JP3711804B2 - Circuit board manufacturing method and mask film mounting hole drilling device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a circuit board manufacturing method and a mask film mounting hole drilling apparatus that can be used in the circuit board manufacturing method.
[0002]
[Prior art]
Conventionally, when a circuit board used as an inner layer material of a multilayer printed wiring board is manufactured by an additive method or a subtractive method, a copper-clad coating is used for forming a resist layer such as a plating resist or an etching resist on a substrate. A thermosetting resin is provided on the surface of a substrate such as a laminated plate, exposed through an exposure mask, and then developed to form a resist layer.
[0003]
In producing an exposure mask used for manufacturing such a circuit board, for example, as shown in FIG. 11, a mask pattern 2 is drawn on a mask film 1 'made of polyethylene or the like, and the mask film 1 is based on this mask pattern. The marking line 21 corresponding to the outer peripheral shape of the desired film shape is marked on the mask film 1 'along the marking line 21 with a cutter or the like, and the mask film 1' is formed on the basis of the cut end surface. A mounting hole 4 'was formed. Then, the mask film 1 'is attached to a film attachment frame on which attachment pins are formed by inserting the attachment pins through the attachment holes 4' to constitute an exposure mask. And the base material was exposed in the state which aligned the exposure mask comprised in this way with respect to the base material.
[0004]
[Problems to be solved by the invention]
However, when the exposure mask is configured as described above, accuracy errors in the process of marking the marking line on the mask film, the process of cutting the mask film, and the process of drilling the mounting holes are accumulated, resulting in the positional accuracy of the mounting holes. The error was large. For this reason, when an exposure mask is configured by attaching a mask film to the attachment frame through the attachment hole, an error in the arrangement position of the mask pattern in the exposure mask also increases. When the substrate is exposed after alignment, the formation accuracy of the resist layer formed on the substrate deteriorates, and the formation accuracy of the circuit finally formed on the substrate deteriorates. This deterioration in circuit formation accuracy is particularly necessary when the circuit is formed on both sides of the substrate, and the exposure mask placed on the other side of the substrate must be aligned with the exposure mask placed on the one side of the substrate. There is a problem that causes a positional shift of the circuit with respect to the substrate.
[0005]
The present invention has been made in view of the above points, and improves the positional accuracy of the mask pattern in the exposure mask to improve the formation accuracy of the resist layer formed by exposure, and the circuit formed on the substrate. It is an object of the present invention to provide a circuit board manufacturing method capable of improving the forming accuracy, and a mask film mounting hole drilling device usable in the circuit board manufacturing method.
[0006]
[Means for Solving the Problems]
In the method for manufacturing a circuit board according to claim 1 of the present invention, when the substrate B is subjected to an additive method or a subtractive method to form a circuit, the substrate B provided with a photosensitive material is exposed and developed to form a resist. In the manufacturing method of the circuit board to be formed, the mask pattern 2 and the reference mark 3 are drawn on the mask film 1, the attachment hole 4 is formed in the mask film 1 with the reference mark 3 as a reference, and the film attachment frame 5 is formed. The mask film 1 is mounted on the film mounting frame 5 by inserting the mounting holes 4 through the mounting pins 7 to form the exposure mask A, and the exposure mask is formed on the circuit forming surface side of the base material B provided with the photosensitive material. A is arranged, and the base material B is exposed through the exposure mask A.
[0007]
The invention of claim 2 is characterized in that, in addition to the configuration of claim 1, the light shielding portion 6 is formed in an area where the mask pattern 2 and the reference mark 3 of the mask film 1 are not drawn.
[0008]
According to a third aspect of the present invention, there is provided an attachment hole drilling device for a mask film 1 having a work table 9 on which the mask film 1 is placed and a reference formed on the mask film 1 placed on the work table 9. Detection means for detecting the mark 3, display means for displaying the image 14 of the reference mark 3 detected by the detection means, and drilling for making the attachment hole 4 in the mask film 1 placed on the work table 9 Means.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
[0010]
As shown in FIG. 4, the mask film 1 is produced by drawing a mask pattern 2 and a reference mark 3 on a film such as a polyethylene film. The mask pattern 2 and the reference mark 3 can be drawn with a laser plotter or the like.
[0011]
Here, the reference mark 3 is drawn simultaneously with the mask pattern 2, and the drawing position of the reference mark 3 is set with reference to the drawing position of the mask pattern 2. Specifically, the laser plotter is numerically controlled based on the data of the mask pattern 2 designed using, for example, CAD and the like and the data of the reference mark 3 with respect to the arrangement position of the mask pattern 2 defined in the XY coordinate axis system. The mask pattern 2 and the reference mark 3 are drawn.
[0012]
At least two fiducial marks 3 are formed in a region on the mask film 1 where the mask pattern 2 is not formed. For example, the reference mark 3 can be formed in the vicinity of each of a pair of opposing corners among the four corners of the mask film 1 formed in a rectangular shape in plan view. It is formed on a straight line passing through the center and at a position equidistant from the center of the mask film 1.
[0013]
As shown in FIG. 5, the mask film 1 has a plurality (two in the illustrated example) of mounting holes 4 in an area where the mask pattern 2 is not formed with reference to the position of the reference mark 3. Drilled.
[0014]
As schematically shown in FIG. 1, the mask film 1 formed in this way is detected by an image detector 10 and a predetermined image with reference to the image of the reference mark 3 formed by the image detection device 12. The mounting hole 4 is drilled by the drilling tool 13 in this state. Then, the mask film 1 is attached to the film attachment frame 5 by inserting the attachment pins 7 of the film attachment frame 5 through the attachment holes 4 to constitute the exposure mask A. This will be specifically described below.
[0015]
FIG. 2 shows a mask film mounting hole drilling device (hereinafter sometimes abbreviated as “piercing device”) for drilling the mounting hole 4 in the mask film 1. In this drilling apparatus, a work table 9 on which the mask film 1 is disposed is disposed. As a detection means for detecting the reference mark 3, an image detector such as a CCD camera or the like for each reference mark 3 is recognized above the work table 9 and recognizes an image 14 to be detected with a gradation of a predetermined gradation. 10 is disposed, and in the illustrated example, a pair of image detectors 10a and 10b are disposed. In addition, an image recognition device 12 that constitutes an image 14 is provided by binarizing the detection results detected by the image detectors 10a and 10b with a predetermined gray level with a predetermined threshold value. In addition, a monitor 11 that displays an image 14 configured by the image recognition device 12 is provided. The monitor 11 is provided for each of the image detectors 10a and 10b. In the present embodiment, two monitors 11a and 11b are provided. A drilling tool 13 having a pair of cylindrical punches 13a for drilling the mounting holes 4 in the mask film 1 disposed on the work table 9 is disposed. Here, the punch 13a passes through the midpoint of the line segment 18 connecting the reference points 17 set in the field of view of the image detectors 10a and 10b, and the reference line 19 orthogonal to the straight line 20 connecting the pair of punches 13a. On both sides, they are arranged at equidistant positions from the reference line 19. The interval between the punches 13a and 13a is, for example, 350 mm, and the diameter of each punch 13a is 5 mm. The monitor 11 displays a reference line for indicating the reference point 17 set in the field of view of the image detector 10. That is, a cross-shaped reference line made up of vertical lines 20a and horizontal lines 20b is displayed on the monitor 11, and each reference set in the field of view of each image detector 10a, 10b at the intersection of the vertical lines 20a and 20b. Point 17 is shown. The reference point 17 is set at the center position of the reference mark 3 in a state where the mask film 1 is disposed at a predetermined position on the work table 9.
[0016]
In making the mounting hole 4 in the mask film 1 using the thus configured punching device, the operator first looks at the monitor 11 while viewing the monitor 11, and the image detectors 10a, The mask film 1 is arranged on the work table 9 so as to be arranged in the visual field of 10b. Then, the position of the mask film 1 on the work table 9 is manually adjusted while observing the positional relationship between the reference line and the reference mark 3 on the monitor 11, and each image detector corresponding to the center of each reference mark 3. It is arranged at each reference point 17 in the visual field of 10a, 10b.
[0017]
Further, when an error occurs in the arrangement position of the reference mark 3 due to the extension of the mask film 1, the arrangement relationship between the arrangement position of the reference mark 3 and the reference point 17 is adjusted according to a predetermined rule. Thus, the mask film 1 is arranged at a predetermined position. That is, for example, the positions of the centers of the reference marks 3 displayed on the monitors 11 are both arranged outside the vertical line 20a and arranged outside the horizontal line 20b. Both of the center arrangement positions are arranged inside the vertical line 20a and inside the horizontal line 20b, and the center arrangement position of the reference mark 3 at this time is the vertical line 20a and the horizontal line. It is arranged at a position equidistant from 20b. In this way, the mask pattern 2 of the mask film 1 is predetermined so that the line segment connecting the reference marks 3 of the mask film 1 and the line segment connecting the reference points 17 coincide with each other and the midpoints thereof coincide with each other. It is arranged at a position, and the arrangement position of the mask pattern 2 of the mask film 1 on the work table 9 can always be arranged at a predetermined position with reference to the reference mark 3.
[0018]
When the mask film 1 is arranged on the work table 9 as described above so that the mask pattern 2 is arranged at a predetermined arrangement position, the punching tool 13 is operated to form the mask film 1 on the mask film 1 with the punch 13a. A mounting hole 4 is formed.
[0019]
When the attachment holes 4 are formed in the mask film 1 in this manner, the attachment holes 4 are formed so as to have a predetermined positional relationship with respect to the mask pattern 2, and the formation position accuracy of the attachment holes 4 is high. Thus, the positional accuracy of the arrangement position of the mask pattern 2 with respect to the exposure device with respect to the base material B in the exposure process can be improved, and the circuit formation accuracy with respect to the base material B can be improved. In particular, when the front and back mask films 1 are formed to expose both the front and back surfaces of the base material B, the arrangement relationship of the mounting holes 4 with respect to the mask pattern 2 in each mask film 1 can be accurately aligned. As will be described later, when both front and back surfaces of the base material B are exposed, the mask pattern 2 on the front and back surfaces when the mask pattern 2 is arranged on both front and back surfaces of the base material B can be accurately aligned. The positional deviation with respect to the base material of the circuit formed in the front and back of this can be reduced.
[0020]
Moreover, said punching apparatus can also be comprised so that alignment of the arrangement position of the mask film 1 can be performed by automatic control. In this case, the work table 9 is formed as an XY table provided with an actuator mechanism or the like that moves the work table 9 in the XY biaxial directions perpendicular to each other on a horizontal plane. Further, a control unit that detects the positional deviation of the reference mark 3 from the image 14 of the reference mark 3 detected by the image detector 10 and moves the work table 9 by controlling the actuator mechanism by numerical control based on the detection result. Is provided. To illustrate a specific control method, the operator first places the mask film 1 on the work table 9 so that the reference mark 3 is arranged in the field of view of the image detector 10 while viewing the monitor 11. The image 14 of the reference mark 3 constituted by the image recognition device 12 is input to the control unit. At this time, the control unit and the pattern 14 of the mask film 1 previously input to the control unit. The position of the center of the mask pattern 2 is derived by querying the shape. Next, the control unit slides the work table 9 based on the arrangement positions of the two mask patterns 2, and arranges the mask film 1 at a predetermined position. At this time, the control unit sets, for example, an XY orthogonal coordinate axis on the work table 9 and coordinates of the center of the reference mark 3 with the reference point 17 in the field of view of the image detector 10a detecting one reference mark 3 as the origin. (X1, y1) and the coordinates (x2, y2) of the center of the reference mark 3 with the reference point 17 in the field of view of the image detector 10b that detects the other reference mark 3 as the origin are derived. The slide of the work table 9 is moved (x1 + x2) / 2 in the X-axis direction and (y1 + y2) / 2 in the Y-axis direction. In this way, the midpoint of the line segment connecting the reference marks 10 of the mask film 1 is arranged at the midpoint of the line segment connecting the reference points 17 and the mask pattern 2 of the mask film 1 is arranged at a predetermined position. Is done.
[0021]
When the mask film 1 is arranged on the work table 9 as described above so that the mask pattern 2 is arranged at a predetermined arrangement position, the punching tool 13 is operated to form the mask film 1 on the mask film 1 with the punch 13a. A mounting hole 4 is formed.
[0022]
Thus, when the alignment of the arrangement position of the mask film 1 is performed by automatic control, the mounting hole 4 is formed to have a predetermined positional relationship with respect to the mask pattern 2 by automatic control. The formation position accuracy is high, and the work efficiency in the step of drilling the mounting hole 4 is high.
[0023]
FIG. 7 shows the film mounting frame 5. The film mounting frame 5 is composed of an outer frame 5a and an inner plate 5b.
[0024]
The outer frame 5a is formed as a rectangular frame surrounding an opening formed inside thereof, and is formed of metal. The inner plate 5b is made of a material that transmits light used in the exposure process, and can be made of a transparent plate material such as an acrylic plate. The inner plate 5b is disposed so as to close the opening inside the outer frame 5a. Here, the inner plate 5b is formed in a rectangular shape having substantially the same plan view shape as that of the mask film 1, and a pair of mounting pins 7 corresponding to the mounting holes 4 of the mask film 1 are integrally projected on one surface thereof. In addition, an exhaust groove 5c opening on one surface side of the inner plate 5b is provided in a recessed manner. The exhaust groove 5c is formed so as to surround the arrangement position of the mask pattern 2 in a state where the mask film 1 is arranged on the inner plate 5b, and the exhaust groove 5c communicates with the outer side of the outer frame 5a. A groove 5d is formed.
[0025]
In forming the exposure mask A by attaching the mask film 1 to the film attachment frame 5, first, the attachment pins 7 of the film attachment frame 5 are inserted into the attachment holes 4 of the mask film 1, as shown in FIGS. Then, the mask film 1 is arranged on one surface of the inner plate 5 b of the film mounting frame 5. In this state, the air in the exhaust groove 5c is sucked through the introduction groove 5d to exhaust the air between the mask film 1 and the inner plate 5b, thereby bringing the mask film 1 and the inner plate 5b into close contact with each other. Furthermore, the mask film 1 is fixed to the film mounting frame 5 by adhering the tape 8 to a portion where the mask film 1 and the outer frame 5a are adjacent to each other.
[0026]
In the exposure mask A configured in this way, the formation position of the mask pattern 2 and the formation position of the attachment hole 4 in the mask film 1 are accurately formed in a predetermined positional relationship. The arrangement position of the mask pattern 2 with respect to the pin 7 is also arranged with high accuracy in a predetermined positional relationship. That is, the mask pattern 2 is accurately arranged at a predetermined position of the exposure mask A.
[0027]
A circuit board is formed by applying an additive method or a subtractive method to a base material B provided with a conductor layer on the outside of an insulating layer such as a copper-clad laminate, and a circuit board such as an inner layer board for producing a multilayer printed wiring board In the case of forming, a plating resist or an etching resist is formed on the base B by exposing and developing the base B provided with the photosensitive material using the exposure mask A configured as described above. be able to.
[0028]
The exposure of the photosensitive material provided on the base material B can be performed, for example, as shown in FIG. That is, a long copper-clad laminate is fed out to an exposure device 15 equipped with an exposure device such as an ultraviolet irradiation device and placed in a predetermined arrangement state. Here, a photosensitive material is provided on the circuit forming surface of the base material B by attaching a dry film made of an ultraviolet curable resin. On the other hand, the exposure mask A is arranged on the circuit forming surface side of the base material B, and is fixed by a clamp 16 such as a mechanical clamp provided in the exposure apparatus 15. At this time, the exposure mask A is arranged at a predetermined position with respect to the base material B so that the straight line connecting the pair of mounting pins 7 and the direction in which the base material B is fed out are parallel.
[0029]
Here, when forming a circuit on both surfaces of the base material B, as shown in FIG. In this case, each exposure mask A is arranged by aligning the formation position of the attachment pin 7 in one exposure mask A and the formation position of the attachment pin 7 in the other exposure mask A. At this time, as described above, in each exposure mask A arranged on both surfaces, the formation positions of the attachment holes 4 with respect to the mask pattern 2 in the mask film 1 are accurately aligned. Are arranged without misalignment, exposure on the front and back of the substrate B can be performed without misalignment, and misalignment between circuits formed on the front and back of the substrate B can be prevented.
[0030]
In this state, the photosensitive material of the substrate B is exposed by irradiating the circuit forming surface of the substrate B with ultraviolet rays or the like through the exposure mask A from the exposure device. When the exposure is completed, a predetermined amount of the base material B is fed out to update the region used for the exposure of the base material B, and repeated exposure is performed.
[0031]
Here, when the mask pattern 2 and the reference mark 3 are drawn in the areas where the mask pattern 2 is not formed on both ends of the mask film 1, the light shielding portion 6 is simultaneously drawn by the laser plotter as shown in FIG. 6. In this way, ultraviolet rays or the like irradiated from the exposure device are prevented from passing through the light-shielding portion 6, and when the exposure mask A is arranged with respect to the substrate B, the feeding direction of the substrate B, that is, the substrate If the light-shielding portions 6 are arranged at both ends along the longitudinal direction of B, ultraviolet rays and the like are more forward and backward in the feeding direction of the base material B than the mask pattern 2 when the photosensitive material is exposed. In this case, it is possible to prevent the base material B from being irradiated. When ultraviolet rays are irradiated to the front side and the rear side in the feeding direction of the base material B at the time of exposure, it becomes impossible to form a circuit at that portion, but when the mask film 1 having the light shielding portion 6 is used. It is possible to prevent the generation of the area where the circuit cannot be formed, and the circuit can be formed using the area on the base material B without waste. It is possible to increase the amount of circuit board to be produced.
[0032]
The base material B that has undergone this exposure step is developed by, for example, processing with a developer made of sodium carbonate or the like to form a resist.
[0033]
Next, when a circuit is formed by a subtractive method, this resist is used as an etching resist, and after removing the conductor layer in a portion where the resist is not formed by an etching process, the resist is peeled off. Further, the circuit board is obtained by cutting the base material B into a desired dimension.
[0034]
When the circuit is formed by an additive method, this resist is used as a plating resist, and after a conductor layer is formed by an electroplating method or the like on a portion where the resist is not formed, the resist is peeled off. Then, a soft etching process is performed on the circuit formation surface to form a circuit. Furthermore, a circuit board is obtained by cutting the base material B into a desired dimension.
[0035]
As described above, in the method for manufacturing a circuit board according to the present invention, the mask pattern 2 can be accurately placed on the base material B when performing an exposure process for forming an etching resist or a plating resist for forming a circuit. And circuit formation accuracy can be improved.
[0036]
【The invention's effect】
As described above, in the method for producing a circuit board according to claim 1 of the present invention, when the circuit is formed by subjecting the base material to the additive method or the subtractive method, the base material provided with the photosensitive material is exposed and developed. In the circuit board manufacturing method for resist formation, a mask pattern and a reference mark are drawn on the mask film, a mounting hole is formed in the mask film with reference to the reference mark, and a mounting pin formed on the film mounting frame is provided. An exposure mask is configured by attaching a mask film to a film mounting frame by inserting an attachment hole, and an exposure mask is disposed on the circuit forming surface side of the substrate on which the photosensitive material is provided, and the substrate is interposed through the exposure mask. Can improve the positional accuracy of the position of the mask film in the exposure mask, and can be used for etching resist and plating for circuit formation on the substrate. In forming by exposure and development processes to resist, in which it is possible to improve the formation accuracy of the resist. Therefore, circuit formation accuracy can be improved.
[0037]
In addition to the structure of claim 1, the invention of claim 2 forms a light-shielding portion in an area where the mask pattern and reference mark of the mask film are not drawn, and exposes the substrate through the exposure mask. In doing so, it is possible to prevent the region where the resist is not formed on the base material from being exposed by the light-shielding portion, and particularly when forming a circuit along the long direction of the long base material. It is possible to prevent the occurrence of areas where circuits cannot be formed at both ends in the longitudinal direction of the upper circuit formation area, and it is possible to perform circuit formation using the area on the substrate without waste.
[0038]
According to a third aspect of the present invention, there is provided a mask film mounting hole drilling device for detecting a work table on which a mask film is placed and a reference mark formed on the mask film placed on the work table. Means, a display means for displaying an image of the reference mark detected by the detection means, and a punching means for drilling a mounting hole in the mask film placed on the work table. The mask film is arranged at a predetermined position on the work table with reference to the reference mark displayed on the means, and in this state, the mounting hole can be drilled in the mask film by the drilling means, and the mask film is formed. The mounting holes can be formed with a predetermined positional relationship with a high positional accuracy with respect to the reference mark.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing an example of a circuit board manufacturing method according to the present invention.
FIG. 2 shows an outline of a mask film mounting hole drilling device according to the present invention, wherein (a) is a plan view showing a work table, an image detection device, and a drilling tool, and (b) is a pair of tools. It is a front view which shows a display monitor.
FIG. 3 is a schematic plan view showing a positional relationship between a base material and an exposure mask in an exposure process.
FIG. 4 is a plan view showing an example of a mask film.
FIG. 5 is a plan view showing a state in which a mounting hole for the mask film is formed.
FIG. 6 is a plan view showing another example of a mask film.
FIG. 7 is a plan view showing an example of a film mounting frame.
FIG. 8 is a plan view showing an example of an exposure mask.
FIG. 9 is a sectional view showing the same exposure mask.
FIG. 10 is a cross-sectional view showing a state in which exposure masks are arranged on both surfaces of a substrate.
FIG. 11 is a plan view showing a conventional technique.
[Explanation of symbols]
A Exposure mask B Base material 1 Mask film 2 Mask pattern 3 Reference mark 4 Mounting hole 5 Film mounting frame 6 Shading part 7 Mounting pin

Claims (3)

In a circuit board manufacturing method in which a substrate provided with a photosensitive material is exposed and developed to form a resist when performing circuit formation by applying an additive method or a subtractive method to the substrate, the mask pattern and the reference are applied to the mask film. The mask film is attached to the film mounting frame by drawing a mark, making a mounting hole in the mask film with reference to the reference mark, and inserting the mounting hole into a mounting pin formed in the film mounting frame. A method of manufacturing a circuit board, comprising: arranging an exposure mask on a circuit forming surface side of a base material provided with a photosensitive material, and exposing the base material through the exposure mask. The method for manufacturing a circuit board according to claim 1, wherein the light shielding portion is formed in an area where the mask pattern and the reference mark of the mask film are not drawn. A work table on which the mask film is placed, a detection means for detecting a reference mark formed on the mask film placed on the work table, and a display means for displaying an image of the reference mark detected by the detection means; A mask film mounting hole drilling apparatus comprising: a drilling means for drilling a mounting hole in a mask film placed on a work table.

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