JP3301909B2 - 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 the semiconductor element is housed in the center of the 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 to the lower surface of the concave portion of the insulating substrate, and a semiconductor element is formed on the bottom surface of the concave portion of the insulating substrate. Glass, resin, adhesively fixed via an adhesive such as a brazing material, and electrically connecting each electrode of the semiconductor element to a wiring conductor through an electrical connection means such as a bonding wire, and thereafter,
On the upper surface of the insulating substrate, a cover made of a metal, ceramics, or the like, so as to cover a concave portion of the insulating substrate, glass, resin,
A semiconductor device as a product is obtained by joining the semiconductor element in a concave portion of the insulating base in an airtight manner by joining through a sealing material such as a brazing material. The semiconductor element to be accommodated is electrically connected to the external electric circuit board by connecting to the wiring conductor of the board via an electrical connection means such as solder.

Incidentally, this conventional wiring board is generally manufactured by a ceramic green sheet laminating method, and specifically, an organic binder suitable for a ceramic raw material powder such as aluminum oxide, silicon oxide, magnesium oxide and calcium oxide. , A solvent and the like are added and mixed to form a slurry, and this is formed into a sheet by employing a conventionally known doctor blade method to obtain a plurality of ceramic green sheets. After processing, 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 firing at a high temperature of 1600 ° C.

[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 green ceramic molded body, unevenness in firing shrinkage occurs in the green ceramic molded body due to variations in the density of the ceramic raw material powder in each ceramic green sheet, and the resulting wiring board has deformation and dimensions such as warpage. As a result, it is difficult to electrically and accurately connect the semiconductor element and the wiring conductor, and if the deformation or the dimensional variation is large, the wiring conductor will be disconnected. Had disadvantages.

[0006]

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
Consisting of a thermosetting resin, wherein the inorganic insulating powder is
Precursor sheet composed of thermosetting resin precursor
Thereof a plurality are stacked and thermally cured by curing, plural linked by the thermosetting resin the inorganic insulator powder
The insulating substrate of the insulating substrate formed by laminating the insulating substrates of
It is characterized in that at least two types of single element metal powder made by depositing the wiring conductor made of a metal member and a thermosetting resin which is formed are joined to each other by alloying.

Further, according to the method of manufacturing a wiring board of the present invention, there is provided a step of preparing a precursor sheet formed by mixing a thermosetting resin precursor and an inorganic insulating powder, and heating the precursor sheet.
Semi-curing by heating, and printing a metal paste obtained by mixing a thermosetting resin precursor and at least two types of single-element metal powders in a predetermined pattern on the semi-cured precursor sheet, and heating and heating the metal paste. Curing process and semi-curing
Semi-cured precursor on which the metal paste is applied
This heat treatment, the precursor sheet and said metal with at least two types of single element metal powder of the metal paste to form a metal member is joined to each other by alloying with stacking a sheet on a plurality vertically A step of thermosetting and integrating the thermosetting resin precursor of the paste.

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 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 board of the present invention, when heat-treating the metal paste to form a wiring conductor, the metal member of the wiring conductor is joined to each other by alloying at least two kinds of single element metal powders. As a result, the electrical connection between the metal powders is ensured, and as a result, the electrical resistance of the wiring conductor can be reduced.

Further, according to the method for manufacturing a wiring board of the present invention,
In the wiring board includes the steps of preparing a precursor sheet formed by mixing a thermosetting resin precursor and the inorganic insulating powder, front
Heating the precursor sheet to semi-curing; and applying the semi-cured precursor sheet to a metal paste obtained by mixing a thermosetting resin precursor and at least two types of single element metal powders. Print in a predetermined pattern and heat it to make it semi-cured
And that step, half of the semi-cured the metal paste is deposited
A plurality of the precursor sheets for curing are laminated one above the other.
This was heated to the precursor sheet and the front with at least two types of single element metal powder of the metal paste to form a metal member is joined to each other by alloying
The thermosetting resin precursor of the metal paste is thermoset and integrated, and the precursor sheet and the thermosetting resin precursor of the metal paste hardly shrink during thermosetting. There is no deformation or dimensional variation.

The alloying of at least two types of single-element metal powders contained in the metal paste is performed at the contact portions of the respective single-element metal powders, and the contact is extremely narrow. The alloying can be performed at a low temperature without requiring a high temperature. As a result, when the precursor sheet on which the metal paste is printed in a predetermined pattern is heat-treated to form a wiring board, the thermosetting properties of the precursor sheet and the metal paste are reduced. At least two kinds of single element metal powders can be reliably joined to each other by alloying without causing thermal decomposition of the resin.

[0012]

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 package for housing a semiconductor element for housing a semiconductor element, wherein 1 is an insulating base, and 2 is a wiring conductor.

The insulating substrate 1 comprises three insulating substrates 1a, 1
The semiconductor element 3 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. Adhesively fixed.

The three insulating substrates 1a, 1b and 1c constituting the insulating base 1 are made of, for example, silicon oxide, aluminum oxide, aluminum nitride, silicon carbide, barium titanate,
Inorganic insulator powder epoxy resin such as zeolite, is formed by bonding a thermosetting resin such as polyimide resin, three sheets constituting the insulating substrate 1 insulating substrate 1
a, 1b, and 1c are each formed by bonding inorganic insulating powder with a thermosetting resin having excellent toughness. Therefore, 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 chips, cracks, cracks, etc., occur.

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 each have a content of the inorganic insulating powder of 60% by weight.
If it is less than 1, the coefficient of thermal expansion of the insulating substrate 1 greatly differs from the coefficient of thermal expansion of the semiconductor element 3, and the semiconductor element 3 generates heat during operation, and the heat is applied to both the semiconductor element 3 and the insulating substrate 1. A large thermal stress is generated between the semiconductor element 3 and the semiconductor element 3 due to a difference in thermal expansion coefficient between the semiconductor element 3 and the large thermal stress, and the semiconductor element 3 is separated from the insulating base 1 or the semiconductor element 3 is cracked or chipped. . 95% by weight
Ultra El and the inorganic insulating powder can not be completely bound with a thermosetting resin, it becomes impossible to obtain a predetermined insulating substrate 1a, 1b, and 1c. Accordingly, the amount of the inorganic insulating powder contained in each of the insulating substrates 1a, 1b, and 1c constituting the insulating base 1 is specified in the range of 60% by weight to 95% by weight.

The insulating substrate 1 is provided with a wiring conductor 2 attached from the periphery of the concave portion 1d to the lower surface. The wiring conductor 2 is formed by joining at least two kinds of single element metal powders by alloying. It is made of a metal member to be formed and a thermosetting resin such as an epoxy resin or a polyimide resin. The metal member is attached to the insulating substrate 1 with the thermosetting resin to be integrally covered with the insulating substrate 1. Is being worn.

The at least two kinds of single element metal powder forming the wiring conductor 2 include gold, germanium, magnesium, manganese, praseodymium, antimony, silver,
At least one kind of aluminum and copper, lead, tin, at least one kind of gold and bismuth, silver, at least one kind of lead and lithium, or tin, at least one kind of antimony and gold,
Combinations of magnesium and zinc, lead and tin, and the like are preferably used.

The wiring conductor 2 functions to electrically connect the semiconductor element 3 housed therein to an external electric circuit.
Each electrode of the semiconductor element 3 is electrically connected to a portion around the concave portion 1d through a bonding wire 4, and a portion extending to the lower surface of the insulating base 1 is electrically connected to an external electric circuit board.

Since the wiring conductor 2 is formed by joining at least two kinds of single element metal powders to each other by alloying, at least two metal members are formed.
The electrical connection between the types of single element metal powder is ensured, and the electrical resistance of the wiring conductor 2 can be reduced.

Thus, according to the above-mentioned wiring board, the semiconductor element 3 is bonded and fixed to the bottom surface of the concave portion 1d of the insulating base 1, and each electrode of the semiconductor element 3 is electrically connected to the wiring conductor 2 via the bonding wire 4. Finally, a lid 5 is bonded to the upper surface of the insulating base 1 via a sealing material, and the semiconductor element 3 is hermetically accommodated in a container including the insulating base 1 and the lid 5 to thereby provide a semiconductor product. Device.

Next, a method of manufacturing a wiring board used in the package for housing a semiconductor element 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 an epoxy resin made of an inorganic insulating powder such as silicon oxide, aluminum oxide, aluminum nitride, silicon carbide, barium titanate, strontium titanate, and titanium oxide;
Polyimide resin is formed by bonding a thermosetting resin precursor such as polyphenylene ether resin, for example particle size in the silicon oxide powder of 0.1 to 100 [mu] m, Bisufe Roh Lumpur A type epoxy resin, novolak type An epoxy resin such as an epoxy resin and a glycidyl ester type epoxy resin and a curing agent such as an amine-based curing agent, an imidazole-based curing agent, and an acid anhydride-based curing agent are added and mixed to form a paste, and then the 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 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 ′ serving as 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, A 'and the through holes B, B' are formed by subjecting the precursor sheets 11a, 11b, 11c to a conventionally well-known punching method to form the precursor sheets 11a, 11b, 11b.
c is formed by piercing a hole of a predetermined shape in each of c.

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 conventionally known screen printing method. Print and apply in a predetermined pattern and heat it at a temperature of about 25-100 ° C for 1-60 minutes,
Semi-cured.

The metal paste 12 includes at least two kinds of single element metal powders, an epoxy resin such as a bisphenol A type epoxy resin, a novolak type epoxy resin, a glycidyl ester type epoxy resin, an amine type curing agent and an imidazole type curing agent. A paste obtained by adding and mixing a curing agent such as an acid anhydride-based curing agent is used.

Finally, the three precursor sheets 11
a, 11b, and 11c are vertically stacked and heated at a temperature of about 300 ° C. for 10 seconds to 24 hours, and at least two kinds of single element metal powders in the metal paste 12 are joined to each other by alloying. Precursor sheets 11a, 11b, 11c and metal paste 1 as well as metal members
By completely thermosetting and integrating the two thermosetting resin precursors, a wiring substrate used for a semiconductor element storage package in which a wiring conductor 2 is adhered to an insulating base 1 as shown in FIG. 1 is completed. I do. In this case, the precursor sheet 1
The wires 1a, 11b, and 11c hardly shrink during thermosetting, so that the resulting wiring board is effectively prevented from being deformed or having a variation in dimension, and the wiring conductor 2 is not broken. Electrodes such as the semiconductor element 3 can be reliably electrically connected to an external electric circuit via the conductor 2. At the same time, since the metal member of the wiring conductor 2 is formed by joining at least two types of single element metal powders to each other by alloying, the bonding between the single element metal powders becomes reliable and strong. The electric resistance of the conductor 2 can be made low.

Further, at least two kinds of single-element metal powders in the metal paste 12 are alloyed at the contact portions of the respective single-element metal powders, and since the contact is extremely narrow, the alloying is performed at a high temperature. Can be carried out at a low temperature without the necessity, and as a result, the precursor sheets 11a, 11b, 11c on which the metal paste 12 is printed in a predetermined pattern
Heat treatment to form a wiring board, the precursor sheet 11a,
At least two types of single element metal powders can be reliably joined to each other by alloying without causing thermal decomposition of the thermosetting resin of the metal pastes 11b and 11c.

The metal paste 12 composed of at least two kinds of single-element metal powders and a thermosetting resin has a weight of at least two kinds of single-element metal powders.
Mutual bonding by alloying between the total weight with respect to the less than 70 wt% of at least two types of single element metal powder tend to be incomplete, also formed 95% by weight is exceeded and a thermosetting resin It is difficult to firmly adhere the wiring conductor 2 to the insulating base 1 and the wiring conductor 2 tends to be weak. Therefore, the weight of at least two kinds of single element metal powder contained in the metal paste 12 is 70% by weight to 95% by weight based on the total weight of the metal paste 12.
It is preferable to set the range.

Further, at least two kinds of single element metal powder contained in the metal paste 12 have a particle diameter of 0.1.
single elemental metal powder is less than μm becomes higher electrical resistance of the wiring conductor 2 that aggregated uniformly dispersed is formed not be obtained, also 50μm ultra Ell and the metal paste 12
Cannot be printed finely, and the wiring conductor 2 formed
It is difficult to make the width of 50 μm to 200 μm generally required. Therefore, the metal paste 1
It is preferable that at least two kinds of single element metal powders contained in No. 2 have a particle diameter in a range of 0.1 μm to 50 μm.

If at least two kinds of single element metal powders contained in the metal paste 12 are made equal in amount of each single element metal powder, the respective single element metal powders can be reliably joined to each other by alloying. It becomes possible. Therefore, it is preferable that at least two types of single element metal powders contained in the metal paste 12 have the same amount of each single element metal powder.

Further, the present invention is not limited to the above-described embodiment, but may be made within the scope of the present invention.
Various modifications are possible. For example, in the above-described embodiment, the case where the wiring board of the present invention is applied to a semiconductor element housing package for housing a semiconductor element has been described as an example, but this is applied to a hybrid integrated circuit board or the like. The present invention may be applied to a used wiring board.

Further, in the above embodiment, the wiring substrate is formed by laminating three insulating substrates. However, the wiring substrate is formed by laminating one, two, or four or more insulating substrates. Is also good.

Further, in the above-described embodiment, a thermosetting resin such as an epoxy resin used for the metal paste 12 contains a conductive resin such as a polyacetylene resin or a polyphenylene resin, or a conductive polypyrrole. When a thermosetting and conductive resin such as a resin, polyparaphenylene resin, or polyaniline resin is used as an alternative,
When the precursor sheet 11a, 11b, 11c on which the metal paste 12 is printed in a predetermined pattern is subjected to heat treatment to form a wiring board, at least two types of single element metal powder are partially incompletely interconnected by alloying. If any, the imperfect part is supplemented by an electrical connection made of a conductive resin. As a result, the electrical connection between the single element metal powders becomes more reliable, and the electrical resistance of the wiring conductor 2 becomes lower. Can be made.

[0037]

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.

According to the wiring board of the present invention, when heat-treating the metal paste to form a wiring conductor, the metal member of the wiring conductor is formed by joining at least two kinds of single element metal powders to each other by alloying. As a result, the electrical connection between the metal powders is ensured, and as a result, the electrical resistance of the wiring conductor can be reduced.

Further, according to the method for manufacturing a wiring board of the present invention,
In the wiring board includes the steps of preparing a precursor sheet formed by mixing a thermosetting resin precursor and the inorganic insulating powder, front
Heating the precursor sheet to semi-curing; and applying the semi-cured precursor sheet to a metal paste obtained by mixing a thermosetting resin precursor and at least two types of single element metal powders. Print in a predetermined pattern and heat it to make it semi-cured
And that step, half of the semi-cured the metal paste is deposited
A plurality of the precursor sheets for curing are laminated one above the other.
This was heated to the precursor sheet and the front with at least two types of single element metal powder of the metal paste to form a metal member is joined to each other by alloying
The thermosetting resin precursor of the metal paste is thermoset and integrated, and the precursor sheet and the thermosetting resin precursor of the metal paste hardly shrink during thermosetting. There is no deformation or dimensional variation.

[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.

FIGS. 2A to 2C are cross-sectional views illustrating a method of manufacturing a wiring board according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulating base 1a, 1b, 1c ... Insulating substrate 2 ... Wiring conductor 11a, 11b, 11c ... Precursor Body sheet 12 Metal paste

Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H05K 1 / 02,1 / 03,1 / 09 H05K 3 / 12,3 / 46 H01L 23/12-23/15 H01B 1 / 00-1/24

Claims (2)

(57) [Claims] An inorganic insulating powder of 60 to 95% by weight and 5
Or consists of a 40 wt% of a thermosetting resin, wherein the inorganic insulation
Before bonding the edge powder with the thermosetting resin precursor
Semi-cured precursor sheets, laminating multiple sheets and heat curing
In front of an insulating substrate formed by laminating a plurality of insulating substrates obtained by bonding the inorganic insulating powder with the thermosetting resin.
The serial insulating substrate, especially that made by depositing the wiring conductor composed of at least two metal members single elemental metal powder is formed are joined to each other by alloying of the thermosetting resin
Wiring board to be featured. 2. A process for preparing a precursor sheet formed by mixing a thermosetting resin precursor and the inorganic insulating powder, said precursor
A step of semi-cured by heating the sheet, the precursor sheet was semi-cured, with printing a thermosetting resin precursor and at least two types of single element metal powder and the formed by mixing the metal paste in a predetermined pattern Heating and semi-curing , and semi-curing with the semi-cured metal paste applied
And stacking a plurality of the precursor sheets one above the other
Les heat processing, heat curing of the precursor sheet, and the gold <br/> genus paste with at least two types of single element metal powder of the metal paste to form a metal member by another are joined by alloying step of sexual resin precursor is integrated by thermal curing method for manufacturing a wiring substrate, characterized in that it consists of and.