JPH03150894A - Managing method for film thickness of multilayer thin film circuit board - Google Patents

Abstract

PURPOSE:To sufficiently manage the thickness of an insulating film by forming a film thickness checking hole simultaneously when viaholes for connecting between wiring films are formed at the film, and knowing the thickness of the film formed by measuring the depth. CONSTITUTION:Photosensitive organic insulating films 1b and a wiring film 1c are alternately laminated on a power source board 1a. When the films 1b and 1c are alternately laminated, viaholes 1bc for electrically connecting the film 1b to the film 1c are formed, and a film thickness checking hole 1d is simultaneously formed. The depth of the hole 1d, i.e., the thickness of the film 1b is measured in contact with the contact stylus, etc., of a film thickness measuring unit. If the thickness is improper, the improper film 1b is peeled at this time, and the film is reformed. Thus, the thickness of the film 1b can accurately by managed and formed.

Description

[Detailed Description of the Invention] [Summary] Regarding a method for controlling the film thickness of a multilayer thin film circuit board, a photosensitive organic insulating film and a wiring film are formed on the board with the aim of sufficiently controlling the film thickness of the insulating film. In the process of manufacturing a multilayer thin film circuit board formed by alternately laminating layers, a film thickness check hole is formed at the same time as a via hole connecting the wiring films is formed in the insulating film, and the film thickness check hole is The depth is measured, and if the film thickness is normal, the process proceeds to the next step of forming a wiring film, and if it is defective, it is peeled off and the process returns to the insulating film forming process to perform lamination.

[Industrial application field]

The present invention relates to a method for controlling the thickness of an insulating film on a multilayer thin film circuit board.

With the recent progress in semiconductor technology, high-performance circuit boards for mounting semiconductor devices are required in order to fully exploit the characteristics of highly integrated and high-speed semiconductor devices. Photolithography technology for photosensitive dielectric constant and wiring film (sensor pattern) [coating of photosensitive organic insulating material → pre-bake (drying) → exposure → development → post-bake (drying)...] A multi-N thin film circuit board formed by alternately laminating layers has been put into practical use.

Via holes are formed in the insulating film to electrically connect between the wiring legs, but since the thickness of the insulating film affects the electrical characteristics (characteristic impedance) of the circuit board, it is desired that the film be formed to a constant thickness. ing.

[Conventional technology]

FIG. 3 shows a sectional side view of a main part of a circuit board for mounting a semiconductor device manufactured by a conventional method.

As shown in the figure, a substrate made of an inorganic material such as alumina or glass ceramic is connected to several types of power supply wiring films 11a-3.
The power supply wiring film 11a-3 of each layer is stacked in multiple layers with the
is the land 1la- on the surface via the via hole 1la-2.
On the power supply board 11a connected to 1, a photosensitive organic insulating film 11b and a wiring film (conductor pattern) 11c are alternately laminated by photolithography to form a multilayer circuit board for mounting a desired semiconductor device. 11 are manufactured.

Via holes 11bc for electrically connecting the wiring films 11c are formed in predetermined positions in the insulating film 11b by applying a photosensitive organic insulating material - pre-hake (drying) -> exposure -> development -> post-bake (drying). The film thickness is controlled by regulating the number of rotations of the spin coater in advance in the coating process using a spin coater (the path shown in the figure) using the spin code method.

[Problem to be solved by the invention]

However, according to this method of controlling the thickness of the insulating film, there is a problem that the thickness of the insulating film decreases during the development process, and when the insulating film and wiring film are multilayered, the thickness of the insulating film decreases. There was a problem in that variations in thickness had a large effect on the electrical characteristics (characteristic impedance) of the circuit board.

In view of the above-mentioned problems, an object of the present invention is to provide a method for controlling the thickness of an insulating film of a multilayer thin film circuit board by which the thickness of the insulating film can be sufficiently controlled.

[Means to solve the problem]

In order to achieve the above object, in the method of controlling the insulation film thickness of a multilayer thin film circuit board of the present invention, when forming via holes connecting wiring films in a photosensitive organic insulation film, a film thickness check is simultaneously performed. A hole is formed, and the depth of the film thickness check hole is measured. If the film thickness is normal, proceed to the next process of wiring film formation. If it is defective, peel it off and return to the insulating film formation process again to continue lamination. Configure it to do so.

[Effect]

By forming a film thickness check hole at the same time as forming a via hole to connect wiring films in an insulating film, it is possible to measure the depth of the film thickness check hole and know the thickness of the formed insulating film. can.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The gist of the present invention will be explained in detail below based on an embodiment of manufacturing a multilayer circuit board for mounting a semiconductor device shown in the drawings.

FIG. 1 shows a side cross-sectional view of essential parts of a circuit board for mounting a semiconductor device according to an embodiment of the present invention.

As shown in the figure, the multilayer circuit board 1 for mounting semiconductor devices has several kinds of power supply wiring films 1a-3 in the inner layer, as in the conventional case, and ceramic and A photosensitive organic insulating film 1b and a wiring film (conductor pattern) 1c are alternately laminated on a substrate 1a made of an inorganic material such as glass ceramic, ie, a power supply board, by photolithography.

When the insulating films 1b and wiring films 1c are alternately laminated, via holes 1bc are formed in the insulating film 1b to electrically connect between the wiring films 1c as in the conventional method.
At the same time as forming bc, a film thickness check hole 1d is formed. That is, as shown in FIG. 2(a), (bl, (a side cross-sectional view showing the step-by-step process for forming the insulating film C1), in the insulating material coating process shown in FIG.
On the premise that the land 18-1 is formed (the figure omits the illustration of the power wiring film 1a-3 and the via hole 1a-2 shown in FIG. 1), a thick layer is formed on the land 18-1. Sa 40~
A photosensitive organic insulating material 1b' such as a polyimide resin that forms a 50 μm insulating film 1b is applied using a spin coater (as shown in the figure) using a spin code method, and pre-haked (dry at 80'C for 1 hour). )do.

Next, in the exposure and development process shown in FIG. 2B, the applied insulating material 1b' is exposed and developed using a glass mask (as shown) to form a via hole Ibc and a film thickness check hole 1d. The film thickness check hole 1d has a size of 1 cm to 21 squares, and is provided in the area outside the line film formation shown below, and is located in the area outside the line film formation, which is located above the insulating material 1b', that is, the film I of the insulating film 1b.
It is desirable to arrange them evenly at multiple locations (the figure shows one of them) so that 7 can be checked completely.

At this point, in the film thickness measurement process of diagram Te3,
The depth of the film thickness check hole 1d, that is, the thickness of the insulating film 1b, is measured by applying the stylus 2 of the film thickness measuring device.

(Please note that this is before post-baking, so a reduction in film thickness is expected.) If the film thickness is defective, the defective insulating film is removed at this point and the process is repeated from the insulating material coating step shown in Figure FA1.

If the film thickness is normal, perform the next boss bake (400℃,
A first layer insulating film 1b having via holes 1bc and film thickness check holes 1d is formed by drying for 2 to 3 hours.

Next, although not shown, the process moves to a second layer wiring film formation step, and after forming the wiring film, a third layer insulating film is formed in the same manner, and the insulating film and wiring film are sequentially laminated alternately to form the desired layer. A circuit board for mounting a semiconductor device is obtained.

In this way, by forming a film thickness check hole in the insulation film at the same time as forming a via hole, the film thickness can be directly measured. Compared to forming a film, the thickness of the insulating film is measured each time the insulating film is formed, so the film thickness can be controlled and formed accurately.

〔Effect of the invention〕

As described in detail above, according to the present invention, the thickness of the insulating film can be accurately controlled and formed, and it can be applied to, for example, the manufacture of circuit boards for mounting semiconductor devices to stabilize electrical properties, especially characteristic impedance. This has an extremely useful effect industrially, such as being able to provide semiconductor device modules and the like that are made of high-quality materials.

[Brief explanation of the drawing]

FIG. 1 shows i! according to the present invention! FIG. 2 is a side cross-sectional view of the main part of the fabricated circuit board for mounting a semiconductor device according to one embodiment (al, f).
bl and tel are side sectional views sequentially showing the insulating film forming process in FIG. 1, and FIG. 3 is a side sectional view of a main part of a circuit board for mounting a semiconductor device manufactured by a method according to the prior art. In the figure, 1 is a multilayer circuit board for mounting semiconductor devices, 1a is a substrate (power supply board), 1b is an insulating film, tb' is an insulating material, 1bc is a via hole, 1c is a wiring film (conductor bar), 1d is a The hole for checking film thickness is shown.゛・ki (Al insulation material coating process To) exposure and development process

Claims (1)

[Claims] In the step of manufacturing a multilayer thin film circuit board in which a photosensitive organic insulating film (1b) and a wiring film (1c) are alternately laminated on a substrate (1a), the insulating film (1b) ) When forming the via hole (1bc) connecting between the wiring films (1c), a film thickness check hole (1d) is formed at the same time, and the depth of the film thickness check hole (1d) is measured. If the film thickness is normal, proceed to the next step of forming the wiring film (1c), if it is defective, peel it off and repeat.
A method for controlling film thickness of a multilayer thin film circuit board, characterized by returning to the insulating film forming step and performing lamination.