JPH0767013B2 - Electronic circuit parts - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit board on which, for example, an integrated circuit (IC) or the like is mounted, or an electronic device preferably used for a package in which a semiconductor integrated circuit element is stored, for example. Regarding circuit parts.

2. Description of the Related Art In recent years, in circuit wiring boards and the like, the miniaturization and high density of the circuit wiring formed have been improved more and more. Therefore, the circuit wiring board manufacturing technology has been developed to meet such demand. .

As a first conventional technique for manufacturing such a circuit wiring board, a high melting point metal material such as molybdenum or tungsten is screen-printed on a base material made of, for example, alumina-based ceramics, and then, for example, 1500
A technique for baking at a temperature of about ℃ is known.

In such a conventional technique, since the screen printing technique is used to form the circuit wiring, the width of the circuit wiring is required to be at least about 100 μm, and therefore, there is a limitation on miniaturization and high density of the circuit wiring board. There is a problem that it will be done. Another problem with this conventional technique is that the ceramics used for the base material have an extremely high dielectric constant of, for example, about 10, making high-speed signal propagation difficult due to the resistance in the circuit. There is a problem in that high-speed operation of an electronic circuit or the like configured using is impossible.

As a second conventional technique for solving such a problem, for example, a polyimide film is formed on a base material such as ceramics, a metal material is vapor-deposited on the polyimide film, and thereafter, a circuit having a desired pattern is formed by etching. A technique is used in which wiring is formed and this step is repeated to form a single-layer or multilayer circuit wiring board.

Compared with the above-mentioned first conventional technique, such a conventional technique has an advantage that the width of the circuit wiring can be narrowed to about 25 μm, and miniaturization and high density of the circuit wiring board can be improved.
Further, the polyimide film that realizes electrical insulation between circuit wirings has a relatively small dielectric constant of 3 to 3.5, so that the signal propagation speed can be increased as compared with the case where the first conventional technique is used, and an electronic circuit configured. The processing speed of can be improved.

In addition, for example, integrated circuits (ICs) and large scale integrated circuits (LS
I), in an electronic circuit board on which a hybrid integrated circuit or the like is mounted, a polyimide resin is used for a structure including a conductor layer and its interlayer insulating film or a protective film, or for a package in which, for example, a semiconductor integrated circuit element is stored. A technique of forming a metal thin film on the wiring as a circuit wiring is widely used. Polyimide resin has relatively high heat resistance and low dielectric constant among polymers from the viewpoint of electrical insulation, and is known to have wide resistance to various processing such as vapor deposition and plating. .

On the other hand, such a second conventional technique has a problem that the reliability of the adhesion strength between the polyimide resin film and the circuit wiring is unduly low. The indication of this problem will be described in detail in the section of Examples to be described later as experimental results regarding comparative examples to be compared with the present invention, but the outline thereof will be given below.
For example, circuit wiring made of metal materials such as chromium, molybdenum, titanium, etc.
It was confirmed that due to the oxidation of the circuit wiring metal, the adhesion strength between the polyimide resin and the circuit wiring metal was reduced from 5 kg / mm ² to 1 kg / mm ² after being left for about 100 hours.

That is, conventionally, generally used polyimide resin, the general formula, And the functional group R1 is, for example, And the functional group R2 is, for example, Is. As a typical example, a polyimide resin having the following structural formula is generally used.

The conventionally used types of functional groups shown above are electron-donating, and due to the thermally unstable bond state between such functional groups and metal atoms, Things are happening.

That is, the polyimide resin and the metal are in close contact with each other by a chemical bond of —C—O— metal or —C—metal, which is formed by donating outer shell electrons of the metal to the carbonyl group portion of the polyimide resin. With conventional polyimide resin, The fact that the electron density of the structure is low was confirmed by the present inventors. This fact is due to the fact that XPS (X-ray Photoelectron Spe
Confirmed by ctroscope (ESCA) analysis.

In the manufacturing process of the circuit wiring substrate as described above, a photolithography process and a curing process for forming a polyimide precursor into a polyimide structure are adopted, and these include various heat treatment processes. Further, the heat treatment step is included in the step of packaging the semiconductor integrated circuit element, and a heat generation phenomenon is observed during the operation of the integrated circuit as a product. Therefore, when the adhesion strength between the polyimide resin and the metal layer such as the circuit wiring is deteriorated under such a thermal environment, the circuit wiring is broken or the semiconductor integrated circuit element is peeled from the package. It will be a serious situation.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention has been made in view of the above-described problems, and significantly improves the reliability of the adhesion strength between a polyimide resin and a metal thin film, and is a thermal environment. Another object of the present invention is to provide an electronic circuit component whose reliability is significantly improved.

Means for Solving the Problems The present invention is an electronic circuit component formed by forming a metal thin film on a polyimide resin formed on the surface of a base material, wherein the polyimide resin is represented by the general formula: Is selected, and at least one of the functional groups R1 and R2 is an electron-withdrawing group, which is an electronic circuit component.

In a preferred embodiment of the present invention, the electron-withdrawing group is represented by the general formula: It is characterized by being selected from the types represented by.

In another preferred embodiment, at least the surface of the metal thin film in contact with the polyimide resin is at least one of molybdenum (Mo), chromium (Cr), titanium (Ti), and tungsten (W), or two of them. It is characterized by being composed of one or more kinds of alloys.

Still another preferred embodiment is characterized in that at least one of ceramics, glass, and metal is selected as the base material.

Yet another preferred embodiment, the polyimide resin layer,
It is characterized in that it is formed in a layer thickness of 2 to 50 μm.

In yet another preferred embodiment, the metal thin film has a thickness of 250-4.
It is characterized by being formed in 000Å.

In yet another preferred embodiment, the portion of the metal thin film that does not contact the polyimide resin layer is aluminum (Al), copper (C
At least one of u) and gold (Au) is selected.

Operation According to the present invention, the polyimide resin layer is formed on the surface of the base material forming the electronic circuit component, and the metal thin film is formed on the layer. At this time, the polyimide resin has the following general formula, The type represented by is selected. Further, in the above structural formula, at least one of the functional groups R1 and R2 is selected as an electron-withdrawing group.

Thus, in the polyimide resin having the functional groups R1 and R2 selected as the electron-withdrawing group, the above general structural formula It was confirmed by the present inventors that the electron density in the structure portion is low. This is XPS (X-ray Photoelectron
Confirmed by Spectroscope (ESCA) analysis method.
In such a case, the structural portion of the polyimide resin represented by the second formula easily receives electrons from the metal atoms of the metal thin film formed on the polyimide resin layer. Therefore, the polyimide resin and the metal are A polyimide resin having a ≡C-O-M structure or a ≡C-M structure chemical bond formed by the outer shell electron being donated to the carbonyl group of the polyimide, and the bond energy having the functional group described in the section of the prior art. It will be much higher. Therefore, even in a high-temperature oxygen atmosphere, the bond between the polyimide resin and the metal is not broken, and the reliability of the adhesion strength is dramatically improved.

In the structure of the polyimide resin used in the present invention represented by the first formula, at least one of the functional groups R1 and R2 is an electron-withdrawing group represented by the following general formula. Chosen from among.

Further, in the metal thin film formed on the polyimide resin layer, at least the surface in contact with the polyimide resin layer is at least one of molybdenum (Mo), chromium (Cr), titanium (Ti), and tungsten (W), or the like. It is formed from an alloy of two or more of Such a kind of metal constitutes aluminum (Al), copper (C
It has been confirmed that the adhesion strength to the polyimide resin layer is higher than that of u) and gold (Au).

This polyimide resin layer uses a polyimide resin precursor described later, is applied to the surface of the substrate by the so-called spinner method or spray method, and by heat treatment at 300 ℃ ~ 400 ℃, having a polyimide structure 2 ~ 50μm
To form a film thickness of. Next, through holes for connection in the case of forming a multilayer structure are formed by photolithography or the like.

The metal thin film formed on this is applied on the polyimide resin layer by using a sputtering method, an ion plating method or the like, and is etched by the photolithography technique. At this time, the photoresist layer used as a mask is peeled and removed. As a result, a desired circuit wiring pattern is realized. By repeating such steps, a multilayer wiring circuit board can be realized.

Example (I) Manufacturing process of circuit board 1 FIG. 1 shows a multilayer wiring circuit board (hereinafter, referred to as an embodiment of the present invention).
2 is a cross-sectional view of a circuit board 1). Referring to FIG. 1, a circuit board 1 includes an insulating substrate 2 made of, for example, a slurry material, on which a first wiring layer 3 having a structure described below is formed, and a polyimide resin formed on the first wiring layer 3. It is connected to the second wiring layer 6 at a desired position through the through hole 5 of the layer 4. The second wiring layer 6 and the first wiring layer 3
Are basically insulated by the polyimide resin layer 4.

Further, the polyimide resin layer 7 is formed on the second wiring layer 6, and the third wiring layer 9 is connected to the second wiring layer 6 at a desired position through the through hole 8 of the polyimide resin layer 7. The combination of such wiring layers 3 and 6 and the polyimide resin layers 4 and 7 formed thereon will be described as two layers in this embodiment, but in general, even if a multilayer structure having three or more layers is used, Are performed similarly.

FIG. 2 is a sectional view taken along the section line II-II in FIG. Referring to FIG. 2, the second wiring layer 6 sandwiched between the polyimide resin layers 4 and 7 is composed of the adhesive layers 10 and 11 which are the surfaces on the side in contact with the polyimide resins 4 and 7 and the adhesive layers 10 and 11. The wiring layer 12 is formed between them. The adhesion layers 10 and 11 are made of at least one element of molybdenum, chromium, titanium, or tungsten, or an alloy of two or more of these elements. In this embodiment, the adhesion layer 10 is made of molybdenum Mo alone, and the adhesion layer 11 is made of chromium Cr alone. The wiring layer 12 is made of at least one of aluminum Al, copper Cu, and gold Au. In this embodiment, the wiring layer 12 is made of a simple substance of copper Cu.

A manufacturing process of the circuit board 1 having the above-described structure will be described with reference to FIGS. 1 and 2.

(1) Manufacturing process of the first wiring layer 3 First, molybdenum-copper is formed on the insulating substrate 2 shown in FIG. 1 by a sputtering method. This is molybdenum with a thickness of 0.2
μm and copper to a film thickness of 0.4 μm by the same batch continuous sputtering. Subsequently, copper electroplating is performed to a film thickness of 3 μm. Subsequently, chromium is formed to a film thickness of 0.1 μm by sputtering.

(2) Processing Step of First Wiring Layer 3 A so-called negative resist is applied on the multilayer metal thin film obtained as described above by a spinner method. In the spinner method, the insulating substrate 2 on which the multilayer metal thin film is formed is
The resist is adsorbed and fixed on a predetermined stage, the liquid resist is dropped, and then this stage is rotated at 1000 rpm for 10 seconds. Due to the centrifugal force at this time, the liquid resist is uniformly diffused outward in the radial direction, and the resist can be applied to the metal thin film with a uniform film thickness. At this time, what is applied is a so-called resist precursor, and it is necessary to vaporize the solvent from this precursor. Therefore, for example, heating at 80 ° C. for 40 minutes in the air atmosphere, so-called pre-baking treatment is performed to semi-dry the liquid resist.

Next, in order to form a predetermined wiring pattern, a mask on which a predetermined wiring pattern is drawn is brought into close contact with the resist, and light is irradiated to expose the resist layer. By such a so-called contact exposure, a resist pattern having the dimensions of the mast can be obtained. A so-called post-baking process is performed in order to develop the structure including the exposed resist layer by, for example, a xylene-based developer, and then to make the resist material have a structure resistant to the etching process described later. That is, heating is performed at 130 ° C. for 30 minutes in the air atmosphere to thermally crosslink the resist material to form a strong film. Further, this improves the adhesion to the underlying multi-layer metal thin film layer.

Next, etching of the chromium layer having the above-described structure is performed by immersing the substrate on which the metal thin film layer and the resist layer are formed in 30% hydrochloric acid. Next, the copper layer below the chromium layer is etched. This is done by immersion in an aqueous solution of ammonium persulfate, followed by etching of the molybdenum layer. This is done by immersion in an aqueous potassium ferricyanide solution. After the metal thin film layer is completely etched in this manner, the resist layer is immersed in a stripping solution at 80 ° C. for 20 minutes to strip it. The stripping solution used here is of a commercially available type.

(3) Insulating Layer (Polyimide Resin Layer 7) Film Forming Step A polyimide precursor having a composition described below is applied onto the circuit board 1 after the etching step. This is done, for example, by the spinner method as described above, which rotates the stays, for example at 2000 rpm for 10 seconds. As a result, the polyimide precursor is applied with a uniform film thickness. Subsequently, heating is performed at 80 ° C. for 40 minutes in the air atmosphere to vaporize the solvent from the polyimide precursor and semi-dry it.

Subsequently, a curing process is performed on the semi-dried polyimide precursor. This is because the molecules of the precursor are imidized by heating the polyimide precursor to form a desired polyimide structure. The processing conditions are
For example, using a conveyor type continuous furnace, heating is performed at 400 ° C. for a maximum of 1 hour in a nitrogen gas atmosphere. This gives the polyimide precursor the desired polyimide structure and a film thickness of 10 μm.
m of the insulating film (polyimide resin layer 7) is obtained.

(4) Processing Step of Insulating Layer (Polyimide Resin Layer 7) This step is a processing step of forming the through holes 5 of the polyimide resin layer 4 as shown in FIG. Silicon oxide SiO ₂ is deposited on the polyimide film after the curing treatment.
Sputtering is performed so as to have a film thickness of μm. Subsequently, a positive resist is applied by the spinner method (1200 rpm, rotation for 10 seconds), and heated in an air atmosphere at 85 ° C. for 90 minutes to semi-dry the entire resist. Next, the contact exposure described above is performed to form a pattern for forming a predetermined through hole 5 and the like, and development is performed with an alkaline developing solution. Then, heat treatment (post-baking treatment) is performed at 135 ° C. for 30 minutes in the air atmosphere to thermally crosslink the resist material.

After that, the silicon oxide is etched by immersing it in an aqueous solution of ammonium hydrogen fluoride. Subsequently, in order to peel off the resist layer, it is immersed in a commercially available stripping solution at 60 ° C. for 20 minutes. Then, the polyimide resin layer 4 is etched according to the pattern of silicon oxide. This is done using a reactive ion etching system. Next, the silicon oxide that has been the mask layer for etching the polyimide resin layer is removed. This is done by immersing in the aqueous solution of ammonium hydrogen fluoride.

(5) Film forming process of second wiring layer 6 This is the same as the film forming process of the first wiring layer 3 shown in the above (I)-(1), and hereinafter, the processes of the first to fourth items. By repeating the process, the multilayer printed circuit board 1 can be manufactured.

(II) Manufacturing Process of Polyimide Precursor A manufacturing method of the polyimide precursor used in the manufacturing process of the circuit board 1 described in the above (I) will be described.

Weigh 700 g of N-methyl-2-pyrrolidone solvent into 2 flasks. Add 5 g of 2,5 diaminonitrobenzene to this.
Add the solvent with stirring at 0 ° C. and dissolve completely. 2, 5
After the diaminonitrobenzene has completely dissolved, 124 g of pyromellitic dianhydride are added to the solution in small portions with stirring. Let it react for 30 minutes in this state. Then, the system temperature is raised to 80 ° C. and the reaction is continued for 30 minutes. The inside of this reaction system is a nitrogen gas atmosphere. The polyamidecarboxylic acid thus obtained is used as a polyimide precursor.

It has been confirmed by the present inventors that the polyimide resin layers 4 and 7 produced using such a polyimide precursor have the characteristics shown in Table 1 below.

(III) Reasons for limiting the film thickness of the polyimide resin layers 4, 7 and the wiring layers 3, 6, 9 (1) Regarding the polyimide resin layers 4, 7 (a) When the film thickness of the polyimide resin layers 4, 7 is 2 μm or less There is a risk that a short circuit may occur between the wiring layers 3, 6 and 9 above and below the pinholes generated in the polyimide resin layers 4 and 7.

When the circuit board 1 shown in FIG. 1 has a multi-layer structure, it is possible to flatten the unevenness due to the pattern formation of the wiring layer on the side of the insulating substrate 2 of a certain polyimide resin layer and the through holes of the similar polyimide resin layer. Therefore, it becomes difficult to finely process the upper metal layer.

When the capacitance increases and a high frequency signal is used, it causes waveform distortion of the signal.

It becomes difficult to control the characteristic impedance. That is,
Characteristic impedance (30-15
It has been confirmed by the present inventor that a film thickness of the polyimide resin layer of 2 to 50 μm is necessary to suppress the thickness to 0 Ω).

(A) When the film thickness is 50 μm or more The volume stress of the polyimide resin layer increases, the adhesion of the polyimide resin layer decreases, and peeling occurs.

When the circuit board 1 has a multi-layer structure due to the thermal stress of the polyimide resin layer, stress is applied to the wiring layer in the through hole 8 as shown in FIG. 1, and in the configuration example of FIG. The reliability of electrical conduction between the layer 6 and the first wiring layer 3 is lost.

(2) Thickness of the adhesion layers 10 and 11 (see FIG. 2) (250 to 4000
Å) (a) In the case of 250 Å or less Adhesion layers 10 and 11 (molybdenum, chromium, titanium, tungsten, etc.) and wiring layers 12 (copper, aluminum, gold, etc.)
Are diffused into each other due to heat, and due to the Kirkendall effect, the wiring layer 12 comes into contact with the insulating substrate 2 or the polyimide resin layers 4 and 7 which is the underlying layer, and the adhesion strength is deteriorated.

(B) When the film thickness is 4000 Å or more The residual stress (tensile stress) of the adhesion layers 10 and 11 becomes large, and the stress is concentrated in the corners of the wiring layers 3, 6 and 9 formed in a predetermined pattern. Cracks occur in the polyimide resin layer that is the base.

(3) Regarding the film thickness of the wiring layer 12 of 0.5 to 15 μm (a) When the film thickness is 0.5 μm or less Since the electric resistance value is inversely proportional to the cross-sectional area, in this case, the electric resistance value unnecessarily increases and the circuit board It cannot be used as 1.

(B) When the film thickness is 15 μm or more, the residual stress of the wiring layers 4, 6 and 9 formed including the wiring layer 12 becomes large, and cracks occur in the polyimide resin layers 4 and 7 as the base. .

When the wiring layer 12 is processed (etched), if the film thickness is large, the degree of etching in the width direction is undesirably increased, which makes fine wiring processing difficult.

(IV) Adhesion Strength Experiment Method The present invention uses the circuit board 1 described with reference to FIGS. 1 and 2 as one embodiment thereof, and the object of the present invention is, for example, the first embodiment. Polyimide resin layer in the figure
The adhesion strength between the wiring layers 4, 7 and the wiring layers 3, 6, 9 above and below it is improved. Therefore, a test piece 13 as shown in FIG. 3 is prepared, and the polyimide resin layer 14 and the metal layer 15 are formed. The adhesion strength with was measured.

(1) Method for producing test piece 13 Film-forming step of polyimide resin layer 14 The polyimide precursor described in the manufacturing step in the above (II) section is applied onto an insulating substrate 16 made of, for example, a ceramic material,
Apply by the spinner method described above (2000 rpm for 10 seconds).
Next, heating at 80 ° C for 40 minutes in air (prebaking)
Then, the polyimide precursor is semi-dried. After that, the above-mentioned curing process is performed. That is, using a conveyor type continuous furnace, heating is carried out at 400 ° C. for a maximum of 1 hour in a nitrogen gas atmosphere, and thermal crosslinking is carried out to form a polyimide resin layer 14 having a film thickness of 10 μm.

Film-forming step of metal layer 15 Molybdenum is formed to a thickness of 0.2 μm and copper is formed to a thickness of 0.4 μm on the polyimide resin layer 14 by a sputtering method. Copper is formed thereon by electrolytic plating to a film thickness of 3 μm.

Processing Step of Metal Layer 15 A negative resist precursor is applied on the metal layer 15 by a spinner method (1000 rpm for 10 seconds). Thereafter, heating (prebaking) is performed at 80 ° C. for 40 minutes in the air atmosphere, and the above-mentioned contact exposure is performed using a 1 μm ² dot pattern mask. After that, development is performed using a xylene-based developing solution, and heating (post-baking) is performed at 30 ° C. for 30 minutes in the air atmosphere to thermally crosslink the resist.

Copper etching is performed on the resist on which the desired circuit wiring pattern is printed. This is done by immersing in an ammonium persulfate aqueous solution,
The molybdenum layer is etched by immersing it in an aqueous potassium ferricyanide solution. After that, in order to peel off the resist layer, use a normal commercial stripper (80 ℃).
Soak for 20 minutes.

Solder dipping process Dipping is performed by immersing in molten solder (Pb: Sn = 60: 40, 250 ° C) for 5 seconds.

Measurement method A copper wire having a diameter of 1.5 μm is vertically soldered to the metal layer 15 of 1 mm ² described above. Next, after fixing the insulating substrate 16, the copper wire is pulled up vertically in the direction opposite to the insulating substrate 16. In this way, the load applied to the copper wire when the metal layer 15 is peeled off is taken as the adhesion strength.

(V) Measurement result Using a polyimide resin represented by the general formula, a high temperature storage test is performed in an air atmosphere at 150 ° C. At this time, the following third
As shown in the table, the test and the adhesion strength as described in the item of "(V) Measuring method" are performed at each elapsed time. At this time, the functional groups R1 and R2 used in the polyimide resin used according to the present invention and the conventional polyimide resin used as a comparative example are the following second groups.
It is as shown in the table.

The results of the adhesion strength test as described above for various combinations of the functional groups R1 and R2 are shown in Table 3 below.

The symbol "-" in the column of polyimide structure in Table 3 is
Each functional group which is an electron donating group of the prior art shown in Table 2 is used in an arbitrary combination.

As described above, in the circuit board 1 of this embodiment, the adhesion strength between the polyimide resin layers 4, 7 and the wiring layers 3, 6, 9 is improved,
Moreover, the reliability of the adhesion strength is improved even in a hot environment, so that the life of the multilayer printed circuit board 1 can be remarkably extended.

As described above, since the polyimide resin layers 4 and 7 and the wiring layers 3, 6 and 9 realize a stable chemical bond with each other, in the photolithography process and the polyimide curing process in the manufacturing process of multilayer wiring. The adhesion strength is prevented from deteriorating even during heat treatment, and the peeling of the wiring layers 3, 6, 9 during the manufacturing process is prevented.

It is possible to prevent such a situation that a defective connection occurs in the through hole portion of the polyimide resin layer 4 as described above. Further, the deterioration of the adhesion strength of the metal film can be prevented in the heat treatment process for chip attachment of the integrated circuit using the circuit board 1 of this embodiment.

It is possible to prevent the deterioration of the metal film adhesion strength of the die bonding portion, the wire bonding pad and the solder bump portion in the integrated circuit element described above.

In addition, the bond between the polyimide resin and the metal is stable and the reliability after that is significantly improved even by the thermal process when mounting an electronic circuit or the like on the circuit board 1.

FIG. 4 is a plan view of an integrated circuit device 17 according to another embodiment of the present invention, and FIG. 5 is a sectional view taken along the section line VV of FIG. This embodiment will be described with reference to FIGS. 4 and 5. A polyimide resin layer 20, a wiring layer 21, and a polyimide resin layer 22 are formed on an insulating substrate 19 made of a ceramic material or the like through the same steps as the manufacturing steps of the first embodiment described above. In the package 18 including the insulating substrate 19, the polyimide resin layers 20, 22 and the wiring layer 21, the integrated circuit element 17 of the uppermost polyimide resin layer 22 is formed.
The peripheral portion on the side is peeled and removed as shown in FIG. 5, and the integrated circuit element 17 and the wiring layer 21 are wire-bonded, for example.

As described above, in the manufacturing process of the package 18 for storing the integrated circuit element 17, various kinds of heat atmosphere are used, and by adopting the manufacturing process shown in the first embodiment, the package 18 is processed. Also, the same effect as the effect described in the above-described embodiment can be realized.

As described above, according to the present invention, the adhesion strength between the polyimide resin layer and the metal thin film formed on the surface of the polyimide resin layer is significantly improved, and the reliability of the adhesion strength is improved even in a thermal environment. , Which is much higher than the conventional technology. Therefore, even under various heat treatment processes in the process of manufacturing electronic circuit parts or under heat generation condition processing steps in using the electronic circuit parts as products, the metal thin film realized as circuit wiring or the like is a polyimide resin layer. It is possible to improve the quality and reliability significantly without peeling off.

[Brief description of drawings]

FIG. 1 is a sectional view of a circuit board 1 according to an embodiment of the present invention, and FIG.
FIG. 4 is a sectional view of the vicinity of the second wiring layer 6, FIG. 3 is a sectional view of a test piece 13 for measuring adhesion strength, and FIG. 4 is a package 18 of an integrated circuit element 17 used as another embodiment of the present invention. A simplified plan view and FIG. 5 are sectional views taken along the section line V-V in FIG. 1 ... Circuit board, 2,16 ... insulation board, 3 ... first wiring layer, 4,7,14,20,22 ... polyimide resin layer, 5,8 ... through hole, 6 ... second Wiring layer, 9 ... Third wiring layer, 10,1
1 ... contact layer, 12 ... wiring layer, 17 ... integrated circuit element, 18
……package

Claims (7)

[Claims] 1. An electronic circuit component comprising a polyimide resin formed on a surface of a base material and a metal thin film formed on the polyimide resin, wherein the polyimide resin is of the general formula: The electronic circuit component is characterized in that the type represented by is selected, and at least one of the functional groups R1 and R2 is an electron-withdrawing group. 2. The electron-withdrawing group is represented by the general formula: The electronic circuit component according to claim 1, wherein the electronic circuit component is selected from the types represented by. 3. A surface of the metal thin film which is in contact with at least a polyimide resin is molybdenum (Mo), chromium (Cr),
The electronic circuit component according to claim 1, wherein the electronic circuit component is made of at least one element selected from titanium (Ti) and tungsten (W), or an alloy of two or more of these elements. 4. The electronic circuit component according to claim 1, wherein at least one of ceramics, glass and metal is selected as the base material. 5. The electronic circuit component according to claim 1, wherein the polyimide resin layer is formed to have a layer thickness of 2 to 50 μm. 6. The electronic circuit component according to claim 1 or 3, wherein the metal thin film is formed to have a film thickness of 250 to 4000Å. 7. A portion of the metal thin film which is not in contact with the polyimide resin layer is made of at least one of aluminum (Al), copper (Cu) and gold (Au). And the electronic circuit component according to item 3.