JPH08156227A - Squeegee blade and squeegee device - Google Patents

Abstract

PURPOSE: To sufficiently increase the printing pressure to a metal screen by inserting a metal plate over the entire length in the width direction of a printing plate so as not to directly expose the same to the main surface of the printing plate to constitute a squeegee blade. CONSTITUTION: A solid shaded part 1 shows a squeegee blade based on a polyurethane resin and a dotted line part 2 shows a steel plate composed of SUS and both parts 1, 2 are looked as a whole from the plane vertical to the width direction of a printing plate crossing a printing direction P at a right angle. An upper wavy line W shows that a uniform structure continues toward the holder of the blade provided to the lower part of a squeegee device. A metal plate to be said as a core material of a kind is inserted in the central part in the thickness direction of the squeegee blade over the almost total length in the length direction of the blade and the printing pressure to a metal screen plate including a mesh screen becomes easy to adjust or necessary printing pressure becomes easy to obtain. Further, the abrasion of the blade on the metal screen plate is suppressed.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen printing apparatus for mounting a solder paste on a predetermined position by screen printing before mounting an electronic component on an electronic circuit board, and more particularly to a squeegee apparatus. is there.

2. Description of the Related Art Among printing apparatuses used for screen printing on an electronic circuit board, particularly squeegee apparatuses, there are roughly the following two types. one,
A thin plate rectangular parallelepiped squeegee blade made of a hard plastic material such as polyurethane resin has been used for a long time, and the printing material placed on the screen plate immediately before the blade is slid on the screen plate. While moving, the material is imprinted on a printed circuit board (hereinafter, abbreviated as P-plate) as an object to be printed through the opening of the screen. It should be noted that, after the printing is completed, a blade having substantially the same structure as the blade is provided in front of the blade along the printing direction in order to reprint while collecting the material placed on the plate. There is also one. However, the blades provided before and after the above-mentioned blades have the same function independently of each other, that is, the blade performs the printing operation while attracting the printing material immediately before itself. On the other hand, the second one, which first appeared in the technical field relatively recently, that is, several years ago,
The thickness of the blade used in the former device is several mm or more, while the thickness is 0.1 mm to at most 0.2 mm.
A strip-shaped blade made of extremely thin metal steel plate is always provided at the bottom of the squeegee device, which is called the housing structure, at the bottom of the squeegee device. The upper surface of the screen plate from the state in which the two blades have cooperated to close and store the material sent from the printing material storage container to the squeegee blade portion. And the material is delivered. After printing, we cooperated again to collect and store the above surplus materials, and float away from the screen plate that was in contact with it until then.
It returns to the printing start point.

Incidentally, the concept, meaning, and structure of the chamber and housing structure, and the squeegee device of the structure, which have been used up to the above and also used below, are the same as those found in the document (Japanese Patent Application No. 5-39222). Or it is equivalent to it. For example, the chamber referred to in the present invention is the same as the previous paragraph ([0
As described in the latter half of (002]), it means a room that can store the printing material in the squeegee device as a container that can store the printing material. The rear wall at the same time corresponds respectively to the inner walls of the front and rear blocks of the entire squeegee device. As described above ([0002]), the supply of the printing material toward the lower part of the chamber, that is, the upper surface of the screen is performed by the rear blade attached to the movable wall, which is a part of the rear wall, moving backward, It is made through an opening formed between a front blade fixed to the front wall. As a matter of course, the printing material does not easily come out of the chamber so that the side wall connecting the front and rear blocks and the screen plate or P-plate perpendicular to the length direction of the squeegee blade, that is, the printing direction. An auxiliary side wall is also provided on the side wall in the width direction. As a result, a structure that does not come into direct contact with the outside air, together with the walls and ceiling, except for the supply port of the printing material and the inert gas or solvent for adjusting the material characteristics into the squeegee device, that is, the chamber In that sense, it is called a housing structure.

[Problems to be Solved by the Invention] In screen printing, metal screens have been frequently used from mesh screens in response to the recent trend toward higher definition of conductor lines, but as described in the previous section ([0003]). In the resin material squeegee blade used for the conventional squeegee device, P
-It is difficult to adjust the pressure (hereinafter, abbreviated as printing pressure) when printing the blade on the screen plate in order to finely control the amount of the printing material deposited on the plate. Furthermore, at the edge of the opening corresponding to the image pattern on the metal screen,
The tip of the blade has been scraped, and its wear is becoming extremely large.

On the other hand, when the metal screen is used, the degree of adhesion with the P-plate is stronger than that of the mesh screen, and it is thought that this is due to a kind of capillary phenomenon to the back surface (lower surface) of the printing material. It is apt to rotate around, and it is usually necessary to wipe the back surface at the end of each printing. In order to omit this process or the device for this purpose, a review is being started to adopt a mesh screen with higher definition. In the latter conventional example described in the previous section ([0003]), when such a mesh screen is used, the blade is extremely thin, and therefore the upper surface of the screen may be damaged at both ends in the length direction. It can happen. Further, regardless of the type of the screen, when the print material is temporarily separated from the upper surface of the screen plate after printing and returns to the print start point, the print material leaks from the closed squeegee blade portion and drops onto the screen plate. There is a fear (hereinafter abbreviated as "leakage"). This is because the two blades are made of ultra-thin steel plates having high hardness and are in direct contact with each other.

The present invention has been made in view of the above problems, and provides a structure in which each of the above-mentioned two conventional examples can produce complementary effects.

[Means for Solving the Problems] In order to solve the above problems, in the squeegee blade and the squeegee device using the same according to the present invention, first of all, the former example of the prior art (hereinafter, abbreviated as thick type). In the device corresponding to (1), a metal plate which is sufficiently thicker than the latter example of the prior art is inserted so as not to be exposed directly over the entire length of the squeegee blade and toward the screen plate. However, there are two main methods
One of the types is one in which a void for inserting the metal plate is formed in advance in an integrated blade, and the metal plate is inserted therein. Two, one blade has a front plate and a rear plate in a two-plate configuration, that is, a two-body type, along the printing direction, and each of the plates has a recess having the same length as that of the first plate. After being formed, the metal plate is sandwiched between the front and rear plates so as not to be directly exposed to the lower side or both ends in the length direction of the screen plate with the metal plate as the center.

Next, in the latter example of the prior art (hereinafter abbreviated as thin type), a polyurethane resin or the like is used so that the entire squeegee blade having an ultra-thin blade structure has a coating thickness similar to the thin blade thickness. The structure shall be covered with hard plastic. A so-called dip coating method or the like may be used as the coating method.

In the squeegee device according to the present invention, the various squeegee blades described above can be selectively used according to the intended use.

[Operation] In the squeegee blade according to the present invention, in the case of a thick type, a metal plate which should be called a kind of core material is provided in the center portion in the thickness direction and over almost the entire length in the length direction. By being inserted, it becomes easy to adjust the printing pressure on the metal screen plate, including the case of the mesh screen, or obtain the necessary printing pressure. Also, abrasion of the blade on the metal screen is suppressed.

Next, in the case of a thin type, since the whole is resin-coated, the mesh screen is not damaged, and the "leakage" on the return path to the starting point after printing is also eliminated.

Next, in the squeegee device according to the present invention, since the squeegee blade having the above structure is adopted, the overall printing performance and durability are increased.

[Embodiment] The gist of the present invention will be described below.
An example will be described with reference to the drawings. In FIG. 1, a solid shaded area 1 indicates a squeegee blade mainly made of a polyurethane-based resin that has been conventionally used, and a dotted area 2 indicates a steel plate such as SUS. As a whole, the printing direction (P) FIG. 6 is a cross-sectional view as seen from a plane perpendicular to the width direction (hereinafter, always abbreviated as width direction) of the printing plate that is orthogonal to. The upper wavy line (w) means that the illustration is omitted because a uniform structure continues toward the holder for holding the blade provided at the lower part of the squeegee device (the same applies hereinafter). FIG. 1 shows the resin integrally molded so that the metal plate can be inserted in advance so as to have a void portion over the entire length in the width direction (this is also the length direction of the blade at the same time). It represents a structure in which the metal plate is sandwiched,
The thickness along the printing direction of the metal plate is 1 to
As opposed to several mm, it is about several mm to several tens of mm as a whole. The figure also shows that although 2 is exposed at both ends in the width direction, it is not exposed downward toward the screen plate.

FIG. 2 is also one of the embodiments similar to the case of FIG. 1, and the meanings of the above-mentioned reference numerals are the same as in FIG. However, arrows S and S'mean almost the center of the thickness of the squeegee blade, and 1 indicates a rear part (1 (1)) and a front part (1 (2) along the printing direction by dotted lines S and S '. )) Can be divided. In other words, the blade is cut back and forth along the center line of the thickness, but has a structure in which a concave portion is provided in advance in the central portion over the entire width in the width direction. A metal plate (2 ') is attached so that it is sandwiched from the front and back. However, the bonding method may be various methods such as bonding with an adhesive, heat-sealing at the end in the width direction, and screwing when the device is configured as a squeegee device. The dimensions or dimensional ratios of the main parts in FIG.
It is similar to the case of.

1 and 2, the cross section of one blade is shown in common, but two blades are incorporated into one squeegee device one by one in the front-back direction along the printing direction. When using it, of course, but even in that case, the above-mentioned respective ones are independent from each other and do not function cooperatively at the same time. That is, the functions of both are essentially the same, and the operation timings are merely divided into the forward path and the backward path of printing. Furthermore, it is because the attachment of the two types of blades shown in FIGS. 1 and 2 and described above does not cause more difficulty or trouble than before.

FIG. 3 is a cross-sectional view of a squeegee blade that can be used in a squeegee device having a housing structure, viewed from the same direction as described above, in which 3 is a blade made of a steel plate such as SUS and 4 is a dip coating or the like. It is a hard plastic such as polyurethane resin that coats the blade.
This figure is different from the previous figure in which the metal plate is inserted into the center of the thickness of the blade of the conventional structure, but the structure of the blade of the conventional structure made of metal is coated with resin. Is represented. For the sake of clarity, FIG.
Although it is drawn in almost the same size as in FIG. 2, the dimensions or dimensional ratios of the main parts in FIG. 2 are essentially different from those in FIGS. That is, the total thickness is several tenths, and the dimensional ratio between the main parts is about 1: 1. For example, the thickness of 3 is 0.1
If the thickness is mm, the total thickness may be about 0.2 to 0.4 mm.

Incidentally, the blade shown in FIG.
By forming the squeegee blade part with one set, as described above,
It is particularly useful in a squeegee device having a housing structure, but since it is not necessary to provide a special difference in the structure of each of the above-mentioned one sheets, only one sheet is represented. The structure of the squeegee device incorporating these squeegee blades is
The illustration is omitted for the same meaning as in the case of FIGS. When the blade is installed in the squeegee device,
Unlike the case of FIGS. 1 and 2, the angle formed by the main blade surface with respect to the upper surface of the screen is sufficiently smaller than 90 °. For details, refer to the document described in [0003].

[Effect of the Invention] As can be easily understood from the above description, the present invention can exert the following effects in screen printing.

By using a structure in which a metal plate is embedded or sandwiched over the entire length of the thickness center of a hard plastic squeegee blade, a sufficiently large printing pressure is exerted on the metal screen of the blade. It is possible and easy to adjust, and the degree of abrasion is drastically reduced. Therefore, it is possible to control the amount of the printing material deposited on the P-plate by the squeegee device using the blade, and to obtain a plate with good image quality. Will be easier.

By coating the entire ultra-thin blade squeegee blade made of steel plate with resin, which is useful in a squeegee device having a housing structure, damage to the mesh screen of the blade is eliminated and the "leakage" phenomenon is almost eliminated. However, various uses of the squeegee device using the blade and acquisition of good plate results are achieved.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part showing an embodiment of a squeegee blade.

FIG. 2 is a longitudinal sectional view of an essential part showing an embodiment of a squeegee blade.

FIG. 3 is a longitudinal sectional view of an essential part showing an embodiment of a squeegee blade.

[Explanation of symbols]

 1, 1 (1), 1 (2), 4 Resin 2, 2 ', 3 Metal plate P Printing direction W Surface not shown S, S' Contact surface

Claims (4)

[Claims] 1. A metal plate is embedded over the entire length of the printing plate in the width direction and is not exposed directly to the main surface of the printing plate, and slides on the screen plate in screen printing. A squeegee blade configured for use in a squeegee device 2. A screen comprising a metal plate sandwiched between two front and rear hard plastic plates so as not to be directly exposed to the main surface of the printing plate over the entire length of the printing plate in the width direction, and a screen. A squeegee blade configured to be used in a squeegee device that slides on a screen plate in printing 3. A squeegee blade entirely covered with a hard plastic material and adapted to be used in a squeegee device having a housing structure, which slides on a screen plate in screen printing. 4. A squeegee device for screen printing, which is configured to use the squeegee blade according to claim 1.