JP4528895B2 - Pattern formation method - Google Patents

Description

  The present invention relates to a pattern forming method. More particularly, the present invention relates to a pattern forming method suitable for forming a pattern on a substrate using a paste in the manufacture of a circuit board or a display panel.

  Known methods for forming a pattern on a substrate include a method using screen printing (Patent Document 1) and a method using an offset printing method (Patent Document 2).

JP-A-11-172169 JP 2000-174485 A

  The screen printing method and the offset printing method, which are conventional pattern forming methods, print the paste through a screen mesh plate or intaglio roll, so that it is formed on the substrate due to variations in the amount transferred onto the substrate and sagging during curing. In particular, it is difficult to form a pattern having a height (t) / width (d) ratio (t / d) larger than 1 with high accuracy. An object of the present invention is to provide a pattern forming method capable of forming a pattern on a substrate with high accuracy.

The present invention has reached the present invention as a result of intensive studies to solve the above problems. That is, the pattern forming method of the present invention includes a step (1) of providing a photosensitive resin layer on a substrate surface, and then exposing and developing to form a recess on the substrate surface.
(R) rotation while the non-contact roll (R) is linearly moved at a moving speed (i) (mm / sec) in a direction horizontal to the substrate surface and in a direction perpendicular to the rotation axis of (R). (R) is rotated at a peripheral speed (v) (mm / second) larger than the moving speed (i) so that the rotating direction of the portion on the substrate side from the axis is opposite to the moving direction, and 10 to 10,000 Pa Filling the paste (P) into the recesses provided on the substrate surface under pressure (2 1 ),
A step (22) carried out after the step (21) and filled with a paste (P) in a recess provided on the substrate surface under atmospheric pressure;
And the step of curing the filled paste (P) (3)
The point including

  The pattern forming method of the present invention can form a pattern on a substrate with high accuracy. That is, the pattern forming method of the present invention has no variation in the amount of paste transferred to the substrate or sagging during curing, and the ratio (t / d) of the pattern height (t) to the width (d) is large (1). Pattern) can be formed with high accuracy.

<About step (1)>
Step (1) can be achieved by appropriately combining known methods. For example:
The substrate is not particularly limited as long as it is a substrate for forming a pattern, and is a laminated board for a printed wiring board {glass cloth base epoxy resin, glass cloth base polyimide resin, glass cloth base bismaleimide / triazine / epoxy resin. Etc. (including substrates conforming to JIS C 6480-1994 “General Rules for Copper-Clad Laminates for Printed Wiring Boards”)}, ceramic substrates, glass substrates, silicon wafers, plastic sheets, and the like are applicable. Note that a through hole or a bottomed hole may be formed in the substrate.

In order to provide the photosensitive resin layer on the substrate surface, a photosensitive resin is used.
The photosensitive resin is not particularly limited as long as it is a photosensitive resin that can be exposed and developed, and a solvent-developable photoresist {photosensitive resin composition containing (meth) acrylate and a photopolymerization initiator}, alkali developing type Liquid photoresist {photosensitive resin composition containing a (meth) acrylate having a carboxy group and the like and a photopolymerization initiator} and an alkali development type film-like photoresist {alkali-soluble binder, (meth) acrylate and a photopolymerization initiator A dry film obtained by forming a photosensitive resin containing a film into a film, etc.} {For example, “Photopolymer Handbook” (published on June 26, 1989, edited by Photopolymer Society). } Etc. can be used.
In the present invention, “(meth) acrylic” means “acrylic” and “methacrylic”.

In order to provide the photosensitive resin layer on the substrate surface, when the photosensitive resin is in a liquid state, a roll coating method, a dip method, a spin coating method, a screen printing method, and a spray coating method {for example, “illustrated photofabrication” (general (Published on July 10, 1986). } Etc. are applicable.
On the other hand, when the photosensitive resin is in a film form, it is described in a laminating method {for example, “Multilayer printed wiring board manufacturing method” (issued May 31, 1993, Nikkan Kogyo Shimbun). } Etc. are applicable.
When the photosensitive resin contains a solvent (such as water and an organic solvent), it is preferable to remove the solvent after coating, printing or laminating.
The thickness of the photosensitive resin layer is preferably equal to or exceeds the thickness of the target pattern to be formed, and more preferably about 1.0 t to 1.2 t when the thickness of the target pattern is t (mm). Particularly preferably, it is about 1.0 to 1.1 t.

  In the exposure of the photosensitive resin layer, when the photosensitive resin is a negative type (the exposed portion is cured), a photomask in which the target pattern portion is shielded from light is placed on the photosensitive resin layer (contact or (Non-contact) or may be carried out by irradiating active energy rays {for example, described in “Photopolymer Handbook” (published on June 26, 1989, edited by Photopolymer Society). } Alternatively, portions other than the target pattern may be directly drawn with an active energy ray and exposed (direct drawing method described in Japanese Patent No. 3030102).

On the other hand, when the photosensitive resin is a positive type (the exposed portion is developed and removed), a photomask is provided on the photosensitive resin layer so that light is shielded except for the target pattern (contact or non-contact). Further, it may be carried out by irradiating active energy rays {described in “Photopolymer Handbook” (published on June 26, 1989, edited by Photopolymer Society). }, The portion of the target pattern may be directly drawn with active energy rays and exposed {for example, described in JP-A-2000-56458. }.
In addition, as an active energy ray, ultraviolet rays (wavelength 14 to 400 nm), visible light (wavelength 400 to 800 nm), an electron beam, and the like are used.

Development is achieved by a usual method, for example, by dissolving and removing (spraying and / or dipping, etc.) the photosensitive resin in the unexposed part (in the case of negative type) or exposed part (in the case of positive type) with a developer. The
The developer is not particularly limited, but a hydrocarbon solvent (such as toluene and xylene), a glycol ether solvent (such as diethylene glycol monoethyl ether acetate and triethylene glycol dimethyl ether), a ketone solvent (such as methyl ethyl ketone and methyl isobutyl ketone) and an aqueous solution (carbonic acid). Sodium, sodium hydrogen carbonate, sodium hydroxide and / or an alkaline aqueous solution such as ammonium hydroxide, etc.) can be used.
It is preferable to wash and dry after development.

Since the pattern is formed in the recess formed in step (1), the size of the recess is determined by the size (width, thickness, length) of the pattern.
Further, since the formation accuracy of the recesses in the step (1) is directly affected by the formation accuracy of the pattern, providing the photosensitive resin layer with high accuracy improves the accuracy of the pattern.
The photosensitive resin layer (including the recesses) may be removed after the pattern is formed, or may be left as it is.

<About step (2)>
In the step (2), the non-contact roll (R) is linearly moved at a moving speed (i) (mm / second) in the horizontal direction with respect to the substrate surface and in the vertical direction with respect to the rotation axis of (R). (R) is rotated at a peripheral speed (v) (mm / sec) larger than the moving speed (i) so that the rotating direction of the portion on the substrate side from the rotating shaft of (R) is opposite to the moving direction. And the step of filling the paste (P) into the recesses provided on the substrate surface, the movement speed (i) and the peripheral speed (v) are preferably represented by the formula (1), Preferably, the expression (2) is satisfied.
Here, the linear movement of the non-contact roll (R) may be performed by relatively linearly moving the non-contact roll (R) and the substrate. Accordingly, the non-contact roll (R) may move with respect to the stopped substrate, or the substrate moves with respect to the non-contact roll (R) that is stopped (rotating). Good.

{(I) × 10} ≧ (v) ≧ {(i) × (1.2 + 0.1 × t / d)} (1)

{(I) × 10} ≧ (v) ≧ {(i) × (1.5 + 0.1 × t / d)} (2)

T is It represents the height (mm) of the pattern to be formed, and is usually about 0.001-1, preferably about 0.005-0.5, more preferably about 0.01-0.1.
Further, d represents the minimum pattern width (mm) to be formed, and is usually about 0.1 t to 10 t, preferably about 0.2 t to 5 t, and more preferably about 0.3 t to 2 t.

  When the relationship between the moving speed (i) and the peripheral speed (v) is as described above, unfilled paste (P), entrainment of voids, and the like are further suppressed, and a pattern with higher accuracy can be formed. That is, as the ratio (t / d) between the pattern thickness (t) and the minimum pattern width (d) increases, the recesses are less likely to be filled. Is preferred. On the other hand, if the peripheral speed (v) is excessively increased, it is likely to cause unfilling or void entrainment, and therefore it is preferable to decrease the peripheral speed (v). In order to solve this contradictory matter, the relationship between the moving speed (i) and the peripheral speed (v) is preferably such that the peripheral speed (v) is larger than the moving speed (i), and more preferably the formula (1) And particularly preferably the expression (2) is satisfied.

  The non-contact roll (R) is not limited in speed as long as it can move linearly while keeping the rotation axis of the non-contact roll (R) in the horizontal direction with respect to the substrate surface, but the non-contact roll (R) linear movement speed ( i) (mm / sec) is preferably 5 to 100, more preferably 10 to 70, and particularly preferably 20 to 50. Within this range, the occurrence of unfilled or void entrainment can be further suppressed.

The movement direction of the non-contact roll (R) is perpendicular to the rotation axis of (R), but the angle between the movement direction and the rotation axis is not limited to 90 ° but includes 60 to 120 °. It is a waste.
The rotation direction of the non-contact roll (R) is a direction in which the rotation direction of the portion on the substrate side with respect to the rotation axis is opposite to the movement direction, that is, the rotation direction so that the non-contact roll (R) rolls in the linear movement direction. is there. This opposite direction (the direction in which the rotation direction of the portion closer to the substrate than the rotation axis is the same as the movement direction, that is, the non-contact roll (R) rolls in the direction opposite to the linear movement direction. If it rotates in the direction of rotation), the object of the present invention cannot be achieved.

  The peripheral speed (v) (mm / second) of the non-contact roll (R) is represented by {Roll angular velocity (ω)} × {(Roll radius (r)}, and a range satisfying the formula (1) is preferable. More preferably, it is a range satisfying the formula (2) The peripheral speed when a roll having a diameter of 50 mm makes one revolution per second is 25 mm × 6.28 rad / sec = 157 mm / sec.

The non-contact roll (R) is preferably provided with a doctor {paste (P) scraping squeegee}. The doctor is arranged on the side opposite to the moving direction of the non-contact roll (R) so as to be close to or in contact with the non-contact roll (R) and linearly moves together with the non-contact roll (R). Moreover, it is preferable to have a plane having an angle of 10 to 30 ° with respect to the substrate on the moving direction side of the distal end portion of the doctor, and this angle is more preferably about 15 ° (see FIGS. 1 and 2). ).
The presence of the doctor further reduces unfilled recesses and void entrainment. That is, the doctor has a function of moving the paste (P) collected by the rotation of the non-contact roll (R) together with (R) in the moving direction {no paste (P) is left on the substrate surface}. Further, the paste (P) scraped between the doctor, the non-contact roll (R) and the substrate has a function of bringing the pressure into a pressurized state {the pressure is applied by the rotation of the non-contact roll (R), The action of pushing the paste (P) into the recesses occurs}. When a doctor is arranged, guards (weirs) are provided at both ends of the “doctor, non-contact roll (R) and substrate” so that a sealed space is formed between the doctor, non-contact roll (R) and the substrate. Plate) (eg, FIGS. 9 and 10). This guard moves linearly together with the non-contact roll (R) and the doctor.

  The shortest distance (mm) between the photosensitive resin layer and the surface of the non-contact rotating roll is preferably from 0.1 to 5, more preferably from 0.3 to 3, particularly preferably from 0.5 to 5 from the viewpoint of filling properties. 1.5. Within this range, the occurrence of unfilling and void entrainment is further suppressed, and a more accurate pattern can be formed.

The step (2) includes a step (21) of filling under a pressure of 10 to 10000 Pa and a step (22) of performing after step (21) and filling under atmospheric pressure from the viewpoint of filling properties. It is preferable that a temporary curing step (23) of the paste (P) is included between the step (21) and the step (22).
The atmospheric pressure (Pa) in the filling step (21) is preferably 10 to 10,000, more preferably 50 to 5,000, particularly preferably 100 to 1,000 from the viewpoint of filling properties. Within this range, the occurrence of unfilled or void entrainment is further suppressed. Further, when the resin paste filled in the filling step (21) is returned to the atmospheric pressure, a dent may be generated due to the volume reduction. In order to fill the dent, the step of filling under the atmospheric pressure ( 22) is preferably provided. Further, the temporary curing step (23) is preferable because the generation of dents due to curing shrinkage can be further prevented.
In addition, when content of volatile components, such as a solvent, paste (P) exceeds 10 weight% based on the weight of paste (P), it is preferable to perform a process (2) under atmospheric pressure.
The temporary curing step (23) includes heat treatment when the paste (P) is a thermosetting resin, irradiation treatment with active energy rays such as ultraviolet rays when the paste is an active energy ray curable resin, and cooling treatment when the paste is a thermoplastic resin. And / or a drying process may be performed.

  Steps (21) and (22) may be repeated a plurality of times to prevent unfilling or insufficient filling. For example, after performing the filling process (21) twice under an atmosphere of 150 Pa, the process (22) may be performed once after returning to atmospheric pressure.

The paste (P) is not limited as long as it is a paste for forming a pattern, and includes a conductive paste, a dielectric paste, an insulating paste, and the like.
The storage elastic modulus (G ′) (unit: Pa) of the paste (P) is preferably 10 to 10,000, more preferably 20 to 5,000, particularly preferably 50 to 50 from the viewpoint of filling property (easy to fill). 3000.
Within this range, the occurrence of unfilling and void entrainment can be further suppressed, and a more accurate pattern can be formed.

The storage elastic modulus (G ′) (unit: Pa) is described in “Rheological Engineering and its Applied Technology”, Fuji Techno System Co., Ltd., January 12, 2001, first edition, first printing, pages 204-206. It is a value measured at the same temperature as that of filling using a viscoelasticity measuring device (for example, HAAKE Rheo Stress RS75) that can be measured by a stress control method, and is obtained as follows.
A measurement sample is sandwiched between measurement jigs {between the upper cone disk and the lower flat disk (see FIG. 3, the arrow in FIG. 3 indicates the direction of sine vibration)}, and perpendicular to the upper surface of the upper cone disk By applying a sinusoidal vibration while changing the angular velocity (ω) (unit: rad / sec) around the central axis, a stress (σ) (unit: Pa) is applied to the measurement sample, and the resulting strain (ε ) (Unit: rad) and phase angle (δ) (unit: rad).
Then, in accordance with JIS K7244-1-1998 “Plastics—Test Method for Dynamic Mechanical Properties Part 1: General Rules”, the complex elastic modulus is calculated from the ratio (σ / ε) of stress (σ) to strain (ε). After calculating (G ^* = σ / ε) (unit: Pa), the storage elastic modulus (G ′) is calculated from the formula {G ′ = G ^* × cos δ} as the real part of the complex elastic modulus (G ^* ). To do.
The storage elastic modulus at the angular velocity (ω) corresponding to the peripheral velocity (v) of the non-contact roll (R) used at the time of filling is read from the “angular velocity-storage elastic modulus curve” obtained by plotting the calculation result. The peripheral speed (v) and the angular speed (ω) are converted by the following equation.
Angular velocity (ω) = circumferential velocity (v) / radius (r) of roll (R)

The measurement conditions are shown below.
Measuring device: Dynamic viscoelasticity measuring device (for example, Rheostress RS75 manufactured by HAAKE)
Measuring jig: 20mm diameter aluminum disk (upper cone disk angle 2 degrees)
Sample volume: 0.5mL
Rotational shear stress: 10Pa
Measurement temperature: Same temperature as filling (usually 20-30 ° C)
Angular velocity: 0.628-628 rad / sec

As the paste (P), a mixture of the filler (F) and a curable resin and / or a thermoplastic resin is used.
As the filler (F), known inorganic fillers and organic fillers can be used.
Inorganic fillers include oxides {silica (silicon oxide), titania (titanium oxide), alumina (aluminum oxide), zirconia (zirconium oxide), barium titanate, glass, etc.}, carbonate {calcium carbonate, etc.}, metal { Copper, silver, gold, tungsten, solder, iron, nickel, and composites thereof (including mixed molded bodies and solid solutions thereof). Of these, silica, alumina, glass, copper and silver are preferred.
Examples of the organic filler include acrylic resin powder, epoxy resin powder, fluororesin powder, polyether sulfone resin powder, silicone resin powder, and nylon resin powder. Of these, acrylic resin powder is preferred.

The content (% by weight) of the filler (F) is based on the total weight of the filler (F), the curable resin, and the thermoplastic resin from the viewpoint of the thermal expansion coefficient and pattern performance (such as resistivity and dielectric constant). 30 to 95 is preferable, more preferably 50 to 90, and particularly preferably 60 to 85. Within this range, unfilled recesses and voids are further suppressed.
The volume average particle diameter (μm) of the filler (F) is preferably 0.1 to 30, more preferably 0.5 to 20, and particularly preferably 1.0 to 10. Within this range, unfilled recesses and voids are further suppressed.
The volume average particle diameter is measured by a laser diffraction particle size distribution measuring apparatus having a measurement principle based on JIS Z8825-1-2001 “Particle Size Analysis—Laser Diffraction Method” (for example, product name SALD-1100 manufactured by Shimadzu Corporation). Measured in

  The shape of the filler (F) is spherical, teardrop-shaped, angular, dendritic, flaky, granular, irregular, needle-like, fibrous (JIS Z2500: 2000 “Powder and Gold Terms”) 4. Terms and Definitions 4) Particle shape of powder) may be used, but spherical, teardrop-like, flake and granular are preferable, and spherical is more preferable from the viewpoint of the filling property of the recesses.

  Although a filler (F) may be used independently, you may use it in combination of 2 or more type. For example, a combination of spherical silica, spherical copper powder, and granular calcium carbonate.

Examples of the curable resin include a thermosetting resin and an active energy ray curable resin.
As the thermosetting resin, an epoxy resin or a polyimide resin described in JP-A-2004-149758 can be used.
Examples of the active energy ray curable resin include an epoxy resin described in JP-A No. 2004-149758, a composition comprising a compound having a polymerizable double bond described in JP-A No. 2001-330951, and a photo radical generator. Can be used.

Of the thermosetting resins, a liquid epoxy resin (consisting of a liquid epoxide and a curing agent) is preferable.
The liquid epoxide means an epoxide that is liquid at 25 ° C., but also includes an epoxide that is liquid at 25 ° C. together with a liquid epoxide that becomes liquid as a whole. Of the liquid epoxides, bisphenol F-type epoxides, bisphenol A-type epoxides and glycidylamine-type epoxides are preferred, bisphenol F-type epoxides and bisphenol A-type epoxides are more preferred, and bisphenol F-type epoxides are particularly preferred. These liquid epoxides may be one kind or a mixture of two or more kinds.
Of the curing agents, phenol compounds, organic acid anhydrides and amine compounds, dicyandiamide, imidazole compounds, organic acid hydrazide compounds, and solid dispersed amine adducts (latent curing agents) are preferred, and phenol compounds and organic acid anhydrides are more preferred. An imidazole compound. These curing agents may be used alone or in combination of two or more.

The active energy ray-curable resin is preferably a composition comprising a compound having a polymerizable double bond and a photo radical generator.
Among compounds having a polymerizable double bond, an ester of polyhydric alcohol or an alkylene oxide adduct of polyhydric alcohol and (meth) acrylic acid {dipentaerystol hexa (meth) acrylate, ethoxylated trimethylolpropane tri ( Meth) acrylates}, urethane (meth) acrylates {reactants of polyvalent isocyanates with (meth) acrylates having active hydrogen groups (hydroxy groups, carboxy groups, amino groups, etc.)} and epoxy (meth) acrylates {multifunctional Reaction product of epoxide and (meth) acrylic acid: bisphenol A diglycidyl ether di (meth) acrylate, phenol novolac (meth) acrylate, etc.} is preferable, and more preferably, polyhydric alcohol or alkylene oxide adduct of polyhydric alcohol; (Me ) An ester of acrylic acid.
These compounds having a polymerizable double bond may be used alone or in combination of two or more.

  Examples of the photo radical generator include diphenyl- (2,4,6-triethylbenzoyl) phosphine oxide, 2,2-dimethoxy-2-phenylacetophenone, dimethylhydroxyacetophenone, 1-hydroxy-cyclohexyl-phenyl-ketone, 2- Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone and 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one are preferred. These photo radical generators may be used alone or in combination of two or more.

These curable resins may be used alone or in combination of two or more.
In the case of using a curable resin, the content (% by weight) of the curable resin is preferably 5 to 233, more preferably 11 to 100, and particularly preferably 18 to 67, based on the weight of the filler (F). . Within this range, unfilled recesses and voids are further suppressed.

Examples of the thermoplastic resin include polyethylene, polypropylene, polybutadiene, polyisoprene, styrene-butadiene copolymer, styrene-isoprene copolymer, acrylonitrile-butadiene copolymer, ethyl cellulose, polyamide, polyvinyl butyral, polymethyl methacrylate, and rosin. Can be used.
A thermoplastic resin is dissolved in a solvent and used as a liquid, or when filled, it is melted and liquefied at a temperature equal to or higher than its melting point and returned to room temperature (about 25 ° C.) to be solidified. is there.
Therefore, in the latter case, if this melting point is too high, there are concerns about problems such as resin degradation and heat resistance of the apparatus. Therefore, the melting point (° C.) of the thermoplastic resin is preferably 100 to 250, more preferably 120 to 200, particularly preferably 140 to 180. On the other hand, in the former case, the melting point of the thermoplastic resin is not limited, and those having a high melting point can be used. In the former case, the thermoplastic resin is dissolved in a solvent to be liquefied, and after filling the recess, the solvent is distilled off to cure (solidify).

  When a thermoplastic resin is used, the content (% by weight) of the thermoplastic resin is preferably 5 to 233, more preferably 11 to 100, and particularly preferably 18 to 67, based on the weight of the filler (F). . Within this range, unfilled recesses and voids are further suppressed.

  When using a curable resin and a thermoplastic resin, the content (% by weight) of the curable resin is preferably 40 to 99, more preferably 50 to 95, based on the total weight of the curable resin and the thermoplastic resin. Especially preferably, it is 60-90. Within this range, unfilled recesses and voids are further suppressed. In this case, the content (% by weight) of the thermoplastic resin is preferably 1 to 60, more preferably 5 to 50, and particularly preferably 10 to 40 based on the total weight of the curable resin and the thermoplastic resin. It is. Within this range, unfilled recesses and voids are further suppressed.

  To the paste (P), an additive usually used {antifoaming agent, dispersing agent, organic / inorganic colorant, flame retardant and / or thixotropic agent} may be added. When the antifoaming agent is added, the content (% by weight) is preferably 0.05 to 5, more preferably 0.5 based on the total weight of the filler (F), the curable resin and the thermoplastic resin. -3, particularly preferably 1-2. In the case of adding a dispersant, the content (% by weight) is preferably 0.01 to 5, more preferably 0.03 to 2, based on the total weight of the filler (F), the curable resin and the thermoplastic resin. Especially preferably, it is 0.05-1. When the organic / inorganic colorant is added, the content (% by weight) is preferably 0.01 to 5, more preferably 0, based on the total weight of the filler (F), the curable resin, and the thermoplastic resin. 0.03 to 2, particularly preferably 0.05 to 1. When the flame retardant is added, the content (% by weight) is preferably 0.5 to 10, more preferably 0.8 to, based on the total weight of the filler (F), the curable resin, and the thermoplastic resin. 8, particularly preferably 1-5. When the thixotropic agent is added, the content (% by weight) is preferably 0.01 to 5, more preferably 0.03, based on the total weight of the filler (F), the curable resin and the thermoplastic resin. ˜2, particularly preferably 0.05˜1.

The paste (P) may contain a solvent. However, when a vacuum is applied during filling, the volatile components (solvents, etc.) contained in (P) in the degree of vacuum and temperature during filling are less than 10% by weight in order to prevent the generation of voids. Preferably, it is 5% by weight or less, particularly preferably 0.5% by weight or less. Volatile components conform to JIS K0067-1992 “Method for testing weight loss and residue of chemical products” 4.1.4 (1) Method 1 Heat drying under atmospheric pressure (105 ± 2 ° C., 2 hours) Measured. Such solvents include water and organic solvents.
As the organic solvent, hydrocarbon solvents (such as toluene and xylene), glycol ether solvents (such as diethylene glycol monoethyl ether acetate and triethylene glycol dimethyl ether) and ketone solvents (such as methyl ethyl ketone and methyl isobutyl ketone) can be used.
When the solvent is contained, the content (% by weight) of the solvent is preferably 0.1 to 10, more preferably 0.1 to 5, based on the total weight of the filler (F), the curable resin, and the plastic resin. Especially preferably, it is 0.1-1.

  The storage elastic modulus (G ′) of the paste (P) can be adjusted by the content of the filler (F), the volume average particle diameter and / or shape, etc., but the curable resin, additive (particularly thixotropic agent) and / or Or it can adjust also with the kind, content, etc. of a solvent.

  Paste (P) is commercially available, Nopcocure SVC-710 (thermosetting resin paste) manufactured by San Nopco Co., Ltd., Nopcocure SVC-720 (thermosetting copper paste); YSM2002 (capped hole filling) AE1650 (thermosetting conductive paste) manufactured by Tatsuta System Electronics; YPT340 (dielectric glass paste) manufactured by Asahi Glass; NP-4732 (fired conductive silver paste) manufactured by Noritake Co .; Examples include LF101-15 (solder paste) manufactured by Tamura Kaken.

<Regarding Step (3) for Curing Filled Paste (P)>
Step (3) includes heat treatment step (31) {when paste (P) is a thermosetting resin}, active energy ray irradiation treatment step (32) {in the case of active energy ray curable resin}, and cooling treatment. Alternatively, it is achieved by a solvent drying step (33) {in the case of a thermoplastic resin} or the like. Note that when the substrate is made of a material having high heat resistance {further including a metal or metal oxide in the paste (P)}, a baking treatment {firing step (34)} may be performed.

In the heat treatment step (31), the thermosetting resin can be cured by treatment at 80 to 300 ° C. in a circulation-type heating furnace, a far-infrared heating furnace, a hot plate, or the like.
In the irradiation treatment step (32), the active energy curable resin can be cured by irradiating the active energy ray with ultraviolet rays (wavelength 14 to 400 nm), visible light (wavelength 400 to 800 nm), electron beam or the like.
In the cooling treatment or solvent drying step (33), the molten thermoplastic resin is cooled to a temperature below the melting point to be solidified, or dissolved in the solvent and the solvent in the paste in the liquid state is 50 to 150. It can be volatilized at a temperature of 0 ° C. to form a solid state (solidified).
In the firing step (34), the resin component in the paste can be volatilized or decomposed at a high temperature of 200 to 1000 ° C., and the inorganic filler can be fused and cured.
You may implement these processes (31)-(34) combining as needed.

After the step (3), a flattening step of polishing and removing the thin film-like residue of the cured resin remaining on the photosensitive resin surface may be provided. The polishing step can be performed using a non-woven cloth roll buff or the like.
After step (3), step (2) may be performed again to fill the recesses with paste. When the filling is not completely filled with respect to the depth of the concave portion formed of the photosensitive resin in the first step (2), it may be preferable because the filling can be completely carried out after the second time. In the second step (2), the paste may be filled using a different type of paste from that used in the first step.

<Regarding Step (4) for Removing Photosensitive Resin>
The pattern forming method of the present invention preferably includes a step (4) of removing the photosensitive resin after the step (3).
In addition, when a baking process (34) is included in a process (3), a process (4) is unnecessary. That is, it is preferable that the pattern forming method of the present invention includes a step (4) of removing the photosensitive resin after the step (3), or includes a baking step (34) in the step (3).
The removal of the photosensitive resin can be performed by immersion in a stripping solution such as dimethylformamide, N-methylpyrrolidone, N, N-dimethylacetamide, γ-ptyrolactone, aqueous sodium hydroxide or aqueous diethanolamine, or by a spray method, or If the substrate is nonflammable, it may be removed by firing.
When there is no problem even if the photosensitive resin remains on the substrate, or when it is used as it is as a protective film, the step (4) is not necessary.
If the paste needs to be completely cured after step (4), a post-curing step (5) may be further performed. When step (4) is not performed, step (5) may be performed after step (3) or after the planarization step.

By applying the pattern forming method of the present invention, a circuit board or the like can be manufactured by using a conductive paste as the paste (P) and forming a pattern (conductive circuit pattern) on the substrate.
Also, a display panel or the like can be manufactured by using a conductive paste as the paste (P) and forming electrodes and electromagnetic wave shields on the substrate.
Further, a glass paste is used as the paste (P), and a display (rib or partition pattern) is formed to produce a display panel.
Further, a circuit board and / or a display panel manufactured using the pattern forming method of the present invention is incorporated, and an electronic device (mobile phone, radio, television, personal computer, general-purpose computer, facsimile, copying machine, video camera, Digital cameras, game machines, telephone exchanges, car navigation systems, etc.).

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the following examples.
In the examples, the following filling device, paste, and substrate were used.
<Filling device (see FIGS. 4 to 6)>
In the filling device, a substrate fixing base (4), a doctor (6), a non-contact roll (7) and a guard (14) are arranged in a vacuum chamber (3). The doctor (6), the non-contact roll (7), and the guard (14) are integrated to move in the horizontal direction with respect to the substrate surface and in the direction perpendicular to the rotation axis of the non-contact roll (7) (i). ) (Mm / sec) can be moved linearly.
The doctor (6) can scrape off excess paste remaining on the substrate after the paste (8) is filled in the recesses of the substrate. The inside of the vacuum chamber can be depressurized.
Further, the non-contact roll (7) is such that the rotation direction of the substrate side portion with respect to the rotation axis of the non-contact roll (7) is opposite to the movement direction of the doctor (6) and the non-contact roll (7). , And can be rotated at a peripheral speed (v) (mm / sec). Moreover, the space | interval of a non-contact roll (7) and the photosensitive resin layer surface can be set arbitrarily.
The surface material of the non-contact roll (7) is made of stainless steel, and its size is 50 mm in diameter and 550 mm in length. The doctor (6) is made of urethane resin having a hardness of 70 degrees, and has a width of 70 mm, a thickness of 20 mm, and a length of 510 mm, and the tip has the shape shown in FIG.
The guard (14) can prevent the paste (P) from protruding from both ends of the doctor (6) and the non-contact roll (7). The guard (14) is a polyacetal plate (height 80 mm, width 100 mm, thickness 20 mm) provided with a through hole with a diameter of 51 mm at the center (the through hole is a non-contact roll (7) and a substrate fixing base) It exists in the position which becomes 0.1 mm between (4)}. And the terminal part of a non-contact roll (7) is inserted in this hole. The guard (14) is in contact with the upper surface of the substrate fixing base (4) and both end portions of the doctor (6).

<Paste>
With the composition and amount used (parts by weight) shown in Table 1, with a planetary mixer (trade name “PLM-50”, manufactured by Inoue Seisakusho Co., Ltd., revolution speed: 20 rpm, temperature: 22 ° C., time: 20 minutes) After premixing, pastes P1 to P1 were kneaded with three rolls (trade name “HHC-178X356”, manufactured by Inoue Seisakusho Co., Ltd., pressure between rolls: 3 MPa, temperature: 22 ° C., number of passes: 2 times). P8 was obtained.
The storage elastic modulus (G ′) of the pastes P1 to P8 was measured at 23 degrees Celsius (filling operation temperature) using a viscoelasticity measuring device (Rheostress RS75 manufactured by HAAKE). Got. Next, the storage elastic modulus at the angular velocity (Tables 3 to 6: 0.628, 3.14, 6.28, 31.4, 62.8) corresponding to the peripheral velocity of the non-contact roll (7) used at the time of filling is determined. Readings are shown in Table 1.

Glass powder A: ASF110 (volume average particle diameter 6 μm) manufactured by Asahi Glass Co., Ltd.
Glass powder B: ASF1340 (volume average particle diameter 1.2 μm) manufactured by Asahi Glass Co., Ltd.
Copper powder: SRC-Cu15 (volume average particle diameter 12 μm spherical copper powder) manufactured by Fukuda Metal Foil Powder Co., Ltd.
Silver powder: manufactured by Fukuda Metal Foil Powder Co., Ltd. Mixture of spherical silver powder (50 wt%) having a volume average particle diameter of 4 μm and flaky silver powder (50 wt%) having a volume average particle diameter of 3 μm Epicoat 807: Bisphenol F type epoxide {Japan Epoxy Resin Co., Ltd. Epicoat 807}
Curing agent: Imidazole 2MZ-A (2,4-diamino-6- [2′-methylimidazolyl- (1 ′)]-ethyl-s-triazine) manufactured by Shikoku Kasei Co., Ltd.
DPE-6: Dipentaerystol hexaacrylate {Kyoeisha Co., Ltd. DPE-6A}
Photoradical generator: Irgacure 184, manufactured by Ciba Specialty Chemicals
Antifoaming agent: KF6001 (Carbinol-modified silicone) manufactured by Shin-Etsu Chemical Co., Ltd.
Thixotropic agent: Disparon 3900 (Polyamide) manufactured by Enomoto Kasei Co., Ltd.
Thermoplastic resin: butyl acetate cellosolve solution of ethyl cellulose (40% by weight)

<Board>
Table 2 shows the material, size, and thickness of the substrate used.

<Example 1>
Examples will be described with reference to FIGS.
Process (1)
(A) Formation of photosensitive resin layer [FIG. 7 (a)]
A photosensitive resin {dry film type photoresist “Nopcocure F-1540 (manufactured by San Nopco Co., Ltd.)”} having a film thickness of 40 μm was laminated on the substrate (5) {substrate K1} to form a photosensitive resin layer.
(B) Exposure [FIG. 7 (b), arrows indicate the irradiation direction of ultraviolet rays. ]
Ultraviolet light (3 kw ultrahigh pressure mercury lamp) was irradiated (500 mJ) through a photomask (12) that shielded the pattern formation portion.
(C) Development {FIG. 7 (c)}
A glycol ether developer “SN Solver 861 (manufactured by San Nopco Co., Ltd.)” whose temperature is adjusted to 30 ° C. is sprayed at a pressure of 0.2 MPa for 90 seconds to develop the unexposed portion (elution treatment), and the photosensitive on the substrate A recess (11) was formed in the conductive resin layer. At this time, the height of the concave portion was 40 μm and the minimum width was 20 μm. (This value is shown in Table 3 together with other examples.) }.

Process (2)
(D) Filling {FIGS. 4-6, 7 (d)}
The following operation was performed in a room whose temperature was adjusted to 23 ± 2 ° C.
The substrate (5) in which the concave portion (11) is formed is filled in the substrate fixing table (4) of the filling device {the depression of the substrate fixing table (4) has the same depth as the total thickness of the substrate and the photosensitive resin layer. } Was fixed by fitting. Next, the paste P1 is placed on the edge of the substrate, and the inside of the vacuum chamber (3) is depressurized to 150 Pa. Then, the moving speed of the non-contact roll (7) is 20.0 mm / sec, and the peripheral speed is 78.5 mm / sec. Second, the distance between the non-contact roll and the photosensitive resin layer was 0.5 mm, and the angle between the doctor and the photosensitive resin layer was 15 degrees, and the recess (11) was filled with the paste P1.
After completion of filling, the same conditions as above except that the pressure in the vacuum chamber (3) is returned to atmospheric pressure and then changed to atmospheric pressure, and the angle between the doctor and the photosensitive resin layer is changed to 40 degrees. The filling process was performed at (moving speed, peripheral speed, spacing between the non-contact roll and the photosensitive resin layer) to obtain a filled substrate.

Step (3)
(E) Curing {FIG. 7 (e)}
The filled substrate was heated with a circulating dryer at 130 ° C. for 30 minutes to obtain a cured substrate.

Process (4)
(F) Removal of photosensitive resin layer {FIG. 7 (f)}
After the photosensitive resin layer is peeled off by spraying 40 ° C. N-methylpyrrolidone at a pressure of 0.3 MPa for 3 minutes on a cured substrate, 20 ° C. deionized water is sprayed at a pressure of 0.1 MPa for 1 minute and washed with water. Then, the substrate was dried at 80 ° C. for 30 minutes with a circulating dryer to obtain a pattern-formed substrate 1.
And 100 places were selected at random about the formed pattern, and the number of occurrence of defects was evaluated as follows.

<Number of filling defects>
Using a tabletop hand cutter (trade name “Hand Cutter PC-300” manufactured by Sanhayato Co., Ltd.), the pattern-formed substrate is cut perpendicularly to the substrate surface, and a polishing / polishing machine (trade name “Struers Planopol-3”, round The cross section of the pattern was smoothed by polishing the cut surface using the present invention. And this pattern cross section was observed with the microscope (100-times multiplication factor), and pattern height, pattern width, and the number of voids in a pattern were measured. The accuracy was evaluated according to the following criteria. These results are shown in Table 3.
○ Good accuracy (The deviation of the pattern height and pattern width from the design value was less than 5%.)
X Inaccuracy (the deviation of the pattern height and pattern width from the design values was 5% or more.

<Examples 2-45>
Table 3 shows the substrate K1, the paste P1, the pressure in the vacuum chamber of 150 Pa and atmospheric pressure, the moving speed of 20.0 mm / sec, the peripheral speed of 78.5 mm / sec, and the distance between the non-contact roll and the substrate of 0.5 mm. Resin-filled substrates 2 to 45 (patterned substrates 2 to 45) were obtained in the same manner as in Example 1 except that the contents were changed. Table 3 shows the accuracy and the number of voids evaluated in the same manner as in Example 1.

<Examples 46 to 57>
Table 4 shows the substrate K1, the paste P1, the pressure in the vacuum chamber of 150 Pa and atmospheric pressure, the moving speed of 20.0 mm / sec, the peripheral speed of 78.5 mm / sec, and the distance between the non-contact roll and the substrate of 0.5 mm. Resin-filled substrates 46 to 57 (pattern forming substrates 46 to 57) were obtained in the same manner as in Example 1 except that the contents were changed and the step (3) was changed as follows. The accuracy and the number of voids evaluated in the same manner as in Example 1 are shown in Table 4.
Step (3)
(E) Curing {FIG. 7 (e)}
The cured substrate was obtained by irradiating the filled substrate (surface filled with the paste P1) with 1 J / cm ² of ultraviolet rays (160w metal halide lamp).

<Examples 58 to 63>
Table 5 shows the substrate K1, the paste P1, the pressure in the vacuum chamber of 150 Pa and atmospheric pressure, the moving speed of 20.0 mm / second, the peripheral speed of 78.5 mm / second, and the distance between the non-contact roll and the substrate of 0.5 mm. Resin-filled substrates 58 to 63 (patterned substrates 58 to 63) were obtained in the same manner as in Example 1 except that the contents were changed and the step (3) was changed as follows. Table 4 shows the accuracy and number of voids evaluated in the same manner as in Example 1.
Step (3)
(E) Curing {FIG. 7 (e)} and (f) Photosensitive resin layer removal {FIG. 7 (f)}
The filled substrate is heated for 30 minutes with an air circulation dryer at 80 ° C. and then baked in an electric furnace at 550 ° C. to cure the resin paste and remove the photosensitive resin layer to obtain a cured substrate. It was.

<Comparative Examples 1-7>
Table 6 shows the substrate K1, the paste P1, the pressure in the vacuum chamber of 150 Pa and atmospheric pressure, the moving speed of 20.0 mm / second, the peripheral speed of 78.5 mm / second, and the distance between the non-contact roll and the substrate of 0.5 mm. Comparative resin-filled substrates 1 to 7 were obtained in the same manner as in Example 1 except that the contents were changed. The moving speed (i) and the peripheral speed (v) are the same values as shown in Table 6.

<Comparative Example 8-19>
Using the screen printing device {Screen printing device “SSA-PC660” manufactured by Tokai Seiki Co., Ltd.}, the squeegee moving speed 20 mm / sec, squeegee printing pressure 3 MPa, squeegee angle 15 degrees, and the thicknesses (turn height t) The paste was filled by screen printing through a metal mask plate having openings with a minimum width (corresponding to the pattern width d) to obtain comparative resin-filled substrates 8 to 19.
The accuracy and the number of voids evaluated in the same manner as in Example 1 are shown in Table 7.

  The pattern forming method of the present invention was remarkably superior in pattern accuracy and the number of voids as compared with the comparative example.

The pattern formation method of the present invention can be used for pattern formation of circuit boards and displays. In addition, it can be used for a method of forming a pattern on a plate-like surface made of metal, glass, plastic or the like.

It is sectional drawing which showed typically an example of the front-end | tip shape of the front-end | tip of a doctor. It is sectional drawing which showed typically an example of the front-end | tip shape of the front-end | tip of a doctor. It is sectional drawing which showed typically the component of an upper cone type disk and a lower plane disk among the viscoelasticity measuring apparatuses for measuring a storage elastic modulus (G '). In an Example, it is the vertical sectional view which showed typically the state at the time of the start of a filling process (2) among the aspects which apply the pattern formation method of this invention. In an Example, it is the vertical sectional view which showed typically the state in the filling process of a filling process (2) among the aspects which apply the pattern formation method of this invention. In an Example, it is the vertical sectional view which showed typically the state at the time of completion | finish of a filling process (2) among the modes which apply the pattern formation method of this invention. It is the vertical sectional view which showed typically signs that a pattern was formed in each process of an example. It is the perspective view which showed typically the pattern formation board obtained in the Example. It is the perspective view which showed the guard (14) typically. It is a perspective view which shows notionally the positional relationship of a doctor (6), a non-contact roll (7), and a guard (14).

Explanation of symbols

1. Upper cone disk 1. Lower flat disk 2. Vacuum chamber 4. Substrate fixing base 5. Substrate 6. Doctor 7. Non-contact roll (R)
8). Paste (P)
9. 10. Rotating shaft of non-contact roll (R) Photosensitive resin layer 11. 11. Concavities formed in the photosensitive resin layer Photomask 13. Pattern 14 guard

Claims (8)

A step (1) of providing a photosensitive resin layer on the substrate surface, and then exposing and developing to form a recess on the substrate surface;
(R) rotation while the non-contact roll (R) is linearly moved at a moving speed (i) (mm / sec) in a direction horizontal to the substrate surface and in a direction perpendicular to the rotation axis of (R). (R) is rotated at a peripheral speed (v) (mm / second) larger than the moving speed (i) so that the rotating direction of the portion on the substrate side from the axis is opposite to the moving direction, and 10 to 10,000 Pa Filling the paste (P) into the recesses provided on the substrate surface under pressure (2 1 ),
A step (22) carried out after the step (21) and filled with a paste (P) in a recess provided on the substrate surface under atmospheric pressure;
And the step of curing the filled paste (P) (3)
A pattern forming method comprising: The pattern forming method according to claim 1, wherein the moving speed (i) and the peripheral speed (v) are in a relationship represented by Formula 1.

{(I) × 10} ≧ (v) ≧ {(i) × (1.2 + 0.1 × t / d)} (1)

t is The pattern height (mm) to be formed and d represents the minimum pattern width (mm) to be formed. The pattern formation method according to claim 1 or 2, wherein the shortest distance between the photosensitive resin layer and the non-contact roll (R) is 0.1 to 5 mm. The pattern formation method in any one of Claims 1-3 including the process (4) which removes photosensitive resin after a process (3), or including a baking process (34) in a process (3). The pattern formation method according to claim 1, wherein the storage elastic modulus (G ′) of the paste (P) is 10 to 10,000 Pa. A circuit board manufacturing method using the pattern forming method according to claim 1. A method for manufacturing a display panel, wherein the pattern forming method according to claim 1 is used. The electronic device which incorporates the circuit board and / or display panel which were manufactured using the pattern formation method in any one of Claims 1-5.