JP2014060368A - Manufacturing method of mold for solder ball manufacturing and solder ball manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a mold for solder ball manufacturing which can manufacture fine solder balls having uniform particle sizes of 70 μm and under, and which can manufacture easily and in a short time, a mold for solder ball manufacturing which is capable of easily releasing the manufactured solder ball from the mold; and provide a solder ball manufacturing method using the mold for solder ball manufacturing manufactured by the above-described method.SOLUTION: A manufacturing method of a mold for solder ball manufacturing comprises: forming recesses each having a hemispherical shape on a substrate by using a resin pattern which is formed on the substrate by a photolithography method and has circular openings each having a predetermined diameter as a mask; forming after removing the resin pattern, a mold release film composed of a specific material on a substrate of the substrate on which the recesses are formed.

Description

  The present invention relates to a method for manufacturing a mold for manufacturing solder balls, and a method for manufacturing solder balls.

  Along with miniaturization of LSIs and LSI packages as electrical and electronic devices such as mobile phones become smaller and more sophisticated, the pitch between terminals is reduced in order to connect them with high precision on the board. There is a demand for miniaturization of solder bumps provided on substrates and terminals.

  As a method of manufacturing a fine solder ball for forming a fine solder bump, for example, by applying vibration to the molten solder in a crucible, a solder droplet having a uniform volume is sprayed from the crucible, and the droplet is sprayed. A method for producing solder balls by solidification (Patent Document 1) or a method for forming a recess on a substrate such as a stainless steel plate by a method such as electric discharge machining, filling the recess with the solder paste, and then filling the recess. A method of manufacturing solder balls by heating the solder to make it spherical (Patent Document 2) is known.

JP 2009-034692 A Japanese Patent No. 3305162

  As for various semiconductor chips and the like, various pitches of terminals are further narrowed along with miniaturization and high performance of various electric / electronic devices. For this reason, further miniaturization is required for the solder balls used for forming solder bumps on the terminals of the semiconductor chip and on the surface of the substrate, for example, the particle diameter is 70 μm or less. However, in the methods described in Patent Documents 1 and 2, it is not easy to produce fine solder balls having a particle diameter of 70 μm or less.

  In the method described in Patent Document 1, the diameter of the solder ball to be obtained is determined by the viscosity and surface tension of the molten solder, the diameter of the discharge port that discharges the molten solder, and the like. The cause is the diameter of the discharge port. For this reason, in order to reduce the size of the solder balls, it is necessary to reduce the diameter of the discharge port that discharges the molten solder. However, because of the need to discharge the molten solder well, it is necessary to reduce the diameter of the discharge port. There are limits. Therefore, with the method described in Patent Document 1, it is difficult to further miniaturize the solder balls.

  Further, in the method described in Patent Document 2, since depressions are formed on the substrate surface by a method such as electric discharge machining, a large number of fine and uniform depressions may be formed on the substrate due to the problem of machining accuracy. difficult. Furthermore, in the method described in Patent Document 2, when a solder ball is manufactured using a substrate having a depression formed as a mold, the manufactured solder ball may be difficult to release from the mold.

  The present invention has been made in view of the above-described problems, and can produce fine solder balls having a uniform particle diameter and a particle diameter of 70 μm or less. An object of the present invention is to provide a method for producing a mold for producing solder balls, which can easily produce a mold for producing solder balls that can be released in a short time. Another object of the present invention is to provide a solder ball manufacturing method using the solder ball manufacturing mold manufactured by the above-described method.

  The present inventors formed a substantially hemispherical recess on the substrate using a resin pattern having a circular opening of a predetermined diameter formed on the substrate by a photolithography method, and after peeling the resin pattern, It has been found that the above problem can be solved by forming a mold for solder ball production by forming a release film made of a specific material on the surface of the substrate on which the recess is formed, and has completed the present invention. Specifically, the present invention provides the following.

The first aspect of the present invention is:
Forming a photosensitive resin layer on the substrate surface, a photosensitive resin layer forming step;
A resin pattern forming step of exposing and developing the photosensitive resin layer to form a resin pattern having a circular opening of one or more predetermined diameters on the substrate;
Forming a substantially hemispherical recess on the surface of the substrate exposed from the circular opening on the resin pattern; and
A resin pattern peeling step for peeling the resin pattern;
A release film forming step of covering the inner surface of the recess and another substrate surface of the inner surface of the recess, and forming a release film having lower wettability with respect to the solder than the substrate surface;
A method for producing a mold for producing solder balls.

The second aspect of the present invention is:
A solder filling step of filling the recesses on the mold for producing solder balls produced by the method according to the first aspect with solder;
A solder spheronization process in which the solder filled in the recesses is placed under a temperature equal to or higher than the melting point of the solder to spheroidize the solder;
A method for producing solder balls including:

  According to the present invention, it is possible to produce a fine solder ball having a uniform particle size and a particle size of 70 μm or less, and a mold for producing a solder ball capable of easily releasing the manufactured solder ball. Can be easily produced in a short time, and a method for producing a mold for producing solder balls can be provided. Moreover, this invention can provide the manufacturing method of a solder ball using the mold for solder ball manufacturing manufactured by the above-mentioned method.

It is a figure which shows the outline of the manufacturing method of the mold for solder ball manufacture which concerns on the 1st aspect of this invention. It is a figure which shows the outline of the manufacturing method of the mold for solder ball manufacture which concerns on the 2nd aspect of this invention.

[First aspect]
The first aspect of the present invention is:
Forming a photosensitive resin layer on the substrate surface, a photosensitive resin layer forming step;
A resin pattern forming step of exposing and developing the photosensitive resin layer, the photosensitive resin layer, and forming a resin pattern having a circular opening of one or more predetermined diameters on the substrate;
Forming a substantially hemispherical recess on the surface of the substrate exposed from the circular opening on the resin pattern; and
A resin pattern peeling step for peeling the resin pattern;
A mold release film forming step of coating the inner surface of the recess and the other substrate surface of the inner surface of the recess, and forming a release film having lower wettability with respect to the solder than the substrate surface;
A method for producing a mold for producing solder balls.

  Further, in the method for manufacturing a mold for producing solder balls according to the first aspect of the present invention, when the recess formed on the substrate is formed by sandblasting, wet etching is performed on the inner surface of the recess. It is preferred to do so. Hereafter, with reference to FIG. 1, each process included in the manufacturing method of the mold for solder ball manufacture which concerns on a 1st aspect is demonstrated.

[Photosensitive resin layer forming step]
As shown in FIG. 1A and FIG. 1B, in the photosensitive resin layer forming step, a resin pattern 15 that is a mask for forming the recesses 17 is formed on the surface of the substrate 10. A photosensitive resin layer 11 is formed. The resin pattern 15 is formed by exposing and developing the photosensitive resin layer 11. The material of the photosensitive resin layer (hereinafter also referred to as a photosensitive resin composition) is not particularly limited as long as the resin pattern 15 having a strength that can withstand the treatment for forming the recesses 17 can be formed. The photosensitive resin composition may be negative or positive as long as the predetermined resin pattern 15 can be formed.

  The material of the board | substrate 10 will not be specifically limited if the recessed part 17 can be formed in the recessed part formation process mentioned later, and it is a material which does not produce deterioration and deformation | transformation by a heat | fever under the temperature which melt | dissolves a solder. Suitable substrate materials include glass, epoxy resin and polyimide. Among these materials, glass is preferable because of excellent heat resistance and excellent workability when forming the recesses 17.

  The photosensitive resin contained in the photosensitive resin composition is not particularly limited as long as the object of the present invention is not impaired. As a process for forming the concave portion 17 in the concave portion forming step to be described later, a sand blast method is preferable. In the case where the concave portion 17 is formed and slid by the sandblasting method, the photosensitive resin contained in the photosensitive resin composition is composed of a cellulose resin, an acrylic resin, and a resin having a urethane bond, from the viewpoint of the sandblast resistance of the resin pattern 15. Preferably, a resin having a urethane bond is more preferable.

  The photosensitive resin composition includes a photopolymerization initiator, a photopolymerizable compound, a light depending on the type of the photosensitive resin contained in the photosensitive resin composition and the mode of exposure and development processes for the photosensitive resin layer 11. Various components conventionally blended in the photosensitive resin composition, such as a polymerization initiator, a sensitizer, a polymerization inhibitor, and a plasticizer, may be included.

  The photosensitive resin layer 11 may be formed by applying a liquid photosensitive resin composition containing a solvent to the surface of the substrate 10. Alternatively, the photosensitive resin layer 11 may be formed by applying a liquid photosensitive resin composition on a release film and then drying to form a dry film and then affixing it to the surface of the object to be processed. The film thickness of the photosensitive resin layer 11 is appropriately adjusted according to the film thickness of the resin pattern 15 to be formed. The film thickness of the resin pattern 15 will be described later.

  Examples of the solvent that can be used for preparing the liquid photosensitive resin composition include halogenated hydrocarbons such as chloroform and tetrachloroethylene; ethers such as dibutyl ether, isopropyl ether, dioxane, and tetrahydrofuran; acetone, diethyl ketone, Ketones such as methyl ethyl ketone, methyl isobutyl ketone, methyl propyl ketone, and cyclohexanone; esters such as ethyl acetate, n-propyl acetate, and n-butyl acetate; aromatic hydrocarbons such as benzene, toluene, and xylene An organic solvent is mentioned.

[Resin pattern forming process]
As shown in FIG. 1B to FIG. 1E, in the resin pattern forming step, the photosensitive resin layer 11 formed in the photosensitive resin layer forming step is interposed through a mask 12 having a predetermined pattern. After the light beam 13 is irradiated for exposure, the exposed photosensitive resin layer 11 is developed with a developer 14 to form a resin pattern 15 having a circular opening 16 having a predetermined diameter. The resin pattern 15 is used as a mask when the concave portion 17 is formed on the substrate.

  The exposure means for irradiating the photosensitive resin layer 11 with the light beam 13 is not particularly limited, and for example, a low pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, an argon gas laser, or the like can be used.

  The developing method after exposure is not particularly limited as long as the resin pattern 15 having a desired shape can be formed. When the resin pattern is insoluble in alkali and the portion removed by development is soluble in alkali, an alkaline aqueous solution can be used as the developer 14. For example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanol Amines, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo [5,4,0] -7-undecene, and 1,5-diazabicyclo [4,3,0] -5 An aqueous solution of an alkali such as nonane can be used. Further, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant to the alkaline aqueous solution may be used as the developer 14.

  Further, when the resin pattern is insoluble in the organic solvent and the portion to be removed by development is soluble in the organic solvent, the developer 14 containing the organic solvent can be used. In this case, the organic solvent contained in the developer 14 is appropriately selected from organic solvents that have been conventionally used in developers in photolithography.

  The development time is not particularly limited, and is usually 1 to 30 minutes. Examples of the developing method include a liquid piling method, a dipping method, a paddle method, and a spray developing method. After development, post-baking may be performed after washing and rinsing as necessary.

  The diameter of the circular opening 16 formed in the resin pattern 15 is determined according to the diameter of the opening of the recess 17 formed in the mold for producing solder balls. The diameter of the opening of the recess 17 will be described later.

  The thickness of the resin pattern 15 is not particularly limited as long as the resin pattern 15 can withstand a process for forming the concave portion 17 such as a sandblast process. The thickness of the resin pattern 15 is typically preferably 10 to 100 μm, and more preferably 20 to 60 μm.

(Recess formation process)
As shown in FIG. 1E to FIG. 1F, in the recess forming step, the resin pattern 15 formed on the substrate 10 by the resin pattern forming step is used as a mask, and the surface of the substrate 10 is 1 The above substantially hemispherical concave portion 17 is formed.

  The treatment for forming the recess 17 is not particularly limited as long as the object of the present invention is not impaired. Suitable methods for forming the recesses 17 using the resin pattern 15 formed on the substrate 10 as a mask include a sand blast method, a wet etching method, a dry etching method, and the like. Among these processing methods, the sandblasting method is preferable because the concave portion 17 having a predetermined shape can be formed in a short time. Hereinafter, the sandblast method will be described.

The conditions for the sandblasting treatment are not particularly limited as long as the concave portion 17 having a predetermined shape can be formed. The type of blasting material used for the sandblasting process is not particularly limited as long as the substrate can be ground, and is appropriately selected according to the material of the substrate. Examples of suitable blast materials include glass beads, alumina particles, silica particles, silicon carbide particles, and zirconium oxide particles. The particle size of the blast material is not particularly limited as long as the concave portion 17 having a predetermined shape can be formed. The average particle size of the blast material is typically preferably 5 to 90 μm, and more preferably 15 to 60 μm. Further, the blasting pressure is typically preferably ^{0.3~1.0kg / cm 2 (G),} 0.4~0.7kg / cm 2 (G) is more preferable.

  The diameter of the opening portion of the substantially hemispherical concave portion 17 formed on the substrate 10 by the sandblasting process is not particularly limited, and in consideration of the thickness of the release film 19 formed on the surface of the concave portion 17, It is determined appropriately according to the size of the solder ball formed using the solder ball manufacturing mold obtained by the method according to the embodiment. 10-100 micrometers is preferable and the diameter of the opening part of the recessed part 17 has more preferable 20-60 micrometers. By making the diameter of the opening of the recess 17 in such a range, when manufacturing the solder ball according to the second aspect of the present invention, it is easy to manufacture a solder ball having a diameter of 70 μm or less. Further, the depth of the recess 17 is preferably 0.3 to 0.7 times the diameter of the recess 17, and more preferably 0.4 to 0.6 times.

[Resin pattern peeling process]
As shown in FIGS. 1 (f) to 1 (h), a substantially hemispherical concave portion 17 having a predetermined shape is formed on the surface of the substrate 10 by the concave portion forming step, and then the surface of the substrate 10 is removed by the resin pattern peeling step. The resin pattern 15 is peeled off. The method of peeling the resin pattern 15 is not particularly limited. However, the resin pattern 15 is made of resin by using a peeling liquid (cleaning liquid) 18 because the peeling work is easy and the residue of the resin pattern 15 hardly remains in the recess 17 after peeling. A method of peeling the pattern 15 is preferable.

  The stripping solution 18 is not particularly limited as long as the resin pattern 15 can be stripped, and is appropriately selected from stripping solutions conventionally used for stripping photosensitive resin compositions. Examples of the stripper 18 include organic solvent strippers, amines such as monoethanolamine, diethanolamine, and triethanolamine; quaternary ammonium hydroxides such as tetramethylammonium hydroxide; sodium hydroxide, hydroxide Examples include basic alkali metal compounds such as potassium and sodium carbonate; and basic stripping solutions containing a base such as ammonia. The solvent contained in the basic stripping solution is appropriately selected from water, an organic solvent, and an organic solvent aqueous solution.

  The method for peeling the resin pattern 15 with the peeling liquid 18 is not particularly limited. Examples of the peeling of the resin pattern with the peeling liquid include a liquid piling method, a dipping method, a paddle method, and a spray method.

[Wet etching process]
In the method for manufacturing a mold for producing solder balls according to the first aspect, when the concave portion 17 is formed by sand blasting, it is preferable that the surface of the concave portion 17 on the substrate formed by sand blasting is wet-etched. Since the surface of the recess 17 formed by sandblasting is in a rough state, when the solder ball is manufactured using the mold 1, the solder ball may be slightly difficult to release from the mold 1. However, when the surface of the recess 15 is wet-etched, the surface of the recess 15 becomes smooth, so that the releasability of the solder ball when manufacturing the solder ball using the mold 1 can be greatly improved.

  The wet etching may be performed at any stage before and after the resin pattern peeling step, and is preferably performed after the resin pattern peeling step. The wet etching method is not particularly limited as long as the surface of the recess 15 can be made smooth, and is appropriately selected from known etching methods according to the material of the substrate.

  As a suitable etching method when the substrate is made of glass, a wet etching method using hydrofluoric acid can be used.

[Release film forming process]
As shown in FIG. 1 (h) and FIG. 1 (i), in the release film forming step, the inner surface of the concave portion 17 and the surface of another substrate 10 on the inner surface of the concave portion 17 are covered to form a substrate. A release film 19 having a lower wettability with respect to solder than the surface 10 is formed. The thickness of the release coating 19 is preferably substantially uniform.

  When producing solder balls using the mold for producing solder balls produced by the method according to the first aspect, the solder balls formed in the recesses 17 in the mold 1 are peeled off from the mold 1 and solder balls are produced. However, by providing the mold 1 with the release film 19, the ease of peeling of the solder balls from the surface of the mold 1 is remarkably improved. For this reason, when manufacturing a solder ball using the mold for manufacturing a solder ball according to the first aspect, the solder ball can be manufactured with high efficiency. Moreover, the diameter of the opening part of the recessed part 17 can be easily adjusted by forming the release film 19 of a predetermined thickness on the surface of the recessed part 17. For this reason, according to the method for manufacturing a mold for manufacturing solder balls according to the first aspect, it is possible to easily manufacture the mold 1 for manufacturing solder balls including the concave portions 17 having a uniform and minute size.

  The thickness of the release film 19 is not particularly limited as long as the concave portion 17 having a predetermined shape can be formed. The thickness of the release film 19 is typically preferably 0.1 to 2.0 μm, and more preferably 0.5 to 1.5 μm.

  The material of the release film 19 is not particularly limited as long as the material has lower wettability with respect to the solder than the material of the substrate 10, and is appropriately selected according to the material of the substrate 10. Suitable release film 19 materials include, for example, cobalt, nickel, tungsten, molybdenum, aluminum, chromium, titanium, iron, zinc, and alloys of these metals; chromates; phosphates; spin-on-glass (SOG) materials. One or more materials selected from the group consisting of: The method of forming the release film 19 on the substrate 10 is not particularly limited as long as the release film 19 can be formed with a desired film thickness, and is appropriately selected from methods such as a thermal spraying method, a PVD method, a CVD method, and a coating method. The Among these materials, a spion glass (SOG) material is more preferable because it is easy to control the film thickness of the release film 19 and to form the release film 19.

  The spin-on-glass (SOG) material can be appropriately selected from those conventionally used for various applications. The spion glass (SOG) material is preferably formed by applying a solution containing a precursor of the spion glass (SOG) material to the surface of the substrate 10. The spion glass (SOG) material is obtained, for example, by hydrolyzing at least one selected from alkoxysilanes represented by the following general formula (I), which is a precursor of the spion glass (SOG) material, as a siloxane polymer. Reaction products are preferred.

R _4-n Si (OR ′) _n (I)
(In the formula (I), R represents a hydrogen atom, an alkyl group or a phenyl group, R ′ represents an alkyl group or a phenyl group, and n represents an integer of 2 to 4. A plurality of R are bonded to Si. And the plurality of R may be the same or different, and the plurality of (OR ′) groups bonded to Si may be the same or different.

  When R is an alkyl group, a linear or branched alkyl group having 1 to 20 carbon atoms is preferable, and a linear or branched alkyl group having 1 to 4 carbon atoms is more preferable. At least one of R is an alkyl group or a phenyl group.

  When R ′ is an alkyl group, a linear or branched alkyl group having 1 to 5 carbon atoms is preferable. When R 'is an alkyl group, the carbon number is preferably 1 or 2 from the viewpoint of hydrolysis rate.

  The reaction product obtained by hydrolyzing the alkoxysilane represented by the above formula (I) is produced by producing a low molecular weight hydrolyzate or a dehydration condensation reaction between molecules simultaneously with the hydrolysis reaction. Siloxane oligomers may be included. In this specification, when a siloxane polymer contains such a low molecular weight hydrolyzate or siloxane oligomer, the siloxane polymer indicates the whole including these.

  The mass average molecular weight (Mw) of the siloxane polymer (polystyrene conversion standard by gel permeation chromatography, the same applies hereinafter) is preferably 1000 to 3000, more preferably 1200 to 2700, and particularly preferably 1500 to 2000.

The silane compound (i) when n in the general formula (I) is 4 is represented by the following general formula (II).
Si (OR ¹ ) _a (OR ² ) _b (OR ³ ) _c (OR ⁴ ) _d (II)
(In formula (II), R ¹ , R ² , R ³ and R ⁴ each independently represents an alkyl group or a phenyl group. A, b, c and d are each independently an integer of 0 to 4. , A, b, c and d is 4.)

Suitable alkyl groups as R ¹ , R ² , R ³ and R ^{4 are the same} as R ′ in formula (I).

The silane compound (ii) when n in the general formula (I) is 3 is represented by the following general formula (III).
R ⁵ Si (OR ⁶ ) _e (OR ⁷ ) _f (OR ⁸ ) _g (III)
(In Formula (III), R ⁵ represents a hydrogen atom, an alkyl group, or a phenyl group. R ⁶ , R ⁷ , and R ⁸ each independently represents an alkyl group or a phenyl group. E, f, and g) Are each independently an integer of 0 to 3, and the sum of e, f and g is 3.)

Suitable alkyl groups for R ^{5 are the same} as R in formula (I). Also, suitable alkyl groups as R ⁶ , R ⁷ and R ^{8 are the same} as R ′ in formula (I).

The silane compound (iii) when n in the general formula (I) is 2 is represented by the following general formula (IV).
R ⁹ R ¹⁰ Si (OR ¹¹ ) _h (OR ¹² ) _i (IV)
(In formula (IV), R ⁹ and R ¹⁰ represent a hydrogen atom, an alkyl group, or a phenyl group, provided that at least one of R ⁹ and R ¹⁰ represents an alkyl group or a phenyl group. R ¹¹ , And R ¹² each independently represents an alkyl group or a phenyl group, h and i are each independently an integer of 0 to 2, and the sum of h and i is 2.)

Suitable alkyl groups for R ⁹ and R ^{10 are the same} as R in formula (I). Also, suitable alkyl groups for R ¹¹ and R ^{12 are the same} as R ′ in formula (I).

  Specific examples of the silane compound (i) include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, tetrapentyloxysilane, tetraphenyloxysilane, trimethoxymonoethoxysilane, dimethoxydiethoxysilane, and triethoxy. Monomethoxysilane, trimethoxymonopropoxysilane, monomethoxytributoxysilane, monomethoxytripentyloxysilane, monomethoxytriphenyloxysilane, dimethoxydipropoxysilane, tripropoxymonomethoxysilane, trimethoxymonobutoxysilane, dimethoxydibutoxy Silane, triethoxymonopropoxysilane, diethoxydipropoxysilane, tributoxymonopropoxysilane, dimethoxymonoethoxymonobutyl Xysilane, diethoxymonomethoxymonobutoxysilane, diethoxymonopropoxymonobutoxysilane, dipropoxymonomethoxymonoethoxysilane, dipropoxymonomethoxymonobutoxysilane, dipropoxymonoethoxymonobutoxysilane, dibutoxymonomethoxymonoethoxysilane, Examples include tetraalkoxysilanes such as dibutoxymonoethoxymonopropoxysilane and monomethoxymonoethoxymonopropoxymonobutoxysilane. Of these tetraalkoxysilanes, tetramethoxysilane and tetraethoxysilane are preferable.

  Specific examples of the silane compound (ii) include methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltripentyloxysilane, ethyltrimethoxysilane, ethyltripropoxysilane, ethyltripentyloxysilane, ethyltripentylsilane. Phenyloxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltripentyloxysilane, propyltriphenyloxysilane, butyltrimethoxysilane, butyltriethoxysilane, butyltripropoxysilane, butyltripentyloxysilane, butyltriphenyl Oxysilane, methylmonomethoxydiethoxysilane, ethylmonomethoxydiethoxysilane, propylmonomethoxydiethoxysilane, butylmonomethoxydi Toxisilane, Methylmonomethoxydipropoxysilane, Methylmonomethoxydipentyloxysilane, Methylmonomethoxydiphenyloxysilane, Ethylmonomethoxydipropoxysilane, Ethylmonomethoxydipentyloxysilane, Ethylmonomethoxydiphenyloxysilane, Propylmonomethoxydipropoxysilane , Propylmonomethoxydipentyloxysilane, propylmonomethoxydiphenyloxysilane, butylmonomethoxydipropoxysilane, butylmonomethoxydipentyloxysilane, butylmonomethoxydiphenyloxysilane, methylmethoxyethoxypropoxysilane, propylmethoxyethoxypropoxysilane, butylmethoxy Ethoxypropoxysilane, methyl monomethoxy monoethoxy mono Tokishishiran, ethyl monomethoxy Monoethoxy monobutoxy silane, propyl monomethoxy Monoethoxy monobutoxy silane, and monoalkyl trialkoxysilane, such as butyl monomethoxy Monoethoxy monobutoxy silane and the like. Among the monoalkyltrialkoxysilanes, methyltrialkoxysilane is preferable, and methyltrimethoxysilane and methyltriethoxysilane are particularly preferable.

  Specific examples of the silane compound (iii) include methyldimethoxysilane, methylmethoxyethoxysilane, methyldiethoxysilane, methylmethoxypropoxysilane, methylmethoxypentyloxysilane, methylmethoxyphenyloxysilane, ethyldipropoxysilane, ethylmethoxypropoxy. Silane, ethyldipentyloxysilane, ethyldiphenyloxysilane, propyldimethoxysilane, propylmethoxyethoxysilane, propylethoxypropoxysilane, propyldiethoxysilane, propyldipentyloxysilane, propyldiphenyloxysilane, butyldimethoxysilane, butylmethoxyethoxysilane, Butyldiethoxysilane, Butylethoxypropoxysilane, Butyldipropoxysilane, Butyl Tildipentyloxysilane, butylmethyldiphenyloxysilane, dimethyldimethoxysilane, dimethylmethoxyethoxysilane, dimethyldiethoxysilane, dimethyldipentyloxysilane, dimethyldiphenyloxysilane, dimethylethoxypropoxysilane, dimethyldipropoxysilane, diethyldimethoxysilane, diethyl Methoxypropoxysilane, diethyldiethoxysilane, diethylethoxypropoxysilane, dipropyldimethoxysilane, dipropyldiethoxysilane, dipropyldipentyloxysilane, dipropyldiphenyloxysilane, dibutyldimethoxysilane, dibutyldiethoxysilane, dibutyldipropoxysilane , Dibutylmethoxypentyloxysilane, dibutylmethoxyphenyloxy Silane, methylethyldimethoxysilane, methylethyldiethoxysilane, methylethyldipropoxysilane, methylethyldipentyloxysilane, methylethyldiphenyloxysilane, methylpropyldimethoxysilane, methylpropyldiethoxysilane, methylbutyldimethoxysilane, methylbutyldi Ethoxysilane, methylbutyldipropoxysilane, methylethylethoxypropoxysilane, ethylpropyldimethoxysilane, ethylpropylmethoxyethoxysilane, dipropyldimethoxysilane, dipropylmethoxyethoxysilane, propylbutyldimethoxysilane, propylbutyldiethoxysilane, dibutylmethoxy Ethoxysilane, dibutylmethoxypropoxysilane, dibutylethoxypropoxysilane, etc. And dialkyl dialkoxysilane. Among these dialkyl dialkoxysilanes, methyldimethoxysilane and methyldiethoxysilane are preferable.

The silane compound used as the precursor of the siloxane polymer contained in the spion glass (SOG) material can be appropriately selected from the silane compounds (i) to (iii). As the silane compound, the silane compound (i) is most preferable. When these silane compounds are used in combination, a more preferred combination is a combination of silane compound (i) and silane compound (ii). In the case of using the silane compound (i) and the silane compound (ii), the use ratio thereof is preferably in the range of 10 to 60 mol% of the silane compound (i) and 90 to 40 mol% of the silane compound (ii). The silane compound (i) is more preferably in the range of 15 to 50 mol% and the silane compound (ii) in the range of 85 to 50 mol%. The silane compound (ii) is preferably a compound in which R ⁵ in the general formula (III) is an alkyl group or a phenyl group, and more preferably a compound in which R ⁵ is an alkyl group.

  The siloxane polymer contained in the spion glass (SOG) material is, for example, a hydrolysis or condensation reaction of one or more selected from the silane compounds (i) to (iii) in the presence of an acid catalyst, water, and an organic solvent. It can be prepared by a caulking method.

The acid catalyst may be either an organic acid or an inorganic acid. As the inorganic acid, sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid and the like can be used, among which phosphoric acid and nitric acid are preferable. As the organic acid, formic acid, oxalic acid, fumaric acid, maleic acid, glacial acetic acid, acetic anhydride, propionic acid, carboxylic acids such as n-butyric acid, and organic acids having a sulfur-containing acid residue are used. Examples of the organic acid having a sulfur-containing acid residue include organic sulfonic acids, organic sulfates, and organic sulfites. Among these organic acids, for example, an organic sulfonic acid compound represented by the following general formula (V) is preferable.
R ¹³ -Z (V)
(In the formula, R ¹³ is a hydrocarbon group which may have a substituent, and Z is a sulfonic acid group.)

In the general formula (V), R ¹³ is preferably a hydrocarbon group having 1 to 20 carbon atoms. When R ¹³ is a hydrocarbon group, the hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, and the structure of the hydrocarbon group is linear, branched, cyclic, And any combination of these structures. When R ¹³ is a cyclic hydrocarbon group, for example, an aromatic hydrocarbon group such as a phenyl group, a naphthyl group, and an anthryl group is preferable, and a phenyl group is more preferable.

When R ¹³ is an aromatic hydrocarbon group, one or more hydrocarbon groups having 1 to 20 carbon atoms may be bonded to the aromatic ring in the hydrocarbon group as a substituent. The hydrocarbon group as a substituent on the aromatic ring may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. Further, the hydrocarbon group as R ¹³ may have one or a plurality of substituents. Examples of the substituent that the hydrocarbon group as R ¹³ may have include a halogen atom such as a fluorine atom, a sulfonic acid group, a carboxyl group, a hydroxyl group, an amino group, and a cyano group.

  As the organic sulfonic acid represented by the general formula (V), nonafluorobutanesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, dodecylbenzenesulfonic acid, or a mixture thereof is preferable.

  The acid catalyst acts as a catalyst when hydrolyzing the silane compound in the presence of water. The amount of the acid catalyst used is preferably such that the concentration of the acid catalyst in the reaction system of the hydrolysis reaction is 1 to 1000 ppm, more preferably 5 to 800 ppm. The amount of water used is determined according to the hydrolysis rate of the siloxane polymer to be obtained. In this specification, the hydrolysis rate of the siloxane polymer refers to the number of water molecules relative to the number of alkoxy groups (in moles) in the silane compound present in the reaction system of the hydrolysis reaction for synthesizing the siloxane polymer ( The number of moles) (unit:%). In the present invention, the hydrolysis rate of the siloxane polymer is preferably 50 to 200%, and more preferably 75 to 180%.

  Examples of the organic solvent that may be included in the reaction system of the hydrolysis reaction include monohydric alcohols such as methanol, ethanol, propanol, isopropanol (IPA), and n-butanol; methyl acetate, ethyl acetate, butyl acetate, methyl- Carboxylic acid esters such as 3-methoxypropionate and ethyl-3-ethoxypropionate; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, glycerin, trimethylolpropane, and hexanetriol; ethylene glycol monomethyl Ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoether Monoethers of polyhydric alcohols such as ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether; Monoacets of ethers; ketones such as acetone, methyl ethyl ketone, and methyl isoamyl ketone; ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, ethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether , Diethylene glycol Lumpur dimethyl ether, diethylene glycol diethyl ether, and diethylene polyhydric alcohol ethers were all alkyl-etherified hydroxyl of polyhydric alcohols such as methyl ethyl ether, and the like. The said organic solvent may be used independently and may be used in combination of 2 or more type.

  For example, the substrate 10 having the recesses 17 formed from a solution for forming the release film 19 containing a silane compound that is a precursor of the spion glass (SOG) material described above, an acid catalyst, water, and an organic solvent. After a coating film is formed by coating on the surface of the film, a release film 19 made of a spion glass (SOG) material is formed by causing a hydrolysis reaction and a condensation reaction to proceed in the coating film. Although the method to advance a hydrolysis reaction and a condensation reaction is not specifically limited, The method of heating the board | substrate with which the coating film was formed to 300-500 degreeC, Preferably it is 350-450 degreeC is mentioned. When the organic solvent remains in the release film 19, it is preferable to heat the substrate until the organic solvent is substantially removed from the release film 19.

  According to the manufacturing method of the mold 1 for manufacturing solder balls according to the first aspect described above, the mold 1 having a concave portion having a fine and uniform shape can be easily formed in a short time.

[Second embodiment]
The second aspect of the present invention is:
A solder filling step of filling the recesses on the mold for producing solder balls produced by the method according to the first aspect with solder,
A solder spheronization process in which the solder filled in the recesses is placed under a temperature equal to or higher than the melting point of the solder to spheroidize the solder;
A method for producing solder balls including:
Hereinafter, the solder filling process and the solder spheronization process will be described in order.

[Solder filling process]
As shown in FIGS. 2A to 2D, in the solder filling process, the solder is filled into the recesses 17 on the solder ball manufacturing mold 1 manufactured by the method according to the first aspect. . The solder that fills the recess 17 is not particularly limited, but a solder paste is usually used.

  Hereinafter, the solder paste 22 used in the solder filling process will be described. The solder paste 22 used in the second aspect of the present invention is used by appropriately selecting from the solder paste 22 conventionally used for producing solder balls. Typical components contained in the solder paste 22 include solder, which is a low melting point alloy, and flux. Solder and flux will be described in order.

(Solder)
The solder which is a low melting point alloy blended in the solder paste 22 is not particularly limited as long as the object of the present invention is not impaired. As a suitable example of the solder mix | blended with the solder paste 22, Sn-Ag-Cu series solder, Sn-Ag series solder, Sn-Cu series solder, Sn-Ag-Cu-Bi series solder, Sn-Ag-Bi -Lead solder containing no lead such as In solder, Sn-Cu-Ni solder, Sn-Bi solder, and Sn-Zn solder, and lead-containing solder such as Sn-Pb eutectic solder. . The solder paste 22 may contain a combination of a plurality of these solders.

  Among these solders, lead-free solders that do not contain lead are preferable in consideration of restrictions on the use of solder containing lead by the RoHS directive in Europe. Among lead-free solders, Sn-Ag-Cu solder is more preferable because of its excellent heat fatigue resistance.

(flux)
As a component of the flux blended in the solder paste 22, for example, based on a resin component, an activator, an organic halogen compound, a thixotropic agent, an organic solvent, and the like are used. In addition to the above components, an antioxidant, a rust inhibitor, a chelating agent, a leveling agent, an antifoaming agent, a dispersant, a matting agent, a colorant, and the like may be blended in the flux as desired.

  Specific examples of resin components used in the flux include natural resins such as natural rosin, disproportionated rosin, polymerized rosin, and hydrogenated rosin, polyester resin, polyurethane resin, silicone resin, epoxy resin, oxetane resin, and Examples include synthetic resins such as acrylic resins. These resins may be used in combination of two or more.

  Specific examples of the activator used in the flux include methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine. Hydrohalides, such as hydrochlorides, hydrobromides, etc., of amines such as trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, monoethanolamine, diethanolamine, and triethanolamine; Malonic acid, succinic acid, adipic acid, glutaric acid, diethyl glutaric acid, pimelic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, diglycolic acid, capric acid, lauric acid, myristic acid, palmitic acid, linoleic acid, oleic acid Stearic acid, arachidic acid, threonine acid behenyl, linolenic acid, benzoic acid, hydroxypivalic acid, dimethylolpropionic acid, citric acid, malic acid, glyceric acid, and salts of carboxylic acids such as lactic acid. These active agents may be used in combination of two or more.

  When these activators are blended in the flux, it is usually desirable to blend at a ratio of 30% by mass or less in the flux.

  Examples of the halogen contained in the organic halogen compound used for the flux include chlorine, bromine and iodine. Specific examples of the organic halide used in the flux include halogenated alcohols such as 3-bromo-1-propanol and 1,4-dibromo-2-butanol; ethyl bromoacetate, ethyl α-bromocaprylate, Halogenated aliphatic carboxylic acid esters such as ethyl α-bromopropionate, ethyl β-bromopropionate, and 9,10,12,13,15,16-hexabromostearic acid methyl ester; 2,3-dibromosuccinic acid Acids and halogenated aliphatic carboxylic acids such as 9,10,12,13,15,16-hexabromostearic acid; halogenated benzyl compounds such as 4-stearoyloxybenzyl bromide and 4-stearoylaminobenzyl bromide; bis ( 2,3-dibromopropyl) o-phthalamide and N, N Halogenated alkylamides such as N ′, N′-tetra (2,3-dibromopropyl) succinamide; 1-bromo-3-methyl-1-butene, and 2,2-bis [4- (2,3- Halogenated hydrocarbons such as dibromopropyl) -3,5-dibromophenyl] propane; halogen-containing ether compounds such as bis (2,3-dibromopropyl) glycerol and trimethylolpropane bis (2,3-dibromopropyl) ether Halogenated ketones such as 2,4-dibromoacetophenone; halogenated ureas such as N, N′-bis (2,3-dibromopropyl) urea; halogenation such as α, α, α-tribromomethylsulfone; Sulphones; succinate compounds such as bis (2,3-dibromopropyl) succinate; tris (2,3-dibromopropyl) Pills) isocyanurate compounds such as isocyanurate. These organic halides may be used in combination of two or more.

  When these organic halogen compounds are blended in the flux, it is usually desirable to blend in a proportion of 20% by mass or less in the flux.

  Specific examples of the thixotropic agent used in the flux include polyolefin waxes such as castor wax (cured castor oil); fatty acid amides such as m-xylylene bis stearamide; N-butyl-N′-stearyl urea, etc. Substituted urea wax; polymer compounds such as polyethylene glycol, polyethylene oxide, methyl cellulose, ethyl cellulose, and hydroxyethyl cellulose; inorganic particles such as silica particles and kaolin particles. These thixotropic agents may be used in combination of two or more.

  When these thixotropy imparting agents are blended in the flux, it is usually desirable to blend in the flux at a ratio of 30% by mass or less.

  Specific examples of organic solvents used in the flux include triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, ethylene glycol monophenyl ether, diethylene glycol. Monophenyl ether, diethylene glycol monobutyl acetate, dipropylene glycol, diethylene glycol-2-ethylhexyl ether, α-terpineol, benzyl alcohol, 2-hexyldecanol, butyl benzoate, diethyl maleate, diethyl adipate, sebacic acid Diethyl, dibutyl sebacate, diethyl phthalate , Dodecane, tetradecene, dodecylbenzene, ethylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, hexylene glycol, 1,5-pentanediol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether acetate, propylene glycol monoethyl Examples include ether acetate, butyl carbitol acetate, 3-methoxybutyl acetate, triethylene glycol butyl methyl ether, and triacetin. These organic solvents may be used in combination of two or more.

  When these organic solvents are blended in the flux, it is usually desirable to blend in the flux at a ratio of 50% by mass or less.

  The content of the flux in the solder paste 22 is not particularly limited as long as a solder ball having a desired shape can be produced, but is preferably 20% by mass or less, and more preferably 15% by mass or less with respect to the mass of the solder paste 22.

  In the solder filling step, as shown in FIG. 2 (b), after supplying the solder paste 22 to the end of the mold 1, the squeegee 21 is slid on the surface of the mold 1, and FIG. As shown in FIG. 2, the recess 17 on the mold 1 is filled with a solder paste. The shape and material of the squeegee 21 are not particularly limited as long as the concave portion 17 can be filled with solder well. Since the filling of the solder paste 22 into the recess 17 is easy, the material of the squeegee 21 is preferably a hard elastic material such as hard polyurethane.

  After the solder paste 22 is filled in the concave portion 17 on the mold 1 with the squeegee 21, the solder paste adhering to the surface of the mold 1 is scraped as necessary with a hard plate-like member such as a knife edge (not shown). It is preferable to drop.

[Solder spheroidization process]
As shown in FIGS. 2D and 2E, in the solder spheronization process, the solder (solder paste 22) filled in the recess 17 on the mold 1 is placed at a temperature equal to or higher than the melting point of the solder. The solder ball 23 is manufactured by making the solder spherical.

  Solder (solder paste 22) filled in the concave portion 17 on the mold 1 is melted by being placed at a temperature equal to or higher than the melting point of the solder, and is made spherical by the action of surface tension. The temperature at which the solder is spheroidized is not particularly limited as long as the temperature is not lower than the melting point of the solder and does not impair the object of the present invention. The temperature at which the solder is spheroidized is preferably 100 to 300 ° C., more preferably 130 to 160 ° C. when a low melting point solder is used, and more preferably 230 to 280 ° C. when a high melting point solder is used.

  The method for collecting the solder balls 23 formed in this way from the mold 1 is not particularly limited. As an example of a suitable method for collecting the solder balls 23, a solder ball collecting board (not shown) is brought close to the mold 1 from above the mold 1, so that the solder ball collecting board is brought into contact with the solder balls 23. There is a method in which the solder balls 23 are transferred to the substrate for collecting the solder balls in contact therewith.

  Further, the solder ball 23 is formed by using the mold 1 in which the concave portion 17 is formed in accordance with the position of the terminal of the element such as a semiconductor element, and the tip of the terminal of the element is brought into contact with the solder ball on the mold 1. The solder ball can be directly transferred to the terminal of the element.

  Since the solder ball manufacturing method according to the second aspect described above uses the mold for manufacturing solder balls manufactured by the method according to the first aspect, the particle diameter is uniform and the particle diameter is 70 μm or less. Such a fine solder ball can be manufactured, and the manufactured solder ball can be easily released from the mold.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

[Example 1]
A resin that is a sandblasting mask having an opening with a diameter of 50 μm, after a dry film of 50 μm thickness is attached to a predetermined position on a rectangular glass substrate of 335 mm × 354 mm, and then the dry film is exposed and developed. A pattern was formed. Next, the glass substrate provided with the resin pattern is subjected to sand blasting treatment using a green carborundum GC # 600 (particle diameter 20 μm ± 1.5 μm) as a blasting material at an injection pressure of 0.5 kg, and an opening diameter is formed on the glass substrate surface. A recess having a depth of 60 μm and 25 μm was formed. After immersing the substrate in a stripping solution (BF Hakukuri B, manufactured by Tokyo Ohka Kogyo Co., Ltd.) for 30 minutes, the substrate was washed with water and dried to peel the resin pattern from the substrate. Next, the inner surface of the recess was wet etched with hydrofluoric acid.

  After dividing the glass substrate provided with the wet-etched concave portion into a total of 36 pieces of 6 × 6 in width, one of the divided pieces was attached to a silicon substrate having a diameter of 200 mm. Next, using a spray coater, a release film forming material (LML-102, manufactured by Tokyo Ohka Kogyo Co., Ltd.) made of a spion glass material under the conditions of a discharge amount of 6.0 g / min, a pitch of 10 mm, and a scan stage temperature of 100 ° C. It apply | coated to the surface of the divided | segmented piece on a silicon substrate. The coating film applied to the surface of the divided pieces on the silicon substrate was heated at 100 ° C. for 1 minute to form a release film made of a spin-on-glass material having a thickness of 1 μm. Thereafter, the release coating was baked at 400 ° C. for 30 minutes in a baking furnace. The film thickness of the spion glass material was measured with a stylus type surface shape measuring instrument (DEKTAK, manufactured by ULVAC). The size of the recess on the mold formed by the above steps was an opening diameter of 65 to 70 μm and an opening depth of 23 μm.

After filling the concave part on the obtained mold with the solder paste, the mold filled with the solder paste was heated to melt the solder paste filled in the mold, thereby making the solder paste spherical. When a sphere-shaped soft solder paste on the mold is brought into contact with the solder ball recovery board from above the mold, all the solder balls are peeled off the mold and become a solder ball recovery board. Collected and collected. By the above method, a fine solder ball having a particle diameter of 43 to 44 μm and a uniform particle diameter could be produced.
[Example 2]

  A dry film having a thickness of 30 μm is attached to a predetermined position on a glass substrate on a rectangular glass substrate of 335 mm × 354 mm, and then the dry film is exposed and developed to have a 30 μm diameter opening for sandblasting. A resin pattern as a mask was formed. Next, the glass substrate provided with the resin pattern is subjected to sand blasting treatment using a green carborundum GC # 600 (particle diameter 20 μm ± 1.5 μm) as a blasting material at an injection pressure of 0.5 kg, and an opening diameter is formed on the glass substrate surface. A recess having a depth of 40 μm and a depth of 9 μm was formed. After immersing the substrate in a stripping solution (BF Hakukuri B, manufactured by Tokyo Ohka Kogyo Co., Ltd.) for 30 minutes, the substrate was washed with water and dried to peel the resin pattern from the substrate.

  After dividing the glass substrate provided with the concave portion into a total of 36 pieces of 6 × 6 in width, one of the divided pieces was attached to a silicon substrate having a diameter of 200 mm. Next, a spray coater is used to form a release film forming material (LML-102, manufactured by Tokyo Ohka Kogyo Co., Ltd.) made of spion glass under the conditions of a discharge rate of 6.0 g / min and a pitch of 10 mm and a scan stage temperature of 100 ° C. It apply | coated to the surface of the divided | segmented piece on a board | substrate. The coating film applied to the surface of the divided pieces on the silicon substrate was heated at 100 ° C. for 1 minute to form a release film made of a spin-on-glass material having a thickness of 1 μm. Thereafter, the release coating was baked at 400 ° C. for 30 minutes in a baking furnace. The film thickness of the spion glass material was measured with a stylus type surface shape measuring instrument (DEKTAK, manufactured by ULVAC). The size of the recess on the mold formed by the above steps was an opening diameter of 40 μm and an opening depth of 7 μm.

  After filling the concave part on the obtained mold with the solder paste, the mold filled with the solder paste was heated to melt the solder paste filled in the mold, thereby making the solder paste spherical. When a sphere-shaped soft solder paste on the mold is brought into contact with the solder ball recovery board from above the mold, all the solder balls are peeled off the mold and become a solder ball recovery board. Collected and collected. By the above method, a fine solder ball having a particle diameter of 18 μm and a uniform particle diameter could be manufactured.

[Comparative Example 1]
A mold for producing solder balls was produced in the same manner as in Example 1 except that the release film made of the SOG material was not formed on the substrate surface. Next, using the obtained mold, solder balls were produced in the same manner as in the examples. As a result, when solder balls were manufactured using the mold manufactured in the comparative example, some solder balls were not peeled off from the mold surface when the solder balls were collected.

[Comparative Example 2]
A mold for producing solder balls was produced in the same manner as in Example 1 except that a polyimide resin film having a film thickness of 4.5 μm was formed instead of the release film made of the SOG material. The polyimide resin film is made of a polyamic acid solution (diluting solvent: 3-methoxyblulacetate, solid content concentration 5%) on a glass substrate using a spray coater, a discharge amount of 5.0 g / min, a pitch of 5 mm, and a stage. After coating at a temperature of 90 ° C., the coating film was formed by heating at 260 ° C. for 10 minutes. Next, using the obtained mold, solder balls were produced in the same manner as in the examples. As a result, when solder balls were manufactured using the mold manufactured in the comparative example, some solder balls were not peeled off from the mold surface when the solder balls were collected.

DESCRIPTION OF SYMBOLS 1 Mold 10 Board | substrate 11 Photosensitive resin layer 12 Mask 13 Light 14 Developer 15 Resin pattern 16 Opening part 17 Recessed part 18 Stripping liquid 19 Release film 21 Squeegee 22 Solder paste 23 Solder ball

Claims (7)

Forming a photosensitive resin layer on the substrate surface, a photosensitive resin layer forming step;
A resin pattern forming step of exposing and developing the photosensitive resin layer to form a resin pattern having a circular opening of one or more predetermined diameters on the substrate;
Forming a substantially hemispherical recess on the surface of the substrate exposed from the circular opening on the resin pattern; and
A resin pattern peeling step for peeling the resin pattern;
A release film forming step of covering the inner surface of the recess and another substrate surface of the inner surface of the recess, and forming a release film having lower wettability with respect to the solder than the substrate surface;
The manufacturing method of the mold for solder ball manufacture containing this.   The method for manufacturing a mold for producing solder balls according to claim 1, wherein the recess is formed by sandblasting in the recess forming step.   The method for manufacturing a mold for producing solder balls according to claim 2, wherein the surface of the recess is subjected to a wet etching process after the recess forming step.   The release coating is selected from the group consisting of cobalt, nickel, tungsten, molybdenum, aluminum, chromium, titanium, iron, zinc, and alloys of these metals, chromates, phosphates, and spin-on-glass (SOG) materials. The manufacturing method of the mold for solder ball manufacture of any one of Claims 1-3 which consists of 1 or more types of materials which become.   The method for producing a mold for producing solder balls according to claim 4, wherein the release film is made of a spin-on-glass (SOG) material.   The method for producing a mold for producing solder balls according to claim 5, wherein the release film is formed by applying a solution containing a precursor of the spin-on-glass (SOG) material to the surface of the substrate. A solder filling step of filling the recesses on the mold for producing solder balls produced by the method according to any one of claims 1 to 6 with solder;
Placing the solder filled in the recesses at a temperature equal to or higher than the melting point of the solder to spheroidize the solder;
A method for producing a solder ball including:

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