Packaging method used for high-power integrated circuit

Technical Field

This invention is a kind of the output high power integrated circuit using the advanced packaging technology, which belongs to the technical field of manufacturing a semiconductor package.

Background Art

As is well known, the current International semiconductor integrated circuit in the development of two directions: as a CMOS, BiCMOS, such as low voltage and low power consumption of the representative of the integrated circuit; the second is to DMOS, the representative Bipolar of the high-voltage high-power integrated circuit. For 1st circuit, because the output power is relatively small, almost without the requirement for heat radiation of the package; and for the latter circuit, because of its large output power, will produce more heat, the heat radiation of the package therefore have high requirements. If poor heat radiation of the package, will be the temperature of the chip rapidly rise, the normal rated output power does not reach the time, the circuit enters the over-temperature protection state, thus affecting the normal use of the circuit. From this it can be seen, constraining bottleneck in the development of high power integrated circuit often on the package. Currently, the market for large-power output circuit is generally provided with a package of two forms: a. As shown in Figure 1, the chip is directly mounted on the metal base; the earth, an external radiating fin metal base. Base metal is generally copper. Such packaging heat radiating effect is good, but because the copper price is high, the cost is high; b. As shown in Figure 2, the chip is housed in a small metal base, and then bonding the metal base on the large metal substrate, metal substrate an external radiating fin. Base metal is generally copper, the metal substrate is generally relatively cheap other metal, such as aluminum and the like. This kind of package because the copper base is relatively small, the cost is low, but the heat dissipation effect is poor, because of the copper bottom seat are not in direct contact with the radiating fin, and only through the metal base plate is in contact with the heat sink, a larger heat resistance therefore, influence to the heat radiation. Therefore, to make the high-power output of the output circuit power not affected by package, measures must be taken to, the cost of the package on the premise of as small as possible to reduce thermal resistance, improve the heat radiation performance.

Content of the invention

Technical problem: the purpose of this invention is to provide a method for high-power integrated circuit packaging method, the thermal resistance of the package is reduced, improving the heat radiation of the package. The punching of the metal base plate, the metal base is embedded into the metal the method of the base plate, the heat radiation of the package is greatly improved.

Technical proposal: the invention for large-power integrated circuit packaging method of embedding metal base of the metal base plate of the packaging technology, as follows:

1.) in the metal base plate of a size slightly smaller than the hole of the metal base,

2.) embedded into the metal base plate of the metal base,

3.) in the base metal and solder paste is printed on the metal base plate,

4.) the chip and the lead wire pins are respectively attached to the metal base and the metal substrate,

5.) the chip, lead foot, together with the metal base and the metal substrate is sintered in the sintering furnace, the temperature of the 210-230 the [...][...] ,

6.) between the chip and the lead wire through the wire bonding,

7.) under a microscope, the check for any shred shedding or drain bonding,

8.) coating the surface of the chip,

9.) capsule, with the shell cover the metal base plate,

10.) the lead foot gluten cutting and bending,

11.) test open-short circuit situation,

12.) filling and sealing and drying, the temperature of the 100-110 the [...][...] , time 1 hour, to complete.

Beneficial effect: by comparing Figure 3 and Figure 4 series, we can find that: in a conventional packaging process, the metal base through the metal base plate is in contact with the outer fin, the thermal resistance is relatively large, the heat dissipation is relatively slow; and the embedding of the metal base plate of the metal base after the packaging process, the metal base contact directly with the heat sink, the thermal resistance is relatively small, so that heat can be more quickly.

From the above we can draw conclusions, metal base after the embedding process, can be very good in the improvement of the constraints of conventional technology for high-power integrated circuit heat dissipation factor.

Through the experiment, compared with the conventional process of the encapsulated high-power integrated circuit embedded with the metal base of the same circuit packaging process, two kinds of circuit is used for the metal base of copper, which is used for the metal base plate is aluminum, found that in the condition of the same environmental condition, the process for embedding the metal base than the conventional process of the encapsulated circuit encapsulated circuit thermal resistance reduced by about 45%, data are as follows: the conventional process encapsulated circuit thermal resistance as the 3.8 [...] /W, is embedded into the metal base for the encapsulated circuit thermal resistance as the 2.1 [...] /W. That is to say, the metal base after the embedding process, the heat radiation of the circuit than was originally is improved by about 50%, in the high-power semiconductor integrated circuit with the increasing development of the today, will undoubtedly produce great competitiveness, thus is conducive to promoting the International power integrated circuit constantly to the development of more high requirements.