KR100855822B1 - Apparatus and Method of Printing the Pattern on the Substrate - Google Patents

Abstract

The present invention relates to a substrate printing apparatus and method capable of improving the reliability of a printed circuit board by improving the printing uniformity regardless of the warpage or shrinkage of the printed circuit board generated during a plurality of heat treatment processes.

Printed Circuit Board, Mask, Alignment, Recognition Mark

Description

Substrate printing apparatus and method {Apparatus and Method of Printing the Pattern on the Substrate}

BRIEF DESCRIPTION OF THE DRAWINGS The figure for demonstrating schematically the printing process of a typical solder paste.

Figure 2 is a side view schematically showing the configuration of a substrate printing apparatus according to an embodiment of the present invention.

3 is a diagram illustrating the printed circuit board and the metal mask shown in FIG.

4 is a view schematically showing a substrate printing method according to an embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

2: printed circuit board 2a, 4a: recognition mark

4: metal mask 6: vacuum suction table

8: main table 10: camera

12: jig frame 14: roller

16 mesh 18 control means

20: opening 24: circuit pattern

26, 36: circuit area 28, 38: dummy area

34: pattern hole

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate printing apparatus and method, and more particularly, to a substrate printing apparatus and method capable of improving the reliability of a printed circuit board by improving printing uniformity regardless of bending or shrinkage of a printed circuit board generated during a plurality of heat treatment processes. It is about.

In general, a printed circuit board (PCB) serves to easily connect various electronic devices according to a predetermined frame, and is widely used in all electronic products from home appliances to high-tech communication devices including digital TVs. As components, they are also classified into general-purpose PCBs, module PCBs, and package PCBs, depending on the purpose.

In other words, the printed circuit board is formed by attaching a thin plate such as copper to one side of a phenolic resin insulating plate or an epoxy resin insulating plate, and then etching it according to the wiring pattern of the circuit (corroding and removing only the circuit on the line) to form a necessary circuit. They are formed by drilling holes for attaching them.They are classified into single-sided boards, double-sided boards, and multi-layered boards according to the number of wiring circuits.The higher the number of layers, the better the mounting force of the parts, and they are adopted in high-precision products. With the development of the industry, ultra-thin printed circuit boards (thickness of 0.04 mm to 0.2 mm) are widely used.

Such a printed circuit board has a cross-section used for a relatively simple electronic device, but recently, a double-sided board having a circuit formed on both sides and interconnected through a through hole, or a multilayer in which it is expanded into a plurality of layers as well as both sides. Substrates are increasingly used.

Looking at the manufacturing method of a conventional substrate briefly, using a cladding disk coated with a copper foil having a thickness of μm on an insulating substrate, the pre-treatment step, the through-hole processing step, the electroless plating step, Circuit printing step, etching step and post-treatment step. Here, the pretreatment step is to prepare a full-scale PCB manufacturing process by cutting the cladding disc, to form a through hole using a drill in the cladding disc cut to the appropriate size in the pretreatment step and then formed in the step by electroless plating A thin film of copper foil is formed on the through-hole surface to enable later electrocopper plating.

Subsequently, in the circuit printing step, a photosensitive film is coated on the cladding plate, followed by exposure and development to mask the remaining portions except the copper circuit portion and the through hole portion of the predesigned wiring diagram, and then form solder plating or nickel and gold plating thereon. To form a protective film to protect the copper foil of the circuit portion, and then, in the etching step, the photosensitive film masking is peeled off, and the copper foil of the non-circuit portion is etched to leave only the circuit wiring portion, and the solder plating is peeled off when solder plating is applied. . In the post-treatment step, the substrate is manufactured through intermediate inspection, external processing, and final inspection.

Meanwhile, a solder paste in a molten state is applied to the printed circuit board in a predetermined pattern so that various types of small electronic components such as semiconductor chips or resistance chips can be mounted on the surface. Here, the method of applying the solder paste is screen printing, which directly prints the solder paste pattern using plate making, and a roller coating in which a relatively low viscosity solder paste is applied to a roller made of rubber and coated on a circuit board. And, by using a solder paste having a lower viscosity than that used in the roller coating method, the curtain paste (Curtain Coating) to export the solder paste through the slit to form a curtain-type film and to pass it through the circuit board (Curtain Coating), There is a spray coating for spray coating solder paste to form a coating film on a circuit board.

A screen printer is widely used in the method of applying the solder paste, and this screen printer is performed by a solder paste coating apparatus. The screen printer compresses the solder paste supplied on a metal mask in which a specific pattern of openings are formed, using a squeegee blade, and applies the solder paste to the component mounting surface of the printed circuit board.

1 is a view schematically showing a printing process of a solder paste that is generally widely performed.

As shown in FIG. 1, a vacuum suction table 200 of a plate for vacuum suction of the printed circuit board 150 is provided on the upper surface of the plate-shaped base table 100, and the outer side of the vacuum suction table 200 is located above. A mask frame 300 having a jig 310 supporting the metal mask 350 is provided while protruding upward compared to the vacuum suction table 200.

Hereinafter, briefly describing the printing process, the printed circuit board 150 is placed on the upper surface of the vacuum suction table 200, and the metal mask 350 supported by the jig 310 is placed on the upper surface of the vacuum adsorption table 200, and then these printed circuit boards are placed. The 150 and the metal mask 350 are aligned with each other.

Subsequently, the solder paste 500 is pushed into the pattern hole 360 of the metal mask 350 using a squeegee 400 on one side of the upper surface of the metal mask 350 to perform printing, and then the printing is completed. When the printed circuit board 150 and the metal mask 350 is separated from each other.

On the other hand, in order to obtain a precise print quality, it is necessary to satisfy the optimized printing conditions, for this purpose, the application condition of the solder paste 500 and the design of the metal mask 350, as well as between the printed circuit board 150 and the metal mask 350 It depends on ensuring mutual alignment.

In particular, in recent years, printed circuit boards have been increasingly applied to flip chips that form bumps using solder paste and connect devices thereon, as well as to a large area of printed circuit boards. As a result of the deformation caused by the stretching ratio, the matching between the printed circuit board and the mask is poor.

In other words, the printed circuit board that requires the latest precision printing has a pitch of less than 120㎛, and the printed circuit board has pads of about 60㎛ for printing solder paste, and the metal mask is about 20 times the size of the pad. The opening is about large in size, i.e., in size of 80 mu m.

On the other hand, the conventional substrate and the metal mask is matched by hand using a recognition mark formed on the substrate and the metal mask prior to the solder paste coating operation, wherein the size of the printed circuit board compared to the size of the metal mask Even if it is large or small, the print quality is drastically deteriorated.

In other words, since the printed circuit board undergoes numerous heat treatment processes until the solder paste printing process, stretching occurs due to shrinkage of the organic material, and thus the pattern matching between the substrate and the metal mask does not match.

Accordingly, in the case of forming a bump by melting the solder paste, a missing bump or a small bump is formed because the terminal formed on the printed circuit board and the solder do not sufficiently react and weld, and a sufficient amount of the solder paste is not printed. Etc. are generated to reduce the print quality to provide a cause of product defects, as well as to significantly reduce the reliability of the product (electronic device) employing the same.

Accordingly, an object of the present invention is to provide a substrate printing apparatus and method capable of improving the reliability of a printed circuit board by improving the printing uniformity regardless of the warpage or shrinkage of the printed circuit board generated during a plurality of heat treatment processes.

In order to achieve the above object, a substrate printing apparatus according to an exemplary embodiment of the present invention includes a circuit region in which a circuit pattern is to be formed and a dummy region formed at an outer side of the circuit region, and a printed circuit board on which the first recognition mark is formed. Vacuum suction table for fixing the printed circuit board by vacuum suction; A circuit region disposed on an upper surface of the printed circuit board, having an elastic force capable of being stretched or retracted to a predetermined length, and having a pattern hole for forming a circuit pattern in a circuit region of the printed circuit board; and a dummy region formed outside the circuit region A metal mask including a second recognition mark formed in the dummy area; A jig frame for supporting the metal mask and having rollers for adjusting the top / bottom and left / right sizes of the metal mask through a mesh formed outside the slope of the metal mask; And control means for determining whether the first recognition mark and the second recognition mark are aligned and controlling the movement of the roller according to the alignment.

A substrate printing method according to an embodiment of the present invention comprises the steps of: a) adsorbing a printed circuit board on which a circuit region in which a circuit pattern is to be formed and a dummy region formed outside the circuit region to a vacuum suction table; b) placing a metal mask on the printed circuit board, wherein a pattern hole is formed in a circuit region corresponding to the circuit pattern and a dummy region is formed outside the circuit region; c) detecting the position of the printed circuit board and the metal mask to determine whether the printed circuit board and the metal mask match the position coordinates; d) If the position coordinates of the printed circuit board and the metal mask do not match, the metal mask is stretched or shrunk in a left / right direction and an up / down direction to adjust the size of the metal mask and the printed circuit board. Matching the position coordinates of the metal mask; And e) applying the solder paste to the printed circuit board by bringing the metal mask into close contact with the printed circuit board.

A substrate printing method according to another embodiment of the present invention includes the steps of: a) adsorbing a printed circuit board on which a circuit region in which a circuit pattern is to be formed and a dummy region formed outside the circuit region to a vacuum suction table; b) placing a metal mask on the printed circuit board, wherein a pattern hole is formed in a circuit region corresponding to the circuit pattern and a dummy region is formed outside the circuit region; c) detecting the position of the printed circuit board and the metal mask to determine whether the printed circuit board and the metal mask match the position coordinates; d) when the position coordinates of the printed circuit board and the metal mask do not match, the metal mask is stretched or shrunk in a left / right direction or an up / down direction to adjust the size of the metal mask so that the printed circuit board and the metal mask are adjusted. Matching the position coordinates of the metal mask; And e) applying the solder paste to the printed circuit board by bringing the metal mask into close contact with the printed circuit board.

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

2 is a side view schematically illustrating a configuration of a substrate printing apparatus according to an exemplary embodiment of the present invention, and FIG. 3 is a diagram illustrating a printed circuit board and a metal mask shown in FIG. 2.

2 and 3, a substrate printing apparatus according to an embodiment of the present invention includes a vacuum suction table 6 and a vacuum suction table fixing the printed circuit board 2 by vacuum sucking the printed circuit board 2. 6) Supporting the main table (8), located on the upper surface of the printed circuit board 2, a pattern hole 34 for forming a pattern in the printed circuit board 2 is formed, which can be stretched or shrunk to a predetermined length A roller for supporting the metal mask 4 and the metal mask 4 having tensile force, and adjusting the size of the metal mask 4 through a mesh 16 formed on the outer surface of the metal mask 4 ( The jig frame 12 having the 14, the printed circuit board 2 and the metal mask (4) is provided between the first recognition mark (2a) formed on the printed circuit board 2 and formed on the metal mask (4) Camera 10 for capturing second recognition mark 4a and first recognition mark 2a and second recognition mark taken by camera 10 And control means 18 for matching the printed circuit board 2 and the metal mask 4 by tensioning or contracting the metal mask 4 through the roller 14 based on the position coordinates of (4a).

In addition, the substrate printing apparatus according to the embodiment of the present invention includes an opening 20 for carrying in or taking out a printed circuit board.

The vacuum suction table 6 fixes the printed circuit board 2 carried in the opening 20 using a vacuum. The vacuum suction table 6 is provided on the main table 8. The printed circuit board 2 seated on the vacuum suction table 6 includes a circuit region 26 in which a circuit pattern is to be formed and a dummy region 28 formed outside the circuit region 26. At 28, a first recognition mark 2a capable of detecting the position of the printed circuit board 2 is formed.

The metal mask 4 is formed of a nickel (Ni) material having a tensile force that can be stretched or shrunk to a predetermined length, is installed on the upper surface of the printed circuit board 2, and has a pattern in the form of a pattern to be formed on the printed circuit board 2. Holes 34 are formed.

The metal mask 4 includes a circuit region 36 in which the pattern hole 34 is formed and a dummy region 38 formed outside the circuit region 36, and the position of the metal mask 4 is located in the dummy region. A second recognition mark 4a for recognition is formed.

In addition, the outer surface of the metal mask 4, the mesh 16 is formed of a polyester material, the metal mask 4 and the mesh 16 is bonded to each other.

The jig frame 12 serves to support the metal mask 4, and a roller 14 is installed therein to adjust the size of the metal mask 4.

In other words, the rollers 14 respectively coupled to the meshes 16 formed on the periphery (up / down and left / right) of the metal mask 4 may be meshed according to a control signal supplied from the control means 18. The size of the metal mask 4 is adjusted by stretching or contracting the metal mask 4 in the X-axis (left / right) and Y-axis (up / down) while winding or unwinding.

The camera 10 is installed between the printed circuit board 2 and the metal mask 4 to form a first recognition mark 2a formed on the printed circuit board 2 and a second recognition mark 4a formed on the metal mask 4. ).

The camera 10 simultaneously photographs a plurality of first recognition marks 2a and second recognition marks 4a formed on the printed circuit board 2 and the metal mask 4 located at the bottom thereof, or a plurality of cameras 10 are installed. According to the position coordinates from the control means 18, the first recognition mark 2a and the second recognition mark 4a formed on the printed circuit board 2 and the metal mask 4 can be photographed separately.

At this time, the position data photographed by the camera 10 is transmitted to the control means 18.

The control means 18 controls the movement and photographing of the camera 10, controls the movement of the metal mask 4, and controls the movement of the roller 14 based on the position data supplied from the camera 10. .

That is, the control means 18 moves the camera 10 to photograph the first recognition mark 2a and the second recognition mark 4a formed on the printed circuit board 2 and the metal mask 4, and the camera ( The positional data photographed from 10 may be supplied to detect the position coordinates of the first recognition mark 2a and the second recognition mark 4a respectively formed on the printed circuit board 2 and the metal mask 4.

Thereafter, the control means 18 determines the degree of distortion of the printed circuit board 2 and the metal mask 4 according to the detected position coordinates.

At this time, when the first recognition mark 2a and the second recognition mark 4a coincide, that is, when the first recognition mark 2a and the second recognition mark 4a are aligned, the control means 18 is a printed circuit. The metal mask 4 is lowered to closely adhere to the substrate 2, and then the printed circuit board 2 is formed through a pattern hole 34 formed in the metal mask 4 using a squeegee (not shown). ) Apply solder paste.

However, when the first recognition mark 2a and the second recognition mark 4a do not coincide with each other, the control means 18 controls the rollers according to the degree of distortion of the first recognition mark 2a and the second recognition mark 4a. The control signal for rotating the 14 is supplied to the roller 14.

As a result, the roller 14 is rotated so that the metal mask 4 is stretched or shrunk in the X-axis direction (left / right direction) and / or Y-axis direction (up / down direction). In other words, the size of the metal mask 4 is adjusted.

In the substrate printing apparatus according to the exemplary embodiment of the present invention, the first recognition mark 2a and the second recognition formed on the dummy regions 28 and 38 of the printed circuit board 2 and the metal mask 4 are formed by the camera 10. Although only the mark 4a is described as being photographed, the camera 10 prints not only the first recognition mark 2a and the second recognition mark 4a formed in the dummy region of the printed circuit board 2 and the metal mask 4 but also the printing. The circuit patterns 24 and the pattern holes 34 formed in the circuit regions 26 and 36 of the circuit board 2 and the metal mask 4 may be photographed.

Accordingly, the control means 18 has rollers 14 according to the position coordinates of the circuit patterns 24 and the pattern holes 34 formed in the circuit regions 26 and 36 of the printed circuit board 2 and the metal mask 4. ), The metal mask 4 may be stretched or shrunk in the X-axis direction (left / right direction) and / or Y-axis direction (up / down direction).

The control means 18 controls the metal mask 4 according to the position coordinates of the circuit patterns 24 and the pattern holes 34 formed in the circuit areas 26 and 36 of the printed circuit board 2 and the metal mask 4. You can adjust the size.

The control means 18 receives only the position data of the first recognition mark 2a and the second recognition mark 4a from the camera 10 or the circuit area of the printed circuit board 2 and the metal mask 4. Only the position data of the circuit patterns 24 and the pattern holes 34 formed on the 26 and 36 may be supplied.

Further, the control means 18 is a circuit formed in the circuit area of the printed circuit board 2 and the metal mask 4 and the position data of the first recognition mark 2a and the second recognition mark 4a from the camera 10. The position data of the pattern and the pattern hole 34 may be simultaneously supplied.

A method of printing solder paste on a printed circuit board using the substrate printing apparatus having such a configuration will be described below with reference to FIG. 4.

At this time, the method for adjusting the size of the metal mask 4 by the position data of the first recognition mark 2a and the second recognition mark 4a and the circuit area 26 of the printed circuit board 2 and the metal mask 4. Since the method of adjusting the size of the metal mask 4 by the position data of the circuit pattern 24 and the pattern hole 34 formed in the 36 is the same, the control means 18 is here from the camera 10 to the printed circuit board 2. And only a method of printing solder paste on a printed circuit board by receiving only position data of the first recognition mark 2a and the second recognition mark 4a respectively formed in the dummy regions 28 and 38 of the metal mask 4. Let's do it.

First, the printed circuit board 2 is inserted into the substrate printing apparatus 1 through the opening 20 and fixed to the vacuum suction table 6 (S110).

Subsequently, when the metal mask 4 supported by the jig frame 12 is installed on the printed circuit board 2, the control means 18 is formed in the dummy regions of the printed circuit board 2 and the metal mask 4, respectively. The camera 10 is moved to photograph the first recognition mark 2a and the second recognition mark 4a.

At this time, the camera 10 controls the photographing position data after photographing the first recognition mark 2a and the second recognition mark 4a respectively formed on the printed circuit board 2 and the metal mask 4. (S120)

Accordingly, the control means 18 uses the position data supplied from the camera 10 to form the first recognition mark 2a and the second recognition mark 4a respectively formed on the printed circuit board 2 and the metal mask 4. The position coordinate of) is detected.

Thereafter, the control means 18 determines the degree of distortion of the printed circuit board 2 and the metal mask 4 according to the detected position coordinates (S140).

At this time, when the position coordinates of the first recognition mark 2a and the second recognition mark 4a coincide, that is, the control means 18 when the first recognition mark 2a and the second recognition mark 4a are aligned. The metal mask 4 is lowered so that the metal mask 4 is in close contact with the printed circuit board 2, and then the printed circuit is formed through a pattern hole 34 formed in the metal mask 4 using a squeegee (not shown). Solder paste is applied to the substrate 2 (S150).

However, if the positional coordinates of the first recognition mark 2a and the second recognition mark 4a do not coincide, the control means 18 may be adapted to the degree of distortion of the first recognition mark 2a and the second recognition mark 4a. Accordingly, a control signal for rotating the roller 14 is supplied to the roller 14.

As a result, the roller 14 is rotated so that the metal mask 4 is stretched or shrunk in the X-axis direction (left / right direction) and / or Y-axis direction (up / down direction). In other words, the size of the metal mask 4 is adjusted.

As a result, the position coordinates of the printed circuit board 2 and the metal mask 4 are aligned, that is, coincident with each other.

When the position coordinates of the printed circuit board 2 and the metal mask 4 coincide, the control means 18 makes the metal mask 4 adhere to the printed circuit board 2.

Thereafter, a solder paste is applied to the printed circuit board 2 using a squeegee (not shown).

As described above, the substrate printing apparatus and the printing method according to the embodiment of the present invention adjust the size of the metal mask 4 so that the printed circuit board 2 and the metal mask 4 are aligned so that many heat treatments are performed during the manufacturing process of the printed circuit board. Printing uniformity can be improved regardless of bending or shrinkage of the printed circuit board by the process, thereby improving reliability of the printed circuit board.

In addition, since the substrate printing apparatus and the printing method according to the embodiment of the present invention adjust the size of the metal mask 4 to align the printed circuit board 2 and the metal mask 4, the size is the same and the pattern hole 34 ) Can be applied to a printed circuit board using various metal masks having different shapes.

On the other hand, the present invention is not limited to the embodiments described, it is apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, such modifications or variations will have to belong to the claims of the present invention.

As described above, the present invention adjusts the size of the metal mask to align the printed circuit board and the metal mask to improve the printing uniformity irrespective of warpage or shrinkage of the printed circuit board due to many heat treatment processes during the printed circuit board manufacturing process. Can be.

Accordingly, the present invention can improve the reliability of the printed circuit board.

In addition, since the present invention adjusts the size of the metal mask to align the printed circuit board and the metal mask, the present invention can be applied to a printed circuit board using various metal masks having the same size and different shapes of pattern holes, thereby manufacturing a printed circuit board. Reduce costs

Claims (11)

A vacuum suction table including a circuit area where a circuit pattern is to be formed and a dummy area formed outside the circuit area, and vacuum adsorbing the printed circuit board having the first recognition mark formed on the dummy area to fix the printed circuit board; A circuit region disposed on an upper surface of the printed circuit board, having an elastic force capable of being stretched or retracted to a predetermined length, and having a pattern hole for forming a circuit pattern in a circuit region of the printed circuit board; and a dummy region formed outside the circuit region A metal mask including a second recognition mark formed in the dummy area; A jig frame for supporting the metal mask and having rollers for adjusting the top / bottom and left / right sizes of the metal mask through a mesh formed outside the slope of the metal mask; And And control means for determining whether the first recognition mark and the second recognition mark are aligned and controlling the movement of the roller according to the alignment. delete The method of claim 1, The control means rotates the roller when the first recognition mark and the second recognition mark do not coincide with each other to rotate the metal mask in an up / down direction, or left / right direction, or up / down direction and left / right direction. A substrate printing apparatus characterized in that the tension or shrinkage. The method of claim 1, And a camera for photographing the first recognition mark and the second recognition mark and supplying position data of the first recognition mark and the second recognition mark to the control means. The method of claim 4, wherein And the camera photographs the circuit pattern and the pattern hole and supplies position data to the control means. a) adsorbing a circuit region where a circuit pattern is to be formed and a printed circuit board having a dummy region formed outside the circuit region to a vacuum adsorption table; b) placing a metal mask on the printed circuit board, wherein a pattern hole is formed in a circuit region corresponding to the circuit pattern and a dummy region is formed outside the circuit region; c) detecting the position of the printed circuit board and the metal mask to determine whether the printed circuit board and the metal mask match the position coordinates; d) when the position coordinates of the printed circuit board and the metal mask do not match, the metal mask is stretched or shrunk in a left / right direction and an up / down direction to adjust the size of the metal mask to control the printed circuit board and the metal mask. Matching the position coordinates of the metal mask; And e) applying the solder paste to the printed circuit board by bringing the metal mask into close contact with the printed circuit board. The method of claim 6, The step c) may include detecting a position of a first recognition mark formed on a dummy area of the printed circuit board; Detecting a second recognition mark formed on a dummy region of the metal mask; And And comparing the position coordinates of the first recognition mark with the position coordinates of the second recognition mark. The method of claim 6, C) detecting the position of the circuit pattern; Detecting a position of the pattern hole; And And comparing the position coordinates of the circuit pattern with the position coordinates of the pattern hole. a) adsorbing a circuit region where a circuit pattern is to be formed and a printed circuit board having a dummy region formed outside the circuit region to a vacuum adsorption table; b) placing a metal mask on the printed circuit board, wherein a pattern hole is formed in a circuit region corresponding to the circuit pattern and a dummy region is formed outside the circuit region; c) detecting the position of the printed circuit board and the metal mask to determine whether the printed circuit board and the metal mask match the position coordinates; d) when the position coordinates of the printed circuit board and the metal mask do not match, the metal mask is stretched or shrunk in a left / right direction or an up / down direction to adjust the size of the metal mask so that the printed circuit board and the metal mask are adjusted. Matching the position coordinates of the metal mask; And e) applying the solder paste to the printed circuit board by bringing the metal mask into close contact with the printed circuit board. The method of claim 9, The step c) may include detecting a position of a first recognition mark formed on a dummy area of the printed circuit board; Detecting a second recognition mark formed on a dummy region of the metal mask; And And comparing the position coordinates of the first recognition mark with the position coordinates of the second recognition mark. The method of claim 9, C) detecting the position of the circuit pattern; Detecting a position of the pattern hole; And And comparing the position coordinates of the circuit pattern with the position coordinates of the pattern hole.

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