the insulating substrate 1 through the sealing material 10 made of solder, the semiconductor element 4 is hermetically sealed inside.

Thus, according to the package for accommodating semiconductor elements of the present invention, the semiconductor element 4 is mounted and fixed on the bottom surface of the recessed portion 1a of the insulating substrate 1 with an adhesive, and each electrode of the semiconductor element is bonded with a bonding wire 6. Metallized wiring layer
Then, the lid 2 is joined to the upper surface of the insulating base 1 through the sealing material 10 made of solder, and the semiconductor is placed inside the container 3 made up of the insulating base 1 and the lid 2. Element 4
Is hermetically sealed to form a semiconductor device as a final product.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in the above-mentioned embodiments, semiconductor elements are accommodated. Although the semiconductor element housing package has been described as an example, it can be applied to a package housing other electronic components such as a crystal oscillator or a piezoelectric oscillator, and in the above-described embodiment, the lid 2 is made of metal such as Kovar metal. Although the material is used, an electrically insulating material such as an aluminum oxide sintered body may be used. In this case, since the aluminum oxide sintered body is not joined to the solder when the lid body is joined to the insulating substrate 1 via the sealing material made of solder, the metallized metal layer made of tungsten or the like is previously formed on the lower surface of the lid body 2. Is adhered, and this is soldered to the metallized metal layer 8 provided on the insulating substrate 1.

[0027]

According to the package for housing electronic parts of the present invention, a metal layer made of nickel containing cobalt is deposited on the surface of the metallized metal layer deposited on the insulating substrate, and the cobalt content concentration of the metal layer is deposited. When the lid is joined to the metallized metal layer of the insulating substrate through the sealing material made of solder, the lid is made thicker from the surface of the metallized metal layer toward the surface to which the solder is joined. The metallized metal layer can be soldered over a wide area, and as a result, the lid is firmly bonded to the metallized metal layer of the insulating substrate to completely hermetically seal the inside of the container, and the electronic components to be housed inside can be formed. It becomes possible to operate normally and stably for a long period of time.

[Brief description of drawings]

FIG. 1 is a cross-sectional view for explaining an electronic component storage package of the present invention by taking a semiconductor element storage package for storing a semiconductor element as an example.

[Explanation of symbols]

 1 ... Insulating substrate 2 ... Lid 3 ... Container 5 ... Metallized wiring layer 7 ... External lead terminal 8 ... Metallized metal layer 9 ... Sealing material 10 ... Metal layer

Claims (1)

[Claims] 1. An electronic component is housed inside by comprising an insulating substrate and a lid, and joining the lid to a metallized metal layer adhered to the insulating substrate via a sealing material made of solder. In the package for housing electronic parts, a metal layer made of nickel containing cobalt is deposited on the surface of the metallized metal layer deposited on the insulating substrate, and the cobalt content concentration of the metal layer is adjusted to the metallized metal layer surface. A package for storing electronic components, characterized in that the solder is gradually darkened toward the surface to which the solder is bonded.