JPH1013036A - Multilayer wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a wiring conductor as a thin-film wiring conductor formed by the thin-film formation technique, at the same time incorporate a capacitance element inside the conductor for miniaturization, and to provide a multilayer wiring board with a high-density wiring. SOLUTION: A wiring board consists of an insulation substrate 1 with a through hole 5 that penetrates through both upper and lower main surfaces, a conductive layer 6 led from the upper surface of the insulation substrate 1 to the lower surface via the inner wall of the through hole 5, an organic resin filling body 7 filled into the inside of the through hole 6, and a multilayer wiring part 4 deposited at least on one main surface of the insulation substrate 1 and alternately laminated in a plurality of organic resin insulation layers 3a, 3b, and 3c and a plurality of thin-film wiring conductors 4a, 4b, and 4c, and at the same time where one part of the thin-film wiring conductor 4a is electrically connected to the conductive layer 6. In this case, at least the above organic resin insulation layer 3b contains a dielectric material filler with a specific specific dielectric constant being 20 or larger, an organic resin insulation layer 3b containing the dielectric material filler is held oppositely by one portion of the thin-film wiring conductors 4a and 4b being provided on the upper and lower surfaces for forming a capacity element A, and at the same time, the capacitive element A is connected to the thin-film wiring conductors 4a and 4b electrically.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer wiring board, and more particularly to a multilayer wiring board used for a hybrid integrated circuit device, a semiconductor element housing package for housing a semiconductor element, and the like.

[0002]

2. Description of the Related Art Conventionally, a hybrid integrated circuit device which mounts a large number of active components such as semiconductor devices and passive components such as capacitors and resistors to form a predetermined electronic circuit is usually provided with an insulating substrate. A wiring board having a structure in which a wiring conductor made of a high melting point metal powder such as tungsten or molybdenum is formed inside and on the surface is prepared, and then a semiconductor element, a capacitor element, a resistor, and the like are mounted on the surface of the wiring board. At the same time, by connecting an electrode of the semiconductor element or the like to the wiring conductor, a hybrid integrated circuit device is obtained.

[0003] Wiring boards used in such conventional hybrid integrated circuit devices and the like are generally manufactured by employing a ceramic lamination technology and a thick film technology such as a screen printing method, and more specifically, by the following method. Has been produced.

[0004] (1) First, an organic solvent and a solvent are added to and mixed with a ceramic raw material powder such as alumina which is excellent in electrical insulation to obtain a plurality of ceramic green sheets, and the raw ceramic sheets are formed on the upper and lower surfaces of each ceramic raw sheet. A conductive paste composed of a high melting point metal powder such as tungsten or molybdenum is printed and applied in a predetermined pattern by employing a conventionally known thick film method such as a screen printing method.

(2) Each of the above ceramic green sheets is laminated to obtain a laminate, which is fired at a temperature of about 1500 ° C., and a wiring conductor made of a high melting point metal powder such as tungsten, molybdenum or the like inside and on the surface. Is obtained.

(3) Finally, the surface of the wiring conductor exposed to the atmosphere is excellent in corrosion resistance such as nickel and gold, has good conductivity, and has wettability (reactivity) with a brazing material such as solder. A good metal is deposited by a plating method, thereby completing a wiring board as a product.

[0007]

However, in this conventional wiring board, the wiring conductor is formed into a predetermined pattern by applying a conductive paste made of a high melting point metal powder such as tungsten or molybdenum by a screen printing method or the like. It is formed by printing and applying, and has a drawback that it is difficult to miniaturize the wiring conductor and it is not possible to form the wiring conductor at high density.

In addition, the conventional wiring board has a drawback that active components such as semiconductor devices and passive components such as capacitors and resistors are mounted on the surface thereof, and the size thereof increases in accordance with the number of mounted components. Was.

[0009]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and has as its object the purpose of making a wiring conductor a thin film wiring conductor formed by a thin film forming technique and incorporating a capacitive element therein. Accordingly, it is an object of the present invention to provide a multilayer wiring board which is reduced in size and has a high density of wiring.

According to the present invention, there is provided an insulating substrate having a through hole penetrating both upper and lower main surfaces, a conductive layer extending from the upper surface of the insulating substrate to the lower surface through the inner wall of the through hole, and filled in the through hole. The organic resin filler, which is attached on at least one main surface of the insulating substrate, and a plurality of organic resin insulating layers and a plurality of thin film wiring conductors are alternately arranged in a multilayer and a part of the thin film wiring conductor is A multilayer wiring board comprising a multilayer wiring portion electrically connected to a conductive layer, wherein at least one of the organic resin insulating layers contains a dielectric filler having a relative dielectric constant of 20 or more, and the dielectric filler Is formed between the thin film wiring conductors by electrically sandwiching the organic resin insulating layer containing the same between the thin film wiring conductors disposed on the upper and lower surfaces thereof. It is characterized in.

Further, the present invention is characterized in that the dielectric filler has a particle size of at least one of barium titanate and strontium titanate having a diameter of 0.5 μm to 50 μm.

According to the multilayer wiring board of the present invention, since the wiring is formed on the insulating substrate by the thin film forming technique, the wiring can be miniaturized, and the wiring can be formed at an extremely high density.

Further, according to the multilayer wiring board of the present invention, at least one of the organic resin insulating layers contains a dielectric filler having a relative dielectric constant of 20 or more, and the organic resin insulating layer containing the dielectric filler is provided. The capacitive element is formed by opposing and sandwiching a part of the thin film wiring conductors disposed on the upper and lower surfaces thereof, and the capacitive element is electrically connected between the thin film wiring conductors. When a component such as a capacitor and a resistor is mounted to form a hybrid integrated circuit device or the like, it is not necessary to separately mount a large number of capacitors on the multilayer wiring board. As a result, the number of components mounted on the multilayer wiring board is reduced. And the size of the hybrid integrated circuit device and the like can be reduced.

[0014]

Next, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of a multilayer wiring board according to the present invention, wherein 1 is an insulating substrate, and 2 is a multilayer wiring section.

The insulating substrate 1 has three organic resin insulating layers 3a, 3b, 3c and three thin film wiring conductors 4 on its upper surface.
The multilayer wiring portion 2 is formed by alternately arranging a, 4b and 4c in multiple layers, and functions as a support member for supporting the multilayer wiring portion 2.

The insulating substrate 1 is made of an oxide ceramic such as an aluminum oxide sintered body or a mullite sintered body, or an aluminum nitride sintered body having an oxide film on its surface.
It is made of an electrically insulating material such as a non-oxide ceramic such as a silicon carbide sintered body, and a glass epoxy resin in which a cloth woven with glass fibers is impregnated with an epoxy resin. In the case of a compact, a suitable organic solvent and a solvent are added to raw material powders such as alumina, silica, calcia, and magnesia to form a slurry by mixing and adding the same to a conventionally known doctor blade method or calender roll. By forming the ceramic green sheet (ceramic raw sheet) by adopting the method,
Thereafter, the ceramic green sheet is subjected to an appropriate punching process so as to have a predetermined shape and a high temperature (about 16 ° C.).
(00 ° C.) or by mixing a raw material powder such as alumina with an appropriate organic solvent and a solvent to adjust the raw material powder and form the raw material powder into a predetermined shape by a press molding machine. About 1600 ° C
If it is made by firing at a temperature of, and made of glass epoxy resin, for example, impregnating the epoxy resin precursor into a cloth woven of glass fibers and heat curing the epoxy resin precursor at a predetermined temperature Produced by

The insulating substrate 1 is formed with a through hole 5 having a diameter of, for example, 300 μm to 500 μm, which penetrates the upper and lower main surfaces. Conductive layers 6 leading to both sides are applied.

The through hole 5 electrically connects the thin-film wiring conductor 4a of the multilayer wiring portion 2 formed on the upper surface of the insulating substrate 1 to be described later and an external electric circuit, or is formed on both upper and lower main surfaces of the insulating substrate 1. When the multilayer wiring portion 2 is provided, it acts as a forming hole for forming a conductive layer 6 for electrically connecting the thin film wiring conductors of the multilayer wiring portion 2 on both main surfaces, and a drill hole is formed in the insulating substrate 1. A predetermined position and a predetermined shape of the insulating substrate 1 are formed by performing the opening method.

The conductive layer 6 formed on the inner wall of the through hole 5 and on the upper and lower surfaces of the insulating substrate 1 is made of a metal material such as copper or nickel. As a result, the inner wall of the through hole 5 is adhered and formed with both ends being led out to the upper and lower surfaces of the insulating substrate 1.

The conductive layer 6 electrically connects the thin-film wiring conductor 3a of the multilayer wiring portion 2 provided on the main surface of the insulating substrate 1 to an external electric circuit, or is provided on both upper and lower main surfaces of the insulating substrate 1. It functions to electrically connect the thin film wiring conductors of each of the provided multilayer wiring portions 2 to each other.

The through hole 5 formed in the insulating substrate 1 is filled with an organic resin filler 7 made of epoxy resin. The through hole 5 is completely filled with the organic resin filler 7, and Both end surfaces of the organic resin filler 7 are flush with the surface of the conductive layer 6 attached to the upper and lower main surfaces of the insulating substrate 1.

The organic resin filler 7 is provided on the upper and / or lower surface of the insulating substrate 1 with a plurality of organic resin insulating layers 3a to be described later.
3b, 3c and a plurality of layers of thin film wiring conductors 4a, 4b, 4c
When the multi-layer wiring portion 2 is formed, each organic resin insulating layer 3a, 3b, 3c of the multi-layer wiring portion 2 and each thin-film wiring conductor 4
a, 4b, and 4c maintain the flatness.

The organic resin filler 7 fills the through-hole 5 of the insulating substrate 1 with an epoxy resin precursor, and then is applied with a temperature of 80 ° C. to 200 ° C. for 0.5 to 3 hours. Then, it is completely filled in the through holes 5 of the insulating substrate 1 by thermosetting.

Further, the insulating substrate 1 has a multilayer wiring portion 2 in which three organic resin insulating layers 3a, 3b, 3c and three thin-film wiring conductors 4a, 4b, 4c are alternately arranged on the upper surface. The thin film wiring conductor 4 a is formed and is electrically connected to the conductive layer 6.

The organic resin insulating layers 3a, 3b and 3c constituting the multilayer wiring section 2 are composed of thin film wiring conductors 4 located above and below.
The thin film wiring conductors 4a, 4b, and 4c serve as transmission paths for transmitting electric signals.

Each organic resin insulating layer 3 of the multilayer wiring section 2
a, 3b and 3c are made of an epoxy resin. For example, when made of an epoxy resin, bisphenol A type epoxy resin, novolak type epoxy resin, glycidyl ester type epoxy resin, etc. are used as an amine-based curing agent, an imidazole-based curing agent, and an acid anhydride. A curing agent such as a system curing agent is added and mixed to obtain a paste-like epoxy resin precursor, and the epoxy resin precursor is applied to the upper part of the insulating substrate 1 by a spin coating method. It is formed by heat-treating with heat of about 200 ° C. for 0.5 to 3 hours and heat-curing.

Each of the organic resin insulating layers 3a, 3b, 3
As for c, a through hole 8 whose minimum diameter is about 1.5 times the thickness of the organic resin insulating layer is formed at a predetermined position of each of the organic resin insulating layers 3a, It functions as a forming hole for forming a through-hole conductor 9 that electrically connects each of the thin film wiring conductors 4a, 4b, and 4c located above and below via 3b and 3c.

The through holes 8 provided in each of the organic resin insulating layers 3a, 3b, 3c are formed, for example, by photolithography, specifically, by coating a resist material on each of the organic resin insulating layers 3a, 3b, 3c. A window having a predetermined shape is formed at a predetermined position by performing exposure and development, and then an etchant is disposed on the window of the resist material, and the organic resin insulating layers 3a, 3b, 3c
Is removed to form holes (through holes) in the organic resin insulating layers 3a, 3b, 3c, and finally, the resist material is peeled off from the organic resin insulating layers 3a, 3b, 3c and removed.

Further, each of the organic resin insulating layers 3a, 3b, 3
c on the upper surface of each of the thin film wiring conductors 4a of a predetermined pattern,
4b and 4c are the respective organic resin insulating layers 3a, 3b and 3c.
The through hole conductor 9 is provided on the inner wall of the through hole 8
Are disposed, and the through-hole conductors 9 electrically connect the thin film wiring conductors 4a, 4b, and 4c located vertically above and below the organic resin insulating layers 3a, 3b, and 3c, respectively. It has become.

The thin film wiring conductors 4 provided on the upper surfaces of the organic resin insulating layers 3a, 3b, 3c and in the through holes 8
a, 4b, 4c and the through-hole conductor 9 are formed by employing a metal material such as copper, nickel, gold, and aluminum by using a thin film forming technique such as an electroless plating method, a vapor deposition method, and a sputtering method and an etching processing technique; For example, when formed of copper, each of the organic resin insulating layers 3a,
0.06 mol / l of copper sulfate, 0.3 mol / l of formalin, 0.35 mol / l of sodium hydroxide, 0.35 mol / l of ethylenediaminetetraacetic acid on the upper surfaces of 3b and 3c and the inner surface of through hole 8 A copper layer having a thickness of 1 μm to 40 μm is deposited by using an electroless copper plating bath, and then the copper layer is processed into a predetermined pattern by an etching method, whereby each of the organic resin insulating layers 3a, 3b, and 3c is formed. Between and each organic resin insulating layer 3a, 3
b, 3c are disposed on the inner wall of the through hole 8. In this case, since the thin film wiring conductors 4a, 4b, and 4c are formed by a thin film forming technique, the wiring can be miniaturized, whereby the thin film wiring conductors 4a, 4b, and 4c can be formed at an extremely high density. Becomes

When the thickness of each of the organic resin insulating layers 3a, 3b and 3c exceeds 100 μm, the through-holes 8 are formed in the multilayer wiring section 2 by adopting a photolithography technique for each of the organic resin insulating layers 3a, 3b and 3c. When forming a through hole, the etching processing time becomes longer and the through hole 8 is formed.
Is difficult to form into a desired clear shape, and if it is less than 5 μm, each organic resin insulating layer 3a, 3b, 3c
When roughening is performed to increase the bonding strength of the organic resin insulating layers located above and below on the upper surface of each of the organic resin insulating layers 3a,
Unnecessary holes are formed in 3b and 3c, and there is a danger that unnecessary electrical short circuits may be caused in the thin film wiring conductors 4a, 4b and 4c located above and below. Therefore, each of the organic resin insulating layers 3a, 3b and 3c has a thickness of 5 μm.
It is preferable to set the range of m to 100 μm.

Each thin-film wiring conductor 4 of the multilayer wiring section 2
When the thickness of each of the thin film wiring conductors 4a, 4b, and 4c is less than 1 μm, the electric resistance of each thin film wiring conductor 4a, 4b, and 4c becomes large, and a predetermined electric signal can be transmitted to each thin film wiring conductor 4a, 4b, and 4c. When the thickness exceeds 40 μm, when the thin film wiring conductors 4a, 4b, and 4c are applied to the organic resin insulating layers 3a, 3b, and 3c, a large stress is generated in the thin film wiring conductors 4a, 4b, and 4c. The thin film wiring conductors 4a, 4b, and 4c are inherently separated from the organic resin insulating layers 3a, 3b, and 3c by the intrinsic stress.
Therefore, each of the thin film wiring conductors 4a, 4a,
It is preferable to set the thickness of b and 4c in the range of 1 μm to 40 μm.

The surface of the thin film wiring conductors 4a, 4b, 4c has a center line average roughness (Ra) of 0.05 μm ≦ R
a ≦ 5 μm, the count value of the height of irregularities (Pc) at a length of 2.5 mm on the surface is 0.01 μm ≦ Pc ≦ 0.1
30000 μm or more, 3000 μm to 10000 μm ≦ Pc ≦ 1 μm, 1 μm ≦ Pc ≦ 10 μm
Is roughened to be 500 or less, each organic resin insulating layer 3a, 3b, 3c and each thin film wiring conductor 4a, 4b, 4
c has a very large bonding area, and as a result, the adhesion between each organic resin insulating layer 3a, 3b, 3c and each thin film wiring conductor 4a, 4b, 4c is remarkably improved, and the organic resin insulating layer 3a, 3b, 3c and thin film wiring conductors 4a, 4b,
Even if an external force is applied to 4c, each organic resin insulating layer 3a, 3b, 3c and each thin film wiring conductor 4a, 4b, 4c
No separation occurs between the two and c, and the bonding between the two can be made extremely strong. Accordingly, the surface of each of the thin film wiring conductors 4a, 4b, 4c has a center line average roughness (R
In a) 0.05 μm ≦ Ra ≦ 5 μm, 2.5 mm on the surface
The count value of the height (Pc) of the unevenness in the length of.
30 μm or more of 0.01 μm ≦ Pc ≦ 0.1 μm;
1 μm ≦ Pc ≦ 1 μm is 3000 to 10000,
It is preferable that 1 μm ≦ Pc ≦ 10 μm is roughened so as to be 500 or less.

Further, the organic resin insulating layers 3a, 3b,
3c and the thin film wiring conductors 4a, 4b, 4c, the wiring conductor portion 2 includes a dielectric filler having a relative dielectric constant of 20 or more in the organic resin insulating layer 3b, and the organic resin insulating layer 3b is provided on both upper and lower surfaces thereof. The capacitive element A is formed by being sandwiched between a part of the disposed thin film wiring conductors 4a and 4b, and the capacitive element A is electrically connected to the thin film wiring conductors 4a and 4b.

The capacitance value of the capacitor A is determined by the relative dielectric constant of the organic resin insulating layer 3b containing a dielectric filler having a relative dielectric constant of 20 or more, the thickness of the organic resin insulating layer 3b, and the thickness of the thin film wiring conductor. The predetermined electrostatic capacity is determined by the size of the opposing area of the thin film wiring conductors 4a and 4b, and is determined by the size of the opposing area of the organic resin insulating layer 3b. Adjusted to the capacitance value.

The capacitive element A is built in the multilayer wiring section 2 provided on the insulating substrate 1. Therefore, components such as a semiconductor element, a capacitive element and a resistor are mounted on the multilayer wiring board and mixedly integrated. In the case of a circuit device or the like, it is not necessary to separately mount a large number of capacitive elements on a multilayer wiring board.
The number of components mounted on the multilayer wiring board is reduced, and the size of the hybrid integrated circuit device or the like can be reduced.

It should be noted that the dielectric filler is contained in the organic resin insulating layer 3b when the organic resin precursor such as an epoxy resin is used to form the organic resin insulating layer 3b. Is contained in the organic resin insulating layer 3b by adding and mixing.

The dielectric filler contained in the organic resin insulating layer 3b has a relative dielectric constant of 20 (room temperature 1 MHz).
When the value is less than the specific dielectric constant of the organic resin insulating layer 3b, the capacitance value of the capacitor A becomes a small value that is not practically used. Therefore, the dielectric filler contained in the organic resin insulating layer 3b has a relative dielectric constant of 20 (room temperature 1).
MHz) or more, and a material having a high relative dielectric constant, such as barium titanate or strontium titanate, is suitably used.

Further, when the particle size of the dielectric filler is less than 0.5 μm in diameter, the specific surface area of the dielectric filler increases, and the viscosity of the organic resin precursor added and mixed with the dielectric filler increases, As a result, when the organic resin precursor to which the dielectric filler is added and mixed is used to form the organic resin insulating layer 3b by spin coating or the like, the thickness of the organic resin insulating layer 3b becomes non-uniform, It is difficult to make the thickness of the capacitor 3b a predetermined uniform thickness. If the thickness exceeds 50 μm, irregularities are formed on the surface of the organic resin insulating layer 3b by the dielectric filler, and the capacitor A
The relative dielectric constant of the organic resin insulating layer 3b varies in the region where the layer is formed, the adhesive strength of the dielectric filler in the organic resin insulating layer 3b decreases, and the dielectric filler drops off from the organic resin insulating layer 3b. There is a risk that Therefore, the dielectric filler preferably has a particle diameter in a range of 0.5 μm to 50 μm.

Further, the content of the dielectric filler in the organic resin insulating layer 3b is such that when the amount of the dielectric filler is less than 20% by weight based on the total organic resin content of the organic resin insulating layer 3b, Has a small relative dielectric constant, making it difficult to form a capacitive element A that can be put to practical use.
If the content exceeds 75% by weight, the adhesive strength of the dielectric filler in the organic resin insulating layer 3b decreases, and there is a risk that the dielectric filler may fall off the organic resin insulating layer 3b.
Therefore, the content of the dielectric filler in the organic resin insulating layer 3b is preferably set in the range of 20% by weight to 75% by weight.

Thus, according to the multilayer wiring board of the present invention,
For example, a hybrid integrated circuit device is obtained by mounting active components such as a semiconductor device, passive components such as a capacitor, and a resistor on the multilayer wiring portion 2 attached to the upper surface of the insulating substrate 1. Is connected to an external electric circuit, the hybrid integrated circuit device is electrically connected to the external electric circuit.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. A plurality of organic resin insulating layers 3a only on the upper surface of
Although the multilayer wiring portion 2 including the thin film wiring conductors 3a and 3b and the plurality of thin film wiring conductors 4a, 4b and 4c is provided, the multilayer wiring portion 2 may be provided only on the lower surface side of the insulating substrate 1 or may be provided on both upper and lower main surfaces. It may be provided.

[0043]

According to the multilayer wiring board of the present invention, since the wiring is formed on the insulating substrate by the thin film forming technique, the wiring can be miniaturized and the wiring can be formed at an extremely high density. .

According to the multilayer wiring board of the present invention, at least one of the organic resin insulating layers contains a dielectric filler having a relative dielectric constant of 20 or more, and the organic resin insulating layer containing the dielectric filler is provided. The capacitive element is formed by opposing and sandwiching a part of the thin film wiring conductors disposed on the upper and lower surfaces thereof, and the capacitive element is electrically connected between the thin film wiring conductors. When a component such as a capacitor and a resistor is mounted to form a hybrid integrated circuit device or the like, it is not necessary to separately mount a large number of capacitors on the multilayer wiring board. As a result, the number of components mounted on the multilayer wiring board is reduced. And the size of the hybrid integrated circuit device and the like can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a multilayer wiring board of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulating board 2 ... Multilayer wiring part 3a, 3b, 3c ... Organic resin insulating layer 4a, 4b, 4c ... Thin film wiring conductor 5 ... Through-hole 6 ... Conductive layer 7 ... Organic resin filler A: Capacitance element

Claims (3)

[Claims] An insulating substrate having a through hole penetrating both upper and lower main surfaces, a conductive layer extending from an upper surface of the insulating substrate to a lower surface via an inner wall of the through hole, and an organic resin filled in the through hole A filler and a plurality of organic resin insulating layers and a plurality of thin film wiring conductors are alternately disposed on the at least one main surface of the insulating substrate, and a part of the thin film wiring conductor is formed on the conductive layer. A multilayer wiring board comprising a multilayer wiring portion electrically connected to the organic resin insulating layer, wherein at least one of the organic resin insulating layers contains a dielectric filler having a relative dielectric constant of 20 or more, and the dielectric filler contains The capacitor element is formed by sandwiching the organic resin insulating layer formed between the thin film wiring conductors disposed on the upper and lower surfaces thereof, and the capacitor element is electrically connected between the thin film wiring conductors. Especially Multilayer wiring substrate having a. 2. The method according to claim 1, wherein the dielectric filler is barium titanate;
2. The multilayer wiring board according to claim 1, comprising at least one of strontium titanate. 3. The dielectric filler has a particle diameter of 0.5 μm.
3. The multilayer wiring board according to claim 1, wherein the thickness of the multilayer wiring board is in a range of m to 50 μm.