Abstract: A solder material having a good thermal-cycle fatigue property and wettability. The solder material contains not less than 5.0% by mass and not more than 8.0% by mass Sb, not less than 3.0% by mass and not more than 5.0% by mass Ag, and the balance of Sn and incidental impurities. Also, a semiconductor device may include a joining layer between a semiconductor element and a substrate electrode or a lead frame, the joining layer being obtained by melting this solder material.

Abstract: A solder alloy is used for soldering, and its chemical composition in mass % includes: 2.0 to 4.0% of Ag; 0.6 to 1.2% of Cu; 2.0 to 5.0% of Sb; 1.1 to 3.5% of In; 0 to 0.20% of Ni; 0 to 0.20% of Co; 0 to 0.05% of Ge; and balance of Sn, and impurities.

Abstract: A method for soldering a die obtained using the semiconductor technique with a leadframe, comprising the steps of providing a leadframe, which has at least one surface made at least partially of copper; providing a die, which has at least one surface coated with a metal layer; applying to the surface a solder alloy comprising at least 40 wt % of tin or at least 50% of indium or at least 50% of gallium, without lead, and heating the alloy to a temperature of at least 380° C. to form a drop of solder alloy; providing a die, which has at least one surface coated with a metal layer; and setting the metal layer in contact with the drop of solder alloy to form the soldered connection with the leadframe. Moreover, a device obtained with said method is provided.

Abstract: A SnAgCuSb-based Pb-free solder alloy is disclosed. The disclosed solder alloy is particularly suitable for, but not limited to, producing solder joints, in the form of solder preforms, solder balls, solder powder, or solder paste (a mixture of solder powder and flux), for harsh environment electronics. An additive selected from 0.1-2.5 wt. % of Bi and/or 0.1-4.5 wt. % of In may be included in the solder alloy.

Abstract: Provided are a Cu core ball and a cu core column, which achieve dropping strength and strength against heat cycle. The Cu core ball (1) contains a Cu ball (2) made of Cu or a Cu alloy and a solder layer (3) which is made of a solder alloy composed of Sn and Cu and covers the Cu ball (2). The solder layer (3) contains not less than 0.1% through not more than 3.0% of Cu and the remainder is composed of Sn and impurities.

Abstract: Solder material used in soldering of an Au electrode including Ni plating containing P includes Ag satisfying 0.3?[Ag]?4.0, Bi satisfying 0?[Bi]?1.0, and Cu satisfying 0?[Cu]?1.2, where contents (mass %) of Ag, Bi, Cu and In in the solder material are denoted by [Ag], [Bi], [Cu], and [In], respectively. The solder material includes In in a range of 6.0?[In]?6.8 when [Cu] falls within a range of 0<[Cu]<0.5, In in a range of 5.2+(6?(1.55×[Cu]+4.428))?[In]?6.8 when [Cu] falls within a range of 0.5?[Cu]?1.0, In in a range of 5.2?[In]?6.8 when [Cu] falls within a range of 1.0<[Cu]?1.2. A balance includes only not less than 87 mass % of Sn.

Abstract: High Impact Toughness Alloy The invention provides an alloy, preferably a lead-free solder alloy, comprising: from 35 to 59% wt Bi; from 0 to 0.0 wt % Ag; from 0 to 1.0% wt Au; from 0 to 1.0% wt Cr; from 0 to 2.0% wt In; from 0 to 1.0% wt P; from 0 to 1.0% wt Sb; from 0 to 1.0% wt Sc; from 0 to 1.0% wt Y; from 0 to 1.0% wt Zn; from 0 to 1.0% wt rare earth elements; one or more of: 10 from greater than 0 to 1.0% wt Al; from 0.01 to 1.0% wt Ce; from greater than 0 to 1.0% wt Co; from greater than 0 to 0.0% wt Cu; from 0.001 to 1.0% wt Ge; from greater than 0 to 0.0% wt Mg; from greater than 0 to 1.0% wt Mn; from 0.01 to 1.0% wt Ni; and from greater than 0 to 1.0% wt Ti, and the 1 balance Sn, together with any unavoidable impurities.

Abstract: A solder joint which is used in power devices and the like and which can withstand a high current density without developing electromigration is formed of a Sn—Ag—Bi—In based alloy. The solder joint is formed of a solder alloy consisting essentially of 2-4 mass % of Ag, 2-4 mass % of Bi, 2-5 mass % of In, and a remainder of Sn. The solder alloy may further contain at least one of Ni, Co, and Fe.

Abstract: A solder material includes 1.0-4.0% by weight of Ag, 4.0-6.0% by weight of In, 0.1-1.0% by weight of Bi, 1% by weight or less (excluding 0% by weight) of a sum of one or more elements selected from the group consisting of Cu, Ni, Co, Fe and Sb, and a remainder of Sn. When a copper-containing electrode part of an electronic component is connected to a copper-containing electrode land of a substrate by using this solder material, a part having an excellent stress relaxation property can be formed in the solder-connecting part and a Cu—Sn intermetallic compound can be rapidly grown from the electrode land and the electrode part to form a strong blocking structure.

Abstract: A mounting structure 1 in which an electronic component 5 is surface-mounted with solder 4 to a wiring substrate 2 is disclosed. The solder is Sn—Ag—Bi—In-based solder containing 0.1% by weight or more and 5% by weight or less of Bi, and more than 3% by weight and less than 9% by weight of In, with the balance being made up of Sn, Ag and unavoidable impurities. The wiring substrate has a coefficient of linear expansion of 13 ppm/K or less in all directions. Thus, it is possible to realize a mounting structure using lead-free solder and for which the occurrence of cracks in a solder joint portion due to a 1000-cycle thermal shock test from ?40 to 150° C. has been suppressed.

Abstract: An ingot includes at least two metals selected from copper, tin, zinc and bismuth, wherein: (a) the ingot is a mechanical ingot, the at least two metals are 40-95 wt. % copper, 3-80 wt. % tin, 1-40 wt. % bismuth and/or 1-80 wt. % zinc, and other metals are present in a collective amount of 0-2 wt. %; or (b) the ingot is a cast ingot, the at least two metals are 40-80 wt. % copper, 3-80 wt. % tin, 1-40 wt. % bismuth and/or 1-80 wt. % zinc, and other metals are present in a collective amount of 0-2 wt. %, provided that when copper is present in the cast ingot in an amount greater than 69 wt. %, zinc is present in an amount less than 30 wt. %. Methods for preparing and casting the ingot are also disclosed, as is a system for casting a copper-bismuth alloy.

Abstract: An inexpensive lead-free solder which prevents the occurrence of tin pest at extremely low temperatures and which has good wettability and impact resistance has a composition consisting essentially of, in mass %, Cu: 0.5-0.8%, Bi: at least 0.1% and less than 1%, Ni: 0.02-0.04%, and a remainder of Sn.

Abstract: The present invention provides a method of making a substantially phase pure compound including a cation and an anion. The compound is made by mixing in a ball-milling device a first amount of the anion with a first amount of the cation that is less than the stoichiometric amount of the cation, so that substantially all of the first amount of the cation is consumed. The compound is further made by mixing in a ball-milling device a second amount of the cation that is less than the stoichiometric amount of the cation with the mixture remaining in the device. The mixing is continued until substantially all of the second amount of the cation and any unreacted portion of anion X are consumed to afford the substantially phase pure compound.

Abstract: A lead-free solder alloy, a solder ball and an electronic member comprising a solder bump which enable the prevention of the occurrence of yellow discoloration on the surface of a solder after soldering, the surface of a solder bump after the formation of the bump in a BGA, and the surface of a solder bump after a burn-in test of a BGA. Specifically disclosed are: a lead-free solder alloy; a solder ball; and an electronic member comprising a solder bump, containing at least one additive element selected from Li, Na, K, Ca, Be, Mg, Sc, Y, lanthanoid series elements, Ti, Zr, Hf, Nb, Ta, Mo, Zn, Al, Ga, In, Si and Mn in the total amount of 1 ppm by mass to 0.1% by mass inclusive, with the remainder being 40% by mass or more of Sn.

Abstract: A new kind of Sn—In based Pb-free solders with Zn addition is disclosed, which includes: 15˜25 wt % In; 0.05˜1.5 wt % Zn; and balance Sn. When the solder of the present invention is used in the assembly of electrical products, the dissolution rates of the substrates and the growth of the intermetallic compounds formed at the interfaces can be reduced; and thereby the properties of joints can be improved.

Abstract: An Sn—Zn alloy solder having a composition comprising 7 to 10 mass % of Zn, 0.075 to 1 mass % of Ag, and 0.07 to 0.5 mass % of Al; further comprising one or two components selected from 0.01 to 6 mass % of Bi and 0.007 to 0.1 mass % of Cu; and optionally comprising 0.007 to 0.1 mass %, with the balance being Sn and unavoidable impurities. The solder has the same processability, service conditions, and connection reliability as conventional Sn-37 mass % Pb eutectic solder, and does not contain the biologically harmful lead.

Abstract: An active solder alloy, an electronic device package including the active solder alloy bonding an electronic device to a substrate, and a method of forming high-strength joints by soldering using the solder alloy. The alloy contains up to about 10% by weight of an element or a mixture of elements selected from the group consisting of titanium, zirconium, hafnium, vanadium, niobium, or tantalum; between about 0.1 and 5% by weight of an element or a mixture of elements selected from the group of the lanthanides (rare earths); between about 0.01 and 1% by weight of gallium up to about 10% by weight of silver; up to about 2% by weight of magnesium; and a remainder consisting of tin, bismuth, indium, cadmium, or a mixture of two or more of these elements. The alloy enables low-temperature (less than about 180° C.) soldering within relatively narrow melting ranges (less than about 10° C.).

Abstract: A Sn—Ag—Cu based lead-free solder ball which does not undergo yellowing of its surface when formed into a solder bump on an electrode of an electronic part such as a BGA package. The solder ball has excellent wettability and does not form voids at the time of soldering, even when it has a minute diameter such as 0.04-0.5 mm. It has a composition comprising 1.0-4.0 mass % of Ag, 0.05-2.0 mass % of Cu, 0.0005-0.005 mass % of P, and a remainder of Sn.

Abstract: A technique for technique for increasing the compliance of lead-free solders containing silver is disclosed. In one particular exemplary embodiment, the technique may be realized as a Sn—Ag—Al alloy composition comprising (0.01-20)% Ag, (0.01-2)% Al, balanced with Sn. In another particular exemplary embodiment, the technique may be realized as a Sn—Ag—Cu—Al alloy composition comprising (0.01-20)% Ag, (0.01-1)% Cu, (0.01-2)% Al, balanced with Sn. In still another particular exemplary embodiment, the technique may be realized as a Sn—Ag—Al—Ni composition comprising (0.01-20)% Ag, (0.01-2)% Al, (0.01-4)% Ni, balanced with Sn. In yet another particular exemplary embodiment, the technique may be realized as a Sn—Ag—Cu—Al—Ni alloy composition comprising (0.01-20)% Ag, (0.01-1)% Cu, (0.01-2)% Al, (0.01-4)% Ni, balanced with Sn.

Abstract: A technique for increasing the compliance of tin-indium solders is disclosed. In one particular exemplary embodiment, the technique may be realized as a lead free solder alloy comprising from about 58.0% to about 99.998% by weight tin, from about 0.001% to about 40.0% by weight indium, and from about 0.001% to about 2.0% by weight at least one rare earth element.

Abstract: The invention provides a solder alloy for bonding an oxide material, including more than 0% but not more than 1.0% of Mg and the balance being substantially Bi and Sn. Preferably, the alloy includes 0.01 to 0.6% of Mg, 35 to 86% of Bi, and the balance being substantially Sn. The invention can be used for bonding an oxide material, such as bonding glasses to each other. According to the invention, a low-cost solder joint of an oxide material is also provided.

Abstract: A lead free solder is provided. The lead free solder includes about 1.5 wt % to about 2.5 wt % silver (Ag), about 3 wt % to about 6 wt % bismuth (Bi), about 0.005 wt % to about 0.1 wt % of a deoxidizing agent, and a balance of tin (Sn). The lead free solder has improved wettability, a lowered melting point, little or substantially no formation of oxidation layer in a solder bath, suppressed brittleness, improved thermal shock resistance and drop resistance.

Abstract: To provide a solder alloy, a solder ball and an electronic member having a solder bump, used for connection with a mother board or the like, having a melting temperature of less than 250° C. for the solder alloy, achieving high drop impact resistance required in mobile devices or the like. A solder alloy is used which consists of not less than 0.1 mass ppm of boron and not greater than 200 mass ppm of boron and a remainder comprising substantially not less than 40% by mass of Sn, in which its melting temperature is less than 250° C.

Abstract: A recycling method of wastes of an electrical appliance containing an article having a circuit soldered with parts soldered with a lead free solder. The method includes discriminating a first article having a circuit soldered with lead free parts from a second article having a circuit soldered with lead containing parts; recovering, grinding and melting each of the first and second articles to separate materials of the first article and materials of the second article; recycling reusable valuables contained in the materials of the first article and second article; and shredding a portion of the first and second article not containing the reusable valuables and burying/treating the portion at a stabilizing dumping ground or a controlled dumping ground for disposal.

Abstract: The invention provides a solder alloy for bonding an oxide material, including more than 0% but not more than 1.0% of Mg and the balance being substantially Bi and Sn. Preferably, the alloy includes 0.01 to 0.6% of Mg, 35 to 86% of Bi, and the balance being substantially Sn. The invention can be used for bonding an oxide material, such as bonding glasses to each other. According to the invention, a low-cost solder joint of an oxide material is also provided.

Abstract: Provided is high purity tin or tin alloy wherein the respective contents of U and Th are 5 ppb or less, the respective contents of Pb and Bi are 1 ppm or less, and the purity is 5N or higher (provided that this excludes the gas components of O, C, N, H, S and P). This high purity tin or tin alloy is characterized in that the ? ray count of high purity tin having a cast structure is 0.001 cph/cm2 or less. Since recent semiconductor devices are densified and are of large capacity, there is considerable risk of a soft error occurring due to the influence of the ? ray from materials in the vicinity of the semiconductor chip. In particular, there are strong demands for purifying the soldering material or tin to be used in the vicinity of semiconductor devices, as well as for materials with fewer ? rays. Thus, the present invention aims to provide high purity tin or tin alloy and the manufacturing method of such high purity tin by reducing the ? dose of tin so as to be adaptable as the foregoing material.

Abstract: A lead-free solder includes at least one selected from 0.01 to 1% by weight of Co, 0.01 to 0.2% by weight of Fe, 0.01 to 0.2% by weight of Mn, 0.01 to 0.2% by weight of Cr, and 0.01 to 2% by weight of Pd; 0.5 to 2% by weight of Cu; and 90.5% by weight or more of Sn. This solder exhibits a satisfactory solderability in solder joints and shows a high resistance to electrode leaching upon soldering or when the resulting soldered article is left at high temperatures.

Abstract: A lead-free solder includes at least one selected from 0.01 to 1% by weight of Co, 0.01 to 0.2% by weight of Fe, 0.01 to 0.2% by weight of Mn, 0.01 to 0.2% by weight of Cr, and 0.01 to 2% by weight of Pd; 0.5 to 2% by weight of Cu; and 90.5% by weight or more of Sn. This solder exhibits a satisfactory solderability in solder joints and shows a high resistance to electrode leaching upon soldering or when the resulting soldered article is left at high temperatures.

Abstract: A solder composition having a mixture of elements including tin, indium, silver, and bismuth, and can include about 30% to 85% tin and about 15% to 65% indium.

Abstract: This invention relates to intermetallic negative electrode compounds for non-aqueous, electrochemical lithium cells and batteries. More specifically, the invention relates to one or more electrode components or compositions, one of which contains the basic structural unit of a MM?3 intermetallic compound, in which M and M? are comprised of one or more metals. The MM?3 intermetallic electrode compounds can be mixed, blended or integrated with one or more other intermetallic compounds, such as isostructural M3M? compounds. The electrodes are of particular use in rechargeable lithium-ion cells and batteries in numerous applications such as portable electronic devices, medical devices, space, aeronautical and defense-related devices and in transportation applications such as electric and hybrid-electric vehicles.

Abstract: A Pb-free Sn-based material part of a wiring conductor is provided at least at a part of a surface the wiring conductor, and the Sn-based material part includes a base metal doped with a transformation retardant element and an oxidation control element. The transformation retardant element is at least one element selected from a group consisted of Sb, Bi, Cd, In, Ag, Au, Ni, Ti, Zr, and Hf. The oxidation control element is at least one element selected from a group consisted of Ge, P, Zn, Kr, Cr, Mn, Na, V, Si, Al, Li, Mg and Ca. The wiring conductor is reflow processed, such that at least one of the Sn, the transformation retardant element and the oxidation control element is diffused to form an alloy.

Abstract: The present invention provides a Sn—Zn based lead-free solder which can prevent peeling of solder from soldered portions even after the passage of long periods after soldering of portions to be soldered made of Cu. A Sn—Zn based lead-free solder according to the present invention comprises 5-10 mass percent of Zn, a total of 0.005-1.0 mass percent of at least one substance selected from the group consisting of Au, Pt, Pd, Fe, and Sb, optionally a total of at most 15 mass percent of at least one substance selected from the group consisting of Bi and In, and a remainder of Sn. This Sn—Zn based lead-free solder can be made into a solder paste using a rosin flux containing a halide such as an amine hydrochloride as an activator.

Abstract: A lead-free solder includes 0.05-5 mass % of Ag, 0.01-0.5 mass % of Cu, at least one of P, Ge, Ga, Al, and Si in a total amount of 0.001-0.05 mass %, and a remainder of Sn. One or more of a transition element for improving resistance to heat cycles, a melting point lowering element such as Bi, In, or Zn, and an element for improving impact resistance such as Sb may be added.

Abstract: A package substrate includes die solder pads and pin solder fillets. The pin solder fillets might comprise between approximately 90 wt % to approximately 99 wt % tin and approximately 10 wt % to 1 wt % antimony. The die solder pads might comprise between approximately 4 wt % to approximately 8 wt % bismuth, approximately 2 wt % to approximately 4 wt % silver, approximately 0 wt % to approximately 0.7 wt % copper, and approximately 87 wt % to approximately 92 wt % tin. The die solder pads might comprise between approximately 7 wt % to approximately 20 wt % indium, between approximately 2 wt % to approximately 4.5 wt % silver, between approximately 0 wt % to approximately 0.7 wt % copper, between approximately 0 wt % to approximately 0.5 wt % antimony, and between approximately 74.3 wt % to approximately 90 wt % tin.

Abstract: An Sn—Zn lead-free solder alloy according to the present invention is constructed in a manner such that it is an Sn-based solder alloy indispensably containing 6 to 10 wt % zinc at least, and further containing 0.0015 to 0.1 wt % magnesium, said magnesium content being effective quantity for forming a protective magnesium oxide film on the solder surface and also for destroying said oxide film during soldering. When solder paste is preserved, the inside of solder particle is protected by the protective magnesium oxide film formed on the surface of solder particle, and a reaction between zinc and an activator is suppressed, so that preservation stability is improved, and at elevated temperature during soldering, a state where said protective oxide film is easily destroyed is obtained, so that good wettability is held.

Abstract: An Sn—Zn lead-free solder alloy according to the present invention is constructed in a manner such that it is an Sn-based solder alloy indispensably containing 6 to 10 wt % zinc at least, and further containing 0.0015 to 0.1 wt % magnesium, said magnesium content being effective quantity for forming a protective magnesium oxide film on the solder surface and also for destroying said oxide film during soldering. When solder paste is preserved, the inside of solder particle is protected by the protective magnesium oxide film formed on the surface of solder particle, and a reaction between zinc and an activator is suppressed, so that preservation stability is improved, and at elevated temperature during soldering, a state where said protective oxide film is easily destroyed is obtained, so that good wettability is held.

Abstract: A solder which can form a soldered joint of good bonding strength on a Ni layer containing a small amount of P formed from electroless Ni plating with a P-containing plating solution comprises 60–64 mass % of Sn, 0.002–0.01 mass % of P, 0.04–0.3 mass % of Cu, and a remainder of Pb. The solder is particularly suitable for forming a solder bump on a Cu electrode which has been coated with Ni by electroless plating.

Abstract: A doped tin-indium solder composition is disclosed. The doped tin-indium solder exhibits a retained fine-grain structure and superplasticity after significant thermal cycling and thermal and mechanical stresses experienced in a microelectronic package. A process of forming the doped tin-indium solder is also disclosed. A microelectronic package is also disclosed that uses the doped tin-indium solder composition. A method of assembling a microelectronic package is also disclosed. A computing system is also disclosed that includes the doped tin-indium solder.

Abstract: A first metal is plated onto a substrate comprising a second metal by immersing the substrate into a bath comprising a compound of the first metal and an organic diluent. The second metal is more electropositive than the first metal. The organic diluent has a boiling point higher than a eutectic point in a phase diagram of the first and second metals. The bath is operated above the eutectic point but below the melting point of the second metal. For example, bismuth is immersion plated onto lead-free tin-based solder balls, and subsequently redistributed by fluxless reflow. Plated structures are also provided.

Abstract: A lead-free solder alloy comprises 1.0–5.0 wt % Ag, 0.01–0.5 wt % Ni, one or both of (a) 0.001–0.05 wt % Co and (b) at least one of P, Ge, and Ga in a total amount of 0.001–0.05 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.

Abstract: A lead-free solder includes at least one selected from 0.01 to 1% by weight of Co, 0.01 to 0.2% by weight of Fe, 0.01 to 0.2% by weight of Mn, 0.01 to 0.2% by weight of Cr, and 0.01 to 2% by weight of Pd; 0.5 to 2% by weight of Cu; and 90.5% by weight or more of Sn. This solder exhibits a satisfactory solderability in solder joints and shows a high resistance to electrode leaching upon soldering or when the resulting soldered article is left at high temperatures.

Abstract: A lead-free solder powder that can include a plurality of lead-free solder particles each having a general spherical shape with a diameter of 20–60 ?m. Each of the lead-free solder particles can contain Sn, Ag and Bi, with respective concentrations set such that the lead-free solder alloy has a melting temperature lower than a predetermined heat-resistant temperature of a work to be soldered.

Abstract: The invention relates to an alloy type thermal fuse and a wire member for a thermal fuse element, and provides an alloy type thermal fuse in which a fuse element does not contain a harmful metal, the operating temperature is about 150° C., the dispersion of the operating temperature can be sufficiently suppressed, and the operation stability to a heat cycle can be satisfactorily assured. The thermal fuse has an alloy composition of 30 to 70% Sn, 0.3 to 20% Sb, and a balance Bi.

Abstract: Lead-free Tin-Zinc alloy contains Manganese in the amount of about 0.001-0.9 wt. %. The alloy is suitable for use as a solder with commercially available fluxes. Various types of solders can be prepared from the alloy, like wire, cored wire, atomized powder, solder paste, thin sheet, ribbon foil, perform etc. The alloy has improved mechanical and electrical properties in comparison with conventional Tin-Lead alloys Sn9Zn and 63Sn37Pb.

Abstract: A solder paste comprising a powder of a Zn-containing Sn-based, lead-free solder mixed with an activator-containing rosin-based flux to which 0.5-10.0 wt % of isocyanuric acid or a haloalkyl ester thereof is added can prevent the formation of solder balls and voids during reflow soldering and exhibit good solderability. A solder paste comprising a powder of an Ag- or Zn-containing Sn-based, lead-free solder mixed with an activator-containing rosin-based flux to which 0.01-10.0 wt % of a salicylamide compound also does not exhibit a change in viscosity and exhibits good solderability.

Abstract: Disclosed is a lead-free solder alloy containing 43 to 47% by weight of bismuth, 0.5 to 2.5% by weight of silver, 0.25 to 0.75% by weight of copper, 0.25 to 0.75% by weight of indium, 0.02 to 0.09% by weight of nickel and the balance of tin.

Abstract: A printed wiring board is provided in which lift-off and land peeling do not occur during soldering of an inserted component onto the printed wiring board, and hence pattern breakage does not occur, but with no increase in cost. A plurality of lands 6 are each formed continuously across surfaces of a substrate and an inner peripheral surface of one of a plurality of soldering through holes 5 into which leads 2 of an inserted component 3 to be mounted onto the printed wiring board are inserted before soldering is carried out, and a solder resist 8 is coated onto the lands 6.

Abstract: This invention discloses a lead-free Sn—Zn—Al—Ag solder alloy, which is composed of 7-10 wt % of Zn, up to 0.5 wt % of Al, up to 4.0 wt % of Ag, and the balance of Sn; and a lead-free Sn—Zn—Al—Ag—Ga solder alloy, which is composed of 7-10 wt % of Zn, up to 0.5 wt % of Al, up to 4.0 wt % of Ag, up to 4.0 wt % of Ga; and the balance of Sn. The lead-free solder alloys of the present invention have better tensile strength and elongation than the conventional Sn—Pb solder alloys. In addition, the lead-free solder alloys of the present invention have a melting point lower than 200° C., which is close to the 183.5° C. of an eutectic Sn—Pb alloy.

Abstract: A lead-free solder includes 0.05-5 mass % of Ag, 0.01-0.5 mass % of Cu, at least one of P, Ge, Ga, Al, and Si in a total amount of 0.001-0.05 mass %, and a remainder of Sn. One or more of a transition element for improving resistance to heat cycles, a melting point lowering element such as Bi, In, or Zn, and an element for improving impact resistance such as Sb may be added.

Abstract: An Sn—Zn lead-free solder alloy according to the present invention is constructed in a manner such that it is an Sn-based solder alloy indispensably containing 6 to 10 wt% zinc at least and further containing 0.0015 to 0.03 wt% magnesium and 0.0010 to 0.006 wt% aluminum. Upon preservation of solder paste not only under refrigeration but also at a room temperature or higher, the inside of solder particle is protected by the protective magnesium/aluminum oxide film formed on the solder particle surface, and a reaction between zinc and an activator is suppressed, so that preservation stability is improved, and at the elevated temperature during soldering, the solder alloy enters a state where said protective oxide film is easily destroyed, so that good wettability is held.