JP2742624B2 - Alumina sintered body having metallized metal layer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention has a metallized metal layer in which a metallized metal layer is bonded to an alumina-based sintered body having an alumina (Al ₂ O ₃ ) content of 92.0% by weight or more. The present invention relates to improvement of an alumina-based sintered body.

(Prior Art) Conventionally, alumina-based sintered bodies have excellent properties such as electrical insulation and chemical stability. Therefore, electronic devices such as a semiconductor element housing package for housing a semiconductor element and a circuit board having circuit wiring are used. A metallized metal layer used as a circuit wiring conductor is adhered and bonded to the surface of an alumina sintered body, which is widely used for components.

The metallized metal layer on the surface of such an alumina sintered body is usually formed by adding an organic solvent and a solvent to a high melting point metal powder such as tungsten (W) or molybdenum (Mo) into a paste to form a non-sintered alumina. It is applied to the body surface by screen printing or the like, and thereafter, the unfired alumina-based molded body is fired at a temperature of about 1500 ° C. in a reducing atmosphere, and a glass component interposed between alumina crystals of the alumina-based sintered body is formed. A part is transferred between the metal particles of the high melting point metal, and the alumina crystal and the high melting point metal are bonded to each other via a glass component to be adhered and bonded to the surface of the alumina-based sintered body.

In order to firmly braze the external lead terminals to the outer surface of the metallized metal layer, or to effectively prevent oxidative corrosion of the metallized metal layer, a metal such as nickel (Ni) or gold (Au) is usually used. A metal that is conductive and has excellent corrosion resistance is deposited by plating.

(Problems to be Solved by the Invention) However, this conventional metallized metal layer using a high melting point metal such as tungsten (W) or molybdenum (Mo) is made of alumina (Al ₂ O ₃ ) which is an alumina sintered body. Content 90.0
If the amount is less than 10% by weight, the amount of the glass component interposed between the alumina crystals of the alumina-based sintered body is large, and the transition of the glass component between the high-melting metal particles is made smooth so that the metallized metal layer is formed on the alumina-based sintered body. Although it can be strongly bonded, when the alumina (Al ₂ O ₃ ) content of the alumina-based sintered body exceeds 92.0% by weight, the amount of glass components interposed between alumina crystals decreases, and the glass components Transfer between the high melting point metal particles is also deteriorated, and the metallized metal layer cannot be firmly adhered and bonded to the alumina sintered body.

In addition, in order to eliminate the above-mentioned drawbacks, unfired alumina molded body coated with a paste made of a high melting point metal powder is about 1600.
It is conceivable to bake at a high temperature of ℃ to promote the transfer of the glass component interposed between the alumina crystals of the alumina sintered body between the high melting point metal particles.

However, when the paste composed of the high melting point metal powder is fired at a high temperature, the reaction between the particles of the high melting point metal powder proceeds greatly, and the grain growth proceeds too much, resulting in a so-called oversintering state. As a result, the gap between the high-melting metal particles becomes wide, and the transition of the glass component interposed between the alumina crystals of the alumina-based sintered body into the gap due to the capillary phenomenon becomes insufficient, so that the metallized metal layer is still formed of alumina. It has a disadvantage that it cannot be firmly adhered and bonded to a sintered body.

Therefore, in order to solve the above-mentioned drawbacks, the applicant of the present application firstly added 0.5 to 3 of rhenium (Re) to at least one of tungsten (W) and molybdenum (Mo) as a metallized metal layer.
Those containing 0.0% by weight were proposed.

According to such a metallized metal layer, rhenium (Re) suppresses the reaction between tungsten (W) and molybdenum (Mo) particles, leaving many fine voids between tungsten (W) and molybdenum (Mo) particles. The transfer of the glass component into the voids by the capillary phenomenon is facilitated, whereby the metallized metal layer can be firmly bonded to the surface of the alumina sintered body.

However, in the case of an alumina sintered body having an alumina (Al ₂ O ₃ ) content of 92.0% by weight or more, the glass component is tungsten (W) because the absolute amount of the glass component interposed between the alumina particles is small. The gap between molybdenum (Mo) particles cannot be completely filled, and the metallized metal layer has a large amount of voids on its surface. Therefore, when nickel (Ni), gold (Au), or the like is applied to the surface of the metallized metal layer by plating, the plating solution enters and remains in the voids of the metallized metal layer, causing the metallized metal layer to corrode and discolor. Also, there is a problem to be solved such that the metallized metal layer is eluted on the alumina sintered body to short-circuit the adjacent metallized metal layers.

(Object of the Invention) The present invention was devised in view of the above-mentioned drawbacks, and its object is to provide an alumina-based sintered body having an alumina (Al ₂ O ₃ ) content of 92.0% by weight or more, such as discoloration on the surface. It is an object of the present invention to provide an alumina-based sintered body having a metallized metal layer formed by firmly attaching and joining a metallized metal layer having almost no formation of voids that cause the metallized metal layer.

(Means for Solving the Problems) The alumina-based sintered body having a metallized metal layer according to the present invention is characterized in that at least one of tungsten and molybdenum contains 0.5 to 30.0% by weight of rhenium and at least one of alumina and zirconia has a content of 1.0 to 1.0. A metallized metal layer containing 30.0% by weight is bonded to an alumina sintered body having an alumina content of 92.0% by weight or more.

Rhenium (Re) contained in the metallized metal layer of the present invention is tungsten (W) or molybdenum (M).
o) is a component for suppressing the interparticle reaction. If the content is less than 0.5% by weight, the above-mentioned desired properties are not imparted. If the content exceeds 30.0% by weight, rhenium (Re) becomes tungsten (W). ), An intermetallic compound is generated with molybdenum (Mo), and the electrical resistance of the metallized metal layer becomes large. Therefore, the content of rhenium (Re) is 0.
It is specified in the range of 5 to 30.0% by weight.

Alumina (Al ₂ O ₃ ) and zirconia (ZrO ₂ ) compensate for the shortage of the absolute amount of the glass component transferred between the particles of tungsten (W) and molybdenum (Mo), and the glass component is tungsten (W) and molybdenum (Mo). (Mo) is a component that promotes the migration of the glass component so as to fill in all the particles. If the content is less than 1.0% by weight, the above properties are not provided. If the content exceeds 30.0% by weight, the metallized metal layer Greatly increases the electrical resistance of the material, making it unsuitable for circuit wiring conductors such as semiconductor element storage packages and wiring boards, so that the content of alumina (Al ₂ O ₃ ) and zirconia (ZrO ₂ ) is 1.0
To 30.0% by weight.

When the particle size of alumina (Al ₂ O ₃ ) and zirconia (ZrO ₂ ) exceeds 1.0 μm, alumina (Al ₂ O ₃ ) and zirconia (ZrO ₂ ) are exposed on the surface of the metallized metal layer, and Nickel (Ni), gold (Au) on metal layer surface
When plating metal or the like, the adherence of the plated metal layer becomes sparse, and it becomes impossible to firmly braze the external lead terminals and the like to the metallized metal layer, or appearance defects occur, so that alumina (Al ₂ O ₃ ), And zirconia (ZrO ₂ ) preferably have a particle size of 1.0 μm or less.

(Examples) Next, the present invention will be described based on examples.

Example 1 First, tungsten (W), molybdenum (Mo), rhenium (Re) having a particle size of 1 to 5 μm as a starting material and a particle size of 0.6 were used.
μm alumina (Al ₂ O ₃ ) and zirconia (ZrO ₂ )
An organic solvent and a solvent are added thereto, and the mixture is kneaded with a kneader for 10 hours to obtain a metallized metal layer paste sample.

Sample Nos. 1, 14, and 27 are comparative samples for comparison with the product of the present invention, and are metallized metal layer pastes generally used conventionally.

Using the metallized metal layer paste sample thus obtained, the content of alumina (Al ₂ O ₃ ) was 90.0% by weight and 92.0% by weight.
20 patterns of 10.0mm long, 0.5mm wide and 20μm thick are printed on the outer surface of each of the unfired alumina moldings of 0wt% and 95.0wt% by screen printing at intervals of 0.3mm. Then, this is fired at a temperature of 1550 ° C. or 1600 ° C. in a reducing atmosphere (nitrogen-hydrogen atmosphere), and a metallized metal layer is adhered and bonded to the surface of the alumina sintered body.
Then, the electric resistance of the metallized metal layer was measured by a resistance measuring instrument, and the average value was determined as the electric resistance value of each metallized metal layer.

Also, a 1.5 mm square metallized metal layer was formed on the surface of each of the alumina sintered bodies, and a 1.0 mm square, 40.
One end of a 0mm 42Alloy (Fe-Ni alloy) metal pillar is brazed through silver brazing (Ag: 72%, Cu: 28%), and then the end opposite to the brazed part of the metal pillar Was pulled in the vertical direction, the tensile strength when the metallized metal layer was peeled off from the alumina sintered body was examined, and the average value was calculated as the bonding strength of the metallized metal layer.

When a metal column was brazed to the metallized metal layer, a Ni plating layer having a thickness of 1.5 μm was applied to the outer surface of the metallized metal layer.

Further, 20 metallized metal layers having a length of 30.0 mm, a width of 3.0 mm and a thickness of 20 μm were adhered to and bonded to the surface of the alumina-based sintered body in the same manner as described above, and a thickness of 1.5 mm was applied to the surface of each metallized metal layer. A nickel (Ni) plating layer with a thickness of μm was deposited and subjected to a temperature and humidity cycle test specified in MIL-STD-883-1004 for 240 hours (10 cycles), and the outer surface of each metallized metal layer was observed with a microscope. The number of discolored things was counted.

 The results are shown in Table 1.

Example 2 Next, the particle diameter of tungsten (W), molybdenum (Mo), and rhenium (Re) was set to 1 μm, and alumina (Al ₂ O ₃ )
The particle diameter of zirconia (ZrO ₂ ) was set to the value shown in Table 2 to be applied to the surface of the alumina-based sintered body in the same manner as in Example 1.
A 5 mm square metallized metal layer is adhered and bonded, and then a 1.0 mm square, 40.0 mm long 42Alloy (Fe
-Ni alloy) has one end face of a silver pillar (Ag: 72%,
(Cu: 28%) and then braided, and then pull the end opposite to the brazed part of the metal column vertically to check the tensile strength when the metal column was peeled off from the metallized metal layer,
The average value was calculated as the bonding strength between the metallized metal layer and the metal column.

When a metal column was brazed to the metallized metal layer, a Ni plating layer having a thickness of 1.5 μm was applied to the outer surface of the metallized metal layer.

 The results are shown in Table 2.

(Effect of the Invention) As can be seen from the above experimental results, the conventional metallized metal layer has an alumina (Al ₂ O ₃ ) content of 9
When the firing temperature is 1550 ° C, the bonding strength shows a large value of 5.8 kg / mm ^{2. Although} the metallized metal layer is firmly adhered to and bonded to the alumina sintered body, When the alumina (Al ₂ O ₃ ) content exceeds 92.0% by weight and the firing temperature is 1600 ° C., the bonding strength is 2.6 kg / mm ² or less, and the bonding strength of the metallized metal layer is greatly reduced. On the other hand, the metallized metal layer of the present invention has an alumina (Al ₂ O ₃ ) content of 92.0
Even if the baking temperature is as high as 1600 ° C or more, the bonding strength of the metallized metal layer shows a value of 4.3 kg / mm ² or more, and the metallized metal layer is extremely firmly bonded to the alumina sintered body. You can see that it is.

When the particle size of alumina (Al ₂ O ₃ ) and zirconia (ZrO ₂ ) is set to 1 μm or less, alumina (Al ₂ O ₃ ) and zirconia (ZrO ₂ ) are not exposed on the surface of the metallized metal layer, and are not metallized. It can be seen that it is also possible to firmly attach external lead terminals and the like to the metal layer.

Further, the metallized metal layer of the present invention has an electric resistance of 30.
It is as small as mΩ / SQ or less, and can be sufficiently used as a circuit wiring conductor for a package for housing semiconductor elements, a wiring board, and the like.

Further, the metallized metal layer of the present invention hardly discolors even in a temperature / humidity cycle test, and the intergranular gap of tungsten (W) and molybdenum (Mo) constituting the metallized metal layer is determined by the glass component of the alumina-based sintered body. You can see that it is completely buried.

Therefore, the alumina-based sintered body having the metallized metal layer of the present invention is firmly bonded to the alumina-based sintered body without forming a void on the surface of the metallized metal layer, and a semiconductor element housing package for housing a semiconductor element or the like. It is suitably used for electronic components such as circuit boards having circuit wiring conductors.

Claims (1)

(57) [Claims] At least one of tungsten and molybdenum
A metallized metal layer containing 0.5 to 30.0% by weight of rhenium and 1.0 to 30.0% by weight of at least one of alumina and zirconia is bonded to an alumina-based sintered body having an alumina content of 92.0% by weight or more. An alumina-based sintered body having a metallized metal layer.