JP2016152410A - Method of manufacturing electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing an electronic component that can form a resist cured body layer with a high reflective index to light by using white pigment and also enhance resolution, undercut preventiveness and migration resistance of the resist cured body layer.SOLUTION: A method of manufacturing an electronic component according to the present invention comprises: a first step of using a non-development type photocurable composition which includes a photocurable compound, a photopolymerization initiator, and white pigment, can be cured by irradiation with light, and can form a resist cured body layer so as to form a plurality of resist layers in a patterned state on a surface of an electronic component body without exposure; and a second step of curing the plurality of resist layers by irradiating the plurality of resist layers with light so as to form a plurality of resist cured body layers.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a non-developable light that contains a photocurable compound, a photopolymerization initiator, and a white pigment, can be cured by light irradiation, and can form a cured resist layer without development. The present invention relates to a method for producing an electronic component using a curable composition.

  A solder resist film is widely used as a protective film for protecting a printed wiring board from high-temperature solder.

  In various electronic components, a light emitting diode (hereinafter abbreviated as LED) chip is mounted on the upper surface of a printed wiring board. A white solder resist film may be formed on the upper surface of the printed wiring board in order to use light that has reached the upper surface side of the printed wiring board among the light emitted from the LEDs. In this case, not only light directly irradiated from the surface of the LED chip to the opposite side of the printed wiring board but also reflected light that reaches the upper surface side of the printed wiring board and is reflected by the white solder resist film can be used. . Therefore, the utilization efficiency of the light generated from the LED can be increased.

  In the following Patent Document 1, a white solder resist A is applied and cured on a substrate on which electronic circuit wiring is formed, and a white solder resist B is further applied and cured on the white solder resist A. A method of manufacturing a printed wiring board including a process is disclosed. This printed wiring board has a reflector function of a backlight.

JP 2011-66267 A

  Patent Document 1 merely describes the use of a developing type photosensitive composition or a thermosetting resin composition in order to form the white solder resists A and B.

  In the development type photosensitive composition, in order to form a resist film, many steps such as an exposure step and a development step in photolithography are required. For this reason, there are many processes and the manufacturing efficiency of a printed wiring board is bad.

  Furthermore, since the development type photosensitive composition performs development using a chemical solution such as acid or alkali, the environmental load is large. Furthermore, an extra resist material must be used to form a resist film portion that is removed by development. The resist film portion removed by development becomes waste. For this reason, since the amount of waste is large, the environmental load is large.

  In addition, when a development type photosensitive composition or a thermosetting resin composition (epoxy thermosetting resin, silicone thermosetting resin, etc.) as described in Patent Document 1 is used, the resolution of the resist film is low. It may be low, or a recess may be formed on the outer peripheral surface of the resist film, resulting in undercutting or migration.

  Further, the white resist film is required to have a high light reflectance. However, conventionally, there is a problem that it is difficult to improve all of resolution, undercut prevention and migration resistance, particularly in a resist film containing a white pigment.

  An object of the present invention is to use a white pigment to form a resist cured product layer having a high light reflectance, and further to improve the resolution, undercut prevention and migration resistance of the resist cured product layer. An object of the present invention is to provide an electronic component manufacturing method that can be enhanced.

  According to a wide aspect of the present invention, it contains a photocurable compound, a photopolymerization initiator, and a white pigment, can be cured by light irradiation, and can form a cured resist layer without development. A first step of forming a plurality of resist layers in a pattern on the surface of the electronic component body using a non-developable photocurable composition without developing, and the plurality of resist layers And a second step of curing the plurality of resist layers to form a plurality of resist cured product layers, and a method for manufacturing an electronic component.

  On the specific situation with the manufacturing method of the electronic component which concerns on this invention, content of the said white pigment in the said non-developing type photocurable composition is 10 to 80 weight%.

  On the specific situation with the manufacturing method of the electronic component which concerns on this invention, the said non-development type photocurable composition contains the thiol group containing compound which has 1 or more of thiol groups.

  On the specific situation with the manufacturing method of the electronic component which concerns on this invention, the total thickness of the said several resist hardened | cured material layer is 20 micrometers or more and 90 micrometers or less.

  On the specific situation with the manufacturing method of the electronic component which concerns on this invention, the average thickness per layer of the said several resist hardened | cured material layer is 5 micrometers or more and 40 micrometers or less.

  In a specific aspect of the method for manufacturing an electronic component according to the present invention, the plurality of resist layers are formed by screen printing.

  In a specific aspect of the method for manufacturing an electronic component according to the present invention, three or more resist layers are formed as the plurality of resist layers, and three or more resist cured product layers are formed as the plurality of resist cured product layers. A cured resist layer is formed.

  In a specific aspect of the method for manufacturing an electronic component according to the present invention, after forming a part of the resist layer of the plurality of resist layers, the part of the resist layer is irradiated with light, and the part of the resist layer is irradiated with light. The resist layer is cured to form a part of the cured resist layer, and after forming another resist layer of the plurality of resist layers, the other resist layer is irradiated with light. Then, the other resist layer is cured to form a plurality of resist cured product layers including the part of the resist cured product layer and the other resist cured product layer.

  In a specific aspect of the method for manufacturing an electronic component according to the present invention, after all the resist layers of the plurality of resist layers are formed, the entire resist layer is irradiated with light, and the entire resist layer is cured. In this way, a plurality of resist cured product layers are formed.

  In a specific aspect of the method for manufacturing an electronic component according to the present invention, the first step includes, as the non-developable photocurable composition, a photocurable compound, a photopolymerization initiator, and a white pigment. Including a first composition which can be cured by light irradiation and can form a cured resist layer without development, and is patterned on the surface of the electronic component body without development. In addition, a step of forming a first resist layer as one layer of the plurality of resist layers, a photocurable compound, a photopolymerization initiator, and a white pigment as the non-developable photocurable composition A second resist composition that can be cured by irradiation with light and can form a cured resist layer without development, and the electronic component main body side of the first resist layer. On the opposite surface, the multiple layers in a pattern without development Forming a second resist layer as one layer of the resist layer, wherein the second step irradiates the first resist layer with light and cures the first resist layer; A step of forming a first resist cured product layer as one layer of the plurality of resist cured product layers, irradiating light to the second resist layer, curing the second resist layer, Forming a second resist cured product layer as one layer of the plurality of resist cured product layers.

  In a specific aspect of the method for manufacturing an electronic component according to the present invention, the first step includes, as the non-developable photocurable composition, a photocurable compound, a photopolymerization initiator, and a white pigment. And the first resist layer side of the second resist layer using a third composition that can be cured by irradiation with light and can form a cured resist layer without development. Includes a step of forming a third resist layer as a layer of the plurality of resist layers on the opposite surface in a pattern without development, and the second step includes the third step. The method includes irradiating the resist layer with light to cure the third resist layer to form a third resist cured product layer as one layer of the plurality of resist cured product layers.

  In the method for manufacturing an electronic component according to the present invention, a photocurable compound, a photopolymerization initiator, and a white pigment are included, and can be cured by light irradiation, and a cured resist layer is formed without development. Since a non-developable photocurable composition that can be used is used, it is not necessary to perform many steps such as an exposure step and a development step.

  Furthermore, in the method for manufacturing an electronic component according to the present invention, a resist cured product layer having a high light reflectance can be formed by using a white pigment.

  Furthermore, in the method for manufacturing an electronic component according to the present invention, a plurality of resist layers are formed in a pattern on the surface of the electronic component body using the non-developable photocurable composition without performing development. And a second step of irradiating the plurality of resist layers with light and curing the plurality of resist layers to form a plurality of resist cured product layers. Even if a pigment is used, the resolution, undercut prevention and migration resistance of the resist cured product layer can all be improved.

1A to 1E are cross-sectional views for explaining a method of manufacturing an electronic component according to an embodiment of the present invention. 2A to 2D are cross-sectional views for explaining a method of manufacturing an electronic component according to another embodiment of the present invention. 3A to 3C are cross-sectional views for explaining a method of manufacturing an electronic component according to another embodiment of the present invention. 4A to 4E are cross-sectional views for explaining an example of a method for producing an electronic component using a conventional developing resist composition.

  Details of the present invention will be described below.

(Method for manufacturing electronic parts)
In the method for manufacturing an electronic component according to the present invention, a non-developable photocurable composition is used. The non-developable photocurable composition includes a photocurable compound, a photopolymerization initiator, and a white pigment. Since the non-developable photocurable composition contains a photocurable compound and a photopolymerization initiator, it can be cured by light irradiation. The non-developable photocurable composition can form a cured resist layer without development.

  In the method for producing an electronic component according to the present invention, the non-developable photocurable composition is not used after being developed. Since development is not performed to form a resist film, the non-developable photocurable composition is different from a developable composition that develops to form a resist cured product layer (resist film). In the method for manufacturing an electronic component according to the present invention, a composition capable of obtaining a cured resist layer can be adopted as the non-developable photocurable composition without performing development.

  By using the non-developable photocurable composition, a good resist cured product layer can be formed without performing many steps such as an exposure step and a development step in photolithography. In the electronic component manufacturing method according to the present invention, it is not necessary to perform many steps such as an exposure step and a development step. For this reason, the amount of waste can be reduced and the environmental load can be reduced. Furthermore, the manufacturing cost of the electronic component can be reduced.

  In the method for manufacturing an electronic component according to the present invention, a white pigment is used in the non-developable photocurable composition, whereby a resist cured product layer having a high light reflectance can be formed.

  The method for manufacturing an electronic component according to the present invention includes forming a plurality of resist layers in a pattern on the surface of the electronic component body using the non-developable photocurable composition without performing development. And a second step of forming a plurality of cured resist layers by irradiating the plurality of resist layers with light and curing the plurality of resist layers. In the first step, development is not performed to form a patterned resist layer. After the first step, the entire second step may be performed. A part of the second step may be performed during the first step.

  In the method for manufacturing an electronic component according to the present invention, a development type composition is not used, and a thermosetting composition different from a photocurable composition is not used. In the method for manufacturing an electronic component according to the present invention, a multilayer resist cured product layer is formed without performing development. Therefore, even if a white pigment is used, the resolution of the resist cured product layer, the undercut prevention property, and the resistance to resistance. All migration can be improved.

  Specifically, the patterned resist cured product layer can be formed at a predetermined position with high accuracy. For example, a patterned resist cured product layer can be selectively and accurately formed in a region where no electrode is present. For this reason, the resolution is increased and the reliability of the electronic component is increased.

  Furthermore, it becomes difficult to form a recess recessed inward on the outer peripheral surface below the cured resist layer. For this reason, undercut prevention property becomes high and the reliability of an electronic component becomes high.

  Furthermore, migration resistance is also increased, insulation failure is unlikely to occur in the electronic component, and the reliability of the electronic component is increased.

  Moreover, the thickness of a resist cured material layer can be thickened by forming the resist cured material layer of multiple layers. For this reason, resist performance appears even higher.

  Hereinafter, a specific method for manufacturing an electronic component of the present invention will be described with reference to the drawings.

  1A to 1E are cross-sectional views for explaining a method of manufacturing an electronic component according to an embodiment of the present invention.

  First, it contains a photocurable compound, a photopolymerization initiator, and a white pigment, can be cured by irradiation with light, and can form a resist cured product layer without development. Prepare a composition. In the present embodiment, the non-developable photocurable composition contains a photocurable compound, a photopolymerization initiator, and a white pigment, can be cured by light irradiation, and can be resisted without development. A first composition capable of forming a cured product layer, a photocurable compound, a photopolymerization initiator, and a white pigment, which can be cured by light irradiation and is cured without development. A cured resist product that includes a second composition capable of forming a physical layer, a photocurable compound, a photopolymerization initiator, and a white pigment, is curable by light irradiation, and is not developed. And a third composition capable of forming a layer. The first composition, the second composition, and the third composition may be the same or different. Further, in order to enhance the adhesion between the substrate and the first resist layer, a resist layer having a titanium oxide content of less than 10% by weight is provided as an adhesion layer between the substrate and the first resist layer. It may be formed.

  Furthermore, as shown in FIG. 1A, an electronic component main body 11 is prepared. A substrate 11A is used as the electronic component body 11, and a plurality of electrodes 11B are disposed on the surface of the substrate 11A. In the region where the electrode 11B is not provided on the substrate 11A, the surface of the portion where the multiple layers of the cured resist layer 2 are formed later may be an insulating layer or the like.

  Next, as shown in FIG.1 (b), the said 1st composition (non-development type photocurable composition) is apply | coated on the surface of the electronic component main body 11, and the multiple resist layers 12 ( A first resist layer 12A is formed as one layer shown in FIG. In FIG. 1B, the first resist layer 12A is formed in a pattern on the surface of the electronic component body 11 without performing development.

  Next, as shown in FIG. 1C, on the surface of the electronic component main body 11, more specifically, on the surface opposite to the electronic component main body 11 side of the first resist layer 12A, The second resist layer 12B is formed as a single layer of the plurality of resist layers 12 (see FIG. 1D) by applying the above composition (non-developable photocurable composition). In FIG. 1C, the second resist layer 12B is formed in a pattern on the surface of the electronic component body 11 without performing development. A second resist layer 12B is formed on the entire surface of the first resist layer 12A.

  Next, as shown in FIG. 1 (d), on the surface of the electronic component main body 11, more specifically, on the surface opposite to the first resist layer 12A side of the second resist layer 12B, A third composition (non-developable photocurable composition) is applied to form a third resist layer 12C as one layer of the plurality of resist layers 12. In FIG. 1D, the third resist layer 12C is formed in a pattern on the surface of the electronic component body 11 without performing development. A third resist layer 12C is formed on the entire surface of the second resist layer 12B.

  As a result, a plurality of resist layers 12 including the first resist layer 12A, the second resist layer 12B, and the third resist layer 12C are formed on the surface of the electronic component body 21. In the present embodiment, the resist layer 12 has three layers. Note that the third resist layer 12C may not be formed. There may be two resist layers. A fourth resist layer, a fifth resist layer,..., An nth resist layer (n is an arbitrary integer) may be further formed.

  The plurality of resist layers 12 are partially formed at a plurality of locations. Specifically, a plurality of resist layers 12 are formed between the plurality of electrodes 11B on the surface of the substrate 11A. The multiple resist layers 12 are resist patterns. For example, the plurality of resist layers 12 are formed only at positions corresponding to resist layer portions that are formed to remain after development, assuming that a conventional developing composition is used. The resist layer 12 is not formed at a position corresponding to a resist layer portion to be removed by development using a conventional developing composition.

  Examples of the coating method of the non-developable photocurable composition include a coating method using a dispenser, a coating method using screen printing, and a coating method using an inkjet apparatus. Screen printing is preferred because of its excellent manufacturing efficiency. It is preferable to pattern-print the non-developable photocurable composition. It is preferable to form a plurality of resist layers by screen printing. A plurality of resist layers can be formed by performing screen printing a plurality of times.

  Next, the plurality of resist layers 12 are irradiated with light. For example, the resist layer 12 is irradiated with light from the side opposite to the electronic component main body 11 side of the plurality of resist layers 12. As a result, as shown in FIG. 1E, the plurality of resist layers 12 are photocured, and a plurality of resist cured product layers 2 are formed. Specifically, the first resist layer 12A is irradiated with light from the side opposite to the electronic component main body 11 side of the first resist layer 12A. As a result, the first resist cured product layer 2 </ b> A is formed as one layer of the plurality of resist cured product layers 2. The second resist layer 12B is irradiated with light from the side opposite to the electronic component body 11 side of the second resist layer 12B and from the side of the second resist layer 12B opposite to the first resist layer 12A side. . As a result, the second resist cured product layer 2 </ b> B is formed as one layer of the plurality of resist cured product layers 2. The third resist layer 12C is irradiated with light from the side opposite to the electronic component main body 11 side of the third resist layer 12C and from the side opposite to the second resist layer 12B side of the third resist layer 12C. . As a result, a third resist cured product layer 2 </ b> C is formed as one layer of the plurality of resist cured product layers 2. As a result, the electronic component 1 in which a plurality of resist cured product layers 2 are formed on the surface of the electronic component main body 11 (electronic component main body) is obtained.

  During the light irradiation, the first resist layer 12A is irradiated with light, the second resist layer 12B is irradiated with light, and the third resist layer 12C is irradiated with light. The first resist layer 12A may be irradiated with light before the formation of the second resist layer 12B, after the formation of the second resist layer 12B, or from the third resist layer 12C. It may be before formation or after formation of the third resist layer 12C. The light irradiation to the second resist layer 12B may be before the formation of the third resist layer 12C or after the formation of the third resist layer 12C. From the viewpoint of increasing the production efficiency, it is preferable to irradiate the plurality of resist layers 12 with light. On the other hand, through each step of FIG. 2 (a), FIG. 2 (b), FIG. 2 (c), FIG. 2 (d), FIG. 3 (a), FIG. 3 (b), and FIG. It is also preferable to obtain an electronic component.

  After forming all the resist layers of the plurality of resist layers, the resist layers may be irradiated with light to cure all the resist layers to form a plurality of resist cured product layers. (See FIGS. 1A to 1E). In this case, the production efficiency of the cured resist layer is increased. Further, in this forming method, one step including the formation of the resist layer and the curing of the resist layer is performed once.

  After forming a part of the plurality of resist layers, the part of the resist layer is irradiated with light, and the part of the resist layer is cured to form a part of the resist cured product layer. And then forming another resist layer of the plurality of resist layers, irradiating the other resist layer with light, curing the other resist layer, and A plurality of resist cured product layers including a cured product layer and another resist cured product layer may be formed (see FIGS. 2A to 2D and FIGS. 3A to 3C). In this case, each resist cured product layer can be sufficiently cured, particularly the lower resist cured product layer can be sufficiently cured, and an excellent resolution can be obtained. Further, in this forming method, one step including the formation of the resist layer and the curing of the resist layer may be performed a plurality of times, twice, or three times or more. In order to increase the production efficiency, the exposure amount when irradiating light to the part of the resist layer may be reduced. Also in this case, since the light is irradiated a plurality of times, each cured resist layer can be sufficiently cured.

  In addition, the manufacturing method of the resist cured material layer demonstrated using FIG. 1 (a)-(e), FIG. 2 (a)-(d), and FIG. 3 (a)-(c) is the range of this invention. It can be changed as appropriate. However, development is not performed in order to form a resist layer and a resist hardened material layer at the time of manufacture of an electronic component.

  Conventionally, development type compositions have often been used. When using a negative developing composition, as shown in FIG. 4A, for example, an electronic component body 111 having a substrate 111A and an electrode 111B arranged on the surface of the substrate 111A is prepared. . Next, as shown in FIG. 4B, a resist layer 112 is formed on the entire surface of the electronic component main body 111. Next, as shown in FIG. 4C, only the resist layer 112 on the electrode 111B is irradiated with light through a mask 113. Thereafter, as shown in FIG. 4D, development is performed, and the resist layer 112 located on the electrode 111B is partially removed. After the resist layer 112 is partially removed, the remaining resist layer 112 is thermally cured. As a result, as shown in FIG. 4E, an electronic component 101 having a cured resist layer 102 formed on the surface of the electronic component main body 111 (electronic component main body) is obtained.

  Thus, when using a development type composition, the formation efficiency of a resist hardened material layer and the manufacture efficiency of electronic parts are bad. Furthermore, it is necessary to perform development. Further, the resolution of the resist cured product layer may be low, undercut may occur, or migration may occur.

  On the other hand, by employing the method for manufacturing an electronic component according to the present invention, it is possible to increase the formation efficiency of the cured resist layer and the manufacturing efficiency of the electronic component. Further, there is no need to perform development. Furthermore, even if a white pigment is used, the resolution, undercut prevention and migration resistance of the resist cured product layer can all be improved.

  From the viewpoint of preventing thermal deterioration of the electronic component body, it is preferable that the resist layer is not thermally cured by the action of a thermosetting agent in order to form the resist cured product layer.

  In order to form the said resist hardened | cured material layer, it is preferable that a roughening process is not performed.

  The electronic component is preferably a printed wiring board.

  The non-developable photocurable composition contains (A) a photocurable compound, (D) a white pigment, and (E) a photopolymerization initiator. The non-developable photocurable composition comprises (A) a photocurable compound, (B) a reactive diluent having at least one ethylenically unsaturated bond, and (C) a thiol having at least one thiol group. It preferably contains a group-containing compound, (D) a white pigment, and (E) a photopolymerization initiator. The photocurable composition according to the present invention preferably contains no (F) thermosetting compound or contains (F) a thermosetting compound in an amount of 5% by weight or less.

  In the non-developable photocurable composition having the above preferred composition, the adhesion of the resist cured product layer to the electronic component can be enhanced without development. For example, the adhesion between the electronic component main body such as a substrate and the resist cured product layer can be enhanced, and peeling of the resist cured product layer can be suppressed. Further, since the non-developable photocurable composition contains (D) a white pigment, a white resist cured product layer can be formed, and a resist film having a high light reflectance can be obtained. When the resist cured product layer is white, the light reflectance of the resist cured product layer can be increased. Furthermore, with the non-developable photocurable composition having the above preferred composition, it is possible to obtain a resist cured product layer that hardly undergoes peeling and discoloration even when exposed to high temperatures. For this reason, reliability of an electronic component etc. provided with a resist hardened material layer can be improved.

  In order to harden the said photocurable composition by irradiation of light, it does not need to contain the (F) thermosetting compound and may not contain the thermosetting agent. It is preferable that the photocurable composition is not used after being thermoset by the action of a thermosetting agent. In order to form the resist film, the resist layer disposed on the surface of the electronic component main body may not be thermally cured. In order to form the resist, it is not necessary to heat the resist layer disposed on the surface of the electronic component body. However, the resist layer may be heated at a low temperature. In order to form the resist film, the resist layer is preferably not heated to 280 ° C. or higher, more preferably not heated to 180 ° C. or higher, and still more preferably not heated to 60 ° C. or higher. The lower the temperature at which the resist layer is heated, the more the thermal deterioration of the electronic component body can be suppressed.

  From the viewpoint of effectively increasing the resolution, undercut prevention and migration resistance of the resist cured product layer, the total thickness of the plurality of resist cured product layers is preferably 20 μm or more, more preferably 30 μm or more, preferably 90 μm. Below, more preferably 60 μm or less. The total thickness of the plurality of resist cured product layers is the thickness of the three resist cured product layers in the case of forming three resist cured product layers. The total thickness of the plurality of resist cured product layers is the thickness of the two resist cured product layers when two resist cured product layers are formed.

  From the viewpoint of effectively improving the resolution, undercut prevention and migration resistance of the resist cured product layer, the average thickness per layer of the plurality of resist cured product layers is preferably 5 μm or more, more preferably 10 μm or more, Preferably it is 40 micrometers or less, More preferably, it is 30 micrometers or less. The average thickness of each of the first resist cured product layer, the second resist cured product layer, and the third resist cured product layer is preferably 5 μm or more, more preferably 10 μm or more, preferably 40 μm. Hereinafter, it is more preferably 30 μm or less.

  Hereinafter, each component contained in the photocurable composition will be described.

((A) photocurable compound)
Since the non-developable photocurable composition is not used for development, the (A) photocurable compound preferably does not have a carboxyl group. Since it is excellent in photocurability, it is preferable that (A) the photocurable composition is (A1) a photocurable compound having two or more ethylenically unsaturated bonds. (A1) By using the photocurable compound, the adhesion of the resist cured product layer to the electronic component main body is effectively increased. In particular, when the content of the (D) white pigment is large, if the (A1) photocurable compound is not used, the adhesion of the resist cured product layer tends to be lowered. (A1) By using a photocurable compound, even if there is much content of (D) white pigment, the adhesiveness of a resist hardened | cured material layer can be improved. Moreover, it is preferable that (A) a photocurable compound does not have a carboxyl group. (A) Since a photocurable compound does not have a carboxyl group, the bad influence by the carboxyl group in a resist cured material layer can be prevented, for example, discoloration of a resist cured material layer can be suppressed. (A) As for a photocurable compound, only 1 type may be used and 2 or more types may be used together.

  (A1) Examples of the group containing an ethylenically unsaturated bond in the photocurable compound include a vinyl group, an allyl group, and a (meth) acryloyl group. A (meth) acryloyl group is preferable from the viewpoint of effectively allowing the reaction to proceed and further suppressing peeling and discoloration. (A) It is preferable that a photocurable compound has a (meth) acryloyl group.

  From the viewpoint of enhancing the adhesion of the cured resist layer to the electronic component body, the (A) photocurable compound is preferably (A11) epoxy (meth) acrylate. From the viewpoint of increasing the hardness of the resist cured product layer, the (A11) epoxy (meth) acrylate preferably contains a bifunctional epoxy (meth) acrylate and a trifunctional or higher functional epoxy (meth) acrylate. The bifunctional epoxy (meth) acrylate preferably has two (meth) acryloyl groups. The tri- or higher functional epoxy (meth) acrylate preferably has three or more (meth) acryloyl groups.

  (A11) Epoxy (meth) acrylate is obtained by reacting (meth) acrylic acid with an epoxy compound. (A11) Epoxy (meth) acrylate can be obtained by converting an epoxy group into a (meth) acryloyl group. Since the said photocurable composition is hardened | cured by irradiation of light, it is preferable that (A11) epoxy (meth) acrylate does not have an epoxy group.

  (A11) As epoxy (meth) acrylate, bisphenol type epoxy (meth) acrylate (for example, bisphenol A type epoxy (meth) acrylate, bisphenol F type epoxy (meth) acrylate, bisphenol S type epoxy (meth) acrylate), cresol Novolak type epoxy (meth) acrylate, amine modified bisphenol type epoxy (meth) acrylate, caprolactone modified bisphenol type epoxy (meth) acrylate, carboxylic anhydride modified epoxy (meth) acrylate, phenol novolac type epoxy (meth) acrylate, etc. Can be mentioned.

  Examples of commercially available bifunctional epoxy (meth) acrylates include KAYARAD R-381 (Nippon Kayaku Co., Ltd., bisphenol A type epoxy acrylate), Daicel Ornex Co., Ltd. EBECRYL 3701 and EBECRYL 3708 (modified bisphenol A type epoxy acrylate), etc. Is mentioned. Moreover, EBECRYL3603 (the Daicel Ornex company make, novolak epoxy acrylate) etc. are mentioned as a commercial item of the epoxy (meth) acrylate more than trifunctional. Further, a trifunctional or higher functional epoxy (meth) acrylate may be obtained by modifying a hydroxyl group of a bifunctional epoxy (meth) acrylate and introducing a (meth) acryloyl group.

  “(Meth) acryloyl group” refers to an acryloyl group and a methacryloyl group. “(Meth) acryl” refers to acrylic and methacrylic. “(Meth) acrylate” refers to acrylate and methacrylate.

  (A) It is preferable that the weight average molecular weight of a photocurable compound is 2000 or more. (A) The adhesiveness of a resist hardened | cured material layer becomes it high that the weight average molecular weight of a photocurable compound is 2000 or more. (A) The weight average molecular weight of a photocurable compound becomes like this. Preferably it is 20000 or less.

  The weight average molecular weight in (A) a photocurable compound and (B) a reactive diluent is a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC), and the measurement apparatus and measurement conditions described below. Can be measured.

Measuring device: “Waters GPC System (Waters 2690 + Waters 2414 (RI))” manufactured by Nihon Waters
Measurement condition columns: Shodex GPC LF-G × 1, Shodex GPC LF-804 × 2 Mobile phase: THF 1.0 mL / min Sample concentration: 5 mg / mL
Detector: Differential refractive index detector (RID)
Standard substance: polystyrene (Made by TOSOH, molecular weight: 620 to 590000)

  From the viewpoint of effectively suppressing peeling and discoloration, the (A) photocurable compound is preferably not a compound having an alicyclic skeleton, and preferably not an epoxy (meth) acrylate having an alicyclic skeleton. . From the viewpoint of further suppressing peeling and discoloration, the (A) photocurable compound preferably contains a compound having an aromatic skeleton, and preferably contains an epoxy (meth) acrylate having an aromatic skeleton.

  From the viewpoint of effectively suppressing peeling and discoloration, the (A) photocurable compound is preferably an epoxy (meth) acrylate, urethane (meth) acrylate or polyester (meth) acrylate having an aromatic skeleton. More preferably, it is an epoxy (meth) acrylate or a urethane (meth) acrylate having a group skeleton.

  (A11) The epoxy (meth) acrylate may be an epoxy (meth) acrylate obtained by modifying a hydroxyl group of an epoxy (meth) acrylate having a hydroxyl group. In this case, the degree of crosslinking can be increased and the hardness can be increased. Examples of the compound that can be used for modification include a silane coupling agent and a monomer having an isocyanate group. Examples of the silane coupling agent include compounds having a functional group such as vinyl group, (meth) acryloyl group, styryl group, mercapto group, epoxy group, amino group, sulfide group, ureido group, and isocyanate group. A compound having a vinyl group, a (meth) acryloyl group, a styryl group, or a mercapto group is preferred because of photoreactivity. Examples of the monomer having an isocyanate group include a compound having a vinyl group, a (meth) acryloyl group, a styryl group, or a mercapto group.

  The content of (A) the photocurable compound, (A1) the photocurable compound, and (A11) the epoxy (meth) acrylate is preferably 5% by weight or more, more preferably 10%, in 100% by weight of the photocurable composition. % By weight or more, preferably 40% by weight or less, more preferably 30% by weight or less. When the contents of (A) the photocurable compound, (A1) the photocurable compound, and (A11) the epoxy (meth) acrylate are not less than the above lower limit and not more than the above upper limit, the adhesion of the resist cured product layer is effectively improved. Get higher. In addition, from the viewpoint of effectively increasing the adhesion of the resist cured product layer, in 100% by weight of the photocurable composition, a bifunctional epoxy (meth) acrylate having a weight average molecular weight of 2000 or more and a weight average molecular weight are The total content with the trifunctional or higher functional epoxy (meth) acrylate that is 2000 or higher is preferably 5% by weight or higher, more preferably 10% by weight or higher, preferably 40% by weight or lower, more preferably 30% by weight or lower. It is.

((B) Reactive diluent having one or more ethylenically unsaturated bonds)
(B) The reactive diluent has one or more ethylenically unsaturated bonds. (A) By using the reactive diluent (B) together with the photocurable compound, (D) even if the content of the white pigment is large, the adhesion of the resist cured product layer can be effectively increased. It is easy to control the viscosity of the photocurable composition within an optimal range. (B) The reactive diluent is a compound different from (A) the photocurable compound. (B) It is preferable that a reactive diluent does not have a carboxyl group. (B) The weight average molecular weight of the reactive diluent is preferably less than 2000. (B) The weight average molecular weight of the reactive diluent is generally less than 2000, preferably 800 or less, more preferably 600 or less. (B) Only 1 type of reactive diluent may be used and 2 or more types may be used together.

  (B) Examples of the group containing an ethylenically unsaturated bond in the reactive diluent include a vinyl group, an allyl group, and a (meth) acryloyl group. A (meth) acryloyl group is preferable from the viewpoint of effectively allowing the reaction to proceed and further suppressing peeling and discoloration. (B) The reactive diluent preferably has a (meth) acryloyl group.

  (B) The reactive diluent is not particularly limited, and is a polyhydric alcohol (meth) acrylic acid adduct, a polyhydric alcohol alkylene oxide-modified (meth) acrylic acid adduct, urethane (meth) acrylates. And polyester (meth) acrylates. Examples of the polyhydric alcohol include diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, trimethylol propane, cyclohexane dimethanol, tricyclodecane dimethanol, an alkylene oxide adduct of bisphenol A, and Examples include pentaerythritol.

  (B) The reactive diluent may be (B1) a compound having one ethylenically unsaturated bond. From the viewpoint of further improving the adhesion of the resist cured product layer, the (B) reactive diluent preferably contains (B1) a compound having one ethylenically unsaturated bond, and (meth) acryloyl group is 1 It is preferable that the compound which has one is included.

  (B) The reactive diluent may contain a compound having two ethylenically unsaturated bonds, and (B2) may contain a compound having two or more ethylenically unsaturated bonds. From the viewpoint of further improving the adhesion of the cured resist layer, the (B) reactive diluent preferably contains (B2) a compound having two or more ethylenically unsaturated bonds, and has a (meth) acryloyl group. It is preferable that the compound which has 2 or more is included.

  From the viewpoint of further improving the adhesion of the resist cured product layer, the (B) reactive diluent preferably contains an alicyclic compound, or contains an aromatic ring or a hydroxyl group. (B) The reactive diluent is preferably a monofunctional compound, but may contain a plurality of components of a polyfunctional compound such as a bifunctional compound.

  The content of (B) a reactive diluent and (B2) a compound having two or more ethylenically unsaturated bonds in 100% by weight of the photocurable composition is preferably 5% by weight or more, more preferably 10% by weight. As mentioned above, Preferably it is 50 weight% or less, More preferably, it is 40 weight% or less. When the content of the (B) reactive diluent and (B2) the compound having two or more ethylenically unsaturated bonds is not less than the above lower limit and not more than the above upper limit, the adhesion of the resist cured product layer is effectively enhanced. .

((C) a thiol group-containing compound having one or more thiol groups)
(C) By using a thiol group-containing compound having at least one thiol group, a resist cured product layer that can be hardly peeled off even when exposed to high temperatures and has a high heat resistance can be obtained. Can be obtained. (C) As for a thiol group containing compound, only 1 type may be used and 2 or more types may be used together.

  (C) Specific examples of the thiol group-containing compound include trimethylolpropane tris (3-mercaptopropionate) (TMMP), pentaerythritol tetrakis (3-mercaptopropionate) (PEMP) manufactured by SC Organic Chemical Co., Ltd. Tris-[(3-mercaptopropionyloxy) -ethyl] -isocyanurate (TEMPIC), tetraethylene glycol bis (3-mercaptopropionate) (EGMP-4), dipentaerythritol hexakis (3-mercaptopropionate) ) (DPMP) and other primary polyfunctional thiols, pentaerythritol tetrakis (3-mercaptobutyrate) (Karenz MT PE1), 1,3,5-tris (3-mercaptobutyryloxyethyl)- 1,3,5-triazine-2, , 6 (1H, 3H, 5H) -trione (Karenz MT NR1), secondary polyfunctional thiol such as 1,4-bis (3-mercaptobutyryloxy) butane (Karenz MT BD1), manufactured by SC Organic Chemical Co., Ltd. (Β-mercaptopropionic acid (BMPA), methyl-3-mercaptopropionate (MPM), 2-ethylhexyl-3-mercaptopropionate (EHMP), n-octyl-3-mercaptopropionate (NOMP), And monofunctional thiols such as methoxybutyl-3-mercaptopropionate (MBMP) and stearyl-3-mercaptopropionate (STMP).

  In 100% by weight of the photocurable composition, the content of the (C) thiol group-containing compound is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, preferably 10% by weight or less, more preferably Is 5% by weight or less. (C) When the content of the thiol group-containing compound is not less than the above lower limit and not more than the above upper limit, peeling and discoloration in the resist cured product layer are further suppressed. Further, when the content of the (C) thiol group-containing compound is not more than the above upper limit, gelation hardly proceeds during storage. (C) Curability becomes still higher that content of a thiol group containing compound is more than the above-mentioned minimum.

  (A) The content of the (C) thiol group-containing compound is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more, preferably less than 20 parts by weight with respect to 100 parts by weight of the photocurable compound. More preferably, it is 15 parts by weight or less, more preferably less than 10 parts by weight, still more preferably 8 parts by weight or less, particularly preferably less than 6 parts by weight, most preferably 5 parts by weight or less. The content of the (C) thiol group-containing compound is preferably 0.2 parts by weight or more, more preferably 1 part by weight based on 100 parts by weight of the total of (A) the photocurable compound and (B) the reactive diluent. Part or more, preferably 20 parts by weight or less, more preferably 10 parts by weight or less, still more preferably 6 parts by weight or less. (C) When the content of the thiol group-containing compound is not less than the above lower limit and not more than the above upper limit, peeling and discoloration in the resist cured product layer are further suppressed. Further, when the content of the (C) thiol group-containing compound is not more than the above upper limit, gelation hardly proceeds during storage. (C) Curability becomes still higher that content of a thiol group containing compound is more than the above-mentioned minimum.

((D) White pigment)
When the said photocurable composition contains (D) white pigment, the resist cured material layer with a high reflectance of light can be formed. (D) By using a white pigment, compared with the case where only fillers other than (D) white pigment are used, the resist cured material layer with a high reflectance of light is obtained. (D) As for a white pigment, only 1 type may be used and 2 or more types may be used together.

  (D) Examples of white pigments include alumina, titanium oxide, zinc oxide, zirconium oxide, antimony oxide, and magnesium oxide.

  From the viewpoint of further increasing the light reflectance of the cured resist layer, the (D) white pigment is preferably titanium oxide, zinc oxide or zirconium oxide. When this preferred white pigment is used, one or more white pigments can be used among titanium oxide, zinc oxide and zirconium oxide. (D) The white pigment is preferably titanium oxide or zinc oxide, preferably titanium oxide, and preferably zinc oxide. (D) The white pigment may be zirconium oxide.

  The titanium oxide is preferably rutile titanium oxide. By using the rutile type titanium oxide, the heat resistance of the resist cured product layer is further increased, and discoloration of the resist cured product layer is further suppressed.

  The titanium oxide is preferably rutile type titanium oxide surface-treated with aluminum oxide. The use of rutile-type titanium oxide surface-treated with the aluminum oxide further increases the heat resistance of the resist cured product layer.

  Examples of the rutile-type titanium oxide surface-treated with the aluminum oxide include, for example, “CR-90-2” manufactured by Ishihara Sangyo Co., Ltd., which is rutile chlorine method titanium oxide, and “CR, manufactured by Ishihara Sangyo Co., Ltd., which is rutile chlorine method titanium oxide -58 "," R-900 "manufactured by DuPont which is rutile chlorine method titanium oxide, and" R-630 "manufactured by Ishihara Sangyo Co., Ltd. which is rutile sulfuric acid method titanium oxide.

  The zinc oxide is preferably surface-treated zinc oxide. From the viewpoint of further improving the workability of the resist cured product layer and the light reflectance, the zinc oxide is preferably surface-treated with a material containing silicon, aluminum or zirconia, and the surface treatment with a material containing silicon. More preferably. The material containing silicon is preferably a silicone compound.

  The zirconium oxide is preferably surface-treated zirconium oxide. From the viewpoint of further increasing the light reflectance of the cured resist layer, the zirconium oxide is preferably surface-treated with a material containing silicon, aluminum or zirconia, and is surface-treated with a material containing silicon. It is more preferable. The material containing silicon is preferably a silicone compound.

  The surface treatment method is not particularly limited. As a surface treatment method, a dry method, a wet method, an integral blend method, and other known and commonly used surface treatment methods can be used.

  (D) The average particle diameter of the white pigment is preferably 0.1 μm or more, and preferably 40 μm or less. The reflectance of the light of a resist hardened | cured material layer can be further improved as the said average particle diameter is more than the said minimum and below the said upper limit.

  The average particle diameter is a particle diameter value when the integrated value is 50% in the volume-based particle size distribution curve. The average particle size can be measured using, for example, a laser beam type particle size distribution meter. As a commercial product of the laser beam type particle size distribution analyzer, “LS 13 320” manufactured by Beckman Coulter, Inc. can be cited.

  In 100% by weight of the photocurable composition, the content of the (D) white pigment is preferably 10% by weight or more, more preferably 20% by weight or more, still more preferably 30% by weight or more, and particularly preferably 35% by weight. Above, preferably 80% by weight or less, more preferably 70% by weight or less, and still more preferably 60% by weight or less. In 100% by weight of the photocurable composition, the content of the (D) white pigment is preferably 10% by weight or more and 80% by weight or less, and more preferably 20% by weight or more and 70% by weight or less. Preferably, it is 30 wt% or more and 60 wt% or less. (D) When the content of the white pigment is not less than the above lower limit and not more than the above upper limit, the light reflectance of the resist cured product layer is further increased, and the adhesion of the resist cured product layer is further enhanced. In 100% by weight of the photocurable composition, the content of the (D) white pigment may be 50% by weight or more.

((E) Photopolymerization initiator)
Since the said photocurable composition contains the photoinitiator (E), a photocurable composition can be hardened by irradiation of light. (E) As for a photoinitiator, only 1 type may be used and 2 or more types may be used together.

  (E) As a photopolymerization initiator, acylphosphine oxide, halomethylated triazine, halomethylated oxadiazole, imidazole, benzoin, benzoin alkyl ether, anthraquinone, benzanthrone, benzophenone, acetophenone, thioxanthone, benzoate, acridine, Examples include phenazine, titanocene, α-aminoalkylphenone, oxime, and derivatives thereof.

  Examples of the benzophenone photopolymerization initiator include methyl o-benzoylbenzoate and Michler's ketone. EAB (made by Hodogaya Chemical Co., Ltd.) etc. are mentioned as a commercial item of a benzophenone series photoinitiator.

  Examples of commercially available acetophenone photopolymerization initiators include Darocur 1173, Darocur 2959, Irgacure 184, Irgacure 907, and Irgacure 369 (manufactured by Ciba Specialty Chemicals).

  Examples of commercially available benzoin photopolymerization initiators include Irgacure 651 (manufactured by Ciba Specialty Chemicals).

  Examples of commercially available acylphosphine oxide photopolymerization initiators include Lucirin TPO (manufactured by BASF) and Irgacure 819 (manufactured by Ciba Specialty Chemicals).

  Examples of commercially available thioxanthone photopolymerization initiators include isopropyl thioxanthone and diethyl thioxanthone.

  From the viewpoint of further suppressing peeling and discoloration, the (E) photopolymerization initiator preferably contains both an acetophenone photopolymerization initiator and an acylphosphine oxide photopolymerization initiator. It is also preferable to include both an oxide photopolymerization initiator and a bisacylphosphine oxide photopolymerization initiator.

  The content of (E) the photopolymerization initiator is preferably 1 part by weight or more, more preferably 3 parts by weight or more based on 100 parts by weight of the total of (A) the photocurable compound and (B) the reactive diluent. , Preferably 20 parts by weight or less, more preferably 15 parts by weight or less. (E) When content of a photoinitiator is more than the said minimum and below the said upper limit, a photocurable composition can be photocured favorably.

((F) thermosetting compound)
The photocurable composition preferably does not contain (F) a thermosetting compound or contains (F) a thermosetting compound at 5% by weight or less. In the present invention, when the (F) thermosetting compound is used, it is preferable to reduce the amount of the (F) thermosetting compound used. (F) The composition having a thermosetting compound content of 5% by weight or less and the composition (F) having a thermosetting compound content of, for example, 10% by weight or more have a basic physical property of the cured product. Generally different. (F) As for a thermosetting compound, only 1 type may be used and 2 or more types may be used together.

  (F) An epoxy compound etc. are mentioned as a thermosetting compound.

  It is preferable that the said photocurable composition does not contain an epoxy compound or contains an epoxy compound at 5 weight% or less.

  From the viewpoint of further suppressing peeling and discoloration, the content of the (F) thermosetting compound is preferably as small as possible in 100% by weight of the photocurable composition. In 100% by weight of the photocurable composition, the content of the (F) thermosetting compound is preferably 3% by weight or less, more preferably 1% by weight or less, still more preferably 0.5% by weight or less, particularly preferably 0. % By weight (unused).

(Other ingredients)
It is preferable that the said photocurable composition contains a stabilizer other than the component mentioned above. Even if the (C) thiol group containing compound is used because the said photocurable composition contains a stabilizer, gelatinization and a viscosity change during storage are further suppressed. Specifically, for example, compounds described in JP-A-5-155987 and JP-A-2012-17448 can be used as the stabilizer.

  In addition to the components described above, the photocurable composition includes a solvent, an inorganic filler other than a white pigment, an organic filler, a colorant, a polymerization inhibitor, a chain transfer agent, an antioxidant, an ultraviolet absorber, an antifoaming agent, and leveling. Agents, surfactants, slip agents, anti-blocking agents, waxes, masking agents, deodorants, fragrances, preservatives, antibacterial agents, antistatic agents, and adhesion-imparting agents. Examples of the adhesion imparting agent include silane coupling agents.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited only to the following examples.

Example 1
(1) Preparation of non-development type photocurable composition The compounding component shown below was mix | blended with the compounding quantity shown below, and the non-development type photocurable composition was prepared.

(A) 20 parts by weight of photocurable compound Bisphenol A type epoxy acrylate (Ebecryl 3700, manufactured by Daicel Ornex)
(B) 30 parts by weight of reactive diluent having one or more ethylenically unsaturated bonds Mixture of TMPTA (trimethylolpropane triacrylate) and DPGDA (dipropylene glycol diacrylate) (C) Thiol having one or more thiol groups 1 part by weight of group-containing compound TMMP
(D) White pigment 30 parts by weight Titanium oxide (manufactured by Ishihara Sangyo Co., Ltd., CR-90)
(E) Photopolymerization initiator 5 parts by weight A mixture of TPO (manufactured by BASF) and Irgacure 819 (manufactured by BASF)

(2) Production of electronic component A substrate was prepared by laminating copper foil on FR-4 having a size of 100 mm x 100 mm x thickness 0.8 mm. On this substrate, a non-developable photocurable composition was screen-printed once with a mask pattern using a 180 mesh polyester-biased plate by screen printing to form a first resist layer. After printing, in order to irradiate the first resist layer with ultraviolet rays having a wavelength of 365 nm, the first resist cured product layer is flowed once with a belt conveyor type ultraviolet irradiator so that the irradiation energy is 1500 mJ / cm ^2. Formed. Next, a non-developable photocurable composition is screened once with a mask pattern on the first resist cured material layer located on the substrate by a screen printing method using a 180 mesh polyester bias plate. Printing was performed to form a second resist layer. After printing, in order to irradiate the second resist layer with ultraviolet light having a wavelength of 365 nm, the second resist cured product layer is flowed once with a belt conveyor type ultraviolet irradiator so that the irradiation energy is 1500 mJ / cm ^2. Formed. Next, a non-developable photocurable composition is screened once with a mask pattern on the second resist cured product layer located on the substrate using a 180 mesh polyester bias plate by screen printing. Printing was performed to form a third resist layer. After printing, in order to irradiate the third resist layer with ultraviolet light having a wavelength of 365 nm, the third resist cured product layer is flowed once with a belt conveyor type ultraviolet irradiator so that the irradiation energy is 1500 mJ / cm ^2. Formed. In this way, a three-layer resist cured product layer as a measurement sample was formed to obtain an electronic component. The total thickness of the obtained three resist cured product layers was 60 μm. The average thickness per layer of the obtained three resist cured product layers was 20 μm. In addition, the thickness of the 1st resist cured material layer, the thickness of the 2nd resist cured material layer, and the thickness of the 3rd resist cured material layer were substantially the same.

(Example 2)
Example 1 except that the total thickness of the obtained three resist cured product layers was changed to 90 μm, and the average thickness per layer of the obtained three resist cured product layers was changed to 30 μm. In the same manner, an electronic component was obtained. The thickness of the resist layer was adjusted according to the mesh size and printing conditions during screen printing.

(Example 3)
Example 1 except that the total thickness of the obtained three resist cured product layers was changed to 21 μm and the average thickness per layer of the obtained three resist cured product layers was changed to 7 μm. In the same manner, an electronic component was obtained. The thickness of the resist layer was adjusted according to the mesh size and printing conditions during screen printing.

Example 4
The number of screen printings was changed to 2 to form two resist layers and two cured resist layers, and the total thickness of the resulting two resist cured layers was changed to 40 μm. In addition, an electronic component was obtained in the same manner as in Example 1 except that the average thickness per layer of the obtained two resist cured product layers was changed to 20 μm. The thickness of the resist layer was adjusted according to the mesh size and printing conditions during screen printing.

(Comparative Example 1)
(1) Preparation of non-developable thermosetting composition An electronic component was prepared using the thermosetting resin shown below.

  RG-12-6-2 (Furukawa Chemicals, silicone-based thermosetting resin composition)

(2) Production of electronic component A substrate was prepared by laminating copper foil on FR-4 having a size of 100 mm x 100 mm x thickness 0.8 mm. On this substrate, a non-developable thermosetting composition is screen-printed once with a mask pattern using a 180 mesh polyester bias plate by screen printing, and dried at 80 ° C. for 30 minutes. The resist layer was formed. Next, a non-developable thermosetting composition was screen-printed once with a mask pattern on the first resist layer located on the substrate by a screen printing method using a 180 mesh polyester bias plate. And dried at 80 ° C. for 30 minutes to form a second resist layer. Next, by screen printing, a non-developable thermosetting composition was screen-printed once with a mask pattern on the second resist layer located on the substrate, using a 180 mesh polyester bias plate. And dried at 80 ° C. for 30 minutes to form a third resist layer. Furthermore, by thermosetting at 150 ° C. for 1 hour, a three-layer resist cured product layer as a measurement sample was formed, and an electronic component was obtained. The total thickness of the obtained three resist cured product layers was 45 μm. The average thickness per layer of the obtained three resist cured product layers was 15 μm.

(Comparative Example 2)
(1) Preparation of development type light / thermosetting composition The compounding component shown below was mix | blended with the compounding quantity shown below, and the non-development type photocurable composition was prepared.

(A) 50 parts by weight of photocurable compound Acid group-containing acrylate (manufactured by Daicel Ornex Co., (ACA) Z250)
(B) 10 parts by weight of reactive diluent having one or more ethylenically unsaturated bonds TMPTA (trimethylolpropane triacrylate)
(D) White pigment Titanium oxide (manufactured by Ishihara Sangyo Co., Ltd., CR-90) 40 parts by weight (E) Photopolymerization initiator 2 parts by weight A mixture of TPO (manufactured by BASF) and Irgacure 819 (manufactured by BASF) (F) Bisphenol A Type epoxy resin (manufactured by Mitsubishi Chemical Corporation, JER828) 5 parts by weight (other components)
Propylene glycol ethyl ether acetate

(2) Production of electronic component A substrate was prepared by laminating copper foil on FR-4 having a size of 100 mm x 100 mm x thickness 0.8 mm. On this substrate, a screen-printing method is used to screen-print the development type photo-thermosetting composition once on the entire surface using a 100 mesh polyester-biased plate, followed by drying at 80 ° C. for 30 minutes. The resist layer was formed. Next, a screen-printing method is used to screen-print the development type photo / thermosetting composition once on the entire surface of the first resist layer using a 100 mesh polyester bias plate at 80 ° C. and 30 ° C. A second resist layer was formed by drying for a minute. Next, a screen-printing method is used to screen-print the development type photo / thermosetting composition once on the entire surface of the second resist layer located on the substrate using a 100 mesh polyester bias plate. And dried at 80 ° C. for 30 minutes to form a third resist layer. Next, exposure was performed at 1000 mJ through a mask pattern, and after pattern formation by alkali development, heat curing was performed at 150 ° C. for 1 hour to form a three-layer resist cured product layer as a measurement sample, thereby obtaining an electronic component. . The total thickness of the obtained three resist cured product layers was 60 μm. The average thickness per layer of the obtained three resist cured product layers was 20 μm.

(Comparative Example 3)
The number of screen printings was changed to 2 to form two resist layers and two cured resist layers, and the total thickness of the obtained two resist cured layers was changed to 30 μm. In addition, an electronic component was obtained in the same manner as in Comparative Example 1 except that the average thickness per layer of the obtained two resist cured product layers was changed to 15 μm.

(Comparative Example 4)
The number of screen printings was changed to 2 to form two resist layers and two cured resist layers, and the total thickness of the resulting two resist cured layers was changed to 40 μm. In addition, an electronic component was obtained in the same manner as in Comparative Example 2 except that the average thickness per layer of the obtained two resist cured product layers was changed to 20 μm. The thickness of the resist layer was adjusted according to the mesh size and printing conditions during screen printing.

(Comparative Example 5)
In order to form a two-layer resist cured product layer comprising a thermosetting type and a development type, the first layer is the same as the first layer of Comparative Example 1, and the second layer is the same as the second layer of Comparative Example 2. To obtain an electronic component. The total thickness of the obtained two resist cured product layers was 35 μm.

(Comparative Example 6)
In order to form a two-layer cured resist layer consisting of a thermosetting type and a development type, the first layer is the same as the first layer of Comparative Example 2, and the second layer is the same as the second layer of Comparative Example 1. To obtain an electronic component. The total thickness of the obtained two resist cured product layers was 35 μm.

(Evaluation)
(1) Light reflectivity In the formed resist cured material layer, the light reflectivity was evaluated by using a color / color difference meter (CR-400, manufactured by Konica Minolta Co., Ltd.).

[Judgment criteria for light reflectance]
○○: 90% or more ○: 85% or more and less than 90%

(2) Resolution The wiring pattern of L / S = 200/200 [μm] was observed with an optical microscope, and the resolution was evaluated by measuring the Line width and the Space width. The resolution was judged according to the following criteria.

[Resolution criteria]
○: L / S: 200 or more and less than 250/150 or more and less than 200 ×: L / S: 250 or more and less than 300/100 or more and less than 150

(3) Undercut prevention The undercut prevention was evaluated from the pattern width of the resist cured product layer in contact with the substrate and the pattern width of the outermost surface by observing a cross section of the pattern formation portion with an optical microscope. Undercut prevention was determined according to the following criteria. In addition, when the pattern width which contacts the board | substrate of a resist cured material layer was narrower than the pattern width of the outermost surface, the recessed part was formed in the outer peripheral surface of a resist cured material layer.

[Criteria for undercut prevention]
○: Pattern width in contact with substrate ≧ pattern width on outermost surface ×: Pattern width in contact with substrate <pattern width on outermost surface

(4) Migration resistance A sample coated with a resist on a comb-shaped pattern substrate is subjected to a migration resistance test for 1000 hours at a voltage value of 100 V in an environment of 85 ° C. and a humidity of 85% RH, thereby evaluating migration resistance. did. Migration resistance was determined according to the following criteria.

[Judgment criteria for migration resistance]
Y: No migration occurred X: Migration occurred

  The composition and results are shown in Table 1 below.

DESCRIPTION OF SYMBOLS 1 ... Electronic component 2 ... Multi-layered resist cured material layer 2A-2C ... Resist cured material layer 11 ... Electronic component main body (coating object member)
11A ... substrate 11B ... electrode
12 ... Multiple resist layers (before curing)
12A-12C ... resist layer (before curing)

Claims (11)

A non-developable photocurable composition comprising a photocurable compound, a photopolymerization initiator, and a white pigment, which can be cured by light irradiation and can form a cured resist layer without development. A first step of forming a plurality of resist layers in a pattern without development on the surface of the electronic component body using
And a second step of irradiating the plurality of resist layers with light to cure the plurality of resist layers to form a plurality of resist cured product layers.   2. The method for producing an electronic component according to claim 1, wherein the content of the white pigment in the non-developable photocurable composition is 10 wt% or more and 80 wt% or less.   The manufacturing method of the electronic component of Claim 1 or 2 in which the said non-development type photocurable composition contains the thiol group containing compound which has one or more thiol groups.   The manufacturing method of the electronic component of any one of Claims 1-3 whose sum total thickness of the said several resist hardened | cured material layer is 20 micrometers or more and 90 micrometers or less.   The manufacturing method of the electronic component of any one of Claims 1-4 whose average thickness per layer of the said multiple-layered resist cured material layer is 5 micrometers or more and 40 micrometers or less.   The method for manufacturing an electronic component according to claim 1, wherein the plurality of resist layers are formed by screen printing.   The resist layer according to any one of claims 1 to 6, wherein three or more resist layers are formed as the plurality of resist layers, and three or more resist cured product layers are formed as the plurality of resist cured product layers. 2. A method for manufacturing an electronic component according to item 1.   After forming a part of the plurality of resist layers, the part of the resist layer is irradiated with light to cure the part of the resist layer to form a part of the resist cured product layer. And then forming another resist layer of the plurality of resist layers, irradiating the other resist layer with light, curing the other resist layer, and The manufacturing method of the electronic component of any one of Claims 1-7 which forms the multiple-layered resist hardened | cured material layer containing a hardened | cured material layer and another resist hardened | cured material layer.   After forming all the resist layers of the plurality of resist layers, irradiating all the resist layers with light to cure all the resist layers to form a plurality of resist cured product layers. The manufacturing method of the electronic component of any one of 1-7. The first step includes a photocurable compound, a photopolymerization initiator, and a white pigment as the non-developable photocurable composition, is curable by light irradiation, and is not developed. On the surface of the electronic component body using the first composition capable of forming a cured resist layer on the surface of the electronic component body in a pattern without development, the first resist layer is formed as one layer of the plurality of resist layers. A step of forming a resist layer; and the non-developable photocurable composition, which includes a photocurable compound, a photopolymerization initiator, and a white pigment, is curable by light irradiation, and is developed Without using the second composition that is capable of forming a cured resist layer without developing the pattern on the surface of the first resist layer opposite to the electronic component body side, A second resist layer is formed as one of a plurality of resist layers. And a degree,
In the second step, the first resist layer is irradiated with light to cure the first resist layer, so that the first resist layer is formed as one layer of the plurality of resist cured layers. And irradiating the second resist layer with light, curing the second resist layer, and forming a second resist cured product layer as one layer of the plurality of resist cured product layers. The manufacturing method of the electronic component of any one of Claims 1-9 including the process to form. The first step includes a photocurable compound, a photopolymerization initiator, and a white pigment as the non-developable photocurable composition, is curable by light irradiation, and is not developed. On the surface opposite to the first resist layer side of the second resist layer, using a third composition that can form a resist cured product layer in a pattern without development, A step of forming a third resist layer as one of the plurality of resist layers;
In the second step, the third resist layer is irradiated with light to cure the third resist layer, thereby forming a third resist cured product layer as one layer of the plurality of resist cured product layers. The manufacturing method of the electronic component of Claim 10 including the process of forming.

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