KR20040032836A - Screen printer - Google Patents

Abstract

PURPOSE: A screen printer is provided to prevent pollution of the work piece by arranging the adhesive between the work piece and the table, and to charge ink conveniently by forming the uneven part in the surface of the adhesive tape. CONSTITUTION: A work piece(50) with penetration holes(61) is stuck to an adhesive tape(65), and the adhesive tape is bonded to a table(70). A first squeegee(112) fills up the penetration hole of the work piece with ink, and a second squeegee(113) applies ink on the surface of the work piece. The work piece is fastened to the table by the adhesive tape, and the penetration hole is plugged by the adhesive tape to charge ink in the penetration hole efficiently. The printing pressure of the first squeegee is greater than the printing pressure of the second squeegee, and the first squeegee is placed opposite to the second squeegee. Printing on the moving passage is performed by the first squeegee, and printing on the return passage is performed by the second squeegee.

Description

Screen Printing Machine {SCREEN PRINTER}

The present invention relates to the printing of a workpiece having a through hole (through hole). In particular, it relates to printing on a thin substrate having a thickness of 0.2 mm or less as a substrate on which a BGA (ball grid array) or a CSP (chip size package) is mounted.

Fig. 13 is a perspective view showing a screen printing machine.

14 is a schematic side view of a screen printing machine.

15 is a schematic plan view of a screen printing machine.

In Fig. 13, reference numeral 101 is a screen printing machine, 102 is a base of a screen printing machine, 103 is a movable table attached to a movable body, 104 is a guide rail for guiding movement of the moving table, 105 is an operation box of a screen printing machine; Reference numeral 107 denotes an operation switch attached to the operation box, and 109 denotes a printing unit which performs screen printing on the workpiece placed on the moving table 103.

14 and 15, reference numeral 110 denotes a workpiece placed on the moving table 103, 200 is a screen plate, 201 is a screen frame of the screen plate 200, 211 is attached to the screen plate 200 The screen 106 is a slider for holding the skid 111 and a scraper (not shown) while simultaneously sliding in the radial direction of the through-holes of arrows A and D, 108 is a frame for sliding the slider 106. .

The moving table 103 is slidably attached left and right along the guide rail 104 attached to the base 102. When the movement table 103 moves to the lower portion of the printing unit 109, the movement table 103 is restrained by a stopper (not shown), and the printing unit 109 performs screen printing on the work piece 110.

A suction hole 190 is formed in the moving table 103, and as shown by the arrow, the work 110 is sucked into the moving table 103 by sucking air.

The moving table 103 of the conventional screen printing machine is provided with a suction hole 190 to suck the work 110. When the work 110 is made of a flexible material or thin, Fig. 16 As shown in the drawing, unevenness may occur on the surface of the work piece 110. As described above, when the surface of the workpiece 110 is uneven, there is a problem that printing is not performed correctly.

17, a through hole 191 may exist in the workpiece 110 in some cases. The through hole 191 is a hole penetrating from the surface of the work piece 110 to the back surface as shown in FIG. When printing is performed by matching the position of the through hole 191 with the position of the suction hole 190 of the movement table 103, the ink 199 is sucked from the suction hole 190 and the back surface of the work piece 110 is formed. There was a problem spotting.

When printing is performed to fill the through hole 191 by the ink 199, the ink 199 is sucked through the suction hole 190 so that the through hole 191 is drawn by the ink 199. The problem of not charging occurs.

FIG. 19 shows a case in which suction is actively used when the ink 199 is filled in the through hole 191 of the workpiece 110. The workpiece 110 is supported by a vinyl chloride plate 197 and a support column 196. The ink 199 is easily filled in the through hole 191 by sucking air as in the arrow.

FIG. 20 is a diagram showing a conventional screen printing method in the case of performing hole filling printing as shown in FIG.

First, hole fill printing as shown in FIG. 19 is performed. Next, the ink is dried. Next, the ink swelling out of the workpiece is polished to flatten the surface of the workpiece. Next, the first layer is printed on the surface of the workpiece and dried. Then, the second layer is printed on the surface of the work piece and dried. Next, the first layer is printed on the back surface and dried. Then, the second layer is printed on the back surface and dried.

As described above, in the conventional printing method, five times of drying must be performed. Alternatively, the filling from the hole filling printing to the polishing may be omitted, but even in this case, four drying operations should be performed.

When the thickness of the BGA substrate or the CSP substrate is 0.2 mm or less, the jig whose thickness is thin and the circumference of the lower portion of the through hole cannot be used. This is because the substrate is so thin that the through-hole portion is low and cannot be uniformly applied. In addition, since the substrate is thin, it is impossible to polish the substrate after hole filling printing.

The present invention has been made to solve the above problems, and an object of the present invention is to be able to load the workpiece flat on the surface of the table even when the workpiece is thin or the workpiece is easily bent.

The present invention also aims to ensure that the workpiece can be reliably adsorbed against the table even when a through hole is present in the workpiece, and that the printed ink does not fall through the through hole or contaminate the back surface of the workpiece. do.

Moreover, an object of this invention is to make it possible to reliably fill ink with respect to the through-hole of a workpiece | work.

1 is an exploded perspective view of main parts of the screen printing machine of the present invention.

2 is a view showing a printing state using a conventional adhesive tape.

3 is a view showing a printing state using the adhesive tape of the present invention.

4 is a diagram when peeling a conventional adhesive tape.

5 is a diagram when peeling off the adhesive tape of the present invention.

Figure 6 illustrates a screen printing method of the present invention.

Figure 7 shows a first printing process of the present invention.

8 shows a second printing process of the present invention.

9A and 9B show a loading and unloading method of the workpiece of the present invention.

10 is a view showing a peeling method of an adhesive tape of the present invention.

Figure 11 shows a Teflon processed film of the present invention.

Fig. 12 is a diagram showing the relationship between the adhesive tape of the present invention and the length of the workpiece.

Figure 13 is a perspective view of a conventional screen printing machine.

14 is a side view of a conventional screen printing machine.

Fig. 15 is a plan view of a conventional screen printing machine.

Figure 16 illustrates a problem of a conventional screen printing machine.

Figure 17 shows a work piece with a conventional through hole.

Fig. 18 shows a problem in printing on a work piece having a conventional through hole.

19 is a view for explaining hole filling using a conventional suction force.

20 shows a conventional screen printing method.

<Explanation of symbols for the main parts of the drawings>

31: conventional adhesive

33: film

34: conventional adhesive tape

35: adhesive

36: motor

50: workpiece

61: through hole

65: adhesive tape

66: adhesive roll

67: winding roll

70: table

71: suction hole

84 ink

86: circuit pattern

90: screen

92: screen frame

112: first ski resort

113: second ski slope

114: Teflon processed film

In the screen printing machine according to the present invention is a screen device for loading a workpiece having a through hole on a table and performing screen printing with ink,

A first skid for filling the through-hole of the workpiece with ink,

And a second skid for applying ink to the surface of the workpiece.

The angle formed by the first skid and the screen during screen printing of the first skid is smaller than the angle between the screen and the second skid when the screen is printed by the second skid.

The pressure at the time of screen printing of the first skid is greater than the pressure at the time of screen printing of the second skid.

The first skid and the second skid are opposed to each other, and the first skid and the second skid are attached to each other on the same side of the work piece by the first skid in the moving path, and by the second skid in the return road. .

<First Embodiment>

The present invention is preferred for application to screen printing of BGA substrates or CSP substrates. Current BGA substrates or CSP substrates have a thickness of 0.2 mm, but will be 0.1 mm or less in the near future. When the substrate (workpiece) has a thickness of 0.1 mm or less, the substrate itself becomes flexible and warp (distortion) of the substrate occurs, and it becomes difficult to reliably fix the substrate by a method using a jig for fixing a conventional workpiece. . Then, as a method of fixing this board | substrate to the table of a screen printing machine, it is a big characteristic of this invention to use the fixing method by an adhesive tape (adhesive film).

1 is a diagram showing an embodiment of the screen printing machine of the present invention.

The screen plate 99 is composed of a screen 90 and a screen frame 92. Moreover, this screen printing machine is equipped with the 1st ski slope 112 and the 2nd ski slope 113. As shown in FIG. The adhesive roll 66 and the winding roll 67 are provided in the both sides of the table 70. As shown in FIG. The adhesive tape 65 is attached so that the adhesion surface can move continuously from the adhesive roll 66 to the winding roll 67 upward. The back surface of the workpiece 50 is adhered to the adhesive tape 65. The workpiece 50 is provided with a through hole (through hole) 61. The table 70 can reciprocate in the directions of arrows B and C. FIG. In addition, the first skid 112 performs a printing operation in the direction of the arrow A (moving path). In addition, the second skid 113 performs a printing operation in the direction of the arrow D (return path). The adhesive roll 66 rotates in the direction of the arrow E to release the adhesive tape 65, and the adhesive tape 65 moves with the workpiece in the direction of the arrow F. As shown in FIG. The winding roll 67 rotates in the direction of an arrow G to wind up the adhesive tape 65. The width W1 of the work piece 50 is equal to the width W2 of the adhesive tape 65 (W1 = W2).

Next, with reference to Figs. 2 and 3, the conventional adhesive tape 34 and the adhesive tape 65 of the present invention will be described.

The conventional adhesive tape 34 shown in FIG. 2 is composed of a conventional adhesive 31 and a film 33. When printing using the conventional adhesive tape 34, since the lower periphery of the through hole 61 is covered with the conventional adhesive 31, the place where the air in the through hole 61 escapes none. For this reason, when the ink 84 is filled from above, the air pressure may hinder the filling of the ink 84, so that the ink 84 may not sufficiently flow into the through hole 61.

On the other hand, as shown in FIG. 3, the adhesive tape 65 of this invention uses the film 33 as a support base material, and forms the uneven part in the adhesive 35. As shown in FIG. Due to the presence of the uneven portion, air in the through hole 61 can flow into the concave portion of the pressure-sensitive adhesive 35 so as not to prevent the inflow of the ink 84 into the through hole 61.

On the other hand, the gap formed in the concave portion of the pressure-sensitive adhesive 35 is not a gap large enough to flow in the viscous liquid ink 84. That is, the uneven part formed in the adhesive 35 is uneven | corrugated for escaping air (or gas), and does not generate the gap | interval enough to introduce the ink 84 (or liquid).

Next, the difference between the conventional adhesive tape 34 and the adhesive tape 65 of the present invention will be described again with reference to FIGS. 4 and 5.

As shown in FIG. 4, the conventional adhesive 31 of the conventional adhesive tape 34 contains the composition melt | dissolved by the solvent of the ink 84 (including the thinner, a diluent, and a mixed solvent). . Therefore, when peeling the conventional adhesive tape 34 from the workpiece | work 50, there exists a possibility that the conventional adhesive 31 may melt | dissolve and remain in the workpiece | work 50 and the circuit pattern 86. FIG. And when the adhesive force of the conventional adhesive 31 is too strong, there exists a possibility that the ink 84 (or ink 84 printed on the surface of the workpiece | work 50) filled in the through-hole 61 may be peeled off. .

On the other hand, as shown in FIG. 5, the adhesive tape 65 of this invention uses the adhesive 35 comprised only from the component which does not melt | dissolve by the solvent of the ink 84. As shown in FIG. Therefore, when peeling the adhesive tape 65 from the workpiece | work 50, the adhesive 35 does not remain in the workpiece | work 50. FIG. Moreover, since the uneven part exists in the surface of the adhesive 35, it can peel easily from the workpiece | work 50 and the circuit pattern 86, and the ink 84 (or the workpiece | work 50) filled in the through hole 61 is carried out. There is little possibility that the ink 84 printed on the surface of the peeling off may be peeled off.

As mentioned above, using the adhesive tape 65 of this invention has the following advantages.

(1) The plurality of things which changed the adhesive force of the adhesive tape 65 are prepared, and the optimal adhesive tape 65 can be used according to the thickness of the workpiece | work 50, the viscosity of the ink 84, etc. That is, control of adhesive force is easy.

(2) By forming the uneven portion on the surface of the pressure sensitive adhesive 35 of the pressure sensitive adhesive tape 65, the air easily flows and the ink 84 is easily filled. In addition, since the adhesive tape 65 is generally flat, there is no inflow of ink to the back surface of the work piece. That is, the through hole 61 is blocked by the adhesive tape 65, and the back surface of the work is flattened so that the protrusion of the ink 84 to the back of the work is eliminated, so that the polishing operation for removing the protrusion is unnecessary.

(3) Compared with the case of using the conventional jig, the alignment of the jig and the work piece 50 is unnecessary, and the positioning operation becomes unnecessary. In other words, when the workpiece is mounted on the table (the jig), the pin guide portion and the image recognition device become unnecessary.

(4) Conventionally, in the case of performing hole filling printing only in a portion where a through hole exists, printing was performed using a screen of a hole filling pattern. However, in the present invention, since the back surface of the substrate is held flat by the adhesive tape 65, When hole filling printing is performed, patternless printing becomes good. The patternless means that the printing pattern of the whole surface is uniform without using any special pattern. Since it is printing by a non-pattern, the accurate positioning operation | movement to a table of a workpiece becomes unnecessary.

(5) In the case of double-sided printing, in case of printing the other side after printing on one side, the whole surface of one side after printing is covered with adhesive tape so that the surface of the printed work does not directly contact the table, thus preventing dirt from ink on the table. Can be tried.

(6) A suction hole formed in the table can be used as before. That is, the entire surface of the adhesive tape 65 is attracted to the table by suction from the suction hole of the table, and the entire surface of the workpiece 50 is adsorbed by the adhesive 35 of the adhesive tape 65 as a result. 50) is fixed to the table all over.

(7) Moreover, since the workpiece | work 50 is affixed with the adhesive tape 65, plate separation becomes favorable when peeling off the screen 90 from the workpiece | work 50 after printing. When the screen 90 and the work 50 are removed by lifting the screen 90 after printing or by lowering the table 70 after printing, the work 50 is adhered by the adhesive tape 65. Therefore, the work 50 can be prevented from sticking to the screen 90. That is, there exists an advantage that plate space | interval becomes favorable. In particular, in the case where the work 50 is a thin substrate having a thickness of 0.1 mm or less, there is a possibility that the end of the work 50 sticks to the screen 90, but the adhesion by the adhesive tape 65 prevents the plate separation. It is effective because it improves.

Fig. 6 is a flowchart showing a printing method of the screen printing machine of the present invention.

First, the adhesive tape 65 is affixed on the back surface of a workpiece | work, and it mounts on the table 70 (S11). Next, the surface is printed on the surface of the workpiece in S12. This printing is divided into a first print S13 and a second print S14.

Fig. 7 is a diagram showing the first printing.

The first skid 112 performs the first printing mainly for hole filling while moving in the direction of the arrow A. FIG. The first skid 112 performs a printing operation at a high pull pressure P1. In addition, the printing angle θ1 formed by the screen 90 and the first skid 112 is small. By increasing the phosphorus pressure P1 and / or by decreasing the printing angle θ1, the ink 84 can be easily filled in the through hole 61. In this case, no pattern is formed in the screen 90, and a pattern may be used.

Fig. 8 shows the second printing.

The second skid 113 moves in the direction of the arrow D, and the second printing is performed mainly for the purpose of thick application of the workpiece surface. The second skid 113 prints at a lower pull pressure P2 (P1> P2) than the first printing. The printing angle θ2 formed by the screen 90 and the second skid 113 is larger than the printing angle θ1 formed by the first skid 112 and the screen 90. The ink 84 can be thickly applied onto the work piece 50 by increasing the printing angle θ2 and / or by decreasing the phosphorus pressure P2.

Here, the feature is that the first printing is mainly used for hole filling, and the second printing is used for thick coating.

Moreover, the characteristic point is that a drying process is not provided between 1st printing and 2nd printing.

In this way, the first and second printings can be continuously performed in the moving path and the return path without providing a drying step, so that the back surface of the work piece 50 is kept flat by the adhesive tape 65 without being concave. Because there is. Even when the ink 84 is filled twice with respect to the through hole 61 while being wet, the workpiece 50 is not deformed at all, and the ink 84 is detoured into the back surface of the substrate of the through hole 61. Printing can be performed without work. When printing is continuously performed twice in the state as shown in Fig. 19, the drawback that the ink flows back into the back surface occurs, whereas in the present invention, the adhesive tape 65 is used to Since the entire back surface is flat and tightly covered, the ink 84 does not detour into the back surface.

6, the adhesive tape 65 is peeled from the workpiece in S15. And a workpiece | work is put into a drying chamber and dried in S16. In this case, the ink is made semi-dry or less dry. For example, the ink is dried to 50 to 70% of the solvent.

The reason why the drying is stopped in the semi-dry state is that if the solvent is dried until 100% of the solvent disappears, one side of the workpiece becomes wet once and is forcibly dried, causing warpage or distortion to the workpiece. Therefore, the drying is stopped in the semi-dry state so that warpage and distortion are not generated in the work piece 50. The semi-dry state means a dry state such that printing is not hindered at the time of backside printing described later. More specifically, the adhesive tape 65 may be adhered to the surface of the printed workpiece, and then the adhesive tape 65 may be dried so that the ink on the surface of the workpiece may not be peeled off by the adhesive tape 65. The degree of dryness is determined by the relative relationship with the adhesive force of the adhesive tape 65. When the adhesive force of the adhesive tape 65 is small, it may be wet even further, and when the adhesive force of the adhesive tape 65 is large, It is more preferable to dry further.

Returning to Fig. 6, the adhesive tape 65 is adhered to the surface of the work piece in S17 and placed on the table.

Next, the backside printing is performed in S18. It is preferable that this back printing also performs 1st printing and 2nd printing similarly to the surface printing of S12. However, in this backside printing, since the ink 84 is already filled in the through-hole 61 in surface printing, only one time of printing may be performed without performing 2 times of printing. Next, the adhesive tape 65 is peeled off in S21. At this time, as described above, the relationship between the adhesive force of the adhesive tape 65 and the semi-dry state of the ink should ensure that the ink is not peeled off by the adhesive tape 65. Finally, in S22, the workpiece 50 is placed in a drying chamber, and the front and back surfaces are dried to remove 100% of the solvent and completely dry.

Based on the flowchart of FIG. 6, drying is only semi-drying in S16 and complete drying in S22. Therefore, the number of drying is reduced from 4 times or 5 times to 1.5 times as compared with the related art. Thereby, the opportunity to generate the warpage and the distortion of the workpiece by drying are greatly reduced. In particular, when only one surface is printed, since only half drying is performed, the probability of warping on one side is reduced compared with the prior art.

According to the conventional printing method, since printing and drying are repeated, variations occur easily in the coating thickness of the ink. In contrast, in this embodiment, since the ink is only applied twice in a wet state and semi-dried or completely dried, variation in the coating thickness of the ink can be reduced.

The adhesive tape of this invention includes things other than the film 33 for a support base material. For example, the supporting base material may be cloth, paper, plastic, synthetic resin, or mesh.

Moreover, the thing other than the strip | belt-shaped thing which becomes roll shape is contained in the adhesive tape of this invention. For example, a plate- or patch-type adhesive seal, a pressure-sensitive adhesive plate, a pressure-sensitive adhesive plate, or a pressure-sensitive adhesive foil having the same shape and the same size as the work piece may be used.

The shape and the size may be different.

In addition, the adhesive tape of this invention may not coat | cover the workpiece | work whole surface, and may coat | cover only a part of workpiece | work. In addition, you may use it once and use it several times, without throwing it away.

Moreover, the adhesive tape of this invention may be a double-sided tape with an adhesive on both surfaces instead of just one side.

In addition, the adhesive may not exist in the whole surface of the film 33, and may exist only in one part. For example, the pressure-sensitive adhesive may be present only at the center portion of the film 33.

Moreover, an adhesive may be an intermittent type | mold, a stripe type, a check type, and a polka dot type.

<2nd embodiment>

9A and 9B show the relationship between the work piece 50 and the adhesive tape 65.

When the work 50 is carried in the direction of the arrow F, the adhesive tape 65 is also moved in the direction of the arrow F in synchronization with it. This movement is performed by the motor 36. As shown in Fig. 9B, when the printed workpiece 50 is taken out, the motor 36 is similarly operated to move the workpiece 50 in the direction of the arrow F. As shown in FIG.

In this way, the movement of the work piece 50 is performed by the movement of the adhesive tape 65. Moreover, positioning of the workpiece | work 50 is also performed by the movement stop of the adhesive tape 65. FIG. Conventionally, when the workpiece 50 is carried on the table 70, positioned, and taken out, an import mechanism, a positioning mechanism, and an export mechanism are required. However, according to this embodiment, it can be performed only by moving the adhesive tape 65. Therefore, the structure of the table 70 becomes considerably simple. In addition, when peeling the adhesive tape 65 from the workpiece | work 50, it is only necessary to wind up the winding roll 67, and the workpiece | work 50 is arrow-marked, peeling the adhesive tape 65 from the workpiece | work 50. Can be taken out in the direction F).

FIG. 10 shows a case where the adhesive tape 65 is peeled off from the work piece 50 in the direction opposite to the carrying out direction (arrow F) and 180 °.

Thus, when peeling the adhesive tape 65 from the workpiece | work 50, it is preferable to make peeling angle (theta) 3 more acute. This is because the peeling probability of the ink from the work piece 50 by the adhesive tape 65 can be made smaller as the acute angle is set.

Third Embodiment

FIG. 11 shows a case where the Teflon processed film 114 is disposed on the lower surface of the screen 90 as an anti-stick material.

Since the Teflon processed film 114 is Teflon processed, it is easy to peel from the adhesive tape 65. When the Teflon processed film 114 is adhered to the adhesive tape 65 by screen printing, the screen 90 and the Teflon processed film 114 are easily peeled off due to the presence of Teflon processing, and the work 50 and the adhesive tape are easily peeled off. 65 can maintain a planar state on the table. Although the Teflon processed film 114 may be arrange | positioned all around the screen 90, when the width W1 of the workpiece | work 50 and the width W2 of the adhesive tape 65 are the same, as shown in FIG. The Teflon processed film 114 may be arranged before and after the advancing direction of the adhesive tape 65.

FIG. 12 shows a case where the adhesive tape 65 is exposed to the table 70 by the same length L2 as the length L1 of the work piece 50.

In the case shown in Fig. 12, the consumption of the adhesive tape 65 can be reduced, and since the contact between the screen 90 and the adhesive tape 65 is completely eliminated, there is no need to arrange the Teflon processed film 114. .

As described above, according to the present invention, since the adhesive tape is disposed between the workpiece and the table, even if the thickness of the workpiece is thin, there is an effect that the workpiece can be fixed while keeping the workpiece flat on the table.

In addition, according to the present invention, even if the workpiece has a through hole, since the adhesive tape is adsorbed on the entire back surface of the work, ink can be filled in the through hole.

Moreover, according to this invention, since the uneven part is formed in the surface of an adhesive tape, the air of a through hole can be escaped and ink can be easily filled.

In addition, according to the present invention, since the pressure-sensitive adhesive of the adhesive tape is not dissolved in the solvent of the ink, the pressure-sensitive adhesive dissolved on the back surface of the work is not left as a contaminant.

In addition, according to the present invention, since the workpiece having the through hole is held by the adhesive tape, the ink can be continuously printed twice in a wet state.

In addition, according to the present invention, since two skids are used, printing can be performed on the same workpiece continuously in the moving path and the return path.

Claims (4)

In the screen device which loads a workpiece having a through hole on a table and performs screen printing by ink, A first skid for filling the through-hole of the workpiece with ink, And a second skid for applying ink to the surface of the workpiece. The screen of claim 1, wherein an angle formed by the first skid and the screen during screen printing of the first skid is smaller than an angle formed by the second skid and the screen during screen printing of the second skid. printer. The screen printing machine according to claim 1 or 2, wherein the pressure at the time of screen printing of the first skid is greater than the pressure at the time of screen printing of the second skid. The method according to claim 1, wherein the first skid and the second skid are attached to each other and are printed by the first skid in the moving path with respect to the same surface of one piece of work, and by the second skid in the return road. Screen printing machine characterized in that for performing.