JP3297574B2 - Wiring board and method of manufacturing the same - Google Patents

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 housed in a central portion of an upper surface thereof. And a wiring conductor made of a refractory metal powder such as tungsten or molybdenum which is 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 electrically connected to wiring conductors via electrical connection means such as a bonding wire, and then the insulating base is adhered and fixed by an adhesive such as glass, resin, or brazing material. A lid made of metal, ceramics, or the like is placed on the top surface of the insulating base with a sealing material such as glass, resin, brazing material, etc. A semiconductor device as a product is obtained by joining the semiconductor elements in a concave portion of the insulating base in an airtight manner, and a portion of the wiring conductor led out to the bottom of the concave portion of the insulating base is connected to the wiring conductor of the external electric circuit board. Each electrode of the element is electrically connected to the external electric circuit board.

Incidentally, the wiring board is generally manufactured by a ceramic green sheet laminating method, and specifically, aluminum oxide, silicon oxide, magnesium oxide,
A ceramic raw material powder such as calcium oxide is mixed with an appropriate organic binder, a solvent, and the like to form a slurry, which is formed into a sheet by employing a conventionally known doctor blade method, thereby obtaining a plurality of ceramic green sheets. Thereafter, the ceramic green sheet is subjected to a suitable punching process and a metal paste to be a wiring conductor is printed and applied in a predetermined pattern, and finally, the ceramic green sheets are stacked up and down in a predetermined order to form a green ceramic molded body. It is manufactured by sintering and firing the ceramic forming 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 constituting the insulating base have a hard and brittle property, the automatic wiring of the transfer process and the semiconductor device manufacturing is difficult. When the wiring boards collide with each other or the wiring board and a part of the semiconductor device manufacturing automatic line violently collide with each other, chips, cracks, cracks, etc. occur in the insulating base, and as a result, the semiconductor element can be housed in an airtight manner. In addition, the semiconductor device cannot operate normally and stably for a long period of time.

According to the method of manufacturing a wiring board,
When firing the ceramic forming body, uneven firing shrinkage occurs in the ceramic forming body, resulting in deformation and dimensional variation such as warpage of the obtained wiring board, and as a result, each electrode of the semiconductor element and the wiring conductor Or the wiring conductor and the wiring conductor of the external electric circuit board are difficult to accurately and reliably electrically connect.

[0006]

Wiring board of the present invention, in order to solve the problem] is composed by an inorganic insulator powder bonded with a thermosetting resin, wherein
Combine inorganic insulator powder with the precursor of the thermosetting resin
Precursor sheet is semi-cured and multiple sheets are laminated
The thermosetting resin obtained by thermosetting the inorganic insulating powder
The insulating substrate an insulating substrate formed by laminating a plurality of insulating substrates joined by the precursor sheet together with the semi-cured
A wiring conductor formed by bonding a thermosetting resin to a copper powder whose surface is coated with aluminum or nickel.

Further, the wiring board of the present invention is characterized in that the amount of the inorganic insulating powder contained in the insulating base is 60% by weight to 95% by weight based on the total weight of the insulating base.

Wiring board [0008] The present invention is characterized in that the surface was coated copper powder particle size of 0.1μm or 50μm of aluminum or nickel.

Further, the wiring board of the present invention is characterized in that the thickness of aluminum or nickel covering the surface of the copper powder of the wiring conductor is 0.1 μm to 10 μm.

Further, the method for manufacturing a wiring board according to the present invention comprises:
A step of preparing a precursor sheet serving as an insulating substrate in which a thermosetting resin precursor and an inorganic insulating powder are mixed; and a step of preparing a copper sheet having a surface coated with aluminum or nickel on the precursor sheet and a thermosetting resin. A step of printing a metal paste to be a wiring conductor mixed with a precursor in a predetermined pattern, and a step of heating and curing the precursor sheet to be semi-cured,
The semi-cured precursor sheet on which the metal paste is printed
Characterized in that it consists a step of thermally curing the thermosetting resin precursor is heated to the precursor sheet of a thermosetting resin precursor and the metal paste which, together with the laminated bets on a plurality vertically Things.

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 are mutually connected or the wiring board and the semiconductor device manufacturing automatic line. Even if a portion of the insulating base material collides violently, the insulating substrate will not be chipped, cracked or cracked.

Further, according to the wiring substrate of the present invention, the content of the inorganic insulating powder in the insulating base is set to 60% by weight to 95% by weight.
The semiconductor element mounted with the thermal expansion coefficient of the insulating base while increasing the mechanical strength of the insulating base.
Is approximated to the thermal expansion coefficient, as well as reduce the thermal stress generated due to <br/> phase differences of thermal expansion coefficients of both therebetween,
It is possible to effectively prevent the semiconductor element from being cracked or chipped due to the thermal stress.

Further, according to the wiring board of the present invention, since the surface of the copper powder forming the wiring conductor is coated with nickel or aluminum to a thickness of 0.01 μm to 10 μm, unnecessary oxidation of the copper powder is prevented, and the wiring is formed. The electric resistance of the conductor can be low.

Further, according to the method of manufacturing a wiring board of the present invention, there is provided a step of preparing a precursor sheet serving as an insulating base obtained by mixing a thermosetting resin precursor and an inorganic insulating powder; Printing a metal paste to be a wiring conductor obtained by mixing a copper powder coated with aluminum or nickel and a thermosetting resin precursor in a predetermined pattern, and heating the precursor sheet to semi-curing
And the semi-cured precursor on which the metal paste is printed
Fabricated a thermosetting resin precursor is heated to <br/> the precursor sheet of a thermosetting resin precursor and the metal paste it as well as laminated sheets on a plurality down in the step of thermal curing, Since there is no firing step, there is no deformation or dimensional variation due to uneven firing shrinkage.

[0015]

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 base 1 comprises three insulating substrates 1a,
The semiconductor device 3 is formed by laminating 1b and 1c, and has a concave portion 1d for accommodating a semiconductor element in the center of the upper surface, and the semiconductor element 3 is provided on the bottom surface of the concave portion 1d via an adhesive such as resin. Adhesively fixed.

An insulating substrate 1a constituting the insulating base 1;
1b and 1c are obtained by bonding an inorganic insulating powder such as silicon oxide, aluminum oxide, aluminum nitride, silicon carbide, barium titanate, and zeolite with a thermosetting resin such as an epoxy resin, a polyimide resin, and a polyphenylene ether resin. The three insulating substrates 1a, 1b, and 1c constituting the insulating substrate 1 are formed by bonding inorganic insulating powder with a thermosetting resin having excellent toughness. Even when an external force is applied to the insulating substrate 1, the external force does not cause chipping, cracking, cracking or the like in the insulating substrate 1.

Incidentally, three insulating substrates 1 constituting an insulating base 1 formed by bonding the inorganic insulating powder with a thermosetting resin.
a, 1b, and 1c show that when the content of the inorganic insulating powder is less than 60% by weight, the thermal expansion coefficient of the insulating base 1 is lower than that of the semiconductor element 3.
When the semiconductor element 3 emits heat during operation and the heat is applied to both the semiconductor element 3 and the insulating substrate 1, the difference is caused by the difference in the thermal expansion coefficient between the two. A large thermal stress is generated, and there is a risk that the semiconductor element 3 may be separated from the insulating base 1 or the semiconductor element 3 may be cracked or chipped due to the large thermal stress. 9
5% by weight is exceeded and inorganic insulator powder can not be completely bound with a thermosetting resin, can not be obtained mechanical strength strong predetermined insulation substrate 1a, 1b, and 1c.
Therefore, the insulating substrates 1a, 1
It is preferable that the amount of the inorganic insulating powder contained in each of b and 1c is in the range of 60 % by weight to 95% by weight.

The insulating base 1 is formed with a wiring conductor 2 attached from the periphery of the concave portion 1d to the lower surface. The wiring conductor 2 is made of a thermosetting resin made of copper powder whose surface is coated with aluminum or nickel. It is formed so as to be attached to the insulating base 1 via an interposition.

The wiring conductor 2 serves to electrically connect each electrode of the semiconductor element 3 housed therein to an external electric circuit. Are electrically connected via bonding wires 4, and a portion led out to the lower surface of the insulating base 1 is electrically connected to an external electric circuit.

The wiring conductor 2 is formed by bonding copper powder with a thermosetting resin. Since the copper powder has good electrical conductivity, the electric resistance of the wiring conductor 2 can be reduced. .

The surface of the wiring conductor 2 made of the copper powder is coated with aluminum or nickel having excellent corrosion resistance, and the surface of the copper powder is hardly oxidized by the aluminum or nickel. 2 can be made lower resistance.

When the content of the copper powder whose surface to be the wiring conductor 2 is coated with aluminum or nickel is less than 70% by weight, the electric resistance value of the wiring conductor 2 tends to be high , and the content is 95% by weight. % certain ultra El and copper powder tends to be difficult to firmly bond a thermosetting resin. Therefore, it is preferable that the content of the copper powder contained in the wiring conductor 2 be in the range of 70 % by weight to 95% by weight.

Further, the wiring conductors 2 and made the surface copper powder coated with aluminum or nickel, copper powder is agglomerated longer uniform dispersion is obtained when the average particle diameter is less than 0.1 [mu] m, also 50μm the 50μm~200μm that are typically required the width of the wiring conductor 2 and is exceeded
Tends to be difficult to print in the range of. Therefore, it is preferable that the average particle diameter of the copper powder contained in the wiring conductor 2 be in the range of 0.1 μm to 50 μm.

Further, in the case of the copper powder coated with aluminum or nickel on the surface serving as the wiring conductor 2, if the thickness of aluminum or nickel coating the surface of the copper powder is less than 0.01 μm, the surface of the copper powder is coated with aluminum or nickel. It cannot be completely covered with nickel, making it difficult to effectively prevent oxidation of copper powder.
The tend is exceeded and the electric resistance of the wiring conductor 2 becomes large. Therefore, it is preferable that the thickness of the aluminum or nickel coating the surface of the copper powder to be the wiring conductor 2 be in the range of 0.01 μm to 10 μm.

Thus, according to the wiring board of the present invention, the semiconductor element 3 is bonded and fixed to the bottom surface of the concave portion 1d of the insulating base 1 with an adhesive such as a resin, and each electrode of the semiconductor element 3 is bonded via the bonding wire 4. It is electrically connected to the wiring conductor 2, and finally, 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 is placed inside the container formed of 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 for the semiconductor element storage package will be described with reference to FIG.

First, as shown in FIG. 2A, three precursor sheets 11a, 11b and 11c are prepared.

The three precursor sheets 11a, 11b,
11c is formed by bonding an inorganic insulating powder with a thermosetting resin precursor, and for example, has a particle size of 0.1.
1μm~100μm about silicon oxide powder of bisphenol A type epoxy resins, novolac rack type epoxy resin, epoxy resin and amine curing agent such as glycidyl ester type epoxy resin, imidazole curing agent, such as an acid anhydride curing agent A hardener is added and mixed to form a paste, and thereafter, the paste is formed into a sheet and about 25 to 1
It is manufactured by heating at a temperature of 00 ° C. for 1 to 60 minutes and semi-curing.

Next, as shown in FIG. 2 (b), two of the three precursor sheets 11a, 11b, 11c have the recess 1 for accommodating the semiconductor element 3 in the two precursor sheets 11a, 11b.
The openings A and A ′ to be d are formed by two precursor sheets 11b,
11c, through holes B and B 'for routing the wiring conductor 2 are respectively formed.

The openings A and A 'and the through holes B and B'
The precursor sheets 11a, 11b, and 11c are subjected to a conventionally known punching method, and the precursor sheets 11a, 11b, and 1c are subjected to punching.
1c is formed by piercing a hole of a predetermined shape.

Next, as shown in FIG. 2C, 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 screen printing method known in the art. A predetermined pattern is printed and applied by using a filling method, and this is heat-treated at a predetermined temperature to be semi-cured.

The metal paste 12 serving as the wiring conductor 2 has, for example, a surface thickness of 0.01 μm to 10 μm.
Copper powder coated with aluminum or nickel and having a particle size of about 0.1 to 20 μm, epoxy resin such as bisphenol A type epoxy resin, novolak type epoxy resin, glycidyl ester type epoxy resin, amine type curing agent, imidazole type A paste obtained by adding and mixing a curing agent such as a curing agent and an acid anhydride-based curing agent is used.

Finally, the three semi-cured precursor sheets 11a, 11b, and 11c are vertically stacked and heated at a temperature of about 80 to 300 ° C. for about 10 seconds to 24 hours. By completely thermosetting the thermosetting resin precursor of the sheets 11a, 11b and 11c and the thermosetting resin precursor of the metal paste 12 printed and applied in a predetermined pattern on the precursor sheets 11b and 11c, FIG.
A wiring board in which a wiring conductor 2 is adhered to an insulating base 1 as shown in FIG. In this case, the precursor sheet 11a,
11b, 11c and the metal paste 12 hardly shrink during thermosetting, and therefore hardly cause deformation or dimensional variation in the obtained wiring board.

Thus, according to the method for manufacturing a wiring board of the present invention, it is possible to provide a wiring board in which the insulating base 1 has no deformation or variation in dimensions.

It should be noted that the present invention is not limited to the above-described embodiment, and various changes can be made without departing from the scope of the present invention. Although the description has been given by taking as an example the case where the wiring board is applied to a semiconductor element housing package for housing a semiconductor element, the wiring board may be applied to a wiring board used for other purposes such as a hybrid integrated circuit.

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

[0039]

According to the wiring board of the present invention, since the insulating base is formed by bonding the inorganic insulating powder with a thermosetting resin having excellent toughness, the wiring boards are mutually connected 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.

Further, according to the wiring substrate of the present invention, the content of the inorganic insulating powder in the insulating base is set to 60% by weight to 95% by weight.
The semiconductor element mounted with the thermal expansion coefficient of the insulating base while increasing the mechanical strength of the insulating base.
, And it is possible to effectively prevent the semiconductor element from being cracked or chipped due to the thermal expansion coefficient stress.

Further, according to the wiring board of the present invention, since the surface of the copper powder forming the wiring conductor is coated with nickel or aluminum to a thickness of 0.01 to 10 μm, unnecessary oxidation of the copper powder is prevented, and The electric resistance of the conductor can be low.

Further, according to the method for manufacturing a wiring board of the present invention, a step of preparing a precursor sheet serving as an insulating base obtained by mixing a thermosetting resin precursor and an inorganic insulating powder; Printing a metal paste to be a wiring conductor obtained by mixing a copper powder coated with aluminum or nickel and a thermosetting resin precursor in a predetermined pattern, and heating the precursor sheet to semi-curing
And the semi-cured precursor on which the metal paste is printed
Fabricated a thermosetting resin precursor is heated to <br/> the precursor sheet of a thermosetting resin precursor and the metal paste it as well as laminated sheets on a plurality down in the step of thermal curing, Since there is no firing step, there is no deformation or dimensional variation due to uneven firing shrinkage.

[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.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulating base 2 ... Wiring conductor 11 ... Precursor sheet 12 ... Metal paste

────────────────────────────────────────────────── ─── Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H05K 1 / 02,1 / 03,1 / 09 H05K 3 / 12,3 / 46 H01L 23 / 12,23 / 14 H01B 1/00-1/24

Claims (5)

(57) [Claims] An inorganic insulating powder is bonded by a thermosetting resin , and said inorganic insulating powder is bonded to said thermosetting resin in front of said thermosetting resin.
The precursor sheet, which is bonded by the precursor, is semi-cured and
The above-mentioned inorganic insulating powder, which is obtained by laminating several sheets and thermally curing, is
Laminate multiple insulating substrates bonded by thermosetting resin
The semi-cured precursor is provided on the insulating substrate of the insulating substrate
A wiring board with the body sheet was thermally cured, the surface is characterized in that the copper powder coated with aluminum or nickel made by depositing a wiring conductor formed by combining a thermosetting resin. 2. A wiring board according to claim 1 wherein the amount of said inorganic insulator powder contained in the insulating substrate is the a total weight 60% to 95% by weight relative to the insulating substrate . 3. The wiring substrate according to claim 1, wherein said copper powder having a surface coated with aluminum or nickel has a particle size of 0.1 μm to 50 μm. 4. The wiring board according to claim 1, wherein the thickness of aluminum or nickel covering the surface of the copper powder is 0.01 μm to 10 μm. 5. A step of preparing a precursor sheet serving as an insulating substrate in which a thermosetting resin precursor and an inorganic insulator powder are mixed, and a copper powder whose surface is coated with aluminum or nickel on the precursor sheet. Printing a metal paste to be a wiring conductor mixed with a thermosetting resin precursor in a predetermined pattern, and heating the precursor sheet to be semi-cured.
And before the semi-curing on which the metal paste is printed
The precursor sheets are stacked one above the other and
Heating said precursor thermosetting resin precursor and the previous sheet
Method for manufacturing a wiring substrate, characterized by comprising a thermosetting resin precursor serial metal paste from the step of heat curing.