CN113453442A

CN113453442A - Pattern forming apparatus, pattern forming method, and ejection data generating method

Info

Publication number: CN113453442A
Application number: CN202110293333.8A
Authority: CN
Inventors: 中川雅晴; 胁田典宏
Original assignee: Screen Holdings Co Ltd
Current assignee: Screen Holdings Co Ltd
Priority date: 2020-03-24
Filing date: 2021-03-18
Publication date: 2021-09-28
Also published as: KR102476630B1; JP2021153085A; KR20210119302A; TW202139802A; TWI760131B

Abstract

The invention provides a pattern forming device, a pattern forming method and a jetting data generating method for forming a solder mask with a proper thickness on a wiring substrate. The pattern forming apparatus includes: a holding unit for holding the wiring substrate; a head portion for ejecting an ink droplet of a solder resist onto a surface of a wiring board by an ink jet method; a moving mechanism that relatively moves the head portion with respect to the holding portion in a direction parallel to a surface of the wiring substrate; the ejection data generating section generates ejection data indicating an ejection amount of the ink per unit area based on the solder resist pattern data indicating the pattern of the solder resist. The pattern forming apparatus further includes a control unit that forms a pattern of the solder resist on the wiring substrate by controlling the head unit and the moving mechanism based on the ejection data. The ejection data generating section generates the ejection data in which different ejection amounts are set for each of different types of patterns included in the solder resist pattern data.

Description

Pattern forming apparatus, pattern forming method, and ejection data generating method

Technical Field

The present invention relates to a technique for forming a solder resist pattern on a wiring substrate.

Background

In order to protect the conductive pattern provided on the wiring substrate, a solder resist film may be formed on the wiring substrate. The solder resist film has a function of preventing solder from adhering to a region such as a conductor wiring at the time of solder application in a subsequent step, and is also called a "solder resist". As a method for forming a solder resist, a method of ejecting droplets of an ink of a solder resist onto a wiring board by an ink jet method is known. Such techniques are disclosed in patent documents 1 and 2, for example.

Patent document 1: japanese laid-open patent publication No. 9-283893

Patent document 2: japanese laid-open patent publication No. 2008-4820

However, the pattern of the solder resist formed on the wiring substrate varies depending on the purpose and the location. When a certain amount of ink is applied to a unit area of the wiring substrate, the thickness (film thickness) of the solder resist may not be formed to a target film thickness depending on the type of pattern. For example, in the case of a fine line pattern, the height tends to be lower as the line width becomes smaller. In addition, in the intersecting pattern where lines intersect, the thickness of the solder resist tends to increase due to the rising of the solder resist. Therefore, a technique for forming a solder resist film having an appropriate film thickness is required.

Disclosure of Invention

The present invention aims to provide a technique for forming a solder resist film having an appropriate thickness on a wiring substrate.

In order to solve the above problem, a first aspect is a pattern forming apparatus for forming a pattern of a solder resist on a wiring substrate. The pattern forming apparatus includes: a holding unit for holding the wiring substrate; a head unit configured to eject an ink droplet of a solder resist onto a surface of the wiring board by an ink jet method; a moving mechanism that relatively moves the head portion with respect to the holding portion in a direction parallel to a surface of the wiring substrate; an ejection data generating section that generates ejection data indicating an ejection amount of ink per unit area based on solder resist pattern data indicating a pattern of a solder resist; and a control unit that forms a solder resist pattern on the wiring substrate by controlling the head unit and the moving mechanism based on the ejection data. The ejection data generating section generates the ejection data in which different ejection amounts are set for each of different types of patterns included in the solder resist pattern data.

A second aspect is the patterning device of the first aspect. The pattern of the solder resist film includes: a first pattern having a line shape with a first line width; and a linear second pattern having a second line width smaller than the first line width. The ejection data generation unit generates ejection data in which the ejection rate for the second pattern is set to a value larger than the ejection rate for the first pattern.

A third aspect is the patterning device of the first or second aspect. The pattern of the solder resist film includes a cross-like third pattern. The discharge data generation unit generates discharge data in which the discharge amount with respect to the third pattern is set to a value smaller than a predetermined reference discharge amount.

A fourth aspect is the patterning device of the second aspect. The pattern of the solder resist film includes a cross-like third pattern. The discharge data generation unit generates discharge data in which the discharge rate for the third pattern is set to a value smaller than the discharge rates for the first pattern and the second pattern.

A fifth aspect is the pattern forming apparatus according to any one of the first to fourth aspects. The pattern forming apparatus further includes a storage unit that stores correction table information that specifies discharge amounts per unit area for a plurality of types of patterns. The ejection data generation unit includes: a pattern determination section that determines a pattern registered in the fix-up table information in the solder resist pattern data; and a discharge rate setting unit that sets a discharge rate for the pattern specified by the pattern specifying unit, based on the correction table information.

The sixth aspect is a pattern forming method for forming a solder resist pattern on a wiring substrate. The pattern forming method includes: a step (a) of ejecting an ink droplet of a solder resist from a head onto a surface of the wiring substrate by an ink jet method; a step (b) of relatively moving the head portion with respect to the wiring substrate in a direction parallel to a surface of the wiring substrate in the step (a); and a step (c) of varying the ink ejection rate per unit area in accordance with the type of the pattern of the solder resist formed on the wiring substrate.

The seventh aspect is an ejection data generating method for generating ejection data used when ejecting droplets of solder resist ink from a head to a wiring substrate by an ink jet method. The ejection data generation method includes: a step (A) for preparing solder resist pattern data formed on a wiring substrate; and a step (B) of generating ejection data in which different ejection amounts per unit area are set for each of different types of patterns included in the solder resist pattern data.

According to the pattern forming apparatuses of the first to fifth aspects, the amount of ink discharged per unit area is increased or decreased according to the type of pattern. This enables the solder resist to be formed on the wiring substrate with an appropriate thickness for each pattern type.

According to the pattern forming apparatus of the second aspect, the solder resist having an appropriate thickness can be formed on the wiring substrate with respect to the second pattern by making the ejection rate per unit area relative to the linear second pattern having a small line width relatively large.

According to the pattern forming apparatus of the third aspect, the ejection rate per unit area of the intersecting third pattern, which tends to increase in film thickness, is made smaller than the reference ejection rate, whereby a solder resist having an appropriate thickness can be formed on the wiring substrate with respect to the intersecting pattern.

According to the pattern forming apparatus of the fourth aspect, the discharge amount per unit area of the intersecting third pattern, which tends to increase in film thickness, is made smaller than the linear first pattern and the linear second pattern, whereby the solder resist having the intersecting pattern with an appropriate film thickness can be formed on the wiring substrate.

According to the pattern forming apparatus of the fifth aspect, the discharge amount per unit area for each of the plurality of types of patterns is defined by the correction table information, so that the discharge amount of each pattern included in the solder resist pattern data can be appropriately set.

Drawings

Fig. 1 is a perspective view showing a pattern forming apparatus according to an embodiment.

Fig. 2 is a diagram showing a configuration of a computer included in the control unit.

Fig. 3 is a diagram showing a functional configuration implemented by a computer.

Fig. 4 is a diagram illustrating a flow of the operation of the pattern forming apparatus 1.

Fig. 5 is a plan view schematically showing a part of a wiring substrate on which a solder resist film having a plurality of types of patterns is formed.

Fig. 6 is a cross-sectional view schematically showing a part of a wiring substrate on which a solder resist film having a plurality of types of patterns is formed.

Fig. 7 is a diagram showing an example of correction table information.

Fig. 8 is a cross-sectional view schematically showing a wiring substrate on which solder resists of plural kinds of patterns are formed.

Description of the reference numerals:

1: pattern forming apparatus

11: device body

12: control unit

2: moving mechanism

21: object stage

2 a: y-direction moving mechanism

2 b: x-direction moving mechanism

3: head part

61: discharge data generating section

611: pattern determination unit

612: discharge rate setting unit

62: storage unit

71: solder resist pattern data

711: determining information

73: correction table information

75: ejection data

9: wiring board

911. 912, 913, 92, 93, 94: solder mask

9 a: surface of

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The structural members described in the present embodiment are merely exemplary, and are not intended to limit the scope of the present invention. In the drawings, the size and number of each part may be exaggerated or simplified as necessary for easy understanding.

In fig. 1, for convenience of explanation, arrows indicating X, Y and the Z axis which are orthogonal to each other are marked. Wherein the Z axis is parallel to the vertical direction, and the X axis and the Y axis are parallel to the horizontal direction. In the following description, the direction in which the tip of each arrow faces is defined as the plus (positive) direction, and the opposite direction is defined as the minus (negative) direction.

<1 > embodiment >

Fig. 1 is a perspective view showing a pattern forming apparatus 1 according to an embodiment. The pattern forming apparatus 1 forms a pattern of a solder resist on a surface 9a of a printed wiring board (hereinafter, simply referred to as "wiring board") 9 with an ink of the solder resist. The pattern forming apparatus 1 forms a pattern by an ink jet method. The wiring board 9 is a plate-like member made of, for example, an epoxy glass resin. However, the wiring board 9 may have other shapes such as a sheet member having flexibility. The solder resist protects the conductive pattern on the wiring substrate 9. The conductive pattern includes a wiring, a pad, and other patterns. The solder resist may not be formed in a region where the solder paste is applied in a subsequent process and other regions where the solder resist should not be provided.

The pattern forming apparatus 1 includes an apparatus main body 11 and a control unit 12. The device body 11 includes a moving mechanism 2, a head 3, and a tank 4. The moving mechanism 2 includes a Y-direction moving mechanism 2a and an X-direction moving mechanism 2 b. The Y-direction moving mechanism 2a moves the wiring substrate 9 in the Y direction parallel to the surface 9a of the wiring substrate 9. The X-direction moving mechanism 2b moves the head 3 in the X direction perpendicular to the Y direction and parallel to the surface 9a of the wiring substrate 9. Various mechanisms can be used as the Y-direction moving mechanism 2a and the X-direction moving mechanism 2 b. For example, a ball screw mechanism having a motor mounted thereon may be used, or a linear motor may be used.

The head 3 ejects a fine droplet of solder resist ink (hereinafter simply referred to as "ink") to the moving wiring board 9. The tank 4 stores ink supplied to the head 3. The control unit 12 controls the moving mechanism 2 and the head 3. Ink is supplied from the tank 4 to the head 3 via the tube 41.

The Y-direction moving mechanism 2a includes a stage 21 for holding the wiring substrate 9. The stage 21 is an example of a holding portion. The wiring substrate 9 is held on the upper surface of the stage 21. A plurality of holes are formed in the surface of the stage 21, and the holes are connected to a suction device not shown. By sucking air through the hole, the wiring board 9 is attracted to the upper surface of the stage 21. Further, the surface of the stage 21 may have a groove extending in the horizontal direction from the hole, and the area of the adsorption wiring substrate 9 is enlarged by the groove. The surface of the stage 21 is formed as a porous member, and the wiring substrate 9 can be sucked through the porous member. The stage 21 may have a mechanical structure for holding the wiring substrate 9.

In the patterning device 1, if the head 3 is a member that moves relative to the stage 21, the moving mechanism 2 can have various configurations. For example, the stage 21 may be fixed and the head 3 may be moved in the X direction and the Y direction. The head 3 may be moved in the Y direction and the stage 21 may be moved in the X direction.

The head 3 is provided with a discharge unit having a plurality of discharge ports arranged at equal intervals in the X direction. Droplets of ink are ejected from the respective ejection openings by an ink jet method. The ink is ejected in the (-Z) direction toward the surface 9a of the wiring substrate 9. As the ink jet system, various structures can be used, and a structure using a piezoelectric and a structure using a heater can be used.

The stage 21 is moved in the Y direction parallel to the wiring substrate 9 by the Y direction moving mechanism 2a while discharging droplets of ink from the plurality of discharge ports, and the ink is supplied to a region extending in the Y direction. Hereinafter, the movement of the wiring substrate 9 in the Y direction is referred to as "main scanning". In fact, in one main scan of the wiring substrate 9, a plurality of lines of ink corresponding to a plurality of ejection ports are formed on the wiring substrate 9. When one main scanning is completed, the head 3 is slightly moved in the X direction parallel to the wiring substrate 9 by the X direction moving mechanism 2b, and the wiring substrate 9 is moved in the (-Y) direction by the Y direction moving mechanism 2 a. Thereby, the second main scanning is performed to form lines of ink adjacent to the lines of ink formed in the previous main scanning.

By repeating the main scanning a predetermined number of times, the solder resist is formed in a region having a width substantially equal to the arrangement width of the plurality of heads in the X direction. Since the solder resist is formed only in a desired area, the pattern of the solder resist can be formed accurately. Hereinafter, a width substantially equal to the arrangement width of the plurality of heads in the X direction is referred to as a "unit width", and a region where the solder resist is formed with the width is referred to as a "unit region". When forming a solder resist in one unit area, the head 3 is moved by a unit width in the X direction by the X-direction moving mechanism 2b, and the above-described main scanning is repeated, thereby forming a solder resist in a unit area adjacent to the previous unit area. By repeating the formation of the solder resist in the unit area and the movement of the head portion 3 in the X direction, a solder resist pattern is formed in all necessary areas on the wiring substrate 9. Further, the main scanning may be performed a plurality of times for the same unit area. This can increase the amount of ink to be applied to the unit area.

Fig. 2 is a diagram showing a configuration of the computer 5 included in the control unit 12. The computer 5 includes a CPU51 that executes various arithmetic processes, a ROM52 that stores basic programs, and a RAM53 that stores various information. In addition, the computer 5 includes: a fixed disk 54 for storing information, a display 55 for displaying various information such as images, an input unit 56 for receiving an input from an operator, a reading device 57 for reading information from the computer-readable storage medium 8, and a communication unit 58 for transmitting and receiving signals to and from the apparatus main body 11. The input unit 56 includes a keyboard 56a and a mouse 56 b. The storage medium 8 is, for example, an optical disk, a magnetic disk, an opto-magnetic disk, or a memory card.

In the computer 5, the program 80 is read from the storage medium 8 by the reading device 57 in advance and stored in the fixed disk 54. The program 80 may also be stored on the fixed disk 54 via a network. The CPU51 uses the RAM53 or the fixed disk 54 according to the program 80 and performs arithmetic processing. The CPU51 functions as an arithmetic unit in the computer 5. The computer 5 may include another processor (GPU and the like) functioning as an arithmetic unit other than the CPU 51.

Fig. 3 is a diagram showing a functional configuration realized by the computer 5. The computer 5 functions as an ejection data generating unit 61 and a storage unit 62. The storage unit 62 corresponds to the RAM53 and the fixed disk 54. The discharge data generation unit 61 includes a pattern determination unit 611 and a discharge amount setting unit 612. The ejection data generating unit 61 may be implemented by a plurality of computers. All or a part of the functions of the ejection data generating section 61 may be realized by hardware by a dedicated circuit.

The storage section 62 stores the solder resist pattern data 71, the correction table information 73, and the ejection data 75. The solder resist pattern data 71 and the correction table information 73 may be supplied to the computer 5 via the reader 57 or the communication unit 58, for example, or may be generated using the computer 5. The functions of the pattern determination unit 611 and the ejection amount setting unit 612 will be described in detail in the description of the operation of the pattern forming apparatus 1.

Fig. 4 is a diagram illustrating a flow of the operation of the pattern forming apparatus 1. Steps S12 to S14 in fig. 4 are arithmetic processing executed by the controller 12, and step S15 is an operation of the apparatus main body 11 under the control of the controller 12.

First, solder resist pattern data 71 and correction table information 73 are prepared and stored in the storage unit 62 (step S11). The solder resist pattern data 71 is information indicating a pattern of a predetermined solder resist film formed on the surface 9a of the wiring substrate 9. The solder resist pattern data 71 may be vector data at the stage where the solder resist pattern data 71 is stored in the storage section 62, but can be converted into raster data as appropriate. The correction table information 73 is information for setting the amount of ink ejected per unit area (hereinafter, simply referred to as "ejection amount") from the head 3 according to the type of a predetermined pattern. In the present embodiment, the "pattern" does not refer to the entire solder resist formed on the wiring substrate 9, but refers to the shape of a part of the solder resist in the entire solder resist.

Fig. 5 is a plan view schematically showing a part of the wiring substrate 9 on which the solder resists 911, 913, 93 of plural kinds of patterns are formed. Fig. 6 is a cross-sectional view schematically showing a part of the wiring substrate 9 on which the solder resists 911, 913, 93 of plural kinds of patterns are formed. The solder resists 911 and 913 are linear patterns, and the solder resist 93 is a pattern having a whole surface area of a predetermined area or more.

A plurality of (here, four) conductive patterns 81 are provided on the surface 9a of the wiring substrate 9 at intervals. Specifically, the conductive pattern 81 is a circuit pattern formed by etching a copper film having a predetermined thickness. The upper side of each conductive pattern 81 is covered with solder 85. The solder resist 911 as a line pattern is disposed between the adjacent

conductive patterns

81, 81. As shown in fig. 6, each solder resist 911 functions as a dam for insulating the

solders

85 and 85 covering the adjacent

conductive patterns

81 and 81 from each other so as not to contact each other.

The solder resist 913 is also a line pattern as in the solder resist 911. However, the solder resist 913 has a line width L2 larger than the line width L1 of the solder resist 911.

A conductive pattern 83 is formed on the surface 9a of the wiring substrate 9. The solder resist 93 has a circular opening 931 which covers a portion other than the top end portion of the conductive pattern 83 and exposes the top end portion of the conductive pattern 83 to the outside.

In this way, the patterning device 1 forms patterns of various shapes and sizes on the wiring substrate 9 based on the solder resist pattern data 71, in addition to the solder resists 911, 913, and 93 shown in fig. 5 and 6.

Returning to fig. 4, pattern determination section 611 determines the registration pattern contained in solder resist pattern data 71 (fig. 4: step S12). As described later, the registered pattern is a pattern defined in the correction table information 73 (see fig. 7). The pattern determination section 611 searches the solder resist pattern data 71 for a portion that matches each of the registration patterns, and when a registration pattern is found, supplies determination information 711 indicating the size and position of the area occupied by the registration pattern to the ejection amount setting section 612.

Fig. 7 is a diagram showing an example of the correction table information 73. In the correction table information 73, a plurality of "substrate types" are defined as processing conditions for forming the solder resist pattern. In the correction table information 73, one or more "copper thickness" are defined as the condition of each "substrate type". The copper thickness is a thickness of a conductive pattern made of copper included in the wiring substrate 9 before forming the solder resist (for example, a thickness of the conductive pattern 83 shown in fig. 4 and 5). Further, in the correction table information 73, one or more "surface treatments" are defined as conditions for the respective "copper thickness". The "surface treatment" is a condition indicating a treatment state of the surface 9a of the wiring substrate 9, and specifically includes polishing and grinding and a base.

In the correction table information 73, a plurality of "registration patterns" and "ejection amounts (dot area ratios)" are defined so as to correspond to 1-to-1 for each "surface treatment". As the "registration pattern", specifically, "lines" indicating a linear pattern, "SRO intersections" indicating a cross-like pattern, and "SRO intermediate lines" indicating a pattern formed in an intermediate region connecting intersections and intersections formed between SROs are defined. In addition, different line widths such as 70 μm, 100 μm, and 150 μm are defined for the "line".

In step S12 shown in fig. 4, the pattern specifying unit 611 first specifies the processing conditions (substrate type, copper thickness, surface treatment) to which the wiring substrate 9 to be processed is to be subjected. Further, the processing conditions of the wiring substrate 9 may be determined based on information provided to the control section 12 in advance by the user. The pattern specifying unit 611 searches the solder resist pattern data 71 for a registration pattern corresponding to the processing conditions defined in the correction table information 73, and if the registration pattern is found, specifies the size and position of the registration pattern.

The solder resist pattern data 71 is data representing an image of a pattern of the solder resist, and a value "1" indicating that ink is given or a value "0" indicating that ink is not given is defined for each pixel. Hereinafter, the value indicating whether or not ink is given will be referred to as "given value". The ejection rate setting unit 612 sets a given value for each pixel indicated by the solder resist pattern data 71. That is, the ejection rate setting unit 612 sets the dispensing value 1 for the pixel to which the ink is dispensed, and further sets the ejection rate per unit area. The ejection rate is a value corresponding to the thickness of the solder resist. That is, basically, the larger the ejection amount, the larger the film thickness.

Basically, the ejection rate setting unit 612 sets a predetermined reference ejection rate for the pixels to which the ink is to be applied. When the pattern specifying unit 611 specifies a registration pattern in the solder resist pattern data 71, the ejection rate setting unit 612 sets the ejection rate specified in the correction table information 73 for the pixel corresponding to the specified registration pattern. That is, the discharge amount setting unit 612 sets the discharge amount for the registration pattern determined by the pattern determining unit 611, based on the correction table information 73. Then, the ejection rate setting unit 612 generates ejection data 75 indicating the ejection rate set for each pixel, and stores the ejection data in the storage unit 62 (fig. 4: step S14).

The apparatus main body 11 receives the discharge data 75 from the control unit 12, and controls the head 3 and the movement mechanism 2 based on the discharge data 75. Specifically, a step of ejecting droplets of ink from the head unit 3 to the wiring substrate 9 and a step of relatively moving the head unit 3 with respect to the wiring substrate 9 in a direction parallel to the wiring substrate 9 are performed in parallel. Thereby, the ink is applied to the wiring substrate 9, and the pattern of the solder resist 92 corresponding to the solder resist pattern data 71 is formed (fig. 4: step S15).

As described above, in the correction table information 73 shown in fig. 7, the ejection amount is set for each registration pattern. In the pattern forming apparatus 1, the dot area ratio is used as the ejection amount. Therefore, the correction table information 73 uses the halftone dot area ratio as the ejection amount. In the example shown in fig. 7, the reference discharge rate is set to 60% using the halftone dot area ratio.

In the correction table information 73 shown in fig. 7, when a linear pattern (line) is focused, it is defined that the smaller the line width, the larger the discharge amount. This is because the smaller the line width, the thinner the film thickness becomes. In addition, in the case of polishing the surface of the wiring substrate 9, the discharge rate is set relatively large compared to the case of the base. This is because, when polishing is performed, the film thickness of the line pattern is more likely to be thinner than that of the base substrate. The discharge rate to the cross pattern (RRO intersection) is defined to be a value smaller than the discharge rate to the line pattern (for example, 50%). This is because the film thickness of the cross pattern tends to be relatively large.

Fig. 8 is a cross-sectional view schematically showing the wiring substrate 9 on which the solder resist films of plural kinds of patterns are formed. Further, the upper half of fig. 8 shows a case where each solder resist is formed with a certain reference ejection amount, and the lower half of fig. 8 shows a case where the ejection amount is changed based on the correction table information 73. The solder resists 911, 912, 913 are linear patterns, and the line widths are set to 70 μm, 100 μm, 150 μm. The solder resist 94 represents a cross-like pattern. The line width is formed to be larger in the order of solder resists 911, 912, 913. In addition, a broken line LN1 indicates the surface height (film thickness) of the solder resist film in design.

As shown in the upper part of fig. 8, in the case where the respective solder resists are formed at a certain reference ejection amount, the solder resist 913 having a relatively large line width has a sufficient thickness, and the solder resists 911, 912 having a small line width do not reach a desired thickness. In addition, the film thickness of the solder resist 94 is larger than the target film thickness. In contrast, in the correction table information 73, the linear pattern is set such that the smaller the line width, the larger the ejection amount. Therefore, the solder resist

films

911 and 912 having a relatively small line width can also be set to a target height. In the correction table information 73, a discharge rate (50%) smaller than a reference discharge rate (60%) is set for the intersecting pattern (SRO intersection). Therefore, the thickness of the solder resist 94 as the cross pattern can be matched to the designed thickness.

In the pattern forming apparatus 1, since the ejection rate of ink per unit area can be set according to the type of pattern, a solder resist having an appropriate film thickness can be formed on the wiring substrate 9 for each type of pattern.

<2. modification >

In the above-described embodiment, the registered pattern defined in the correction table information 73 is not limited to the registered pattern shown in fig. 7, and patterns having other sizes and shapes (for example, a curved pattern, a broken line pattern, and the like) are assumed.

In addition, in the above-described embodiment, the ejection amount is changed by changing the dot area ratio, but this is not essential. For example, the ejection amount can be changed by changing the size of ink droplets ejected from the head 3 and the ejection frequency per unit time.

The present invention has been described in detail, but the above description is illustrative in all aspects, and the present invention is not limited thereto. It is understood that numerous variations not illustrated can be devised without departing from the scope of the invention. The configurations described in the embodiments and the modifications may be appropriately combined or omitted unless contradictory to each other.

Claims

1. A pattern forming apparatus for forming a pattern of a solder resist on a wiring substrate,

the pattern forming apparatus has:

a holding unit for holding the wiring substrate;

a head unit configured to eject an ink droplet of a solder resist onto a surface of the wiring board by an ink jet method;

a moving mechanism that relatively moves the head portion with respect to the holding portion in a direction parallel to a surface of the wiring substrate;

an ejection data generating section that generates ejection data indicating an ejection amount of ink per unit area based on solder resist pattern data indicating a pattern of a solder resist; and

a control section that forms a pattern of a solder resist on the wiring substrate by controlling the head section and the moving mechanism based on the ejection data,

the ejection data generating section generates the ejection data in which different ejection amounts are set for each of different types of patterns included in the solder resist pattern data.

2. The pattern forming apparatus according to claim 1,

the pattern of the solder resist film includes: a first pattern having a line shape with a first line width; and a linear second pattern having a second line width smaller than the first line width,

the ejection data generation unit generates ejection data in which the ejection rate for the second pattern is set to a value larger than the ejection rate for the first pattern.

3. The pattern forming apparatus according to claim 1 or 2,

the pattern of the solder resist film comprises a cross-like third pattern,

the discharge data generation unit generates discharge data in which the discharge amount with respect to the third pattern is set to a value smaller than a predetermined reference discharge amount.

4. The pattern forming apparatus according to claim 2,

the pattern of the solder resist film comprises a cross-like third pattern,

the discharge data generation unit generates discharge data in which the discharge rate for the third pattern is set to a value smaller than the discharge rates for the first pattern and the second pattern.

5. The pattern forming apparatus according to any one of claims 1 to 4,

the pattern forming apparatus further includes a storage unit that stores correction table information that specifies discharge amounts per unit area for a plurality of types of patterns,

the ejection data generation unit includes:

a pattern determination section that determines a pattern registered in the fix-up table information in the solder resist pattern data; and

and a discharge rate setting unit that sets a discharge rate for the pattern specified by the pattern specifying unit, based on the correction table information.

6. A pattern forming method for forming a pattern of a solder resist on a wiring substrate,

the pattern forming method includes:

a step (a) of ejecting an ink droplet of a solder resist from a head onto a surface of the wiring substrate by an ink jet method;

a step (b) of relatively moving the head portion with respect to the wiring substrate in a direction parallel to a surface of the wiring substrate in the step (a); and

and (c) varying the amount of ink ejected per unit area in accordance with the type of pattern of the solder resist formed on the wiring substrate in the step (a).

7. A method for generating ejection data used when ejecting a droplet of solder resist ink from a head onto a wiring board by an ink jet method,

the ejection data generation method includes:

a step (A) for preparing solder resist pattern data formed on a wiring substrate; and

and (B) generating ejection data in which different ejection amounts per unit area are set for each of different types of patterns included in the solder resist pattern data.