JPH06163752A - Heat-conducting resin, structure and manufacture of semiconductor device using the resin - Google Patents

Abstract

PURPOSE:To realize the structure, of a semiconductor device, wherein it uses a resin whose heat conductivity is good, its cost is low and its conductivity is good by a method wherein a first filler and a second filler which are composed of metal particles and of thin insulating resins covering the whole surface of the metal particles are filled. CONSTITUTION:A semiconductor element 5 is fixed onto a substrate 10 by a die attaching agent or the like. After that, a bonding pad 8 on the surface of the semiconductor element 5 and a wiring pattern 9 on the substrate 10 are connected by a wire 7. The semiconductor element 5, the wire 7, the bonding pad 8, the wiring pattern 9 and one part of the substrate are covered with a heat-conducting resin 6. A structure wherein a highly heat-conducting property and a highly electric insulating property are obtained at the same time is formed, and a structure wherein the semiconductor element 5 is protected from humid surroundings is formed. Consequently, since the heat-conducting resin 6 is used instead of an epoxy-based resin which is used generally and whose heat conductivity is bad, heat can be made to escape from the side of the heat-conducting resin 6, and a highly heat-dissipating property can be obtained by the simple structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat conductive resin, a structure of a semiconductor device using the heat conductive resin, and a method of manufacturing a semiconductor device using the heat conductive resin.

[0002]

2. Description of the Related Art Conventionally, as a means for improving the thermal conductivity of a resin, there is known a method of improving the apparent thermal conductivity of the resin by filling the resin with powder such as crushed material of a substance having good thermal conductivity. It was being done. Specific examples of powders such as crushed materials were metals, ceramics, etc., but there are also cases where they are used by mixing with silica, and further, the flow characteristics of the resin, and the powder granulated into spherical shapes to improve the filling property. In some cases, the resin was filled.

In a semiconductor device requiring heat dissipation, the heat conductive resin thus produced is directly applied to the semiconductor element.
Alternatively, heat is radiated from the semiconductor element by indirect contact and inclusion.

[0004]

However, in the prior art, when it was attempted to improve the thermal conductivity of the resin, metal,
Powder of crushed ceramics, a large amount of granulated powder must be filled in the resin, and since the ceramics are expensive, in order to improve the thermal conductivity at low cost, simply,
In many cases, a large amount of metal powder was filled in the resin.
Since this resin is filled with a large amount of metal powder, it has improved thermal conductivity, but has a problem that it is difficult to obtain electrical insulation.

Furthermore, when this resin is used in a semiconductor device that requires heat dissipation, there is a risk of short-circuiting of conductive members such as semiconductor elements, substrate wirings, lead frames, etc. that constitute the semiconductor device. There is a problem that the total cost is increased even though the resin is inexpensive because it is necessary to electrically insulate it by another means and eventually the complicated manufacturing process is performed.

In view of the above problems, the present invention provides an inexpensive resin having good thermal conductivity, and a structure of a cheap semiconductor device having good thermal conductivity and a method of manufacturing the semiconductor device using the resin. It is intended to be provided.

[0007]

In the heat conductive resin of the present invention, in order to solve the above-mentioned problems, a means for filling a first filler composed of metal particles and a thin insulating resin covering the entire surface of the metal particles is adopted. .

Means are provided for filling the metal particles and a first filling and a second filling made of a thin insulating resin covering the entire surface of the metal particles.

The heat conductive resin is mainly composed of epoxy resin.

The heat transfer resin is mainly composed of silicone resin.

The heat transfer resin is mainly composed of polyimide resin.

Further, in the structure of the semiconductor device using the heat conductive resin of the present invention, in order to solve the above problems, a semiconductor element, a fixing member for the semiconductor element, and an electrical connecting member for the semiconductor element are provided. A means for covering with the heat transfer resin is taken.

Means are provided for covering the semiconductor element die-attached on the lead frame and the lead frame electrically connected to the semiconductor element with the heat conductive resin.

Means is provided for covering the substrate, the semiconductor element die-attached on the substrate, and the wiring pattern formed on the substrate and electrically connected to the semiconductor element with the heat conductive resin.

A substrate die-attached on the lead frame, a semiconductor element die-attached on the substrate,
A means for covering the wiring pattern formed on the substrate and electrically connected to the semiconductor element and the lead frame with the heat conductive resin is taken.

In the structure of the semiconductor device, a means for covering a plurality of semiconductor elements with the heat conductive resin is provided.

The semiconductor element is mounted on both sides of the substrate.

In the semiconductor device in which the semiconductor element, the fixing member of the semiconductor element, and the electrical connecting member of the semiconductor element are covered with the heat conductive resin, the heat conductive resin is provided with a radiator. I take the.

The radiator employs means for forming the heat-conducting resin itself into an uneven shape.

The radiator employs means for retrofitting the radiator to the heat conductive resin.

Further, in the method of manufacturing a semiconductor device using the heat conductive resin of the present invention, the semiconductor element and the fixing member of the semiconductor element are fixed, and the electrical connecting member of the semiconductor element is electrically connected. After the connection, a means having a step of covering the heat transfer resin with a dispenser or a transfer mold is taken.

[0022]

According to the present invention, since the filler made of a thin insulating resin covering the entire surface of the metal particles is filled in the resin, the metal particles can be used as a good heat conductive material.
Furthermore, in order to increase the apparent thermal conductivity of the resin, even if the filling amount of the metal particles is increased, since the surface is covered with a thin insulating resin, an electrical short between the metal particles does not occur,
It has the effect of simultaneously imparting high heat conductivity and high electrical insulation to the resin.

Generally, the coefficient of thermal expansion of the resin and the filler differ from each other by one to two digits, and the desired coefficient of thermal expansion can be obtained by mixing them, but in the present invention, the insulating resin having a thin surface is used. Since the structure is such that the metal particles covered with and other fillers are mixed in the resin, the resin and the surface of the resin are thinly insulated by utilizing the difference in the coefficient of thermal expansion between the resin and the metal and the other fillers. By optimizing the mixing ratio of the metal particles covered with the resin and the other filler, it also has the function of obtaining the optimum apparent thermal expansion coefficient of the resin.

Further, according to the present invention, since the conductive member such as the semiconductor element, the substrate wiring, the lead frame and the like constituting the semiconductor device is covered with the above-mentioned heat conductive resin, these members are directly connected to each other. Even if it is covered with the heat-conductive resin, it has the effect of simultaneously obtaining high thermal conductivity and high electrical insulation.

Next, according to the present invention, since the outer surface of the heat conductive resin covering the semiconductor element has an uneven structure, the contact area with air increases, and a radiator is attached to the outer surface of the heat conductive resin. Since it has a structure, it has an effect of reducing the thermal resistance of the semiconductor device.

Further, according to the present invention, since the semiconductor element is connected to the substrate, the lead frame, or the like, and then the semiconductor element is covered with the heat conductive resin by dispensing or transfer molding, the semiconductor element is provided on the substrate, the lead frame, or the like. Since it can be transported between the processes together with the above, it has an effect of being able to pass through a dispensing or transfer molding process.

[0027]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic enlarged view showing a heat conductive resin of the present invention, 1 is a base resin, 2 is metal particles, and 3 is 2
It is an insulating resin that covers the metal particles. The resin of No. 1 is often an epoxy resin, a silicone resin, or the like, but a polyimide resin, an acrylic resin, a vinyl resin, or the like may be selected, and any resin may be used.
The metal particles of No. 2 can be made of a material such as nickel powder, solder powder, iron powder, which is inexpensive and has high thermal conductivity and which is easily available. If the purpose of using the resin is low thermal resistance, a metal having high thermal conductivity may be used, and if the cost is low, an inexpensive metal may be used, and any metal may be used depending on the purpose. As a method for forming the metal particles, a known crushing method, granulation method, atomizing method, disk method or the like may be used. An insulating resin film is formed on the thus-prepared metal particles by a coating method, a drip method, or the like.
For example, the metal particles are irradiated with an insulating resin dissolved in a solvent by spraying or the like, and the solvent is dried to form a film of the insulating resin. The insulating resin may be any electrically insulating material, but is often a styrene-based or acrylic-based resin.

When the base resin is melted and used, the insulating resin has a melting point higher than that of the base resin so that the insulating resin film is not melted and the electrical insulating property of the heat conductive resin is not lowered. Is preferable. The base resin is filled with the metal particles covered with the insulating resin thus prepared to prepare the heat conductive resin. The higher the filling rate of the metal particles with respect to the base resin, the closer the apparent thermal conductivity of the base resin becomes to that of the metal particles, and the higher the thermal conductivity.

Next, a case will be described in which the resin is filled with a filler other than metal particles in order to control the apparent thermal expansion coefficient of the resin and to reduce the amount of the resin used. FIG. 2 is a schematic enlarged view of a heat conductive resin showing another embodiment of the present invention. In FIG. 2, reference numeral 4 denotes a filler other than metal particles such as silica, calcium carbonate, ceramics, plastics and the like. Generally, the coefficient of thermal expansion of the resin and the filler is different by one to two digits, and the desired coefficient of thermal expansion can be obtained by mixing them, but in the present embodiment, the metal whose surface is covered with a thin insulating resin is used. Since the structure is such that particles and other fillers are mixed in the resin, the resin and the surface are covered with a thin insulating resin by utilizing the difference in thermal expansion coefficient between the resin, the metal, and the other fillers. By optimizing the mixing ratio of the metal particles and the other filler, the desired thermal expansion coefficient of the resin can be obtained. Further, the amount of resin used can be reduced by the volume displaced by the filling material.

FIG. 3 is a structural diagram of a semiconductor device using the heat conductive resin of the present invention. In FIG. 3, reference numeral 5 denotes a semiconductor element, which is fixed on a substrate 10 with a die attach agent or the like, and then a bonding pad 8 formed on the surface of the semiconductor element by a wire 7 and a wiring pattern 9 formed on the substrate. Connect. The semiconductor element and wires, the bonding pad, the wiring pattern and a part of the substrate are covered with the heat conductive resin 6 described above, and the structure is such that high thermal conductivity and high electrical insulation can be obtained at the same time. The structure protects the semiconductor element from the humidity environment. Gold or aluminum is often used for the wire. As the substrate, an epoxy resin such as ceramics or FR-4, a polyimide resin, an aramid resin, or silicon is often used. A copper foil, a conductive paste, a metal thin film, or the like is often used as the wiring pattern. In recent years, the operating speed of semiconductor devices has continued to rise, and power consumption has risen in proportion to it, so this measure of heat dissipation is very important. Since the heat conductive resin is used instead of the epoxy resin having poor conductivity, heat can be released from the heat conductive resin side.
It can be seen that high heat dissipation is obtained with such a simple structure. Of course, if the substrate on the back surface side of the semiconductor element is also covered with the heat conductive resin, higher heat dissipation can be obtained. Furthermore, even if a plurality of semiconductor elements are mounted on the substrate, the semiconductor elements may be mounted on both surfaces of the substrate and the semiconductor elements may be covered with a heat conductive resin.

FIG. 4 is a structural view of a semiconductor device using a heat conductive resin showing another embodiment of the present invention. In FIG. 4, reference numeral 5 denotes a semiconductor element placed on the lead frame 11, which is formed on the surface of the semiconductor element by the wire 7 after fixing the semiconductor element on the lead frame with a die attach agent or the like. The bonding pad 8 and the lead frame 11 are connected. The semiconductor element, wires, bonding pads, and a part of the lead frame are covered with the heat conductive resin 6 described above, so that high thermal conductivity and high electrical insulation can be obtained at the same time. It has a structure that protects the semiconductor element from the environment. Since the semiconductor element is directly exposed to the heat conductive resin,
Heat is radiated from the entire surface of the semiconductor element other than the lead frame surface. Gold or aluminum is often used for the wire. 42 alloy has been often used as a lead frame, but copper has also come to be used in response to the recent increase in heat generation of semiconductor elements.

FIG. 5 is a structural view of a semiconductor device using a heat conductive resin showing another embodiment of the present invention. In FIG. 5, reference numeral 5 denotes a semiconductor element, which is fixed on the substrate 10 with a die attach agent or the like, and then the bonding pad 8 and the substrate 10 formed on the surface of the semiconductor element by the wire 7
The wiring pattern 9 formed above is connected. The substrate is placed on the lead frame 11, and the wiring pattern and the lead frame are connected by wires. The semiconductor element and wire, bonding pad, wiring pattern, substrate and part of the lead frame are covered with the heat conductive resin 6 described above, so that a structure having high thermal conductivity and high electrical insulation at the same time is obtained. In addition, the structure protects the semiconductor element from the humidity environment. Since the semiconductor element is directly exposed to the heat conductive resin, heat is radiated from the entire surface of the semiconductor element other than the substrate surface. Of course, even if a plurality of semiconductor elements are mounted on the substrate, the semiconductor elements may be mounted on both surfaces of the substrate and the semiconductor elements may be covered with the heat conductive resin. In particular, when mounting multiple semiconductor elements with a complicated heat-generating part structure or mounting semiconductor elements on both sides of the board, it is difficult to use one side of the board for heat dissipation structure as is generally done. However, with the structure of the present invention, heat can be directly radiated from the resin that covers the semiconductor element.

FIG. 6 is a structural diagram of a heat dissipation structure of a semiconductor device using the heat conductive resin according to the present invention. In FIG.
Reference numeral 5 denotes a semiconductor element placed on the lead frame 11, and the wire 7 connects the bonding pad 8 formed on the surface of the semiconductor element and the lead frame 11. The semiconductor element, wires, bonding pads, and a part of the lead frame are made of the above-mentioned heat conductive resin 6
It has a structure that can obtain high thermal conductivity and high electric insulation at the same time, and also has a structure that protects the semiconductor element from the humidity environment. The heat generated from the semiconductor element is dissipated mainly into the air from the concavo-convex portion of the heat conductive resin 12 through the heat conductive resin that is in direct contact with the semiconductor element. Compared to the case where the outer surface of the semiconductor device is flat, the outer surface of the heat-conductive resin covering the semiconductor element is uneven, so that the contact area with air increases, so the thermal resistance of the semiconductor device decreases. For the purpose of lowering the thermal resistance, the heat conducting resin may be provided with a radiator on the outer surface of the heat conducting resin without providing the concavo-convex portion to reduce the thermal resistance of the semiconductor device. Of course, the structure shown in FIG. 5 may be used to form an uneven portion on the heat conductive resin, or a radiator may be attached to the outer surface of the heat conductive resin to reduce the thermal resistance of the semiconductor device. Further, only the necessary part of the structure of the semiconductor device described so far may be covered with the heat conductive resin, and the other part than the necessary part may be covered with the known resin.

Next, a specific manufacturing method for obtaining the structure shown in FIGS. 3 to 6 will be described. The heat transfer resin can be made into a liquid form or a solid form depending on the preparation method. When the liquid form is a dispenser, when it is a solid form, it is placed at a desired place by transfer molding.
In the structure shown in FIG. 3, the heat conductive resin 6 is dispensed in a state where the bonding pad 8 formed on the surface of the semiconductor element 5 and the wiring pattern 9 formed on the substrate 10 are connected by the wire 7 to each other. Often applied by. In the structure of FIG. 4, the semiconductor element 5 mounted on the lead frame 11 and the bonding pad 8 formed on the surface of the semiconductor element by the wire 7 and the lead frame 11 are connected to each other. In the structure, the wire 7 connects the bonding pad 8 formed on the surface of the semiconductor element 5 and the wiring pattern 9 formed on the substrate 10, and the substrate is placed on the lead frame 11. Further, the wiring pattern and the lead frame are connected to each other by a wire, and the heat conductive resin 6 is often formed by transfer molding in a mold having a standard outer shape, for example, an EIAJ-compliant mold. . At that time, of course,
The unevenness as shown in (1) may be simultaneously formed on the heat conductive resin, or a radiator may be attached to the outer surface of the heat conductive resin to reduce the thermal resistance of the semiconductor device. Further, the heat-conducting resin 6 may be applied by a dispenser only to a place where heat dissipation is required, and the other parts may be formed by transfer molding using a known resin.

[0036]

According to the present invention, since the filler made of a thin insulating resin covering the entire surface of the metal particles is filled in the resin, inexpensive metal particles can be used as the good heat conducting material.
Furthermore, since the surface of the metal particles is covered with a thin insulating resin, even if the filling amount of the metal particles whose surface is covered with a thin insulating resin is increased to increase the apparent thermal conductivity of the resin, The effect of being able to impart high thermal conductivity and high electrical insulation properties to the resin at the same time at low cost without using expensive filling materials such as ceramics with low thermal resistance Have.

Further, according to the present invention, the metal particles whose surface is covered with a thin insulating resin can be mixed with other fillers. Therefore, when it is desired to change the apparent coefficient of thermal expansion of the resin, the resin and the surface can be changed. By optimizing the mixing ratio of the metal particles covered with a thin insulating resin and other fillers, the optimum thermal expansion coefficient of the resin can be obtained, and the amount of resin used can be reduced, so It also has the effect of reducing costs.

Further, according to the present invention, since the semiconductor element, the substrate wiring, the lead frame and the like which constitute the semiconductor device are covered with the above-mentioned heat conductive resin, the structure has high thermal conductivity. The above-mentioned heat-conducting resin having electrical insulation at the same time has an effect of efficiently generating heat from the semiconductor element and being insulated from the external environment without deterioration of electrical characteristics.

With the structure of the present invention, heat can be radiated directly from the heat-conducting resin covering the semiconductor element. Therefore, the semiconductor device having a plurality of semiconductor elements having a complicated structure of the heat-generating portion or the semiconductors on both sides of the substrate can be used. Even in a semiconductor device on which elements are mounted, there is an effect that a heat dissipation structure for a semiconductor device can be formed easily and inexpensively without taking a complicated heat dissipation structure.

Further, according to the present invention, the heat conducting resin covering the semiconductor element is provided with the uneven portion on the outer surface, or the heat conducting resin is not provided with the uneven portion, and the radiator is attached to the outer surface of the heat conducting resin. Since the heat dissipation structure is adopted, it is possible to easily further reduce the thermal resistance.

Further, according to the method of manufacturing a semiconductor device using the heat conductive resin of the present invention, since a dispenser or an existing transfer mold can be used, an expensive dedicated mold is not required, and the cost is low and the cost is low. It is possible to manufacture a semiconductor device having high performance and heat dissipation on a delivery date.

[Brief description of drawings]

FIG. 1 is a schematic enlarged view showing a heat conductive resin of the present invention.

FIG. 2 is a schematic enlarged view showing a heat conductive resin of the present invention.

FIG. 3 is a structural diagram of a semiconductor device using the heat conductive resin of the present invention.

FIG. 4 is a structural diagram of a semiconductor device using a heat conductive resin showing another embodiment of the present invention.

FIG. 5 is a structural diagram of a semiconductor device using a heat conductive resin showing another embodiment of the present invention.

FIG. 6 is a structural diagram of a heat dissipation structure of a semiconductor device using the heat conductive resin of the present invention.

[Explanation of symbols]

 1 Base Resin 2 Metal Particles 3 Insulating Resin 4 Filler 5 Semiconductor Element 6 Heat Transfer Resin 7 Wire 8 Bonding Pad 9 Wiring Pattern 10 Substrate 11 Lead Frame 12 Roughness of Heat Transfer Resin

Claims (15)

[Claims] 1. A heat transfer resin, characterized in that it is filled with a first filler composed of metal particles and a thin insulating resin that covers the entire surface of the metal particles. 2. A heat conductive resin, characterized by being filled with a first filling and a second filling made of metal particles and a thin insulating resin covering the entire surface of the metal particles. 3. The heat conductive resin according to claim 1, wherein the heat conductive resin is mainly made of epoxy resin. 4. The heat transfer resin according to claim 1, wherein the heat transfer resin is mainly composed of a silicone resin. 5. The heat conductive resin according to claim 1, wherein the heat conductive resin is mainly made of polyimide resin. 6. A semiconductor device using a heat conductive resin, wherein a semiconductor element, a fixing member for the semiconductor element, and an electrical connecting member for the semiconductor element are covered with the heat conductive resin. Construction. 7. The heat-conductive resin covers the semiconductor element die-attached on the lead frame and the lead frame electrically connected to the semiconductor element. A structure of a semiconductor device using the heat transfer resin described. 8. A substrate, a semiconductor element die-attached on the substrate, and a wiring pattern formed on the substrate and electrically connected to the semiconductor element are covered with the heat conductive resin. 7. A structure of a semiconductor device using the heat conductive resin according to claim 6. 9. A substrate die-attached on a lead frame, a semiconductor element die-attached on the substrate, and a wiring formed on the substrate and electrically connected to the semiconductor element and the lead frame. 7. The structure of a semiconductor device using a heat conductive resin according to claim 6, wherein the pattern is covered with the heat conductive resin. 10. The structure of a semiconductor device using a heat conductive resin according to claim 6, wherein a plurality of semiconductor elements are covered with the heat conductive resin in the structure of the semiconductor device. 11. The structure of a semiconductor device using a heat conductive resin according to claim 6, wherein the semiconductor element is mounted on both surfaces of the substrate. 12. A semiconductor device in which the semiconductor element, a fixing member of the semiconductor element, and an electrical connection member of the semiconductor element are covered with the heat conductive resin,
A structure of a semiconductor device using a heat conductive resin, characterized in that the heat conductive resin is provided with a radiator. 13. The structure of a semiconductor device using a heat-conductive resin according to claim 12, wherein the heat-radiating resin itself has an uneven shape in the radiator. 14. The structure of a semiconductor device using a heat conductive resin according to claim 12, wherein the heat radiator is formed by adding the heat radiator to the heat conductive resin. 15. A step of fixing the semiconductor element and a fixing member of the semiconductor element, electrically connecting an electrical connecting member of the semiconductor element, and then covering the heat conductive resin with a dispenser or a transfer mold. A method of manufacturing a semiconductor device using a heat-conductive resin, which comprises: