JP3393768B2 - 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,
More specifically, the present invention relates to a semiconductor element housing package for housing a semiconductor element, a wiring board used in a hybrid integrated circuit device, and the like.

[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 the semiconductor element is housed in the center of its upper surface. 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 of the insulating base to the lower surface, and a semiconductor element is formed on the bottom of the recess of the insulating base. The electrodes are bonded and fixed via an adhesive such as glass, resin, or a brazing material, and each electrode of the semiconductor element is electrically connected to a wiring conductor through an electrical connecting means such as a bonding wire. A sealing member made of glass, resin, brazing material, etc. is formed on the upper surface of the insulating base by covering the concave portion of the insulating base with a lid made of metal or ceramics. Through by joining a semiconductor device as a product by housing airtightly semiconductor element in the recess of the insulating substrate.

This conventional wiring board is generally manufactured by a ceramic green sheet laminating method,
Specifically, aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, and other ceramic raw material powders are mixed with an appropriate organic binder, solvent, etc. to form a slurry, and this is adopted by the conventionally known doctor blade method.
A plurality of ceramic green sheets are obtained by forming a sheet, and thereafter, the ceramic green sheets are appropriately punched and a metal paste to be a wiring conductor is printed and applied in a predetermined pattern, and finally the ceramic green sheets are formed. Are laminated in a predetermined order to form a green ceramic compact, and the green ceramic compact is fired in a reducing atmosphere at a high temperature of about 1600 ° C.

However, in this conventional wiring board, since the ceramics such as the aluminum oxide sintered body forming the insulating substrate has a hard and brittle property, the wiring boards may not be connected to each other in a carrying process or an automatic line for manufacturing a semiconductor device. Or, if the wiring board and a part of the automatic production line for semiconductor devices collide violently, the insulating substrate may be chipped, cracked, or cracked. As a result, the semiconductor element cannot be hermetically housed and the semiconductor element is long. It has a drawback that it cannot operate normally and stably over a period of time.

According to the method of manufacturing the wiring board,
When firing the green ceramic compact, uneven firing shrinkage occurs in the raw ceramic compact, resulting in deformation such as warpage and dimensional variation in the obtained wiring board, and each electrode of the semiconductor element is used as a predetermined wiring conductor. Alternatively, there is a drawback that the wiring conductor cannot be electrically connected to a predetermined external electric circuit accurately and surely.

Therefore, the insulating substrate of the wiring board is replaced with the conventional ceramics and the inorganic insulating powder is bonded with the thermosetting resin, and the wiring conductor is replaced with the conventional refractory metal powder, and the metal powder is thermoset. A wiring board made of resin is proposed. A wiring board composed of an insulating substrate formed by bonding the inorganic insulating powder with a thermosetting resin and a wiring conductor formed by bonding a metal powder with the thermosetting resin is composed of the thermosetting resin and the inorganic insulating powder. A semi-cured precursor sheet prepared by mixing is prepared, and the precursor sheet is subjected to an appropriate punching process, and then a metal paste formed by mixing a thermosetting resin and metal powder is formed into a predetermined pattern. If necessary, a precursor sheet on which the above-mentioned metal paste is printed and applied is laminated by printing and applied, and this is applied to about 100
It is manufactured by heat curing at a temperature of ~ 300 ° C.

[0007]

However, a wiring board comprising an insulating substrate formed by bonding the inorganic insulating powder with a thermosetting resin and a wiring conductor formed by bonding a metal powder with the thermosetting resin is The bonding strength of the wiring conductor to the insulating base is slightly weak, and when a large external force is applied to the wiring conductor when connecting the electrodes of the semiconductor element to the wiring conductor, the wiring conductor is separated from the insulating base by the external force, and the semiconductor element, etc. There was a problem to be solved that the reliability of the electrical connection between the electrode and the wiring conductor was slightly inferior.

The present invention has been devised in view of the above-mentioned drawbacks, and an object thereof is to strengthen the connection between the insulating substrate and the wiring conductor and to firmly electrically connect the electrode of the semiconductor element and the like to the wiring conductor. To provide a wiring board.

[0009]

A wiring board according to the present invention comprises 6
0 Ri and a wt% to 95 wt% of the inorganic insulator powder and 5 wt% to 40 wt% of a thermosetting resin formed, precursor sheet comprising the inorganic insulator powder bonded by the thermosetting resin
Semi-cured, the inorganic insulating powder is heat-cured.
A semi-cured precursor sheet on the insulating substrate of an insulating substrate formed by laminating a plurality of insulating substrates bonded together by a conductive resin.
Both thermally cured, the metal powder to a wiring substrate formed by depositing the wiring conductor joined by a thermosetting resin, is wearing the between and wiring conductors and said insulating base plate and the wiring conductor
Of the insulating substrate and the insulating substrate laminated on the insulating substrate
In between , a silane coupling agent is added to the thermosetting resin in an amount of 2 to 10
It is characterized in that an intermediate layer formed by including parts by weight is interposed.

[0010] method of manufacturing a wiring board of the present invention, Ru formed by mixing a thermosetting resin precursor and the inorganic insulating powder, hard
Of preparing a precursor sheet to be an insulating substrate after conversion ,
Semi-curing the precursor sheet; applying a resin paste obtained by adding a silane coupling agent to a thermosetting resin precursor to one surface of the semi-cured precursor sheet; a step of applying Ru on the resin paste by mixing a metal powder thermosetting resin precursor formed that is, a metal paste comprising a wiring conductor after curing a predetermined pattern, wherein the precursor sheet, resin paste and the metal paste Heat treatment,
It is characterized by comprising a heat curing step.

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 between the wiring boards and the semiconductor device manufacturing line. Even if a part of the insulating base material violently collides with the insulating base material, the insulating base material will not be chipped, cracked, or cracked.

[0012] According to the wiring board of the present invention, an insulating substrate on which is deposited between and wiring conductors of the wiring conductor and the insulating board <br/>
An intermediate layer comprising a thermosetting resin having good adhesiveness between the insulating layer and the insulating substrate laminated thereon and a silane coupling agent such as γ-glycidoxypropyltrimethoxysilane in an amount of 2 to 10 parts by weight. bonding strength of the wiring conductor for insulating board <br/> since that is interposed becomes extremely strong by said intermediate layer, as a result, a large external force to the wiring conductor in such when connecting electrodes of the semiconductor element to the wiring conductor There never even wiring conductor is applied is peeled from the insulating base plate, ensuring an electrode of a semiconductor element or the like on the wiring conductors, it is possible to firmly electrically connected.

Further , according to the method for manufacturing a wiring board of the present invention,
For example , mix the thermosetting resin precursor with the inorganic insulating powder.
Ru formed, a step of preparing a precursor sheet comprising an insulating substrate after the curing, a step of semi-curing the precursor sheet, semi hard
A step of applying a resin paste obtained by adding a silane coupling agent to a thermosetting resin precursor on one surface of the precursor sheet that has been made into a mixture, and mixing the thermosetting resin precursor and metal powder on the applied resin paste forming Ru and a wiring conductor after curing
The precursor sheet, the resin paste, and the thermosetting resin of the metal paste are manufactured by a step of applying the metal paste in a predetermined pattern and a step of heat-treating the precursor sheet, the resin paste and the metal paste, and thermosetting the precursor sheet, the resin paste and the metal paste. Since the precursor hardly shrinks during thermosetting, deformation or dimensional variation due to uneven shrinkage does not occur.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the accompanying drawings. 1 and 2 show an embodiment of the application of the wiring board to the semiconductor device housing package for housing a semiconductor device of the present invention, 1 denotes an insulating substrate, 2 denotes a wiring conductor.

The insulating substrate 1 is composed of three insulating substrates 1a and 1a.
It is formed by laminating b and 1c, and has a concave portion 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 concave portion 1d via an adhesive such as resin. Adhesively fixed.

The three insulating substrates 1a, 1b and 1c constituting the insulating base 1 are, for example, silicon oxide, aluminum oxide, aluminum nitride, silicon carbide, barium titanate,
It is formed by bonding inorganic insulating powder such as zeolite with a thermosetting resin such as epoxy resin or polyimide resin, and three insulating substrates 1 constituting the insulating substrate 1 are formed.
Since each of a, 1b, and 1c is formed by joining inorganic insulating powders 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 to the insulating base 1 by the external force. No chipping, cracking, or cracking occurs.

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, and the large thermal stress causes the semiconductor element 3 to be separated from the insulating substrate 1, or the semiconductor element 3 to be 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% by weight to 95% by weight.

A wiring conductor 2 is formed from the periphery of the concave portion 1d to the lower surface of the insulating base 1 by binding a metal powder such as copper, silver or gold with a thermosetting resin such as an epoxy resin.

The wiring conductor 2 serves to electrically connect the semiconductor element 3 housed therein to an external electric circuit,
The electrodes of the semiconductor element 3 are electrically connected to the peripheral portion of the recess 1d through the bonding wires 4, and the portion leading to the lower surface of the insulating substrate 1 is electrically connected to the external electric circuit board.

When the amount of the metal powder contained in the wiring conductor 2 is less than 70% by weight, the conductivity of the wiring conductor 2 tends to deteriorate, and when it exceeds 95% by weight, the metal powder is made of a thermosetting resin. A strong bond tends to be difficult. Therefore, the wiring conductor 2 formed by binding the metal powder with a thermosetting resin has a metal powder content of 70 to 9 wt%.
It is preferable to set it in the range of 5% by weight.

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

The wiring conductor 2 has a bump electrode 2a electrically connected to an external electric circuit formed on the lower surface of the insulating substrate 1. The bump electrode 2a is connected to the wiring of the external electric circuit board. By joining the conductor to the conductor via a conductive adhesive such as solder, the semiconductor element 3 housed inside is electrically connected to an external electric circuit.

Further, as shown in FIG. 2, an intermediate layer 5 is interposed between the wiring conductor 2 and the upper surface of the insulating substrate 1b constituting the insulating substrate 1, and the intermediate layer 5 allows the wiring conductor 2 to be formed.
The adhesion between the insulating substrate 1b and
Even when a large external force is applied to the wiring conductor 2 when the electrodes of the semiconductor element 3 are connected to the wiring conductor 2 via the bonding wire 4, the wiring conductor 2 is separated from the insulating base 1 (the upper surface of the insulating substrate 1b) by the external force. By so doing, each electrode of the semiconductor element 3 can be securely connected to the wiring conductor 2,
A strong electrical connection can be achieved.

The intermediate layer 5 comprises a thermosetting resin such as an epoxy resin or a polyimide resin containing 2 to 10 parts by weight of a silane coupling agent, and the functional group of the silane coupling agent is the surface of the insulating substrate 1b. Hydrogen bonding with the inorganic insulating powder and the metal powder of the wiring conductor 2 exposed at the same time, and at the same time, the lipophilic group is bonded with the thermosetting resin of the intermediate layer 5 to make the wiring conductor 2 extremely strong on the upper surface of the insulating substrate 1b. Join.

As the silane coupling agent contained in the intermediate layer 5, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane,
There are β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane and the like, but especially γglycidoxypropyltrimethoxysilane. Is preferable because it has good compatibility with the thermosetting resin of the intermediate layer 5 and the film surface is smooth.

When the content of the silane coupling agent contained in the intermediate layer 5 is less than 2 parts by weight, the wiring conductor 2 cannot be firmly bonded onto the insulating substrate 1b, and 10 parts by weight. If it exceeds, the film strength of the intermediate layer 5 will be reduced. Therefore, the content of the silane coupling agent contained in the intermediate layer 5 is specified in the range of 2 to 10 parts by weight.

Further, when the thickness of the intermediate layer 5 is less than 3 μm, it becomes difficult to firmly bond the wiring conductor 2 onto the insulating substrate 1b, and when it exceeds 20 μm, the thermosetting resin contains an inorganic insulating powder. When heat is applied to the insulating substrate 1b thus formed and the intermediate layer 5 made of a thermosetting resin containing a silane coupling agent, a peeling occurs between the two. There is a risk that it will occur. Therefore, the intermediate layer 5 has a thickness of 3 μm to 20 μm.
It is preferable to set it in the range of μm.

Thus , according to the above-mentioned wiring board , the semiconductor element 3 is adhered and fixed to the bottom surface of the recess 1d of the insulating substrate 1 with an adhesive, and each electrode of the semiconductor element 3 is connected to the wiring conductor 2 with the bonding wire 4. After electrically connecting, the lid body 6 is bonded to the upper surface of the insulating base body 1 through a sealing material, and the semiconductor element 3 is hermetically housed in the container including the insulating base body 1 and the lid body 6. As a result, it becomes a semiconductor device as a product.

Next, a method of manufacturing the wiring board used for the semiconductor element housing package will be described with reference to FIG. First, as shown in FIG. 3A, three precursor sheets 11a, 11b and 11c are prepared.

The three precursor sheets 11a, 11b,
11c is an inorganic insulating powder such as silicon oxide, aluminum oxide, aluminum nitride, silicon carbide, barium titanate, strontium titanate, or titanium oxide, which is an epoxy resin,
It is formed by bonding with a thermosetting resin precursor such as a polyimide resin or a polyphenylene ether resin. For example, a silicon oxide powder having a particle size of 0.1 to 100 μm is added to a bisphenol A type epoxy resin, a novolac type epoxy resin, Epoxy resin such as glycidyl ester type epoxy resin, and amine type curing agent, imidazole type curing agent, curing agent such as acid anhydride type curing agent are added and mixed to form a paste, and then this paste is formed into a sheet. It is manufactured by heating at a temperature of about 25 to 100 ° C. for 1 to 60 minutes and half-curing.

Next, as shown in FIG. 3B, a resin paste film 15 is formed on the upper surface of the precursor sheet 11b.

The resin paste film 15 is an epoxy resin,
A thermosetting resin precursor such as a polyimide resin or a polyphenylene ether resin is mixed with a silane coupling agent such as γ-glycidoxypropyltrimethoxysilane in an amount of 2 to 10 parts by weight to prepare a resin paste, which is used as the precursor sheet 11b. To a thickness of 3 μm to 20 μm on the upper surface of the precursor sheet 11b to form it on the upper surface of the precursor sheet 11b.

Precursor sheet 1 of the resin paste film 15
To form 1b on the upper surface, a precursor sheet 11b is once formed, and then a resin paste containing a silane coupling agent in a thermosetting resin precursor is applied to the upper surface of the precursor sheet 11b, and Heat treatment is performed to semi-cure the thermosetting resin in the resin paste, or a paste obtained by mixing the inorganic insulating powder and the thermosetting resin precursor is formed into a sheet, and the thermosetting resin is applied to the upper surface of the sheet. A resin paste containing a silane coupling agent is applied to the resin precursor to a predetermined thickness, and then these are applied to about 2
Heat-treated for 1 to 60 minutes at a temperature of 5 to 100 ° C., is carried out by each semi-curing the thermosetting resin of the thermosetting sheet resin and the resin paste.

Next, as shown in FIG. 3 (c), two precursor sheets 11a, 11b, 11c among the three precursor sheets 11a, 11b, 11c have openings for forming recesses 1d for accommodating the semiconductor element 3 therein. A and A ′ are two precursor sheets 11
a through hole B for routing the wiring conductor 2 to b and 11c,
Form each B '.

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 precursor sheets 11a, 11b, 11 '.
It is formed by drilling a hole of a predetermined shape in each of c.

Next, as shown in FIG. 3 (d), 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. While printing and applying in a predetermined pattern, this is heated at a temperature of about 25 to 100 ° C. for 1 to 60 minutes,
Semi-cure.

As the metal paste 12, for example,
Epoxy resin such as bisphenol A type epoxy resin, novolac type epoxy resin, glycidyl ester type epoxy resin, etc. in powder of copper or the like having a particle size of about 0.1 to 20 μm, and amine type curing agent, imidazole type curing agent, acid anhydride A paste in which a curing agent such as a system curing agent is added and mixed is used.

Finally, the three precursor sheets 11
a, 11b and 11c are laminated on top of each other and heated at a temperature of about 80 to 300 ° C. for 10 seconds to 24 hours, and printed and applied to the precursor sheets 11a, 11b and 11c, the resin paste film 15 and a predetermined pattern. Metal paste 1
By completely thermosetting 2, the wiring substrate in which the wiring conductor 2 is attached to the insulating substrate 1 as shown in FIG. 1 is completed. In this case, the precursor sheets 11a, 11b, 11
c, the resin paste film 15 and the metal paste 12 hardly shrink during thermosetting, and therefore, the obtained wiring board is not deformed or the dimensions are not uniform, which allows the semiconductor element and the wiring conductor to be accurately arranged. It is possible to connect to.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in the above-mentioned embodiments, the wiring of the present invention is used. The case where the substrate is applied to a semiconductor element housing package that houses a semiconductor element has been described as an example.
This can of course be also applied as a wiring substrate used in the mixed forming an integrated circuit.

In the above-mentioned embodiment, the wiring board is manufactured by stacking three precursor sheets, but it may be formed by stacking one, two, or four or more insulating boards. Good.

[0041]

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 line violently collides, the insulating substrate will not be chipped, cracked, or cracked.

[0042] According to the wiring board of the present invention, the absolute of depositing and between the wiring conductors of the wiring conductor and the insulating board <br/>
Between the edge substrate and the insulating substrate laminated on the edge substrate, a thermosetting resin having good adhesion to both is added with 2 to 10 parts by weight of a silane coupling agent such as γ-glycidoxypropyltrimethoxysilane. comprising the bonding strength of the wiring conductor for insulating base plate since the intermediate layer is interposed becomes extremely strong by said intermediate layer, as a result, a large external force to the wiring conductor in such when connecting electrodes of the semiconductor element to the wiring conductor It is applied not the wiring conductor is peeled off from the insulating base plate, ensuring an electrode of a semiconductor element or the like on the wiring conductors, it is possible to firmly electrically connected.

Further , according to the method for manufacturing a wiring board of the present invention,
For example , mix the thermosetting resin precursor with the inorganic insulating powder.
Ru formed, a step of preparing a precursor sheet comprising an insulating substrate after the curing, a step of semi-curing the precursor sheet, semi hard
A step of applying a resin paste obtained by adding a silane coupling agent to a thermosetting resin precursor on one surface of the precursor sheet that has been made into a mixture, and mixing the thermosetting resin precursor and metal powder on the applied resin paste forming Ru and a wiring conductor after curing
The precursor sheet, the resin paste, and the metal paste are heat-cured, and the precursor sheet, the resin paste, and the metal paste are heat-cured. Since the precursor hardly shrinks during thermosetting, deformation or dimensional variation due to uneven shrinkage does not occur.

[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.

FIG. 2 is an enlarged cross-sectional view of a main part of the wiring board shown in FIG.

3 (a) to 3 (d) are cross-sectional views for each step for explaining the method for manufacturing a wiring board of the present invention.

[Explanation of symbols]

1 ... Insulating substrate 1a, 1b, 1c ... Insulating substrate 2 ... Wiring conductor 5: Middle layer 11a, 11b, 11c ... Precursor sheet 12: Metal paste 15: Resin paste film

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H05K 3/46 H05K 3/46 T H01L 23/14 R 23/12 N (58) Fields investigated (Int.Cl. ⁷ , DB Name) H05K 1/02 H05K 1/03 H05K 1/09 H05K 3/12 H05K 3/46 H01L 23/12-23/15 H01B 1/00-1/24

Claims (4)

(57) [Claims] 1. 60% by weight to 95% by weight of inorganic insulating powder
From powder and 5% to 40% by weight of thermosetting resinSuccess
Bond the inorganic insulating powder with the thermosetting resin.
ShiThe semi-cured precursor sheet consisting of
A plurality of powders bonded by the thermosetting resinInsulation board
StackingInsulating base consistingOf the insulating substrateToBefore semi-curing
Heat cured together with the precursor sheet,Thermosetting metal powder
Wiring formed by depositing wiring conductors bonded with a chemical resin
A substrate, the insulating substrateBoardBetween the wiring conductor andAnd the
The insulating substrate on which the wiring conductor is adhered and laminated on the insulating substrate
Between the insulating substrateThermosetting resin with silane coupling
And an intermediate layer containing 2 to 10 parts by weight of a coating agent is interposed.
A wiring board characterized by being made. 2. The wiring board according to claim 1, wherein the intermediate layer has a thickness of 3 μm to 20 μm. 3. The wiring board according to claim 1, wherein the silane coupling agent is γ-glycidoxypropyltrimethoxysilane. 4. Ru formed by mixing a thermosetting resin precursor and the inorganic insulator powder, a step of preparing a precursor sheet comprising an insulating substrate after curing, step of semi-curing the precursor sheet
And a step of applying a resin paste obtained by adding a silane coupling agent to a thermosetting resin precursor on one surface of the semi-cured precursor sheet, and a thermosetting resin precursor and a metal on the applied resin paste. formed Ru by mixing a powder, after curing
And a step of applying a metal paste to be a wiring conductor in a predetermined pattern, and a step of heat-treating the precursor sheet, the resin paste and the metal paste to heat-cure them.
And a method for manufacturing a wiring board.