JP2005212111A - Plate for screen printing, and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plate for screen printing, which can enhance both initial accuracy before printing and post-printing accuracy when a number of printing shots are repeated, and a manufacturing method for the plate. <P>SOLUTION: In this plate for the screen printing, wherein a print pattern part 5 is formed on a mesh screen 3 provided on a frame 2 in a tensioned state, the pattern part 5 is formed of a resin and provided with at least one opening 5a, and parts among the respective pattern parts 5 on the side of a printed surface A of the mesh screen 3 are coated with metal foil 6. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a screen printing plate and a method for producing the same.

  In general, as shown in FIGS. 16A and 16B and FIGS. 17A and 17B, a screen printing plate is formed by stretching a mesh screen 51 on a plate frame 50 with a predetermined tension. The mesh screen 51 is made of a photosensitive emulsion or a metal film, and has a structure in which a print pattern portion 52 or 53 formed with a predetermined print pattern is formed.

  By the way, in the case of the printing plate using the photosensitive emulsion, since the pattern formation is performed by lithography, the printing film coordinate accuracy (initial accuracy) before printing is excellent, but the rigidity of the emulsion film itself is low. Therefore, there is a problem that when the number of print shots is increased, the coordinates of the print pattern are likely to be shifted.

  On the other hand, in the case of a printing plate using the above metal film, since the rigidity of the print pattern portion is high, the print pattern coordinate deviation hardly occurs even if the number of print shots is increased. However, when the metal film is pressure bonded to the mesh screen by plating, the metal film itself is easily deformed, and the initial accuracy before printing cannot be obtained. Further, when the metal film is formed by electroforming, the plating current density distribution is generated due to the density of the printed pattern, and as a result, the film thickness accuracy is likely to deteriorate. Furthermore, when the metal film is on the squeegee sliding surface side of the mesh screen, there is a problem that the squeegee is easily worn at the edge of the printed pattern.

From the viewpoint of solving such problems, conventionally, a metal film is formed on the entire printing surface of the mesh screen, a resin film such as an emulsion is formed on the metal film, and a printing pattern is formed on the metal film and the resin film. (For example, refer to Patent Documents 1 and 2), or only the edge portion of the print pattern may be formed of a metal film and the remaining portion may be covered with an emulsion (for example, refer to Patent Document 3).
Japanese Patent Laid-Open No. 5-200967 Japanese Patent Publication No. 6-93655 Utility Model No. 2521340

  However, in the case of the structure in which the emulsion film is laminated on the metal film as in the above-described conventional patent document 1, there is a possibility that over-etching may occur when the metal film is etched, and for example, a fine pattern such as a spiral shape is formed. Is difficult. Further, in the case of Patent Document 2, it is basically a plate made of a metal film, and in the case of Patent Document 3, it is a structure in which a print pattern is formed with a metal film, both of which are initial accuracy of print pattern coordinates before printing. There is a concern that cannot be obtained.

  The present invention has been made in view of the above-described conventional situation, and can improve both the initial accuracy before printing and the coordinate accuracy when the number of print shots is overlapped, and can form a fine pattern. An object is to provide a printing plate and a method for producing the same.

  The invention of claim 1 is a screen printing plate in which a plurality of print pattern portions are formed on a mesh screen stretched on a plate frame. Each of the print pattern portions is formed of a resin, and has at least one print opening. And a portion between the print pattern portions on the printing surface side of the mesh screen is covered with a metal foil.

  The invention of claim 2 is characterized in that, in claim 1, the height dimension from the mesh screen to the surface of the printed pattern portion is larger than the height dimension from the mesh screen to the surface of the metal foil.

  According to a third aspect of the present invention, in the first or second aspect, the mesh screen is attached to the first screen stretched on the plate frame, and the print pattern portion is formed. The second mesh screen is made up of a second mesh screen.

  A fourth aspect of the present invention is the method for producing a screen printing plate according to any one of the first to third aspects, wherein a metal foil is coated on a portion between the print pattern portions on the printing surface side of the mesh screen. And a step of forming the printed pattern portion with a resin so as to have at least one printing opening.

  The invention of claim 5 is characterized in that, in claim 4, the metal foil is formed by plating.

  The invention of claim 6 is characterized in that, in claim 4 or 5, the metal foil is joined to the mesh screen by plating.

  A seventh aspect of the invention is characterized in that, in any one of the fourth to sixth aspects, the printed pattern portion is formed by applying a photosensitive emulsion to the mesh screen, and then exposing and developing. .

  According to the screen printing plate of the first aspect of the present invention, the print pattern portions are formed of resin, and the portions between the print pattern portions are covered with the metal foil. Both the initial accuracy) and the print pattern coordinate accuracy when the number of print shots is overlapped can be improved.

  Since the portions between the print pattern portions of the mesh screen are covered with metal foil, the rigidity of the screen printing plate itself can be increased, deformation due to squeegee sliding load during printing can be prevented, and printing shots can be obtained. Even if the number is repeated, it is possible to suppress the coordinate shift of the print pattern portion. Moreover, since the metal foil is formed on the printing surface side of the mesh screen, the squeegee sliding surface of the mesh screen can be smoothed and wear of the squeegee can be suppressed. Furthermore, since the print pattern portion is formed of resin, it is possible to form a fine pattern such as a spiral shape.

  In the invention of claim 2, since the height dimension from the mesh screen to the surface of the printing pattern portion is larger than the height dimension from the surface of the metal foil, the metal foil can be prevented from coming into contact with the printed matter, and the printing plate And the printed material can be improved, and as a result, the printing accuracy can be improved.

  In the invention of claim 3, since the mesh screen is constituted by the first screen and the second mesh screen, it is possible to improve the printing accuracy when performing screen printing.

  In the invention of claim 4, since the metal foil is formed in the portion between the print pattern portions on the printing surface side of the mesh screen, and the print pattern portion is formed of the resin, the initial accuracy before printing and the print shot are obtained. It is possible to produce a screen printing plate with high accuracy after printing when stacked.

  In the invention of claim 5, since the metal foil is formed by plating, a fine pattern can be formed as compared with the case where the metal foil is formed by laser processing, for example.

  In the invention of claim 6, since the metal foil is plated and joined to the mesh screen, for example, clogging can be prevented and the joining force can be increased as compared with the case where the metal foil is stuck with an adhesive.

  In the invention of claim 7, since the print pattern portion is formed of the photosensitive emulsion, it is possible to easily form a fine print pattern as compared with the case where the print pattern portion is formed by, for example, reactive ion etching (RIE). it can.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 5 are diagrams for explaining a screen printing plate and a method for manufacturing the same according to an embodiment of the present invention. FIG. 1 is a plan view of the screen printing plate, and FIG. 2 is a screen printing plate. FIG. 3 is an enlarged cross-sectional view of a printing pattern portion, FIGS. 4A to 4H are diagrams showing a process for producing a screen printing plate, and FIG. 5 is a screen. It is a figure which shows the manufacturing method of the printing plate.

  In the figure, reference numeral 1 denotes a screen printing plate in which, for example, a conductive paste is printed on a circuit board on which electronic components are mounted to form a circuit pattern. This is a rectangular plate frame 2 and a mesh screen 3. Are formed in a state where a predetermined tension is applied, and four print pattern portions 5 having a pair of printing openings 5a, 5a are formed in the mesh screen 3 with a predetermined gap therebetween. A metal foil 6 is formed on the portions between the print pattern portions 5 and the portions surrounding the print pattern portions 5. The metal foil 6 is formed in a rectangular shape inside the mesh screen 3 and is not formed on the inner peripheral portion of the plate frame 2 of the mesh screen 3, but is formed including the inner peripheral portion. May be.

  The mesh screen 3 is formed by braiding metal fine wires such as stainless steel. For example, an electroformed mesh screen in which a metal film is coated on the surface of a resin mesh having no conductivity, such as polyester, by vapor deposition or the like may be used as the mesh screen.

  Each of the printed pattern portions 5 is formed by applying a photosensitive emulsion to the mesh screen 3 and then exposing and developing the photosensitive emulsion. The photosensitive emulsion has a photocured form of polyvinyl alcohol polymer (acrylic). Or vinyl acetate) and photocrosslinking diazo resin for photocrosslinking, photopolymerization type that mixes polyvinyl alcohol / acrylic monomer and photopolymerization initiator, or hybrid that combines photocrosslinking type and photopolymerization type. The type is adopted.

  The metal foil 6 is integrally joined to the printing surface A side of the mesh screen 3 by electrolytic plating. The upper surface of the mesh screen 3 opposite to the printing surface A is a squeegee sliding surface B. The metal foil 6 is made of at least one of Au, Co, Cr, Cu, Mo, Ni, and W.

  As shown in FIG. 3, the height dimension h1 from the mesh screen 3 to the surface on the printing surface A side of the print pattern portion 5 is larger than the dimension h2 from the mesh screen 3 to the surface of the metal foil 6. ing. That is, a gap h is provided between the printed pattern portion 5 and the metal foil 6 so that only the printed pattern portion 5 comes into contact with the circuit board. As shown in FIG. 15, the dimension h1 and the dimension h2 are equal, and the gap h may not be provided. When providing this gap h, it sets suitably in the range of 1-100 micrometers, for example. By providing such a gap h, it is possible to prevent the metal foil 6 and the printed material from coming into contact with each other, and to improve the plate separation between the screen printing plate and the printed material.

  Next, one manufacturing method of the screen printing plate 1 will be described with reference to FIG.

[Photoresist formation process]
A square SUS substrate 10 having a plate thickness of 0.4 mm and an area of 200 × 200 mm is degreased and washed with a neutral detergent, and then a photoresist film 11 is patterned on the upper surface of the SUS substrate 10 by photolithography. . This photoresist film 11 was formed by using a photoresist PMER-NHC600 manufactured by Tokyo Ohka Kogyo Co., Ltd. and applying it to a thickness of 15 μm with a spin coater, followed by drying for 30 minutes in a 90 ° C. clean oven. .

  The photoresist film 11 of the SUS substrate 10 is exposed using i-line (wavelength 405 nm), followed by development and drying. Specifically, the developer NA-A5 manufactured by Tokyo Ohka Kogyo Co., Ltd. was used, and after developing for 2 minutes and washing with water for 5 minutes, it was dried in a clean oven at 110 ° C. for 30 minutes. . In this way, an opening 11a is formed in the metal foil forming portion of the photoresist film 11 (see FIG. 4A).

[Ni plating process]
A Ni plating film 12 having a thickness of 10 μm is formed in each opening 11a of the photoresist film 11 of the SUS substrate 10 by electrolytic plating (see FIG. 4B). This electrolytic plating was performed by immersing the SUS substrate 10 in a nickel sulfamate bath according to the formulation shown below and energizing for 30 minutes.

-Nickel sulfamate: 400 g / l
・ Boric acid: 30 g / l
・ Bath temperature: 50 ° C
・ PH: 4.1
・ Current density: 2 A / dm ²
[Smoothing process]
Polishing is performed with a commercially available sandpaper # 2400 so that the photoresist film 11 and the Ni plating film 12 are flush with each other (see FIG. 4C). Here, a Ni plating film may be formed by forming a photoresist film in advance so as to have the same thickness as the Ni plating film and performing electrolytic plating on the opening of the photoresist film. In such a case, polishing can be eliminated.

[Ni plating joining process]
The printing surface A side of the mesh screen 3 is brought into contact with the photoresist film 11 and the Ni plating film 12, and the mesh screen 3 is pressed into contact with the SUS base material 10 so that the three and 10 are in close contact with each other (FIG. 4D). reference). In this state, electrolytic plating is performed from the squeegee sliding surface B side of the mesh screen 3. A Ni plating film having a thickness of 3 μm is formed on the mesh screen 3 by this electrolytic plating. This electrolytic plating was performed by immersing the SUS substrate 10 and the mesh screen 3 in close contact with a nickel sulfamate bath and energizing for 10 minutes in substantially the same manner as described above. The mesh screen 3 is degreased and washed with a neutral detergent in advance.

[SUS substrate peeling process]
Next, the Ni plating film is peeled off from the SUS substrate 10 together with the mesh screen 3. In this case, when the photoresist film adheres to the Ni plating film, the photoresist film is removed with an alkaline solution or the like. Thus, the metal foil 6 integrally joined to the mesh screen 3 is formed (see FIG. 4E).

[Photosensitive emulsion coating process]
A photosensitive emulsion 15 is applied to the mesh screen 3 (see FIG. 4F). As shown in FIG. 5, the plate frame 2 is fixed to an inverted T-shaped support base 16 so as to form an inclination angle of about 70 degrees, and the photosensitive emulsion 15 is applied from the printing surface A side of the mesh screen 3. Apply with bucket 17. In this case, a bucket 17 having a size slightly smaller than the width of the plate frame 2 is used, and the photosensitive emulsion 15 protrudes on both sides A and B of the mesh screen 3 and is embedded on the edge side so that the metal foil 6 is embedded. It is applied four times so that the bucket 17 is slanted upward from the bottom while being inclined at ˜70 degrees. Thereafter, the photosensitive emulsion 15 is dried in a clean oven at 40 ° C. for about 15 minutes. Such emulsion coating / drying is repeated twice. If the gap h is not provided, the photosensitive emulsion 15 is applied so as to be the same height as the metal foil 6.

  Here, if necessary, the emulsion surface may be flattened. In this flat processing, the photosensitive emulsion is coated twice on the mesh screen so that it is lifted from the bottom, and before the photosensitive emulsion is naturally dried, a separately prepared flat processing film (for example, 100 μm thick PET film) Paste. At this time, when a gap is generated between the flat processing film and the photosensitive emulsion, the flat processing film is pressed. In this pressing step, the edge portion of the above-described bucket is pressed against the original film, and is slid upward from the bottom in the pressed state. After these steps, the mesh screen is left in a clean oven heated to 40 ° C. for 10 minutes to dry the photosensitive emulsion.

[Exposure process of photosensitive emulsion]
The positive film original plate 18 in which the opening 18a corresponding to the printing pattern is formed is closely fixed to the photosensitive emulsion 15 for exposure (see FIG. 4G). In this exposure, a metal hydride light source having a peak output in the diazo photosensitive band was used, and the integrated exposure amount at h-ray (wavelength 405 nm) was 1200 mJ / cm ² . As a result, the opening portion of the photosensitive emulsion 15 corresponding to the opening 18a of the positive film precursor 18 is locally cured by a photocrosslinking reaction. In addition, when the above-mentioned flat processed film has adhered, it is necessary to peel and remove before exposure.

[Development and drying process of photosensitive emulsion]
The photosensitive emulsion 15 is immersed in water at about 30 ° C. for 2 minutes, and then developed by rocking for about 1 minute. In this case, it is also possible to use a commercially available developing device for screen printing. Next, it is left in a clean oven at about 40 ° C. for about 15 minutes and dried. In this way, the screen printing plate 1 of the present embodiment is manufactured (see FIG. 4H).

  Next, an experiment conducted for confirming the effect of the present embodiment will be described.

  In this experiment, the initial accuracy before printing of the screen printing plate manufactured by the above-described manufacturing method and the post-printing accuracy after printing 5000 shots were measured. In this measurement, the amount of deviation from the measured coordinates with respect to the design coordinates was measured at 25 points in the plate, and the maximum amount of deviation was evaluated. For comparison, the same measurement was performed on a printing plate using a commercially available photosensitive emulsion and a printing plate using a metal film. Table 1 shows the specifications of the screen printing plate, photosensitive emulsion plate, and metal film plate.

  6-8 is a figure which shows the said experimental result. FIGS. 6A and 6B show the initial accuracy and post-printing accuracy of the screen printing plate of this embodiment, and FIGS. 7A and 7B and FIGS. 8A and 8B are commercially available, respectively. The initial accuracy and post-printing accuracy of photosensitive emulsion plates and metal film plates are shown. Each figure shows coordinates of 25 points / 135 mm □, and a square A in the figure shows a scale for coordinate accuracy with a side of 10 μn.

  First, in the case of the conventional photosensitive emulsion plate, although the initial accuracy before printing is good (see FIG. 7A), the printing pattern coordinate shift occurs after 5000 shots of printing, and the accuracy after printing deteriorates. (See FIG. 7B). In the case of a metal film plate, although there is no coordinate shift in the post-printing accuracy after 5000 shots of printing (see FIG. 8B), the initial accuracy is low due to deformation of the metal film itself at the time of pressure bonding. (See FIG. 8 (a)).

  On the other hand, in the screen printing plate of this embodiment, there is almost no coordinate deviation between the initial accuracy before printing and the accuracy after printing after 5000 shots (FIG. 6A). ), (B)).

  As described above, according to the screen printing plate 1 of the present embodiment, the four printing pattern portions 5 having the pair of printing openings 5a are formed of the photosensitive emulsion, and the portions other than the printing pattern portions 5 of the mesh screen 3 are formed. Is covered with the metal foil 6, so that both the initial accuracy before printing and the accuracy after printing when the number of printing shots are overlapped can be improved.

  Since the space between the print pattern portions 5 of the mesh screen 3 is covered with the metal foil 6, the rigidity of the screen printing plate 1 itself can be increased, and deformation due to a squeegee sliding load during printing can be prevented. Even if the number of shots is overlapped, the coordinate shift of each print pattern portion 5 can be suppressed.

  Moreover, since the said metal foil 6 was formed in the printing surface A side of the mesh screen 3, the squeegee sliding surface B side of the mesh screen 3 can be made smooth, and wear of a squeegee can be suppressed. Further, since each print pattern portion 5 is formed of a photosensitive emulsion, a fine pattern such as a spiral shape can be formed with high accuracy and ease.

  In the present embodiment, the dimension h1 from the mesh screen 3 to the printing pattern portion 5 is larger than the dimension h2 from the mesh screen 3 to the metal foil 6, that is, between the printing pattern portion 5 and the metal foil 6. Since the gap h is provided, the metal foil 6 can be prevented from coming into contact with the printed matter, the plate separation between the printing plate and the printed matter can be improved, and the printing accuracy can be improved.

  Since the metal foil 6 is formed by electrolytic plating, a fine pattern can be formed as compared with the case where the metal foil is formed by laser processing, for example. Moreover, since the said metal foil 6 was integrally joined to the mesh screen 3 by electroplating, clogging can be prevented and joining force can be raised compared with the case where it adheres, for example with an adhesive agent.

  In the above embodiment, the case where four print pattern portions 5 having a pair of print openings 5a are formed has been described as an example. However, the shape of the print pattern portion of the present invention is not limited to this, Various modifications are possible. 9 to 14 show first to third modified examples of the print pattern opening, respectively, in which the same reference numerals as those in FIGS. 1 and 2 denote the same or corresponding parts.

  9 and 10, 16 print pattern portions 20 having one print opening 20 a are formed at a predetermined interval, and a portion between the print pattern portions 20 and a peripheral portion thereof are formed on the metal foil 6. It is an example covered with.

  11 and 12, four print pattern portions 21 having four print openings 21 a are formed in parallel with a predetermined interval, and the metal foil 6 is formed between the print pattern portions 21 and surrounding portions thereof. It is an example covered with.

  FIGS. 13 and 14 show a set of four print pattern portions 22 having one print opening 22a, and a print pattern portion 23 having a print opening 23a having a size corresponding to the one set of print pattern portions 22. Is an example in which are alternately formed.

  In any of the first to third modifications, the space between and around each print pattern portion is covered with a metal foil, so that both the initial accuracy before printing and the accuracy after printing when printing shots are superimposed are improved. And the same effects as in the above embodiment can be obtained.

  Moreover, although the said embodiment demonstrated to the example the case where the printing pattern part was formed in one mesh screen, the mesh screen of this invention is the 1st screen which consists of the resin fiber stretched by the plate frame, For example, a second mesh screen made of a fine stainless steel wire and having a printed pattern portion formed thereon may be provided on the first screen. This is the invention of claim 3. The first screen is not limited to a mesh screen, and may be a screen made of a resin film, for example. In this example, the printing accuracy when performing screen printing can be further enhanced.

It is a top view of the plate for screen printing by one Embodiment of this invention. It is sectional drawing (II-II sectional view taken on the line of FIG. 1) of the said screen printing plate. It is sectional drawing of the printing pattern part of the said screen printing plate. It is a figure which shows the manufacturing process of the said screen printing plate. It is a figure which shows the manufacturing method of the said screen printing plate. It is a figure which shows the experimental result done in order to confirm the effect of the said embodiment. It is a figure which shows the said experimental result. It is a figure which shows the said experimental result. It is a figure which shows the 1st modification of the printing pattern part of the said embodiment. It is sectional drawing (XX sectional drawing of FIG. 9) of the said printing pattern part. It is a figure which shows the 2nd modification of the said printing pattern part. It is sectional drawing (XII-XII sectional view taken on the line of FIG. 11) of the said printing pattern part. It is a figure which shows the 3rd modification of the said printing pattern part. It is sectional drawing (XIV-XIV sectional view taken on the line of FIG. 13) of the said printing pattern part. It is sectional drawing of the plate for screen printing which shows the modification of the said embodiment. It is a figure which shows the printing plate by the conventional general photosensitive emulsion. It is a figure which shows the printing plate by the conventional general metal film.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Screen printing plate 2 Plate frame 3 Mesh screen 5, 20-23 Print pattern part 5a, 20a-23a Printing opening 6 Metal foil A Printing surface B Squeegee sliding surface

Claims (7)

  In a screen printing plate in which a plurality of print pattern portions are formed on a mesh screen stretched on a plate frame, each of the print pattern portions is formed of a resin and has at least one print opening, A screen printing plate characterized in that a portion between the print pattern portions on the printing surface side is covered with a metal foil.   2. The screen printing plate according to claim 1, wherein a height dimension from the mesh screen to the surface of the printing pattern portion is larger than a height dimension from the mesh screen to the surface of the metal foil.   3. The first mesh screen according to claim 1 or 2, wherein the mesh screen is stretched on the plate frame, and the second mesh screen is attached to the first screen and has the print pattern portion formed thereon. A screen printing plate characterized by comprising:   The method for producing a screen printing plate according to any one of claims 1 to 3, wherein a step of coating a metal foil on a portion between each print pattern portion on the printing surface side of the mesh screen, and the printing And a step of forming the pattern portion with a resin so as to have at least one printing opening.   5. The method for producing a screen printing plate according to claim 4, wherein the metal foil is formed by plating.   6. The method for producing a screen printing plate according to claim 4, wherein the metal foil is bonded to the mesh screen by plating.   7. The method for producing a screen printing plate according to claim 4, wherein the printing pattern portion is formed by applying a photosensitive emulsion to the mesh screen, and then exposing and developing. .

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