KR102521506B1 - Squeegee blade for conductive paste printing and manufacturing method thereof - Google Patents

Abstract

In the present invention, one end is coupled to the squeegee holder and the other end protrudes from the squeegee holder, and conductive paste printing prints the conductive paste by moving along a trench of a printed circuit board in a state in which the conductive paste is supplied to the traveling direction side. In the squeegee blade for squeegee and method for manufacturing the same, the technical point is that a micropattern is formed in a protrusion shape on one or both surfaces of the blade in contact with the trench. Accordingly, by forming a micropattern on a blade of a flexible printing squeegee, it is possible to increase the filling ability of the conductive paste in the trench. In addition, by forming a micro-pattern on the blade, an effect of squeezing several times with one squeezing can be obtained, and a separate pressure can be applied to the squeezed conductive paste by being made of a flexible elastic material.

Description

Squeegee blade for conductive paste printing and manufacturing method thereof {Squeegee blade for conductive paste printing and manufacturing method thereof}

The present invention relates to a squeegee blade for conductive paste printing and a method for manufacturing the same, and more particularly, to a squeegee blade for conductive paste printing that increases the fillability of a conductive paste in a trench by forming a micropattern on a flexible printing squeegee blade, and It is about its manufacturing method.

In general, printed circuit boards embedded as main parts of electric and electronic devices such as touch screen panels, solar cells, organic light emitting diode display panels, etc. have copper films (Cu film) An electronic circuit wiring in which a conductive layer such as is printed in a predetermined pattern is formed. Then, small electronic components such as semiconductor chips or resistor chips are mounted so as to be electrically connected to the electronic circuit wiring. A screen printing method is mainly used as a method for mounting such small electronic components on a printed circuit board. The screen printing method involves soldering and bonding small electronic components such as semiconductor chips to a printed circuit board by using conductive paste or cream solder as a bonding material, using a squeegee device of a screen printer. It consists of a method of uniformly applying a conductive paste to electronic circuit wiring printed on a printed circuit board. Then, the conductor leads of the electronic component are seated thereon and the conductive paste is cured, so that the conductor leads of the electronic component are soldered to the electronic circuit wiring on the printed circuit board and electrically connected.

Such a conventional squeegee device is 'Korean Intellectual Property Office Publication No. 10-2011-0107770 squeegee for paste printing, paste printing device, manufacturing method of wiring board', 'Korean Intellectual Property Office Registered Utility Model No. 20-0463702 squeegee device for screen printer' It is for applying conductive paste to a printed circuit board in a flexible state, such as a squeegee, which is mainly made of a material having strength, and screen-prints the conductive paste in a state in which its shape is maintained without changing by contact or pressure.

Therefore, when screen printing is performed using the squeegee on a printed circuit board having high strength and not deformed in shape rather than a flexible printed circuit board, the conductive paste does not fill the trench meticulously. In particular, in the case of a trench having a '+' shape, it is more difficult to fill the conductive paste. In addition, since most of the technologies related to the conventional squeegee device are developed in the direction of changing the holder rather than the blade itself, it is difficult to expect a fundamental improvement in the fillability of the conductive paste.

Korean Intellectual Property Office Publication No. 10-2011-0107770 Korea Intellectual Property Office Registered Utility Model No. 20-0463702

Accordingly, an object of the present invention is to provide a squeegee blade for conductive paste printing and a method for manufacturing the same, which increase the fillability of the conductive paste in trenches by forming micropatterns on the flexible printing squeegee blade.

In addition, due to the formation of micro-patterns on the blade, the effect of squeezing several times with one squeezing can be obtained, and conductive paste printing that can apply separate pressure to the squeezed conductive paste by being made of a flexible elastic material. To provide a squeegee blade for use and a manufacturing method thereof.

For the above object, one end is coupled to the squeegee holder and the other end protrudes from the squeegee holder, and the conductive paste is printed by moving along the trench of the printed circuit board in a state in which the conductive paste is supplied to the traveling direction side. In the squeegee blade for printing, it is achieved by a squeegee blade for conductive paste printing, characterized in that a micropattern is formed in a projection shape on one or both surfaces of the blade in contact with the trench.

Here, the plurality of micropatterns are uniformly arranged in the horizontal direction and stacking direction, and the micropatterns disposed on the top and bottom of one micropattern are arranged on the top and bottom so that the micropattern and the corresponding micropattern are misaligned in width. It is preferable that the micropattern or the micropattern is an oblique micropattern in which a plurality of micropatterns are regularly arranged obliquely so as to form an angle of 30 to 60°.

Alternatively, a plurality of the micropatterns are regularly arranged in the horizontal direction and stacking direction, and the micropatterns disposed on the top and bottom of one micropattern are arranged on the top and bottom so that the micropattern and the corresponding micropattern are misaligned in width. micropattern; A plurality of slanted micropatterns are regularly arranged at an angle of 30 to 60°, and the horizontal micropattern and the slanted micropattern form a single unit pattern and are repeatedly formed along the longitudinal direction of the squeegee blade. desirable.

In addition, in the micropattern, the height of the protrusion protruding from the squeegee blade is made of 20 to 50 μm, and the squeegee blade is preferably formed of silicone rubber, which is a flexible and elastic material.

The above object also includes preparing a photomask in which chromium (Cr) is patterned into a micropattern on a glass substrate; applying a photoresist to an upper portion of the glass substrate on which the photomask is formed; selectively exposing the photoresist to light by irradiating a lower portion of the glass substrate with UV light; putting the exposed glass substrate into a developing solution so that the photoresist transfers the pattern on the photomask; manufacturing a silicon mold by pouring silicon into the glass substrate using the glass substrate as a base; It is also achieved by a method for manufacturing a squeegee blade for conductive paste printing comprising the step of injecting silicone rubber into the silicone mold and then curing it to obtain a squeegee blade having a micropattern formed thereon.

Here, the plurality of micropatterns are uniformly arranged in the horizontal direction and stacking direction, and the micropatterns disposed on the top and bottom of one micropattern are arranged on the top and bottom so that the micropattern and the corresponding micropattern are misaligned in width. It is preferable that the micropattern or the micropattern is an oblique micropattern in which a plurality of micropatterns are regularly arranged obliquely so as to form an angle of 30 to 60°.

Alternatively, a plurality of the micropatterns are regularly arranged in the horizontal direction and stacking direction, and the micropatterns disposed on the top and bottom of one micropattern are arranged on the top and bottom so that the micropattern and the corresponding micropattern are misaligned in width. micropattern; A plurality of slanted micropatterns are regularly arranged at an angle of 30 to 60°, and the horizontal micropattern and the slanted micropattern form a single unit pattern and are repeatedly formed along the longitudinal direction of the squeegee blade. desirable.

In addition, the micropattern preferably has a protrusion protruding from the squeegee blade in a height of 20 to 50 μm.

According to the configuration of the present invention described above, the fillability of the conductive paste in the trench can be increased by forming the micropattern on the blade of the flexible printing squeegee.

In addition, by forming a micro-pattern on the blade, an effect of squeezing several times with one squeezing can be obtained, and a separate pressure can be applied to the squeezed conductive paste by being made of a flexible elastic material.

1 is a cross-sectional view of a squeegee blade for conductive paste printing according to an embodiment of the present invention;
2 is a flow chart of a method for manufacturing a squeegee blade;
3 is a front view showing a micropattern of a squeegee blade.

Hereinafter, a squeegee blade for conductive paste printing and a manufacturing method thereof according to an embodiment of the present invention will be described in detail with reference to drawings.

As shown in FIG. 1, the squeegee blade of the present invention is one of the components of the squeegee 100 formed by coupling the squeegee blade 130 to the squeegee holder 110. That is, the squeegee blade 130 has one end coupled to the squeegee holder 110 and the other end protruding from the squeegee holder 110, and the trench of the printed circuit board 30 in a state in which the conductive paste 10 is supplied to the traveling direction side By moving along (31), the conductive paste (10) is printed. Here, in the squeegee blade 130 , a micropattern 131 is formed in a protrusion shape on one or both sides of the blade 130 in contact with the trench 31 . The squeegee blade 130 of the present invention is manufactured using silicon rubber having excellent flexibility and elasticity in order to increase the fillability of the conductive paste 10 in the entire area of the trench 31, and the micropattern ( 131), a photolithography process was performed for implementation. The sequence of the method of manufacturing the squeegee blade 130 is as follows.

As shown in FIG. 2, first, a photomask in which chromium (Cr) is patterned on a glass substrate is manufactured and prepared. That is, in order to implement a desired design, a photomask patterned with a micropattern through etching of chrome is prepared. A glass substrate on which photolithography is performed refers to a glass substrate on which chromium having good adhesion is deposited.

Then, a step of applying a photoresist to the top of the glass substrate is performed. As a method of applying the photoresist to the glass substrate, a photoresist mixed with a solvent is applied to the top of the glass substrate by spray coating or spin coating in a range of 10 to 10 It is applied to have a thickness of 100 μm. After applying such a photoresist, the solvent is evaporated by heat drying on a hot plate at a temperature of 100 to 150 ° C for about 10 minutes. Here, the photosensitizer can be used by selecting a negative photosensitizer or a positive photosensitizer according to a desired pattern, and among them, THB 165P is most preferably used, but is not limited thereto.

After the prepared chrome photomask and the photoresist-coated glass substrate are brought into close contact with each other, an exposure step of irradiating UV light to a lower portion of the glass substrate is performed. UV light is preferably irradiated with an exposure amount of 80 to 140 mJ/cm 2 . When the exposure amount is less than 80 mJ/cm 2 , the exposure is not performed properly, and when the exposure amount exceeds 140 mJ/cm 2 , there is a problem that not only distortion of the pattern size occurs but also the accuracy of the pattern is lowered. After such an exposure step, a heat drying step by exposing the glass substrate to a hot plate at 90° C. may be further performed.

Next, the glass substrate exposed through UV light irradiation is put into a developing solution so that the photoresist transfers the design on the photomask. In the step of transferring through development, only the exposed portion of the exposed photosensitizer is dissolved in the developing solution, so that only the dissolved photosensitizer is peeled off and removed. Thereafter, the glass substrate may be additionally heat-treated so that the solvent does not remain on the upper portion of the glass substrate, but may be dried.

A silicon mold is manufactured by pouring silicon on the glass substrate using the glass substrate on which the pattern is implemented through the photomask and photoresist as a base. When silicon is injected into the glass substrate, silicon is injected between the patterns to form a pattern contrasting with the pattern of the glass substrate on the silicon mold.

After injecting silicone rubber, which is more flexible and elastic than the silicone mold, into the silicone mold made in this way, it is naturally cured at room temperature for about 24 hours. The pattern formed on the silicone mold is a pattern that contrasts with the pattern of the glass substrate, and the silicone rubber injected into the silicone mold is similarly formed in a pattern contrasting with the silicon mold, that is, the same pattern as the glass substrate. Here, Shinetsu-KE-17 corresponding to Hardness Durometer (50A), Tensile strength (2.0MPa), Elongation at break (140%), and Tear strength (3kN/m) was used as silicone rubber, but the type of silicone rubber is limited to these. It is possible to use one having various hardness and elastic modulus without being

In this way, when the cured silicone rubber is removed from the mold, a silicone rubber squeegee blade 130 having a micropattern 131 formed on the surface is manufactured, and it can be applied to the squeegee 100. In the case of the micropattern 131, the following various patterns can be applied.

In the case of the squeegee blade 130, the height is approximately 10 cm, and the portion touching the trench 31 of the printed circuit board 30 is approximately 3 cm. The micropattern 131 is formed on the squeegee blade 130, and in the case of the micropattern 131, unit patterns of about 1 mm are repeatedly formed in a stacked manner along the longitudinal direction of the squeegee blade 130. That is, about 100 unit patterns form a stacked shape at a height of about 10 cm, which is the height of the squeegee blade 130. In addition, the formed micropattern 131 protrudes in a direction perpendicular to the height of the squeegee blade 130, and the height of the protrusion of the protruding pattern is preferably 20 to 50 μm. When the height of the protrusion is less than 20 μm, the conductive paste 10 cannot be evenly filled between the trenches 31, so that the formation effect of the micropattern 131 cannot be properly obtained. It can be separated from the squeegee blade 130.

3A shows a squeegee blade on which micropatterns are formed horizontally, and a plurality of micropatterns having a height of about 50 μm and a width of about 200 μm are uniformly arranged in the horizontal and stacking directions. In addition, the micropattern disposed above and below one micropattern is formed so that the micropattern disposed above and below the corresponding micropattern is offset in width so that the horizontal micropattern can evenly contact and fill the conductive paste.

Similarly, FIG. 3B shows a squeegee blade on which micropatterns are formed horizontally, but the size of the micropattern is different from that of FIG. 3a. That is, FIG. 3B is a horizontal micropattern formed with a height of about 100 μm and a width of about 1 to 2mm. Compared to the micropattern of FIG. it was formed

3C shows a squeegee blade on which a plurality of micropatterns are formed in a diagonal line, and one diagonal micropattern is formed to have a height of about 50 μm and a width of 300 μm. Oblique micropatterns of this size are arranged at an angle of 30 to 60°, and a more preferable angle is 45°. In the case of a printed circuit board trench, it is formed in various patterns. In particular, it is not easy to fill an empty space with conductive paste because there are four corners in a region formed with a '+' character. However, when using a squeegee blade in which micropatterns are formed diagonally as shown in FIG. 3C, the conductive paste can be carefully filled even near the corner formed by the '+' character, so the conductive paste can be easily applied even to a printed circuit board that does not have flexibility. do. Here, when the angle of the oblique micropattern is less than 30° and exceeds 60°, the trench fillability cannot be increased because the micropattern becomes closer in the horizontal and vertical directions.

FIG. 3D is a view showing a squeegee blade formed with micropatterns in which the horizontal micropatterns arranged horizontally in FIG. 3B and the slanted micropatterns arranged diagonally in FIG. 3C are mixed. Among the micropatterns composed of unit patterns with a height of about 1 mm, oblique micropatterns composed of oblique lines are formed in the lower 2/3 area, and horizontal micropatterns arranged horizontally are formed in the upper 1/3 area. That is, the horizontal micropattern and the diagonal micropattern form one unit pattern and are repeatedly formed along the longitudinal direction of the squeegee blade. This squeegee blade can take advantage of both the advantages of the diagonal micropattern and the horizontal micropattern, and since it is arranged in two directions, the conductive paste can be evenly injected into all areas regardless of the pattern in which the trench is formed. can

In this micropattern, it is also preferable that the height of the protrusion protruding from the squeegee blade is 20 to 50 μm. In addition, the squeegee blade is made of silicone rubber, which is a flexible and elastic material. When the squeegee blade is made of a flexible and elastic material, the conductive paste is applied in a shape that swells to the top of the trench due to the elasticity of the silicone rubber during the application of the conductive paste. may be pressed into the trench so that the inside of the trench is also carefully filled with the conductive paste. In particular, when forming a squeegee blade with silicone rubber, pressure can be applied naturally, so that it can be supported only by the tension of the film during the roll-to-roll process later, which has the advantage of being highly effective in securing mass production.

Conventionally, the conductive paste is screen-printed using a squeegee blade whose shape does not change, but when applied to an inflexible printed circuit board, the conductive paste does not meticulously fill the trench. In particular, in the case of a trench having a '+' shape, it is more difficult to fill the conductive paste. Therefore, in the present invention, the filling ability of the conductive paste in the trench can be increased by forming the micropattern on the blade of the flexible printing squeegee. In addition, by forming a micro-pattern on the blade, it is possible to obtain the effect of squeezing several times with one squeezing, and since it is made of a flexible elastic material, it is possible to apply a separate pressure to the squeezed conductive paste. .

10: conductive paste
30: printed circuit board
31: trench
100: squeegee
110: squeegee holder
130: squeegee blade
131: micropattern

Claims (11)

One end is coupled to the squeegee holder and the other end protrudes from the squeegee holder, and the squeegee blade for conductive paste printing prints the conductive paste by moving along the trench of the printed circuit board in a state in which the conductive paste is supplied to the traveling direction side. in
A micropattern is formed in a protrusion shape on one or both surfaces of the blade in contact with the trench,
The plurality of micropatterns are regularly arranged in the horizontal and stacking directions, and the micropatterns disposed on the top and bottom of one micropattern are arranged on the top and bottom so that the micropattern and the corresponding micropattern are misaligned in width. Squeegee blade for conductive paste printing, characterized in that. delete One end is coupled to the squeegee holder and the other end protrudes from the squeegee holder, and the squeegee blade for conductive paste printing prints the conductive paste by moving along the trench of the printed circuit board in a state in which the conductive paste is supplied to the traveling direction side. in
A micropattern is formed in a protrusion shape on one or both surfaces of the blade in contact with the trench,
The micropattern is a squeegee blade for conductive paste printing, characterized in that the plurality of slanted micropatterns are regularly arranged obliquely to form an angle of 30 to 60 °. One end is coupled to the squeegee holder and the other end protrudes from the squeegee holder, and the squeegee blade for conductive paste printing prints the conductive paste by moving along the trench of the printed circuit board in a state in which the conductive paste is supplied to the traveling direction side. in
A micropattern is formed in a protrusion shape on one or both surfaces of the blade in contact with the trench,
The micropattern,
A plurality of horizontal micropatterns are uniformly arranged in the horizontal direction and stacking direction, and the micropatterns arranged on the top and bottom of one micropattern are arranged on the top and bottom so that the micropattern is misaligned in width with the corresponding micropattern;
It includes a plurality of oblique micropatterns that are regularly arranged obliquely to form an angle of 30 to 60 °,
Squeegee blade for conductive paste printing, characterized in that the horizontal micropattern and the diagonal micropattern form one unit pattern and are repeatedly formed along the longitudinal direction of the squeegee blade. delete delete In the method of manufacturing a squeegee blade for conductive paste printing,
preparing a photomask patterned with chromium (Cr) in a micropattern on a glass substrate;
applying a photoresist to an upper portion of the glass substrate on which the photomask is formed;
selectively exposing the photoresist to light by irradiating a lower portion of the glass substrate with UV light;
putting the exposed glass substrate into a developing solution so that the photoresist transfers the pattern on the photomask;
manufacturing a silicon mold by pouring silicon into the glass substrate using the glass substrate as a base;
A method of manufacturing a squeegee blade for conductive paste printing, characterized in that it comprises the step of injecting silicone rubber into the silicone mold and then curing it to obtain a squeegee blade on which a micropattern is formed. According to claim 7,
The plurality of micropatterns are regularly arranged in the horizontal and stacking directions, and the micropatterns disposed on the top and bottom of one micropattern are arranged on the top and bottom so that the micropattern and the corresponding micropattern are misaligned in width. Method for manufacturing a squeegee blade for conductive paste printing, characterized in that. According to claim 7,
The method of manufacturing a squeegee blade for conductive paste printing, characterized in that the plurality of micropatterns are diagonal micropatterns that are regularly arranged obliquely so as to form an angle of 30 to 60 °. According to claim 7,
The micropattern,
A plurality of horizontal micropatterns are uniformly arranged in the horizontal direction and stacking direction, and the micropatterns arranged on the top and bottom of one micropattern are arranged on the top and bottom so that the micropattern is misaligned in width with the corresponding micropattern;
It includes a plurality of oblique micropatterns that are regularly arranged obliquely to form an angle of 30 to 60 °,
Squeegee blade manufacturing method for conductive paste printing, characterized in that the horizontal micropattern and the diagonal micropattern form one unit pattern and are repeatedly formed along the longitudinal direction of the squeegee blade. According to claim 7,
The micropattern is a squeegee blade manufacturing method for conductive paste printing, characterized in that the height of the protrusion protruding from the squeegee blade is made of 20 to 50㎛.

Images