JPS62127461A - Formation of film pattern layer - Google Patents

Abstract

PURPOSE:To form film metal pattern layer free from aberration and shading, by pressing and adhering a substrate and a mask while using a mask supporting plate and pressing means, at vapor depositing a metal on the substrate such as lead frame in pattern state by pattern forming mask. CONSTITUTION:An Al 4 in a crucible 5 is heated and vaporized by an electron gun 6 in a vacuum chamber 1 to vapor deposit Al on a lead frame plate 3 surface such as Fe-Ni plate in pattern state by the mask 21 for forming pattern. In this case, the mask 2 is made of thin metal sheet of 0.05-0.5mm thickness and windows 2a for forming pattern are provided thereto. Simultaneously, the frame 3 and the mask 2 are tightly adhered by the mask supporting plate 7 having larger windows 7a than the windows 2a and about 20mm thickness and pressing means composed of plural weights 8 of 0.5-1kg per one, to form pattern of vapor deposited Al free from aberration of mask and shading of mask contours.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a thin film pattern J that can form a vapor deposition pattern layer, etc. without positional shift on a substrate using a mask having patterned windows.・Regarding the method of forming No. 9.

[Conventional technology]

When forming a vapor-deposited film layer of metal or the like only in a predetermined area on a substrate, a method is generally adopted in which vapor deposition is performed by covering the surface of the substrate with a mask having patterned windows. For example, I
For example, when aluminum is vapor-deposited on the bonding area of a lead frame for C, as shown in Figure 2,
A pattern forming mask 2 is provided in the chamber 1 to maintain a constant degree of vacuum, and the lead frame 3 is attached to the mask 9 (D).
- side, that is, the side opposite to the crucible 5 containing the aluminum 4, and the aluminum evaporated from the inside of the crucible by electron beam heating by the electron gun 6 is transferred to the window 2a of the mask 2.
The bonding area 3a of the frame 3 that is not covered by the mask is vapor-deposited in spots until it reaches a predetermined thickness, for example, 2 to 10 μm.

[Problem that the invention seeks to solve]

However, according to this method, the substrate and patterning mask become heated due to radiant heat generated by heating the evaporation source and thermal energy carried by the evaporated material, and expand based on their respective coefficients of thermal expansion. However,
The substrate and the mask are not necessarily made of the same material, and their positions and heat receiving areas are also different, so their coefficients of thermal expansion may be significantly different, and the heat rays and rays they receive may be significantly different.
If there is a large difference in the amount of energy, the vapor deposition pattern layer will be misaligned due to the difference in thermal expansion between the substrate and the mask.

Furthermore, if the heat distribution differs locally, distortion occurs and the mask rises from the surface of the substrate, blurring the boundary between the evaporated area and the non-evaporated area.

Furthermore, if the thickness of the mask is increased to increase its strength in order to reduce distortion due to heat, a portion of the evaporation area of the substrate that is in the shadow of the evaporation source will appear, resulting in evaporation boundaries (blurring).

In addition, a high-strength, thick mask is expensive to manufacture and cannot be used continuously for a long period of time due to the difficulty of correcting accumulated strain caused by repeated use, and is therefore economically disadvantageous.

. On the other hand, demands for improving the accuracy of deposited films and the like and further reducing manufacturing costs are increasing, and for this reason, solving the above-mentioned problems has become a major issue.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention supports a pattern-formed N mask overlaid on a substrate by a mask support plate held inside a chamber or the like, and uses a pressurizing means to support the substrate and the support plate as a tool. The mask is pressed from the opposite side, and under this condition, the thin film material is deposited and grown on the area of the substrate that is not covered by the mask.

In addition, the mask support plate used has a window larger than the window made in the mask, and is brought into close contact with one surface of the mask on the side of the supply source of the thin film material.

According to this method, since the substrate and the mask are held between the mask support plate by the force applied by the pressure means,
This prevents the mask from lifting off the substrate surface due to thermal distortion. Therefore, first of all, this eliminates the blurring of the pattern layer boundary caused by the lifting of the mask.

In addition, since no lifting occurs, it is possible to reduce the mask thickness and eliminate shadows in the thin film formation area.
This also eliminates blur caused by shadows.

Further, since the positions of the substrate and the mask are restrained by the force of the pressurizing means, misalignment of the thin film layer due to a difference in thermal expansion is also suppressed.

〔Example〕

FIG. 1 shows an example of a vapor deposition apparatus using the present invention, in which 1 is a chamber, 2 is a pattern forming mask equipped with a window 2a for opening the vapor deposition area of a substrate, for example, a lead frame 3, and 4 is a Aluminum is an evaporation source, 5 is a crucible, 6 is an electron gun for heating the aluminum, 7 is a mask support plate with a window 7a corresponding to and larger than the window 2a, and 8 is a lead frame 3 and a mask 2a. This is a pressure means for pressing the support plate 7 side.

The pattern forming mask 2 has a thickness of 0.05 to 0.5
It is preferable to make it a dwarf. If it is less than 0.05 mN, wrinkles will occur in the area of the window brightness of the support plate 7, so the shape and dimensional accuracy of the vapor-deposited pattern layer cannot be maintained.
This is because if it exceeds 5 mm, a shadow will be created in the lead frame's evaporation process IJ that causes blurring of the evaporation source.

In addition, as for the material of the mask, for example in the case shown in the figure, the lead frame is generally made of Fe-42Ni, so choose the same Fe-42Ni, or choose a material whose coefficient of thermal expansion is less than twice that of the substrate. is desirable. If it exceeds twice the window brightness, a gap will be created between the mask and the substrate within the window brightness area due to thermal expansion of the mask within the window brightness area, and blurring will easily occur at the boundary of the vapor deposited layer.

The material of the mask support plate 7 is not particularly limited. For example, low carbon steel plate, stainless steel plate, etc., which are inexpensive and have good workability, may be used. In short, the attachment to the pressurizing means chamber 1 may be fixed in a non-removable manner;
It is preferable to hold it removably in the chamber so that it can be replaced. Furthermore, a window 7 made in this support plate
a is made large enough to prevent the formation of shadows caused by the support plate for the evaporation source in the evaporation area of the substrate.

Further, the pressurizing means 8 may be one that applies pressing force to the substrate and the mask using its own weight, or one that applies pressing force using spring pressure, fluid pressure, or the like.

Note that in the illustrated apparatus, a plurality of masks and substrates are collectively supported by - mask support plates 7, but the support plate 7 is structured to support one mask and one substrate. It's okay.

Next, a specific example of the method of the present invention using the above device will be shown.

The pattern forming mask 2 of the apparatus shown in FIG. 1 has a thickness of 0.
A Fe-Ni plate with a thickness of 3 mm is used, and a low carbon steel plate with a thickness of 20 mm is used for the mask support plate 7.
A total of three weight plates each weighing 05 to 1.0 Kl are used as shown in the figure, and the lead frame 3 and mask 2 are pressed against the support plate 7 by the electric switch of each weight plate. Fe-42Ni
Aluminum vapor deposition was performed on the bonding area 3a within a range of 1.5 mm from the tip of the frame 3 consisting of. The evaporation conditions at this time are vacuum degree in chamber 1 = 10 T
orr, and the lead frame temperature was 300'C.

Also, for comparison, the pattern forming mask has a thickness of 1 mm.
Low carbon steel (coefficient of thermal expansion 13X1 under 300'C
0 crn/”C) using the device shown in Figure 2,
Aluminum vapor deposition was performed on the same lead frame under the same conditions without applying pressure.

For each 300 pieces of products obtained by the above method,
1 from the frame tip of the aluminum vapor deposited layer on the lead frame
．． The table below shows the results of examining the positional deviation size and the number of defective blurring at the deposition boundary using the 5 mtn portion as the reference line.

This result shows that the present invention is extremely effective in preventing misalignment and blurring of thin films.

For convenience, the embodiments have been described using aluminum vapor deposition on a lead frame as an example, but the substrate and thin film materials used in the present invention are not limited to the lead frame and aluminum.

Further, the present invention is effective not only for vapor deposition but also for forming thin film pattern layers by other methods using masking, such as sputtering and vapor phase reaction growth.

〔effect〕

As described above, according to the present invention, thin film formation such as vapor deposition is performed by sandwiching the substrate and the mask stacked on the surface between the mask support plate and the pressure means, so that thermal distortion deformation of the mask and the surface of the substrate are prevented. It is possible to completely eliminate the blurring of the thin film pattern layer boundary caused by the shadow of the mask.

In addition, by restricting the positions of the substrate and mask, changes in the relative position of the substrate and mask due to differences in thermal expansion are prevented, not only when they are made of the same material, but also when they are made of the same material. , Therefore, the misalignment of the thin film pattern layer is also reduced.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an example of application of the method of the present invention to a vapor deposition apparatus, and FIG. 2 is a cross-sectional view showing an example of a vapor deposition apparatus using a conventional method.

Claims (4)

[Claims] (1) A mask support plate with a window larger than the window in the pattern-forming mask stacked on the substrate is held inside a chamber or the like on the thin film material supply source side. At the same time, the substrate and the mask are pressed from opposite sides by a pressurizing means using the support plate as a support, and under this condition, a thin film material is attached and grown on the area of the substrate not covered by the mask. A method for forming a thin film pattern layer. (2) Claim (1) characterized in that the mask used has a coefficient of thermal expansion not more than twice that of the substrate and a thickness in the range of 0.05 to 0.5 mm. A method for forming a thin film pattern layer as described in Section 1. (3) The method for forming a thin film pattern layer according to claim (1) or (2), wherein the mask support plate is detachably held inside a chamber or the like. (4) Claims (1) to (3) characterized in that the mask support plate has a size and shape that can collectively hold a plurality of masks and substrates. The method for forming a thin film pattern layer according to any one of the above.