JPH1074858A - Wiring board and manufacturing method thereof - Google Patents

Abstract

(57) Abstract: A semiconductor element mounted on an insulating base cannot satisfactorily dissipate heat generated during operation to the outside, causing thermal destruction or malfunction of the semiconductor element. SOLUTION: The inorganic insulating powder of 60 to 95% by weight and 5
A wiring conductor 2 in which metal powder is bonded by a thermosetting resin is applied to an insulating substrate 1 made of a thermosetting resin of about 40% by weight and comprising the inorganic insulating powder bonded by the thermosetting resin. A wiring board comprising:
Has a surface having a thermal conductivity of at least 100 W / m · K and a high thermal conductive material powder of 60 to 95% by weight and a thermosetting resin 5 to 4
0% by weight, and a heat radiating member 5 formed by bonding the high thermal conductive material powder with the thermosetting resin is attached.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring board used for a package for housing a semiconductor element for housing a semiconductor element or a hybrid integrated circuit board.

[0002]

2. Description of the Related Art Conventionally, a wiring board, for example, a wiring board used for a semiconductor element housing package for housing a semiconductor element is made of ceramics such as an aluminum oxide sintered body, and a semiconductor element is mounted on a central portion of an upper surface thereof. And a wiring conductor made of a refractory metal powder such as tungsten or molybdenum led out from the periphery of the recess to the lower surface of the insulating base, and a semiconductor element is formed on the bottom of the recess of the insulating base. The electrodes of the semiconductor element are mounted and fixed via an adhesive such as glass, resin, brazing material or the like, and each electrode of the semiconductor element is electrically connected to a wiring conductor via an electrical connection means such as a bonding wire. A cover made of metal, ceramics, or the like is placed on the upper surface of the base with a sealing material such as glass, resin, brazing material, etc. A semiconductor device as a product by hermetically housing the semiconductor element in the recess of the insulating base, and connecting a part of the wiring conductor led out to the lower surface of the insulating base to the wiring conductor of the external electric circuit board. Thus, each electrode of the semiconductor element is electrically connected to the external electric circuit board.

[0003] This conventional wiring board is generally manufactured by a ceramic green sheet laminating method. Specifically, an organic binder and a solvent suitable for ceramic raw material powder such as aluminum oxide, silicon oxide, magnesium oxide and calcium oxide are used. The mixture is added and mixed to form a slurry, and the mixture is formed into a sheet by a well-known doctor blade method or the like to obtain a plurality of ceramic green sheets (ceramic green sheets). A punching process is performed and a metal paste to be a wiring conductor is printed and applied in a predetermined pattern. Finally, the ceramic green sheets are stacked up and down in a predetermined order to form a green ceramic molded body, and the green ceramic molded body is placed in a reducing atmosphere. Firing at a high temperature of about 1600 ° C It is fabricated me.

However, in the conventional wiring board, since ceramics such as an aluminum oxide sintered body constituting the insulating base have a hard and brittle property, the wiring boards are not connected to each other in a transfer process or an automatic line for manufacturing semiconductor devices. When the wiring board and a part of the automatic semiconductor device manufacturing line collide violently, the insulating substrate is chipped, broken, cracked, etc., and as a result, the semiconductor element cannot be housed in an airtight manner. Has a disadvantage that it cannot be operated normally and stably for a long period of time.

According to the method of manufacturing a wiring board,
When firing the green ceramic molded body, non-uniform firing shrinkage occurs in the green ceramic molded body, and deformation and dimensional variation such as warpage occur in the obtained wiring board, and each electrode of the semiconductor element and the wiring conductor are formed. Another problem is that the wiring conductor cannot be accurately and reliably electrically connected to the wiring conductor of the external electric circuit board.

Therefore, it has been proposed to replace the insulating substrate of the wiring substrate with a conventional ceramic and bond the inorganic insulating powder with a thermosetting resin.

For a wiring board using an insulating substrate formed by bonding the inorganic insulating powder with a thermosetting resin, a semi-cured insulating sheet prepared by mixing the thermosetting resin and the inorganic insulating powder is prepared. Then, the semi-cured insulating sheet is subjected to an appropriate punching process, and then a metal paste serving as a wiring conductor in which a thermosetting resin and a metal powder are mixed is printed and applied in a predetermined pattern. It is manufactured by laminating a print-coated semi-cured insulating sheet as necessary and thermally curing it at a temperature of about 100 to 300 ° C.

[0008]

However, a wiring board comprising an insulating base formed by bonding the inorganic insulating powder with a thermosetting resin and a wiring conductor formed by bonding a metal powder with a thermosetting resin, When the inorganic insulating powder constituting the insulating base is made of, for example, silicon oxide, the thermal conductivity of the silicon oxide is about 2 W / m · K, and the thermal conductivity of the thermosetting resin is about 0.1 W / m.・ Since it is about K, its thermal conductivity is as low as about 0.5 W / m · K. Therefore, when a semiconductor element which generates a large amount of heat during operation is mounted, heat generated during operation of the semiconductor element is reduced. Without being satisfactorily dissipated and removed to the outside via the insulating base, the semiconductor element becomes high in temperature due to the heat generated by the semiconductor element itself, and as a result, a disadvantage is caused in that the semiconductor element causes thermal destruction or malfunction.

In order to solve the above-mentioned disadvantage, a heat radiating member having excellent thermal conductivity such as copper, aluminum, or aluminum nitride sintered body is attached to the surface of the insulating base via an adhesive such as resin. It is conceivable to satisfactorily dissipate and remove the heat generated during operation of the semiconductor element to the outside via the heat radiating member.

However, when a heat radiating member having excellent thermal conductivity, such as copper, aluminum, or aluminum nitride sintered body, is attached to the surface of the insulating base via an adhesive such as resin, copper, aluminum, or nitrided The heat dissipating member made of an aluminum sintered body or the like has a weak chemical bonding force with an adhesive such as a resin and is hardly firmly joined to the insulating base,
Further, the coefficient of thermal expansion of the insulating substrate is about 30 × 10 ⁻⁶ / ° C. to 40.
× 10 ^-6 / ° C, whereas the coefficient of thermal expansion of copper is about 14
× 10 ^-6 / ° C, coefficient of thermal expansion of aluminum is about 23 × 1
0 ⁻⁶ / ° C., the coefficient of thermal expansion of the aluminum nitride sintered body is about 5 × 10 ⁻⁶ / ° C., which is significantly different from each other, so that the heat generated during the operation of the semiconductor element can be repeatedly applied to the insulating base and the heat radiating member. Then, the heat radiating member is separated from the insulating base due to thermal stress generated due to a difference in thermal expansion coefficient between the insulating base and the heat radiating member, and as a result, the semiconductor element mounted on the insulating base is in operation. It becomes impossible to satisfactorily dissipate the generated heat to the outside, which also causes thermal destruction and malfunction of the semiconductor element.

[0011]

According to the present invention, there is provided a wiring board comprising:
0 to 95% by weight of inorganic insulating powder and 5 to 40% by weight
And a wiring conductor formed by bonding the inorganic insulating powder with the thermosetting resin to a wiring conductor formed by bonding the metal powder with the thermosetting resin. The insulating substrate has a high thermal conductive material powder having a thermal conductivity of 100 W / m · K or more on its surface.
5% by weight and 5 to 40% by weight of a thermosetting resin,
A heat dissipating member formed by bonding the high heat conductive material powder with the thermosetting resin is attached, and the heat dissipating member is formed of a high heat conductive material having a heat conductivity of 100 W / m · K or more. The thermal conductivity of the heat dissipating member is about 25 W / m · K since the powder is made of a material obtained by bonding the powder with a thermosetting resin.
As described above, the heat generated during the operation of the semiconductor element can be satisfactorily radiated to the outside, and the heat radiation member has a coefficient of thermal expansion of 30 × 10 ⁻⁶ / ° C. to 40 × 10 ^−6.
/ ° C is substantially the same as the thermal expansion coefficient of the insulating base, and even if heat generated during operation of the semiconductor element is repeatedly applied to the insulating base and the heat radiating member, no large thermal stress is generated therebetween. The heat radiation member does not peel off from the insulating base.

Further, in the method of manufacturing a wiring board according to the present invention, there is provided a step of preparing a semi-cured insulating sheet formed by mixing a thermosetting resin and an inorganic insulating powder; A step of printing a metal paste obtained by mixing the powder with a powder on a predetermined wiring pattern; and mixing a thermosetting resin and a high thermal conductive material powder having a thermal conductivity of 100 W / m · K or more in the semi-cured insulating sheet. A step of printing and applying a high heat conductive material paste formed on a predetermined heat radiation pattern, and a step of completely thermosetting and integrating the semi-cured insulating sheet, the metal paste and the high heat conductive material paste. The semi-cured insulating sheet and the high thermal conductive material paste both contain a thermosetting resin,
Since the semi-cured insulating sheet and the high thermal conductive material paste are bonded and integrated by heat curing, the thermosetting resin contained in the semi-cured insulating sheet and the thermosetting resin contained in the high thermal conductive material paste Are chemically strongly bonded, and as a result, the insulating base and the heat radiating member are firmly joined.

[0013]

Next, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment in which the wiring board of the present invention is applied to a semiconductor element housing package for housing a semiconductor element, wherein 1 is an insulating base, and 2 is a wiring conductor.

The insulating substrate 1 has three insulating layers 1a, 1
The semiconductor element 3 is formed by laminating b and 1c, and has a concave portion A for accommodating the semiconductor element at the center of the upper surface thereof, and the semiconductor element 3 is bonded to the bottom surface of the concave portion A with an adhesive such as resin. Fixed.

The insulating layers 1a, 1 constituting the insulating substrate 1
b, 1c, for example, an inorganic insulating powder such as silicon oxide, aluminum oxide, aluminum nitride, silicon carbide, barium titanate, strontium titanate, calcium titanate, titanium oxide, zeolite, epoxy resin, polyimide resin, phenol resin, The three insulating layers 1 which are formed by bonding with a thermosetting resin such as a thermosetting polyphenylene ether resin, a polyimide amide resin, a bismaleimide triazine resin, etc.
a, 1b, and 1c are formed by bonding inorganic insulating powder with a thermosetting resin such as an epoxy resin having excellent toughness, so that even if an external force is applied to the insulating base 1, the insulating substrate 1 is insulated by the external force. Chipping, cracking, cracking and the like do not occur in the base 1.

Incidentally, three insulating layers 1a, 3a constituting an insulating base 1 formed by bonding the inorganic insulating powder with a thermosetting resin.
1b and 1c, when the content of the inorganic insulating powder contained therein is less than 60% by weight, the thermal expansion coefficient of the insulating base 1 is significantly different from the thermal expansion coefficient of the semiconductor element 3; Generates heat during operation, and when the heat is applied to both the semiconductor element 3 and the insulating base 1, a large thermal stress is generated between the two due to a difference in the coefficient of thermal expansion between the two. The semiconductor element 3 peels off from the insulating base 1 or the semiconductor element 3 is cracked or chipped. Therefore, the insulating layers 1a, 1b, 1
As for c, the amount of the inorganic insulating powder contained therein is specified in the range of 60 to 95% by weight.

The insulating substrate 1 is made of a metal powder such as copper, silver, gold, etc., from the periphery of the concave portion A to the outer peripheral portion of the lower surface thereof by epoxy resin, polyimide resin, phenol resin, thermosetting polyphenylene ether resin, polyimide amide resin. And a wiring conductor 2 bonded by a thermosetting resin such as a bismaleimide triazine resin.

The wiring conductor 2 serves to electrically connect each electrode of the semiconductor element 3 to an external electric circuit. Each electrode of the semiconductor element 3 is located at a position around the concave portion A of the insulating base 1. A portion electrically connected via the bonding wire 4 and a portion led out to the outer peripheral portion of the lower surface of the insulating base 1 is electrically connected to an external electric circuit.

The metal powder contained in the wiring conductor 2 is as follows:
The wiring conductor 2 acts to impart conductivity to the wiring conductor 2.
If the content is less than 70% by weight, the electrical resistance of the wiring conductor 2 is high, and if it exceeds 95% by weight, the metal powder is firmly bound with a thermosetting resin and a predetermined wiring conductor 2 is formed.
Tends to be difficult to form. Therefore, the amount of the metal powder contained in the wiring conductor 2 is reduced by 7%.
It is preferable to set the range of 0 to 95% by weight.

The thermosetting resin contained in the wiring conductor 2 serves to bind the metal powder contained in the wiring conductor 2 and to adhere the wiring conductor 2 to the insulating base 1. If the content of the metal powder 2 is less than 5% by weight, it tends to be difficult to form the wiring conductor 2 by firmly bonding the metal powders to each other, and if it exceeds 30% by weight, the electrical resistance of the wiring conductor 2 is large. It tends to be something. Therefore, the content of the thermosetting resin contained in the wiring conductor 2 is preferably in the range of 5 to 30% by weight.

The wiring conductor 2 is preferably provided with a metal having excellent corrosion resistance, such as nickel or gold, and a good conductivity, having a thickness of 1.0 to 20.0 μm by a plating method. Oxidation and corrosion of the wiring conductor 2 can be effectively prevented, and the wiring conductor 2 and the bonding wire 4
Can be firmly and electrically connected. Therefore, it is preferable that the wiring conductor 2 is coated with a metal having excellent corrosion resistance, such as nickel or gold, and a good conductivity by a plating method to a thickness of 1.0 to 20.0 μm on the exposed surface.

Further, the insulating base 1 has copper on its lower surface,
60 to 95% by weight of high thermal conductive material powder having a thermal conductivity of 100 W / m · K or more such as silver, aluminum, aluminum nitride sintered body, epoxy resin, polyimide resin, bismaleimide triazine resin, phenol resin, thermosetting polyphenylene A heat dissipating member 5 made of a thermosetting resin such as an ether resin or the like in an amount of 5 to 40% by weight and formed by bonding the high heat conductive material powder with the thermosetting resin is attached.

The heat dissipating member 5 functions to satisfactorily dissipate the heat generated during operation of the semiconductor element 3 to the outside, and has a heat conductivity of 60 to 95% by weight of a high heat conductive material powder having a heat conductivity of 100 W / m · K or more. And 5 to 40% by weight of a thermosetting resin, and the high thermal conductive material powder is bonded with the thermosetting resin, so that the thermal conductivity becomes as large as about 25 W / m · K or more. Its thermal expansion coefficient is about 30 ×
10 ⁻⁶ / ° C. to 40 × 10 ⁻⁶ / ° C., which is close to the coefficient of thermal expansion of the insulating substrate 1. As a result, heat generated when the semiconductor element 3 is operated can be radiated to the outside very well. Even if the heat generated during operation of the semiconductor element 3 is applied to both the insulating base 1 and the heat radiating member 5, no large thermal stress is generated due to the difference in the thermal expansion coefficient between the two. The heat radiating member is insulated by the stress in the insulating base 1
The semiconductor element 3 can always be operated normally and stably without being separated from the semiconductor element 3.

The high heat conductive material powder contained in the heat radiating member 5 has a function of imparting a large thermal conductivity to the heat radiating member 5, and when the heat conductivity is less than 100 W / m · K, the heat radiating member 5 has a high thermal conductivity. , The heat generated during the operation of the semiconductor element 3 is difficult to satisfactorily dissipate to the outside, resulting in thermal destruction and malfunction of the semiconductor element 3. The danger becomes great. Therefore, the high thermal conductive material powder contained in the heat radiating member 5 is limited to those having a thermal conductivity of 100 W / m · K or more.

When the content of the high thermal conductive material powder in the heat radiating member 5 is less than 65% by weight, the heat conductivity of the heat radiating member 5 may be as large as about 25 W / m · K or more. It becomes difficult to satisfactorily dissipate the heat generated during the operation of the semiconductor element 3 to the outside, and there is a great risk that the semiconductor element 3 will be damaged by heat or malfunction. %, It becomes difficult to form the predetermined heat radiating member 5 by firmly bonding the high thermal conductive material powder with the thermosetting resin. Therefore, the content of the high thermal conductive material powder contained in the heat radiating member 5 is 65 to 95% by weight in the heat radiating member 5.
Is limited to the range.

Further, if the thermosetting resin contained in the heat radiating member 5 is substantially the same as the thermosetting resin contained in the insulating base 1, the thermal expansion coefficient of the heat radiating member 5 is reduced. The thermal expansion coefficient can be made very close to the coefficient of thermal expansion of the base 1, and the heat radiation member 5 can be very firmly adhered to the insulating base 1. Therefore, the thermosetting resin contained in the heat radiating member 5 is preferably substantially the same as the thermosetting resin contained in the insulating base 1.

Thus, according to the wiring board of the present invention, the semiconductor element 3 is bonded and fixed to the bottom surface of the recess A of the insulating base 1 with an adhesive such as a resin, and each electrode of the semiconductor element 3 is bonded with the bonding wire 4. It is electrically connected to the wiring conductor 2, and finally, the lid 6 is joined to the upper surface of the insulating base 1 via a sealing material made of resin or the like, and the semiconductor is placed inside the container including the insulating base 1 and the lid 5. The semiconductor device as a product is completed by housing the element 3 in an airtight manner.

Next, a method of manufacturing a wiring board used in the package for housing a semiconductor element will be described.

First, as shown in FIG. 2A, three semi-cured insulating sheets 11a, 11b and 11c are prepared by bonding inorganic insulating powder with a thermosetting resin.

The three semi-cured insulating sheets 11a, 11
b and 11c are formed by bonding an inorganic insulating powder with a thermosetting resin, and have a particle size of, for example, 0.1 to
A paste obtained by adding and mixing an epoxy resin and an imidazole-based curing agent to silicon oxide powder of about 100 μm is formed into a sheet by using a sheet forming method such as a doctor blade method, and the sheet is formed at a temperature of 25 to 150 ° C. 1-60
Produced by heating and semi-curing for a minute.

The semi-cured insulating sheets 11a, 11a
b and 11c are semi-cured so that their hardness is 40 to 90 as specified in Type A measurement according to JIS 7215 and 6301, and as described later, three semi-cured insulating sheets 11a, 11b and 11c When semi-cured insulating sheets 11a, 11b, 11c are not deformed or cracked when punching or printing and applying a metal paste to be wiring conductor 2 or a high heat conductive material paste to be heat radiating member 5, In addition, punching and printing of a metal paste and a high thermal conductive material paste can be performed reliably, and as a result, a desired wiring board can be accurately and reliably manufactured. Therefore, the semi-cured insulating sheets 11a, 1
It is preferable that the hardness of 1b and 11c is set in the range of 40 to 90 as the hardness specified in the type A measurement of JIS7215,6301.

Next, as shown in FIG. 2B, two semi-cured insulating sheets 11a, 11b among the three semi-cured semi-cured insulating sheets 11a, 11b are provided with openings 12a that form recesses A. , 12b to two semi-cured insulating sheets 11
b, 11c through-hole 13 for routing wiring conductor 2
b and 13c are formed respectively.

The openings 12a and 12b and the through holes 13
b, 13c are semi-cured insulating sheets 11a, 11b, 11
The semi-cured insulating sheets 11a, 11b, and 11c are formed by subjecting each of the semi-cured insulating sheets 11a, 11b, and 11c to a hole having a predetermined shape.

Next, as shown in FIG. 2C, the upper and lower surfaces of the semi-cured insulating sheets 11b and 11c and the through holes 13b,
13c, a metal paste 21 to be the wiring conductor 2 is printed and applied to a predetermined wiring pattern by using a conventionally known screen printing method and filling method, and the heat radiation member 5 is formed on the lower surface of the semi-cured insulating sheet 11c. The high thermal conductive material paste 22 is applied by printing using a screen printing method, and thereafter, these are applied at a temperature of about 25 to 150 ° C. for 1 to 6 hours.
The metal paste 21 and the high heat conductive material paste 22 are semi-cured by heating for 0 minutes.

The metal paste 21 serving as the wiring conductor 2 is, for example, a powder of copper having a particle size of about 0.1 to 20 μm or an epoxy resin such as a bisphenol A type epoxy resin, a novolak type epoxy resin, and a glycidyl ester type epoxy resin. A curing agent such as an amine-based curing agent, an imidazole-based curing agent, and an acid anhydride-based curing agent is added and mixed to form a paste.

The high thermal conductive material paste 22 serving as the heat radiating member 5 has, for example, a thermal conductivity of 100 W / m ·
K or more of the aluminum nitride sintered body is pulverized to a particle size of 0.
Aluminum nitride sintered powder in the form of powder having a particle size of about 1 to 20 μm is added to an epoxy resin such as bisphenol A type epoxy resin, novolak type epoxy resin, glycidyl ester type epoxy resin, and the like, an amine curing agent, an imidazole curing agent, an acid anhydride. A paste obtained by adding and mixing a curing agent such as a system curing agent is used.

Finally, the three semi-cured insulating sheets 11a, 11b, and 11c are vertically laminated under pressure and heated at a temperature of about 80 to 300 ° C. for about 10 seconds to 24 hours. The insulating base 1 as shown in FIG. 1 is obtained by completely thermosetting the metal pastes 11a, 11b, 11c, the metal paste 21, and the high thermal conductive material paste 22.
A wiring board in which the wiring conductor 2 and the heat radiating member 5 are integrally attached is completed.

In this case, according to the method of manufacturing a wiring board of the present invention, the semi-cured insulating sheets 11a, 11b, 11c
And the metal paste 21 and the high thermal conductive material paste 22
There is almost no shrinkage at the time of thermosetting, and therefore, there is no deformation or dimensional variation in the obtained wiring board, and a wiring board capable of accurately connecting the semiconductor element 3 and the wiring conductor 2 Further, the thermosetting resins contained in the semi-cured insulating sheets 11a, 11b, 11c, the metal paste 21, and the high heat conductive material paste 22 are chemically strongly bonded to each other by a curing reaction. The wiring conductor 2 and the heat radiating member 5 are firmly adhered to the base 1, and the wiring conductor 2 and the heat radiating member 5 do not peel off from the insulating base 1 in the obtained wiring board, and therefore, the heat generated when the semiconductor element 3 is operated. Can be always satisfactorily radiated to the outside via the heat radiating member 5 to enable the semiconductor element 3 to operate normally and stably.

Further, the cured insulating sheets 11a, 11
When the thermosetting resin contained in the b and 11c and the thermosetting resin contained in the high thermal conductive material paste 22 are substantially the same resin, the cured insulating sheets 11a and
1b, 11c, the metal paste 21, and the high thermal conductive material paste 22 are completely thermally cured to form the wiring conductor 2 on the insulating base 1.
In addition, when the heat radiating member 5 is attached and integrated, the heat radiating member 5 can be extremely firmly and easily attached and integrated to the insulating base 1. Therefore, the cured insulating sheets 11a, 11
It is preferable that the thermosetting resin contained in b and 11c and the thermosetting resin contained in the high thermal conductive material paste 22 are substantially the same resin.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention. The present invention does not have a heat transfer means between the bottom surface of the concave portion A of the insulating base 1 and the heat radiating member 5 for improving the thermal conductivity between the bottom surface of the concave portion A and the heat radiating member 5. The wiring board of FIG.
The thermal via 7 penetrates from the bottom surface of the concave portion A to the lower surface of the insulating base 1 and reaches the heat radiation member 5 and is filled with a high heat conductive material.
In this case, the heat generated during the operation of the semiconductor element 3 is very well transmitted to the heat radiating member 5 via the high thermal conductive material in the thermal via 7, and the transmitted heat is radiated. It is more preferable because it is efficiently radiated to the outside via the member 5. The high thermal conductive material filled in the thermal via 7 is the same material as the heat radiating member 5, specifically, the thermal conductivity of copper, aluminum, silver, aluminum nitride sintered body or the like is 100 W / m · K or more. 60 to 95% by weight of high thermal conductive material powder and epoxy resin, polyimide resin, bismaleimide triazine resin, phenol resin,
A high heat conductive material composed of 5 to 40% by weight of a thermosetting resin such as a thermosetting polyphenylene ether resin, wherein the high heat conductive material powder is bonded with the thermosetting resin is preferably used. The semi-cured insulating sheet 11c serving as the first insulating layer 1c was provided with a through hole serving as the thermal via 7, and a high heat conductive material powder and a thermosetting resin were mixed in the through hole serving as the thermal via 7. By filling a high thermal conductive material paste and thermally curing it together with the semi-cured insulating sheets 11a, 11b, 11c serving as the insulating base 1, the metal paste 21 serving as the wiring conductor 2, and the high thermal conductive material paste 22 serving as the heat radiating member 5. Insulating substrate 1
A wiring board having a thermal via 7 penetrating from the bottom surface of the concave portion A to the lower surface of the insulating base 1 and reaching the heat dissipation member 5 is manufactured.

In the above embodiment, the case where the wiring board of the present invention is applied to a package for housing a semiconductor element for housing a semiconductor element has been described as an example. However, the wiring board may be used for other purposes such as a hybrid integrated circuit. It may be applied to a wiring board to be used.

Further, in the above-described embodiment, a wiring board is manufactured by laminating three semi-cured insulating sheets. However, one, two, or four or more semi-cured insulating sheets are used. A wiring board may be manufactured.

Further, in the above-described embodiment, the insulating base is composed of the inorganic insulating powder and the thermosetting resin. However, the insulating base may further include glass fiber, carbon fiber, aramid fiber, alumina fiber, titanic acid, and the like. Short fibers such as potassium whiskers and aluminum borate whiskers may be blended.

Furthermore, in the above-described embodiment, the wiring conductor is formed by bonding metal powder with a thermosetting resin. It may be formed by bonding metal powders together.In this case, a low-melting-point metal powder made of, for example, tin-lead solder or the like is mixed as a low-melting-point metal in a metal paste to be a wiring conductor. After printing and applying to the semi-cured insulating sheet, a method is adopted in which heat is applied thereto to melt the low melting point metal powder, and the metal powder is bonded by the melted low melting point metal.

[0045]

According to the wiring board of the present invention, since the insulating base is formed by bonding the inorganic insulating powder with the thermosetting resin having excellent toughness, the wiring boards or the wiring board and the semiconductor device are formed. No chipping, cracking, cracking, etc. will occur in the insulating base even if a part of the semiconductor device collides violently.
And it can be operated stably.

According to the wiring board of the present invention, the heat radiating member is composed of 60 to 95% by weight of a high heat conductive material powder having a thermal conductivity of 100 W / m · K or more and 5 to 40% by weight of a thermosetting resin. Since the high thermal conductive material powder is bonded by the thermosetting resin, its thermal conductivity is about 25 W / m · K.
The thermal expansion coefficient is about 3
0 to 40 × 10 −6 / ° C., which is close to the coefficient of thermal expansion of the insulating substrate. As a result, the heat generated during operation of the semiconductor element can be very effectively radiated to the outside and removed, and the semiconductor element operates. Even if the heat generated at the time is applied to both the insulating base and the heat radiating member, no large thermal stress is generated due to the difference in the thermal expansion coefficient between the two, and therefore the heat radiating member is separated from the insulating base by the stress. Therefore, the semiconductor element can always be operated normally and stably.

Further, according to the method for manufacturing a wiring board of the present invention, a semi-cured insulating sheet formed by mixing a thermosetting resin and an inorganic insulating powder, and a metal formed by mixing a thermosetting resin and a metal powder. The wiring board is manufactured by thermosetting the paste, thermosetting resin and high heat conductive material paste,
The semi-cured insulating sheet, the metal paste, and the high thermal conductive material paste hardly shrink during thermal curing, and therefore, the resulting wiring board is free from deformation and dimensional variation. It is possible to provide a wiring board that can accurately connect with a conductor,
Furthermore, since the thermosetting resins contained in the semi-cured insulating sheet, the metal paste, and the high heat conductive material paste are chemically bonded to each other by a curing reaction, the wiring conductor and the heat radiating member are extremely firmly adhered to the insulating base. In the obtained wiring board, the wiring conductor and the heat radiating member do not peel off from the insulating base, so that the heat generated during the operation of the semiconductor element is always satisfactorily radiated to the outside through the heat radiating member so that the semiconductor element is normal and stable And a wiring board that can be operated at a time.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment in which a wiring board of the present invention is applied to a package for housing a semiconductor element.

FIG. 2 is a cross-sectional view of each process for explaining the method for manufacturing a wiring board of the present invention.

FIG. 3 is a sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulating base 2 ... Wiring conductor 5 ... Heat radiating member 11 ... Semi-hardened insulating sheet 21 ... Metal paste 22 ... High heat conductive material paste

Claims (4)

[Claims] An inorganic insulating powder of 60 to 95% by weight and 5
To 40% by weight of a thermosetting resin, and a wiring conductor formed by bonding the metal powder with the thermosetting resin to an insulating base formed by bonding the inorganic insulating powder with the thermosetting resin. A wiring board, wherein the insulating base comprises, on the surface thereof, 60 to 95% by weight of a high thermal conductive material powder having a thermal conductivity of 100 W / m · K or more and 5 to 40% by weight of a thermosetting resin. A wiring board, on which a heat radiating member formed by bonding a material powder with the thermosetting resin is attached. 2. The wiring board according to claim 1, wherein the thermosetting resin of the insulating base and the thermosetting resin of the heat radiation member are substantially the same resin. 3. A step of preparing a semi-cured insulating sheet comprising a mixture of a thermosetting resin and an inorganic insulating powder; and a metal paste comprising mixing the thermosetting resin and a metal powder with the semi-cured insulating sheet. Printing on a predetermined wiring pattern, and applying a thermosetting resin and a thermal conductivity of 100 to the semi-cured insulating sheet.
A step of printing and applying a high heat conductive material paste formed by mixing a high heat conductive material powder of W / m · K or more in a predetermined heat radiation pattern, and completely connecting the semi-cured insulating sheet, the metal paste and the high heat conductive material paste. And b. A step of thermosetting and integrating the wiring board. 4. The thermosetting resin contained in the semi-cured sheet and the thermosetting resin contained in the high heat conductive material paste are substantially the same resin. Method of manufacturing a wiring board.