JP2010225665A - Paint coating system, paint coating apparatus, and printed wiring board manufacturing method - Google Patents

Abstract

A paint coating system, a paint coating device, and a method for manufacturing a printed wiring board are provided to improve the reliability of a printed wiring board to be manufactured.
A first mesh sheet 122a covering one surface of a printed wiring board 9 is disposed opposite to the first mesh sheet 122a and opposite to one surface of the printed wiring board 9. A second mesh sheet 122b that covers the surface on the side, a first application roll 12a that is movably provided on the first mesh sheet 122a and that applies a paint to one surface of the printed wiring board 9, The printed wiring board 9 is provided so as to follow the first coating roll 12a and to be movable on the second mesh sheet 122b, and is opposite to the surface coated with the paint by the first coating roll 12a. And a second application roll 12b for applying a paint to the surface.
[Selection] Figure 1

Description

  The present invention relates to a paint coating system, a paint coating apparatus, and a method for manufacturing a printed wiring board.

Conventionally, a roll coating method has been widely used as a method for forming an insulating layer and a solder resist layer in a method for producing a printed wiring board.
For example, in Patent Document 1, wiring is performed on the front and back surfaces by reducing the coating pressure on the surface of the wiring board with the smaller area ratio of the wiring pattern to be smaller than the coating pressure on the surface of the wiring pattern with the larger area ratio. A technique is disclosed in which an insulating layer or a solder resist layer having a uniform film thickness on the front and back surfaces can be formed even on wiring boards having different pattern area ratios.

JP 2001-144419 A

  However, when a paint is applied to a printed wiring board in which a through hole is formed using a conventional technique as shown in Patent Document 1, a gap may be generated in the through hole. When a thermal stress is applied to a printed wiring board in which such a gap is generated, a nearby wiring layer may be disconnected due to thermal expansion of gas in the gap, and the reliability of the printed wiring board to be manufactured is lacking.

  Therefore, an object of the present invention is to provide a paint coating system, a paint coating apparatus, and a method for manufacturing a printed wiring board that improve the reliability of a printed wiring board to be manufactured.

  The present invention provides a first mesh sheet that covers one surface of a printed wiring board, a first mesh sheet that faces the first mesh sheet, and a surface opposite to the one surface of the printed wiring board. A second mesh sheet that covers the first mesh sheet is provided so as to be movable on the first mesh sheet, and the paint is applied to one surface of the printed wiring board by allowing the paint to penetrate into the first mesh sheet. An application roll and a first application roll that follows the first application roll and is movably provided on the second mesh sheet. By allowing the paint to penetrate into the second mesh sheet, the first application roll And a second application roll for applying the paint to the surface of the printed wiring board opposite to the surface to which the paint is applied.

  The present invention is also a paint application device for applying a paint to both surfaces of a printed wiring board, wherein the main body and the main body are rotatably provided, and the paint is applied to one surface of the printed wiring board. 1 print roll and the printed wiring board arranged in parallel to the first application roll and rotatably provided on the main body, and the paint applied by the first application roll And a second application roll for applying a paint on the surface opposite to the surface of the wiring board.

  In addition, the present invention provides a printed wiring board including a paint application step of applying a paint using a roll coater having a pair of rolls on both sides of a printed wiring board having a wiring pattern and having a through-hole. In the method, in the paint application step, each of the pair of rolls provided so as not to face each other via the printed wiring board is brought into contact with each surface of the printed wiring board while rotating in a predetermined direction. Thus, it is a step of applying the paint to each side of the printed wiring board passing between the pair of rolls.

  Improve the reliability of printed wiring boards to be manufactured.

It is the schematic which shows the external appearance of the coating material coating system which concerns on embodiment of this invention. It is the figure which showed the external appearance of the roll in a present Example. It is the figure which showed the structure of the roll in a present Example. It is the figure which showed the external appearance of the screens 122a and 122b in a present Example. It is the figure which showed the core material in a present Example. It is the figure which showed the double-sided wiring board in a present Example. It is a figure which shows the application | coating method of the insulating resin ink in a present Example. It is a figure which shows the method of apply | coating insulating resin ink to the through hole in a present Example. It is a figure which shows the method of making the double-sided wiring board surface after application | coating of the insulating resin ink in a present Example. It is a figure which shows the double-sided wiring board after application | coating of the insulating resin ink in a present Example.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(Configuration of paint application system and paint application device)
FIG. 1 is a schematic diagram showing an appearance of a paint coating system according to an embodiment of the present invention. The paint coating system of this embodiment includes a system 10 having a roll coater 10a that functions as a paint coating device and a pair of screens 122a and 122b that are attached to the roll coater 10a and sandwich the double-sided wiring board 9. .

  As shown in FIG. 1, the roll coater 10a of the present embodiment includes a pair of rolls 12a and 12b, a pair of squeegees 121a and 121b, and storage units 14a and 14b for storing the insulating resin ink 11, A holding portion 15a that holds the double-sided wiring board 9 sandwiched between the pair of screens 122a and 122b, a roll moving unit 301 that moves the pair of rolls 12a and 12b, and a squeegee moving unit 302 that moves the pair of squeegees 121a and 121b. And have.

  Moreover, the roll part 16a which consists of the roll 12a and the storage part 14a, and the roll part 16b which consists of the roll 12b and the storage part 14b are connected with the drive means (not shown) which moves each in the direction which contacts / separates. .

  The roll moving means 301 of this embodiment is configured so that the roll 12a and the roll 12b are mutually attached to the double-sided wiring board 9 in order to fill the inside of the through holes 4 of the double-sided wiring board 9 with the insulating resin ink 11 so that no gap is generated. Hold and move it at a position that does not face it. That is, the other roll is held so that the roll 12a and the roll 12b exist at a position preceding the one roll in the traveling direction. By adopting such a configuration, in this embodiment, the preceding roll applies the insulating resin ink 11 to one surface of the double-sided wiring board 9 first, so that no gap is formed in the through hole 4. The insulating resin ink 11 can be embedded. The application process of the insulating ink 11 will be described later with reference to FIGS.

  Further, in this embodiment, the insulating resin ink 11 is applied to the double-sided wiring board 9 by moving the pair of rolls 12a and 12b in contact with the pair of screens 122a and 122b sandwiching the double-sided wiring board 9, respectively. Adopt the method to do. Specifically, the screens 122a and 122b of the present embodiment are formed of mesh sheets. Therefore, when the rolls 12a and 12b are brought into contact with the screens 122a and 122b, respectively, and the insulating resin ink 11 is infiltrated into the screens 122a and 122b, the insulating resin ink 11 leaks from each mesh, and the double-sided wiring board 9 Adhere to. With this configuration, the insulating resin ink 11 can be uniformly applied on the surface of the double-sided wiring board 9 without any spots. The configurations of the rolls 12a and 12b and the screens 122a and 122b will be described later with reference to FIGS.

  Further, in this embodiment, after the insulating resin ink 11 is applied on the surface of the double-sided wiring board 9, the squeegee moving means 302 moves the squeegees 121a and 121b on the screens 122a and 122b so that the surface of the double-sided wiring board 9 is on. Can be made. This surface-making process will be described later with reference to FIG.

  Here, the roll moving means 301 and the squeegee moving means 302 of this embodiment can move the pair of rolls 12a and 12b and the pair of squeegees 121a and 121b in a direction substantially perpendicular to the ground surface of the roll coater 10a. To support. Note that the direction substantially orthogonal to the ground contact surface of the roll coater 10a indicates a direction rising against gravity or a direction descending according to gravity, and has a constant inclination with respect to the direction orthogonal to the ground contact surface of the roll coater 10a. It may have. With this configuration, the insulating resin ink 11 can be uniformly applied on the surface of the double-sided wiring board 9 without any spots.

  Further, the roll moving means 301 may be movable in the parallel direction with respect to the double-sided wiring board 9 and fixed at an arbitrary position. In this embodiment, the rolls 12a and 12b are moved by the roll moving means 301 with respect to the double-sided wiring board 9, but the present invention is not limited to this, and the double-sided wiring board 9 may be moved with respect to the rolls 12a and 12b. And

  Next, the pair of rolls 12a and 12b described above will be described with reference to FIGS. FIG. 2 is a view showing the appearance of the rolls 12a and 12b in the present embodiment. FIG. 3 is a diagram illustrating the configuration of the rolls 12a and 12b in the present embodiment.

  As shown in FIGS. 2 and 3, each of the pair of rolls 12a and 12b in this embodiment has a cylindrical shape, and grooves 17a extending in the circumferential direction are formed at a constant pitch (opening) on the outer peripheral portion of the roll 12a. A plurality of grooves 17b extending in the circumferential direction are formed at a constant pitch (corresponding to the opening width) Lb on the outer peripheral portion of the roll 12b.

  Further, the grooves 17a and 17b may be formed so as to extend in a spiral shape in the circumferential direction at a constant pitch (corresponding to the opening width) La and Lb. In the embodiment, for example, as the pair of rolls 12a and 12b, rolls having diameters Ra and Rb of about 110 mm, a material made of ethylene propylene rubber (also referred to as EPT), and a hardness Hv of 60 are used.

  Further, the groove 17a of the roll 12a has a pitch (opening width) La of 120 μm, a depth ta of 60 μm, and an opening angle θa of 90 degrees, and the groove 17b of the roll 12b has a pitch (opening width) Lb of 120 μm and a depth. The thickness tb is 60 μm and the opening angle θb is 90 degrees.

  Further, the shape and dimensions of the grooves 17a and 17b of the rolls 12a and 12b described above are not limited to those in the embodiment. For example, a non-through hole (also referred to as a bottomed hole) is formed on the double-sided wiring board. In this case, it is preferable to make the opening widths La and Lb narrower than the opening diameter of the non-through hole. By making the opening widths La and Lb narrower than the opening diameter of the non-through hole, the air in the non-through hole is easily released when the insulating resin ink 11 is applied to the double-sided wiring board. Can be suppressed.

  Next, the above-described pair of screens 122a and 122b will be described with reference to FIG. FIG. 4 is a diagram showing the appearance of the screens 122a and 122b in the present embodiment. As shown in FIG. 4, the pair of screens 122a and 122b in this embodiment includes mesh sheets 400a and 400b, respectively, and outer frames 401a and 401b for holding the sheets. The outer frames 401a and 401b are provided with engaging portions 402a and 402b, respectively. As a result, the screen 122a and the screen 122b of the present embodiment can be aligned at a fixed position so as not to be displaced from each other.

  The pair of screens 122a and 122b in this embodiment is held in the system 10 by the holding unit 15a in a state where the double-sided wiring board 9 is sandwiched so that the mesh-like 400a and 400b face each other on both sides of the double-sided wiring board 9. The

(Printed wiring board manufacturing method)
Next, examples of the method for producing a printed wiring board of the present invention will be described below. Here, as a method for producing a printed wiring board, a method for producing a printed wiring board having two wiring layers will be described as an example. However, the present invention is not limited to this, and in this embodiment, a paint is applied to both sides. Any printed wiring board may be used.

  In this example, in the step of forming the insulating layer and the solder resist layer using the roll coating method, when the insulating resin ink and the solder resist ink are applied to the wiring board, the through holes provided in the wiring board It is intended to suppress the formation of voids in pores such as IVH (Interstitial Via Hole). Hereafter, each process in a present Example is demonstrated using FIG. 5 thru | or FIG. FIG. 5 is a view showing the core material in the present embodiment. FIG. 6 is a diagram showing a double-sided wiring board in the present embodiment. FIG. 7 is a diagram showing a method of applying an insulating resin ink in this embodiment. FIG. 8 is a diagram showing a method of applying an insulating resin ink to the through hole in this embodiment. FIG. 9 is a diagram showing a method for producing the surface of the double-sided wiring board after applying the insulating resin ink in this embodiment. FIG. 10 is a diagram showing the double-sided wiring board after application of the insulating resin ink in this example.

(First step)
Here, as shown in FIG. 5, for example, the core material 1 which is a resin substrate having a length of 340 mm, a width of 510 mm, and a thickness of 0.4 mm will be described as an example. First, through holes for electrically connecting the copper foils 2a and 2b to predetermined positions of the double-sided copper-clad plate 3 in which the copper foils 2a and 2b having a thickness of 12 μm are bonded to the front and back surfaces of the core material 1, respectively. 4 is formed as a through hole.

  The through hole 4 can be formed by drilling or laser processing. In the example, the through hole 4 having a diameter of about 0.2 mm was formed by drilling. In addition, the thickness of the core material 1 and copper foil 2a, 2b and the diameter of the through hole 4 are not limited to an Example.

(Second step)
Next, first plating layers 5a and 5b made of, for example, copper are formed on the inner surface of the through hole 4 and the surfaces of the copper foils 2a and 2b. The plating layers 5a and 5b are formed, for example, by performing electroless copper plating after performing electroless copper plating.

  After the plating layers 5a and 5b are formed, the wiring layer 6 is formed by selectively etching the plating layer 5a and the copper foil 2a so as to obtain a predetermined wiring pattern 8a by photolithography, and the predetermined wiring pattern 8b is formed. The plating layer 5b and the copper foil 2b are selectively etched to form the second wiring layer 7 so as to be obtained. After the above steps, the double-sided copper-clad board 3 and the double-sided wiring board 9 are formed as shown in FIG.

  Next, an insulating layer is formed on the front and back surfaces of the double-sided wiring board 9 using a roll coating method. The insulating layer is formed by applying an insulating resin ink 11 on both surfaces of the double-sided wiring board 9 by using a roll coater 10a to form resin ink layers 18a and 18b, and the resin ink layers 18a, 18b. 18b includes a curing step in which the insulating layers 20 and 21 are cured.

  The application process is a process mainly intended to fill the through-hole 4 with the insulating resin ink 11 while suppressing the generation of voids in the through-hole 4. Hereinafter, the application process will be described as a third process, and the curing process will be described as a fourth process.

(Third Step): Application Step This application step uses the roll coater 10a to apply the insulating resin ink 11 to both sides of the double-sided wiring board 9, and inside the through holes 4 and the wiring patterns 8a and 8b. The gap is filled with the insulating resin ink 11.

  First, a method for applying the insulating resin ink 11 will be described with reference to FIGS. In this embodiment, the insulating resin ink 11 is adjusted to have a predetermined viscosity, for example, a viscosity in the range of 3 to 6 Pa · s, and then supplied to the storage units 14 a and 14 b.

  Here, when the pair of rolls 12a and 12b are rotated by driving means (not shown), the insulating resin ink 11 stored in the storage portions 14a and 14b enters the grooves 17a and 17b of the pair of rolls 12a and 12b.

  Next, the pair of screens 122a and 122b sandwiching the double-sided wiring board 9 produced in the second step is fixed to the holding portion 15a, and then the double-sided wiring board 9 is sandwiched by the roll moving means 301 as shown in FIG. The insulating resin ink 11 is transferred to the front and back surfaces of the double-sided wiring board 9 by moving the pair of rolls 12a and 12b in contact with the pair of screens 122a and 122b. As described above, the roll 12a and the roll 12b of the present embodiment are provided with the rotation axis shifted with respect to the traveling direction. Specifically, as illustrated in FIG. 8, the roll 12 a is disposed in front of the roll 12 b with respect to the traveling direction. That is, in the coating application process of this embodiment, after the insulating ink 11 is first applied to the surface of the double-sided wiring board 9 that contacts the screen 122a, the screen is on the opposite side of the surface that contacts the screen 122a. The insulating ink 11 is applied to the other surface in contact with the 122b side.

  As shown in FIG. 8, the insulating ink 11 is packed from the surface that contacts the screen 122 a side with respect to the through hole 4 formed in the double-sided wiring board 9. The insulating ink 11 that has flowed into the through hole 4 from one direction can reach the other surface without being blocked. Thus, in this embodiment, the insulating ink 11 can be allowed to flow without forming a gap in the through hole 4.

  After the pair of rolls 12a and 12b have completely passed through the double-sided wiring board 9, as shown in FIG. 9, the pair of screens 122a and 122b sandwiching the double-sided wiring board 9 by the squeegee moving means 302 is used. , 121b are moved while being brought into contact with each other, whereby the front and back surfaces of the double-sided wiring board 9 are made. As a result, in this embodiment, the insulating ink 11 applied to the double-sided wiring board 9 can be spread evenly and the thickness of the insulating ink 11 can be made uniform. After this surface production process is completed, the double-sided wiring board 9 is removed from the holding portion 15a.

  Through the above steps, as shown in FIG. 10, resin ink layers 18 a and 18 b made of insulating resin ink 11 are formed in predetermined regions on both sides of double-sided wiring board 9. With the configuration of the present embodiment, the inside of the through hole 4 and the space between the wiring patterns are filled with the insulating resin ink 11, and the air gap suppression that has been a problem in the past can be realized.

(Fourth Step): Curing Step The double-sided wiring board 9 that has undergone the above-described steps is heated at, for example, 150 ° C. for about 1 hour to evaporate the solvent in the resin ink layers 18a and 18b, and at the same time, 18b is cured to obtain the insulating layer 20.

  When an electronic component or the like is mounted on a printed wiring board having a substantially flat surface, the electronic component can be mounted on the printed wiring board with high accuracy. Specifically, when a position reference pattern is formed on the outer layer of the printed wiring board and the position reference pattern is recognized by an image recognition unit of a mounting machine for mounting electronic components, the surface is a substantially flat surface. Since the recognition image distortion due to the light refraction is small, the recognition accuracy for recognizing the position reference pattern is improved, so that the electronic component can be mounted on the printed wiring board with high accuracy.

  Thus, in the coating material coating system, the coating material coating apparatus, and the printed wiring board manufacturing method in the present embodiment, the reliability of the printed wiring board to be manufactured can be improved. In addition, the reliability of a printed wiring board refers to the reliability under the manufacturing process or implementation status of the printed wiring board. Specifically, for example, the above-described thermosetting process or the printed wiring board is mounted. In the process of receiving heat from a heat-generating component or the like during use of a later electronic device, it is possible to suppress the occurrence of irregularities on the surface of the printed wiring board due to the expansion of the gas present in the gap in the through hole, It prevents that it suppresses that dust bursts and dust is generated.

  The embodiment of the present invention is not limited to the above-described configuration and procedure, and may be modified as long as it does not depart from the gist of the present invention. For example, in the embodiments, each process is described as an independent process, but the present invention is not limited to this. For example, an integrated coating and curing apparatus including a roll coater and a curing (drying) furnace is used. The coating process and the curing process may be performed continuously.

  Moreover, although the present Example demonstrated the manufacturing method of the printed wiring board which consists of a two-layer wiring layer, it is not limited to this. That is, the present embodiment can obtain the same effect even in a method for manufacturing a printed wiring board composed of four or more multilayer wiring layers.

  The present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine a component suitably in different embodiment.

DESCRIPTION OF SYMBOLS 1 ... Core material 2a, 2b ... Copper foil 3 ... Double-sided copper-clad board 4 ... Through-hole IVH,
5a, 5b ... plating layers 6, 7 ... wiring layers 8a, 8b ... wiring pattern 9 ... double-sided wiring board 10 ... paint coating system 10a ... roll coater 11 ... insulating resin ink 12a, 12b ... rolls 14a, 14b ... storage unit 15 ... holding parts 18a, 18b ... resin ink layer 20 ... insulating layers La, Lb ... pitch (opening)
Ra, Rb ... Diameter ta, tb ... Depth θa, θb ... Opening angle

Claims (9)

A first mesh sheet covering one surface of the printed wiring board;
A second mesh sheet disposed opposite to the first mesh sheet and covering a surface opposite to the one surface of the printed wiring board;
A first application roll that is movably provided on the first mesh sheet, and that applies a paint to one surface of the printed wiring board by allowing the paint to penetrate into the first mesh sheet;
The coating material is applied by the first coating roll by following the first coating roll and movably provided on the second mesh sheet, and by allowing the coating material to penetrate into the second mesh sheet. A second application roll for applying a paint to the surface of the printed wiring board opposite to the surface;
A paint application system comprising:   The second application roll is provided so as to be movable in the same direction as the first application roll, and has a rotation shaft located on the rear side in the traveling direction with respect to the rotation axis of the first application roll. The paint application system according to claim 1, wherein the paint application system rotates about the center. A holding unit that holds the printed wiring board covered with the first mesh sheet and the second mesh sheet upright between the first application roll and the second application roll. Prepared,
The paint application system according to claim 2, wherein the first application roll and the second application roll move upward and apply a paint. A first squeegee that is movably provided on the first mesh sheet and that forms one surface of the printed wiring board on which a paint is applied by the first application roll;
The side opposite to the one surface of the printed wiring board, which is provided side by side with the first squeegee and is provided so as to be movable on the second mesh sheet and to which a paint is applied by the second application roll. The paint application system according to claim 3, further comprising a second squeegee for forming the surface of the paint.   The paint application system according to claim 4, wherein the first squeegee and the second squeegee move downward and make a surface of the printed wiring board. A paint application device for applying paint on both sides of a printed wiring board,
The body,
A first application roll that is rotatably provided on the main body, and that applies a paint to one surface of the printed wiring board;
What is the surface of the printed wiring board that is arranged in parallel to the first coating roll via the printed wiring board and is rotatably provided on the main body and to which a paint is applied by the first coating roll. A second application roll for applying paint to the opposite surface;
A paint coating apparatus comprising:   The rotation center position of the first coating roll and the rotation center position of the second coating roll are provided so as not to face each other through the printed wiring board. Paint applicator. A holding unit that holds the printed wiring board upright between the first application roll and the second application roll;
The paint application apparatus according to claim 7, wherein the first application roll and the second application roll move upward and apply a paint. A method for producing a printed wiring board comprising a paint application step of applying a paint using a roll coater having a pair of rolls on both sides of a printed wiring board having a wiring pattern and having a through hole,
The paint application step includes
The pair of rolls provided so as not to face each other via the printed wiring board are brought into contact with each surface of the printed wiring board while rotating in a predetermined direction, so that the print passing between the pair of rolls is made. A method for manufacturing a printed wiring board, comprising the step of applying the paint to each side of the wiring board.

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