JPS6160426B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a mask used in photoablation, which is a processing method for forming predetermined patterns, characters, grooves, etc. on a metal surface.

In photo ablation, the masks used in the normal process are mainly made of film with an emulsion layer.
Because the workpiece and emulsion layer are used in close contact with each other, they are easily scratched, and because they are based on plastic film, they are prone to distortion due to deformation, and pinholes are easily formed due to unevenness and peeling of the silver salt film. It has many drawbacks such as. For these reasons, film masks are unsuitable for mass production.

As a mask for photoablation that does not have the above disadvantages, a mask with a pattern of metal vapor deposited film on a glass plate, called a hard mask, is generally used, but it is expensive and has complicated and fine patterns. It is impossible to manufacture a three-dimensional mask.

Regarding three-dimensional photo-etching masks, there is a method of manufacturing photo-etching masks by electroforming as disclosed in Japanese Patent Application Laid-Open No. 131432/1983. In the case of this method, if the thickness of the plating layer is thick, the plating 3 will protrude onto the photoresist 2 as shown in FIG. etc., the accuracy of the contour becomes poor. However, if the thickness of the plating layer is reduced in order to prevent the above phenomenon, it becomes extremely difficult to peel it off from the model 1, which is made in the same shape as the workpiece, and even if it is peeled off, the plating layer is thin. Therefore, it is extremely difficult to maintain its shape without deforming it.

In the production of a photo-etching mask using the electroforming technology described above, the present invention adds relatively simple processing to the photo-etching mask without sacrificing the accuracy of the mask, and also improves the photo-etching of the workpiece. The object of the present invention is to provide a method for manufacturing a mask for photoablation that has sufficient strength to withstand mass production processing.

Next, embodiments of the present invention will be described with reference to the drawings. First, using a photoetching mask, a model 1 made of a conductive material or coated with a conductive film having the same shape as the workpiece to be photoetched is manufactured. The model 1 needs to have approximately the same size depending on the shape of the workpiece. The surface 11 of this model 1 is subjected to surface treatments such as cleaning and formation of an oxide film so that the plating in subsequent steps will not be uneven and the plating layer that will become a metal mask can be easily peeled off. Next, photoresist is applied to the surface 11 of the model 1, and when it dries, a first photomask 41, such as that used for normal exposure and phenomena, is placed over the model 1 coated with photoresist, and the photoresist is applied. conduct,
On the surface 11 of the model 1, a pattern to be processed into the workpiece,
Characters, grooves, etc. are formed using photoresist 21. Next, the photoresist 21 in model 1
A first plating layer 31 is formed by plating the surface portion where there is no plating. In this case, the first plating layer 3
If the thickness of the plating layer 31 is within the thickness of the photoresist 21, the same level of contour accuracy as the first photomask can be maintained, but if the thickness of the plating layer 31 exceeds the thickness of the photoresist 21, As mentioned above, a phenomenon peculiar to electroforming called upper deposit occurs as shown in FIG. 1, and as the thickness increases, the accuracy rapidly decreases. For this reason, in order to maintain accuracy, the thickness of the plating layer 31 needs to be equal to or less than the thickness of the photoresist 21. Photoresist 20 is again applied on the first plating layer 31 and the photoresist formed by this first plating operation as shown in FIG. 3, and dried. Next, exposure and phenomena are performed using a second photomask 42 having predetermined patterns, letters, grooves, etc. that are slightly smaller than the first photomask used initially. By using such a mask 42, a portion of the photoresist on the first plating layer 31 formed initially, which is slightly smaller than the area of the plating layer, is dissolved. Next, the photoresist is melted and the exposed first plating layer is plated again to form a second plating layer.

When this second plating layer 32 is completed, a photoresist is further applied on the second plating layer 32 and the photoresist 22, dried, and a desired pattern, which is the same as or smaller than the mask used for the second time, is formed.
Photo etching is carried out using a mask with letters, grooves, etc. Then, a third plating layer 33 is further formed on the exposed surface of the plating layer. By repeating the above steps as many times as necessary, multiple plating layers can be obtained, and in this example, there are three layers.

Next, as shown in FIG. 5, with the surface of the model 1 covered with the photoresist layer 25 and the multilayer plating layer, a low melting point metal, such as a solder melt with an appropriate viscosity, is applied to the upper layer of the multilayer plating layer. Apply. When this melted solder is cooled, a mask with high rigidity and strength is obtained in which the solder layer 5 is welded and solidified on the multilayer metal plating layer as shown in FIG.

In the above embodiments, the workpiece is a flat plate, and therefore the corresponding model is also a flat plate. However, the above method is suitable for manufacturing a mask for a workpiece that has a three-dimensional, complex shape. This can also be applied to

The mask manufacturing method of this invention is a low-cost method because it is relatively easy to apply a low melting point metal to multiple metal layers, and the manufactured mask has a multilayer metal layer with a thickness of at most 10 microns. The thickness of low melting point metals is several degrees, whereas the thickness of low melting point metals is several degrees.
The thickness is 100 microns, which is significantly greater than a mask made only of multilayer metal, resulting in significantly increased rigidity and strength, and excellent durability.

In addition, since the mask manufactured according to the present invention suppresses deformation due to internal stress in the multilayer metal layer caused by plating electroforming etc. with the low melting point metal layer, the deformation of the mask is small and the required patterns, letters, grooves, etc. are accurately formed. Therefore, by photo-etching a workpiece using this mask, a workpiece with highly accurate patterns, letters, grooves, etc. can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a part of the manufacturing process of a metal mask by conventional electroforming, FIGS. 2 to 6 are sectional views showing an embodiment of the present invention, and FIG. FIG. 3 is a cross-sectional view showing the preparation process for obtaining the second metal plating layer, and FIG. 4 shows that the second metal plating layer has been obtained. 5 is a cross-sectional view of a state in which a multilayer metal plating layer as a mask has been obtained, and FIG. 6 is a cross-sectional view of the multilayer metal plating layer described above,
FIG. 7 is a cross-sectional view showing a state in which the melted solder is further welded and solidified. Explanation of the symbols: 1 is a model, 20 is a photoresist, 2, 21, 22 is a photoresist after an exposure phenomenon, 3 is a plating layer, 31 is a first plating layer, 32
3 is the second plating layer, 33 is the third plating layer, and 5 is the solder layer.

Claims (1)

[Claims] 1 The surface of a conductive model with approximately the same dimensions and shape as the workpiece is subjected to surface treatments such as cleaning and formation of an anti-oxidation film to prevent uneven plating and ease of peeling off the plating layer. A film of photoresist is formed, and using a first photomask having required grooves, patterns, etc. prepared in advance, exposure and phenomenon are performed to form the required grooves, patterns, etc. by photoresist on the surface of the model. , Next, the surface portion is plated, and after the plating is completed, the plating layer is removed from the model to produce a metal mask having required grooves, patterns, etc. In the method, a plating layer for the metal mask is formed on the model surface portion. After that, with this plating layer still attached to the model, a second film of photoresist is formed on the photoresist and on the surface of the plating layer, and has required grooves, patterns, etc. smaller than the first mask. A second mask is placed over the second coating, grooves, patterns, etc. are formed using photoresist using the same method as described above, a second plating layer is further formed on the first metal plating layer, and then a second plating layer is formed on the first metal plating layer. A third film of photoresist is formed on the second plating layer, a third mask having required grooves, patterns, etc. is placed over the third photoresist film, and the photoresist is applied in the same manner as described above. A third plating layer is further formed on the second plating layer, and then a plating layer is formed on the plating layer in the above order as necessary to adjust its thickness. The photo ablation method is characterized in that a metal mask with greater rigidity is obtained by further welding a low melting point metal onto the plating layer while the multilayer plating layer remains attached to the model. How to make a mask for Yong.