JP2503775B2 - Substrate for semiconductor device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a semiconductor device substrate which can sufficiently cope with higher integration and higher power consumption of a semiconductor device.

[Conventional technology]

2. Description of the Related Art Conventionally, as a substrate for a semiconductor device, for example, as shown in a schematic explanatory view in FIG. _2, an insulating plate material C ′ made of an aluminum oxide (Al ₂ O ₃ ) sintered body has C and C
u The thin plate material B'is liquid-phase bonded. For this liquid phase bonding, for example, copper oxide (Cu ₂ O) is formed on the bonding surface of the Cu thin plate material,
In the state of being laminated with the Al ₂ O ₃ insulating plate material, 1965 to 108
This is a method of heating at 5 ° C. to generate a liquid phase between the Cu ₂ O and Cu on the joint surface and bonding, and the upper surface of the Al ₂ O ₃ insulating plate material C ′ of the Cu thin plate materials. The side is the conductor for circuit formation, and the bottom side is for soldering. In this state, the solder material usually made of Pb-Sn alloy (melting point: 450 ° C
It is known to have a structure in which a heat sink plate material A'made of Cu is bonded using D '(hereinafter referred to as solder).

[Problems to be Solved by the Invention]

However, the amount of heat generated in a semiconductor device has increased due to the recent higher integration and higher power consumption of the semiconductor device, and along with this, the amplitude of the temperature cycle of repeated heat generation and cooling received by the semiconductor device is also large. However, in the conventional semiconductor device substrate having the above structure, when exposed to such a severe temperature cycle, for example, the thermal expansion coefficient of an Al ₂ O ₃ sintered body having a purity of 96% is 96%. 6x
10 ^-6 / ℃, Cu so that it is 17.2 × 10 ^-6 / ℃, Al
_Due to the large thermal expansion difference existing between the ₂ O ₃ insulating plate material C ′ and the Cu thin plate material B ′, not only the ductility of the Al ₂ O ₃ insulating plate material, which is not ductile, easily occurs, but also the solder material D'has a melting point as low as 450 ° C. or lower, which easily causes thermal fatigue, and causes a peeling phenomenon in this solder material layer. In this state, heat generated in the semiconductor device The problem that heat radiation from the heat sink plate material A'cannot be performed satisfactorily occurs, and at this point, it is not possible to sufficiently cope with high integration and high power consumption of the semiconductor device.

[Means for solving the problem]

Therefore, the inventors of the present invention have conducted research to develop a semiconductor device substrate capable of accommodating high integration and high power consumption of the semiconductor device from the above viewpoints.
As shown in the schematic explanatory view of FIG. 1, a structure in which an insulating plate material C is made of an aluminum nitride (AlN) sintered body, and a circuit-forming conductor thin plate material B and a heat sink plate material A are bonded to both surfaces of the insulating plate material C, In addition, the conductor thin plate material B and the heat sink plate material A are each formed of any one of W, Mo, W alloy, and Mo alloy, and the bonding to the insulating plate material C by weight% ( The same shall apply hereinafter), eg Ag-29% Cu-4% T
When using a high melting point brazing filler metal (in the present invention, a brazing filler metal having a melting point of 750 ° C. or higher) D made of an i alloy, Cu-3% Ti alloy, Cu-3% Zr alloy, or the like, The insulating plate material, the conductor thin plate material B, and the heat sink plate material A are firmly joined by the high melting point brazing material D that does not cause thermal fatigue even under severe temperature cycles, and the AlN insulating plate material C is made of Al ₂ O. ₃ The thermal conductivity of the sintered body is 17 W / K ・ m, while that of the AlN sintered body is 160 W / K ・ m, which is a good conductor of heat. Mo that constitutes the conductor thin plate material B and the heat sink plate material A
Thermal conductivity of 142 W / K ・ m, thermal conductivity of W: 167 W / K ・ m, which are extremely close to each other, and regarding the coefficient of thermal expansion, AlN sintered body: 3.6 × 10 ^-6 / ℃, Mo: 5.3 × 10 ^-6 / ℃, W:
It is very close to 4.7 × 10 ^-6 / ° C., for example, W-10% Cu alloy: 5.5 × 10 ^-6 / ° C. Therefore, in the semiconductor device substrate having the above structure, the insulating plate material C made of AlN is used. Between the conductor thin plate material B and the heat sink plate material A,
It has been found that the exfoliation of the brazing material caused by thermal fatigue and the cracking of the insulating plate material C caused by a large difference in thermal expansion do not occur, and excellent heat diffusivity and heat dissipation can be exhibited. .

This invention was made on the basis of the above findings, in which W, Mo, W is formed on one surface of an insulating plate material made of an AlN sintered body.
Alloy, and a conductor forming thin plate material for circuit formation made of any one of the Mo alloy, the same W, M on the other surface of the insulating plate material.
The semiconductor device substrate is characterized in that a heat sink plate material made of any one of o, W alloy, and Mo alloy is joined by using a high melting point brazing material.

〔Example〕

Next, the semiconductor device substrate of the present invention will be specifically described with reference to examples.

As shown in FIG. 1, the insulating plate material C has a width of 50 m.
m × thickness: 0.63mm × length: 75mm dimensions Purity: 99% Al
N sintered body is prepared, and it is made of the material shown in Table 1 and has a width of 45 mm x thickness: 0.3 mm x length: 70 mm, and a conductor forming thin plate material B for circuit formation, and a width: 50mm x thickness: 3mm
× Length: Prepare heat sink plate materials A each having a dimension of 75 mm, and in a state where they are superposed with the high melting point brazing filler metals D shown in Table 1, respectively, in a vacuum,
The substrates 1 to 8 of the present invention were brazed at a temperature of 880 ° C. for 10 minutes. Each was manufactured.

Also, for the purpose of comparison, as shown in FIG. 2, as insulating plate material C ′, width: 50 mm × thickness: 0.63 mm × length: 75 mm, purity: 96% Al ₂ O ₃ sintering For body and also for circuit formation and soldering, width: 45 mm × thickness: 0.3 mm × length:
Oxygen-free copper thin plate materials B '(2 sheets) having a dimension of 70 mm are prepared respectively, and in a state where these both are superposed, oxygen: 1
Cu ₂ O formed in the oxidizing atmosphere by heating in an Ar atmosphere containing 10% by volume at a temperature of 1075 ° C. for 50 minutes.
And Cu by generating a liquid phase by the eutectic of Cu and Cu on the joint surface,
Then, this joined body was used with a solder material D ′ made of Pb-60% Sn alloy having a thickness of 300 μm, and width: 50 mm × thickness: 3 mm × length:
A conventional substrate was manufactured by soldering to one surface of a heat sink plate material A'made of oxygen-free copper having a dimension of 75 mm.

Next, the resulting substrates 1 to 8 of the present invention and the conventional substrate were subjected to a repeated heating and cooling test in which one cycle of heating to a temperature of 150 ° C. and then cooling to −55 ° C. was performed. Is observed every 20 cycles until the insulating plate material C is separated from the conductor thin plate material B and the heat sink plate material A, and the insulating plate material C is cracked. The number of cycles until peeling between B ′ and the heat sink plate material A ′ and cracking of the insulating plate material C ′ were also observed and measured every 20 cycles. The results are shown in Table 1.

〔The invention's effect〕

From the results shown in Table 1, the substrates 1 to 8 of the present invention show excellent thermal conductivity and heat dissipation because they do not cause peeling or cracking even after repeated heating and cooling under severe conditions. On the other hand, it is clear that in the conventional substrate, peeling or cracking occurs relatively early.

As described above, the semiconductor device substrate of the present invention does not cause peeling or cracking even under severe temperature cycles, and exhibits excellent thermal conductivity and heat dissipation properties. Therefore, high integration and high power consumption of the semiconductor device can be achieved. It is a very reliable one that can fully cope with.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of a semiconductor device substrate of the present invention, and FIG. 2 is a schematic explanatory diagram of a conventional semiconductor device substrate. A, A '... Heat sink plate material, B, B' ... Thin plate material, C '...
... Insulating plate material, D ... High melting point brazing material, D '... Solder material.

Continuation of the front page (56) Reference JP 63-289950 (JP, A) JP 63-65653 (JP, A) JP 62-226645 (JP, A) JP 61-30042 (JP , A)

Claims (1)

(57) [Claims] 1. A circuit forming conductor thin plate material made of any one of W, Mo, W alloys and Mo alloys is formed on one surface of an insulating plate material made of an aluminum nitride sintered body, and the other surface of the insulating plate material is made of And a heat sink plate material made of any one of W, Mo, W alloys, and Mo alloys, respectively, which is joined using a high melting point brazing material.