Solder Material, Solder Paste, Solder Preform, Solder Joint and Method of Managing the Solder Material

• US 20170312860A1
• Filed: 11/05/2014
• Published: 11/02/2017
• Est. Priority Date: 11/05/2014
• Status: Active Grant

• Current Assignee: Senju Metal Industry Company Limited
• Original Assignee: Senju Metal Industry Company Limited
• Inventors: Hattori, Takahiro, Kawasaki, Hiroyoshi, Okada, Hiroshi, Roppongi, Takahiro, Soma, Daisuke, Sato, Isamu
• Granted Patent: US 10,717,157 B2
• Time in Patent Office: Days
• CPC Class Codes: B22F 1/16 Metallic particles coated with a non-metal coated with lubricating or binding agents or with organic material B22F1/10
• CPC Class Codes: B22F 1/17 Metallic particles coated with metal
• CPC Class Codes: B22F 1/18 Non-metallic particles coated with metal
• CPC Class Codes: B22F 2301/10 Copper
• CPC Class Codes: B22F 2301/30 Low melting point metals, i.e. Zn, Pb, Sn, Cd, In, Ga
• CPC Class Codes: B22F 9/08 by casting, e.g. through sieves or in water, by atomising or spraying using electric discharge B22F9/14
• CPC Class Codes: B23K 35/0222 for use in soldering, brazing B23K35/0205 takes precedence
• CPC Class Codes: B23K 35/0233 Sheets, foils B23K35/0244 takes precedence
• CPC Class Codes: B23K 35/025 Pastes, creams, slurries
• CPC Class Codes: B23K 35/262 Sn as the principal constituent
• CPC Class Codes: B23K 35/302 Cu as the principal constituent
• CPC Class Codes: C22C 13/00 Alloys based on tin
• CPC Class Codes: C22F 1/08 of copper or alloys based thereon
• CPC Class Codes: C25D 17/16 Apparatus for electrolytic coating of small objects in bulk
• CPC Class Codes: C25D 3/60 containing more than 50% by weight of tin
• CPC Class Codes: C25D 5/12 at least one layer being of nickel or chromium
• CPC Class Codes: C25D 7/00 Electroplating characterised by the article coated
• CPC Class Codes: C25D 7/06 Wires; Strips; Foils

Abstract

Provided is a solder material having oxidation resistance at the time of melting solder or after melting it, as well as managing a thickness of oxide film at a fixed value or less before melting the solder. A Cu core ball 1A is provided with a Cu ball 2A for keeping a space between a semiconductor package and a printed circuit board and a solder layer 3A that covers the Cu ball 2A. The solder layer 3A is composed of Sn or a solder alloy whose main component is Sn. For the Cu core ball 1A, lightness is equal to or more than 65 in the L*a*b* color space and yellowness is equal to or less than 7.0 in the L*a*b* color space, and more preferably, the lightness is equal to or more than 70 and the yellowness thereof is equal to or less than 5.1.

Claims

1. A solder material containing a core for keeping a space between a joining object and an object to be joined, and a covering layer that covers the core, characterized in that the covering layer is composed of Sn or a solder alloy having a main component of Sn;

and

lightness of the solder material is equal to or more than 65 in the L*a*b* color space and yellowness thereof is equal to or less than 7.0 in the L*a*b* color space.

2. The solder material according to claim 1 characterized in that a thickness of an oxide film formed on a surface of the covering layer is equal to or less than 3.8 nm.

3. The solder material according to claim 1 or claim 2 characterized in that the lightness of the solder material is equal to or more than 70 and the yellowness thereof is equal to or less than 5.1.

6. The solder material according to any one of claims 1 through 5 characterized in that the core is covered with a layer which contains at least one element selected from a group of Ni and Co, and is covered with the solder layer.

7. The solder material according to any one of claims 1 through 6 characterized in that the core is composed of a single metal of Cu, Ni, Ag, Bi, Pb, Al, Sn, Fe, Zn, In, Ge, Sb, Co, Mn, Au, Si, Pt, Cr, La, Mo, Nb, Pd, Ti, Zr or Mg, an alloy thereof, a metal oxide thereof, a mixed metal oxide thereof, or a resin material in a spherical shape.

8. The solder material according to any one of claims 1 through 6 characterized in that the core is composed of a single metal of Cu, Ni, Ag, Bi, Pb, Al, Sn, Fe, Zn, In, Ge, Sb, Co, Mn, Au, Si, Pt, Cr, La, Mo, Nb, Pd, Ti, Zr or Mg, an alloy thereof, a metal oxide thereof, a mixed metal oxide thereof, or a resin material in a cylindrical shape.

9. Solder paste characterized in that the solder material according to any one of claims 1 through 8 is used.

10. Solder preform characterized in that the solder material according to any one of claims 1 through 8 is used.

11. A solder joint characterized in that the solder material according to any one of claims 1 through 8 is used.

12. A solder material characterized in that alpha dose of at least one selected from a group of the core, the covering layer, and a whole solder material in the solder material according to any one of claims 1 through 8 is equal to 0.0200 cph/cm² or less.

4. A solder material containing a core for keeping a space between a joining object and an object to be joined, and a covering layer that covers the core, characterized in that the covering layer comprises Sn of 40% or more and Ge of 20 ppm or more and 220 ppm or less.

5. The solder material according to claim 4 characterized in that lightness of the solder material is equal to or more than 65 in the L*a*b* color space and the yellowness thereof is equal to or less than 7.0 in the L*a*b* color space.

13. A method of managing a solder material which includes a core for keeping a space between a joining object and an object to be joined and a covering layer that covers the core, wherein the covering layer is composed of Sn or a solder alloy having a main component of Sn, characterized in that the method comprises:

measuring lightness and yellowness of the solder material in the L*a*b* color space; and

selecting only a solder material showing the lightness of 65 or more and the yellowness of 7.0 or less based on the measurement result of the lightness and the yellowness of the solder material.