JP2821633B2 - Screen printing screen - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a screen for screen printing. INDUSTRIAL APPLICABILITY The present invention can be generally used for applying and printing various printing agents, and can be used, for example, for applying and printing a printing ink and for applying and printing a photosensitive emulsion in a desired pattern. INDUSTRIAL APPLICABILITY The present invention can be used for, for example, photosensitive emulsion for forming a circuit of a semiconductor device, wiring printing on a printed circuit board, or printing a thin film resistor.

[Summary of the Invention]

The screen for screen printing of the present invention includes a metal plate provided with a printing agent permeable portion by being formed in a lattice shape, and the printing agent permeable portion is formed of a patterned printing material impermeable material, thereby forming a metal plate. When printing is performed by applying a printing agent to this screen by coating by the thickness, when the printing agent is used, the thickness of the metal plate in the printing agent-permeable portion other than the printing agent-impermeable material is coated. The thickness of the metal plate allows the printing to be performed with good film thickness controllability and the thin film printing with a small printing film thickness. It was made possible.

[Conventional technology]

Conventionally, as a screen used for screen printing,
A screen having a so-called woven structure formed by weaving a fibrous material is mainly used.

This is done by weaving synthetic fibers such as polyester, nylon, and tetron, or stainless steel made into a fibrous form into a net shape, and printing by passing a printing agent such as printing ink through the gaps between the fibers (mesh). It is like that.

For example, FIG. 5 is an enlarged view of a screen made of stainless steel mesh in which stainless fibers are woven in a net shape (drawing from a photograph). In this example, wefts a and warps b alternately as shown in the figure. It is woven to form a net made of stainless steel fibers, and the gap between each of the yarns a and b is a transmission portion d. Such a screen forms a pattern c with a material (usually referred to as a resist) through which a printing agent does not pass, and a transmission portion d which is not covered with the pattern c.
The printing is performed in a desired pattern by allowing the printing agent to pass therethrough.

For example, when a photosensitive emulsion is applied as a resist, the pattern c is formed with a structure as shown in the cross section in FIG.

 However, the conventional screen as described above has a structure in which a fibrous material is woven, so that the dimensional stability method is poor.

Thin film printing is difficult (for example, in the case of emulsion printing, if the emulsion is applied thinly on the screen, the network irregularities of the screen will be reflected on the emulsion surface as it is and printed as it is. Is limited).

There is a problem.

[Problems to be solved by the invention]

Under the above circumstances, it is conceivable that the metal plate is formed in a grid shape or a mesh shape (hereinafter, simply referred to as a "grid shape") to provide a screen for screen printing (for such a concept, for example, Nikkei McGraw-Hill "Nikkei Micro Devices" October 1989, p.

However, this concept alone does not always provide sufficient effects on printing accuracy, controlling the thickness of the printing agent, and reducing the thickness.

When printing is performed using a grid-like metal plate as a screen plate, the following method is employed.

First, as shown in FIG. 7 (a), for example, a photoresist is applied as a printing agent impermeable material 21 on the metal plate 1. In this case, the print impermeable material 21 is located in the transmission portion 11 of the metal plate 1 and on the metal plate 1.

Next, the printing agent impermeable material 21 is patterned,
As shown in FIG. 7 (b). In the case of a photoresist, a pattern may be formed by an exposure phenomenon by ordinary photolithography.

Next, the screen on which the desired pattern is obtained as described above is placed on the substrate 3 to be printed, for example, a base, and various printing agents 51 as printing materials are applied to the squeegee 40.

Then, the printing agent 51 penetrates from the printing agent transmitting portion 11, and desired printing is performed on a portion which is not covered with the pattern 2 of the printing agent impermeable material.
The printed shape as shown by is obtained.

However, in this method, as understood from FIGS. 7C and 7D, the height h of the printing pattern 5 formed by the printing agent is equal to the height of the pattern 2, that is, the printing agent impermeable material 21.
, And is at least higher than the height (thickness) of the metal plate 1 as a screen plate. This is because the printing agent impermeable material 21 is formed by being applied on the metal plate 1.

Therefore, there is a limit to reducing the height h of the print pattern 5, and a reduction in the thickness cannot be realized. The film thickness (height h) of the print pattern 5 is determined by the thickness of the printing agent impermeable material 21 formed by coating on the metal plate 1. Since it is often used and undergoes processing such as exposure and development, the controllability of the film thickness when formed as a resist pattern or the like is not always good. Therefore, the print pattern 5
It is also difficult to precisely control the film thickness.

The present invention is intended to solve the above problems, and an object of the present invention is to precisely determine the film thickness of a printing agent printed in a desired pattern with good controllability and reduce the film thickness. An object of the present invention is to provide a screen for screen printing which can be made thin.

[Means for solving the problem]

The screen of the present invention is a screen printing screen including a metal plate provided with a printing agent transmitting portion by forming a grid, the printing agent transmitting portion,
A screen printing screen characterized by being coated with a patterned printing material impermeable material by the thickness of the metal plate. The present invention has achieved the above object by adopting this configuration.

The configuration of the present invention will be described below with reference to FIG. 1 showing an embodiment of the present invention, which will be described in detail later.

That is, the screen for screen printing of the present invention has the first
As illustrated in the figure, the metal plate 1 has a configuration in which a printing agent transmitting portion 11 is provided by forming the metal plate 1 in a lattice shape (FIGS. 1A to 1C). As shown in FIG. 1 (b), the agent transmitting portion 11 is coated with a patterned printing agent impermeable material 21 by the thickness of the metal plate 1.

As a result, when printing is performed using this screen, that is, when a printing agent 51 is applied and printed on the printing medium 3 by a squeegee 40 as shown in FIG. 1C, for example, a pattern formed by the printing agent 51 is formed. That is, the print pattern 5 is the first
As shown in FIG. 3D, the thickness (height) H of the metal plate 1 is exactly the same as the thickness T of the metal plate 1.

Therefore, the thickness H of the obtained print pattern 5 is limited to the same size as the thickness T of the metal plate 1. The thickness T of the metal plate 1 is precisely determined because the material is metal, and does not change due to processing, and thus the thickness H of the print pattern 5 can be precisely controlled. Further, the film thickness H of the print pattern 5 does not need to be larger than the thickness of the metal plate 1 unlike the related art (refer to FIGS. 7 (c) and 7 (d) for explaining the related art). It is possible to Therefore, precise and thin-film printing becomes possible. Therefore, the present invention is suitable as a screen for printing fine fine patterns. Further, when a photoresist is used as the printing agent impermeable material, the resolution can be increased because the resist can be made thin. Also,
Since thin film printing is possible, it is also suitable for printing when the printing agent is an expensive paste (noble metal or the like). Furthermore, when a thin film resistor is formed, a thin film resistor can be formed, and as a result, a high-resistance resistor can be formed. The metal plate has good abrasion resistance due to its material, and the change in the thickness T of the metal plate 1 is small even when used repeatedly. For this reason, variations in printing can be suppressed. In the case of a thin film resistor, a precise, high-resistance one can be formed stably with good reproducibility. Further, the screen of the present invention can be suitably used for forming wiring for bonding a fine semiconductor element, and can be effectively used in many fields.

In the present invention, the metal plate forming the screen plate has a printing agent permeable portion by being formed in a grid shape, but the grid shape includes the mesh (mesh) shape as described above, and as a printing screen plate. Any structure may be used as long as it has a stiffness that can function and has a portion where a printing agent is transmitted.

 The material of the metal plate is arbitrary.

In order to form a lattice, a processing means by an etching method or an electroforming method can be preferably used. The finish is preferably roughened. This is because the adhesion is improved. In addition, since the surface is roughened to lose gloss, it is advantageous when a photoresist is used as the printing agent impermeable material. If the surface is glossy, the resist resolution may decrease when exposed in the resist process.

When a metal plate is obtained by an etching method, the material is preferably stainless steel or nickel.
When a metal plate is obtained by an electroforming method, the material is preferably nickel.

The cross-sectional shape of the metal plate is not particularly limited, but the shape obtained by the electroforming method is almost circular, and the shape obtained by the electroforming method is preferable in terms of the permeability (permeability) of a printing agent such as an ink emulsion.

Although the thickness of the metal plate is not particularly limited, the thickness of the printing agent (printing thickness) is determined by the thickness, so that the metal plate is formed to have a desired thickness. The thickness is preferably formed precisely.

Next, in the present invention, the printing agent impermeable material is a material that obtains a desired printing pattern in a portion other than the pattern formed by the printing material, and therefore, a material that forms an impermeable portion that does not transmit the printing agent. Is optional. Use of a photosensitive resist or other photosensitive emulsion is advantageous because an arbitrary pattern can be obtained by exposure and development in a photographic printing process. However, it is not limited to this. Any material can be used as long as it can be patterned into a desired shape and does not transmit the printing agent.

In general, the printing agent-impermeable material can be coated by using a metal squeegee to smoothly apply it to the metal plate from both sides (see FIG. 3A described later), but the coating means is not particularly limited. There is no.

In the screen of the present invention, the metal plate is coated with a printing agent impermeable material by its thickness,
This does not necessarily have to be strictly equivalent to the wall thickness, but may be applied to a thickness close to the wall thickness in accordance with the accuracy and film thickness required for the final print pattern.

〔Example〕

Hereinafter, an embodiment of the present invention will be described. However, needless to say, the present invention is not limited to the embodiments described below.

Example 1 In this example, the present invention was applied to the formation of a printed pattern of an electronic material. In particular, a resist emulsion was used as a printing agent impermeable material, and a resist pattern was formed by photolithography. In order to obtain an inverted print pattern.

In this embodiment, the plate shown in FIG. 2 was used as the metal plate 1 forming the screen plate. That is, as shown in FIG.
Was precisely formed to have a predetermined thickness of 10 to 50 μm. Further, as shown in FIG. 2 (b), by forming them in an orthogonal lattice shape, a square opening close to a square was formed, and this was used as a printing agent transmitting portion 11. The distance l ₁ (line width) between the apertures was set between 15 and 50 μ, and the large l ₂ (opening diameter) of one side of the aperture 11 was set between 30 and 60 μ.

The metal plate 1 of the present invention was formed by etching or electroforming, and was finished with a rough surface.

In this embodiment, as shown in FIG. 1 (a), the printing material impermeable material 21 is coated on the entire surface of the printed material transmitting portion 11 which is the opening of the metal plate 1 by the thickness of the metal plate 1. I do. Specifically, as shown in FIG. 3 (a), a squeegee 4 having clamping portions 41, 42 sandwiching the metal plate 1 from both sides is used, and a printing agent impermeable material 21 'which is a resist is shown in the figure. By moving the metal plate 1 in the direction of the arrow in FIG.
The printing agent impermeable material 21 is embedded in the substrate and coated smoothly.

As a result, as shown in FIG. 1 (a) and FIG. 3 (b)
As a result, a structure in which a resist emulsion which is a printing agent impermeable material 21 is applied to the entire printing agent transmitting portion 11 of the metal plate 1 is obtained.

Next, specifically, the resist emulsion is dried. Next, exposure and development are performed to obtain a printing agent impermeable material 2 formed in a desired pattern (FIGS. 1 (b) and 4).

Printing is performed using the screen according to the present embodiment obtained as described above, as follows.

As shown in FIG. 1 (c), the screen is placed on a substrate or the like, which is the substrate 3 to be printed, and a printing agent 51 is applied using a squeegee 40 to perform printing.

As a result, as shown in FIG.
The print pattern 5 having the same thickness H as the thickness T is obtained.

According to this example, it was possible to achieve thin film printing with a sufficiently thin film thickness, but with good controllability of the film thickness.
Since the squeegee 40 rubs not on the resist surface but on the metal surface, there is no abrasion of the pattern. Also, the wear of the metal surface itself is extremely small. In fact, even if you print many sheets for a long time,
No change was observed in the resulting print. Therefore, a highly reliable and highly reproducible product can be obtained without variation in quality.

For example, in addition to the formation of the emulsion, when the bonding structure of the semiconductor wafer was formed by printing as described above, a 150 μm bonding wiring was successfully formed. This is significantly more advantageous than a conventional plating method that requires labor.

In addition, the thin-film resistance was obtained with good quality and with no variation in resistance value with high reliability.

Applicable to other various electronic materials, favorable results were obtained.

〔The invention's effect〕

As described above, the screen printing screen of the present invention is:
There is an effect that the thickness of the obtained print can be precisely controlled and printing can be performed with a sufficiently thin film.

[Brief description of the drawings]

1 (a) to 1 (d) are process diagrams for explaining one embodiment of the present invention, FIGS. 2 (a) and 2 (b) are diagrams showing the configuration of a metal plate of the embodiment, and FIG. (A) and (b) are explanatory diagrams when a printing agent impermeable material is applied to obtain a screen, and FIG. 4 is a configuration diagram of the screen of this embodiment (having a printing agent impermeable material after patterning). FIG. FIG. 5, FIG. 6 and FIG. 7 (a) to (d)
FIG. 2 is a diagram showing a conventional technique. 1 ... metal plate, 11 ... printing material transmission part (opening), 21
... Printing agent impermeable material (resist), 2... Patterned printing agent impermeable material (resist pattern).

Claims (1)

(57) [Claims] 1. A screen printing screen provided with a metal plate having a printing agent transmitting portion formed in a lattice shape, wherein the printing agent transmitting portion is formed by a patterned printing agent impermeable material. A screen for screen printing, characterized in that it is coated by the thickness of a metal plate.