JPH08288596A - Wiring board and manufacturing method thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a wiring board capable of effectively preventing the occurrence of chips, cracks, and the like and reliably electrically connecting a semiconductor element or the like to an external electric circuit. [Structure] An insulating substrate 1 comprising 60 to 95% by weight of an inorganic insulating powder and 5 to 40% by weight of a thermosetting resin, wherein the inorganic insulating powder is bonded by the thermosetting resin.
The wiring conductor 2 in which metal powder was bonded with an epoxy-modified acrylate resin was applied.

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 semiconductor element housing package for housing semiconductor elements, a hybrid integrated circuit board and the like.

[0002]

2. Description of the Related Art Hitherto, as a wiring board, for example, a wiring board used in a semiconductor element housing package for housing a semiconductor element, a laminated ceramic wiring board capable of relatively high-density wiring has been widely used. This wiring board is made of ceramics such as aluminum oxide sintered body and has an insulating base having a recess for accommodating a semiconductor element in the center of the upper surface thereof, and tungsten, molybdenum, etc. led out from the periphery of the recess of the insulating base to the lower surface. And a wiring conductor made of a refractory metal powder, the semiconductor element is adhered and fixed to the bottom surface of the recess of the insulating substrate via an adhesive such as glass, resin, or brazing material, and each electrode of the semiconductor element is fixed. For example, it is electrically connected to a wiring conductor through an electrical connection means such as a bonding wire, and then a glass cover is formed on the upper surface of the insulating base so as to cover the recess of the insulating base. , A resin, a brazing material, etc., are bonded together, and the semiconductor element is hermetically housed in the recess of the base body. To become.

This conventional wiring board is generally manufactured by a ceramic green sheet laminating method. Specifically, aluminum oxide, silicon oxide, magnesium oxide,
A plurality of ceramic green sheets are obtained by adding a suitable organic binder to a ceramic raw material powder such as calcium oxide, a solvent and the like to form a slurry and making it into a sheet shape by adopting a conventionally known doctor blade method, Thereafter, the ceramic green sheet is subjected to appropriate punching processing, a metal paste to be a wiring conductor is printed and applied in a predetermined pattern, and finally the ceramic green sheets are laminated vertically in a predetermined order to form a ceramic molded body. It is manufactured by firing the ceramic green body at a high temperature of about 1600 ° C. in a reducing atmosphere.

[0004]

However, in this conventional wiring board, since the ceramics such as the aluminum oxide sintered body forming the insulating substrate have the property of being hard and brittle, an automatic line for the carrying process and the semiconductor device manufacturing is provided. Etc., when the wiring boards collide with each other or between the wiring boards and a part of the semiconductor device manufacturing automatic line, a crack, crack, crack or the like occurs in the insulating substrate, and as a result, the semiconductor element can be housed in an airtight manner. Therefore, there is a drawback that the semiconductor element cannot be operated normally and stably for a long period of time.

Further, according to the method for manufacturing a wiring board, when firing the ceramic green body, uneven firing shrinkage occurs in the ceramic green body due to the variation in the density of the ceramic raw material powder in each ceramic green sheet. There is also a drawback that the resulting wiring board is deformed due to warpage or the like and the dimensions are varied, and if the deformation or the variations are large, the wiring conductor is broken.

[0006]

SUMMARY OF THE INVENTION The present invention has been devised in view of the drawbacks of the conventional semiconductor device housing package, and its purpose is to effectively prevent the occurrence of chipping or cracking due to the application of impact force, It is an object of the present invention to provide a wiring board that can normally and stably operate a semiconductor element housed inside for a long period of time.

Another object of the present invention is to reduce deformation such as warpage and variation in dimensions, effectively prevent disconnection of wiring conductors, and reliably electrically connect electrodes such as semiconductor elements to an external electric circuit. An object of the present invention is to provide a method of manufacturing a wiring board that can be manufactured.

[0008]

A wiring board according to the present invention comprises 6
0 to 95% by weight of inorganic insulating powder and 5 to 40% by weight
A thermosetting resin, and a wiring conductor formed by bonding a metal powder with an epoxy-modified acrylate resin is adhered to an insulating substrate having the inorganic insulating powder bonded with the thermosetting resin. To do.

Further, the method for manufacturing a wiring board of the present invention comprises the steps of preparing a precursor sheet formed by mixing a curable resin precursor and an inorganic insulating powder, and adding an epoxy-modified acrylate resin to the precursor sheet. A step of printing a metal paste formed by mixing a metal powder with a metal powder in a predetermined pattern, a step of semi-curing the metal paste printed in the predetermined pattern with ultraviolet light, the precursor sheet and a predetermined pattern And a step of thermally curing the metal paste.

[0010]

According to the wiring board of the present invention, since the insulating substrate is formed by bonding the inorganic insulating powder with the thermosetting resin having excellent toughness, the wiring boards are connected to each other or the wiring boards and the semiconductor device manufacturing automatic line. Even if it collides violently with a part of the above, the insulating substrate will not be chipped, cracked, or cracked.

The wiring board of the present invention is obtained by thermosetting a precursor sheet formed by mixing a curable resin precursor and an inorganic insulating powder, and a metal paste formed by mixing an epoxy-modified acrylate resin and a metal powder. Since there is no firing process, deformation and dimensional variation due to uneven firing shrinkage do not occur, and as a result, there is no disconnection in the wiring conductor, and there is no semiconductor through the wiring conductor. It is possible to reliably electrically connect the electrodes of the element or the like to the external electric circuit.

Further, in the wiring board of the present invention, the metal paste printed on the precursor sheet made by mixing the curable resin precursor and the inorganic insulating powder is once semi-cured by ultraviolet rays, so that the precursor sheet or the like is obtained. No deformation or the like occurs in the wiring conductor during thermosetting, the shape at the time of printing can be maintained, and the wiring conductor can be easily densified.

[0013]

The present invention will now 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 substrate and 2 is a wiring conductor. The wiring substrate is formed by attaching the wiring conductor 2 to the insulating substrate 1.

The insulating substrate 1 comprises three insulating substrates 1a and 1a.
It is formed by stacking b and 1c, and has a recess 1d for accommodating a semiconductor element in the center of the upper surface thereof, and the semiconductor element 3 is provided on the bottom surface of the recess 1d via an adhesive such as resin. Adhesively fixed.

The three insulating substrates 1a, 1b and 1c constituting the insulating base 1 are made of an inorganic insulating powder such as silicon oxide, aluminum oxide, aluminum nitride, silicon carbide, barium titanate, epoxy resin or polyimide resin. It is formed by bonding with thermosetting resin of
Three insulating substrates 1a, 1b, 1c constituting the insulating base 1
Since each of them is formed by binding the inorganic insulating powder with a thermosetting resin having excellent toughness, even if an external force is applied to the insulating base 1, the insulating base 1 is applied by the external force.
There is no chipping, cracking, or cracking.

In addition, three insulating substrates 1 constituting an insulating substrate 1 formed by bonding the inorganic insulating powders with a thermosetting resin.
a, 1b, and 1c have an inorganic insulating powder content of 60% by weight.
When it is less than the above, the coefficient of thermal expansion of the insulating substrate 1 greatly differs from the coefficient of thermal expansion of the semiconductor element 3, the semiconductor element 3 emits heat during operation, and the heat is applied to both the semiconductor element 3 and the insulating substrate 1. Then, a large thermal stress is generated between them due to the difference in thermal expansion coefficient between the two, and the semiconductor element 3 is separated from the insulating substrate 1 due to the large thermal stress, or the semiconductor element 3 is cracked or chipped. I will end up. On the other hand, if it exceeds 95% by weight, the inorganic insulating powder cannot be completely bonded with the thermosetting resin, and the predetermined insulating substrates 1a, 1b, 1c cannot be obtained. Therefore, the insulating substrates 1a, 1b, 1c constituting the insulating base 1 are specified such that the amount of the inorganic insulating powder contained therein is in the range of 60 to 95% by weight.

A wiring conductor 2 is adhered and formed from the periphery of the recess 1d to the lower surface of the insulating substrate 1. The wiring conductor 2 is formed by bonding a metal powder of copper, silver, gold or the like with an epoxy-modified acrylate resin. It is made of things.

The wiring conductor 2 functions to connect the electrode of the semiconductor element 3 to an external electric circuit, and the recess 1 of the insulating base 1 is formed.
d Each electrode of the semiconductor element 3 is electrically connected to the wiring conductor 2 located in the peripheral portion via the bonding wire 4, and the portion led out to the lower surface of the insulating substrate 1 is electrically connected to the external electric circuit. To be done.

The wiring conductor 2 formed by binding the metal powder with an epoxy-modified acrylate resin is used if the content of the metal powder is less than 70% by weight.
When the electric resistance value is higher than 95% by weight, it becomes difficult to bond the metal powder with the epoxy modified acrylate resin to form the predetermined wiring conductor 2. Therefore, it is preferable that the content of the metal powder in the wiring layer 2 is in the range of 70 to 95% by weight.

The wiring conductor 2 is formed by depositing a metal having excellent corrosion resistance such as nickel or gold on the exposed surface by a plating method to a thickness of 1 to 20 μm. Oxidation and corrosion can be effectively prevented, and the bonding wire 4 can be firmly electrically connected to the wiring conductor 2. Therefore, the wiring conductor 2
It is preferable that a metal having excellent corrosion resistance, such as nickel or gold, and having good conductivity is deposited on the exposed surface by a plating method to a thickness of 1 to 20 μm.

Thus, according to the above wiring board, the semiconductor element 3 is adhered and fixed to the bottom surface of the concave portion 1a of the insulating substrate 1 with an adhesive such as resin, and each electrode of the semiconductor element 3 is wired with the bonding wire 4. After electrically connecting to the conductor 2, the lid 5 is joined to the upper surface of the insulating base 1 via a sealing material made of resin or the like, and the semiconductor element is placed inside the container made up of the insulating base 1 and the lid 5. A semiconductor device as a product is completed by hermetically containing 3 therein.

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

First, as shown in FIG. 2 (a), three precursor sheets 11a, 11b and 11c are prepared. The three precursor sheets 11a, 11b, and 11c are formed by bonding inorganic insulating powders with a thermosetting resin precursor. For example, silicon oxide powders having a particle size of 0.1 to 100 μm are mixed with bisphenol. A type epoxy resin, novolac type epoxy resin, glycidyl ester type epoxy resin and other epoxy resins and amine type curing agents, imidazole type curing agents, acid anhydride type curing agents and other curing agents are added and mixed to form a paste, Then, the paste is formed into a sheet and is heated at a temperature of about 25 to 100 ° C. for 1 to 60 minutes to be semi-cured.

Next, as shown in FIG. 2B, the recess 1 for accommodating the semiconductor element 3 in the two precursor sheets 11a, 11b among the three precursor sheets 11a, 11b, 11c.
The openings A and A ′ that become a are two precursor sheets 11b,
Through holes B and B'for routing the wiring conductor 2 are formed in 11c.

The openings A, A'and the through holes B, B'are formed by subjecting the precursor sheets 11a, 11b, 11c to a well-known punching process to obtain the precursor sheets 11a, 11b, 11c.
It is formed by drilling a hole of a predetermined shape in each of c.

Next, as shown in FIG. 2 (c), a metal paste 12 to be the wiring conductor 2 is formed on the upper and lower surfaces of the precursor sheets 11b and 11c and in the through holes B and B'by a conventionally known screen printing method. A predetermined pattern is printed and applied, and at the same time, it is irradiated with ultraviolet rays to be semi-cured.

As the metal paste 12, for example, a copper powder having a particle diameter of 0.1 to 20 μm as a metal powder to which an epoxy-modified acrylate resin is added and mixed to form a paste is used.

The metal paste 12 printed and applied on the precursor sheets 11b and 11c is semi-cured by irradiation of ultraviolet rays, and therefore, the three precursor sheets 11 to be described later.
When a, 11b, 11c and the metal paste 12 printed and applied in a predetermined pattern on each of the precursor sheets are thermoset to obtain a wiring board in which the wiring conductor 2 is adhered to the insulating substrate 1,
No deformation or the like occurs in the pattern of the metal paste 12, and as a result, even if a large number of patterns based on the metal base 12 are brought close to and printed on the precursor sheets 11b and 11c, the adjacent patterns come into contact with each other and electrically. It is possible to form a pattern of the metal paste 12 on the precursor sheets 11b and 11c with high density without causing a short circuit.

The metal paste 12 printed and applied on the precursor sheets 11b and 11c has an integrated amount of ultraviolet rays of 200.
A semi-cured state is obtained by irradiating with ultraviolet rays of ˜1600 mJ / cm ² .

Finally, the three precursor sheets 11
a, 11b, 11c are stacked on top of each other and heated at a temperature of about 80 to 300 ° C. for about 10 seconds to 24 hours to form a predetermined pattern on the precursor sheets 11a, 11b, 11c and the precursor sheets 11b, 11c. By completely thermosetting the metal paste 12 printed and applied to
A wiring board used in a package for housing a semiconductor device, in which the wiring conductor 2 is adhered to the insulating substrate 1 as shown in (3), is completed. In this case, the precursor sheets 11a, 11b, 11
c and the metal paste 12 hardly shrink during thermosetting, so that the obtained wiring board is never deformed or the dimensions are not varied, and the wiring conductor is not broken. Through this, the electrodes of the semiconductor element or the like can be reliably electrically connected to the external electric circuit.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the scope of the present invention. For example, in the above-mentioned embodiments, the wiring board of the present invention can be applied. Although the description has been given by taking as an example the case where the above is applied to a semiconductor element housing package for housing a semiconductor element, this may be applied to a hybrid integrated circuit board or the like.

In the above-mentioned embodiment, the wiring board is manufactured by laminating the three precursor sheets. However, the wiring board is manufactured by using one, two, or four or more precursor sheets. May be.

[0033]

According to the wiring board of the present invention, since the insulating substrate is formed by bonding the inorganic insulating powder with the thermosetting resin having excellent toughness, the wiring boards are manufactured together or the wiring board and the semiconductor device are manufactured. Even if a part of the automatic line collides violently, the insulating substrate will not be chipped, cracked, or cracked.

The wiring board of the present invention is obtained by thermosetting a precursor sheet made by mixing a curable resin precursor and an inorganic insulating powder, and a metal paste made by mixing an epoxy-modified acrylate resin and a metal powder. Since there is no firing process, deformation and dimensional variation due to uneven firing shrinkage do not occur, and as a result, there is no disconnection in the wiring conductor, and there is no semiconductor through the wiring conductor. It is possible to reliably electrically connect the electrodes of the element or the like to the external electric circuit.

Further, in the wiring board of the present invention, the metal paste printed on the precursor sheet formed by mixing the curable resin precursor and the inorganic insulating powder is once semi-cured by ultraviolet rays, so that the precursor sheet or the like is obtained. No deformation or the like occurs in the wiring conductor during thermosetting, the shape at the time of printing can be maintained, and the wiring conductor can be easily densified.

[Brief description of drawings]

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

2A to 2C are cross-sectional views for each step for explaining the method for manufacturing a wiring board according to the present invention.

[Explanation of symbols]

 Insulation bases 1a, 1b, 1c ... Insulation substrate 2 ... Wiring conductors 11a, 11b, 11c・ ・ ・ Precursor sheet 12 ・ ・ ・ ・ ・ ・ ・ ・ ・ Metal paste

Claims (2)

[Claims] 1. 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 a metal powder with an epoxy-modified acrylate resin is adhered to an insulating substrate having the inorganic insulating powder bonded with the thermosetting resin. Wiring board. 2. A step of preparing a precursor sheet formed by mixing a thermosetting resin precursor and an inorganic insulating powder, and mixing the epoxy sheet with an epoxy-modified acrylate resin and a metal powder. A step of printing the formed metal paste in a predetermined pattern, a step of semi-curing the metal paste printed in the predetermined pattern with ultraviolet rays, and a step of thermally curing the precursor sheet and the metal paste printed in the predetermined pattern A method of manufacturing a wiring board.