JP4681335B2 - Screen printing machine - Google Patents

Description

  The present invention relates to a clean printing machine that moves a squeegee relative to a screen in parallel to print a fluid on the screen onto a substrate.

  This type of clean printing machine is disclosed in, for example, Patent Document 1 and the like. In particular, as shown in FIG. 7, the squeegee head 50 includes a squeegee support member 21 that is supported by being inclined at a predetermined angle. A holding plate 23 whose upper portion is fixed to one surface (lower surface) of the squeegee supporting member with a screw (not shown), and a rubber squeegee having an upper portion sandwiched between the squeegee supporting member 21 and the holding plate 23 and having elasticity. 22.

  A portion below the substantially middle position in the vertical dimension of the squeegee 22 extends downward from the lower ends of the squeegee support member 21 and the pressing plate 23.

  FIG. 9 is a side sectional view of a conventional squeegee head 51 using a thin metal plate for the squeegee. The squeegee head 51 in FIG. A plate-shaped squeegee support member 27 inclined at a predetermined angle with respect to the squeegee support member 27, the presser plate 30 fixed to one surface of the squeegee support member 27, and the squeegee support member 27 and the presser plate 30. 27 includes a plate-like squeegee 28 and a thin plate-like squeegee 29 that extend in parallel with the plate 27.

The portion below the squeegee 29 from the substantially middle position in the vertical direction extends downward from the lower end of the pressing plate 30 and is not exposed and pressed.
JP 2001-287337 A

  Therefore, in such a conventional screen printing machine, as described above, the upper portion of the squeegee 22 shown in FIG. 7 is only sandwiched between the squeegee support member 21 and the pressing plate 23. As described above, when the squeegee 22 comes into contact with the screen plate 7 and is further pressed downward, the entire lower portion of the squeegee 22 that is not pressed by the pressing plate 23 is greatly deformed, that is, the lower portion is bent. Since the pressure on the printing material decreases, it is necessary to further apply a pressing force, that is, a printing pressure, applied to the squeegee 22 in order to print a solder paste that is a fluid, for example. As described above, when the printing pressure is excessively applied, there arises a problem that the durability of the squeegee 22 is lowered, and the maintenance interval such as replacement is shortened.

  Also in the squeegee 29 shown in FIG. 9, when the squeegee 29 is pressed downward, the entire lower part of the squeegee 29 that is not pressed is deformed as shown in FIG. Since the pressure on the printing material decreases, it is necessary to further apply a pressing force applied to the squeegee 29, that is, a printing pressure, in order to surely perform printing. The maintenance interval was also shortened.

  Therefore, an object of the present invention is to avoid a large deformation of the squeegee as much as possible, to reliably print the fluid on the printing material, and to improve the durability of the squeegee.

For this reason, according to the first aspect of the present invention, the screen is arranged so as to face the substrate, the substrate is opposed to the substrate with the screen being sandwiched, and the flow on the screen is moved relatively parallel to the screen. In a screen printing machine comprising a squeegee for printing an animal on the substrate, an elastic squeegee that is supported at an angle and has a rectangular cross section, and an upper end of the squeegee that is provided at the upper surface of the squeegee. A squeegee support member that supports the squeegee, and a squeegee presser plate that is provided under the squeegee and sandwiches the squeegee between the squeegee support member, the lower end of the squeegee presser plate being slightly above the lower end of the squeegee together is positioned, said to form a step in the lower portion of the squeegee holding plate, below this level difference is supporting thinner cross section than the upper linear And said that the content was.

According to a second aspect of the present invention, there is provided a screen disposed so as to face the printing material, and opposed to the printing material with the screen sandwiched therebetween, and the fluid on the screen is moved in parallel relative to the screen. In a screen printing machine provided with a squeegee that prints on the substrate, a squeegee made of a metal plate that is supported at an angle and has elasticity, and a squeegee support that is provided on the upper surface of the squeegee and supports the bottom of the squeegee. And a squeegee presser plate provided between the member and the squeegee support member and sandwiching the squeegee between the lower end of the squeegee presser plate and a lower end of the squeegee. step to form the bottom of the holding plate, that below this level difference which is thinner section than the top with that it has a linear support pieces And butterflies.

According to the present invention, the range of deformation of the squeegee can be kept narrow by sandwiching the squeegee between the squeegee support member and the support piece formed thinly below the level difference between the squeegee holding plate and the straight section . Durability can be improved, and rolling of fluid in the space formed between the lower part of the squeegee presser plate and the screen, and the support piece and the screen having a thin and straight section below the step The viscosity of the fluid can be further reduced by both the rolling of the fluid in the space formed between the two, and the substrate can be reliably printed.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  Reference numeral 1 in FIG. 1 denotes a screen printing machine. A solder paste W (not shown) as a coating agent is applied in a desired pattern so that chip-shaped electronic components are mounted on the upper surface of a printed board 2 conveyed from an upstream device (not shown). Applied.

  Reference numeral 3 denotes a mounting table on which the substrate 2 is mounted, and is mounted in a state where the substrate 2 is positioned by a positioning mechanism (not shown). Reference numeral 4 denotes a moving table provided below the mounting table 3, and the mounting table 3 is moved by the movement of the moving table 4. That is, the mounting table 3 is moved up and down by the vertical movement of the cylinder 5 that moves the moving table 4 up and down. Further, the moving table 4 can be moved horizontally by a moving mechanism (not shown), and is moved from a positioning station (not shown) for receiving the substrate 2 on the mounting table 3 from the upstream apparatus to a printing station shown in FIG.

  Reference numeral 6 denotes a screen, which is composed of a screen plate 7 provided with an opening (not shown) as a printed pattern hole formed corresponding to a desired circuit pattern of the substrate 2, and a screen frame 8 surrounding the plate 7. The Reference numeral 10 shown in FIG. 2 denotes a squeegee base attached to a base (not shown). Then, the rotation of a printing motor (not shown) is transmitted to the drive pulley 12 and is rotated, and the squeegee belt 14 stretched between the drive pulley 12 and the driven pulley 13 is moved to attach to the belt 14. The squeegee table 10 is moved. A pulse motor is used as a printing motor. A servo motor may be used.

  Two squeegee heads 15 facing each other are mounted on the squeegee base 10 so as to be vertically movable by operation of a squeegee up / down cylinder 17 guided by two squeegee up / down guides 16. The squeegee head 15 descends and moves while pressing the screen plate 7 of the screen 6 against the substrate 2, and solder paste W supplied on the screen plate 7 is provided corresponding to the pattern of the substrate 2. Printing is performed on the substrate 2 through an opening (not shown).

  FIG. 3 is a side sectional view of the squeegee head 15 provided with the squeegee according to the present invention. The squeegee head 15 is composed of a squeegee support member 24, an elastic rubber squeegee 25, and a squeegee support member. 24 is provided with a squeegee pressing plate 26 fixed through screws (not shown). Then, the squeegee support member 24 is extended to substantially the same position as the lower end of the squeegee 25 with respect to the conventional squeegee head, and the squeegee support member 24 faces the upper surface of the squeegee 25 (the surface facing the moving direction side when printing with the squeegee). ) Is supported to its lower end.

  In addition, the presser plate 26 is lower than the conventional press plate 26, that is, the lower surface, that is, the surface opposite to the upper surface of the squeegee 25, that is, the lower surface (surface on the screen side). The surface 26) extends downward, that is, to the screen side, and a step 26A is formed in the lower portion, and a support piece 26a thinner than the upper and middle portions is formed.

  For this reason, the squeegee head 15 is different from the conventional squeegee shown in FIG. 7 in that when the squeegee head 15 is lowered and hits the screen plate 7 as shown in FIG. Only a part of the side is elastically deformed.

  As described above, the pressing plate 26 is positioned slightly above the lower end of the squeegee 25 so that the lower end of the pressing plate 26 does not contact the screen plate 7 and the solder paste W is not pushed out of the printing range. A step 26A and a thin support piece 26a are formed, and are formed into a relief shape step by step.

  For example, as shown in FIG. 4, the lower end of the pressing plate 26 has a lower limit at the lower limit so that the distance between the lower end of the pressing plate 26 and the screen 7 is low so that the solder paste rolling is optimized when the squeegee 25 moves during printing. It is set to be about 4 to 5 mm.

  Further, the plate-like squeegee 25 can be variously selected according to need to be subjected to surface treatment in order to prevent chemical changes such as corrosion or to adjust the strength.

  The operation of the screen printing machine configured as described above will be described below.

  When the printing operation is started, the mounting table 3 positioned on the positioning station side is first below the transfer level of the supply conveyor, and the substrate 2 transferred from the upstream device by the conveyor is positioned above the mounting table 3. When done, the conveyor is stopped.

  Next, the mounting table 3 is raised from the transport level by the cylinder 5, and the substrate 2 is mounted on the table 3. The mounting table 3 on which the substrate 2 is mounted is moved to the printing station by the moving mechanism. Then, for example, the squeegee upper / lower cylinder 17 is driven and lowered onto the screen plate 7 in a state where the left squeegee head 15 shown in FIG. 1 is adjusted to a desired squeegee angle by the angle adjusting mechanism. Then, the squeegee 25 is pressed against the screen plate 7 and moved to the right in FIG. 1 based on a desired squeegee speed by driving the printing motor, so that the solder paste W supplied onto the screen plate 7 is transferred to the screen plate 7. Printing is performed on the substrate 2 through the drilled opening.

  Thus, when printing is performed, as shown in FIG. 4, the portion of the squeegee 25 below the lower end of the pressing plate 26 is deformed, while the other portions are supported by the squeegee support member 24, Since the range and amount of deformation of the squeegee 25 are suppressed when the surface in the moving direction is pressed by the pressing plate 26, it is not necessary to apply extra printing pressure, and the durability of the squeegee 25 can be improved, such as replacement. The maintenance interval can be extended.

  In addition, the movement of the squeegee 25 in the space 40 formed between the surface of the squeegee 25 in the moving direction and the screen plate 7 due to the deformation of the portion of the squeegee 25 below the lower end of the presser plate 26 shown in FIG. As a result, rolling occurs in the solder paste, and the solder paste also forms in the space 41 on the moving direction side of the squeegee 25 with respect to the thin support piece 26a of the pressing plate 26 and in the space 41 formed between the screen plate 7 and the solder paste. Rolling occurs, and rolling of these solder pastes can further reduce the viscosity of the solder paste, and as a result, printing can be performed reliably. Further, even when the amount of solder paste decreases, the solder paste rolling continues in the space 41, so that printing can be continued.

  Further, at the lower end portion of the squeegee 25 slightly above the lower end of the squeegee 25, for example, in the range of 2 mm, the angle formed between the surface on the moving method side of the squeegee 25 and the screen plate 7 by deformation is more than the above range. The acute angle is even smaller than the upper part. As a result, printing of the solder paste at the lower part of the squeegee 25, that is, filling of the substrate to be printed can be more reliably performed together with the rolling action of the solder paste.

  When printing in the forward direction is completed, the left squeegee 25 is lowered by driving the cylinder 17 and the right squeegee 25 is lowered similarly by driving the cylinder 17 to perform printing in the backward direction. The squeegee 15 is raised. If only one-direction printing is required, two substrates 2 can be printed by the forward-direction printing and the backward-direction printing.

  After the printing is completed, the positioning of the mounting table 3 is released, the table 3 is lowered below the transport level by the cylinder 5, and the substrate 2 is discharged by a discharge conveyor (not shown). After the substrate 2 is discharged, the mounting table 3 is returned from the printing station to the positioning station by the moving mechanism to prepare for the next substrate 2 supply. Thereafter, the printing operation is continued in the same manner.

  In this way, the printing operation of the substrate 2 is repeated, and the printing operation is performed based on, for example, the number-of-prints data stored in a storage device (not shown).

  Hereinafter, other embodiments of the present invention will be described.

  FIG. 5 is a side sectional view of the squeegee head of the present invention. The squeegee head is supported by a plate-like squeegee support member 31 that is inclined at a predetermined angle with respect to a horizontal plane, and screws (not shown) on the squeegee support member 31. And a squeegee that is sandwiched between the squeegee support member 31 and the squeegee plate 34 and supports the squeegee together with the squeegee support member 31 and is made of metal and has a thin plate-like elasticity. 33.

  In the squeegee head, compared to the conventional squeegee head shown in FIG. 9, the squeegee support member 31 has substantially the same shape as the squeegee support member 27, and the support plate 32 is slightly cut away and shortened. Furthermore, the lower part of the presser plate 34 is extended to the screen side so as to have substantially the same shape as the presser plate 26. At the lower part of the presser plate 34, a step 34A and a support piece 34a whose thickness is thinner than the upper part are formed. It is formed into a relief shape step by step. For this reason, the squeegee 33 is sandwiched between the support plate 32 and the pressing plate 34 except for its lower part.

  As described above, the squeegee 33 is lower than the conventional squeegee shown in FIG. 9, and the squeegee head is lowered and the printing pressure is applied to the squeegee 33 as shown in FIG. Sometimes only the lower part of the squeegee 33 bends. Further, the lower end of the pressing plate 34 is set in advance so that there is an interval of about 10 mm between the lower end of the pressing plate 34 and the screen plate 7 so as not to contact the screen plate 7.

  At the time of printing, the squeegee 33 is deformed as shown in FIG. 6 and the portion of the squeegee 33 below the lower end of the pressing plate 34 is deformed, while the other portions are supported by the squeegee support member 31. Since the range and the amount of deformation of the squeegee 33 are suppressed when the surface in the moving direction is pressed by the pressing plate 34, it is not necessary to apply extra printing pressure, and the durability of the squeegee 33 can be improved. The maintenance interval can be extended.

  In addition, the squeegee 25 moves in the space 40 formed between the surface of the squeegee 33 on the moving direction side and the screen plate 7 due to the deformation of the portion of the squeegee 33 below the lower end of the presser plate 34 shown in FIG. As a result, rolling occurs in the solder paste, and the solder paste also forms in the space 41 on the moving direction side of the squeegee 33 from the thin support piece 34a of the pressing plate 34 and in the space 41 formed between the screen plate 7 and the solder paste. Rolling occurs, and rolling of both solder pastes can further reduce the viscosity of the solder paste, and as a result, printing can be performed reliably. Further, even when the amount of solder paste decreases, the solder paste rolling continues in the space 41, so that printing can be continued.

  Further, at the lower end of the squeegee 25 in a slight range upward from the lower end of the squeegee 33, the angle formed between the surface on the moving method side of the squeegee 33 and the screen plate 7 due to the deformation is higher than the above range. The acute angle is smaller than that of the portion. As a result, the printing pressure can be maintained and the solder paste can be printed at the lower portion of the squeegee 33, that is, the printed material can be filled together with the rolling action of the solder paste.

  In addition, the thin plate-like squeegee 33 can be configured by stacking a plurality of thin plates in order to easily adjust the bending rate and the bending amount.

  The angle of the squeegee can be variously changed according to the viscosity of the solder paste W, the print pattern hole diameter, the hole pitch, and the like by an angle adjusting mechanism (not shown).

  Further, the support plate 32 and the thin plate-like squeegee 33 can be variously changed in thickness, material, strength, deflection rate, and the like according to the viscosity of the solder paste W, the print pattern hole diameter, the hole pitch, and the like.

  In addition, the support plate 32 and the thin plate-like squeegee 33 can be variously selected as needed to perform surface treatment in order to prevent chemical changes such as corrosion or to adjust the strength.

  Further, the shape of the relief plate 34 on the screen side can be variously changed according to the viscosity of the solder paste W, the diameter of the printed pattern, the hole pitch, and the like.

  Furthermore, although the case where this invention was applied to the screen printer which prints cream solder was demonstrated in embodiment mentioned above, this invention can also be applied to the screen printer which prints fluids other than cream solder. Further, the substrate to be printed is not limited to the circuit board.

  In the above-described embodiment, the case where the present invention is applied to the screen printing machine that performs printing by moving the screen and the printed material stationary and moving the squeegee is described, but the screen and the printed material are moved stationary. The present invention can also be applied to a screen printing machine.

  Although the embodiments of the present invention have been described above, various alternatives, modifications, and variations can be made by those skilled in the art based on the above description, and the present invention is not limited to the various alternatives described above without departing from the spirit of the present invention. It includes modifications or variations.

It is a figure which shows the screen printing machine which can apply this invention. It is a figure which shows a printing station. It is a sectional side view of a squeegee head. It is a sectional side view at the time of squeegee head lowering. It is a sectional side view of the squeegee head of other embodiment. It is a sectional side view at the time of squeegee head lowering of other embodiments. It is a sectional side view of the conventional squeegee head. It is a sectional side view of the conventional squeegee head. It is a sectional side view at the time of the conventional squeegee head lowering. It is a sectional side view at the time of the conventional squeegee head lowering.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Screen printer 2 Printed circuit board 3 Mounting stand 6 Screen 7 Screen board 15 Squeegee head 24 Squeegee support member 25 Squeegee 26 Holding board 31 Squeegee support member 32 Squeegee 33 Thin plate-like squeegee

Claims (2)

A screen arranged so as to face the printing material, and the printing material facing the printing material across the screen, and the fluid on the screen is printed on the printing material by moving in parallel relative to the screen. In a screen printing machine having a squeegee to perform, an elastic squeegee that is inclined and supported and has a rectangular cross section, and a squeegee support member that is provided on the upper surface of the squeegee and supports from the upper part to the substantially lower end of the squeegee, A squeegee presser plate provided under the squeegee and sandwiching the squeegee between the squeegee support member, the lower end of the squeegee presser plate being positioned slightly above the lower end of the squeegee, and the squeegee presser a step is formed in the lower portion of the plate, below this level difference to characterized in that the thinner cross section than the upper portion and the linear support pieces Screen printing machine. A screen arranged so as to face the printing material, and the printing material facing the printing material across the screen, and the fluid on the screen is printed on the printing material by moving in parallel relative to the screen. A squeegee comprising an elastically supported metal plate, a squeegee support member provided on an upper surface of the squeegee for supporting the squeegee except for a lower portion of the squeegee, A squeegee presser plate provided between the squeegee support member and the squeegee support member, wherein a lower end of the squeegee presser plate is positioned above the lower end of the squeegee and a step is formed below the squeegee presser plate. is formed and is lower than the step, characterized in that the thinner cross section than the top with that it has a linear support pieces disk Over screen printing machine.

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