JP6208414B2 - Solder heat treatment jig - Google Patents

Description

  The present invention relates to a solder heat treatment jig. More specifically, in the process of reflowing solder onto the substrate and mounting the element (reflow process), it is due to bumping of the flux generated in the heating furnace (also referred to as “solder reflow furnace”) in which the solder is melted. TECHNICAL FIELD The present invention relates to a jig (solder heat treatment jig) for preventing adhesion of solder droplets to a substrate and suppressing defects of the mounted substrate, and a mounting electronic circuit board manufacturing method using the jig. Is.

  When an element is mounted on a substrate with solder, a solvent contained in the solder bumps, and a part of the flux contained in the solder or a solder having a small diameter of about several tens of microns may be scattered on the substrate. When there is a lot of flux scattering, it is determined that the appearance of the substrate is poor, and the yield is reduced. When the solder is scattered, the generated solder balls may adhere to the electrode of the element or the electronic wiring on the substrate, which causes the characteristics and reliability of the substrate circuit to be significantly reduced. Attempts have also been made to provide a shutter in the heating device to prevent the flux and solder from scattering (Patent No. 3897715; Patent Document 1). There has also been proposed a mechanism for moving a flux scattering prevention jig up and down on a substrate (Japanese Patent Laid-Open No. 2009-212431; Patent Document 2). However, when mounting various substrates with a single device, it is necessary to design a shutter or anti-scattering jig according to the substrate, and the device must be modified significantly. This is not applicable when manufacturing a wide variety of products.

  Further, when mounting an insertion mounting component, it is necessary to confirm that the component to be mounted is held at a predetermined position. Therefore, the conventional jig is provided with an opening, and the position is confirmed through the opening. Although it is physically possible to completely enclose the surrounding area, the fact is that it is impossible to confirm whether the part is pressed or the state of the solder.

  The use of heat-resistant glass as a window material for conventional jigs is also being studied, but it is difficult to process into shapes that match the jigs and cannot be made thinner. For this reason, the weight is heavy and the heat capacity becomes large, so that the temperature becomes non-uniform, and it cannot be installed in a narrow area. In addition, it is necessary to prepare a large variety of jigs and a small amount of jigs, but this jig is difficult to adapt to a reflow jig because of its high price. In addition, inorganic glass materials are vulnerable to thermal shock and are easily damaged. It is unsuitable for applications that require repeated temperature histories such as reflow processes. In the unlikely event of breakage, a glass component may be contaminated in the solder bath, and a material having a low elastic modulus that is resistant to impact and that does not contaminate the solder even if broken is preferable.

Japanese Patent No. 3897715 JP 2009-212431 A

  Accordingly, an object of the present invention is to provide a jig that can sufficiently reduce the scattering area of flux and solder balls in a reflow process, and can be freely designed according to various substrates.

  When mounting elements on a board using a solder reflow furnace, in order to prevent the flux and solder balls from scattering, the jig is designed with an optimized shape to minimize the scattering area for each board or element. do it. If the jig can be miniaturized and a highly sealed jig can be designed for each substrate or element, this problem can be solved. In general, such a jig is made of a metal, a polyether ether ketone (PEEK) material having high heat resistance, or an epoxy reinforced with glass fiber.

  However, when a jig is made of such a material, it does not transmit visible light, so it can be confirmed whether the jig is actually set in an optimum state (whether the element is mounted at a predetermined location). In addition, since a member that does not transmit light normally does not transmit infrared rays, the temperature is not uniform on the substrate, and there is a problem that solder mounting cannot be performed under a uniform temperature condition.

As a result of diligent efforts to solve the above-mentioned problems, the present inventors have made a heat-resistant resin plate (hereinafter referred to as “heat-resistant transparent resin plate”) capable of transmitting light through all or a part thereof (at least the window). The present invention was completed by producing a solder heat treatment jig.
That is, the present invention relates to the following [1] to [11].

[1] A jig (solder for heat treatment of solder) for preventing adhesion of solder droplets to the board due to bump bumping of the flux used in the step of mounting the element by reflowing solder onto the board. A jig for solder heat treatment, characterized in that all or part of the tool is formed of a heat-resistant transparent resin plate.
[2] The solder heat treatment jig according to item 1, wherein at least the window is formed of a heat-resistant transparent resin plate.
[3] The solder heat treatment jig according to item 1 or 2, wherein the heat-resistant transparent resin plate has an elastic modulus of 2.5 to 3.5 GPa.
[4] The solder heat treatment jig according to any one of items 1 to 3, wherein the heat-resistant transparent resin plate has heat resistance of 200 ° C. or higher.
[5] The jig for solder heat treatment as described in 4 above, wherein a heat shrinkage rate at 200 ° C. with respect to a heat-resistant transparent resin plate at room temperature (20 ° C.) is 0.5% or less.
[6] The solder heat treatment jig as described in any one of 1 to 5 above, wherein the surface hardness of the heat-resistant transparent resin plate is a pencil hardness H or more.
[7] The solder heat treatment jig according to any one of [1] to [6], wherein the heat-resistant transparent resin plate has a visible light transmittance of 85% or more and an infrared transmittance of 50% or more.
[8] The jig for solder heat treatment as described in any one of 1 to 7 above, wherein the heat-resistant transparent resin plate has a thickness of 0.1 mm or more and 1.5 mm or less.
[9] The solder heat treatment jig according to any one of items 1 to 8, wherein the heat-resistant transparent resin plate is made of a thermosetting resin.
[10] The solder heat treatment jig as recited in the aforementioned Item 9, wherein the thermosetting resin is an allyl ester resin.
[11] The element is brought into contact with the conductive circuit on the substrate via cream solder, the element is covered with the solder heat treatment jig described in any one of 1 to 10 above, and the cream solder is reflowed in a heating furnace. And electrically connecting the conductive circuit and the element.

  According to the solder heat treatment jig of the present invention formed entirely or partially with a heat-resistant transparent resin plate, it can be easily confirmed whether or not the substrate or the element can be set at an optimum position with respect to the solder heat treatment jig. . In addition, the jig can be reduced in size and weight by selecting a resin with a high elastic modulus, and by using a resin plate that is permeable to not only visible light but also infrared rays, Since the temperature becomes uniform, a large difference in the in-plane temperature distribution of the substrate does not occur even when a jig is set, and a mounted electronic circuit substrate having no variation under a uniform temperature condition can be efficiently manufactured.

It is a perspective view of an example of the jig for solder heat treatment of the present invention. It is a perspective view (A) of other examples of the jig for solder heat treatment of the present invention, and a sectional view (B) showing the outline of the state where the above-mentioned jig is used for the substrate on which the element is mounted. It is sectional drawing which shows the outline | summary of the state which used the other Example of the jig for soldering heat processing of this invention on the board | substrate which mounted the element.

  In the present invention, in the process of mounting the element by reflowing the solder on the substrate, all or part of a jig (solder heat treatment jig) for preventing adhesion of solder droplets to the substrate due to bump bumping of the flux. And a heat-resistant resin plate that can transmit light (abbreviated as “heat-resistant transparent resin plate”). When using a heat-resistant transparent resin plate as a part of a jig for solder heat treatment, at least the window is made of a heat-resistant transparent resin plate, and the frame material that forms the framework of the jig is made of another heat-resistant resin. can do.

  The heat-resistant transparent resin plate used in the present invention preferably has an elastic modulus of 2.5 to 3.5 GPa at room temperature. When the elastic modulus is lower than 2.5 GPa, it is necessary to reinforce the member that holds the heat-resistant transparent resin plate, resulting in an increase in the weight of the jig. Further, when the elastic modulus is higher than 3.5 GPa, the toughness is lowered, so that the jig is easily broken and the durability is inferior.

  The surface hardness of the heat-resistant transparent resin plate is preferably pencil hardness H or higher, and more preferably 3H or higher. When the surface hardness is low, the surface is scratched by contact with the substrate or other members, and the light transmittance is deteriorated. In order to increase the surface hardness, another member having transparency and heat resistance may be coated.

  In order for the operator to confirm the position of the substrate or element when setting the jig, the heat-resistant transparent resin plate preferably has a transmittance of 85% or more in the visible light region. In order to make the temperature uniform, it is preferable that 50% or more of infrared rays can be transmitted.

  As the heat-resistant transparent resin plate becomes thicker, the mechanical strength is increased accordingly, but the weight and heat capacity are excessive, and the light transmittance is inferior. Moreover, in order to set a jig in an element and a narrow area of the element, a thinner one is better. However, if it is thinner than 0.1 mm, it is difficult to hold the jig, and a certain thickness is required. Therefore, the thickness of the transparent resin plate is preferably 0.1 mm or more and 1.5 mm or less, and more preferably 0.3 to 1.0 mm.

  The heat resistance of the heat-resistant transparent resin plate is as follows. The heat shrinkage rate at 200 ° C. relative to the heat-resistant transparent resin plate at room temperature (20 ° C.), that is, the heat shrinkage rate when held at 200 ° C. for about 5 minutes is normal temperature (20 ° C. ) To 0.5% or less, preferably 0.2% or less. If the heat shrinkage rate exceeds 0.5%, the heat-resistant transparent resin plate is deformed due to heat shrinkage, so that the jig cannot be used repeatedly.

  The solder heat treatment jig of the present invention is directly exposed not only to heat but also to a flux component contained in the solder and a decomposition component of the solder. Therefore, it is necessary to clean these dirt components after use. Therefore, it is necessary to select a resin that can withstand acid, alkali, and organic solvent as the resin for the heat-resistant transparent resin plate.

  Such a heat-resistant transparent resin can be selected by using a transparent heat-resistant resin that does not contain halogen, alkali, or other heavy metals.

  As the resin, it is possible to use a thermoplastic resin having high heat resistance, but a thermosetting resin is preferable for repeated use at high temperatures. For example, epoxy resin, urethane resin, acrylic resin, urethane acrylate resin, unsaturated polyester resin, vinyl ester resin, silicone resin, silsesquioxane acrylic resin, allyl ester resin and the like can be mentioned. Among them, allyl ester resins are particularly preferable because they are excellent in heat resistance, transparency, and chemical resistance. These resins are used alone, but can be used as a composition as long as heat resistance and transparency can be maintained.

  Furthermore, an inorganic substance can also be mix | blended if it is a range which does not impair transparency for the rigidity improvement of a transparent heat resistant resin board. Examples of these inorganic substances include glass filler, silica, aluminum oxide, titanium oxide, and clay. The size of these inorganic materials is not particularly limited as long as the transparency is not impaired, but is preferably 10 nm to 50 μm from the viewpoint of maintaining transparency.

  As the material for the transparent heat-resistant resin plate used for the solder heat treatment jig of the present invention, an allyl ester resin is particularly preferable. Hereinafter, this allyl ester resin will be described in detail.

[Allyl ester resin]
In general, the term “allyl ester resin” refers to a prepolymer (including an oligomer, an additive, a reactive monomer (also referred to as “reactive diluent”), and a solvent) before curing, and a cured product thereof. In this specification, “allyl ester resin” indicates a cured product, and “allyl ester resin composition” indicates a prepolymer before curing.

[Allyl ester resin composition]
The allyl ester resin composition used in the present invention is a compound having an allyl group or a methallyl group (hereinafter sometimes referred to as a (meth) allyl group as well as (meth) allyl alcohol) and an ester structure. It is a composition contained as a main curing component.

  The compound having a (meth) allyl group and an ester structure is (1) a compound containing a (meth) allyl group and a hydroxyl group (in order to simplify the expression, hereinafter referred to as “(meth) allyl alcohol”) and carboxyl. Esterification reaction with a compound containing a group, (2) esterification reaction between a compound containing a (meth) allyl group and a carboxyl group and a compound containing a hydroxyl group, or (3) an ester comprising (meth) allyl alcohol and a dicarboxylic acid It can be obtained by a transesterification reaction between a compound and a polyhydric alcohol. When the compound containing a carboxyl group is a polyester oligomer of a dicarboxylic acid and a diol, only the terminal can be an ester with (meth) allyl alcohol.

Specific examples of the ester compound composed of (meth) allyl alcohol and dicarboxylic acid include at least one compound selected from compounds represented by the following general formula (1). In addition to being a raw material for the allyl ester oligomer described later, this compound may be contained in the allyl ester resin composition of the present invention as a reactive diluent (reactive monomer).
(R ¹ and R ² each independently represent either a hydrogen atom or a methyl group, and A ¹ is one or more organic compounds having an alicyclic structure and / or an aromatic ring structure derived from a dicarboxylic acid. Represents a residue.)

A ¹ in general formula (1) is preferably the same as A ² and A ³ in general formula (2) and general formula (3) described later.

  As a compound having an (meth) allyl group and an ester structure, which is the main curing component of the allyl ester resin composition, an ester formed from a polyhydric alcohol and a dicarboxylic acid having an allyl group and / or a methallyl group as a terminal group It is preferably an allyl ester compound having a structure (hereinafter, this may be referred to as “allyl ester oligomer”). The allyl ester resin composition may contain a curing agent, a reactive diluent, other monomers, additives, other radical-reactive resin components, etc., which will be described later, as components other than the above compounds.

[Allyl ester oligomer]
The main component of the allyl ester resin composition used in the present invention is an allyl ester having a group represented by the following general formula (2) as a terminal group and a structure represented by the following general formula (3) as a structural unit. An oligomer is preferable.
(Wherein R ³ represents a hydrogen atom or a methyl group, and A ² represents one or more organic residues having an alicyclic structure and / or an aromatic ring structure derived from dicarboxylic acid.)
(Wherein, A ³ represents one or more organic residue having an alicyclic structure and / or aromatic ring structure derived from dicarboxylic acid, X represents one or more organic residues derived from a polyhydric alcohol However, X can form a branched structure having a group represented by the general formula (2) as a terminal group and a structure represented by the general formula (3) as a structural unit by an ester bond.)

In the allyl ester oligomer, the number of terminal groups represented by the general formula (2) is at least 2 or more, but when X in the general formula (3) has a branched structure, the number is 3 or more. In this case, although also R ³ at each end groups there are a plurality, each of these R ³ may not necessarily be the same type, some end there in the structure of an allyl group, the other terminal methallyl group It doesn't matter. Further, all the terminals need not be allyl groups or methallyl groups, and a part thereof may be a non-polymerizable group such as a methyl group or an ethyl group as long as the curability is not impaired. Similarly, the structure represented by A ² may be different for each terminal group. For example, A ^{2 at} one terminal may be a benzene ring and the other may be a cyclohexane ring.

A ² in the general formula (2) is one or more organic residues having an alicyclic structure and / or an aromatic ring structure derived from a dicarboxylic acid. The moiety derived from the dicarboxylic acid is indicated by a carbonyl structure adjacent to A ² . Therefore, A ² represents a benzene skeleton or a cyclohexane skeleton.

There are no particular limitations on the dicarboxylic acid to induce A ² structure, from the viewpoint of ready availability of raw materials, terephthalic acid, isophthalic acid, phthalic acid, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic Acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diphenyl-m, m′-dicarboxylic acid, diphenyl-p, p′-dicarboxylic acid, benzophenone-4, 4′-dicarboxylic acid, p-phenylenediacetic acid, p-carboxyphenylacetic acid, methyl terephthalic acid and tetrachlorophthalic acid are preferred, and terephthalic acid, isophthalic acid, phthalic acid and 1,4-cyclohexanedicarboxylic acid are particularly preferred. Among these, it is preferable to use 1,4-cyclohexanedicarboxylic acid having no aromatic ring in the molecule from the viewpoint of light resistance, and it is preferable to use 1,4-cyclohexanedicarboxylic acid for applications requiring high transparency.

In addition to the dicarboxylic acid for deriving the A ² structure, maleic acid, fumaric acid, itaconic acid, citraconic acid, endic acid anhydride, chlorendic anhydride, etc. A) acyclic dicarboxylic acids may be used.

  At least one structural unit represented by the general formula (3) is required in the allyl ester oligomer. However, when this structure is repeated, the molecular weight of the allyl ester oligomer as a whole increases to some extent, thereby obtaining an appropriate viscosity. Therefore, workability is improved and the toughness of the cured product is also improved. However, if the molecular weight becomes too large, the molecular weight between cross-linking points of the cured product becomes too large, so that the glass transition temperature (Tg) is lowered and the heat resistance may be lowered. It is important to adjust to an appropriate molecular weight according to the application. The weight average molecular weight of the allyl ester oligomer is preferably 500 to 200,000, more preferably 1,000 to 100,000.

In addition, A ³ in the general formula (3) is one or more organic residues having an alicyclic structure and / or an aromatic ring structure derived from a dicarboxylic acid, and examples of the definition and preferred compounds thereof are the general formula (2). The same as A ² in FIG.

  X in the general formula (3) represents one or more organic residues derived from a polyhydric alcohol. The polyhydric alcohol is a compound having two or more hydroxyl groups, and X itself represents a skeleton portion other than the hydroxyl groups of the polyhydric alcohol. Since at least two hydroxyl groups in the polyhydric alcohol need only exist, if the polyhydric alcohol as a raw material is trivalent or more, that is, if there are three or more hydroxyl groups, there is an unreacted hydroxyl group. Also good. The carbon number of the polyhydric alcohol is preferably 2-20.

Among specific examples of the polyhydric alcohol having 2 to 20 carbon atoms, examples of the divalent alcohol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, , 5-pentanediol, neopentyl glycol, hexamethylene glycol , 1,4-cyclohexanedimethanol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, diethylene glycol, dipropylene glycol, Triethylene glycol, polyethylene glycol, ethylene oxide adduct of bisphenol-A, propylene oxide adduct of bisphenol-A, hydrogenated bisphenol A, 2,2- [4- (2-hydroxyethoxy) -3,5-dibromophenyl ] Propane, etc. Can be mentioned.
Specific examples of trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, dipenta et Risuritoru like. A mixture of two or more of these polyhydric alcohols may be used. Moreover, it is not limited to the above-mentioned specific example.

As the structural unit represented by the general formula (3) in the allyl ester oligomer, the same structural unit may be repeated or different structural units may be included. That is, the allyl ester oligomer may be a copolymer type. In this case, several types of X exist in one allyl ester oligomer. For example, a structure in which one of X is a residue derived from propylene glycol and the other X is a residue derived from trimethylolpropane may be employed. In this case, the allyl ester oligomer will be branched at the trimethylolpropane residue. There may be several types of A3 as well. The structural formulas in the case where R ³ is an allyl group, A ² and A ³ are residues derived from isophthalic acid, and X is propylene glycol and trimethylolpropane are shown below.

[Method for producing allyl ester oligomer]
The allyl ester oligomer used in the present invention can be produced by a transesterification reaction between an allyl ester monomer of a polycarboxylic acid and a polyhydric alcohol having 2 to 6 hydroxyl groups. The allyl ester monomer of polyvalent carboxylic acid is an ester of polyvalent carboxylic acid and (meth) allyl alcohol, and an allyl ester monomer of dicarboxylic acid is particularly preferable. Specifically, diallyl phthalate, diallyl isophthalate, diallyl terephthalate, diallyl 2,6-naphthalenedicarboxylate, diallyl 1,2-cyclohexanedicarboxylate, diallyl 1,3-cyclohexanedicarboxylate, 1,4-cyclohexanedicarboxylic Examples thereof include diallyl acid, diallyl endomethylenetetrahydrophthalate, diallyl methyltetrahydrophthalate, diallyl adipate, diallyl succinate, diallyl maleate and the like. Two or more of these allyl ester monomers can be used as necessary. Moreover, it is not limited to the above-mentioned specific example.

  As the polyhydric alcohol, the polyhydric alcohol that induces the aforementioned X structure is used.

  In order to obtain an allyl ester oligomer having a (meth) allyl ester group at the terminal, it is necessary to use fewer hydroxyl groups of a polyhydric alcohol than carboxyl groups of a divalent carboxylic acid.

  As the transesterification reaction catalyst used in the present invention, conventionally known transesterification catalysts can be used. Particularly preferred are alkali metals, alkaline earth metals and their oxides, and weak acid salts, Mn, U, Examples include Zn, Cd, Zr, Pb, Ti, Co, and Sn oxides, hydroxides, inorganic acid salts, alcoholates, organic acid salts, organic tin compounds such as dibutyltin oxide, dioctyltin oxide, and dibutyltin dichloride. be able to. Of these, dibutyltin oxide and dioctyltin oxide are preferable.

  The amount used varies depending on the activity of the catalyst, but should be an amount that can distill allyl alcohol at an appropriate rate. Generally, it is preferable to use about 0.0001 to 1% by mass, particularly preferably about 0.001 to 0.5% by mass with respect to the allyl ester monomer of the polyvalent carboxylic acid.

The reaction temperature in this production process is not particularly limited, but is preferably in the range of 120 to 230 ° C, more preferably in the range of 140 to 200 ° C.
In order to promote the progress of the reaction, it is necessary to carry out the reaction under reduced pressure or using an appropriate solvent while removing allyl alcohol produced as a by-product from the reaction system.
A specific method for producing an allyl ester oligomer is described in, for example, Japanese Patent Publication No. 6-74239 (US4959451).

[Curing agent]
A curing agent may be used in the allyl ester resin composition used in the present invention. There is no restriction | limiting in particular as a hardening | curing agent which can be used, What is generally used as a hardening | curing agent of polymeric resin can be used. Among these, it is desirable to add a radical polymerization initiator from the viewpoint of starting polymerization of the allyl group. Examples of the radical polymerization initiator include organic peroxides, photopolymerization initiators, azo compounds and the like.

  As the organic peroxide, known compounds such as dialkyl peroxides, acyl peroxides, hydroperoxides, ketone peroxides, peroxyesters and the like can be used. Specific examples thereof include benzoyl peroxide, 1,1 -Bis (t-butylperoxy) cyclohexane, 2,2-bis (4,4-dibutylperoxycyclohexyl) propane, t-butylperoxy-2-ethylhexanate, 2,5-dimethyl-2,5-di (T-butylperoxy) hexane, 2,5-dimethyl2,5-di (benzoylperoxy) hexane, t-butylperoxybenzoate, t-butylcumyl peroxide, p-methylhydroperoxide, t-butyl Hydroperoxide, cumene hydroperoxide, dicumyl Over peroxide, di -t- butyl peroxide and 2,5-dimethyl-2,5-dibutyl peroxy f relaxin -3, and the like.

  Examples of the photopolymerization initiator include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexyl phenyl ketone, benzophenone, 2-methyl-1- (4-methylthiophenyl)- 2-morpholinopropane-1, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2-hydroxy-2-methyl-1-phenylpropan-1-one and 2,4, Examples include 6-trimethylbenzoyldiphenylphosphine oxide.

  Examples of the azo compound include 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2′-azobis (2 -Methylpropionate), 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis [N- (2-propenyl) ) -2-methylpropionamide], 1-[(1-cyano-1-methylethyl) azo] formamide, 2,2′-azobis (N-butyl-2-methylpropionamide), 2,2′-azobis (N-cyclohexyl-2-methylpropionamide) and the like.

  These radical polymerization initiators may be used alone or in combination of two or more. From the viewpoint of reaction control, it is more preferable to combine two or more kinds of curing agents, a photopolymerization initiator and a thermal polymerization initiator.

  Although there is no restriction | limiting in particular in the compounding quantity of a hardening | curing agent, It is preferable to mix | blend 0.1-10 mass parts with respect to 100 mass parts of radical polymerization components in an allyl ester resin composition, 0.5-5 mass parts combination More preferably. When the blending amount of the curing agent is less than 0.1 parts by mass, it is difficult to obtain a sufficient curing rate. When the blending amount exceeds 10 parts by mass, the final cured product becomes brittle and the mechanical strength decreases. There is a case.

[Reactive monomer]
The allyl ester resin composition used in the present invention contains a reactive monomer (reactive diluent) for the purpose of controlling the curing reaction rate, adjusting the viscosity (improving workability), improving the crosslinking density, and adding functions. It can also be added. There is no restriction | limiting in particular as a reactive monomer, In order to make it react with an allyl ester oligomer, the monomer which has radically polymerizable carbon-carbon double bonds, such as a vinyl group and an allyl group, is preferable. Examples thereof include unsaturated fatty acid esters, aromatic vinyl compounds, vinyl esters of saturated fatty acids or aromatic carboxylic acids and derivatives thereof, crosslinkable polyfunctional monomers, and the like. Especially, if a crosslinkable polyfunctional monomer is used, the crosslinking density of hardened | cured material can also be controlled. Preferred specific examples of these reactive monomers are shown below.

As unsaturated fatty acid ester, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate Alkyl (meth) acrylates such as cyclohexyl (meth) acrylate and methylcyclohexyl (meth) acrylate;
Phenyl (meth) acrylate, benzyl (meth) acrylate, 1-naphthyl (meth) acrylate, fluorophenyl (meth) acrylate, chlorophenyl (meth) acrylate, cyanophenyl (meth) acrylate, methoxyphenyl (meth) acrylate and biphenyl (meth) ) Acrylic acid aromatic esters such as acrylates;
Haloalkyl (meth) acrylates such as fluoromethyl (meth) acrylate and chloromethyl (meth) acrylate;
Furthermore, glycidyl (meth) acrylate, alkylamino (meth) acrylate, α-cyanoacrylic acid ester and the like can be mentioned.

  Examples of the aromatic vinyl compound include styrene, α-methylstyrene, chlorostyrene, styrene sulfonic acid, 4-hydroxystyrene, vinyltoluene and the like.

  Examples of vinyl esters of saturated fatty acids or aromatic carboxylic acids and derivatives thereof include vinyl acetate, vinyl propionate and vinyl benzoate.

As the crosslinkable polyfunctional monomer, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,5-pentadiol di (meth) acrylate, 1,6-hexadiol di (meth) acrylate, neopentyl Glycol di (meth) acrylate, oligoester di (meth) acrylate, polybutadiene di (meth) acrylate, 2,2-bis (4- (meth) acryloyloxyphenyl) propane and 2,2-bis (4-ω- ( Meta) Leroy b carboxymethyl pyridinium) phenyl) di (meth) acrylates such as propane;
Diallyl phthalate, diallyl isophthalate, dimethallyl isophthalate, diallyl terephthalate, triallyl trimellitic acid, diallyl 2,6-naphthalenedicarboxylate, diallyl 1,5-naphthalenedicarboxylate, allyl 1,4-xylenedicarboxylate and 4,4 Difunctional aromatic carboxylates such as diallyl 4'-diphenyldicarboxylate; bifunctional such as diallyl 1,4-cyclohexanedicarboxylate, diallyl 1,2-cyclohexanedicarboxylate, diallyl 1,3-cyclohexanedicarboxylate and divinylbenzene Crosslinkable monomer: trimethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tri (meth) allyl isocyanurate, tri (meth) Trifunctional crosslinkable monomers such as allyl cyanurate, triallyl trimellitate and diallyl chlorendate; and tetrafunctional crosslinkable monomers such as pentaerythritol tetra (meth) acrylate.

  Said reactive monomer can be used individually by 1 type or in mixture or combination of 2 or more types. Although there is no restriction | limiting in particular in the usage-amount of the resin component of these reactive monomers, It is preferable that it is 1-1000 mass parts with respect to 100 mass parts of allyl ester oligomers, and it is more preferable that it is 2-500 mass parts. Preferably, it is 5-100 mass parts. When the amount of the reactive monomer used is less than 1 part by mass, the workability is deteriorated because the effect of reducing the viscosity is small, or when a polyfunctional monomer is used as the reactive monomer, the crosslinking density is lowered and the heat resistance is reduced. May become insufficient. Moreover, when the usage-amount exceeds 1000 mass parts, the outstanding transparency of allyl ester resin itself may not be expressed, or the mechanical strength derived from allyl ester resin may fall.

[Radically reactive resin component]
The allyl ester resin composition used in the present invention may contain a radical reactive resin component for the purpose of improving various physical properties. Examples of these resin components include unsaturated polyester resins and vinyl ester resins.

  Unsaturated polyester resin can be obtained by converting a condensation product obtained by esterification reaction of a polyhydric alcohol and an unsaturated polybasic acid (and a saturated polybasic acid if necessary) into a polymerizable unsaturated compound such as styrene. For example, the resins described in “Polyester Resin Handbook”, published by Nikkan Kogyo Shimbun, 1988, pages 16 to 18, pages 29 to 37, etc. can be mentioned. This unsaturated polyester resin can be produced by a known method.

  Vinyl ester resin, also called epoxy (meth) acrylate, is a ring-opening reaction between a compound having an epoxy group typically represented by an epoxy resin and a carboxyl group of a carboxyl compound having a polymerizable unsaturated group such as (meth) acrylic acid. Polymerized by a ring-opening reaction between a resin having a polymerizable unsaturated group produced by the above, or a compound having a carboxyl group and an epoxy group of a polymerizable unsaturated compound having an epoxy group in the molecule such as glycidyl (meth) acrylate It refers to a resin having a polymerizable unsaturated group. Details are described in “Polyester Resin Handbook”, published by Nikkan Kogyo Shimbun, 1988, pp. 336 to 357, and can be produced by a known method.

  The epoxy resin used as the raw material for the vinyl ester resin includes bisphenol A diglycidyl ether and its high molecular weight homologue, glycidyl ether of bisphenol A alkylene oxide adduct, bisphenol F diglycidyl ether and its high molecular weight homologue, and bisphenol F alkylene oxide. Examples include adduct glycidyl ethers and novolac-type polyglycidyl ethers.

  The above radical-reactive resin components can be used alone or in combination of two or more. Although there is no restriction | limiting in particular in the usage-amount of these radical reactive resin components, It is preferable that it is 1-1000 mass parts with respect to 100 mass parts of allyl ester oligomers, and it is more preferable that it is 2-500 mass parts. Preferably, it is 5-100 mass parts. When the amount of the reactive monomer used is less than 1 part by mass, effects such as improvement in mechanical strength derived from radical-reactive resin components are small, and workability and moldability may be deteriorated. Moreover, when the usage-amount exceeds 1000 mass parts, the heat resistance of allyl ester resin itself may not appear.

[Additive]
In the allyl ester resin composition used in the present invention, for the purpose of improving hardness, strength, moldability, durability, and water resistance, an ultraviolet absorber, an antioxidant, an antifoaming agent, a leveling agent, a release agent, Additives such as lubricants, water repellents, flame retardants, low shrinkage agents, and crosslinking aids can be added as necessary.

  There is no restriction | limiting in particular as antioxidant, What is generally used can be used. Among them, phenolic antioxidants and amine antioxidants that are radical chain inhibitors are preferable, and phenolic antioxidants are particularly preferable. Phenol antioxidants include 2,6-t-butyl-p-cresol, 2,6-t-butyl-4-ethylphenol, 2,2′-methylenebis (4-methyl-6-t-butylphenol) and 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane and the like can be mentioned.

  There is no restriction | limiting in particular as a lubricant, What is generally used can be used. Among these, metal soap lubricants, fatty acid ester lubricants, aliphatic hydrocarbon lubricants and the like are preferable, and metal soap lubricants are particularly preferable. Examples of the metal soap lubricant include barium stearate, calcium stearate, zinc stearate, barium stearate, magnesium stearate, and aluminum stearate. These may be used as a complex.

  There is no restriction | limiting in particular as said ultraviolet absorber, What is generally used can be used. Among these, benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, and cyanoacrylate ultraviolet absorbers are preferable, and benzophenone ultraviolet absorbers are particularly preferable. Examples of benzophenone ultraviolet absorbers include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-5′-butylphenyl) benzotriazole and 2- (2-hydroxy-3). '-T-butylphenyl) benzotriazole and the like.

  These additives are not limited to the specific examples described above, and any additive can be added as long as the object or effect of the present invention is not impaired.

Next, a specific example of the solder heat treatment jig of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing an outline of an example of a solder heat treatment jig of the present invention used in a reflow furnace for mounting by cream solder. Only the window part (2) is made of a heat-resistant transparent resin plate, and the frame part (1) is made of a plate material made of another heat-resistant material (for example, a metal material such as aluminum). This solder heat treatment jig is used in the process of soldering the device by placing it in a heated reflow furnace by placing it on the part where the flux or solder ball splash on the substrate is fixed with cream solder. To do. With this jig, the state of the solder can be observed through the transparent window 2, so that the temperature can be adjusted appropriately.

FIG. 2 is a perspective view (A) of another example of a soldering heat treatment jig according to the present invention and a sectional view showing an outline of a state in which the jig is used on a substrate (4) on which an element (3) is mounted. B).
The solder heat treatment jigs in this example are all made of a heat-resistant transparent resin plate. A notch is provided in a part of the resin plate, and it is assembled into a box shape that divides the elements to be mounted on the board by fitting. It is According to this jig, since the inside can be seen, it can be easily set at an appropriate position. In addition, since the state of the mounting process can be observed from the outside, the heating temperature can be adjusted appropriately to reduce flux and solder splashes. In this example, a box-shaped example is shown, but a jig made only of a resin material is easy to process, and it is possible to create a jig in any shape according to the element and area to be mounted. Thus, the cost can be greatly reduced as compared with the case of using a metal plate.

  3, the basic configuration of the jig is the same as that of FIG. 1 in which the window portion (2) is made of a heat-resistant transparent resin plate and the frame portion (1) is made of a sheet made of another heat-resistant material. In this example, the element (3) to be mounted is set on the substrate (4), and the element (3) is pressed by a spring (5) so that the element (3) is not displaced from the substrate. By covering the periphery with a jig having a transparent resin plate window through which the inside can be observed, it is possible to manufacture a mounted electronic circuit board while confirming that the element (3) is securely pressed. Bonding defect rate can be suppressed.

Although the manufacture example and Example of a transparent resin board are given and demonstrated below, this invention is not limited to the following example.
The physical properties (elastic modulus, thermal shrinkage, pencil hardness, visible light and infrared transmittance) of the transparent resin plate produced in the production example were measured by the following methods.

[Elastic modulus]
The elastic modulus was measured according to ASTM D790, which is a standard for flexural modulus.

[Heat shrinkage]
It measured based on JIS C-2151. The heating time temperature was 200 ° C. for 30 minutes.

[Pencil hardness]
The pencil hardness was measured at 750 g based on JIS K5600-5-4.

[Transmissivity of visible light and infrared light]
The total transmittance in the visible light region (380 to 780 nm) and the total transmittance in the infrared region (780 to 2500 nm) were measured using an ultraviolet-visible-near infrared spectrophotometer (V-570 manufactured by JASCO Corporation). .

Production Example 1:
B A 2-liter three-necked flask equipped with a distillation apparatus was charged with 1625 g of diallyl terephthalate, 167 g of propylene glycol and 0.813 g of dibutyltin oxide, and heated while distilling off the alcohol produced at 180 ° C. in a nitrogen stream. did. When the distilled alcohol reached about 170 g, the pressure in the reaction system was gradually reduced to 6.6 kPa over about 4 hours to increase the alcohol distillation rate. When the distillate almost disappeared, the pressure in the reaction system was reduced to 0.5 kPa and the reaction was further continued for 1 hour, and then the reaction product was cooled. Hereinafter, the reaction product thus obtained is referred to as “allyl ester oligomer (1)”.
To 100 parts by mass of the prepared allyl ester oligomer (1), 10 parts by mass of pentaerythritol tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., “NK Ester A-TMMT”), photoinitiator (manufactured by Ciba Specialty Chemicals) , “DAROCUR MBF”) and 1 part by mass of a thermal initiator (manufactured by NOF Corporation, “Perhexyl I”) were added and sufficiently stirred to obtain an allyl ester resin composition (2). This composition (2) was applied on a glass substrate with a bar coater so as to have a thickness of 0.5 mm, and UV (Eye Graphics Co., Ltd. ECS-4011GX-S, using a metal halide lamp) was applied at a dose of 1200 mJ / cm ² . After UV curing, the film was completely cured by heat treatment at 160 ° C. for 1 hour in an oven to prepare an allyl ester resin plate (1) having a thickness of 0.5 mm.
The allyl ester resin plate (1) has a normal temperature (20 ° C.) elastic modulus of 2.8 GPa, a thermal shrinkage of less than 0.1%, a pencil hardness of 3H, a visible light transmittance of 90% or more, and an infrared transmittance of 60. % Or more.

Production Example 2:
An allyl ester resin plate (2) having a thickness of 0.3 mm was produced in the same manner as in Production Example 1, except that the thickness was applied to a thickness of 0.3 mm with a bar coater.
The allyl ester resin plate (2) has a normal temperature (20 ° C.) elastic modulus of 2.8 GPa, a heat shrinkage rate of less than 0.1%, a pencil hardness of 3H, a visible light transmittance of 90% or more, and an infrared transmittance of 60. % Or more.

Example 1:
A solder heat treatment jig shown in FIG. 1 was used as a reflow furnace jig for mounting with cream solder. The material of the frame part (1) of the jig is an aluminum plate having a thickness of 1 mm. The 0.5 mm thick sheet produced in Production Example 1 was used for the transparent window part (2). The jig was placed on a part where the flux on the substrate, on which the element was fixed with cream solder, or splashing of the solder ball became a problem, and was transported in a reflow furnace heated to about 220 ° C., and the element was soldered. Flux and solder splashes were reduced, and the defect rate could be greatly reduced. The state of the internal solder could be observed through a transparent window, and the temperature could be adjusted appropriately. As a result, the defect rate could be reduced by 20%. In addition, since the jig is lightweight, the entire board can be mounted uniformly without adversely affecting the board. Also, the substrate transfer in the furnace could be carried out without any modification of the equipment.
The surface of the jig was soiled by flux or solder, but could be used repeatedly by washing with a solvent such as IPA or acetone. The jig was used repeatedly over 1000 times, but no quality problems occurred.

Example 2:
As a reflow furnace jig for mounting with cream solder, a built-in box-type solder heat treatment jig shown in FIG. 2 composed only of the allyl ester resin plate (2) of Production Example 2 was used. The solder heat treatment jig made of an allyl ester resin plate having a thickness of 0.3 mm was mounted around an element having a particularly high defect rate. Since the inside can be seen, it has become possible to set it in an appropriate position. In addition, since the mounting state can be observed from the outside, mounting can be performed without excessive application of temperature, and flux and solder droplets can be reduced. Moreover, the thickness of the sheet was as thin as 0.3 mm, and the jig shown in FIG. 2 could be efficiently installed in a narrow space between the elements.
After use, as in Example 1, it was washed with IPA, acetone, etc. and used repeatedly, but there was no problem in the service life.

Example 3:
Using the same sheet as in Example 1, a solder heat treatment jig shown in FIG. 3 was produced. The element to be mounted was set on the substrate, and the element was held by a spring 5 so that the element was not displaced from the substrate. By covering the periphery with a transparent resin plate, it was confirmed that the element was reliably pressed, and solder joint failure could be greatly suppressed. The defect rate was reduced by about 25% compared to the case where no solder heat treatment jig was used.
After use, as in Example 1, it was washed with IPA, acetone, etc. and repeatedly used, but there was no problem with the soldering heat treatment jig.

1: Jig frame portion 2: Window portion of transparent heat-resistant resin plate 3: Element 4: Substrate 5: Pressing spring 6: Jig base material

Claims (7)

A jig (solder for heat treatment of solder) used in a process of mounting an element by reflowing solder on a board to prevent adhesion of solder droplets to the board due to bumping of flux. There is no opening other than the bottom surface in contact with the substrate, and all or a part thereof is formed of a heat-resistant transparent resin plate. The heat-resistant transparent resin plate has a thermal shrinkage rate at 200 ° C. relative to normal temperature (20 ° C.) of 0. It is made of a thermosetting resin that is 5% or less, and the thermosetting resin is represented by the following general formula (2)
(Wherein R ³ represents a hydrogen atom or a methyl group, and A ² represents one or more organic residues having an alicyclic structure and / or an aromatic ring structure derived from dicarboxylic acid.)
And a group represented by the following general formula (3)
(In the formula, A ³ represents one or more organic residues having an alicyclic structure and / or an aromatic ring structure derived from dicarboxylic acid, and X represents ethylene glycol, propylene glycol, 1,3-propanediol, 1 , 3-butanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, hexamethylene glycol , 1,4-cyclohexanedimethanol, 2-methyl-1,3-propanediol, 3-methyl -1,5-pentanediol, diethylene glycol, dipropylene glycol, triethylene glycol, polyethylene glycol, bisphenol-A ethylene oxide adduct, bisphenol-A propylene oxide adduct, hydrogenated bisphenol A, 2,2- [4 -(2-hydroxyethoxy) -3 5-dibromophenyl] propane, represents glycerin, trimethylolpropane, trimethylolethane, one or more organic residues derived from pentaerythritol or dipenta et Risuritoru. However, X is the formula by ester bonds (2) (A branched structure having the structure represented by the general formula (3) as a structural unit can be formed.)
A solder heat treatment jig, which is an allyl ester resin that is a cured product of an allyl ester resin composition mainly composed of an allyl ester oligomer having a structure represented by   The jig for solder heat treatment according to claim 1, wherein at least a window portion is formed of the heat-resistant transparent resin plate.   The jig for solder heat treatment according to claim 1 or 2, wherein the heat-resistant transparent resin plate has an elastic modulus of 2.5 to 3.5 GPa.   The jig for solder heat treatment according to claim 1, wherein the heat-resistant transparent resin plate has a surface hardness of pencil hardness H or more.   5. The solder heat treatment jig according to claim 1, wherein the heat-resistant transparent resin plate has a visible light transmittance of 85% or more and an infrared transmittance of 50% or more.   The jig for solder heat treatment according to any one of claims 1 to 5, wherein the heat-resistant transparent resin plate has a thickness of 0.1 mm or more and 1.5 mm or less.   An element is brought into contact with the conductive circuit on the substrate via cream solder, the element is covered with the solder heat treatment jig according to any one of claims 1 to 6, and the cream solder is reflowed in a heating furnace, A method of manufacturing a mounted electronic circuit board, comprising electrically connecting a conductive circuit and an element.