Senju Metal Industry Co., Ltd.

Matushita Electric Industrial Co., Ltd.

Panasonic Corporation

Osamu Munekata

Yoshitaka Toyoda

Minoru Ueshima

Tsukasa Ohnishi

Hiroyoshi Kawasaki

Hiroshi Okada

Kaichi Tsuruta

Rikiya Katoh

Hiroshi Takahashi

Masazumi Amagai

Takahiro Roppongi

Daisuke Soma

Toshihiko Taguchi

Satoshi Yokota

Masato Shiratori

Hiroshi Kawanago

Takashi Akagawa

Hiroki Sudo

Masako Watanabe

Kensho Murata

Masato Tsuchiya

Naoto Kameda

Katsuji Nakamura

Haruo Suzuki

Hirofumi Nogami

Norihisa Eguchi

Masayuki Ojima

Yuri Nakamura

In a layered bonding material, a coefficient of linear expansion of a base materialis 5.5 to 15.5 ppm/K and a first surface and a second surface of the base materialare coated with pieces of lead-free solderand

Layered bonding material, semiconductor package, and power module

A solder alloy is provided which suppresses the change in a solder paste over time, decreases the temperature difference between the liquidus-line temperature and the solidus temperature, and exhibits a high reliability. The solder alloy has an alloy constitution composed of: 10 ppm by mass or more and less than 25 ppm by mass of As; at least one selected from the group consisting of 0 ppm by mass to 10000 ppm by mass of Bi and 0 ppm by mass to 5100 ppm by mass of Pb; more than 0 ppm by mass and no more than 3000 ppm by mass of Sb; and a remaining amount of Sn; and satisfies both the formula (1) and the formula (2).300&#x2264;3As+Sb+Bi+Pb&#x2003;&#x2003;(1)0.1&#x2264;{(3As+Sb)/(Bi+Pb)}&#xd7;100&#x2264;200&#x2003;&#x2003;(2) In the formula (1) and the formula (2), As, Sb, Bi, and Pb each represents an amount thereof (ppm by mass) in the alloy constitution.

Solder alloy, solder power, and solder joint

The present invention provides a solder material containing Sn or a Sn-containing alloy and 40 to 320 ppm by mass of A, the solder material including an As-enriched layer.

Solder material, solder paste, and solder joint

A solder ball includes 0.1% by mass or more and 10% by mass or less of In and a remainder of Sn. The ball has a yellowness (b*) in an L*a*b* color system of 2.8 or more and 15.0 or less and a lightness (L*) of 60 or more and 100 or less. The ball further includes at least one element selected from a group of 0% by mass or more and 4% by mass or less of Ag, 0% by mass or more and 1.0% by mass or less of Cu, 0% to 3% by mass in total of Bi and/or Sb, and 0% to 0.1% by mass in total of an element selected from a group of Ni, Co, Fe, Ge, and P, excluding a solder ball including 3% by mass of Ag, 0.5% by mass of Cu, 0.2% by mass of In and a remainder of Sn.

Solder ball, solder joint, and joining method

A lead-free solder alloy suitable for use in flow soldering of electronic components to printed wiring boards comprises 0.1-3 wt % of Cu, 0.001-0.1 wt % of P, optionally 0.001-0.1 wt % of Ge, and a balance of Sn. The solder alloy may further contain at least one of Ag and Sb in a total amount of at most 4 wt %, and/or at least one of Ni, Co, Fe, Mn, Cr, and Mo in a total amount of at most 0.5 wt % in order to strengthen the alloy, and/or at least one of Bi, In, and Zn in a total amount of at most 5 wt % in order to lower the melting point of the alloy.

Lead-free solder alloy

A lead-free solder alloy suitable for use in flow soldering of electronic components to printed wiring boards comprises 0.1-3 wt % of Cu, 0.001-0.1 wt % of P, optionally 0.001-0.1 wt % of Ge, and a balance of Sn. The solder alloy may further contain at least one element of Ag and Sb in a total amount of at most 4 wt %, and/or at least one element of Ni, Co, Fe, Mn, Cr, and Mo in a total amount of at most 0.5 wt % in order to strengthen the alloy, and/or at least one element of Bi, In, and Zn in a total amount of at most 5 wt % in order to lower the melting point of the alloy.

The rate of decrease of an oxidation suppressing element in a solder bath is measured during a soldering operation. Soldering is then carried out while replenishing the solder bath is then replenished during soldering so as to maintain the surface level of molten solder in the bath with a replenishment solder alloy which supplies the oxidation suppressing element to the solder bath at at least the rate at which the oxidation suppressing element is consumed during soldering. When the oxidation suppressing element is P, the concentration of P in the replenishment solder alloy is preferably 60-100 ppm.

Method of replenishing an oxidation suppressing element in a solder bath

A lead-free solder alloy comprises 1.0&#x2013;5.0 wt % Ag, 0.01&#x2013;0.5 wt % Ni, one or both of (a) 0.001&#x2013;0.05 wt % Co and (b) at least one of P, Ge, and Ga in a total amount of 0.001&#x2013;0.05 wt %, and a remainder of Sn. The solder can form solder bumps which have a high bonding strength and which do not undergo yellowing after soldering.

A lead-free solder paste suitable for soldering chip parts includes a powder of a twin-peak Sn-based solder alloy containing 0.2-1.0 mass % of Ag and a flux. The solder alloy has a first peak of heat absorption in a differential scanning calorimeter curve at the start of melting and a second peak when the major portion of the alloy subsequently melts.

Lead-free solder paste

A solder paste suitable for use in reflow soldering of chip components having good soldering properties without causing tombstoning comprises a solder powder admixed with a viscous flux. The solder powder is comprised of a twin peak solder alloy consisting essentially, on a weight basis, of: 60-65% Sn, 0.1-0.6% Ag, 0.1-2% Sb, and a balance of Pb, and having a liquidus temperature below 200.degree. C.

Growing community of inventors

Souka, Japan

Osamu Munekata