WO2015118613A1 - Niボール、Ni核ボール、はんだ継手、はんだペースト、およびフォームはんだ - Google Patents
Niボール、Ni核ボール、はんだ継手、はんだペースト、およびフォームはんだ Download PDFInfo
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- WO2015118613A1 WO2015118613A1 PCT/JP2014/052571 JP2014052571W WO2015118613A1 WO 2015118613 A1 WO2015118613 A1 WO 2015118613A1 JP 2014052571 W JP2014052571 W JP 2014052571W WO 2015118613 A1 WO2015118613 A1 WO 2015118613A1
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- 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
-
- 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
- B22F1/06—Metallic powder characterised by the shape of the particles
- B22F1/065—Spherical particles
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- 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
- B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
- B22F1/107—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material containing organic material comprising solvents, e.g. for slip casting
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- 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
- B22F1/16—Metallic particles coated with a non-metal
-
- 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
- B23K35/02—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape
- B23K35/0222—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape for use in soldering, brazing
- B23K35/0244—Powders, particles or spheres; Preforms made therefrom
- B23K35/025—Pastes, creams, slurries
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- 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
- B23K35/3033—Ni as the principal constituent
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/04—Making non-ferrous alloys by powder metallurgy
- C22C1/0425—Copper-based alloys
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C19/00—Alloys based on nickel or cobalt
- C22C19/03—Alloys based on nickel or cobalt based on nickel
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/10—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of nickel or cobalt or alloys based thereon
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- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D7/00—Electroplating characterised by the article coated
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- 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
- B22F2301/00—Metallic composition of the powder or its coating
- B22F2301/15—Nickel or cobalt
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- 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
- B22F2302/00—Metal Compound, non-Metallic compound or non-metal composition of the powder or its coating
- B22F2302/45—Others, including non-metals
-
- 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
- B23K35/262—Sn as the principal constituent
-
- 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
- B23K35/36—Selection of non-metallic compositions, e.g. coatings, fluxes; Selection of soldering or welding materials, conjoint with selection of non-metallic compositions, both selections being of interest
- B23K35/3612—Selection of non-metallic compositions, e.g. coatings, fluxes; Selection of soldering or welding materials, conjoint with selection of non-metallic compositions, both selections being of interest with organic compounds as principal constituents
-
- 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
- B23K35/36—Selection of non-metallic compositions, e.g. coatings, fluxes; Selection of soldering or welding materials, conjoint with selection of non-metallic compositions, both selections being of interest
- B23K35/3612—Selection of non-metallic compositions, e.g. coatings, fluxes; Selection of soldering or welding materials, conjoint with selection of non-metallic compositions, both selections being of interest with organic compounds as principal constituents
- B23K35/3616—Halogen compounds
-
- 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
- B23K35/36—Selection of non-metallic compositions, e.g. coatings, fluxes; Selection of soldering or welding materials, conjoint with selection of non-metallic compositions, both selections being of interest
- B23K35/362—Selection of compositions of fluxes
Definitions
- the present invention relates to Ni balls, Ni core balls, solder joints, solder paste, and foam solder.
- the electronic components to be mounted have been rapidly downsized.
- the electronic component uses a ball grid array (hereinafter referred to as “BGA”) in which electrodes are provided on the back surface. .
- BGA ball grid array
- An electronic component to which BGA is applied includes, for example, a semiconductor package.
- a semiconductor package a semiconductor chip having electrodes is sealed with a resin.
- Solder bumps are formed on the electrodes of the semiconductor chip. This solder bump is formed by joining a solder ball to an electrode of a semiconductor chip.
- a semiconductor package to which BGA is applied is mounted on a printed board by bonding solder bumps melted by heating and conductive lands of the printed board. Further, in order to meet the demand for further high-density mounting, three-dimensional high-density mounting in which semiconductor packages are stacked in the height direction has been studied.
- solder bump is being studied in which a solder paste is used to electrically join a Ni ball or a Ni core ball in which the surface of the Ni ball is coated with solder plating on the electrode of an electronic component.
- Solder bumps formed using Ni balls or Ni core balls are formed by Ni balls that do not melt at the melting point of the solder when the weight of the semiconductor package is applied to the solder bumps when the electronic component is mounted on a printed circuit board. Can support. Therefore, the solder bump is not crushed by the weight of the semiconductor package.
- Patent Document 1 is cited as a related technique.
- the Ni ball is formed by melting the Ni material at a high temperature and spraying the liquid molten Ni at a high speed from the nozzle, thereby rapidly cooling the mist-like molten Ni to room temperature (for example, 25 ° C.).
- a metal melt is introduced into a spray tank in a helium gas atmosphere from a nozzle provided at the bottom of a carbon crucible, and a H 2 / He mixed gas is ejected from a gas nozzle provided near the tip of the carbon crucible.
- a method of forming a ball such as Ni by gas atomization, in which a metal melt is atomized to produce ultrafine particles is described.
- Ni balls when Ni balls are manufactured by rapid cooling, Ni crystal grains are formed in an instant, and Ni balls are formed by fine crystal grains before the crystal grains grow large. Since Ni balls formed with fine crystal grains are hard and have a large Vickers hardness, there is a problem that durability against external stress is lowered and drop impact resistance is deteriorated. Therefore, a Ni ball used for mounting a semiconductor chip is required to have a certain softness, that is, a Vickers hardness of a certain value or less.
- Ni balls having a certain softness In order to produce Ni balls having a certain softness, it is customary to increase the purity of Ni. This is because when the number of impurity elements functioning as crystal nuclei in the Ni balls decreases, the crystal grains grow larger, and as a result, the Vickers hardness of the Ni balls decreases. However, when the purity of the Ni ball is increased, there is a problem that the sphericity of the Ni ball is lowered instead of reducing the Vickers hardness of the Ni ball.
- Patent Document 1 a method for manufacturing a Ni ball is described, but there is no description of a Ni ball in consideration of characteristics of both Vickers hardness and sphericity.
- the present invention provides Ni balls, Ni core balls, solder joints, solder pastes, and foams that are excellent in drop impact resistance and can suppress the occurrence of poor bonding or the like.
- the purpose is to provide solder.
- the inventors selected Ni balls. It has been found that when the Vickers hardness of the Ni ball is 20 HV or more and 90 HV or less, a preferable Ni ball for solving the problems of the present invention can be obtained. Furthermore, it has been found that by promoting the crystal growth of the Ni balls, Ni balls in the range of 20 HV or more and 90 HV or less can be obtained more efficiently, and a mass production effect can be obtained.
- the “annealing process” is employed as a means for promoting the crystal growth of the Ni balls will be described. However, this annealing process is not necessarily a necessary step, and other means are adopted to adopt the Ni process. It is also possible to promote the crystal growth of the ball.
- the present invention is as follows. (1) Ni balls having a purity of 99.9% or more and 99.995% or less, a sphericity of 0.90 or more, and a Vickers hardness of 20HV or more and 90HV or less.
- the U content is 5 ppb or less, the Th content is 5 ppb or less, the total content of at least one of Pb and Bi is 1 ppm or more, and the ⁇ dose is 0.0200 cph / cm 2.
- the Ni ball according to (1) which is:
- a Ni core ball comprising the Ni ball according to any one of (1) to (3) above and a solder layer covering the Ni ball.
- Ni core ball provided with the Ni ball according to any one of the above (1) to (3), and a plating layer comprising one or more elements selected from Ni, Fe and Co covering the Ni ball .
- Ni core ball according to (6) further including a solder layer covering the plating layer.
- Ni core ball according to (5) to (7) above having a sphericity of 0.90 or more.
- the solder layer covering the plating layer has a U content of 5 ppb or less, a Th content of 5 ppb or less, and a total content of at least one of Pb and Bi is 1 ppm or more.
- the Ni core ball according to any one of (5) to (7), wherein the ⁇ dose is 0.0200 cph / cm 2 or less.
- the Vickers hardness of the Ni ball is 20 HV or more and 90 HV or less, the drop impact resistance can be improved and an appropriate space between the substrates can be maintained.
- the sphericity of the Ni ball is 0.90 or more, self-alignment can be ensured when the Ni ball is mounted on the electrode, and variation in the height of the Ni ball can be suppressed.
- FIG. 1 is a diagram showing a configuration example of an electronic component using Ni balls according to the present invention.
- FIG. 2 is a diagram showing the relationship between temperature and time during the annealing process.
- the unit (ppm, ppb, and%) relating to the composition of the Ni ball represents a ratio (mass ppm, mass ppb, and mass%) to the mass of the Ni ball unless otherwise specified.
- FIG. 1 shows an example of the configuration of an electronic component 60 in which a semiconductor chip 10 is mounted on a printed circuit board 40 using Ni balls 20 according to the present invention.
- the Ni ball 20 is mounted on the electrode 11 of the semiconductor chip 10 via the solder paste 12.
- the structure in which the Ni ball 20 is mounted on the electrode 11 of the semiconductor chip 10 is referred to as a solder bump 30.
- a solder paste 42 is printed on the electrode 41 of the printed board 40.
- the solder bumps 30 of the semiconductor chip 10 are bonded onto the electrodes 41 of the printed circuit board 40 via the solder paste 42.
- a structure in which the solder bump 30 is mounted on the electrode 41 of the printed circuit board 40 is referred to as a solder joint 50.
- the Ni ball 20 according to the present invention has a purity of 99.9% or more and 99.995% or less, a sphericity of 0.90 or more, and a Vickers hardness of 20HV or more and 90HV or less. .
- the drop impact resistance can be improved by setting the Vickers hardness of the Ni ball to 90 HV or less, and an appropriate space between the substrates can be maintained by setting the Vickers hardness to 20 HV or more.
- the sphericity of the Ni ball 20 to 0.90 or more, it is possible to ensure self-alignment when the Ni ball 20 is mounted on the electrode 11 or the like of the semiconductor chip 10, and the Ni ball 20 is soldered. Since it does not melt at the temperature, it is possible to suppress variations in height in the solder joint 50. Thereby, the joining defect of the semiconductor chip 10 and the printed circuit board 40 can be prevented reliably.
- bowl 20 is demonstrated.
- bowl which concerns on this invention is 90HV or less. This is because when the Vickers hardness exceeds 90 HV, durability against external stress is reduced, drop impact resistance is deteriorated, and cracks are easily generated. In addition, when an auxiliary force such as pressurization is applied when forming bumps or joints for three-dimensional mounting, if a hard Ni ball is used, the electrodes may be crushed. Furthermore, when the Vickers hardness of the Ni ball 20 exceeds 90 HV, the crystal grains become smaller than a certain level, leading to deterioration of electrical conductivity.
- the Ni balls 20 having a Vickers hardness of 90 HV or less are produced by promoting crystal growth of the produced Ni balls 20.
- a slow cooling process is provided instead of the conventional rapid cooling when the Ni balls 20 are formed.
- a drop-type apparatus as a manufacturing apparatus for forming the Ni ball 20
- a very high tower height is required for slow cooling, which is difficult to realize. This can be dealt with by providing a slow cooling process that slows the cooling rate or sets the transport distance longer.
- the Vickers hardness of the Ni ball according to the present invention must be at least larger than the Vickers hardness of the solder ball of 10 to 20 HV, preferably 20 HV or more.
- the Vickers hardness of the Ni ball is less than 20 HV, the Ni ball itself is deformed (collapsed) by its own weight such as a semiconductor chip in three-dimensional mounting, and an appropriate space (standoff height) between the substrates cannot be maintained.
- the pitch of the electrodes 41 and the like can be reduced by setting the Vickers hardness of the Ni balls 20 to 20 HV or higher.
- U and Th are radioactive elements, and it is necessary to suppress their contents in order to suppress soft errors.
- the U and Th contents need to be 5 ppb or less in order to make the ⁇ dose of the Ni balls 20 0.0200 cph / cm 2 or less. Further, from the viewpoint of suppressing soft errors in current or future high-density mounting, the contents of U and Th are preferably 2 ppb or less, respectively.
- Ni ball 20 constituting the present invention preferably has a purity of 99.9% or more and 99.995% or less.
- the purity of the Ni ball 20 is within this range, a sufficient amount of crystal nuclei for increasing the sphericity of the Ni ball 20 can be secured in the molten Cu. The reason why the sphericity is increased will be described in detail as follows.
- the Ni ball 20 When the Ni ball 20 is manufactured, the Ni material formed into small pieces of a predetermined shape is melted by heating, and the molten Ni becomes spherical due to surface tension, which solidifies into the Ni ball 20. In the process where the molten Ni solidifies from the liquid state, crystal grains grow in the spherical molten Ni. At this time, if there are many impurity elements, the impurity elements serve as crystal nuclei and growth of crystal grains is suppressed. Accordingly, the spherical molten Ni becomes Ni balls 20 having high sphericity due to the fine crystal grains whose growth is suppressed.
- Ni balls 20 have low sphericity.
- Possible impurity elements include Sb, Cu, Bi, Zn, Fe, Al, As, Cd, Sn, Pb, Ag, In, Au, P, S, Mg, Ti, Co, Mn, U, and Th. .
- the lower limit of purity is not particularly limited, but is preferably 99.9% or more from the viewpoint of suppressing the ⁇ dose and suppressing deterioration of the electrical conductivity and thermal conductivity of the Ni ball 20 due to the decrease in purity.
- the ⁇ dose can be reduced without increasing the purity more than necessary.
- Ni has a higher melting point than Sn, and the heating temperature during production is higher for Ni.
- radioactive elements represented by 210 Po, 210 Pb, and 210 Bi are volatilized. Among these radioactive elements, 210 Po is particularly volatile.
- ⁇ dose 0.0200 cph / cm 2 or less
- the ⁇ dose of the Ni balls 20 constituting the present invention is 0.0200 cph / cm 2 or less, preferably 0.0020 cph / cm 2 or less, more preferably 0. .0010 cph / cm 2 or less.
- This is an ⁇ dose that does not cause a soft error in high-density mounting of electronic components.
- Ni balls are manufactured by heating and melting a Ni material to 1500 ° C. or higher, the content of radioactive elements such as 210 Po that emits ⁇ rays is sufficiently reduced by volatilization, The alpha rays were thought not to cause soft errors.
- Ni balls with low ⁇ rays are reduced to such an extent that soft errors are not caused by the conventional manufacturing conditions of Ni balls.
- 210 Po has a boiling point of 962 ° C., and it seems that it volatilizes sufficiently to the extent that soft errors do not occur when heated to 1500 ° C. or higher.
- the temperature at 210 Po is always sufficiently reduced. It is not certain whether Ni balls with low ⁇ rays can be obtained by manufacturing conventional Ni balls.
- the Ni ball 20 in addition to the process normally performed in order to manufacture the Ni ball
- the ⁇ dose is preferably 0.0020 cph / cm 2 or less, more preferably 0.0010 cph / cm 2 or less, from the viewpoint of suppressing soft errors in further high-density mounting. It should be noted that the ⁇ dose of the Ni ball 20 does not increase by providing an annealing process or a slow cooling process for reducing the Vickers hardness of the Ni ball 20.
- the content of at least one of Pb and Bi is 1 ppm or more in total.
- the Ni ball 20 constituting the present invention has Sb, Cu, Bi, Zn, Fe, Al, As, Cd, Sn, Pb, Ag, as impurity elements. Contains In, Au, P, S, Mg, Ti, Co, Mn, U, Th, etc.
- the content of Pb or Bi, or the combined content of both Pb and Bi is 1 ppm or more in total. It is preferable to do.
- even when the Ni ball 20 is exposed at the time of forming the solder joint it is not necessary to reduce the content of at least one of Pb and Bi of the Ni ball 20 to the minimum in order to reduce the ⁇ dose. This is due to the following reason.
- 210 Pb and 210 Bi change to 210 Po due to ⁇ decay.
- the contents of impurity elements Pb and Bi are as low as possible.
- the content ratio of 210 Pb and 210 Bi contained in Pb and Bi is low. If the contents of Pb and Bi are reduced to some extent, it is considered that 210 Pb and 210 Bi are almost removed.
- the Ni ball 20 according to the present invention is manufactured by setting the melting temperature of Ni slightly higher than before, or by subjecting the Ni material and / or the Ni ball 20 after ball formation to heat treatment. Even if this temperature is lower than the boiling point of Pb or Bi, vaporization occurs and the amount of impurity elements is reduced. Further, in order to increase the sphericity of the Ni ball 20, it is preferable that the content of the impurity element is high. Therefore, the Ni ball 20 of the present invention has a total content of at least one of Pb and Bi of 1 ppm or more. When both Pb and Bi are included, the total content of Pb and Bi is 1 ppm or more.
- the content measurement error is small.
- the content of at least one of Pb and Bi is preferably 1 ppm or more in total.
- the content of at least one of Pb and Bi is more preferably 10 ppm or more in total.
- the upper limit is not particularly limited, but from the viewpoint of suppressing the deterioration of the electrical conductivity of the Ni ball 20, more preferably the total content of at least one of Pb and Bi is less than 1000 ppm, and more preferably 100 ppm or less. .
- the content of Pb is more preferably 10 ppm to 50 ppm, and the content of Bi is more preferably 10 ppm to 50 ppm.
- the Ni ball 20 constituting the present invention has a sphericity of 0.90 or more from the viewpoint of maintaining an appropriate space between the substrates.
- the Ni ball 20 has an indefinite shape, so that bumps with non-uniform height are formed during bump formation, and the possibility of poor bonding is increased.
- the Ni ball 20 is displaced and the self-alignment property is also deteriorated.
- the sphericity is more preferably 0.94 or more. In the present invention, the sphericity represents a deviation from the sphere.
- the sphericity is obtained by various methods such as a least square center method (LSC method), a minimum region center method (MZC method), a maximum inscribed center method (MIC method), and a minimum circumscribed center method (MCC method).
- LSC method least square center method
- MZC method minimum region center method
- MIC method maximum inscribed center method
- MCC method minimum circumscribed center method
- the sphericity is an arithmetic average value calculated when the diameter of each of the 500 Ni balls is divided by the major axis, and the closer the value is to the upper limit of 1.00, the closer to the true sphere.
- the length of the major axis and the length of the diameter mean a length measured by an ultra quick vision, ULTRA QV350-PRO measuring device manufactured by Mitutoyo Corporation.
- Diameter of Ni ball 1 ⁇ 1000 ⁇ m
- the diameter of the Ni ball 20 constituting the present invention is preferably 1 to 1000 ⁇ m. Within this range, spherical Ni balls 20 can be stably manufactured, and connection short-circuiting when the terminals are at a narrow pitch can be suppressed.
- the diameter of the Ni balls 20 is preferably 1 to 300 ⁇ m.
- Ni powder is an aggregate of a large number of Ni balls 20 having the above-described characteristics. For example, it is distinguished from a single Ni ball 20 in the form of use, such as being blended as a powder in a solder paste. Similarly, when used for the formation of solder bumps, it is normally handled as an assembly, so that “Ni powder” used in such a form is distinguished from a single Ni ball 20.
- the Ni core ball can be constituted by the Ni ball 20 and a solder layer (metal layer) that covers the surface of the Ni ball 20.
- the composition of the solder layer is not particularly limited as long as it is an alloy composition of a solder alloy containing Sn as a main component.
- the solder layer may be a Sn plating film. Examples thereof include Sn, Sn—Ag alloy, Sn—Cu alloy, Sn—Ag—Cu alloy, Sn—In alloy, and those obtained by adding a predetermined alloy element thereto.
- the Sn content is 40% by mass or more.
- Sn—Bi alloy and Sn—Pb alloy can be used as the solder layer.
- alloy elements to be added include Ag, Cu, In, Ni, Co, Sb, Ge, P, and Fe.
- the alloy composition of the solder layer is preferably a Sn-3Ag-0.5Cu alloy from the viewpoint of drop impact characteristics.
- the thickness of the solder layer is not particularly limited, but is preferably 100 ⁇ m or less on one side. Generally, it may be 20 to 50 ⁇ m on one side.
- the contents of U and Th in the solder layer are each 5 ppb or less in order to make the ⁇ dose of the Ni core ball 0.0200 cph / cm 2 or less. Further, from the viewpoint of suppressing soft errors in current or future high-density mounting, the contents of U and Th are preferably 2 ppb or less, respectively.
- the Ni core ball can also be constituted by a Ni ball 20 and a plating layer (metal layer) made of one or more elements selected from Ni, Fe and Co covering the Ni ball 20.
- the thickness of the plating layer (metal layer) is generally 0.1 to 20 ⁇ m on one side.
- strike plating treatment may be performed in advance with a nickel hydrochloric acid solution or the like.
- the oxide film on the nickel surface can be removed, and the adhesion between the Ni balls and the solder plating can be improved during the manufacture of the Ni core balls.
- a flux layer can be coated on the surface of these Ni core balls.
- the surface of the Ni ball 20 according to the present invention can be covered with a flux layer.
- Form solder can be obtained by dispersing the Ni balls 20 according to the present invention in the solder. It can also be set as the solder paste containing the Ni ball
- the flux layer described above is composed of one or more components including a compound that acts as an activator for preventing the oxidation of the metal surface such as the Ni ball 20 and the solder layer and removing the metal oxide film during soldering.
- the flux layer may be composed of a plurality of components composed of a compound that acts as an activator and a compound that acts as an activity auxiliary agent.
- the flux layer may contain rosin or resin in order to protect a compound or the like acting as an activator from heat during reflow.
- the flux layer may include a resin that fixes a compound or the like acting as an activator to the Ni ball 20.
- any one of an amine, an organic acid, and a halogen, a combination of a plurality of amines, a combination of a plurality of organic acids, a combination of a plurality of halogens, and a simple substance can be used depending on the properties required in the present invention.
- a combination of one or more amines, organic acids, halogens is added.
- the activity auxiliary agent constituting the flux layer any of the above-described esters, amides and amino acids, combinations of a plurality of esters, combinations of a plurality of amides, combinations of a plurality of amino acids, single or A combination of esters, amides, amino acids is added.
- the active adjuvant that constitutes the flux layer is either an ester, an amide, or an amino acid, a combination of multiple esters, a combination of multiple amides, a combination of multiple amino acids, a single or multiple combinations A combination of esters, amides, amino acids is added.
- the flux layer may contain rosin or resin in order to protect the compound acting as an activator from heat during reflow. Further, the flux layer may include a resin that fixes a compound or the like acting as an activator to the solder layer.
- the flux layer may be composed of a single layer composed of a single compound or a plurality of compounds.
- the flux layer may be composed of a plurality of layers made of a plurality of compounds.
- the components constituting the flux layer adhere to the surface of the solder layer in a solid state. However, in the step of attaching the flux to the solder layer, the flux needs to be liquid or gaseous.
- the components constituting the flux layer need to be soluble in a solvent in order to coat with a solution.
- a salt when a salt is formed, there is a component that becomes insoluble in the solvent.
- the presence of components that are insoluble in the liquid flux makes it difficult to uniformly adsorb fluxes that contain poorly soluble components such as precipitates. For this reason, conventionally, a compound that forms a salt cannot be mixed to form a liquid flux.
- the flux layer can be formed one by one to be in a solid state, and a multilayer flux layer can be formed.
- the compound which forms a salt is used, Comprising: Even if it is a component which cannot be mixed with a liquid flux, a flux layer can be formed.
- the surface of the Ni core ball that is easily oxidized is coated with a flux layer that acts as an activator, so that oxidation of the surface of the solder layer of the Ni core ball can be suppressed during storage.
- Ni material is melted at a high temperature, and liquid molten Ni is sprayed from a nozzle at a high speed, whereby the mist-like molten Ni is rapidly cooled to room temperature (for example, 25 ° C.).
- room temperature for example, 25 ° C.
- Ni balls are formed.
- a gas is used as a medium when spraying molten Ni from a nozzle at a high speed, it is called a gas atomizing method, but the present invention is not limited to the gas atomizing method.
- Another atomizing method may be a method in which a molten Ni droplet is dropped from an orifice, and the droplet is rapidly cooled to form a Ni ball.
- Ni balls formed by each atomizing method may be reheated at a temperature of 800 to 1000 ° C. for 30 to 60 minutes. In the reheating process, the effect of the annealing process can be obtained by slowly cooling the Ni balls 20.
- the Ni material that is the raw material of the Ni ball 20 may be heat-treated at 800 to 1000 ° C. before the Ni ball 20 is formed.
- Ni material that is the raw material of the Ni balls 20 for example, pellets, wires, plate materials, and the like can be used.
- the purity of the Ni material may be 99.9 to 99.995% from the viewpoint of preventing the purity of the Ni ball 20 from being lowered too much.
- the above heat treatment may not be performed, and the molten Ni holding temperature may be lowered to about 1000 ° C. as in the conventional case.
- the above-described heat treatment may be omitted or changed as appropriate according to the purity of the Ni material and the ⁇ dose.
- Ni balls 20 having a high ⁇ dose or deformed Ni balls 20 are manufactured, these Ni balls 20 can be reused as raw materials, and the ⁇ dose can be further reduced. .
- the formed Ni ball 20 is annealed.
- the Ni balls 20 are heated for a predetermined time at 700 ° C. where annealing is possible, and then the heated Ni balls 20 are gradually cooled over a long time.
- the Ni ball 20 can be recrystallized and the slow crystal growth can be promoted, so that the Ni crystal grains can be greatly grown.
- the sphericity of Ni generally decreases.
- nickel oxide formed on the outermost surface of the Ni ball 20 functions as a high-purity impurity element, the outermost surface of the Ni ball 20 is in a state in which crystal grains are locally refined, and the Ni ball 20 is extremely hard. No reduction in sphericity occurs.
- Ni balls with high sphericity were produced, and the Vickers hardness and ⁇ dose of the produced Ni balls were measured.
- Ni wire having a purity of 99.9% ( ⁇ dose: 0.0034 cph / cm 2 , U: 0.7 ppb, Th: 0.5 ppb), Ni wire having a purity of 99.995 or less ( ⁇ dose: 0.0026 cph / cm cm 2 , U: ⁇ 0.5 ppb, Th: ⁇ 0.5 ppb).
- the discharge temperature is set to 1600 ° C., preferably 1700 ° C.
- liquid molten Ni is sprayed from the nozzle at a high speed by a gas atomizing method, and the atomized molten Ni is rapidly cooled to room temperature (18 ° C.) to form a Ni ball.
- Sphereed Ni balls having an average particle diameter of 250 ⁇ m were produced.
- Elemental analysis was performed by inductively coupled plasma mass spectrometry (ICP-MS analysis) for U and Th, and by inductively coupled plasma emission spectroscopic analysis (ICP-AES analysis) for the other elements. Below, the measuring method of sphericity, Vickers hardness, and alpha dose is explained in full detail.
- the sphericity was measured with a CNC image measurement system.
- the apparatus is an Ultra Quick Vision, ULTRA QV350-PRO manufactured by Mitutoyo Corporation.
- the Vickers hardness of the Ni balls was measured according to "Vickers hardness test-test method JIS Z2244".
- the equipment used was a micro Vickers hardness tester manufactured by Akashi Seisakusho and an AKASHI micro hardness tester MVK-F 12001-Q.
- ⁇ ⁇ dose The measurement method of ⁇ dose is as follows. For measuring the ⁇ dose, an ⁇ ray measuring device of a gas flow proportional counter was used. The measurement sample is obtained by spreading Ni balls in a 300 mm ⁇ 300 mm flat shallow container until the bottom of the container is not visible. This measurement sample was placed in an ⁇ -ray measuring apparatus and allowed to stand for 24 hours in a PR-10 gas flow, and then the ⁇ dose was measured.
- the PR-10 gas used for the measurement (90% argon—10% methane) was obtained after 3 weeks or more had passed since the gas cylinder was filled with the PR-10 gas.
- the cylinder that was used for more than 3 weeks was used because the JEDEC STANDARDE-Alpha Radiation Measuring Element was established by JEDEC (Joint Electron Engineering Engineering Coil) so that alpha rays would not be generated by radon in the atmosphere entering the gas cylinder. This is because JESD221 is followed.
- Table 1 shows the elemental analysis results, sphericity, Vickers hardness, and ⁇ dose of the produced Ni balls.
- the sphericity of the Ni ball using 99.9% purity Ni wire and 99.995% or less Ni wire was 0.90 or more. Was over 90HV. Further, as shown in Table 1, in the Ni ball using the Ni plate having a purity exceeding 99.995%, the Vickers hardness was 90 HV or less, but the sphericity was less than 0.90. Therefore, it can be seen that the Ni balls shown in Table 1 cannot satisfy both the sphericity required for the Ni balls according to the present invention of 0.90 or more and the Vickers hardness of 90 HV or less. It was.
- Example 1 Next, after putting Ni balls made of Ni wire having a purity of 99.9% into a carbon bat, the bat was carried into a continuous conveyor type electric resistance heating furnace and annealed. The annealing conditions at this time are shown in FIG. The inside of the furnace was in a nitrogen gas atmosphere in order to prevent oxidation of the Ni balls. The room temperature was 25 ° C.
- the annealing conditions are as follows: the temperature raising time for heating from room temperature to 700 ° C. is 60 minutes; the holding time for holding at 700 ° C. is 60 minutes; and the cooling time for cooling from 700 ° C. to room temperature is 120 minutes. Minutes.
- the inside of the furnace was cooled using a cooling fan installed in the furnace.
- acid treatment was performed by immersing Ni balls that had been annealed in 10% hydrochloric acid. This is to remove the oxide film formed on the surface of the Ni ball by the annealing process.
- Example 2 In Example 2, annealing treatment and oxide film removal treatment were performed on Ni balls made of Ni wires having a purity of 99.995% or less shown in Table 1 by the same method as in Example 1. . And the Vickers hardness of the obtained Ni ball
- Comparative example 1 In Comparative Example 1, the Vickers hardness of Ni balls made of Ni wire having a purity of 99.9% shown in Table 1 was measured. Further, each of the sphericity and ⁇ dose of the Ni ball was measured by the method described above. The measurement results are shown in Table 2 below.
- Comparative example 2 In Comparative Example 2, the Vickers hardness of Ni balls made of Ni wire having a purity of 99.995% or less shown in Table 1 was measured. Further, each of the sphericity and ⁇ dose of the Ni ball was measured by the method described above. The measurement results are shown in Table 2 below.
- Comparative example 3 In Comparative Example 3, the Vickers hardness of a Ni ball made of a Ni plate having the purity shown in Table 1 exceeding 99.995% was measured. Further, each of the sphericity and ⁇ dose of the Ni ball was measured by the method described above. The measurement results are shown in Table 2 below.
- the Vickers hardness of the Ni balls of Example 1 and Example 2 was 20 HV or more and 90 HV or less by performing the annealing treatment. Further, the sphericity of the Ni ball was ensured to be 0.90 or more even after the annealing treatment. A decrease in sphericity is predicted due to grain growth due to annealing, but according to the example, a higher sphericity was unexpectedly ensured.
- Ni balls having a purity of 99.9% or more and 99.995% or less are used, even when the Vickers hardness at the time of ball formation exceeds 90 HV, the annealing treatment is performed to perform the Vickers. It was proved that Ni balls having a hardness of 20 HV or more and 90 HV or less and a sphericity of 0.90 or more can be obtained.
- Example 1 and Example 2 as shown in Table 2, before and after the annealing treatment, the Ni ball ⁇ dose is 0.0010 cph / cm 2 or less, and a low ⁇ dose can be secured even after the annealing treatment. Was proved.
- the Ni balls of Comparative Example 1 and Comparative Example 2 have a sphericity of 0.90 or more, but have a Vickers hardness of over 90 HV. It was found that both the Vickers hardness and sphericity conditions of Ni balls were not met. Further, the Ni ball of Comparative Example 3 has a Vickers hardness of 90 HV or less, but the sphericity is less than 0.90, and the conditions for both the Vickers hardness and the sphericity of the Ni ball according to the present invention. It turns out that it does not satisfy.
- Example 3 Next, the sphericity and ⁇ dose before and after the annealing process of the Ni core ball using the Ni ball described above will be described.
- the sphericity and ⁇ dose of the Ni core ball produced by coating the surface of the Ni ball after the annealing treatment in Example 1 with a 1 ⁇ m Ni plating layer on one side were measured by the method described above. The measurement results are shown in Table 3 below.
- Example 4 the sphericity and ⁇ -dose of the Ni core ball produced by coating the surface of the Ni ball after the annealing treatment in Example 2 with a 1 ⁇ m Ni plating layer on one side were measured by the method described above. The measurement results are shown in Table 3 below.
- Example 5 the sphericity of the Ni core ball produced by coating the surface of the Ni ball after the annealing treatment in Example 1 with a solder plating layer made of Sn-3Ag-0.5Cu alloy of 20 ⁇ m on one side and The ⁇ dose was measured by the method described above. The measurement results are shown in Table 3 below.
- Example 6 the sphericity of the Ni core ball produced by coating the surface of the Ni ball after the annealing treatment in Example 2 with a solder plating layer made of Sn-3Ag-0.5Cu alloy of 20 ⁇ m on one side and The ⁇ dose was measured by the method described above. The measurement results are shown in Table 3 below.
- Example 7 the sphericity and ⁇ dose of Ni core balls produced by further coating the surface of Ni core balls coated with Ni plating in Example 3 with a solder plating layer were measured by the methods described above. did.
- Ni balls having a particle diameter of 250 ⁇ m are coated with a 1 ⁇ m Ni plating layer on one side and a 20 ⁇ m solder plating layer on one side, resulting in a Ni core ball having a particle diameter of 292 ⁇ m.
- the measurement results are shown in Table 3 below.
- Example 8 the sphericity and ⁇ dose of Ni core balls produced by further coating the surface of the Ni core balls coated with Ni plating in Example 4 with a solder plating layer were measured by the above-described methods. did.
- Ni balls having a particle diameter of 250 ⁇ m are coated with a 1 ⁇ m Ni plating layer on one side and a 20 ⁇ m solder plating layer on one side, resulting in a Ni core ball having a particle diameter of 292 ⁇ m.
- the measurement results are shown in Table 3 below.
- Comparative example 4 In Comparative Example 4, the sphericity and ⁇ dose of the Ni core ball produced by coating the surface of the Ni ball in Comparative Example 3 with a 1 ⁇ m Ni plating layer on one side were measured by the method described above. The measurement results are shown in Table 3 below.
- Comparative example 5 In Comparative Example 5, the sphericity and ⁇ dose of the Ni core ball produced by coating the surface of the Ni ball in Comparative Example 3 with a solder plating layer made of Sn-3Ag-0.5Cu alloy of 20 ⁇ m on one side are described above. It was measured by the method. The measurement results are shown in Table 3 below.
- Comparative Example 6 In Comparative Example 6, the sphericity and ⁇ dose of the Ni core ball produced by coating the surface of the Ni ball in Comparative Example 3 with the Ni plating layer and the solder plating layer in this order were measured by the method described above. In Comparative Example 6, Ni balls having a particle diameter of 250 ⁇ m are coated with a 1 ⁇ m Ni plating layer on one side and a 20 ⁇ m solder plating layer on one side, resulting in a Ni core ball having a particle diameter of 292 ⁇ m. The measurement results are shown in Table 3 below.
- the Ni core balls of Examples 3 to 8 had a sphericity of 0.90 or more in any of the examples, and the Ni balls were coated with a Ni plating layer or a solder plating layer. It was proved that high sphericity can be secured even when these layers are laminated.
- the Ni core balls of Examples 3 to 8 have an ⁇ dose of 0.0010 cph / cm 2 or less in any example, and the Ni balls are coated with a Ni plating layer or a solder plating layer. It was proved that a low ⁇ dose can be secured even when the layers are laminated.
- the ⁇ dose is 0.0010 cph / cm 2 or less, which satisfies the condition of the ⁇ dose of the Ni core ball according to the present invention.
- the sphericity was below 0.90, and it was found that the sphericity condition of the Ni core ball according to the present invention was not satisfied.
- ⁇ doses were measured when the flux layers were coated on the surfaces of the Ni balls of Example 1 and Example 2 and the Ni core balls of Examples 3 to 8, and the results are shown in Tables 2 and 3 above.
- the ⁇ dose is 0.0010 cph / cm 2 or less in any of the balls, which is the ⁇ dose of the Cu balls constituting the present invention, which is 0.0200 cph / cm, which is a preferable value for suppressing soft errors. Satisfies 2 or less.
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Abstract
Description
(1)純度が99.9%以上99.995%以下であり、真球度が0.90以上であり、ビッカース硬さが20HV以上90HV以下であるNiボール。
本発明に係るNiボールのビッカース硬さは、90HV以下であることが好ましい。ビッカース硬さが90HVを超える場合、外部からの応力に対する耐久性が低くなり、耐落下衝撃性が悪くなると共にクラックが発生し易くなるからである。また、三次元実装のバンプや継手の形成時に加圧等の補助力を付与した場合において、硬いNiボールを使用すると、電極潰れ等を引き起こす可能性があるからである。さらに、Niボール20のビッカース硬さが90HVを超える場合、結晶粒が一定以上に小さくなることで、電気伝導性の劣化を招いてしまうからである。本実施例では、生産性の高い急冷によりNiボールを製造した後、製造したNiボール20に対して結晶成長を促進させることによりビッカース硬さが90HV以下となるNiボール20を製造している。Niボール20の結晶成長を促進させる手段としては、例えば、アニーリング処理の他に、Niボール20の造球時に従来の急冷ではなく、徐冷工程を設けることも挙げられる。Niボール20を造球する製造装置として落下式の装置を使用する場合は、徐冷に非常に高い塔高さが必要となり実現は困難であるが、加熱炉式の造球方法であれば、冷却速度を遅くしたり搬送距離を長く設定したりする徐冷プロセスを設けることで対応することができる。
UおよびThは放射性元素であり、ソフトエラーを抑制するにはこれらの含有量を抑える必要がある。UおよびThの含有量は、Niボール20のα線量を0.0200cph/cm2以下とするため、各々5ppb以下にする必要がある。また、現在または将来の高密度実装でのソフトエラーを抑制する観点から、UおよびThの含有量は、好ましくは、各々2ppb以下である。
本発明を構成するNiボール20は純度が99.9%以上99.995%以下であることが好ましい。Niボール20の純度がこの範囲であると、Niボール20の真球度が高まるための十分な量の結晶核を溶融Cu中に確保することができる。真球度が高まる理由は以下のように詳述される。
本発明を構成するNiボール20のα線量は、0.0200cph/cm2以下であり、好ましくは0.0020cph/cm2以下であり、さらに好ましくは0.0010cph/cm2以下である。これは、電子部品の高密度実装においてソフトエラーが問題にならない程度のα線量である。従来、NiボールはNi材を1500℃以上に加熱して溶融させることで製造されることから、α線を放出する210Poなどの放射性元素の含有量が、揮発により十分に低減されて、Niのα線はソフトエラーの原因にならないと思われていた。しかし、従来行われてきたNiボールの製造条件により、Niボールのα線がソフトエラーを引き起こさない程度にまで低減することは立証されていない。210Poは沸点が962℃であり、1500℃以上の加熱でソフトエラーが発生しない程度にまで十分に揮発するとも思われる。しかし、Niボール製造時の加熱が210Poを揮発することを目的にしていたわけではないので、この温度で210Poが必ずしも十分に低減されるとは限らない。従来のNiボールの製造により低α線のNiボールが得られるかどうかは定かではない。
本発明を構成するNiボール20は、不純物元素としてSb、Cu、Bi、Zn、Fe、Al、As、Cd、Sn、Pb、Ag、In、Au、P、S、Mg、Ti、Co、Mn、U、Thなどを含有するが、特にPbまたはBiの含有量、もしくはPbおよびBiの両者を併せた含有量が合計で1ppm以上含有することが好ましい。本発明では、はんだ継手の形成時にNiボール20が露出した場合であっても、α線量を低減する上でNiボール20のPbおよびBiの少なくとも一方の含有量を極限まで低減する必要がない。これは以下の理由による。
本発明を構成するNiボール20は、基板間の適切な空間を保持する観点から真球度が0.90以上である。Niボール20の真球度が0.90未満であると、Niボール20が不定形状になるため、バンプ形成時に高さが不均一なバンプが形成され、接合不良が発生する可能性が高まる。さらに、Niボール20を電極に搭載してリフローを行う際、Niボール20が位置ずれを起こしてしまい、セルフアライメント性も悪化する。真球度は、より好ましくは0.94以上である。本発明において、真球度とは真球からのずれを表す。真球度は、例えば、最小二乗中心法(LSC法)、最小領域中心法(MZC法)、最大内接中心法(MIC法)、最小外接中心法(MCC法)など種々の方法で求められる。詳しくは、真球度とは、500個の各Niボールの直径を長径で割った際に算出される算術平均値であり、値が上限である1.00に近いほど真球に近いことを表す。本発明での長径の長さ、および直径の長さとは、ミツトヨ社製のウルトラクイックビジョン、ULTRA QV350-PRO測定装置によって測定された長さをいう。
本発明を構成するNiボール20の直径は1~1000μmであることが好ましい。この範囲にあると、球状のNiボール20を安定して製造でき、また、端子間が狭ピッチである場合の接続短絡を抑制することができる。Niボール20をはんだペーストに用いる場合、Niボール20の直径は1~300μmであることが好ましい。
真球度が高いNiボールの作製条件を検討した。純度が99.9%のNiワイヤー(α線量:0.0034cph/cm2、U:0.7ppb、Th:0.5ppb)、純度が99.995以下のNiワイヤー(α線量:0.0026cph/cm2、U:<0.5ppb、Th:<0.5ppb)を準備した。各々をるつぼの中に投入し、1000℃の温度条件で45分間予備加熱を行った。その後、吐出温度を1600℃、好ましくは1700℃として、ガスアトマイズ法により、液状の溶融Niをノズルから高速度で噴霧し、霧状の溶融Niを室温(18℃)まで急冷してNiボールを造球した。これにより、平均粒径が250μmのNiボールを作製した。元素分析は、UおよびThについては誘導結合プラズマ質量分析(ICP-MS分析)、その他の元素については誘導結合プラズマ発光分光分析(ICP-AES分析)により行った。以下に、真球度、ビッカース硬さ、そしてα線量の測定方法を詳述する。
真球度はCNC画像測定システムで測定した。装置は、ミツトヨ社製のウルトラクイックビジョン、ULTRA QV350-PROである。
Niボールのビッカース硬さは、「ビッカース硬さ試験-試験方法 JIS Z2244」に準じて測定した。装置は、明石製作所製のマイクロビッカース硬度試験器、AKASHI微小硬度計MVK-F 12001-Qを使用した。
α線量の測定方法は以下の通りである。α線量の測定にはガスフロー比例計数器のα線測定装置を用いた。測定サンプルは300mm×300mmの平面浅底容器にNiボールを容器の底が見えなくなるまで敷き詰めたものである。この測定サンプルをα線測定装置内に入れ、PR-10ガスフローにて24時間放置した後、α線量を測定した。
次に、純度99.9%のNiワイヤーで製造したNiボールをカーボン製バットに入れた後、このバットを連続コンベア式電気抵抗加熱炉に搬入してアニーリング処理を行った。このときの、アニーリング条件を図2に示す。なお、炉内は、Niボールの酸化を防止するために窒素ガス雰囲気にした。室温は25℃とした。
実施例2では、表1に示した純度が99.995%以下のNiワイヤーにより作製されたNiボールに対し、実施例1と同様の方法により、アニーリング処理を行うと共に酸化膜除去処理を行った。そして、得られたNiボールのビッカース硬さを測定した。また、アニーリング処理後におけるNiボールの真球度およびα線量のそれぞれを上述した方法により測定した。これらの測定結果を下記表2に示す。
比較例1では、表1に示した純度が99.9%のNiワイヤーにより作製されたNiボールのビッカース硬さを測定した。また、このNiボールの真球度およびα線量のそれぞれを上述した方法により測定した。これらの測定結果を下記表2に示す。
比較例2では、表1に示した純度が99.995%以下のNiワイヤーにより作製されたNiボールのビッカース硬さを測定した。また、このNiボールの真球度およびα線量のそれぞれを上述した方法により測定した。これらの測定結果を下記表2に示す。
比較例3では、表1に示した純度が99.995%を超えるNi板により作製されたNiボールのビッカース硬さを測定した。また、このNiボールの真球度およびα線量のそれぞれを上述した方法により測定した。これらの測定結果を下記表2に示す。
次に、上述したNiボールを用いたNi核ボールのアニーリング処理前後における真球度およびα線量について説明する。実施例3では、実施例1におけるアニーリング処理後のNiボールの表面に片側1μmのNiめっき層を被覆することにより作製されたNi核ボールの真球度およびα線量を上述した方法により測定した。これらの測定結果を下記表3に示す。
実施例4では、実施例2におけるアニーリング処理後のNiボールの表面に片側1μmのNiめっき層を被覆することにより作製されたNi核ボールの真球度およびα線量を上述した方法により測定した。これらの測定結果を下記表3に示す。
実施例5では、実施例1におけるアニーリング処理後のNiボールの表面に片側20μmのSn-3Ag-0.5Cu合金からなるはんだめっき層を被覆することにより作製されたNi核ボールの真球度およびα線量を上述した方法により測定した。これらの測定結果を下記表3に示す。
実施例6では、実施例2におけるアニーリング処理後のNiボールの表面に片側20μmのSn-3Ag-0.5Cu合金からなるはんだめっき層を被覆することにより作製されたNi核ボールの真球度およびα線量を上述した方法により測定した。これらの測定結果を下記表3に示す。
実施例7では、実施例3におけるNiめっきが被覆されたNi核ボールの表面にさらにはんだめっき層を被覆することにより作製された、Ni核ボールの真球度およびα線量を上述した方法により測定した。実施例7は、250μmの粒径のNiボールに、片側1μmのNiめっき層と片側20μmのはんだめっき層で被覆されており、292μmの粒径のNi核ボールとなる。これらの測定結果を下記表3に示す。
実施例8では、実施例4におけるNiめっきが被覆されたNi核ボールの表面にさらにはんだめっき層を被覆することにより作製された、Ni核ボールの真球度およびα線量を上述した方法により測定した。実施例8は、250μmの粒径のNiボールに、片側1μmのNiめっき層と片側20μmのはんだめっき層で被覆されており、292μmの粒径のNi核ボールとなる。これらの測定結果を下記表3に示す。
比較例4では、比較例3におけるNiボールの表面に片側1μmのNiめっき層を被覆することにより作製されたNi核ボールの真球度およびα線量を上述した方法により測定した。これらの測定結果を下記表3に示す。
比較例5では、比較例3におけるNiボールの表面に片側20μmのSn-3Ag-0.5Cu合金からなるはんだめっき層を被覆することにより作製されたNi核ボールの真球度およびα線量を上述した方法により測定した。これらの測定結果を下記表3に示す。
比較例6では、比較例3におけるNiボールの表面にNiめっき層およびはんだめっき層をこの順に被覆することにより作製された、Ni核ボールの真球度およびα線量を上述した方法により測定した。比較例6は、250μmの粒径のNiボールに、片側1μmのNiめっき層と片側20μmのはんだめっき層で被覆されており、292μmの粒径のNi核ボールとなる。これらの測定結果を下記表3に示す。
11,41 電極
12,42 はんだペースト
20 はんだボール
30 はんだバンプ
40 プリント基板
50 はんだ継手
60 電子部品
Claims (16)
- 純度が99.9%以上99.995%以下であり、真球度が0.90以上であり、ビッカース硬さが20HV以上90HV以下であるNiボール。
- Uの含有量が5ppb以下であり、Thの含有量が5ppb以下であり、PbおよびBiの少なくとも一方の含有量の合計量が1ppm以上であり、α線量が0.0200cph/cm2以下である請求項1に記載のNiボール。
- 直径が1~1000μmである請求項1または2に記載のNiボール。
- フラックス層が被覆されている請求項1~3のいずれか1項に記載のNiボール。
- 請求項1~3の何れか一項に記載のNiボールと、
前記Niボールを被覆するはんだ層とを備えるNi核ボール。 - 請求項1~3の何れか一項に記載のNiボールと、
前記Niボールを被覆するNi、FeおよびCoから選択される1元素以上からなるめっき層と備えるNi核ボール。 - 前記めっき層を被覆するはんだ層をさらに備える請求項6に記載のNi核ボール。
- 真球度が0.90以上である請求項5~7の何れか一項に記載のNi核ボール。
- 前記めっき層を被覆するはんだ層は、Uの含有量が5ppb以下であり、Thの含有量が5ppb以下であり、PbおよびBiの少なくとも一方の含有量の合計量が1ppm以上であり、α線量が0.0200cph/cm2以下である請求項5~7の何れか一項に記載のNi核ボール。
- フラックス層が被覆されている請求項5~9のいずれか1項に記載のNi核ボール。
- 請求項1~4のいずれか1項に記載のNiボールを使用したはんだ継手。
- 請求項1~4のいずれか1項に記載のNiボールを使用したはんだペースト。
- 請求項1~4のいずれか1項に記載のNiボールを使用したフォームはんだ。
- 請求項5~10のいずれか1項に記載のNi核ボールを使用したはんだ継手。
- 請求項5~10のいずれか1項に記載のNi核ボールを使用したはんだペースト。
- 請求項5~10のいずれか1項に記載のNi核ボールを使用したフォームはんだ。
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CN201480074896.6A CN105980086B (zh) | 2014-02-04 | 2014-02-04 | Ni球、Ni芯球、钎焊接头、焊膏和成形焊料 |
US15/116,280 US9802251B2 (en) | 2014-02-04 | 2014-02-04 | Ni ball, Ni core ball, solder joint, solder paste, and solder foam |
KR1020167023982A KR101691345B1 (ko) | 2014-02-04 | 2014-02-04 | Ni 볼, Ni 핵 볼, 납땜 조인트, 땜납 페이스트 및 폼 땜납 |
PCT/JP2014/052571 WO2015118613A1 (ja) | 2014-02-04 | 2014-02-04 | Niボール、Ni核ボール、はんだ継手、はんだペースト、およびフォームはんだ |
EP14881484.1A EP3103566B1 (en) | 2014-02-04 | 2014-02-04 | Ni ball, ni core ball, solder joint, solder paste, and solder foam |
JP2014524607A JP5585752B1 (ja) | 2014-02-04 | 2014-02-04 | Niボール、Ni核ボール、はんだ継手、はんだペースト、およびフォームはんだ |
TW104103151A TWI530350B (zh) | 2014-02-04 | 2015-01-30 | Nickel ball, nickel ball, soft welded joints, soft solder paste and foam solder |
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PCT/JP2014/052571 WO2015118613A1 (ja) | 2014-02-04 | 2014-02-04 | Niボール、Ni核ボール、はんだ継手、はんだペースト、およびフォームはんだ |
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Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1995024113A1 (fr) * | 1994-03-01 | 1995-09-08 | Sumitomo Special Metals Company Limited | Boule en cuivre et procede de production de cette derniere |
JP2002093866A (ja) * | 2000-09-12 | 2002-03-29 | Hoya Corp | ウエハ一括コンタクトボード用コンタクト部品及びその製造方法 |
JP2003249598A (ja) * | 2002-02-26 | 2003-09-05 | Kyocera Corp | 半導体素子収納用パッケージおよび半導体装置 |
JP2005338072A (ja) * | 2004-04-27 | 2005-12-08 | Jsr Corp | シート状プローブの製造方法 |
JP2007115857A (ja) * | 2005-10-20 | 2007-05-10 | Nippon Steel Chem Co Ltd | マイクロボール |
JP2010216004A (ja) * | 2009-02-20 | 2010-09-30 | Hitachi Metals Ltd | 電子部品用複合ボールの製造方法 |
WO2011114824A1 (ja) * | 2010-03-16 | 2011-09-22 | Jx日鉱日石金属株式会社 | α線量が少ない錫又は錫合金及びその製造方法 |
JP2011214061A (ja) * | 2010-03-31 | 2011-10-27 | Jx Nippon Mining & Metals Corp | α線量が少ないインジウム又はインジウムを含有する合金 |
WO2012120982A1 (ja) * | 2011-03-07 | 2012-09-13 | Jx日鉱日石金属株式会社 | α線量が少ない銅又は銅合金及び銅又は銅合金を原料とするボンディングワイヤ |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH01159339A (ja) * | 1987-12-15 | 1989-06-22 | Fujikura Ltd | ボンディングワイヤ |
JP2856197B2 (ja) * | 1997-06-06 | 1999-02-10 | 日本電気株式会社 | Bga接続構造 |
JP2004315871A (ja) * | 2003-04-15 | 2004-11-11 | Asahi Kasei Corp | 金属超微粒子の製造方法およびその製造装置 |
JP2005161338A (ja) * | 2003-12-01 | 2005-06-23 | Hitachi Metals Ltd | はんだシート |
EP1744166A1 (en) | 2004-04-27 | 2007-01-17 | JSR Corporation | Sheet-like probe, method of producing the probe, and application of the probe |
JP2007287712A (ja) | 2006-04-12 | 2007-11-01 | Oki Electric Ind Co Ltd | 半導体装置、半導体装置の実装構造、及びそれらの製造方法 |
CN101224499A (zh) * | 2008-02-19 | 2008-07-23 | 江苏工业学院 | 镍铝合金基金刚石超薄锯片及其制作方法 |
CN101462171B (zh) * | 2009-01-09 | 2011-02-16 | 南京大学 | 一种纳米镍球的制法 |
JP5510623B1 (ja) * | 2013-09-19 | 2014-06-04 | 千住金属工業株式会社 | Niボール、Ni核ボール、はんだ継手、フォームはんだ、はんだペースト |
-
2014
- 2014-02-04 CN CN201480074896.6A patent/CN105980086B/zh active Active
- 2014-02-04 JP JP2014524607A patent/JP5585752B1/ja active Active
- 2014-02-04 US US15/116,280 patent/US9802251B2/en active Active
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- 2014-02-04 WO PCT/JP2014/052571 patent/WO2015118613A1/ja active Application Filing
- 2014-02-04 KR KR1020167023982A patent/KR101691345B1/ko active IP Right Grant
-
2015
- 2015-01-30 TW TW104103151A patent/TWI530350B/zh active
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1995024113A1 (fr) * | 1994-03-01 | 1995-09-08 | Sumitomo Special Metals Company Limited | Boule en cuivre et procede de production de cette derniere |
JP2002093866A (ja) * | 2000-09-12 | 2002-03-29 | Hoya Corp | ウエハ一括コンタクトボード用コンタクト部品及びその製造方法 |
JP2003249598A (ja) * | 2002-02-26 | 2003-09-05 | Kyocera Corp | 半導体素子収納用パッケージおよび半導体装置 |
JP2005338072A (ja) * | 2004-04-27 | 2005-12-08 | Jsr Corp | シート状プローブの製造方法 |
JP2007115857A (ja) * | 2005-10-20 | 2007-05-10 | Nippon Steel Chem Co Ltd | マイクロボール |
JP2010216004A (ja) * | 2009-02-20 | 2010-09-30 | Hitachi Metals Ltd | 電子部品用複合ボールの製造方法 |
WO2011114824A1 (ja) * | 2010-03-16 | 2011-09-22 | Jx日鉱日石金属株式会社 | α線量が少ない錫又は錫合金及びその製造方法 |
JP2011214061A (ja) * | 2010-03-31 | 2011-10-27 | Jx Nippon Mining & Metals Corp | α線量が少ないインジウム又はインジウムを含有する合金 |
WO2012120982A1 (ja) * | 2011-03-07 | 2012-09-13 | Jx日鉱日石金属株式会社 | α線量が少ない銅又は銅合金及び銅又は銅合金を原料とするボンディングワイヤ |
Non-Patent Citations (1)
Title |
---|
See also references of EP3103566A4 * |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPWO2020066262A1 (ja) * | 2018-09-26 | 2021-09-24 | パナソニックIpマネジメント株式会社 | ニッケル粒子の製造方法、硫酸ニッケルの製造方法、及び二次電池用正極活物質の製造方法 |
JP7336749B2 (ja) | 2018-09-26 | 2023-09-01 | パナソニックIpマネジメント株式会社 | ニッケル粒子の製造方法、硫酸ニッケルの製造方法、及び二次電池用正極活物質の製造方法 |
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US20170080491A1 (en) | 2017-03-23 |
EP3103566A1 (en) | 2016-12-14 |
US9802251B2 (en) | 2017-10-31 |
EP3103566B1 (en) | 2018-11-14 |
EP3103566A4 (en) | 2017-11-01 |
TW201534420A (zh) | 2015-09-16 |
JP5585752B1 (ja) | 2014-09-10 |
KR101691345B1 (ko) | 2016-12-29 |
JPWO2015118613A1 (ja) | 2017-03-23 |
KR20160106773A (ko) | 2016-09-12 |
TWI530350B (zh) | 2016-04-21 |
CN105980086A (zh) | 2016-09-28 |
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