JPH0453293A - Forming method for insulating film - Google Patents

Abstract

PURPOSE:To prevent pinholes induced in an insulating film from reaching a conductive layer as they communicate with each other by a method wherein odd-numbered and even-numbered insulating layers forming the insulating film are exposed to light using different light exposure masks respectively. CONSTITUTION:A first light exposure mask 5-1 and a second light exposure mask 5-2 are used at light exposure, and in an insulating film 4, an insulating layer 3-1 as an odd-numbered layer is exposed to light through the first light exposure mask 5-1, and an insulating layer 3-2 as an even-numbered layer is exposed to light through the second light exposure mask 5-2. As mentioned above, an even-numbered layer and an odd-numbered layer are made to use different light exposure masks, so that pinholes of the layers induced by the flaws of the light exposure masks are prevented from being coincident with each other in position. Therefore, pinholes are prevented from communicating with each other to make a conductive layer 2 exposed, so that the layer 2 is surely covered with the insulating film 4 and a product can be improved in quality.

Description

[Detailed Description of the Invention] [Summary] Regarding an insulating film forming method in which an insulating film of a predetermined thickness is formed by laminating a plurality of insulating layers, pin poles generated in the insulating film reach a conductive layer by communicating with each other. For the purpose of preventing this, a plurality of first and second exposure masks are used during exposure, and the first exposure mask is used to expose the insulating layers that are the odd-numbered layers in the insulating film. The structure is such that the even-numbered insulating layers are exposed to light using a second exposure mask.

(Industrial Application Field) The present invention relates to an insulating film forming method for forming an insulating film of a predetermined thickness by laminating a plurality of insulating layers.

Ceramic substrates on which circuit networks are formed are used in electronic devices, such as boat fishing, in which a conductive layer is formed on the surface of the ceramic substrate, and an insulating film is formed to cover the conductive layer.

Such an insulating film is coated with photosensitive polyimide and exposed in 4-1.
They are laminated by developing.

However, there is a limit to the thickness of the insulating film that can be formed by one-time coating, exposure and development of photosensitive polyimide.

Therefore, when it is desired to increase the thickness of the insulating film due to the electrical property Q of the conductive layer, the thickness can be increased by repeating coating, exposing, and developing the photosensitive polyimide several times.

[Prior Art] Conventionally, manufacturing has been carried out according to the steps shown in the conventional manufacturing process diagrams of <a> to (f) in FIG. 3.

As shown in FIG. 3(a), first, photosensitive polyimide is applied to the surface IA of the substrate 1 made of ceramic,
A coating film 10 having a thickness T is formed so as to cover the conductive layer 2 disposed directly on the surface.

After the coating film 10 is cured, it is exposed to light by overlapping exposure masks as shown in (1), and unnecessary parts of the coating film 10 are removed by development, and as shown in (C), the thickness T An insulating layer 3-1 is formed.

Next, as shown in (d), photosensitive polyimide is coated on the upper layer of the insulating layer 3-1 to form a coating film of 17 T, and after the coating film 11 is cured, as shown in (e). In the same way as described above, the exposure mask is overlapped and exposed, and unnecessary parts of the coating film 11 are removed by development. 2. As shown in (f), the L layer of the insulating layer 3-1 is By laminating the insulating layer 3-2, the thickness f
, the insulating film 4 was formed.

Usually, a coating film is formed by applying this type of photosensitive polyimide once.1. The thickness of O,1,I is approximately 10μ
Therefore, a thick insulating film 4 has been formed by stacking the insulating layers 31 and 3-2 so that the thickness t of the insulating film 4 is about 20 μm.

Therefore, if you want to further increase the thickness t of the insulating film 4, repeat coating of photosensitive polyimide and exposure and development. The insulating film 4 is now formed.

[Problems to be Solved by the Invention] However, by repeatedly applying photosensitive polyimide, exposing and developing a plurality of insulating layers 3-1 and 3-2, the insulating film 4 can be formed. By increasing the thickness, for example, if there are "scratches" on the exposure mask 5 used during exposure,
For example, in the case of a negative type, the unexposed areas are
In the case of a positive type, the area that should be exposed is not exposed due to the 1-1-z. A pinball like the one shown in part 4 of (f) of the inning occurs.

Furthermore, by using one exposure mask 5, pinballs occur at the same location, and the pinballs communicate with the insulating layers 3-1 and 3-2.

Therefore, insulation with respect to the conductive layer 2 is no longer performed,
Furthermore, there were other problems such as penetration of the treatment liquid in the ethoching process.

Therefore, an object of the present invention is to prevent the pinballs generated in the insulating film from reaching the conductive layer by communicating with each other.

[Failure to solve the problem]

FIGS. 1(a) and 1(b) are diagrams explaining the principle of the present invention.

As shown in FIGS. 1(a) and 1(b), during exposure, a plurality of first and second exposure masks 5-1 and 5-2 are used to cover the odd-numbered layers of the insulating film 4. The first exposure mask 5-1 is used to expose the insulating layer 3-1, and the second exposure mask 5 is used to expose the even-numbered insulating layer 3-2.
-2 is composed of go, yo, and so.

With this configuration, the above-mentioned problem is solved.

[Effect]

That is, exposure of the odd-numbered insulating layers constituting the insulating film is performed by using the first exposure mask, and exposure of the even-numbered layers is performed by using the second exposure mask, and the odd-numbered layers and even-numbered layers are By using different exposure masks, it is possible to avoid misalignment of pinball positions caused by "kissing" of each exposure mask.

Therefore, as described above, the conductive layer 2 is not exposed due to the pinholes communicating with each other, and the conductive layer 2 can be reliably covered by the insulating film 4Q, thereby improving quality.

〔Example] The present invention will be explained in detail below with reference to FIG.

FIG. 2 is an explanatory diagram of an embodiment according to the present invention.
(a6) is a manufacturing process diagram, and (b) is a side sectional view. All figures are 1ff), and the same/signs indicate the same/objects.

As shown in FIG. 2(al), the surface 1 of the substrate 1 is coated with a -C conductive layer 2 by coating photosensitive polyimide.
8) Form a coating film 10 of V and T, and expose the coating film 10 with a first exposure mask 5-1 as shown in (a2),
After development, the insulating layer 3-1 shown in (a3) is laminated.
cormorant.

Next, on the - layer of the insulating layer 3-1, a coating film 11 with a strength of 1 is formed by applying a photosensitive polyimide as shown in (a4), This time, as shown in (a5), the second
The coating film 11 is exposed to light using the exposure mask 5-2, and after the exposure, the insulation layer 3-2 is laminated on the -L layer of the insulation layer 31 by development as shown in (a6). )
This is how the pattern 4 is formed.

Therefore, as shown in (b), the first exposure mask 5-1
If there is a "scratch" on the insulating layer 3-1, the scratches shown in A will occur on the insulating layer 3-1, and the second exposure mask 5
If there is [-1 yuzu-1 in -2, the bottle ball shown in 8 will occur in the insulating layer 3-2.

In this case, the positions of the first exposure mask 5- and the second exposure mask 5-2 will not necessarily match if there is any scratch.

Therefore, there is a shift in the location where the pinhole occurs, and the pinhole generated in the insulating layer 31 as described above and
There is no communication with the pinballs generated in the insulating layer 3-2, and the conductive layer 2 is never exposed.

Note that even in the case where the insulation layer 4 is formed by a large number of insulation layers such as three or four layers by laminating another insulation layer on top of the insulation layer 32, the exposure of the odd-numbered layers is performed first.
A similar effect can be obtained by using different exposure masks for the odd and even layers, such that the exposure of the even layers is performed using the second exposure mask 5-2.

〔Effect of the invention〕

As explained above, according to the present invention, the exposure of the insulating layer constituting the insulating film is performed by using different exposure masks for the odd-numbered fine thread A layer and the even-numbered insulating layer. By making sure that the positions of the pinholes created by the kiss J in the exposure mask do not coincide in each insulating layer, it is possible to prevent pinballs from having a negative effect on the conductive layer.

Therefore, the position of the pinball as in the past is communicated with each insulating layer, and there is no negative effect on the conductive layer, improving the quality and improving the practical effect. It is.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) are diagrams explaining the principle of the present invention. FIG. 2 is an explanatory diagram of an embodiment according to the present invention, (81) to
(a6) is a manufacturing process diagram, (b) is a side sectional view (
a) to <f) show conventional manufacturing process diagrams. In the figure, 2 is a substrate, 2 is a conductive layer 3-1. ．． 3-
2 is an insulating layer; 4 is an insulating film; 5-2 is a first exposure mask; and 5-2 is a second exposure mask. 11 娑朕(a)(C) Conventional child manufacturer

Claims (1)

[Claims] By repeating coating, exposing and developing photosensitive polyimide, the substrate (
A predetermined film thickness (
t) insulating film forming method for forming the insulating film (4), wherein during the exposure, a plurality of first and second exposure masks (
5-1, 5-2), the insulating layer (3-1) which is the odd layer in the insulating film (4) is exposed to light using the first exposure mask (5-1), and the even layer and An insulating layer (
3-2) is exposed using a second exposure mask (5-2).