CN115362044A - Solder particle, method for producing solder particle, and substrate with solder particle - Google Patents
Solder particle, method for producing solder particle, and substrate with solder particle Download PDFInfo
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- CN115362044A CN115362044A CN202180026545.8A CN202180026545A CN115362044A CN 115362044 A CN115362044 A CN 115362044A CN 202180026545 A CN202180026545 A CN 202180026545A CN 115362044 A CN115362044 A CN 115362044A
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Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/24—Selection of soldering or welding materials proper
- B23K35/26—Selection of soldering or welding materials proper with the principal constituent melting at less than 400 degrees C
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/24—Selection of soldering or welding materials proper
- B23K35/30—Selection of soldering or welding materials proper with the principal constituent melting at less than 1550 degrees C
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/40—Making wire or rods for soldering or welding
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C12/00—Alloys based on antimony or bismuth
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C13/00—Alloys based on tin
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C28/00—Alloys based on a metal not provided for in groups C22C5/00 - C22C27/00
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C5/00—Alloys based on noble metals
- C22C5/02—Alloys based on gold
Abstract
The present invention provides a method for manufacturing solder particles, which includes: a preparation step of preparing a base having a plurality of projections; a solder layer forming step of forming a solder layer on the convex portion of at least a part of the base body; and a fusing step of fusing the solder layer formed on the convex portion to form solder particles on the convex portion.
Description
Technical Field
The present invention relates to solder particles, a method for producing solder particles, and a substrate with solder particles.
Background
Conventionally, the use of solder particles has been studied as conductive particles to be mixed with an anisotropic conductive material such as an anisotropic conductive film or an anisotropic conductive paste. For example, patent document 1 describes a conductive paste containing a thermosetting component and a plurality of solder particles subjected to a specific surface treatment.
Prior art documents
Patent document
Disclosure of Invention
Technical problem to be solved by the invention
In recent years, as circuit components have been made finer and connection portions have been made finer, the conduction reliability and insulation reliability required for anisotropic conductive materials have been improved. However, in the conventional method for producing solder particles, it is difficult to produce solder particles having both a small average particle diameter and a narrow particle size distribution.
The present invention has been made in view of the above problems, and an object thereof is to provide a method for producing solder particles capable of producing solder particles having a small average particle diameter and a narrow particle size distribution. It is another object of the present invention to provide solder particles having both a small average particle diameter and a narrow particle size distribution by the above-mentioned production method.
Means for solving the technical problem
One aspect of the present invention relates to a method of manufacturing solder particles, including: a preparation step of preparing a base having a plurality of projections; a solder layer forming step of forming a solder layer on the convex portion of at least a part of the base body; and a fusing step of fusing the solder layer formed on the convex portion to form solder particles on the convex portion.
According to the above-described manufacturing method, solder particles having a desired particle diameter can be obtained with a narrow particle size distribution by appropriately adjusting the shape of the convex portion and the thickness of the solder layer. That is, according to the above-mentioned production method, solder particles having a small average particle diameter and a narrow particle size distribution, which have been difficult to produce in the past, can be easily produced.
In one aspect, the convex portion may be columnar or truncated cone-shaped.
In one aspect, the substrate may have a first surface including a plurality of convex portions and bottom portions formed between the convex portions, and a ratio of a projected area of the bottom portions to a projected area of the first surface may be 8% or more.
In the manufacturing method of the aspect, in the solder layer forming step, the solder layer may be formed on the convex portion by at least one method selected from the group consisting of plating, vapor deposition, sputtering, and spraying.
The manufacturing method according to one aspect may further include, before the fusing step, a reducing step of exposing the solder layer formed on the projection to a reducing atmosphere.
In the manufacturing method according to one aspect, in the fusing step, the solder layer formed on the projection may be fused in a reducing atmosphere.
In one aspect, the solder layer may include at least one selected from the group consisting of tin, a tin alloy, indium, and an indium alloy.
In one aspect, the solder layer may include at least one selected from the group consisting of an In-Bi alloy, an In-Sn-Ag alloy, an Sn-Au alloy, an Sn-Bi-Ag alloy, an Sn-Ag-Cu alloy, and an Sn-Cu alloy.
Another aspect of the present invention relates to solder particles having an average particle diameter of 100nm or more and less than 1 μm and a c.v. value of 20% or less.
In the solder particle according to the first aspect, when a quadrangle circumscribing a projection image of the solder particle is formed by two pairs of parallel lines, X and Y satisfy the following expression when the distance between the opposing sides is X and Y < X,
0.8＜Y/X＜1.0。
the solder particles of one embodiment may include at least one selected from the group consisting of tin, a tin alloy, indium, and an indium alloy.
The solder particles of one embodiment may contain at least one selected from the group consisting of an In-Bi alloy, an In-Sn-Ag alloy, an Sn-Au alloy, an Sn-Bi-Ag alloy, an Sn-Ag-Cu alloy, and an Sn-Cu alloy.
Another aspect of the present invention relates to a substrate with solder particles, including: a base having a plurality of projections; and a plurality of solder particles disposed on the convex portion of the base. Such a substrate with solder particles can be easily manufactured by the fusion step in the above-described manufacturing method. The substrate with solder particles can easily transport, store and manage the solder particles.
In one embodiment, the solder particles may have an average particle diameter of 100nm or more and less than 1 μm, and the solder particles may have a c.v. value of 20% or less.
Effects of the invention
According to the present invention, there is provided a method for producing solder particles capable of producing solder particles having both a small average particle diameter and a narrow particle size distribution. Further, according to the present invention, there is provided solder particles having both a small average particle diameter and a narrow particle size distribution.
Drawings
Fig. 1 (a) is a plan view schematically showing an example of the substrate, and fig. 1 (b) is a cross-sectional view taken along line Ib-Ib shown in fig. 1 (a).
Fig. 2 (a) is a cross-sectional view schematically showing an example of the convex portion, and fig. 2 (b) is a cross-sectional view schematically showing another example of the convex portion.
Fig. 3 (a) to (e) are schematic diagrams showing examples of the shapes of cross sections perpendicular to the height direction of the convex portions.
Fig. 4 is a cross-sectional view schematically showing an example of a state in which a solder layer is formed on the convex portion of the base.
Fig. 5 is a cross-sectional view schematically showing an example of a state in which solder particles are formed on the convex portions of the base.
Fig. 6 is a cross-sectional view schematically showing another example of a state in which a solder layer is formed on the convex portion of the base.
Fig. 7 is a cross-sectional view schematically showing another example of a state where solder particles are formed on the convex portions of the base.
Fig. 8 is a diagram showing distances X and Y between opposing sides (where Y < X) when a square circumscribing a projection image of solder particles is made of two pairs of parallel lines.
Fig. 9 is an SEM image of the substrate prepared in example 13.
Fig. 10 is an SEM image of a state in which a solder layer was formed on the convex portion of the base in example 13.
Fig. 11 is an SEM image of a state in which solder particles were formed on the convex portions of the base in example 13.
Fig. 12 is an SEM image of the solder particles obtained in example 2.
Fig. 13 is an SEM image of the solder particles obtained in comparative example 2.
Detailed Description
Hereinafter, embodiments of the present invention will be described. The present invention is not limited to the following embodiments. In addition, unless otherwise specified, materials exemplified below may be used alone or in combination of two or more. In the case where a plurality of substances corresponding to the respective ingredients are present in the composition, the content of each ingredient in the composition means the total amount of the plurality of substances present in the composition unless otherwise specified. The numerical range shown by the term "to" indicates a range in which the numerical values before and after the term "to" are included as the minimum value and the maximum value, respectively. In the numerical ranges recited in the present specification, the upper limit or the lower limit of the numerical range in one stage may be replaced with the upper limit or the lower limit of the numerical range in another stage. In the numerical ranges described in the present specification, the upper limit or the lower limit of the numerical range may be replaced with the values shown in the examples.
< method for producing solder particles >
The method for manufacturing solder particles according to the present embodiment includes: a preparation step of preparing a base having a plurality of projections; a solder layer forming step of forming a solder layer on the convex portion of at least a part of the base; and a fusing step of fusing the solder layer formed on the convex portion to form solder particles on the convex portion.
According to the above-described manufacturing method, solder particles having a desired particle diameter can be obtained with a narrow particle size distribution by appropriately adjusting the shape of the convex portion and the thickness of the solder layer. That is, according to the above-mentioned production method, it is possible to easily produce solder particles (for example, solder particles having an average particle diameter of 100nm to 30 μm and a C.V. value of 20% or less) having a small average particle diameter and a narrow particle size distribution, which have been difficult to produce conventionally.
Further, according to the above-described manufacturing method, solder particles which are difficult to manufacture by a conventional method can be obtained. For example, according to the above production method, extremely small solder particles having an average particle diameter of 100nm or more and less than 1 μm can be obtained with a narrow particle size distribution (for example, a c.v. value of 20% or less).
Hereinafter, a method for producing solder particles will be described with reference to fig. 1 to 7.
First, a base body for forming a solder layer is prepared (preparation step). Fig. 1 (a) is a schematic view showing an example of the substrate, and fig. 1 (b) is a cross-sectional view taken along line Ib-Ib shown in fig. 1 (a). The base 10 shown in fig. 1 (a) has a plurality of projections 11. The plurality of projections 11 may be regularly arranged in a predetermined pattern. In this case, the solder particles formed on the convex portions 11 can be regularly arranged by transferring the solder particles to a resin material or the like.
The base 10 may have a first surface 10a, and the first surface 10a may include a plurality of projections 11 and a bottom portion 12 formed between the projections 11. The first surface 10a may be constituted by a top 11a of the convex portion 11 and a bottom surface 12a constituted by the bottom 12.
If the convex portions 11 are excessively close to each other, the solder particles on the convex portions 11 may come into contact with each other and fuse together in a fusing step described later, thereby generating solder particles having a large particle size. From the viewpoint of suppressing the formation of such large-particle-diameter particles, the ratio of the projected area of the bottom portion 12 to the projected area of the first surface 10a (i.e., the ratio of the area of the bottom portion 12a to the projected area of the first surface 10 a) is preferably 8% or more, more preferably 10% or more, and may be 15% or more. The upper limit of the ratio is not particularly limited. From the viewpoint of further improving the production efficiency of the solder particles, for example, it may be 95% or less, preferably 90% or less, and more preferably 80% or less.
In fig. 1 (a) and 1 (b), the projection 11 is formed in a cylindrical shape, but the shape of the projection 11 is not limited thereto. The convex portion 11 may have a cylindrical shape such as a cylindrical shape, an elliptic cylindrical shape, a triangular cylindrical shape, a quadrangular cylindrical shape, or a polygonal cylindrical shape, or may have a truncated cone shape such as a truncated cone shape, an elliptic cone shape, a triangular truncated cone shape, a quadrangular truncated cone shape, or a polygonal truncated cone shape.
In fig. 1 (a) and 1 (b), the top 11a of the projection 11 is described as a flat surface, but the top 11a does not necessarily have to be a flat surface. For example, the top 11a may have a recess or a protrusion. From the viewpoint of improving the holding property of the solder particles formed on the top portion 11a, the top portion 11a preferably has a depression in the center.
Fig. 2 (a) is a cross-sectional view schematically showing an example of the convex portion, and fig. 2 (b) is a cross-sectional view schematically showing an example of the convex portion. The convex portion 11 shown in fig. 2 (a) is a columnar convex portion, and the convex portion 21 shown in fig. 2 (b) is a truncated cone-shaped convex portion.
In the convex portion 11, the width D in the top portion 11a 11 And a width D in the contact surface with the bottom 12 12 May be substantially the same. Width D 11 And width D 12 The thickness is not particularly limited, and may be, for example, 200nm or more, preferably 400nm or more, and more preferably 1.0 μm or more, from the viewpoint of avoiding contact between solder particles on adjacent projections. And, a width D 11 And width D 12 For example, it may be 10 μm or less, and from the viewpoint of producing solder particles having an extremely small particle diameter of 800nm or less, it is preferably 4.0 μm or less, and more preferably 2.0 μm or less.
Height H of convex portion 11 1 The width D is not particularly limited, and may be, for example 11 The width D is preferably 10% or more, from the viewpoint of avoiding contact with the solder on the bottom portion 12 and easily obtaining solder particles with higher accuracy 11 Is 25% or more, more preferably the width D 11 More than 50%. And, the height H of the convex part 11 1 For example, it may be a width D 11 Is preferably 1000% or less, and the width D is preferably set to avoid damage to the projection 11 and to further improve the recovery rate of solder particles 11 Is 500% or less, more preferably the width D 11 Less than 300%.
The projection 11 can be disposed at any position on the base 10.
Distance L between adjacent projections 11 1 The width D is not particularly limited, but may be, for example, the width D from the viewpoint of suppressing the formation of large-diameter particles due to contact and fusion of solder particles on the projections 11 11 Is preferably not less than 3%, and the width D is preferably set 11 Is 8% or more, more preferably the width D 11 More than 15%. And, the distance L between the adjacent convex portions 11 1 For example, it may be a width D 11 Is preferably 1000% or less, and the width D is preferably set to further improve the production efficiency of the solder particles 11 Is 500% or less, more preferably the width D 11 Less than 200%。
Width D of the convex portion 21 at the top 21a 21 Less than the width D in the contact surface with the bottom 22 22 . Width D 21 The thickness is not particularly limited, and may be, for example, 200nm or more, preferably 400nm or more, and more preferably 1.0 μm or more, from the viewpoint of avoiding contact between solder particles on adjacent projections. And, width D 21 For example, it may be 10 μm or less, and from the viewpoint of producing solder particles having an extremely small particle diameter of 800nm or less, it is preferably 4.0 μm or less, and more preferably 2.0 μm or less. Width D 22 The thickness is not particularly limited, and may be, for example, 200nm or more, preferably 400nm or more, and more preferably 1.0 μm or more, from the viewpoint of avoiding contact between solder particles on adjacent projections. And, a width D 22 For example, the particle size may be 10 μm or less, and is preferably 4.0 μm or less, more preferably 2.0 μm or less, from the viewpoint of producing solder particles having an extremely small particle size of 800nm or less.
Width D 21 And width D 22 Ratio of (D) 22 /D 21 ) The number of the projections is not particularly limited, and may be, for example, 1.1 or more, but is preferably 1.3 or more, and more preferably 1.5 or more, from the viewpoint of avoiding contact between solder particles on adjacent projections. And, the above ratio (D) 22 /D 21 ) For example, it may be 3.0 or less, preferably 2.0 or less.
Width D 21 And width D 22 Difference of difference (D) 22 -D 21 ) The thickness is not particularly limited, and may be, for example, 2.0 μm or less, but is preferably 1.0 μm or less, and more preferably 500nm or less, from the viewpoint of reducing the amount of solder supplied to the side surfaces and the bottom 22 of the projection 21 and easily obtaining solder particles with higher accuracy.
Height H of the projection 21 2 The width D is not particularly limited, and may be, for example 22 The width D is preferably 10% or more, from the viewpoint of avoiding contact with the solder on the bottom portion 12 and easily obtaining solder particles with higher accuracy 22 More preferably, the width D is 25% or more 22 More than 50%. And the height H of the convex part 21 2 For example, it may be a width D 22 1000% or less, according to the prevention of the damage of the convex portion 11In addition, the width D is preferable from the viewpoint of further improving the recovery rate of the solder particles 22 Is 500% or less, more preferably the width D 22 Less than 300%.
Distance L between adjacent projections 21 2 The width D is not particularly limited, but may be, for example, the width D from the viewpoint of suppressing the formation of large-diameter particles due to contact and fusion of solder particles on the projections 21 22 Is preferably not less than 3%, and the width D is preferably set 22 Is 8% or more, more preferably the width D 22 More than 15%. And, the distance L between the adjacent convex portions 21 2 For example, it may be a width D 22 Is preferably 1000% or less, and the width D is preferably set to further improve the production efficiency of the solder particles 22 Is 500% or less, more preferably the width D 22 Less than 200%.
The shape of the cross section perpendicular to the height direction of the convex portions 11 and 21 is not particularly limited, and may be, for example, the shape shown in fig. 3. Fig. 3 (a) to (e) are views schematically showing examples of the shape of a cross section perpendicular to the height direction of the convex portion.
The material constituting the base 10 is not particularly limited, and is preferably a material having heat resistance that does not deteriorate at the melting temperature of the solder layer. The material constituting the substrate 10 may be, for example, an inorganic material such as silicon, various ceramics, glass, or stainless steel, or an organic material such as various resins.
The method for producing the substrate 10 is not particularly limited, and the substrate can be suitably produced by a known method (for example, photolithography) capable of forming the convex portion 11.
Next, a solder layer is formed on the convex portion of at least a part of the base body (solder layer forming step). As the solder material for forming the solder layer, a commercially available solder material can be used without particular limitation, and can be appropriately selected according to the desired characteristics of the solder particles, the method of forming the solder layer, and the like. For example, in the case of forming a solder layer by sputtering, a solder plate that can be used as a sputtering target is selected.
The solder material may comprise, for example, tin or a tin alloy. <xnotran> , In-Sn , in-Sn-Ag , sn-Au , sn-Bi , sn-Bi-Ag , sn-Ag-Cu , sn-Cu . </xnotran> Specific examples of these tin alloys include the following.
In-Sn (52% by mass In, 48% by mass Bi, melting point 118 ℃ C.)
In-Sn-Ag (20% by mass In, 77.2% by mass Sn77, 2.8% by mass Ag2.8 melting point 175 ℃ C.)
Sn-Bi (Sn 43 mass%, bi57 mass%, melting point 138 ℃ C.)
Sn-Bi-Ag (Sn 42 mass%, bi57 mass%, ag1 mass% melting point 139 ℃ C.), sn-Ag-Cu (Sn96.5 mass%, ag3 mass%, cu0.5 mass% melting point 217 ℃ C.)
Sn-Cu (Sn99.3 mass%, cu0.7 mass% melting point 227 ℃ C.)
Sn-Au (Sn21.0 mass%, au79.0 mass% melting point 278 ℃ C.)
The solder material may comprise indium or an indium alloy, for example. As the indium alloy, for example, an In-Bi alloy, an In-Ag alloy, or the like can be used. Specific examples of the indium alloy include the following.
In-Bi (In66.3 mass%, bi33.7 mass% melting point 72 ℃ C.)
In-Bi (In33.0 mass%, bi67.0 mass% melting point 109 ℃ C.)
In-Ag (In97.0 mass%, ag3.0 mass% melting point 145 ℃ C.)
The tin alloy or indium alloy can be selected as the solder material according to the application (temperature at the time of use) of the solder particles and the like. For example, in the case where solder particles intended to be used for fusing at low temperatures are to be obtained, in-Sn alloys or Sn-Bi alloys may be used, and In this case, solder particles that can be fused at 150 ℃ or lower can be obtained. When a solder material having a high melting point, such as an Sn-Ag-Cu alloy or an Sn-Cu alloy, is used, solder particles that can maintain high reliability can be obtained even after being left at a high temperature.
The solder material may further include one or more selected from Ag, cu, ni, bi, zn, pd, pb, au, P, and B. From the following viewpoint, ag or Cu may be contained in these elements. Namely, the following effects are exhibited: since the solder material contains Ag or Cu, solder particles having excellent bonding strength with the electrode, which can lower the melting point of the obtained solder particles to about 220 ℃, are obtained, and thus good conduction reliability can be obtained.
The Cu content of the solder material is, for example, 0.05 to 10 mass%, and may be 0.1 to 5 mass% or 0.2 to 3 mass%. When the Cu content is 0.05 mass% or more, solder particles that can achieve good solder connection reliability can be easily obtained. When the Cu content is 10 mass% or less, solder particles having a low melting point and excellent wettability are easily obtained, and as a result, the connection reliability of the joint portion by the solder particles is easily improved.
The Ag content of the solder material is, for example, 0.05 to 10 mass%, and may be 0.1 to 5 mass% or 0.2 to 3 mass%. When the Ag content is 0.05 mass% or more, solder particles that can achieve good solder connection reliability can be easily obtained. When the Ag content is 10 mass% or less, solder particles having a low melting point and excellent wettability are easily obtained, and as a result, the connection reliability of the joint portion by the solder particles is easily improved.
In the solder layer forming step, a solder layer is formed on each of the convex portions of the base body. In the solder layer forming step, the step of forming the solder layer on the entire convex portion of the base prepared in the preparation step may be performed, or the step of forming the solder layer on a part of the convex portion of the base prepared in the preparation step may be performed.
In the solder layer forming step, a method of forming the solder layer is not particularly limited. Examples of the method for forming the solder layer include plating, vapor deposition, sputtering, and spraying. Among these, sputtering is preferable from the viewpoint that the thickness of the solder layer can be strictly controlled and solder particles having a smaller particle size distribution can be easily obtained.
In the solder layer forming step, the amount of the solder layer to be formed is not particularly limited, and may be appropriately changed according to the desired size of the solder particles. By appropriately changing the amount of the solder layer formed on the convex portion, the size of the solder particles formed on the convex portion can be easily adjusted.
In the solder layer forming step, the solder layer may be formed only on the convex portions of the base body, or the solder layer may be formed on portions other than the convex portions of the base body. For example, in the solder layer forming step, the solder layer may be formed on the convex portion and the bottom portion of the base.
Fig. 4 is a cross-sectional view schematically showing an example of a state in which a solder layer 50 is formed on the convex portion 11 of the base 10. In the embodiment shown in fig. 4, a solder layer is formed only on the convex portion 11 of the base 10.
The solder layer is formed using the solder material, and may include at least one selected from the group consisting of tin, a tin alloy, indium, and an indium alloy. And, the solder layer may contain at least one selected from the group consisting of an In-Bi alloy, an In-Sn-Ag alloy, an Sn-Au alloy, an Sn-Bi-Ag alloy, an Sn-Ag-Cu alloy, and an Sn-Cu alloy.
Fig. 6 is a cross-sectional view schematically showing another example of a state in which a solder layer 50 is formed on the convex portion 11 of the base 10. In the embodiment shown in fig. 6, a solder layer 50 is formed on the convex portion 11 of the base 10, and a solder layer 51 is also formed on the bottom portion 12 of the base 10. In this embodiment, the amount of solder layer 50 formed on projection 11 is, for example, preferably 20% or more, more preferably 30% or more, further preferably 50% or more, and still further preferably 60% or more, relative to the total volume of the solder layer formed on the base (the total volume of solder layer 50 and solder layer 51).
Next, the solder layer formed on the convex portion is fused to form solder particles on the convex portion (fusing step). In the fusing step, the solder layer formed on the convex portion is coalesced by melting and is made spherical by surface tension, thereby forming solder particles.
As a method of melting the solder layer, there is a method of heating the solder layer to a temperature equal to or higher than the melting point of the solder material constituting the solder layer. The solder layer may not melt even when heated at a temperature equal to or higher than the melting point due to the influence of the oxide film, and may not wet and diffuse or may not coalesce even when melted. Therefore, it is preferable that the solder layer is exposed to a reducing atmosphere to remove the oxide film on the surface of the solder layer, and then the solder layer is heated to a temperature not lower than the melting point of the solder material. The melting of the solder layer is preferably performed in a reducing atmosphere. By melting the solder layer in a reducing atmosphere, the melting, wetting diffusion, and coalescence of the solder layer are more effectively performed.
The method of using a reducing atmosphere is not particularly limited as long as the above-described effects can be obtained, and examples thereof include a method using hydrogen gas, hydrogen radicals, formic acid gas, and the like. For example, the solder layer can be melted in a reducing atmosphere by using a hydrogen reduction furnace, a hydrogen radical reduction furnace, a formic acid reduction furnace, or these conveyor belt furnaces or continuous furnaces. These apparatuses can include a heating device, a chamber filled with an inert gas (nitrogen, argon, or the like), a mechanism for making the inside of the chamber vacuum, and the like in the furnace, and therefore, the control of the reducing gas is easier. Further, if the inside of the chamber can be made vacuum, the voids can be removed by reducing the pressure after melting and coalescing the solder layer, and solder particles having more excellent connection stability can be obtained.
The ranges (Profile) of the reduction, dissolution conditions, temperature, and adjustment of the atmosphere in the furnace of the solder layer can be appropriately set in consideration of the melting point, grain size, recess size, material of the substrate, and the like of the solder layer. For example, the solder particles can be obtained by inserting a base body having a solder layer formed on the convex portion into a furnace, evacuating the furnace, introducing a reducing gas to fill the furnace with the reducing gas, removing the oxide film on the surface of the solder layer, evacuating the furnace to remove the reducing gas, heating the furnace to a temperature equal to or higher than the melting point of the solder layer to dissolve and coalesce the solder layer, filling nitrogen gas into the furnace after forming solder particles on the convex portion, and returning the temperature in the furnace to room temperature. For example, the solder particles can be obtained by inserting the base body having the solder layer formed on the convex portion into a furnace, evacuating the furnace, introducing a reducing gas to fill the furnace with the reducing gas, heating the solder layer by a furnace heating heater to remove the oxide film on the surface of the solder layer, evacuating the furnace to remove the reducing gas, heating the furnace to a temperature higher than the melting point of the solder layer to dissolve and coalesce the solder layer, forming solder particles on the convex portion, filling nitrogen gas into the furnace, and returning the temperature in the furnace to room temperature. The reduction force is increased by heating the solder layer in a reducing atmosphere, and the surface oxide film of the solder layer is easily removed.
For example, the solder particles can be obtained by inserting the base body having the solder layer formed on the concave portion into a furnace, evacuating the furnace, introducing a reducing gas to fill the furnace with the reducing gas, heating the base body by a furnace heating heater to a temperature equal to or higher than the melting point of the solder layer, reducing the base body to remove the oxide film on the surface of the solder layer, dissolving and coalescing the solder layer to form solder particles on the convex portion, evacuating the furnace to remove the reducing gas, filling nitrogen gas after reducing the voids in the solder particles, and returning the temperature in the furnace to room temperature. In this case, since the rise and fall of the temperature in the furnace can be controlled only once, there is an advantage that the treatment can be performed in a short time.
After the solder particles are formed on the convex portions, a step of removing the surface oxide film that has not been completely removed by setting the inside of the furnace again to a reducing atmosphere may be added. Therefore, it is possible to reduce residues of the solder layer remaining without being fused, a part of the oxide film remaining without being fused, and the like.
When an atmospheric-pressure conveyor furnace is used, the substrate having the solder layer formed on the convex portion is placed on a conveyor belt and continuously passed through a plurality of zones, thereby obtaining solder particles. For example, the solder particles can be obtained by placing the base body having the solder layer formed on the convex portion on a conveyor belt set at a constant speed, passing the base body through a region filled with an inert gas such as nitrogen or argon at a temperature lower than the melting point of the solder layer, passing the base body through a region filled with a reducing gas such as formic acid gas at a temperature lower than the melting point of the solder layer to remove the surface oxide film of the solder layer, passing the base body through a region filled with an inert gas such as nitrogen or argon at a temperature higher than the melting point of the solder layer to melt and coalesce the solder layer, and passing the base body through a cooling region filled with an inert gas such as nitrogen or argon. For example, the solder particles can be obtained by mounting the base body having the solder layer formed on the convex portion on a conveyor belt set at a constant speed, passing the base body through a region filled with an inert gas such as nitrogen or argon at a temperature equal to or higher than the melting point of the solder layer, then passing the base body through a region where a reducing gas such as formic acid gas at a temperature equal to or higher than the melting point of the solder layer is present, removing the surface oxide film of the solder layer, melting and coalescing the oxide film, and then passing the base body through a cooling zone filled with an inert gas such as nitrogen or argon. The conveyor furnace can perform the treatment under atmospheric pressure, and therefore, the film-like material can be continuously treated in a roll-to-roll manner. For example, a continuous roll product of a base body in which a solder layer is formed on a convex portion is manufactured, an unwinder is provided on an inlet side of a belt furnace, a winder is provided on an outlet side of the belt furnace, and the base body is conveyed at a constant speed and passed through each region in the belt furnace, so that the solder layer formed on the convex portion can be fused.
The formed solder particles can be transported and stored in a state of being formed on the convex portion of the base. The substrate in a state where the solder particles are formed on the convex portions can be appropriately treated as a substrate with solder particles. The base body with solder particles comprises a base body having a plurality of projections and a plurality of solder particles arranged on the projections of the base body. The solder particles may have an average particle diameter of 100nm or more and less than 1 μm, and the solder particles may have a C.V. value of 20% or less. The formed solder particles can be recovered from the convex portions. The resin material may be disposed so as to face the convex portions of the base body, so that the solder particles on the convex portions are transferred to the resin material. In this case, if the convex portions are regularly arranged, the solder particles can be regularly arranged on the resin material.
Fig. 5 is a cross-sectional view schematically showing an example of a state in which solder particles are formed on the convex portions of the base. The base body 100 with solder particles shown in fig. 5 is provided with the base body 10 with the solder layer 50 formed shown in fig. 4 at the fusing step. In the solder particle-attached base 100, the solder particles 1 are formed on the convex portions 11 of the base 10 having the plurality of convex portions 11.
Fig. 7 is a cross-sectional view schematically showing another example of a state where solder particles are formed on the convex portions of the base. The base body 110 with solder particles shown in fig. 7 may be provided with the base body 10 with the solder layer 50 and the solder layer 51 formed thereon shown in fig. 6 in the fusing step. In the solder particle-attached base body 110, the solder particles 1 are formed on the convex portions 11 of the base body 10 having the plurality of convex portions 11. In the solder particle-attached base 110, the solder particles 2 are formed from the solder layer 51 on the bottom portions 12 between the convex portions 11. The solder particles 2 are not necessarily limited to exhibit a small particle size distribution, and therefore, it is preferable to recover or transfer only the solder particles 1 in the present embodiment. The solder particles 2 are fixed to the bottom 12 of the base 10 and are present at a position lower than the solder particles 1 on the projections 11. Therefore, for example, the resin material is disposed so as to face the convex portions 11 of the base 10, and the solder particles 1 on the convex portions 11 are transferred to the resin material, so that only the solder particles 1 can be collected.
According to the manufacturing method of the present embodiment, solder particles having a uniform size can be formed regardless of the material and shape of the solder material. For example, indium-based solder can be deposited by plating, but is difficult to deposit in a particulate form and is flexible and difficult to handle. However, in the manufacturing method of the present embodiment, indium solder particles having a uniform particle diameter can be easily manufactured by using an indium solder plate as a raw material. Further, the formed solder particles can be handled in a state of being formed on the convex portion of the base body, and therefore, the solder particles can be transported and stored without being deformed. Further, the formed solder particles are formed only on the projections of the base, and therefore, they can be easily taken out, and the solder particles can be recovered, subjected to surface treatment, and the like without being deformed.
Even if the solder material has a large variation in size and particle size distribution and a deformed shape, the solder material can be used as a raw material for the production method of the present embodiment if the solder layer can be formed on the convex portion by a method such as sputtering, plating, or spraying.
In the manufacturing method of the present embodiment, the shape of the convex portion of the base can be freely designed by photolithography, imprinting, machining, electron beam machining, radiation machining, or the like. Since the size of the solder particles depends on the amount of the solder layer formed on the convex portions, the size of the solder particles can be freely designed according to the design of the convex portions in the manufacturing method of the present embodiment.
(solder particle)
The solder particles of the present embodiment have an average particle diameter of 100nm or more and 30 μm or less and a c.v. value of 20% or less, and preferably have an average particle diameter of 100nm or more and less than 1 μm and a c.v. value of 20% or less. Such solder particles have both a small average particle diameter and a narrow particle size distribution, and can be suitably used as conductive particles suitable for an anisotropic conductive material having high conductive reliability and insulation reliability. The solder particles of the present embodiment are produced by the above-described production method.
The average particle diameter of the solder particles is not particularly limited if it is within the above range, and may be, for example, 30 μm or less, 15 μm or less, 10 μm or less, 5 μm or less, 3 μm or less, or 2 μm or less, and preferably less than 1 μm. The average particle size of the solder particles may be, for example, 100nm or more, or 200nm or more, 300nm or more, 400nm or 500nm or more.
The average particle diameter of the solder particles can be measured by various methods in accordance with the size. For example, a dynamic light scattering method, a laser diffraction method, a centrifugal sedimentation method, an electrical detection band method, a resonance mass measurement method, or the like can be used. In addition, a method of measuring the particle size from an image obtained by an optical microscope, an electron microscope, or the like can be used. Specific examples of the apparatus include a flow particle image analyzer, a mackerel granulometer (MICROTRAC), and a coulter counter.
From the viewpoint of achieving more excellent conductive reliability and insulation reliability, the c.v. value of the solder particles is preferably 20% or less, more preferably 10% or less, further preferably 7% or less, and particularly preferably 5% or less. The lower limit of the c.v. value of the solder particles is not particularly limited. For example, the c.v. value of the solder particles may be 1% or more, or may be 2% or more.
The c.v. value of the solder particles is calculated by multiplying the value obtained by dividing the standard deviation of the particle diameter determined by the method by the average particle diameter by 100.
The solder particles may have a flat surface portion formed on a part of the surface, and in this case, the surface other than the flat surface portion is preferably a spherical crown shape. That is, the solder particles may have a planar portion and a spherical crown-shaped curved surface portion. The ratio (A/B) of the diameter A of the flat surface portion to the diameter B of the solder particles may be, for example, more than 0.01 and less than 1.0 (0.01 < A/B < 1.0), or may be 0.1 to 0.9. Since the solder particles have the planar portions, the arrangement of the solder particles is improved and the workability is improved. Specifically, when solder particles are arranged on an object to be connected by solder particles such as electrodes, the solder particles are easily arranged at a predetermined position due to the flat portion, and the solder particles are effectively prevented from moving from the predetermined position due to vibration, wind, external force, static electricity, and the like. Further, when the member on which the solder particles are arranged is inclined, the solder particles are less likely to move due to gravity than, for example, spherical solder particles having no flat portion.
In the above manufacturing method, solder particles are formed on the convex portions of the base. In this case, the flat surface portion may be formed on a contact surface between the solder particle and the top portion of the convex portion.
When a quadrangle circumscribing the projection image of the solder particles is formed by two pairs of parallel lines, the ratio of Y to X (Y/X) may be greater than 0.8 and less than 1.0 (0.8 < Y/X < 1.0), or may be 0.9 or more and less than 1.0, where X and Y are the distances between the opposing sides (Y < X). Such solder particles can be referred to as particles that are closer to spherical. Such solder particles can be easily obtained by the manufacturing method of the present embodiment.
Since the solder particles are close to spherical balls, for example, when a plurality of electrodes facing each other are electrically connected to each other via the solder particles, unevenness is less likely to occur in the contact between the solder particles and the electrodes, and stable connection tends to be obtained. In addition, when a conductive film or resin in which solder particles are dispersed in a resin material is produced, high dispersibility tends to be obtained, and dispersion stability during production tends to be obtained. In addition, when a film or paste in which solder particles are dispersed in a resin material is used for connecting between electrodes, even if the solder particles rotate in the resin, if the solder particles are in a spherical shape, the projected areas of the solder particles are close to each other when viewed in a projected image. Therefore, when the electrodes are connected to each other, there is a tendency that a small variation is easily obtained and stable electrical connection is obtained.
Fig. 8 is a diagram showing distances X and Y between opposing sides (where Y < X) when a square circumscribing a projection image of solder particles is made of two pairs of parallel lines. For example, a projection image is obtained by observing an arbitrary particle with a scanning electron microscope. Two pairs of parallel lines are drawn for the obtained projection image, one pair of parallel lines is arranged at a position where the distance between the parallel lines is the smallest, and the other pair of parallel lines is arranged at a position where the distance between the parallel lines is the largest, and the Y/X of the particle is obtained. This operation was performed on 300 solder particles to calculate an average value, which was set as Y/X of the solder particles.
The solder particles may comprise tin or a tin alloy. <xnotran> , In-Sn , in-Sn-Ag , sn-Au , sn-Bi , sn-Bi-Ag , sn-Ag-Cu , sn-Cu . </xnotran> Specific examples of these tin alloys include the following.
In-Sn (52% by mass In, 48% by mass Bi, melting point 118 ℃ C.)
In-Sn-Ag (20% by mass In, 77.2% by mass Sn77, 2.8% by mass Ag2.8 melting point 175 ℃ C.)
Sn-Bi (Sn 43 mass%, bi57 mass%, melting point 138 ℃ C.)
Sn-Bi-Ag (Sn 42 mass%, bi57 mass%, ag1 mass% melting point 139 ℃ C.), sn-Ag-Cu (Sn96.5 mass%, ag3 mass%, cu0.5 mass% melting point 217 ℃ C.)
Sn-Cu (Sn99.3 mass%, cu0.7 mass% melting point 227 ℃ C.)
Sn-Au (Sn21.0 mass%, au79.0 mass% melting Point 278 ℃ C.)
The solder particles may comprise indium or an indium alloy. As the indium alloy, for example, an In-Bi alloy, an In-Ag alloy, or the like can be used. Specific examples of the indium alloy include the following.
In-Bi (In66.3 mass%, bi33.7 mass% melting point 72 ℃ C.)
In-Bi (In33.0 mass%, bi67.0 mass% melting point 109 ℃ C.)
In-Ag (In97.0% by mass, ag3.0% by mass melting point 145 ℃ C.)
The tin alloy or indium alloy can be selected according to the use (temperature at the time of use) of the solder particles. For example, when solder particles are used for welding at low temperatures, an In-Sn alloy or an Sn-Bi alloy can be used, and In this case, welding can be performed at 150 ℃ or lower. When a material having a high melting point, such as an Sn-Ag-Cu alloy or an Sn-Cu alloy, is used, high reliability can be maintained even after the material is left at a high temperature.
The solder particles may include one or more selected from Ag, cu, ni, bi, zn, pd, pb, au, P, and B. From the following viewpoint, ag or Cu may be contained in these elements. That is, since the solder particles contain Ag or Cu, the melting point of the solder particles can be reduced to about 220 ℃, and the bonding strength with the electrode is further improved, so that more favorable conduction reliability is easily obtained.
The Cu content of the solder particles is, for example, 0.05 to 10 mass%, and may be 0.1 to 5 mass% or 0.2 to 3 mass%. When the Cu content is 0.05 mass% or more, more favorable solder connection reliability can be easily achieved. When the Cu content is 10 mass% or less, solder particles having a low melting point and excellent wettability are likely to be formed, and as a result, the connection reliability of the joint portion by the solder particles is likely to be good.
The Ag content of the solder particles is, for example, 0.05 to 10 mass%, and may be 0.1 to 5 mass% or 0.2 to 3 mass%. When the Ag content is 0.05 mass% or more, more favorable solder connection reliability can be easily achieved. When the Ag content is 10 mass% or less, solder particles having a low melting point and excellent wettability are likely to be formed, and as a result, the connection reliability of the joint portion by the solder particles is likely to be improved.
The use of the solder particles is not particularly limited, and for example, the solder particles can be suitably used as conductive particles for an anisotropic conductive material. Further, the following applications can be suitably used: the use of electrically connecting electrodes to each other, such as a ball grid array connection method (BGA connection) widely used for mounting a semiconductor integrated circuit; and sealing and tubing of MEMS and like components, brazing, spacers for height and gap control, and the like. That is, the solder particles can be used for conventional uses in which solder has been conventionally used.
Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.
Examples
The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.
< example 1 >
(step a 1) preparation of the substrate
A substrate (polyimide film, thickness 50 μm) having a plurality of projections with a top diameter of 0.15 μm, a bottom diameter of 0.15 μm, and a height of 0.13 μm was prepared. The plurality of projections were regularly arranged at intervals of 0.15 μm.
(step b 1) formation of solder layer
The substrate having the plurality of projections obtained in step a1 was placed in a sputtering apparatus (manufactured by ARIOS inc.), and after evacuation, argon gas was added to the apparatus, and the inside of the apparatus was set to an argon gas atmosphere of 1 Pa. Then, sputtering was performed only for the time shown in table 1 under the following conditions, thereby forming a solder layer.
(device Condition)
Target … … Sn-Bi solder plate (melting point 139 ℃ C.)
Input power … … W
(step c 1) formation of solder particles
The substrate having the solder layer obtained in step b1 was placed in a formic acid radical reduction furnace (SHINKO SEIKI co., ltd., manufactured reflow apparatus), and after evacuation, formic acid mixed with nitrogen gas (formic acid content 4%) was introduced into the furnace to fill the furnace. Then, the inside of the furnace was adjusted to 120 ℃ and reduction treatment was performed for 5 minutes. Then, after heating to 180 ℃, the gas inside the furnace was removed by vacuum-pumping, and nitrogen gas was introduced into the furnace to return to atmospheric pressure, and then the temperature inside the furnace was lowered to room temperature, whereby solder particles were formed.
< evaluation of solder particles >
A base having the solder particles obtained in step c1 is fixed to the conductive tape fixed to the surface of the base for SEM observation. Then, platinum sputtering was performed at 20mA for 60 seconds. The diameters of 200 core-shell solder particles were measured by SEM, and the average particle diameter and c.v. value were calculated. The results are shown in table 1.
< examples 2 to 12 >
Solder particles were produced and evaluated in the same manner as in example 1, with the top diameter, bottom diameter, height, spacing, sputtering time, and material shown in table 1. The results are shown in table 1. Fig. 12 shows an SEM image of the solder particles obtained in example 2.
< examples 13 to 17 >
Solder particles were produced and evaluated in the same manner as in example 1 except that the following step c2 was performed instead of step c1, and the top diameter, bottom diameter, height, interval, sputtering time, and material described in table 1 were used. The results are shown in table 1. An SEM image of the substrate prepared in example 13 is shown in fig. 9, an SEM image of the shape in which the solder layer is formed on the substrate is shown in fig. 10, and an SEM image of the shape in which the solder particles are formed is shown in fig. 11.
(step c 2) formation of solder particles
The substrate having the solder layer obtained in step b1 is placed in a hydrogen radical reduction furnace (SHINKO SEIKI co., ltd. Manufacturing, plasma reflow apparatus), and after evacuation, hydrogen gas is introduced into the furnace to fill the furnace with hydrogen gas. Then, the inside of the furnace was adjusted to 130 ℃, and hydrogen radicals were irradiated for 5 minutes. Then, hydrogen gas in the furnace was removed by vacuum evacuation, after heating to 165 ℃, nitrogen gas was introduced into the furnace to return to atmospheric pressure, and then the temperature in the furnace was lowered to room temperature, whereby solder particles were formed.
< comparative example 1 >
Sn-Bi solder fine particles (manufactured by 5N Plus Inc., melting point 139 ℃, type 8, D) 50＝ 3.0 μm, C.V. value 42%) was divided into 5 portions per 100g, and each was immersed in distilled water, followed by ultrasonic dispersion and standingThe solder fine particles floating in the supernatant liquid are recovered. This operation was repeated to recover a total of 1g of solder fine particles. The average particle diameter and c.v. value of the obtained solder fine particles are shown in table 1.
< comparative example 2 >
Solder particles were produced and evaluated in the same manner as in example 2, except that a smooth substrate (polyimide film, thickness 50 μm) having no convex portion was prepared. The results are shown in table 1. Fig. 13 shows an SEM image of the obtained solder particles.
[ Table 1]
Description of the symbols
1-solder particles, 10-matrix, 11, 21-protrusions, 12, 22-bottoms, 50-solder layer, 100, 110-matrix with solder particles.
Claims (14)
1. A method of manufacturing solder particles, comprising:
a preparation step of preparing a base having a plurality of projections;
a solder layer forming step of forming a solder layer on the convex portion of at least a part of the base body; and
and a fusing step of fusing the solder layer formed on the convex portion to form solder particles on the convex portion.
2. The method for producing solder particles according to claim 1,
the convex part is columnar or frustum-shaped.
3. The method for producing solder particles according to claim 1 or 2,
the base body has a first surface provided with a plurality of projections and a bottom portion formed between the projections,
the proportion of the projection area of the bottom in the projection area of the first surface is more than 8%.
4. The method for producing solder particles according to any one of claims 1 to 3,
in the solder layer forming step, the solder layer is formed on the convex portion by at least one method selected from the group consisting of plating, evaporation, sputtering, and spraying.
5. The method for producing solder particles according to any one of claims 1 to 4,
before the fusing step, a reducing step of exposing the solder layer formed on the convex portion to a reducing atmosphere is further included.
6. The method for producing solder particles according to any one of claims 1 to 5,
in the fusing step, the solder layer formed on the convex portion is fused under a reducing atmosphere.
7. The method for producing solder particles according to any one of claims 1 to 6,
the solder layer includes at least one selected from the group consisting of tin, tin alloy, indium, and indium alloy.
8. The method for manufacturing solder particles according to claim 7,
the solder layer contains at least one selected from the group consisting of an In-Bi alloy, an In-Sn-Ag alloy, an Sn-Au alloy, an Sn-Bi-Ag alloy, an Sn-Ag-Cu alloy, and an Sn-Cu alloy.
9. Solder particles having an average particle diameter of 100nm or more and less than 1 μm and a C.V. value of 20% or less.
10. The solder particle according to claim 9,
when a quadrangle circumscribed to the projection image of the solder particles is formed by two pairs of parallel lines, X and Y satisfy the following expression when the distance between the opposite sides is X and Y < X,
0.8＜Y/X＜1.0。
11. the solder particle according to claim 9 or 10, comprising at least one selected from the group consisting of tin, a tin alloy, indium, and an indium alloy.
12. The solder particle according to any one of claims 9 to 11, comprising at least one selected from the group consisting of an In-Bi alloy, an In-Sn-Ag alloy, an Sn-Au alloy, an Sn-Bi-Ag alloy, an Sn-Ag-Cu alloy, and an Sn-Cu alloy.
13. A substrate with solder particles, comprising:
a base having a plurality of projections; and a plurality of solder particles disposed on the convex portion of the base.
14. The solder particle-bearing substrate according to claim 13,
the average particle diameter of the solder particles is more than 100nm and less than 1 μm, and the C.V. value of the solder particles is less than 20%.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2020068390 | 2020-04-06 | ||
| JP2020-068390 | 2020-04-06 | ||
| PCT/JP2021/014656 WO2021206096A1 (en) | 2020-04-06 | 2021-04-06 | Solder particles, production method for solder particles, and substrate with solder particles |
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| CN115362044A true CN115362044A (en) | 2022-11-18 |
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| CN202180026545.8A Pending CN115362044A (en) | 2020-04-06 | 2021-04-06 | Solder particle, method for producing solder particle, and substrate with solder particle |
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| Country | Link |
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| JP (1) | JPWO2021206096A1 (en) |
| CN (1) | CN115362044A (en) |
| TW (1) | TW202146679A (en) |
| WO (1) | WO2021206096A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5411602A (en) * | 1994-02-17 | 1995-05-02 | Microfab Technologies, Inc. | Solder compositions and methods of making same |
| US6000603A (en) * | 1997-05-23 | 1999-12-14 | 3M Innovative Properties Company | Patterned array of metal balls and methods of making |
| US6426564B1 (en) * | 1999-02-24 | 2002-07-30 | Micron Technology, Inc. | Recessed tape and method for forming a BGA assembly |
| US6784086B2 (en) * | 2001-02-08 | 2004-08-31 | International Business Machines Corporation | Lead-free solder structure and method for high fatigue life |
| JP5478193B2 (en) * | 2009-09-01 | 2014-04-23 | Ｄｏｗａホールディングス株式会社 | Solder powder manufacturing method |
| CN103221164B (en) * | 2010-11-18 | 2016-06-15 | 同和控股（集团）有限公司 | The manufacture method of solder powder and solder powder |
| JP7452419B2 (en) * | 2018-06-26 | 2024-03-19 | 株式会社レゾナック | Solder particles and method for producing solder particles |
| CN112313032A (en) * | 2018-06-26 | 2021-02-02 | 昭和电工材料株式会社 | Anisotropic conductive film, method for producing same, and method for producing connection structure |
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2021
- 2021-04-06 JP JP2022514090A patent/JPWO2021206096A1/ja active Pending
- 2021-04-06 WO PCT/JP2021/014656 patent/WO2021206096A1/en active Application Filing
- 2021-04-06 TW TW110112371A patent/TW202146679A/en unknown
- 2021-04-06 CN CN202180026545.8A patent/CN115362044A/en active Pending
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| TW202146679A (en) | 2021-12-16 |
| WO2021206096A1 (en) | 2021-10-14 |
| JPWO2021206096A1 (en) | 2021-10-14 |
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