JP3164751B2 - Multilayer thin film wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, a wiring board used for a hybrid integrated circuit device, a package for housing a semiconductor element, or the like has a circuit wiring formed by a thick film forming technique such as a Mo-Mn method.

In the Mo-Mn method, an organic solvent and a solvent are added to a metal powder composed of a high melting point metal such as tungsten, molybdenum, and manganese to form a paste-like metal paste on the outer surface of a raw or sintered ceramic body. In this method, a predetermined pattern as circuit wiring is printed and applied by screen printing, and then fired in a reducing atmosphere to sinter and integrate the high melting point metal powder and the ceramic body.

However, when the circuit wiring is formed by using the Mo-Mn method, the circuit wiring is formed by screen-printing a metal paste, so that it is difficult to miniaturize the circuit wiring. There was a disadvantage that the density could not be increased.

In order to solve the above-mentioned disadvantages, a multilayer thin-film wiring board formed by using a thin-film forming technique capable of miniaturization is used instead of forming a circuit wiring by a conventional thick-film forming technique. It has become.

A multilayer thin film wiring board in which the circuit wiring is formed by a thin film forming technique is usually made of an aluminum oxide sintered body, a mullite sintered body, a silicon carbide sintered body, an aluminum nitride sintered body, a glass ceramic. It has a structure in which a circuit wiring film made of aluminum, copper, chromium, nickel, etc. and an insulating film made of an organic polymer material such as polyimide are alternately applied in multiple layers on an insulating substrate made of a sintered body or the like. If the electrodes such as semiconductor elements and capacitors are connected to the circuit wiring film via solder, each electronic component such as the semiconductor elements and capacitors is electrically connected to each other via the circuit wiring film. Has become.

[0007]

However, in the multilayer thin-film wiring board, external lead terminals are attached to the circuit wiring film by using a brazing material made of a gold-tin alloy or the like generally used in the prior art. Is electrically connected to another external electric circuit through an external lead terminal, the brazing material made of a gold-tin alloy or the like has a thermal expansion coefficient of 18 × 10 ⁻⁶ / ° C.
On the other hand, the thermal expansion coefficient of the insulating film made of an organic polymer such as polyimide on the circuit wiring film is 40 × 1.
0 ⁻⁶ / ° C. to 50 × 10 ⁻⁶ / ° C., which greatly differs from each other, so that the brazing material is insulated between the brazing material for attaching the external lead terminals and the circuit wiring film attached to the insulating film. A large stress is generated due to the difference in the coefficient of thermal expansion of the film, and this stress induces a disadvantage that the reliability of attaching the external lead terminal to the circuit wiring film is greatly reduced.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and has as its object to firmly attach an external lead terminal to a circuit wiring film and to connect an electronic component connected to the circuit wiring film to another external electric device. It is an object of the present invention to provide a multilayer thin-film wiring board that can reliably be electrically connected to a circuit.

[0009]

According to the present invention, an insulating film made of an organic polymer material and a circuit wiring film made of a metal material are alternately laminated in multiple layers on an insulating substrate by a thin film forming technique. A multilayer thin-film wiring board having external lead terminals attached thereto via a brazing material, wherein the thermal expansion coefficient of an insulating film in contact with a circuit wiring film to which the external lead terminals are attached via the brazing material is 10 × 10 ^-6 / ° C to 30 × 1
^0-4 / ° C., and the insulating film in contact with the circuit wiring film to which the external lead terminal is to be brazed is 4,4 ′ containing 20% by weight of a polyimide obtained from P-phenylenediamine and pyromellitic anhydride. -Is formed of a copolymer of diaminodiphenyl ether and a polyimide obtained from pyromellitic anhydride.

[0010]

[0011]

According to the multilayer thin film wiring board of the present invention, the thermal expansion coefficient of the insulating film in contact with the circuit wiring film to which the external lead terminals are to be brazed is 10 × 10 ⁻⁶ / ° C. to 30 × 10 ⁻⁶ / ° C. And 4,4′-diaminodiphenyl ether containing 20% by weight of a polyimide obtained from P-phenylenediamine and pyromellitic anhydride, and an insulating film in contact with a circuit wiring film to which an external lead terminal is to be brazed, and pyromellitic acid Formed from a copolymer with polyimide obtained from an anhydride, the external lead terminals were attached to the circuit wiring film. When the circuit wiring film is electrically connected to another external electric circuit via the external lead terminals, the circuit attached to the brazing material for attaching the external lead terminals and the insulating film is attached. There is no large stress generated between the wiring film and the thermal expansion coefficient between the brazing material and the insulating film. As a result, the external lead terminals are firmly attached to the circuit wiring film and connected to the circuit wiring film. It is possible to reliably electrically connect the electronic component to be connected to another external electric circuit via the external lead terminal.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 shows an embodiment of a multilayer thin film wiring board according to the present invention, wherein 1 is an insulating substrate, 2 is a circuit wiring film, and 3 is an insulating film.

The insulating substrate 1 is made of an electrically insulating material such as an aluminum oxide sintered body, a mullite sintered body, a silicon carbide sintered body, an aluminum nitride sintered body, a glass ceramic sintered body, etc. Is covered with a multilayer wiring portion A including a circuit wiring film 2 and an insulating film 3.

The insulating substrate 1 functions as a supporting member for supporting the multilayer wiring portion A. For example, when the insulating substrate 1 is made of an aluminum oxide sintered body, an organic material suitable for a raw material powder such as alumina, silica, magnesia, and calcia is used. A solvent and a solvent are added and mixed to form a slurry, which is then formed into a ceramic green sheet (raw ceramic sheet) by employing a doctor blade method, a calender roll method, or the like. It is manufactured by punching, forming a predetermined shape, and firing at a high temperature (about 1600 ° C.).

The multilayer wiring portion A attached to the upper surface of the insulating substrate 1 is formed by alternately stacking the circuit wiring films 2 and the insulating films 3 in multiple layers. When electronic components such as the semiconductor element 4 and the capacitor 5 are connected via solder, the electronic components such as the semiconductor element 4 and the capacitor 5 are electrically connected via the circuit wiring film 2.

The circuit wiring film 2 of the multilayer wiring portion A is made of a metal material such as aluminum, copper, chromium, nickel or the like, and is insulated by employing a thin film forming technique such as a vapor deposition method or a sputtering method and an etching technique. On the substrate 1, a multi-layer is formed with an insulating film 3 interposed therebetween.
In this case, since the circuit wiring film 2 is formed by a thin film forming technique, the circuit wiring film 2 can be miniaturized, and the circuit wiring film 2 can be formed at a high density.

The circuit wiring film 2 has a thickness of 0.5
If it is less than μm, the electric resistance of the circuit wiring film 2 tends to be large, and if it exceeds 20 μm, the circuit wiring film 2 is less than the insulating film 3 due to internal stress when the circuit wiring film 2 is formed by the thin film forming technique. The thickness is preferably in the range of 0.5 μm to 20 μm, and preferably 1 μm to 20 μm.
μm to 10 μm thickness, optimally 2 μm to 5 μm
It is good to keep the thickness.

An external lead terminal 6 is attached to the uppermost one of the circuit wiring films 2 via a brazing material 7 such as a gold-tin alloy. Semiconductor element 4 and capacitor 5 connected to film 2
And the like to electrically connect such electronic components to other external electric circuits.

The external lead terminals 6 are formed of a metal material such as an iron-nickel-cobalt alloy, an iron-nickel alloy, or copper. It is formed into a predetermined shape by performing a conventionally known metal working such as a punching method.

Further, an insulating film 3 is disposed between the circuit wiring films 2, and the insulating film 3 has a function of maintaining electrical insulation of the circuit wiring films 2 located above and below.

The insulating film 3 is made of an organic polymer material such as a polyimide resin. For example, 50 mol% of 4,4′-diaminodiphenyl ether,
A polymer solution containing 0 mol% of 3,3′-biphenyltetracarboxylic dianhydride is applied onto the insulating substrate 1 by a spin coating method, and then heated at about 400 ° C. to heat the polymer solution. By cross-linking, it is formed between the circuit wiring films 2 on the insulating substrate 1.

The thickness of the insulating film 3 is 0.5 μm.
If it is less than 3, a pinhole is generated in the insulating film 3 and the insulating film 3
There is a tendency that it is difficult to achieve electrical insulation between the circuit wiring films 2 formed above and below the insulating film 3. If the thickness exceeds 40 μm, the insulating film 3 may be damaged due to internal stress when the insulating film 3 is formed. The thickness is preferably in the range of 0.5 μm to 40 μm, and more preferably 2.
5 μm to 20 μm thickness, optimally 5 μm to 15 μm
It is good to keep the thickness of μm.

Further, the thermal expansion coefficient of the insulating film 3a of the insulating film 3 that contacts at least the circuit wiring film 2 to which the external lead terminals 6 are attached via the brazing material 7 is 10 × 10 ⁻⁶ / ° C.
To 30 × 10 ⁻⁶ / ° C., so that even when the external lead terminals 6 are attached to the circuit wiring film 2 using the brazing material 7, the brazing material 7 for attaching the external lead terminals 6 and the insulating film 3a
No large stress is generated between the circuit material 2 and the circuit wiring film 2 due to the difference in the thermal expansion coefficient between the brazing material 7 and the insulating film 3a. The electronic components such as the semiconductor element 4 and the capacitor 5 which are firmly attached to the circuit wiring film 2 and connected to the circuit wiring film 2 can be reliably electrically connected to other external electric circuits via the external lead terminals 6. Become.

In the insulating film 3, at least the insulating film 3a in contact with the circuit wiring film 2 to which the external lead terminals 6 are attached via the brazing material 7 is made of, for example, P-phenylenediamine and pyromellitic anhydride. The resulting polyimide is 20
It is formed of a copolymer of 4,4'-diaminodiphenyl ether containing 4% by weight and a polyimide obtained from pyromellitic anhydride, and a polymer solution is applied onto the insulating substrate 1 by a spin coating method. The external lead terminals 6 are disposed under the circuit wiring film 2 to be attached via the brazing material 7 by applying heat of about 400 ° C. to thermally crosslink the polymer solution.

The insulating film 3a in contact with the circuit wiring film 2 to which the external lead terminals 6 are attached via the brazing material 7 has a thermal expansion coefficient of less than 10 × 10 ⁻⁶ / ° C. or 30 × 1.
If the temperature exceeds 0 ^-6 / ° C., the difference in the thermal expansion coefficient between the brazing material 7 and the insulating film 3a between the brazing material 7 for attaching the external lead terminal 6 and the circuit wiring film 2 provided on the insulating film 3a. As a result, a large thermal stress is generated, and the external lead terminals 6 cannot be firmly attached to the circuit wiring film 2. Accordingly, the circuit wiring film 2 to which the external lead terminals 6 are attached via the brazing material 7
Has a thermal expansion coefficient of 10 × 10 ⁻⁶ /
It is specified in the range of 30 ° C. to 30 × 10 ⁻⁶ / ° C.

Thus, according to the above-described multilayer thin film wiring board, electronic components such as the semiconductor element 4 and the capacitor 5 are connected to the circuit wiring film 2 of the multilayer wiring portion A attached on the upper surface of the insulating substrate 1 via solder. Then, the electronic components such as the semiconductor element 4 and the capacitor 5 are electrically connected to each other via the circuit wiring film 2, and if the external lead terminals 6 are connected to another external electric circuit board, the semiconductor element 4 and the capacitor 5 Such electronic components are electrically connected to an external electric circuit board via the external lead terminals 6.

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 scope of the present invention. If a metal having excellent corrosion resistance, such as nickel and gold, and a good wettability with a brazing material is applied to the surface of the surface to a thickness of 0.1 μm to 20 μm by a plating method, the oxidative corrosion of the external lead terminals 6 can be effectively prevented. In addition, the connection between the external lead terminals 6 and the external electric circuit board can be improved. Therefore, the external lead terminal 6 is made of nickel, gold,
It is preferable that it is applied to a thickness of μm.

[0028]

[0029]

According to the multilayer thin film wiring board of the present invention, the thermal expansion coefficient of the insulating film in contact with the circuit wiring film to which the external lead terminals are to be brazed is 10 × 10 ⁻⁶ / ° C. to 30 × 10 ⁻⁶ /.
° C and the insulating film in contact with the circuit wiring film to which the external lead terminals are to be brazed is 20% by weight of a polyimide obtained from P-phenylenediamine and pyromellitic anhydride.
It was formed from a copolymer of the contained 4,4'-diaminodiphenyl ether and a polyimide obtained from pyromellitic anhydride, and approximated to the thermal expansion coefficient of a brazing material for attaching external lead terminals to a circuit wiring film. Therefore, when an external lead terminal is attached to the circuit wiring film using a brazing material and the circuit wiring film is electrically connected to another external electric circuit via the external lead terminal, the external lead terminal is removed. No large stress is generated between the brazing material to be attached and the circuit wiring film attached to the insulating film due to the difference in the coefficient of thermal expansion between the brazing material and the insulating film. The electronic components firmly attached to the wiring film and connected to the circuit wiring film can be reliably electrically connected to other external electric circuits via external lead terminals.

[Brief description of the drawings]

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulating board 2 ... Circuit wiring film 3 ... Insulating film 6 ... External lead terminal 7 ... Brazing material A ... .... Multilayer wiring part

Claims (1)

(57) [Claims] 1. A with laminated in multiple layers alternating with more comprising an organic polymer material insulating film and the circuit wiring film made of a metal material film forming technique on an insulating substrate, a row of external lead terminals to the circuit wiring film a multilayer thin film wiring board formed by attaching via the timber, the thermal expansion coefficient of the insulating film before Kigai unit lead terminal in contact with the circuit wiring film which is attached via a brazing material 1
0 × 10 ^-6 / ℃ to prior as well as a 30 × 10 ^-6 / ℃
Contact with the circuit wiring film to be soldered to the external lead terminal
Insulation film without P-phenylenediamine and pyromellitic acid
4, containing 20% by weight of polyimide obtained from water
4'-diaminodiphenyl ether and pyromellitic acid
Formed with a copolymer with polyimide obtained from anhydride
Multilayer thin film wiring board, characterized by that.