JP2020099916A - Method for manufacturing molding solder - Google Patents

Abstract

To provide a method for manufacturing a molding solder by which a molding solder with a complex shape or thin thickness can be easily manufactured.SOLUTION: A method for manufacturing a molding solder, which uses a molding device which can perform compression molding of powders between a first pressure plate and a second pressure plate, comprises: a process in which a powder filling part is formed on the first pressure plate; a process in which conductive powders containing solder powders are filled in the powder filling part; and a process in which the conductive powders are compressed by the second pressure plate, thereby forming a molding solder.SELECTED DRAWING: Figure 2

Description

The present invention relates to a method for manufacturing molded solder.

The forming solder is formed into various shapes such as a circular shape, a rectangular shape or a washer shape according to the shape of the soldered portion. The manufacturing of this forming solder is usually performed by punching a band-shaped solder with a press (see Patent Document 1).

JP-A-9-29478

However, as described in Patent Document 1, when the molded solder is manufactured by punching the band-shaped solder with a press, a punching die for pressing is required for each type of the molded solder. Further, in such a case, it is difficult to manufacture a molding solder having a complicated shape or a molding solder having a small thickness.

It is an object of the present invention to provide a method of manufacturing a molding solder, which can manufacture a molding solder having a complicated shape and a small thickness by a simple method.

The method for producing a molded solder according to the present invention is a method for producing a molded solder using a molding device capable of compression-molding powder between a first pressure plate and a second pressure plate. A step of forming a powder filling portion, a step of filling the powder filling portion with a conductive powder containing a solder powder, and a step of compressing the conductive powder with the second pressure plate to form a molding solder. And a molding step.

In the method for producing a molded solder of the present invention, in the step of forming the powder-filled portion, a dry coating film of a photosensitive resin composition is formed on the first pressure plate, and then on the dry coating film. A photomask is placed on the substrate, and an exposure treatment of selectively irradiating ultraviolet light to a portion corresponding to the powder-filled portion is performed so that the portion is not irradiated with ultraviolet light, and then the coating film after the exposure treatment is subjected to a development treatment. It is preferable to form the powder filling part.
In the method of manufacturing the molded solder of the present invention, it is preferable that in the step of forming the powder filling portion, the powder filling portion is formed by disposing a tubular member on the first pressure plate.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the shaping|molding solder which can manufacture a complicated shape and thin shaping|molding solder by a simple method can be provided.

It is a schematic diagram showing the 1st press plate and the 2nd press plate in a forming device. It is a figure for demonstrating the manufacturing method of the forming solder of 1st embodiment of this invention. It is a figure for demonstrating the manufacturing method of the shaping|molding solder of 2nd embodiment of this invention.

[First embodiment]
Hereinafter, the present invention will be described with reference to the drawings by taking an embodiment as an example. The present invention is not limited to the content of the embodiment. In the drawings, there are some portions that are enlarged or reduced for ease of explanation.

As shown in FIG. 1, the method of manufacturing the molded solder of the present embodiment is a method of manufacturing the molded solder using a molding device capable of compression molding powder between the first pressure plate 11 and the second pressure plate 12. Is. As this forming apparatus, a known forming apparatus can be adopted as appropriate, and for example, a briquette machine or the like can be adopted.

As shown in FIGS. 2(A) to 2(H), the method of manufacturing the molded solder of the present embodiment includes a step of forming the powder filling portion 13 on the first pressure plate 11 (filling portion forming step), and a powder. A step of filling the filling portion 13 with the conductive powder 3 containing the solder powder (solder powder filling step), and a step of compressing the conductive powder 3 with the second pressure plate 12 to form the shaped solder 3a ( Molding step).

(Filling part forming process)
In the filling portion forming step, the powder filling portion 13 is formed on the first pressure plate 11.
In this filling portion forming step, first, the dry coating film 2 of the photosensitive resin composition shown in FIG. 2(B) is formed on the first pressure plate 11 shown in FIG. 2(A).
The photosensitive resin composition used in this embodiment preferably contains (A) a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, and (C) a diluent. Further, the photosensitive resin composition used in the present embodiment preferably further contains (D) an epoxy compound and (E) a filler, if necessary.

The component (A) is, for example, a photosensitive carboxyl group-containing resin having one or more photosensitive unsaturated double bonds or a carboxyl group-containing resin having no photosensitive unsaturated double bond. As the component (A), for example, at least a part of the epoxy groups of the alicyclic epoxy resin having two or more epoxy groups in the molecule is reacted with a radically polymerizable unsaturated monocarboxylic acid such as acrylic acid or methacrylic acid. Then, a product obtained by reacting the generated hydroxyl group with a polybasic acid anhydride can be used.

The component (B) is not particularly limited as long as it is a known photopolymerization initiator. Examples of the component (B) include oxime-based initiators, benzoin, acetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenylketone, and benzophenone.
The blending amount of the component (B) is, for example, 5 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the component (A).

The component (C) is not particularly limited as long as it is a known photopolymerizable monomer. The component (C) is used for sufficiently curing the light of the component (A) to obtain a coating film having acid resistance, heat resistance, alkali resistance and the like. Examples of the component (C) include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and polyethylene glycol di(meth)acrylate. Are listed.
The blending amount of the component (C) is, for example, 2 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the component (A).

The component (D) is for increasing the crosslink density of the cured coating film in the photosensitive resin composition. Examples of the component (D) include epoxy resin.
Examples of the epoxy resin include bisphenol A type epoxy resin, novolac type epoxy resin (phenol novolac type epoxy resin, o-cresol novolac type epoxy resin, p-tert-butylphenol novolac type epoxy resin), bisphenol F type or bisphenol S type epoxy resin. (Epoxy resin obtained by reacting bisphenol F or bisphenol S with epichlorohydrin), alicyclic epoxy resin (epoxy resin having cyclohexene oxide group, tricyclodecane oxide group, cyclopentene oxide group), triglycidyl isocyanurate ( Examples thereof include tris(2,3-epoxypropyl)isocyanurate, triglycidyl tris(2-hydroxyethyl)isocyanurate, etc., dicyclopentadiene type epoxy resin, and adamantane type epoxy resin.
The blending amount of the component (D) is, for example, 10 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the component (A).

The component (E) is inorganic fine particles, and is used for suppressing the deformation of the cured coating film of the photosensitive resin composition due to heat or the like. Examples of the component (E) include barium sulfate, talc, and silica. Among these, silica is particularly preferable from the viewpoint of reducing deformation due to pressure and obtaining a molded solder having a desired thickness.
The blending amount of the component (E) is preferably 10 parts by mass or more and 120 parts by mass or less, and more preferably 30 parts by mass or more and 70 parts by mass with respect to 100 parts by mass of the component (A). When the blending amount of the component (E) is at least the above lower limit, the deformation of the cured coating film of the photosensitive resin composition can be further suppressed. On the other hand, when the blending amount of the component (E) is at most the above upper limit, the accuracy of pattern formation of the photosensitive resin composition can be improved.

In addition to the components (A) to (E) described above, the photosensitive resin composition used in the present embodiment may optionally contain various additive components, if necessary. Examples of the additive component include a defoaming agent, a coloring agent, an antioxidant, and a coupling agent.

The method for forming the dry coating film 2 of the photosensitive resin composition is not particularly limited, but (i) a dry film is prepared in advance from the photosensitive resin composition, and this dry film is applied to the first pressure plate 11. A method of laminating, or (ii) a method of applying the photosensitive resin composition to the first pressure plate 11 using a coating device and drying it if necessary can be adopted.
Examples of the coating device used in such a case include a roll coater, a curtain coater, a spray coater, a dip coater, a bar coater, an applicator, a screen printer, a die coater, a lip coater, a comma coater, and a gravure coater. Among these, a screen printer is preferable from the viewpoint of workability.
The drying condition is, for example, at a temperature of 70° C. or higher and 85° C. or lower for 10 minutes or more and 30 minutes or less.

In this filling portion forming step, next, as shown in FIG. 2(C), a photomask 9 is arranged on the dry coating film 2, and a portion corresponding to the powder filling portion 13 is selected so as not to be irradiated with ultraviolet light. Then, an exposure process for irradiating ultraviolet light is performed.
The exposure amount and the like in the exposure processing may be appropriately set according to the photosensitive resin composition used and the exposure apparatus.

In this filling portion forming step, next, the coating film after the exposure processing is subjected to a developing treatment to form the powder filling portion 13 as shown in FIG. 2(D).
The powder filling portion 13 may be formed at two or more places. Thereby, two or more forming solders 3a can be simultaneously produced.
The developing temperature and the developing time in the developing treatment may be appropriately set according to the photosensitive resin composition used and the developing device.

Further, the coating film after the exposure treatment may be further subjected to a heat curing treatment. By such heat curing treatment, the deformation of the cured coating film 2a of the photosensitive resin composition can be further suppressed.
The heating temperature and heating time in the heat curing treatment may be appropriately set according to the photosensitive resin composition used and the heating device.

The thickness of the cured coating film 2a is not particularly limited, but is usually 10 μm or more and 500 μm or less. A thickness of about 90% or more and 100% or less of the thickness of the cured coating film 2a is the thickness of the obtained forming solder 3a. That is, by adjusting the thickness of the cured coating film 2a, the thickness of the obtained forming solder 3a can be adjusted. Further, the thickness of the cured coating film 2a is more preferably 20 μm or more, further preferably 30 μm or more, and particularly preferably 40 μm or more from the viewpoint of increasing the thickness of the molding solder 3a. On the other hand, the thickness of the cured coating film 2a is more preferably 300 μm or less, further preferably 200 μm or less, and 100 μm, from the viewpoint of workability and the viewpoint of making the thickness of the forming solder 3a thinner. The following is particularly preferable.

(Solder powder filling process)
In the solder powder filling step, as shown in FIG. 2(E), the powder filling portion 13 is filled with the conductive powder 3 containing the solder powder.
Here, it is preferable that the conductive powder 3 be filled in a larger amount than the volume of the powder filling portion 13. By doing so, the conductive powder 3 can be compression-molded more reliably.
The solder powder used in this embodiment is preferably made of only lead-free solder powder, but may be leaded solder powder. As a solder alloy in this solder powder, an alloy containing tin as a main component is preferable. The second element of this alloy includes silver, copper, zinc, bismuth, antimony and the like. Further, other elements (third element and later) may be added to this alloy as needed. Other elements include copper, silver, bismuth, antimony, aluminum, indium and the like.
Specific examples of the alloy composition of the lead-free solder powder include Sn/Ag, Sn/Ag/Cu, Sn/Cu, Sn/Ag/Bi, Sn/Bi, Sn/Ag/Cu/Bi, Sn/Sb. And Sn/Zn/Bi, Sn/Zn, Sn/Zn/Al, Sn/Ag/Bi/In, Sn/Ag/Cu/Bi/In/Sb, and In/Ag.
These solder powders may be used alone or in combination of two or more.

The average particle diameter of the solder powder is preferably 1 μm or more and 40 μm or less, more preferably 2 μm or more and 35 μm or less, and particularly preferably 3 μm or more and 25 μm or less. The average particle size can be measured by a dynamic light scattering particle size measuring device.

The conductive powder 3 may be a powder composed only of solder powder, or may be a mixed powder of solder powder and conductive powder other than solder powder. Examples of the conductive powder other than the solder powder include inorganic particles (nickel, copper, silver, carbon, etc.), particles in which a highly conductive metal (silver, gold, etc.) is coated on the surface of the inorganic particles, and organic particles. Examples thereof include particles whose surface is coated with a metal having high conductivity (silver, gold, etc.). These may be used alone or in combination of two or more.

(Molding process)
In the molding step, the conductive powder 3 is compressed by the second pressure plate 12 as shown in FIG. 2(F), and the molded solder 3a is molded as shown in FIG. 2(G).
The load during molding is preferably 100 kN or more and 1000 kN or less, more preferably 150 kN or more and 500 kN or less, and particularly preferably 200 kN or more and 400 kN or less, from the viewpoint of obtaining an appropriate molding solder.
The molding time is not particularly limited, but is usually 10 seconds or more and 120 seconds or less.
The temperature during molding is not particularly limited, but is usually 15° C. or higher and 40° C. or lower.

The molded solder 3a thus obtained can be taken out and used as shown in FIG. From the viewpoint of making it easier to take out the molded solder 3a, a release agent treatment may be performed before the solder powder filling step. Examples of the release agent include a fluorine-based release agent and a silicone-based release agent.
Further, the cured coating film 2a may be peeled off from the first pressure plate 11 after the forming solder 3a is produced. Thereby, the cured coating film 2a having a different pattern can be formed on the first pressure plate 11, and the molding solder 3a having a different shape can be separately prepared.
As a method of peeling the cured coating film 2a, a method of dissolving the dried coating film 2 with an alkaline aqueous solution and peeling it can be adopted.
The alkaline aqueous solution may be appropriately selected according to the photosensitive resin composition used. Examples of such alkaline aqueous solution include potassium hydroxide aqueous solution and sodium hydroxide aqueous solution. The concentration of such an alkaline aqueous solution is preferably, for example, 1% by mass or more and 5% by mass or less.

(Operation and effect of the first embodiment)
According to this embodiment, the following operational effects can be achieved.
(1) The powder filling part 13 is formed using a photosensitive resin composition. Therefore, the shape and thickness of the powder filling portion 13 can be freely changed. In this way, a molding solder having a complicated shape and a small thickness can be manufactured by a simple method.
(2) Since the cured coating film 2a can be peeled off, the cured coating film 2a can be peeled off to form a cured coating film 2a having another pattern. As a result, the shaped solder 3a having another shape can be manufactured.

[Second embodiment]
Next, a second embodiment of the present invention will be described based on the drawings.
As shown in FIGS. 3(A) to 3(F), the method for manufacturing the molded solder of the present embodiment includes a step of forming the powder filling portion 13 on the first pressure plate 11 (filling portion forming step), and a powder. A step of filling the filling portion 13 with the conductive powder 3 containing the solder powder (solder powder filling step), and a step of compressing the conductive powder 3 with the second pressure plate 12 to form the shaped solder 3a ( Molding step).
The present embodiment has the same configuration as that of the first embodiment except that the filling portion forming step is different. Therefore, the filling portion forming step will be described and the other description will be omitted.

In the filling portion forming step in the present embodiment, the powder filling portion 13 is formed by disposing the tubular member 8 shown in FIG. 3B on the first pressure plate 11 shown in FIG. 3A.
Two or more tubular members 8 may be used. Thereby, two or more forming solders 3a can be simultaneously produced.
The shape of the tubular member 8 is not particularly limited. The cylindrical member 8 and the first pressure plate 11 form a powder filling portion 13. That is, the inner shape of the tubular member 8 becomes the shape of the obtained molded solder 3a.
The material of the tubular member 8 is not particularly limited. The material of the tubular member 8 is, for example, aluminum, stainless steel, or the like.

The thickness of the tubular member 8 is not particularly limited, but is usually 100 μm or more and 5000 μm or less. A thickness of about 70% or more and 100% or less of the thickness of the tubular member 8 is the thickness of the obtained molding solder 3a. Further, when the material of the tubular member 8 is a soft material such as aluminum, the thickness of the obtained molding solder 3a becomes thin. That is, by adjusting the thickness and the material of the tubular member 8, the thickness of the obtained molded solder 3a can be adjusted. Further, the thickness of the tubular member 8 is more preferably 200 μm or more, further preferably 300 μm or more, and particularly preferably 400 μm or more, from the viewpoint of increasing the thickness of the molding solder 3a. On the other hand, the thickness of the tubular member 8 is more preferably 1000 μm or less, further preferably 500 μm or less, and more preferably 200 μm, from the viewpoint of workability and the viewpoint of making the thickness of the molding solder 3a thinner. The following is particularly preferable.

(Operation and effect of the second embodiment)
According to this embodiment, the following operational effects can be achieved.
(3) The powder filling portion 13 is formed using the tubular member 8. Therefore, the shape and thickness of the powder filling portion 13 can be freely changed. In this way, a molding solder having a complicated shape and a small thickness can be manufactured by a simple method.
(4) Since the tubular member 8 can be replaced, it can be replaced with another tubular member 8 having another shape as appropriate. As a result, the shaped solder 3a having another shape can be manufactured.

[Modification of Embodiment]
The present invention is not limited to the above-described embodiments, but includes modifications and improvements as long as the object of the present invention can be achieved.
For example, in the above-described first embodiment, the cured coating film 2a of the photosensitive resin composition is formed, but the present invention is not limited to this. For example, a thermosetting resin composition or an ultraviolet curable resin composition may be used instead of the photosensitive resin composition. In such a case, for example, a screen printing machine can be used to form the patterned cured coating film 2a.
In the above-described first embodiment, the cured coating film 2a is formed every time the molded solder 3a is manufactured, but the invention is not limited to this. The cured coating film 2a can be used more than once, and the formed cured coating film 2a may be repeatedly used to produce a plurality of forming solders 3a having the same shape and the same thickness.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
[Example 1]
First, the following components (A) to (E) and other components were blended and mixed and dispersed at room temperature using a three-roll to prepare a photosensitive resin composition.
(A) Carboxyl group-containing photosensitive resin (100 parts by mass): "ZFR-1124", manufactured by Nippon Kayaku Co., Ltd. (B) Photopolymerization initiator-1 (6 parts by mass): "Irgacure 369", manufactured by BASF ( B) Photopolymerization initiator-2 (1 part by mass): "NCI-831", manufactured by ADEKA (C) Diluent (20 parts by mass): "M-400", manufactured by Toagosei (D) Epoxy compound ( 20 parts by mass): "EPICLON 860", DIC (E) filler (80 parts by mass): Filler having crystalline silica as a main component, "Min-u-sil 5", Air Brown (others) Foaming agent (1 part by mass): "KS-66", manufactured by Shin-Etsu Silicone Co., Ltd. The photosensitive resin composition obtained was screen-printed on the first pressure plate 11 shown in FIG. 2(A). Was formed (printed twice) and pre-dried (at a temperature of 80° C. for 20 minutes) to form a dry coating film 2 on the first pressure plate 11 as shown in FIG. 2B (dry). Thickness 80 μm). Then, as shown in FIG. 2(C), a photomask 9 is arranged on the dry coating film 2 to selectively expose the portion corresponding to the powder filling portion 13 to ultraviolet light (exposure amount). Exposure treatment was performed by irradiating 300 mJ). Then, the dry coating film 2 after the exposure treatment is subjected to a development treatment (1% sodium carbonate), and then subjected to a heat curing treatment at 150° C. for 10 minutes, so that the first coating is performed as shown in FIG. A cured coating film 2a having a plurality of powder filling parts 13 was formed on the pressure plate 11.
Next, as shown in FIG. 2(E), conductive powder 3 (alloy composition: Sn-3.0Ag-0.5Cu, average particle diameter: 3 μm) was filled. Thereafter, as shown in FIG. 2(F), the conductive powder 3 is compressed by the second pressure plate 12 under the condition of a load of about 300 kN for 30 seconds, as shown in FIGS. 2(G) and (H). Thus, the molded solder 3a was formed and taken out.
The shape of the obtained molded solder 3a was the same as the shape of the powder filling portion 13, and the thickness was 80 μm.
The cured coating film 2a was dissolved in a 3% aqueous potassium hydroxide solution (temperature: 50° C.) and removed from the first pressure plate 11.

[Example 2]
Except that the conductive powder 3 (alloy composition: Sn-58Bi, particle size distribution: 15 to 25 μm) was used, the shape was the same as that of the powder filling portion 13 and the thickness was 80 μm in the same manner as in Example 1. Formed solder 3a was produced.

[Example 3]
Other than using the conductive powder 3 (mixed powder of 50 mass% of copper powder (average particle size: 3 μm) and solder powder (alloy composition: Sn-50In, particle size distribution: 15 to 25 μm)), In the same manner as in Example 1, a molded solder 3a having the same shape as the powder filling portion 13 and a thickness of 80 μm was produced.

[Example 4]
As shown in FIG. 3B, the cylindrical member 8 (washer, shape: circular, inner diameter: 15 mm, outer diameter: 23 mm, thickness: 130 μm) is arranged on the first pressure plate 11, and the powder filling portion 13 is provided. Formed.
Next, as shown in FIG. 3C, conductive powder 3 (alloy composition: Sn-3.0Ag-0.5Cu, average particle diameter: 3 μm) was filled. After that, as shown in FIG. 3D, the conductive powder 3 is compressed by the second pressure plate 12 under the condition of a load of about 300 kN for 30 seconds, as shown in FIGS. As described above, the molded solder 3a was formed and taken out.
The shape of the obtained molded solder 3a was a circle having a diameter of 15 mm, and the thickness was 130 μm.

INDUSTRIAL APPLICABILITY The method for producing a molded solder according to the present invention is useful as a technique for producing a molded solder.

11... 1st pressurizing plate 12... 2nd pressurizing plate 13... Powder filling part 2... Dry coating film 2a... Cured coating film 3... Conductive powder 3a... Molding solder 8... Cylindrical member 9... Photomask

Claims (3)

A method for producing a molding solder using a molding apparatus capable of compression-molding powder between a first pressure plate and a second pressure plate,
Forming a powder filling portion on the first pressure plate;
In the powder filling portion, a step of filling a conductive powder containing a solder powder,
A step of compressing the conductive powder with the second pressure plate to form a molded solder. The method for manufacturing the molded solder according to claim 1,
In the step of forming the powder filling portion,
Forming a dry coating film of the photosensitive resin composition on the first pressure plate,
Next, a photomask is arranged on the dry coating film, and an exposure treatment for selectively irradiating ultraviolet light to a portion corresponding to the powder-filled portion so that the ultraviolet light is not irradiated is performed,
Then, the coating film after the exposure treatment is subjected to a development treatment to form the powder filling portion. The method for manufacturing the molded solder according to claim 1,
In the step of forming the powder filling portion,
The method for producing a molded solder, wherein the powder filling portion is formed by disposing a tubular member on the first pressure plate.

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