JP6861487B2 - Coating device and ink coating method - Google Patents

Description

The present invention relates to a coating apparatus and an ink coating method.

Conventionally, a circuit board in which a patterned solder resist (permanent protective film) is formed on a surface (coated surface) of a substrate on which a conductor circuit is formed is widely used. In the manufacture of this type of circuit board, when forming a solder resist on the coated surface of the substrate, it is known that an ink made of a photosensitive resin is applied to the coated surface of the substrate by a roll coating method to form a film. (See, for example, Patent Documents 1 and 2).
In the roll coating method, the doctor bar is pressed against the peripheral surface of the rotating coating roll to apply ink to the peripheral surface of the coating roll to a predetermined thickness, and the coating roll is further pressed against the coating surface of the substrate to obtain ink. Is formed in the form of a film on the coated surface of the substrate.

Japanese Unexamined Patent Publication No. 7-193361 Japanese Unexamined Patent Publication No. 7-176855

By the way, in recent years, a circuit board co-operation design has been considered in which a plurality of types of circuit boards are manufactured using the same substrate so that the portion where the substrate is discarded is reduced in the manufacture of the circuit board. However, in the conventional roll coating method, the ink can be applied only to the coated surface of the same substrate with the same film thickness. Therefore, there is a problem that a plurality of types of circuit boards having different film thickness specifications of the solder resist (ink) cannot be manufactured on the same substrate.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a coating device and an ink coating method capable of manufacturing a plurality of types of circuit boards having different film thicknesses of solder resist on the same substrate. And.

First aspect of the present invention, the applicator roll to a coating apparatus for applying ink comprising a photosensitive resin on the coated surface of the substrate, have a circumferential surface facing the coating surface, is elastically deformable elastic body The doctor bar pressed against the peripheral surface of the coating roll, the roll rotation driving unit that rotationally drives the coating roll, and the doctor bar that drives the doctor bar to change the amount of the doctor bar pushed against the peripheral surface of the coating roll. A doctor bar drive unit for driving, a roll push drive unit that drives the coating roll to change the pushing amount of the coating roll with respect to the coating surface, a roll rotation drive unit, the doctor bar drive unit, and the roll push drive unit. by controlling the operation of at least the roll pusher driving portion of the push-in amount of the doctor bar against the peripheral surface of the coating roll, the rotational speed of the applicator roll, at least the one of the push-in amount of the coating roll with respect to the coated surface The coating device includes a control unit that changes the film thickness of the ink on the coating surface by changing the pressing amount of the coating roll.

The coating apparatus, associates the thickness of the ink on the coating surface, push-in amount of the doctor bar, the rotational speed of the applicator roll, and at least push-in amount of the coating roll of the push-in amount of the coating roll The control unit includes a storage unit in which the control information is stored, and the control unit includes the roll rotation drive unit, the doctor bar drive unit, and the roll push drive unit based on the control information stored in the storage unit. Of these, at least the operation of the roll pushing drive unit may be controlled.

The coating device includes a transfer unit that relatively transfers the coating roll and the substrate along the coating surface so that the coating roll rolls on the coating surface, and the coating roll in the transfer direction by the transfer unit. A substrate position detecting unit for detecting the position of the substrate with respect to the substrate is provided, and the storage unit includes a position of the substrate in the transfer direction and a plurality of target values of the film thickness of the ink on the coated surface. The associated target information is stored, and the control unit uses the roll rotation drive unit, based on the target value corresponding to the position of the substrate detected by the substrate position detection unit and the control information. Of the doctor bar drive unit and the roll push-in drive unit, at least the operation of the roll push-in drive unit may be controlled.

The substrate position detection unit is detected by a pressing detection sensor that detects the pressing of the coating roll against the substrate, a speed detection sensor that detects the rotation speed of the coating roll rolling on the coating surface, and the pressing detection sensor. Based on the detection information, the coating start position where the ink coating is started is set on the coating surface, and based on the rotation speed of the coating roll detected by the speed detection sensor with the coating start position as a reference. A position calculation unit for continuously calculating the position of the substrate in the transfer direction may be provided.

In the second aspect of the present invention, the ink is defined by scraping the ink applied to the peripheral surface of the rotating coating roll, which is made of a photosensitive resin, with a doctor bar pressed against the peripheral surface of the coating roll. This is an ink coating method for applying the ink to the coating surface by pressing the rotating coating roll into the coating surface of the substrate, which is applied to the peripheral surface of the coating roll with the thickness of the above . It is an elastic body that can be elastically deformed, and at least the pushing amount of the coating roll among the pushing amount of the doctor bar with respect to the peripheral surface of the coating roll, the rotation speed of the coating roll, and the pushing amount of the coating roll with respect to the coating surface is set. This is an ink coating method that changes the film thickness of the ink on the coating surface by changing the ink.

According to the present invention, the coating is applied to the coating surface of the substrate by changing at least one of the pressing amount of the doctor bar with respect to the coating roll, the rotation speed of the coating roll, and the pressing amount of the coating roll with respect to the coating surface of one substrate. The film thickness of the ink to be produced can be changed. Therefore, it is possible to manufacture a plurality of types of circuit boards having different solder resist film thicknesses on the same substrate. As a result, it is possible to reduce the working time required for manufacturing a plurality of types of circuit boards and to reduce the amount of materials used for the substrate and the solder resist.

It is a front view which shows the outline of the coating apparatus which concerns on one Embodiment of this invention. It is a schematic side sectional view of the coating apparatus viewed from the axial direction of the coating roll. It is a functional block diagram of the coating apparatus. It is a graph which shows the relationship between the pushing amount of the doctor bar in the coating apparatus, and the film thickness of the ink applied to the coating surface of a substrate. It is a graph which shows the relationship between the rotation speed of the coating roll in the coating apparatus, and the film thickness of the ink applied to the coating surface of a substrate. It is a graph which shows the relationship between the pushing amount of the coating roll in the coating apparatus, and the film thickness of the ink applied to the coating surface of a substrate. It is a top view of the substrate which shows an example of a plurality of regions on the coating surface of a substrate. It is a table which shows an example of the target information which associated the plurality of regions of the coating surface with the target value of the ink film thickness corresponding to each region. It is a figure for demonstrating the coating start position on a substrate. It is a figure which shows one process of the ink application method which concerns on one Embodiment of this invention. It is a figure which shows one process of the coating method. It is a figure which shows one process of the coating method. It is a figure which shows one process of the coating method. It is a graph which shows the content of the coating method of Example 1. FIG. It is a graph which shows the content of the coating method of Example 2. It is a graph which shows the content of the coating method of Example 3. It is a graph which shows the content of the coating method of Example 4. It is a graph which shows the content of the coating method of Example 5. It is a graph which shows the content of the coating method of Example 6. It is a graph which shows the content of the coating method of Example 7. It is a table which shows the result of having investigated the error of the measured film thickness with respect to the target film thickness of the ink with respect to the film thickness of the ink applied by the coating method of each Example.

Hereinafter, the details of the present invention will be described based on the embodiments.
As shown in FIGS. 1 to 3, the coating device 1 according to the present embodiment is a device that coats the coating surface 3 of the substrate 2 with the ink 4 made of a photosensitive resin.
The target substrate 2 may be arbitrarily configured as long as a conductor circuit is formed on at least the coated surface 3. The substrate 2 of the present embodiment has a conductor circuit formed on both surfaces (both coated surfaces 3 and 3), and a solder resist is formed on both coated surfaces 3 and 3 to form an FCBGA (Flip Chip Ball Grid Array). It constitutes a double-sided printed circuit board in which bumps appear on both sides, such as a board.
The coating device 1 includes a coating roll 11, a doctor bar 12, a roll rotation drive unit 13, a doctor bar drive unit 14, a roll push drive unit 15, a transfer unit 16, and a control unit 17.

The coating roll 11 is formed in a columnar shape and has a peripheral surface 111 facing the coating surface 3 of the substrate 2. The ink 4 is applied to the peripheral surface 111 of the coating roll 11. The coating roll 11 is attached to the base (not shown) of the coating device 1 so that the coating roll 11 can rotate about the axis L1 and the peripheral surface 111 of the coating roll 11 can be pressed against the coating surface 3 of the substrate 2. It is provided. Coating roll 11 is elastically deformable elastic body as such c Retangomu.
In the present embodiment, the coating rolls 11 face both coating surfaces 3 and 3 of the substrate 2 and are spaced apart in the thickness direction of the substrate 2 so that the substrate 2 can be sandwiched from the thickness direction thereof. It is arranged in pairs.

The pair of coating rolls 11 and 11 are provided on the base of the coating device 1 so as to move in a direction in which they are relatively approached or separated from each other. As a result, the peripheral surface 111 of each coating roll 11 can be pressed against each coating surface 3 of the substrate 2. The pair of coating rolls 11 and 11 may be provided on the base of the coating device 1 so as to be movable in the direction of approaching or moving away from each coating surface 3 of the substrate 2, for example. In the present embodiment, one of the pair of coating rolls 11 and 11 (the coating roll 11 on the right side in FIG. 2) is placed on the base of the coating device 1 so as to approach or move away from the coating surface 3 of the substrate 2. On the other hand, it is provided so that it can be moved. The other coating roll 11 is provided so as not to move with respect to the base of the coating device 1.

The doctor bar 12 is formed in a substantially flat plate shape and is pressed against the peripheral surface 111 of each coating roll 11. More specifically, the doctor bar 12 is arranged so that the coating roll 11 is located between the doctor bar 12 and the substrate 2. As shown in FIG. 2, the lower end of the doctor bar 12 in the vertical direction (vertical direction in FIGS. 1 and 2) when viewed from the axis L1 direction of the coating roll 11 is located closest to the peripheral surface 111 of the coating roll 11. To do. The lower end of the doctor bar 12 is pressed against the peripheral surface 111 of the coating roll 11. The doctor bar 12 extends away from the peripheral surface 111 of the coating roll 11 from the lower end to the upper end. The doctor bar 12 is movable with respect to the coating roll 11 so that the pressing pressure against the coating roll 11 changes.
A storage space V1 for storing the ink 4 for supplying the ink 4 to the peripheral surface 111 of the coating roll 11 may be provided separately, for example, but in the present embodiment, there is a gap between the coating roll 11 and the doctor bar 12. It is formed.

In this embodiment, each coating roll 11 and the doctor bar 12 corresponding to each coating roll 11 are supported by the same support 18. The support 18 supports both ends of the coating roll 11 and the doctor bar 12 in the axis L1 direction of the coating roll 11.
In the present embodiment, one support 18 supporting the one coating roll 11 and the doctor bar 12 (right side in FIG. 2) so that one coating roll 11 approaches or separates from the coating surface 3 of the substrate 2. Support 18) is movable with respect to the base of the coating device 1. The other support 18 that supports the other coating roll 11 and the doctor bar 12 is fixed to the base of the coating device 1.

The roll rotation drive unit 13 rotates and drives each coating roll 11. An arbitrary motor may be adopted for the roll rotation drive unit 13, but in the present embodiment, a pulse motor that operates by an input pulse signal is adopted so that the rotation angle and rotation speed of the coating roll 11 can be grasped. ing.

The doctor bar driving unit 14 drives the doctor bar 12 to press the doctor bar 12 against the peripheral surface 111 of the coating roll 11 and to release the doctor bar 12. Further, the doctor bar driving unit 14 drives the doctor bar 12 to change the pushing amount of the doctor bar 12 (particularly the lower end portion of the doctor bar 12) with respect to each coating roll 11.
Here, the pushing amount of the doctor bar 12 is the moving length that the doctor bar 12 moves with respect to the coating roll 11 so that the pressing pressure against the coating roll 11 changes. The pushing amount of the doctor bar 12 is related to the film thickness of the ink 4 remaining on the peripheral surface 111 of the coating roll 11 after the ink 4 applied to the peripheral surface 111 of the coating roll 11 is scraped off by the doctor bar 12. For example, when the pushing amount of the doctor bar 12 increases, the film thickness of the ink 4 on the peripheral surface 111 of the coating roll 11 decreases.
An arbitrary motor may be adopted for the doctor bar drive unit 14, but in the present embodiment, a pulse motor that operates by an input pulse signal is adopted so that the pushing amount of the doctor bar 12 can be grasped.

The roll pushing drive unit 15 drives the coating roll 11 to change the pushing amount of the coating roll 11 with respect to the coating surface 3. More specifically, the roll pushing drive unit 15 moves the coating roll 11 in a direction of approaching or moving away from the coating surface 3 of the substrate 2. The roll pushing drive unit 15 may drive, for example, a pair of coating rolls 11 and 11, respectively, but in the present embodiment, only one coating roll 11 is driven. Further, in the roll pushing drive unit 15 of the present embodiment, the coating roll 11 approaches the coating unit 18 and the coating unit 10 including the coating roll 11 supported by the support 18 and the doctor bar 12 with respect to the coating surface 3. It is configured as a unit drive unit 19 that moves in a direction of moving away from each other.
An arbitrary motor may be adopted for the unit drive unit 19 (roll push drive unit 15), but in the present embodiment, a pulse motor that operates by an input pulse signal so that the push amount of the coating roll 11 can be grasped. Has been adopted.

The transfer unit 16 relatively moves the coating roll 11 and the substrate 2 along the coating surface 3 of the substrate 2. The relative moving speed of the coating roll 11 and the substrate 2 by the transfer unit 16 will be described later so that the coating roll 11 rolls on the coating surface 3 of the substrate 2 at least when the ink 4 is applied to the coating surface 3. It is controlled by the control unit 17 so as to correspond to the rotation speed of the coating roll 11.
The transfer unit 16 may be, for example, a roll transfer unit that transfers the coating roll 11, but in the present embodiment, it is a substrate transfer unit 20 that transfers the substrate 2.

In the present embodiment, the substrate transfer unit 20 transfers the substrate 2 so as to feed the substrate 2 between the pair of coating rolls 11 and 11 and pull out the substrate 2 from between the pair of coating rolls 11 and 11. To do.
More specifically, the substrate transfer unit 20 includes a holding unit 21 for holding the substrate 2 and a transfer driving unit 22 for moving the holding unit 21.
The holding portion 21 holds the end portion of the substrate 2 so as to suspend the substrate 2, and is movable vertically (vertically) with respect to the base of the coating device 1.
The transfer drive unit 22 moves the holding unit 21 up and down so that the substrate 2 held by the holding unit 21 passes between the pair of coating rolls 11 and 11. A pulse motor is used as the drive system of the transfer drive unit 22, and the position of the substrate 2 is grasped by cumulatively totaling the pulse amounts instructed by the control unit 17 described later to the motor. In this embodiment, a pulse motor is used, but any drive device that can instruct operations with at least a digital amount is sufficient, and for example, a linear slider or the like can be used.

The control unit 17 controls the operation of at least one of the roll rotation drive unit 13, the doctor bar drive unit 14, and the roll push drive unit 15, and the amount of push of the doctor bar 12 with respect to the peripheral surface 111 of the coating roll 11 and the coating roll 11 At least one of the rotation speed of the coating roll 11 and the pushing amount of the coating roll 11 with respect to the coating surface 3 of the substrate 2 is changed.

The coating device 1 of the present embodiment includes a storage unit 23 that stores various information used for various processes executed by the control unit 17 and various information obtained by various processes executed by the control unit 17. The control unit 17 controls the operation of at least one of the roll rotation drive unit 13, the doctor bar drive unit 14, and the roll push drive unit 15 based on various information stored in the storage unit 23. Hereinafter, this point will be specifically described.

As shown in the graphs of FIGS. 4 to 6, the storage unit 23 of the present embodiment has the film thickness of the ink 4 on the coating surface 3 of the substrate 2, the pushing amount of the doctor bar 12, the rotation speed of the coating roll 11, and the coating roll. Control information associated with at least one of the pushing amounts of 11 is stored. The film thickness of the ink 4 in the control information is determined after the ink 4 is applied to the coated surface 3 of the substrate 2 and then UV-cured and post-baked to make the ink 4 on the coated surface 3 a solder resist. The film thickness. Further, the film thickness of the ink 4 in the control information may be, for example, the film thickness after the exposure process and the development process are performed.

The graph of FIG. 4 is control information in which the pushing amount of the doctor bar 12 with respect to the coating roll 11 is associated with the film thickness of the ink 4 (solder resist) on the coated surface 3 of the substrate 2, and the pushing of the doctor bar 12 is shown. Used to control the amount. In the control information of FIG. 4, the rotation speed of the coating roll 11 and the pushing amount of the coating roll 11 are constant.
In the graph of FIG. 4, the film thickness of the ink 4 on the coating surface 3 of the substrate 2 decreases as the pushing amount of the doctor bar 12 with respect to the coating roll 11 increases. This is because the larger the pushing amount of the doctor bar 12, the smaller the film thickness of the ink 4 remaining on the peripheral surface 111 of the coating roll 11 after being scraped off by the doctor bar 12.

The graph of FIG. 5 is control information in which the rotation speed of the coating roll 11 is associated with the film thickness of the ink 4 (solder resist) on the coating surface 3 of the substrate 2, and the rotation speed of the coating roll 11 is controlled. Used for. In the control information of FIG. 5, the pushing amount of the doctor bar 12 and the pushing amount of the coating roll 11 are constant.
In the graph of FIG. 5, as the rotation speed of the coating roll 11 increases, the film thickness of the ink 4 on the coating surface 3 of the substrate 2 increases. This is because the higher the rotation speed of the coating roll 11, the smaller the pressure (line thickness) that the coating roll 11 receives from the doctor bar 12 per unit time, so that the coating roll 11 is scraped off by the doctor bar 12 and then the coating roll 11. This is due to the increase in the film thickness of the ink 4 remaining on the peripheral surface 111.

The graph of FIG. 6 is control information in which the pressing amount of the coating roll 11 with respect to the coating surface 3 of the substrate 2 and the film thickness of the ink 4 (solder resist) on the coating surface 3 of the substrate 2 are associated with each other. It is used to control the rotation speed of 11. In the control information of FIG. 6, the pushing amount of the doctor bar 12 and the rotation speed of the coating roll 11 are constant.
In the graph of FIG. 6, as the amount of pressing of the coating roll 11 against the coating surface 3 of the substrate 2 increases, the film thickness of the ink 4 on the coating surface 3 of the substrate 2 decreases. This is because the larger the pushing amount of the coating roll 11, the smaller the gap between the coating surface 3 of the substrate 2 through which the ink 4 on the coating roll 11 can pass and the peripheral surface 111 of the coating roll 11.

The three control information of FIGS. 4 to 6 described above may be individually stored in the storage unit 23. For example, control information obtained by selecting and combining two of the three of FIGS. 4 to 6 is stored in the storage unit 23. It may be stored, or control information that combines all three of FIGS. 4 to 6 may be stored.

The control unit 17 controls the operation of at least one of the roll rotation drive unit 13, the doctor bar drive unit 14, and the roll push drive unit 15 based on the above-mentioned control information. This makes it possible to apply the ink 4 to the coating surface 3 with a desired film thickness. For example, an operator who handles the coating device 1 inputs a target value (target film thickness) of the film thickness of the ink 4 to an input unit (not shown) such as a keyboard, and the control unit 17 inputs the target film based on the control information. By setting at least one of the pushing amount of the doctor bar 12 corresponding to the thickness, the rotation speed of the coating roll 11, and the pushing amount of the coating roll 11, the ink 4 is applied to the substrate 2 with a film thickness corresponding to the target film thickness. It can be applied to the surface 3.

Further, in the storage unit 23 of the present embodiment, the position of the substrate 2 in the direction (transfer direction) in which the coating roll 11 and the substrate 2 are relatively transferred by the transfer unit 16 and the ink on the coating surface 3 of the substrate 2 Target information associated with the plurality of target film thicknesses of 4 is stored.
As shown in FIG. 8, for example, the target information includes a plurality of regions R1 to R7 (see FIG. 7) arranged in the transfer direction of the substrate 2 on the coated surface 3 of the substrate 2, and a target film of the ink 4 in each region R1 to R7. It is a data table associated with the thickness. In FIG. 7, the transfer direction of the substrate 2 is the left direction, and the ink 4 is sequentially applied to the coating surface 3 of the substrate 2 from the left end of the substrate 2 to the right.

Further, as shown in FIG. 3, the coating device 1 of the present embodiment includes a substrate position detecting unit 30 that detects the position of the substrate 2 in the transfer direction.
The control unit 17 refers to the target information (see FIG. 8) stored in the storage unit 23, and refers to the target film thickness of the ink 4 corresponding to the position of the substrate 2 output from the substrate position detection unit 30, and the control described above. The operation of at least one of the roll rotation drive unit 13, the doctor bar drive unit 14, and the roll push drive unit 15 is controlled based on the information (see FIGS. 4 to 6). Thereby, the film thickness of the ink 4 on the coating surface 3 can be appropriately changed according to the position of the substrate 2 in the transfer direction.

The substrate position detection unit 30 described above may include, for example, a pressing detection sensor 31, a speed detection sensor 32, and a position calculation unit 34.
The pressing detection sensor 31 detects the pressing of the coating roll 11 against the substrate 2. The pressing detection sensor 31 may be composed of, for example, a pressure sensor provided on the coating roll, or may be composed of, for example, a unit drive unit 19 (roll pressing drive unit 15) including a pulse motor.
The speed detection sensor 32 detects the rotation speed of the coating roll 11 rolling on the coating surface 3 of the substrate 2. The speed detection sensor 32 may be composed of, for example, a sensor that directly detects the rotation speed of the coating roll 11, or may be composed of, for example, a roll rotation drive unit 13 including a pulse motor.

The position calculation unit 34 sets the coating start position at which the ink 4 is started to be applied to the coating surface 3 of the substrate 2 based on the detection information detected by the pressing detection sensor 31. Further, the position calculation unit 34 continuously calculates the position of the substrate 2 in the transfer direction based on the rotation speed of the coating roll 11 detected by the speed detection sensor 32 with reference to the coating start position. The position calculation unit 34 may be included in the control unit 17, for example.

Further, the substrate position detection unit 30 described above may include, for example, a distance detection sensor 33 that detects the relative transfer distance between the coating roll 11 and the substrate 2 by the transfer unit 16.
In this case, the position calculation unit 34 sets the coating start position at which the ink 4 has started to be applied to the coating surface 3 of the substrate 2 in the same manner as described above, and then sets the distance detection sensor with the coating start position as a reference. Based on the transfer distance detected in 33, the position of the substrate 2 in the transfer direction is continuously calculated.
The substrate position detection unit 30 may include both the speed detection sensor 32 and the distance detection sensor 33 described above, but may include, for example, only one of them.

The coating start position set by the position calculation unit 34 is, for example, that the magnitude of fluctuation in the film thickness of the ink 4 on the coating surface 3 is within an allowable range at the start of pressing the coating roll 11 against the coating surface 3 of the substrate 2. It is recommended that the position be set to.
The coating start position set by the position calculation unit 34 may be the position XP of the substrate 2 on which the coating roll 11 is pressed in the transfer direction of the substrate 2, for example, as shown in FIGS. 7 and 9. For example, when the coating film thickness (the film thickness of the ink 4 on the coating surface 3) immediately after the coating roll 11 is pressed against the substrate 2 is stable, the pressing amount of the doctor bar 12, the rotation speed of the coating roll 11, and so on. When the coating film thickness immediately after the coating roll 11 is pressed against the substrate 2 is stabilized by controlling at least one of the pressing amounts of the coating roll 11, the coating start position may be set to the position XP of the substrate 2.

Further, for example, when the coating film thickness is not stable until the coating roll 11 advances by a predetermined distance D2 in the transfer direction of the substrate 2 from the position XP of the substrate 2 pressed against the substrate 2, the coating start set by the position calculation unit 34 The position may be, for example, the position X0 of the substrate 2 which is advanced by a predetermined distance D2 from the position XP of the substrate 2.
The predetermined distance D2 may be obtained, for example, by conducting a test with the coating device 1 and measuring the distance from the position XP on which the coating roll 11 is pressed until the coating film thickness stabilizes. Further, the predetermined distance D2 is, for example, as shown in FIG. 9, from the first position P1 of the peripheral surface 111 of the coating roll 11 to which the doctor bar 12 is pressed in the rotation direction of the coating roll 11 to the coating surface 3 of the substrate 2. The distance D1 (= 2πr × θ / 360 °) or more on the peripheral surface 111 reaching the second position P2 of the peripheral surface 111 of the coating roll 11 to be pressed may be set.
Further, the predetermined distance D2 controls, for example, at least one of the pushing amount of the doctor bar 12, the rotation speed of the coating roll 11, and the pushing amount of the coating roll 11 when the coating roll 11 is pressed against the substrate 2, and the coating film thickness is controlled. May be set shorter than the distance D1 by stabilizing the distance.

Next, the method of applying the ink 4 according to the present embodiment will be described.

In the method of applying the ink 4 of the present embodiment, the ink 4 applied to the peripheral surface 111 of the rotating coating roll 11 is scraped off by the doctor bar 12 pressed against the peripheral surface 111 of the coating roll 11, thereby causing the ink 4 to be applied. Is applied to the peripheral surface 111 of the coating roll 11 with a predetermined thickness. Further, the ink 4 is applied to the coating surface 3 of the substrate 2 by pushing the rotating coating roll 11 into the coating surface 3 of the substrate 2.
Then, in the method of applying the ink 4 of the present embodiment, at least one of the pushing amount of the doctor bar 12 with respect to the peripheral surface 111 of the coating roll 11, the rotation speed of the coating roll 11, and the pushing amount of the coating roll 11 is changed.
Hereinafter, the method of applying the ink 4 using the application device 1 of the present embodiment will be described more specifically.

First, a procedure for applying the ink 4 to the coating surface 3 of the substrate 2 will be described.
When applying the ink 4 to the coating surface 3 of the substrate 2, first, as shown in FIG. 11, a preparatory step of positioning the first end portion of the substrate 2 in the transfer direction between the pair of coating rolls 11 and 11. To carry out. In the preparatory step, as shown in FIG. 10, in a state where the substrate 2 is held by the holding portion 21 of the substrate transfer unit 20, the substrate 2 is lowered by the substrate transfer unit 20 and moved to the position shown in FIG. Good. In the preparatory step, for example, after the holding portion 21 holds the substrate 2 below the pair of coating rolls 11 and 11, the substrate 2 is passed between the pair of coating rolls 11 and 11. It may be raised and moved to the position shown in FIG. Further, the coating roll 11 may be rotated when the coating preparation is completed in the preparation step, but may be stopped until the pressing step described later is performed.

After completing the above-mentioned preparatory steps, as shown in FIG. 11, the pair of substrates 2 are sandwiched between the pair of coating rolls 11 and 11 from the thickness direction thereof, and the coating rolls 11 are rotated on the coating surfaces 3 while rotating the coating rolls 11. The pressing process is performed and the coating operation is started.
In the pressing step, one coating roll 11 is moved by the roll pressing drive unit 15 (unit drive unit 19) so that one coating roll 11 (the coating roll 11 on the right side in FIG. 11) approaches the other coating roll 11. Just do it. By carrying out the pressing step, the pair of coating rolls 11 and 11 are pushed into the respective coating surfaces 3 of the substrate 2.
When the rotation of the coating roll 11 is stopped in the preparation step described above, in the pressing step, each coating roll 11 is rotated (idle) by an angle θ (see FIG. 9) or more corresponding to the distance D1 on the peripheral surface 111. After that, each coating roll 11 may be pressed against each coating surface 3 of the substrate 2. As a result, the application of the ink 4 to the coating surface 3 can be started from the time when the coating roll 11 is pressed against the coating surface 3 of the substrate 2.

After that, as shown in FIG. 12, a transfer step of transferring the substrate 2 in the transfer direction by the substrate transfer unit 20 is performed. In the transfer step, the transfer speed of the substrate 2 by the substrate transfer unit 20 is made to correspond to the rotation speed of the coating roll 11 so that each coating roll 11 rolls on each coating surface 3 of the substrate 2. By carrying out the transfer step, the ink 4 is applied to each coated surface 3 of the substrate 2 from the first end portion to the second end portion of the substrate 2 in the transfer direction.
Then, as shown in FIG. 13, when the second end portion of the substrate 2 reaches between the pair of coating rolls 11 and 11, the coating of the ink 4 on the coating surface 3 of the substrate 2 is completed.
In the above-mentioned coating of the ink 4, the rotation of the coating roll 11, the movement of the holding unit 21, and the like are performed by the control unit 17 controlling the operations of the roll rotation driving unit 13, the transfer driving unit 22, and the like.

Then, in the ink 4 coating method of the present embodiment, in the transfer step described above, the control unit 17 controls the operation of at least one of the doctor bar drive unit 14, the roll rotation drive unit 13, and the roll push drive unit 15. Therefore, at least one of the pushing amount of the doctor bar 12, the rotation speed of the coating roll 11, and the pushing amount of the coating roll 11 is changed. More specifically, in the ink 4 coating method of the present embodiment, the pushing amount of the doctor bar 12, the rotation speed of the coating roll 11, and the coating are performed at a position (predetermined position) in the middle of the coating surface 3 of the substrate 2 in the transfer direction. At least one of the pushing amounts of the roll 11 is changed.
By changing at least one of the pushing amount of the doctor bar 12, the rotation speed of the coating roll 11, and the pushing amount of the coating roll 11, the coating is applied to the coating surface 3 of the substrate 2 as shown in FIGS. The film thickness of the ink 4 can be changed.

In the above-described ink 4 coating method, for example, the step of applying the ink 4 to the coating surface 3 of the substrate 2 (particularly the pressing step and the transfer step) may be performed only once, but for example, it is repeated a plurality of times. May be good.
In this case, after applying the ink 4 on the coated surface 3 of the substrate 2, UV curing and post-baking treatment may be performed, and then the ink 4 may be applied again on the coated surface 3 of the substrate 2. Further, when forming a solder resist having a predetermined opening pattern on the coated surface 3 of the substrate 2, an exposure treatment and a development treatment may be carried out before the UV cure and post-bake treatments are carried out.

According to the coating device 1 and the coating method of the ink 4 of the present embodiment, the film thickness of the ink 4 applied to the coating surface 3 of the substrate 2 is increased while the ink 4 is being applied to the coating surface 3 of the substrate 2. Can be changed. Therefore, it is possible to manufacture a plurality of types of circuit boards having different solder resist film thicknesses on the same substrate 2. can do. As a result, it is possible to reduce the working time required for manufacturing a plurality of types of circuit boards and to reduce the amount of materials used for the substrate and the solder resist.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[substrate]
In this embodiment, as the substrate 2, a double-sided substrate in which a conductor circuit made of a copper material is formed on both sides of a glass epoxy plate material (glass epoxy plate) is prepared. The dimensions of the glass epoxy plate were 612 mm in length, 512 mm in width, and 0.8 mm in thickness. The vertical dimension of the glass epoxy plate was set to the dimension corresponding to the transfer direction of the substrate 2. The horizontal dimension of the glass epoxy plate was the dimension in the direction orthogonal to the transfer direction and the thickness direction of the substrate 2. The conductor circuit was formed on both sides of the glass epoxy plate by a known method.

[Ink application method (solder resist formation method)]
In this embodiment, first, the substrate 2 was subjected to an acid cleaning treatment and a surface roughness treatment. Next, using the coating device 1 of the present embodiment, the ink 4 was applied to both surfaces of the substrate 2 (both coated surfaces 3 and 3). Then, the applied ink 4 was subjected to an exposure treatment and a development treatment to form a predetermined opening pattern. Then, UV curing and post-baking treatment were performed to use ink 4 on both sides of the substrate 2 as a solder resist.

In this example, as shown in each graph of FIGS. 14 to 20, seven kinds of ink 4 coating methods (Examples 1 to 7) were carried out.
In the first coating method (Example 1), as shown in FIG. 14, the film thickness of the ink 4 is changed by changing the pushing amount of the doctor bar 12, the rotation speed of the coating roll 11, and the pushing amount of the coating roll 11. Changed.
In the second coating method (Example 2), as shown in FIG. 15, the film thickness of the ink 4 was changed by changing the pushing amount of the doctor bar 12 and the rotation speed of the coating roll 11. In Example 2, the pushing amount of the coating roll 11 was kept constant.
In the third coating method (Example 3), as shown in FIG. 16, the film thickness of the ink 4 was changed by changing the pressing amount of the doctor bar 12 and the pressing amount of the coating roll 11. In Example 3, the rotation speed of the coating roll 11 was kept constant.
In the fourth coating method (Example 4), as shown in FIG. 17, the film thickness of the ink 4 was changed by changing the rotation speed of the coating roll 11 and the pushing amount of the coating roll 11. In Example 4, the pushing amount of the doctor bar 12 was kept constant.

In the fifth coating method (Example 5), as shown in FIG. 18, the film thickness of the ink 4 was changed by changing the pushing amount of the doctor bar 12. In Example 5, the rotation speed of the coating roll 11 and the pushing amount of the coating roll 11 were kept constant.
In the sixth coating method (Example 6), as shown in FIG. 19, the film thickness of the ink 4 was changed by changing the rotation speed of the coating roll 11. In Example 6, the pushing amount of the doctor bar 12 and the pushing amount of the coating roll 11 were kept constant.
In the seventh coating method (Example 7), as shown in FIG. 20, the film thickness of the ink 4 was changed by changing the pressing amount of the coating roll 11. In Example 7, the pushing amount of the doctor bar 12 and the rotation speed of the coating roll 11 were kept constant.

In each of the coating methods of Examples 1 to 7, the substrate is located at the position X0 of the coating surface 3 of the substrate 2 which is advanced by a predetermined distance D2 in the transfer direction of the substrate 2 from the position XP of the substrate 2 on which the coating roll 11 is pressed. The coating start position (coating start position X0) of the ink 4 in No. 2 was set (see FIG. 9).
The horizontal axis of each graph shown in FIGS. 14 to 20 indicates the coating distance from the coating start position X0, and corresponds to the X-axis direction of the substrate 2 illustrated in FIG. 7.

In each of the graphs 14 to 16 and 18, the reference (zero point) of the pushing amount of the doctor bar 12 is, for example, the position of the doctor bar 12 where the pressing pressure of the doctor bar 12 against the coating roll 11 becomes zero (for example, the doctor bar). 12 is a position where the coating roll 11 is only in contact with the coating roll 11). The positive direction of the pushing amount in each of the graphs 14 to 16 and 18 means that the pressing pressure of the doctor bar 12 against the coating roll 11 increases.

In each of the graphs of FIGS. 14, 16, 17, and 20, the reference (zero point) of the pressing amount of the coating roll 11 is, for example, the coating roll 11 in which the pressing pressure of the coating roll 11 against the coating surface 3 of the substrate 2 is zero. The position (for example, the position of the coating roll 11 in which the coating roll 11 is only in contact with the substrate 2). The positive direction of the pushing amount of the coating roll 11 in each of the graphs 14, 16, 17, and 20 means that the pressing pressure of the coating roll 11 against the coating surface 3 of the substrate 2 increases.

In Examples 1 to 7, each target film thickness T1, T2, T3 (see FIG. 8) of the ink 4 in each region R1 to R7 of the coating surface 3 of the substrate 2 shown in FIG. 7 was set as follows. ..
Target film thickness T1 = 12 μm
Target film thickness T2 = 14 μm
Target film thickness T3 = 16 μm
The target film thicknesses T1, T2, and T3 of the ink 4 in each region R1 to R7 are the same on both the coated surfaces 3 and 3 of the substrate 2.

In Examples 1 to 7, as shown in the substrate 2 of FIG. 7 and the graphs of FIGS. 14 to 20, when the ink 4 was applied to the coating surface 3, the film thickness of the ink 4 was changed by the following procedure. ..
First, at the position X1 of the substrate 2 which is the boundary between the region R1 and the region R2 of the coating surface 3, the pushing amount of the doctor bar 12 is reduced, the rotation speed of the coating roll 11 is increased, and the coating roll 11 is pushed. By reducing the amount, the film thickness of the ink 4 applied to the coating surface 3 of the substrate 2 was increased.
Next, at the position X2 of the substrate 2 which is the boundary between the region R2 and the region R3 of the coating surface 3, the pushing amount of the doctor bar 12 is further reduced, the rotation speed of the coating roll 11 is further increased, or the coating roll is further increased. By further reducing the pushing amount of 11, the film thickness of the ink 4 applied to the coating surface 3 of the substrate 2 was further increased.

After that, at the position X3 of the substrate 2 which is the boundary between the region R3 and the region R4 of the coating surface 3, the pushing amount of the doctor bar 12 is increased, the rotation speed of the coating roll 11 is decreased, and the pushing of the coating roll 11 is performed. By increasing the amount, the film thickness of the ink 4 applied to the coating surface 3 of the substrate 2 was reduced.
Then, at the position X4 of the substrate 2 which is the boundary between the region R4 and the region R5 of the coating surface 3, the pushing amount of the doctor bar 12, the rotation speed of the coating roll 11, and the coating roll are the same as in the case of the position X1 of the substrate 2. The pushing amount of 11 was set, and the film thickness of the ink 4 applied to the region R5 was set to be the same as that of the region R2.

Further, at the position X5 of the substrate 2 which is the boundary between the region R5 and the region R6 of the coating surface 3, the pushing amount of the doctor bar 12, the rotation speed of the coating roll 11, and the coating roll are the same as in the case of the position X2 of the substrate 2. The pushing amount of 11 was set, and the film thickness of the ink 4 applied to the region R6 was set to be the same as that of the region R3.
Further, at the position X6 of the substrate 2 which is the boundary between the region R6 and the region R7 of the coating surface 3, the pushing amount of the doctor bar 12, the rotation speed of the coating roll 11, and the coating roll are the same as in the case of the position X3 of the substrate 2. By setting the pushing amount of 11, the film thickness of the ink 4 applied to the region R7 was made equivalent to that in the case of the region R4.
Finally, the application of the ink 4 to the coated surface 3 was completed at the position X7 of the substrate 2 forming the end of the region R7 of the coated surface 3.

In Examples 1 to 7, the portion of the substrate 2 corresponding to the regions R2 and R5 of the coating surface 3 set to the target film thickness T2 was defined as the portion manufactured as the first circuit board 201. The first circuit board 201 is a portion surrounded by a broken line in FIG. 7, and a plurality of first circuit boards 201 are provided in each of the regions R2 and R5.
Further, the portion of the substrate 2 corresponding to the regions R3 and R6 of the coating surface 3 set to the target film thickness T3 was defined as the portion manufactured as the second circuit board 202. The second circuit board 202 is a portion surrounded by a broken line in FIG. 7, and a plurality of the second circuit boards 202 are provided in each of the regions R3 and R6.
The portion of the substrate 2 corresponding to the regions R1, R4, and R7 of the coating surface 3 set to the target film thickness T1 is a portion that is not manufactured as a circuit board. Since the target film thickness T1 in the regions R1, R4 and R7 can be set thinner than the target film thickness T2 and T3 in the regions R2, R3, R5 and R6 and applied, the ink can be applied with a uniform thickness as in the conventional case. Compared with the case where 4 is applied, the amount of ink 4 applied to the substrate 2 including the circuit boards 201 and 202 can be reduced.

[Measurement of ink (solder resist) film thickness]
The film thickness of the ink 4 applied by each of the coating methods of Examples 1 to 7 described above was measured. The film thickness of the ink 4 to be measured is not the film thickness immediately after the ink 4 is applied to both the coated surfaces 3 and 3 of the substrate 2, but the ink 4 is applied to both the coated surfaces 3 and 3 of the substrate 2. After that, UV curing and post-baking treatment were performed to obtain a film thickness after the ink 4 on each coated surface 3 was made into a solder resist. Further, the film thickness of the ink 4 may be, for example, the film thickness after the exposure treatment and the development treatment are performed.
The film thickness of the ink 4 (solder resist) was measured using a laser microscope in a predetermined aperture pattern formed on the ink 4 (solder resist).
In each graph of FIGS. 14 to 20, the relationship between the position of the substrate 2 in the transfer direction (coating distance based on the coating start position X0) and the film thickness of the ink 4 measured by the above measuring method is described. .. Since there is no difference in the tendency of the change in the film thickness of the ink 4 with respect to the position of the substrate 2 on both the coated surfaces 3 and 3 of the substrate 2, the graphs of FIGS. 14 to 20 show that the one coated surface 3 of the substrate 2 is used. Only the relationship between the position of the substrate 2 and the film thickness of the ink 4 is described.

[Evaluation of Examples 1 to 7]
FIG. 21 shows the results of examining the error between the target film thickness of the ink 4 and the measured film thickness with respect to the film thickness of the ink 4 applied by each of the coating methods of Examples 1 to 7. In FIG. 21, in the “one coated surface” column, there is an error between the target film thickness of the ink 4 and the measured film thickness on the coated surface 3 of the substrate 2 on which the one coated roll 11 driven by the unit drive unit 19 is pressed. Was described. In the column of "the other coated surface", an error between the target film thickness of the ink 4 and the measured film thickness on the coated surface 3 of the substrate 2 on which the other coating roll 11 not driven by the unit driving unit 19 is pressed is described. The error of the measured film thickness with respect to the target film thickness of the ink 4 is indicated by "+" when the measured film thickness is larger than the target film thickness, and is indicated by "-" when the measured film thickness is smaller than the target film thickness. It was.
As shown in FIG. 21, in each of Examples 1 to 7, the error of the measured film thickness with respect to the target film thickness of the ink 4 was 1.9 μm at the maximum. That is, in Examples 1 to 7, it was confirmed that the ink 4 can be applied with a film thickness close to the target film thickness. As a result, it was confirmed that two types of circuit boards 201 and 202 having different film thicknesses of the solder resist (ink 4) can be manufactured using the same substrate 2.

Further, in Examples 4, 6 and 7 in which the pushing amount of the doctor bar 12 was constant, the maximum value of the error of the film thickness of the ink 4 with respect to the target film thickness of the ink 4 was 1.4 μm or more. On the other hand, in Examples 1 to 3 and 5 in which the pushing amount of the doctor bar 12 was changed, the maximum value of the error of the film thickness of the ink 4 with respect to the target film thickness of the ink 4 was 1.3 μm or less. It was. Therefore, when the ink 4 is applied to the coating surface 3 of the substrate 2 by the coating device 1 and the coating method of the ink 4 of the present embodiment, the ink 4 is coated with a high film thickness by changing the pushing amount of the doctor bar 12. It was confirmed that the coating could be applied to the substrate 2 with high accuracy.

Further, looking at the graphs of FIGS. 14 to 20, in Examples 1 to 3 and 5 in which the pushing amount of the doctor bar 12 was changed, compared with Examples 4, 6 and 7 in which the pushing amount of the doctor bar 12 was constant. It was confirmed that the film thickness of the ink 4 changed significantly. That is, it was confirmed that changing the pushing amount of the doctor bar 12 greatly contributes to the change in the film thickness of the ink 4 rather than changing the rotation speed of the coating roll 11 and the pushing amount of the coating roll 11. .. Therefore, it was confirmed that by changing the pushing amount of the doctor bar 12, it is possible to manufacture a plurality of types of circuit boards having significantly different film thicknesses of the ink 4 (solder resist) using the same substrate 2.

Although the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

The coating apparatus of the present invention is not limited to being configured to apply ink to both coated surfaces of the substrate, and may be configured to be applied to, for example, only one coated surface of the substrate. That is, the coating apparatus of the present invention may include at least one coating roll. Further, in the ink application method of the present invention, at least the ink may be applied to one of the coated surfaces of the substrate in the same manner.

Further, for example, a program for realizing the functions of the control unit and the position calculation unit of the coating device is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read and executed by the computer system. As a result, the processing executed by the control unit or the position calculation unit may be performed. The "computer system" referred to here may include hardware such as an OS and peripheral devices.

In addition, the "computer system" shall also include a homepage providing environment (or display environment) if a computer network system is used. The "computer-readable recording medium" includes a flexible disk, a magneto-optical disk, a writable non-volatile memory such as a flash memory, a portable medium such as a ROM and a CD-ROM, a hard disk built in a computer system, and the like. It refers to the storage device of.

Furthermore, the "computer-readable recording medium" is a volatile memory inside a computer system that serves as a server or client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line (for example, DRAM (Dynamic)). It also includes those that hold the program for a certain period of time, such as Random Access Memory)).
Further, the program may be transmitted from a computer system in which this program is stored in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the "transmission medium" for transmitting a program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
Further, the above program may be for realizing a part of the above-mentioned functions.
Further, a so-called difference file (difference program) may be used, which can realize the above-mentioned functions in combination with a program already recorded in the computer system.

1 Coating device 2 Substrate 3 Coating surface 4 Ink 10 Coating unit 11 Coating roll 12 Doctor bar 13 Roll rotation drive unit 14 Doctor bar drive unit 15 Roll push-in drive unit 16 Transfer unit 17 Control unit 18 Support 19 Unit drive unit 20 Board transfer Unit 21 Holding unit 22 Transfer drive unit 23 Storage unit 30 Board position detection unit 31 Pushing detection sensor 32 Speed detection sensor 33 Distance detection sensor 34 Position calculation unit

Claims (5)

A coating device that applies ink made of photosensitive resin to the coated surface of a substrate.
Have a circumferential surface facing the coating surface, a coating roll is elastically deformable elastic body,
A doctor bar pressed against the peripheral surface of the coating roll and
A roll rotation drive unit that rotationally drives the coating roll,
A doctor bar driving unit that drives the doctor bar to change the pushing amount of the doctor bar with respect to the peripheral surface of the coating roll.
A roll pushing drive unit that drives the coating roll to change the pushing amount of the coating roll with respect to the coated surface.
By controlling the operation of at least the roll pushing drive unit of the roll rotation driving unit, the doctor bar driving unit, and the roll pushing driving unit , the amount of pushing the doctor bar with respect to the peripheral surface of the coating roll and the amount of the doctor bar pushed into the coating roll rotational speed, by changing at least push-in amount of the coating roll of the push-in amount of the coating roll with respect to the coated surface, and a control unit for changing the thickness of the ink on the coating surface,
A coating device comprising. Control information in which the film thickness of the ink on the coating surface, the pushing amount of the doctor bar, the rotation speed of the coating roll, and at least the pushing amount of the coating roll among the pushing amount of the coating roll are associated with each other. Equipped with a memorized storage unit
The control unit controls the operation of at least the roll pushing drive unit among the roll rotation driving unit, the doctor bar driving unit, and the roll pushing drive unit based on the control information stored in the storage unit. The coating apparatus according to claim 1. A transfer unit that relatively transfers the coating roll and the substrate along the coating surface so that the coating roll rolls on the coating surface.
A substrate position detection unit that detects the position of the substrate with respect to the coating roll in the transfer direction by the transfer unit.
With
In the storage unit, target information in which the position of the substrate in the transfer direction and a plurality of target values of the ink film thickness on the coated surface are associated with each other is stored.
The control unit has the roll rotation drive unit, the doctor bar drive unit, and the roll push-in unit based on the target value corresponding to the position of the substrate detected by the substrate position detection unit and the control information. The coating device according to claim 2, wherein at least the operation of the roll pushing drive unit is controlled among the drive units. The board position detection unit
A pressing detection sensor that detects the pressing of the coating roll against the substrate, and
A speed detection sensor that detects the rotational speed of the coating roll that rolls on the coating surface, and
Based on the detection information detected by the pressing detection sensor, the coating start position at which ink coating is started is set on the coating surface, and the speed detection sensor detects the ink coating start position as a reference. The coating device according to claim 3, further comprising a position calculation unit that continuously calculates the position of the substrate in the transfer direction based on the rotation speed of the coating roll. By scraping the ink applied to the peripheral surface of the rotating coating roll, which is made of a photosensitive resin, with a doctor bar pressed against the peripheral surface of the coating roll, the ink is spread around the coating roll with a predetermined thickness. An ink coating method for applying the ink to the coating surface by pressing the coating roll, which is coated on the surface and rotates, into the coating surface of the substrate.
The coating roll is an elastic body that can be elastically deformed.
By changing at least the pushing amount of the coating roll among the pushing amount of the doctor bar with respect to the peripheral surface of the coating roll, the rotation speed of the coating roll, and the pushing amount of the coating roll with respect to the coating surface, the coating surface thereof. A method of applying an ink that changes the film thickness of the ink.

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