Printing device, circuit board printing method and screen

Abstract

The present invention discloses a printing device, a printing method for a circuit board, and a screen. The printing device includes a printing machine and a screen, the printing machine includes a workbench, a screen clamping mechanism, a printing unit, and a boss fixed on the workbench; the screen includes a first screen frame, a second screen frame, and a mesh piece, the first and second screen frames are stacked and detachably connected, and the mesh piece is arranged between the first and second screen frames; the first and second screen frames are both detachably fixed on the screen clamping mechanism, a first distance is provided between the side of the first screen frame away from the mesh piece and the side corresponding to the mesh piece, a second distance is provided between the side of the second screen frame away from the mesh piece and the side corresponding to the mesh piece, a third distance is provided between the upper end face of the boss and the upper surface of the workbench, the third distance is greater than or equal to the first distance, and the third distance is greater than or equal to the second distance; the length of the upper end face of the boss along any direction is less than the length of the mesh piece along the corresponding direction. This solution can save the cost of screen consumables.

Description

Technical Field

[0001] The invention relates to the technical field of circuit board printing, and in particular to a printing device, a circuit board printing method and a screen. Background Art

[0002] When printing solder mask on a circuit board, a printer and a stencil are generally needed to assist the operation. The usual practice is to fix the circuit board on the workbench of the printer, clamp the stencil on the printer, and the printer drives the stencil to move downward to contact the circuit board. Then the printing unit of the printer prints ink on the stencil, and the ink is printed on the circuit board through the stencil.

[0003] like Figures 1 to 3 As shown, most existing screens include a square screen frame 11 and a grid member 12 fixed on the screen frame 11. One end of the screen frame 11 along the thickness direction is connected to the screen clamping mechanism of the printer, and the grid member 12 is fixed to the other end of the screen frame 11 along the thickness direction to contact the circuit board. Therefore, the grid member 12 also has a relative A surface (when the screen is clamped on the printer, the A surface is close to the screen clamping mechanism) and a B surface (when the screen is clamped on the printer, the B surface is away from the screen clamping mechanism).

[0004] For double-sided printed circuit boards, usually, the graphics on the front and back sides of the circuit board are mirror images. When printing, you can first print on the front side of the circuit board, then bake it, and after the ink on the front side of the circuit board is dried, set the circuit board in reverse so that the printer can print on the back side of the circuit board.

[0005] Limited by the structure of the existing stencil, the mesh member 12 of the stencil can only be used on one side, that is, only the B side can be used, and the A side cannot be used. This is because, when the stencil is turned over for use, there is no part on the B side of the mesh member 12 that can be clamped by the stencil clamping mechanism, or in other words, the B side is difficult to fix on the printing press. In addition, the existence of the screen frame 11 also makes it impossible for the A side of the mesh member 12 to contact the circuit board when the stencil is turned over for use, and thus printing cannot be performed. Therefore, at present, a circuit board needs to use a positive stencil (such as Figure 2 as shown) and reverse stencil (as Figure 3 The two stencils are used for printing, and the graphics on the positive stencil and the reverse stencil are mirrored. For production lines with large production volumes, sufficient stencils need to be prepared to meet production needs.

[0006] In summary, how to reduce the amount of stencils used in the printing process to reduce the consumable material cost and material storage space of the stencils is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0007] In order to overcome the defects in the prior art, the embodiments of the present invention provide a printing device, a printing method for a circuit board and a screen, which are used to solve at least one of the above problems.

[0008] The embodiment of the present application discloses: a printing device, comprising a printing machine and a screen, the printing machine comprising a workbench, a screen clamping mechanism arranged above the workbench, a printing unit arranged above the workbench, and a boss fixed on the workbench; the screen comprises a first screen frame, a second screen frame and a grid member, the first screen frame and the second screen frame are stacked and detachably connected, and the grid member is arranged between the first screen frame and the second screen frame; the first screen frame and the second screen frame are both detachably fixed to the screen clamping mechanism, a first distance is provided between a side of the first screen frame away from the grid member and a side corresponding to the grid member, a second distance is provided between a side of the second screen frame away from the grid member and a side corresponding to the grid member, a third distance is provided between an upper end surface of the boss and an upper surface of the workbench, the third distance is greater than or equal to the first distance, and the third distance is greater than or equal to the second distance; the length of the upper end surface of the boss along any direction is less than the length of the grid member along the corresponding direction.

[0009] Specifically, when the first mesh frame is located above the second mesh frame, the mesh member is used to process the first end surface of the product; when the first mesh frame is located below the second mesh frame, the mesh member is used to process the second end surface of the product; the first end surface and the second end surface of the product are arranged opposite to each other.

[0010] Specifically, the boss is connected to the workbench by a pin, and the upper end surface of the pin is not higher than the upper end surface of the boss.

[0011] Specifically, a plurality of air holes are provided on the boss.

[0012] Specifically, the boss is provided with a plurality of positioning holes for positioning the circuit board.

[0013] The embodiment of the present application also discloses: a method for printing a circuit board, which uses the printing device as described in the embodiment of the present application to print the circuit board, defines the side of the grid member facing away from the first mesh frame as the first side, and defines the side of the grid member facing away from the second mesh frame as the second side, the circuit board has a front side and a back side arranged opposite to each other, the first side of the grid member is used to form a pattern on the front side of the circuit board, and the second side of the grid member is used to form a pattern on the back side of the circuit board; the method comprises the following steps:

[0014] Placing the circuit board on the boss, with the back side of the circuit board abutting against the boss, so that the front side of the circuit board faces the printing unit;

[0015] Fixing the first mesh frame of the mesh plate on the mesh plate clamping mechanism so that the first surface of the mesh member can abut against the front surface of the circuit board;

[0016] Using the printing unit to print on the front side of the circuit board;

[0017] Drying the front side of the circuit board;

[0018] The circuit board after front side drying is placed on the boss, with the front side of the circuit board against the boss,

[0019] so that the reverse side of the circuit board faces the printing unit;

[0020] The mesh plate is removed from the mesh plate clamping mechanism and cleaned, and the second mesh frame of the cleaned mesh plate is fixed to the mesh plate clamping mechanism so that the second surface of the mesh member can abut against the reverse surface of the circuit board;

[0021] Printing the reverse side of the circuit board using the printing unit;

[0022] The reverse side of the circuit board is dried.

[0023] The embodiment of the present application also discloses: a mesh plate, comprising a first mesh frame, a second mesh frame and a mesh piece, wherein the first mesh frame and the second mesh frame are stacked and detachably connected, and the mesh piece is arranged between the first mesh frame and the second mesh frame.

[0024] Specifically, the grid member is bonded to a side of the first grid frame facing the second grid frame, and / or the grid member is bonded to a side of the second grid frame facing the first grid frame.

[0025] Specifically, the first mesh frame and the second mesh frame are connected by screws.

[0026] Specifically, the first mesh frame or the second mesh frame is provided with a countersunk hole for completely accommodating the head of the screw.

[0027] The present invention has at least the following beneficial effects:

[0028] The printing device of this embodiment can print on both sides of a circuit board with the cooperation of the boss and the screen with a unique structure. Compared with the prior art, the structure of the grid pieces on the screen of this embodiment and the graphic processing method remain unchanged, and the above scheme can be realized by only changing the structure of the screen frame. Therefore, this method of combining the original forward screen and the reverse screen into one screen through optimization can greatly reduce the amount of grid pieces and screen frames, reduce the cost of consumables, and at the same time, there is no need to set up too much space for holding screens on the production line, saving the floor space of the production line.

[0029] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 It is a bottom view of the prior art showing a positive screen installed on a printing press;

[0032] Figure 2 It is a bottom view of the reverse screen installed on the printing press in the prior art;

[0033] Figure 3 It is a cross-sectional view of a mesh plate in the prior art;

[0034] Figure 4 is a schematic diagram of the structure of the screen board in an embodiment of the present invention;

[0035] Figure 5 yes Figure 4 Sectional view at AA in the middle;

[0036] Figure 6 yes Figure 5 A partial enlarged view of point B in the middle;

[0037] Figure 7 is a schematic diagram of the operation of the printing device in an embodiment of the present invention;

[0038] Figure 8 yes Figure 7 A partial enlarged view of point C in the middle.

[0039] The figure markings of the above drawings are: 11, screen frame; 111, first screen frame; 112, second screen frame; 1110, countersunk hole; 12, mesh member; 121, first surface; 122, second surface; 13, screw; 21, workbench; 22, boss; 3, printing unit; 4, circuit board. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Combination Figures 4 to 8 As shown, the printing device of this embodiment can be used to print a circuit board 4, and the printing device specifically includes a printing machine and a screen. The printing machine includes a workbench 21, a screen clamping mechanism (not shown) arranged above the workbench 21, a printing unit 3 arranged above the workbench 21, and a boss 22 fixed on the workbench 21.

[0042] Key References Figures 4 to 6 As shown, the mesh plate may include a first mesh frame 111, a second mesh frame 112 and a mesh member 12. The first mesh frame 111 and the second mesh frame 112 are stacked and detachably connected, and the mesh member 12 is arranged between the first mesh frame 111 and the second mesh frame 112. The mesh member 12 is stretched tight on the first mesh frame 111 or the second mesh frame 112 and has a certain tension. The mesh plate clamping mechanism is used to install the mesh plate, and the first mesh frame 111 and the second mesh frame 112 of the mesh plate can be fixedly connected to the mesh plate clamping mechanism in turn, so the first mesh frame 111 and the second mesh frame 112 are detachably connected to the mesh plate clamping mechanism.

[0043] Key References Figure 8As shown, a first distance L1 is provided between a side of the first mesh frame 111 facing away from the mesh element 12 and a side corresponding to the mesh element 12, and a second distance L2 is provided between a side of the second mesh frame 112 facing away from the mesh element 12 and a side corresponding to the mesh element 12. In other words, one side of the mesh element 12 faces the first mesh frame 111, and the first distance L1 is provided between the side facing away from the mesh element 12 of the first mesh frame 111, and the other side of the mesh element 12 faces the second mesh frame 112, and the second distance L2 is provided between the side facing away from the mesh element 12 of the second mesh frame 112. There is a third distance L3 between the upper end surface of the boss 22 and the upper surface of the workbench 21, and the third distance L3 is greater than or equal to the first distance L1, and the third distance L3 is greater than or equal to the second distance L2, so as to ensure that when the first screen frame 111 is connected to the screen clamping mechanism, the second screen frame 112 does not contact with the workbench 21 of the printing press, thereby causing mechanical interference. Similarly, when the second screen frame 112 is connected to the screen clamping mechanism, the first screen frame 111 may not contact with the workbench 21, so as to avoid causing mechanical interference.

[0044] The length of the upper end surface of the boss 22 in any direction is smaller than the length of the mesh member 12 in the corresponding direction, so as to ensure that the first mesh frame 111 or the second mesh frame 112 can avoid the circuit board 4, and further ensure that the two sides of the mesh member 12 can be in full contact with the circuit board 4 on the boss 22, so as to achieve printing operation. Preferably, the upper end surface of the boss 22 extends in the horizontal direction, and is generally square, and the first mesh frame 111 and the second mesh frame 112 can also be generally square, then, the inner length of the first mesh frame 111 and the second mesh frame 112 is greater than or equal to the length of the boss 22, and the inner width of the first mesh frame 111 and the second mesh frame 112 is greater than or equal to the width of the boss 22.

[0045] The following key references Figure 7 and Figure 8 To illustrate the working principle of the printing device of this embodiment. For the sake of convenience, the side of the grid member 12 facing away from the first mesh frame 111 can be defined as the first surface 121, and the side of the grid member 12 facing away from the second mesh frame 112 can be defined as the second surface 122. The circuit board 4 has a front side (that is, the first end face of the product) and a back side (that is, the second end face of the product) that are arranged opposite to each other. The first surface 121 of the grid member 12 is used to form the graphics on the front side of the circuit board 4, and the second surface 122 of the grid member 12 is used to form the graphics on the back side of the circuit board 4. It should be noted that the graphics in the accompanying drawings are only an example. The grid member 12 of this embodiment can perform corresponding graphics processing according to any graphics required on the circuit board 4. The specific working principle of the printing device is as follows:

[0046] Place the circuit board 4 on the boss 22 so that the back side of the circuit board 4 abuts against the boss 22 and the front side of the circuit board 4 faces the printing unit 3;

[0047] Fix the first mesh frame 111 of the mesh plate on the mesh plate clamping mechanism so that the first surface 121 of the mesh member 12 can abut against the front surface of the circuit board 4, thereby processing the front surface of the circuit board 4;

[0048] The printing unit 3 is used to print the front side of the circuit board 4;

[0049] Drying the front side of the circuit board 4 to dry the ink;

[0050] Place the circuit board 4 after drying on the front side on the boss 22, so that the front side of the circuit board 4 faces downward and abuts against the boss 22.

[0051] so that the reverse side of the circuit board 4 faces upward toward the printing unit 3;

[0052] The stencil is removed from the stencil clamping mechanism and the ink on the mesh member 12 is cleaned, and the second mesh frame 112 of the cleaned stencil is fixed to the stencil clamping mechanism so that the second surface 122 of the mesh member 12 can abut against the back surface of the circuit board 4, thereby processing the back surface of the circuit board 4;

[0053] The printing unit 3 is used to print the reverse side of the circuit board 4;

[0054] The reverse side of the circuit board 4 is dried.

[0055] By means of the above scheme, the printing device of this embodiment can print on both sides of a circuit board 4 with the cooperation of the boss 22 and the screen with a unique structure. Compared with the prior art, the structure and graphic processing method of the grid member 12 on the screen of this embodiment remain unchanged, and the above scheme can be realized by only changing the structure of the screen frame. Therefore, this method of combining the original forward screen and the reverse screen into one screen through optimization can greatly reduce the amount of grid members 12 and screen frames, reduce the cost of consumables, and at the same time, there is no need to set up too much space for holding screens on the production line, saving the floor space of the production line.

[0056] Specifically, the boss 22 and the workbench 21 of this embodiment can be processed in an integral molding manner, or can be connected by a pin (not shown). When the boss 22 and the workbench 21 are connected by a pin, the upper end surface of the pin is not higher than the upper end surface of the boss 22, that is, the pin is sunken into the boss 22 to avoid affecting the circuit board 4 placed on the boss 22.

[0057] Preferably, the boss 22 can be made of epoxy resin. The boss 22 can be provided with a plurality of air holes (not shown) that penetrate the boss 22 in the thickness direction, and the air holes can generally correspond to the holes on the circuit board 4 so that the gas in the ink can be discharged during printing. The boss 22 can also be provided with a plurality of positioning holes (not shown) for positioning the circuit board 4.

[0058] Specifically, the mesh member 12 may be bonded to the side of the first mesh frame 111 facing the second mesh frame 112 by gluing, and / or the mesh member 12 may be bonded to the side of the second mesh frame 112 facing the first mesh frame 111. The gluing method may improve the connection strength between the mesh member 12 and the first mesh frame 111 and / or the second mesh frame 112, and ensure that the mesh member 12 has sufficient tension.

[0059] Specifically, Figure 6 As shown, the first mesh frame 111 and the second mesh frame 112 can be connected by screws 13. The first mesh frame 111 or the second mesh frame 112 can be provided with a countersunk hole 1110 for completely accommodating the head of the screw 13. When the screw 13 connects the first mesh frame 111 and the second mesh frame 112, both ends of the screw 13 do not protrude from the first mesh frame 111 and the second mesh frame 112. In other words, the screw 13 is completely buried in the first mesh frame 111 and the second mesh frame 112 to avoid mechanical interference with the workbench 21.

[0060] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A printing device, characterized in that: The invention comprises a printing machine and a screen, wherein the printing machine comprises a workbench, a screen clamping mechanism arranged above the workbench, a printing unit arranged above the workbench, and a boss fixed on the workbench; the screen comprises a first screen frame, a second screen frame and a grid member, wherein the first screen frame and the second screen frame are stacked and detachably connected, and the grid member is arranged between the first screen frame and the second screen frame; The first mesh frame and the second mesh frame are both detachably fixed to the mesh plate clamping mechanism, a first distance is defined between a side of the first mesh frame facing away from the mesh member and a side corresponding to the mesh member, a second distance is defined between a side of the second mesh frame facing away from the mesh member and a side corresponding to the mesh member, a third distance is defined between an upper end surface of the boss and an upper surface of the workbench, the third distance is greater than or equal to the first distance, and the third distance is greater than or equal to the second distance; a length of an upper end surface of the boss in any direction is less than a length of the mesh member in a corresponding direction; When the first mesh frame is located above the second mesh frame, the mesh member is used to process the first end surface of the product; when the first mesh frame is located below the second mesh frame, the mesh member is used to process the second end surface of the product; the first end surface and the second end surface of the product are arranged opposite to each other; The boss and the workbench are connected by a pin, and the upper end surface of the pin is not higher than the upper end surface of the boss; The boss is provided with a plurality of air holes; The boss is provided with a plurality of positioning holes for positioning the circuit board; The following method is used to print the circuit board, the side of the grid member facing away from the first mesh frame is defined as the first side, the side of the grid member facing away from the second mesh frame is defined as the second side, the circuit board has a front side and a back side arranged opposite to each other, the first side of the grid member is used to form a pattern on the front side of the circuit board, and the second side of the grid member is used to form a pattern on the back side of the circuit board; the method comprises the following steps: Placing the circuit board on the boss, with the back side of the circuit board abutting against the boss, so that the front side of the circuit board faces the printing unit; Fixing the first mesh frame of the mesh plate on the mesh plate clamping mechanism so that the first surface of the mesh member can abut against the front surface of the circuit board; Using the printing unit to print on the front side of the circuit board; Drying the front side of the circuit board; Placing the circuit board after drying on the front side on the boss, with the front side of the circuit board abutting against the boss, so that the back side of the circuit board faces the printing unit; The mesh plate is removed from the mesh plate clamping mechanism and cleaned, and the second mesh frame of the cleaned mesh plate is fixed to the mesh plate clamping mechanism so that the second surface of the mesh member can abut against the reverse surface of the circuit board; Printing the reverse side of the circuit board using the printing unit; The reverse side of the circuit board is dried.

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