JPS5812392A - Flattened wire - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a planarized wiring, and more specifically, to a planarized wiring in which a conductive layer is formed of a polymer resin film.

Conventionally, wiring has generally been formed by vapor depositing copper or aluminum and etching it into the wiring shape. For example, as shown in FIG. 1, in order to form wiring on a resin substrate, substrate forming step 1. Metal deposition process 2, wiring mask formation process for metal etching 3. Etching process of metal layer 4. A wiring mask removal step 5 is required. Therefore, the cost of manufacturing Rikishima et al. was also high due to the large number of steps. In addition, there is a difference in level between the wiring and the board, and when a so-called multilayer wiring is formed in which multiple conductive layers are stacked with insulating layers interposed therebetween, disconnection may occur.

An object of the present invention is to provide a planarized wiring that does not have the above-mentioned drawbacks, is easy to manufacture, and has good electrical characteristics.

The structure of the present invention for achieving the above object is to provide an insulating substrate made of a polymer resin with a conductive polymer resin film made conductive by selective laser beam irradiation.

Polymer resins such as polyimide, polyacrylonitrile, polyacrylic toimide, phenol resin, polyphenylene, polyphenylene sulfide, and polyacetylene have low conductivity in their normal state and are used as insulators. When these polymer resins are irradiated with a CW laser beam of COI gas, the irradiated portions change from polyimide to low molecules (for example, Hlo).

Co, co! ), and the polymer in the irradiated area became a conductor. The conductivity can be set to a desired value depending on the laser beam intensity, scanning speed, etc., but it is easy to obtain a conductivity up to a maximum of about 101Ω゛1・cW1′″1, which is used for ordinary conductor wiring. The conductivity can also be adjusted by the position of the focal point of the laser beam, but when focusing on the surface part, the conductive area has a width of 40 am and a depth of 40 am. 5
~10 μm, which is suitable.

The above-mentioned polymer resin is prepared in advance by i, ＃B'le''
Halogen molecules such as 4, Lewis acids such as A8F, etc.

It is even better to use a material doped with a protonic acid such as 1-6so, or an alkali metal such as Ll, Na, or K, since the conductivity is further improved by light irradiation.

The doping amount is usually 10-1 to 0.5 mol % (mol % based on unit monomer).

Further, it is even better if the polymer resin is one in which fine metal particles such as Ag1Cu are dispersed in advance. In this case, it goes without saying that the polymer resin should be dispersed to the extent that it does not lose its insulation properties.

Hereinafter, it will be explained in detail using examples.

FIG. 2 is a schematic perspective view of an electric element using planarized wiring as an embodiment of the present invention.

In the figure, a polyimide sheet 22 with a negative side of 1 and a film thickness of 50 μm is provided on a ceramic substrate 21. When the sheet 22 is scanned in a predetermined pattern by narrowing the CO or gas laser beam to a spot diameter of 40 pm, the irradiated portion 24 becomes a conductive area. This conductive area 2
The electrical conductivity of 4 is 10"ρ-1o11°1. The conductive region 24 can also be used as a resistor by being partitioned into an insulating region 23. A 9-wire 25 is connected to the end of the resistor. are connected to form an electric element.

As described above, in the present invention, as shown in the partial process diagram of FIG. 3, a substrate or a part of the substrate is formed 31 using an insulating polymer, and a region where wiring is to be formed is irradiated 32 with laser light. Only the area irradiated with laser light becomes conductive, allowing wiring to be formed with fewer steps.

FIG. 4 is a schematic cross-sectional view of an electric element using flattened wiring as another embodiment of the present invention. In FIG. 5iQ on the crystal 41 and a part of the diffusion region 42.
A film 43 is formed on the film 43 and the diffusion region 4.
A thin film 44 is formed on A/2. The above At thin film 44 and the above 8i0. A polyimide thin film 451 having a thickness of 1 to 50 μm is formed on the film 43. This thin film is made by coating method,
A known forming method such as a dipping method may be used. After this thin film is solidified, a portion of the polyimide thin film 45 on the At thin film 44 is made conductive by irradiating laser light using a mask (not shown) with a predetermined pattern.

Since a portion of the resin layer 451 is made conductive by light irradiation, the height of the insulating portion 451 and the height of the conductor layer 45 are at the same level, and a flat surface is formed. In the figure, the underlying At layer 44 and the conductor layer 45 are electrically connected, but when used as a wiring layer (not shown) such as a crossover wiring, they are provided independently in the resin layer 451.

The application, solidification, and light irradiation of the polyimide solution are then repeated in sequence in the same manner as described above to form an electrical device having an integrated circuit with a multilayer wiring structure. The wiring can also be formed by covering the area other than the wiring formation area with about 1000 O7 aluminum and irradiating the entire surface with laser light.

The invention is capable of further improvements. When the above polyimide thin film] 51 is doped with AIIP, etc., the conductivity increases to 3.
This was an improvement of more than an order of magnitude compared to the previous year. This dope, for example, is applied to AIF at room temperature at a pressure of 10-10 to 1'porr.
, by leaving it in a gas for 1 hour to several days. Similar effects were obtained by using polyacrylonitrile, boriaodoimide, phenol resin, polyphenylene, polyphenylene sulfide, and polyacetylene in place of the above-mentioned polyimide. In addition, ■! as the above doping agent! ,BrI,Ct*7! : Tonohalogen molecule, H
! So.

Lewis acids such as boutonic acid, AIF, etc.
Alkali metals such as LltNa and x can be similarly applied without any difference, and the same effects were obtained.The present invention can also be improved as follows. Example, tba~
When forming a polyimide sheet, it is best to disperse a small amount of metal (AgeC''* etc.) fine particles to the extent that the sheet does not lose its insulating properties.In this case, the conductivity of one wiring section will further improve. .

In the above-mentioned embodiment, a cobalt gas laser was used as the laser beam, but other gas lasers and solid-state lasers may be used.

Even if a semiconductor laser was used, it could be applied in exactly the same way.

It may be selected as appropriate based on the wavelength of these laser beams and the absorption coefficient of the polymer.

As described above, the present invention is capable of providing flattened wiring by converting the light-irradiated portion of an insulating polymer resin film into conductive, and is extremely easy to manufacture and has excellent electrical characteristics. It is of good quality and has great industrial benefits.

[Brief explanation of the drawing]

Fig. 1 is a schematic process diagram of a conventional manufacturing method, Fig. 2 is a schematic perspective view of an electric element using flattened wiring as an embodiment of the present invention, and Fig. 3 is a partial process diagram used in Fig. 2. , FIG. 4 is a schematic cross-sectional view of an electric element using planarized wiring as another embodiment of the present invention. 21... Ceramic substrate, 22... Polyimide thin film, 23... Polyimide thin film (insulating part), 24...
Poly'￥J 1 troublefJ 2 Figure'l! i3 Figure% 4 Figure

Claims (1)

[Claims] 1. In a flattened wiring formed on a substrate and having a flat surface and conductive layers arranged at approximately the same height, the conductive layer is made of an insulating polymer that is irradiated with light to become a conductor. 1. A flattened wiring characterized by being a polymer resin film. 2. In claim 1, the polymer resin is polyimide or polyacrylonitrile. Boria construction toy construction, phenolic resin, polyphenylene,
A flattened wiring characterized by using at least one of polyphenylene sulfite and polyacetylene. λ In claim 1, the planarized wiring is characterized in that the polymer resin film is doped with at least one of a half-fluoride molecule, a Lewis acid, a protonic acid, and an alkali metal. . 4. The planarized wiring according to claim 1, wherein the polymer resin film is formed by dispersing fine metal particles.