JPH0414504B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor device, and particularly to a semiconductor device having an insulating laminated substrate with excellent heat dissipation.

[Prior art]

Conventionally, semiconductor devices have an airtight structure in which a semiconductor element such as an IC or LSI is fixed in a recess of an insulating substrate, and after connecting leads, the top is sealed with a ceramic plate or metal plate. Widely used with equipment.

The insulating substrate that fixes semiconductor elements is required to have high thermal conductivity, but in addition to this, other conditions must be met, such as excellent insulation, high mechanical strength, and a coefficient of thermal expansion close to that of silicon. It is necessary. Currently, alumina substrates are mainly used as substrates that satisfy these conditions to some extent.

However, alumina substrates have a drawback in that they have particularly poor heat dissipation properties, which poses a major obstacle in increasing the scale and integration of semiconductor devices with high power consumption, such as bipolar ICs and GaAs ICs.

One method to improve the heat dissipation characteristics of semiconductor devices is to attach a heat dissipation plate around the alumina substrate, but this increases the number of parts, increases the size of the device, and increases the number of assembly steps. There are many drawbacks. Therefore, there has been a desire for an insulating substrate with improved heat dissipation characteristics.

[Problem that the invention seeks to solve]

An object of the present invention is to eliminate the above drawbacks and provide a semiconductor device having an insulating substrate with excellent heat dissipation.

[Means for solving problems]

The semiconductor device of the present invention includes an insulating laminated substrate containing aluminum nitride as a main component and a semiconductor element fixed in a recessed portion of the laminated substrate.

Metal wiring is formed inside the aluminum nitride (AlN) laminated substrate, and is connected to a semiconductor element by a wire, and this metal wiring is connected to an external lead.

This laminated board is made by adding additives to AlN powder.
It is desirable that the composition contains at least one type of acetylide compound of Ca, Sr, and Ba, and the total content thereof is 0.002 to 10% by weight.

〔Example〕

Next, embodiments of the present invention will be described using the drawings.

FIG. 1 is a sectional view of an embodiment of the present invention.

In FIG. 1, a semiconductor element 2 is fixed to a recessed portion of an insulating laminated substrate 1 mainly composed of AlN by solder or the like. The electrodes of the semiconductor element 2 are connected to metal wiring 4 formed in the laminated substrate 1 by gold wires 3, and the metal wiring 4 is further connected via a metallized layer 5 formed on the side surface of the laminated substrate 1. Connected to lead 6. A metal cap 8 made of, for example, a 42 alloy is hermetically sealed on the top of the laminated substrate 1 with a solder 7.

The laminated substrate 1 used here can be made, for example, by the following steps.

First, high purity AlN powder of 95% or more (particle size 10 μm)
(below), one of the acetylide compounds of Ca, Sr, and Ba
0.02 to 10% by weight of seeds and organic vehicle are added and mixed, and then passed through a roller to form a green sheet.

Next, this green sheet is dried at 100 to 200°C, and then metal wiring is printed and formed on a predetermined portion of the green sheet by a thick film method. Next, a predetermined number of green sheets were stacked and thermocompressed at approximately 100℃ and 200 to 300Kg/cm ² , and then heated to 1800℃ in a non-oxidizing atmosphere such as N ₂ gas.
Bake at ℃ for 2 hours.

The properties of the AlN laminated substrate 1 made in this way are a thermal conductivity of 70 to 140 W/mk and a specific resistance of 10 ¹³ Ω.
cm, mechanical strength (bending strength) 50Kg/mm ² , coefficient of thermal expansion
The temperature was 4.3×10 ^-6 /℃. Comparing these values with those of conventional alumina substrates, the thermal conductivity is 4 to 4.
The mechanical strength was 1.5 times higher, and the thermal expansion coefficient was 3/4, all of which exhibited excellent properties as an insulating substrate.

FIG. 2 shows the relationship between the amount of Ca, Sr, and Ba acetylide compounds added as additives and the thermal conductivity. As shown in Figure 2, CaC ₂
The thermal conductivity is the highest when the amount of addition is used, but the relationship curves between the amount added and the thermal conductivity are all similar, and there is a peak at the amount of addition of 2 to 3%. Although FIG. 2 shows the characteristics of each individual acetylide compound, almost the same weighted average values were obtained even when a mixture of these compounds was added.

In this way, the semiconductor device according to the present invention has good heat dissipation characteristics because the insulating substrate is made from a raw AlN sheet printed with metal wiring, and is bipolar.
This enables high integration of semiconductor devices that consume a lot of power, such as ICs and GaAs ICs. In addition, its mechanical strength is superior to that of conventional alumina substrates, and its coefficient of thermal expansion is also superior to that of conventional alumina substrates.
Since it is close to Si, there is less thermal strain on the semiconductor element due to thermal cycles, and a highly reliable semiconductor device can be obtained.

〔Effect of the invention〕

As explained in detail above, according to the present invention,
By using a laminate made of aluminum nitride as an insulating substrate, a semiconductor device with excellent heat dissipation and high reliability can be obtained, which is highly effective.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an embodiment of the present invention, and Fig. 2 is a sectional view of an embodiment of the present invention.
FIG. 3 is a diagram showing the relationship between the proportion of additives in AlN and thermal conductivity. DESCRIPTION OF SYMBOLS 1... Laminated substrate, 2... Semiconductor element, 3... Gold wire, 4... Metal wiring, 5... Metallized layer, 6...
...Lead, 7...Solder, 8...Metal cap.

Claims (1)

[Claims] 1 Aluminum nitride is the main component, including Ca, Sr, and Ba.
1. A semiconductor device comprising: an insulating laminated substrate containing 1 to 4% by weight of one or more acetylide compounds; and a semiconductor element fixed to a recess of the laminated substrate.