Galvanite Lead-free galvanizing solder formulation designed specifically for high quality repairs to galvanized steel surfaces. Simple, effective and easy to use, in both manufacturing and field applications. Metallurgically bonds to the steel, for a seamless protective barrier.[2]
KappFree provides good joint strength, vibration resistance, and thermal cycle fatigue resistance in both piping and electrical products as opposed to tin-lead solders. Higher working temperature. Wets well to brass, copper, and stainless steel. Good electrical conductivity.[3]
Kapp Eco-Babbitt[4] Commonly used in capacitor manufacturing as protective coating to shield against electromotive force (EMF) and electromagnetic interference (EMI) with the specified performance of the capacitor, to prevent current and charge leakage out of and within the layers of the capacitor, and to prevent the development of electron flows within the coating material itself, that would diminish capacitor performance, coating, and capacitor life.[4]
Sn10, UNS L54520, ASTM10B. Balls for CBGA components, replaced by Sn95.5Ag3.9Cu0.6.[7] Low cost and good bonding properties. Rapidly dissolves gold and silver, not recommended for those.[8] Used for fabrication of car radiators and fuel tanks, for coating and bonding of metals for moderate service temperatures. Body solder.[9] Has low thermal EMF, can be used as an alternative to Cd70 where parasitic thermocouple voltage has to be avoided.[10]
Crude solder for construction plumbing works, flame-melted. Used for soldering car engine radiators. Used for machine, dip and hand soldering of plumbing fixtures and fittings. Superior body solder.[9]
Sn30, UNS L54280, crude solder for construction plumbing works, flame-melted, good for machine and torch soldering.[12] Used for soldering car engine radiators. Used for machine, dip and hand soldering of plumbing fixtures and fittings. Superior body solder.[9]
Pb68Sn32
253
Pb
No
"Plumber solder", for construction plumbing works[13]
Kapp GalvRepair Economical solder for repairing & joining most metals including Aluminum and cast Iron. Have been used for cast Iron and galvanized surface repair.[14]
Economical solder for repairing & joining most metals including Aluminum and cast Iron. Have been used for cast Iron and galvanized surface repair.[14]
Pb67Sn33
187
230
Pb
No
PM 33, crude solder for construction plumbing works, flame-melted, temperature depends on additives
Sn40, UNS L54915. For soldering of brass and car radiators.[12] For bulk soldering, and where wider melting point range is desired. For joining cables. For wiping and joining lead pipes. For repairs of radiators and electrical systems.[9]
Sn50, UNS L55030. "Ordinary solder", for soldering of brass, electricity meters, gas meters, formerly also tin cans. General purpose, for standard tinning and sheetmetal work. Becomes brittle below ?150°C.[15][13] Low cost and good bonding properties. Rapidly dissolves gold and silver, not recommended for those.[8] For wiping and assembling plumbing joints for non-potable water.[9]
Savbit, Savbit 1, Sav1. Minimizes dissolution of copper. Originally designed to reduce erosion of the soldering iron tips. About 100 times slower erosion of copper than ordinary tin/lead alloys. Suitable for soldering thin copper platings and very thin copper wires.[17]
Sn60, ASTM60A, ASTM60B. Common in electronics, most popular leaded alloy for dipping. Low cost and good bonding properties. Used in both SMT and through-hole electronics. Rapidly dissolves gold and silver, not recommended for those.[8] Slightly cheaper than Sn63Pb37, often used instead for cost reasons as the melting point difference is insignificant in practice. On slow cooling gives slightly duller joints than Sn63Pb37.[17]
Sn63, ASTM63A, ASTM63B. Common in electronics; exceptional tinning and wetting properties, also good for stainless steel. One of the most common solders. Low cost and good bonding properties. Used in both SMT and through-hole electronics. Rapidly dissolves gold and silver, not recommended for those.[8]Sn60Pb40 is slightly cheaper and is often used instead for cost reasons, as the melting point difference is insignificant in practice. On slow cooling gives slightly brighter joints than Sn60Pb40.[17]
Bi52. Good fatigue resistance combined with low melting point. Reasonable shear strength and fatigue properties. Combination with lead-tin solder may dramatically lower melting point and lead to joint failure.[22]
Sn62. Common in electronics. The strongest tin-lead solder. Appearance identical to Sn60Pb40 or Sn63Pb37. Crystals of Ag3Sn may be seen growing from the solder. Extended heat treatment leads to formation of crystals of binary alloys. Silver content decreases solubility of silver, making the alloy suitable for soldering silver-metallized surfaces, e.g. SMD capacitors and other silver-metallized ceramics.[15][17][22] Not recommended for gold.[8] General-purpose.
Sn10, Pb88. Silver content reduces solubility of silver coatings in the solder. Not recommended for gold.[8] Forms a eutectic phase, not recommended for operation above 120°C.
Pb94, HMP alloy, HMP. Service temperatures up to 255°C. Useful for step soldering. Also can be used for extremely low temperatures as it remains ductile down to −200°C, while solders with more than 20% tin become brittle below −70°C. Higher strength and better wetting than Pb95Sn5.[17]
Wettability and low-temperature malleability of indium, strength improved by addition of silver. Particularly good for cryogenic applications. Used for packaging of photonic devices.
In50. Only one phase. Resoldering with lead-tin solder forms indium-tin and indium-lead phases and leads to formation of cracks between the phases, joint weakening and failure.[22] On gold surfaces gold-indium intermetallics tend to be formed, and the joint then fails in the gold-depleted zone and the gold-rich intermetallic.[27] Less gold dissolution and more ductile than lead-tin alloys.[8] Good thermal fatigue properties.
Cerroseal 35. Fairly well wets glass, quartz and many ceramics. Malleable, can compensate some thermal expansion differences. Low vapor pressure. Used in low temperature physics as a glass-wetting solder.[29]
In25. Low gold-leaching. Good thermal fatigue properties. Used for die attachment of e.g. GaAs dies.[27] Used also for general circuit assembly and packaging closures. Less dissolution of gold and more ductile than tin-lead alloy.[8]
Ag2.5, UNS L50132. Used during World War II to conserve tin. Poor corrosion resistance; joints suffered corrosion in both atmospheric and underground conditions, all had to be replaced with Sn-Pb alloy joints.[35] Torch solder.
Ag1.5, ASTM1.5S. High melting point, used for commutators, armatures, and initial solder joints where remelting when working on nearby joints is undesirable.[12] Silver content reduces solubility of silver coatings in molten solder. Not recommended for gold.[8] Standard PbAgSn eutectic solder, wide use in semiconductor assembly. Reducing protective atmosphere (e.g. 12% hydrogen) often used. High creep resistance, for use at both elevated and cryogenic temperatures.
Pb54Sn45Ag1
177
210
Pb
exceptional strength, silver gives it a bright long-lasting finish; ideal for stainless steel[12]
SAC305. It is the JEITA recommended alloy for wave and reflow soldering, with alternatives SnCu for wave and SnAg and SnZnBi for reflow soldering. Usable also for selective soldering and dip soldering. At high temperatures tends to dissolve copper; copper buildup in the bath has detrimental effect (e.g. increased bridging). Copper content must be maintained between 0.4–0.85%, e.g. by refilling the bath with Sn97Ag3 alloy. Nitrogen atmosphere can be used to reduce losses by dross formation. Dull, surface shows formation of dendritic tin crystals. Weakens at thermal cycling, concern of whisker growth, large Ag3Sn intermetallic platelet precipitates causing mechanical weakening and poor shock/drop performance. Tendency to creep.[39]
Sn98.5Ag1.0Cu0.5
220
225
No
Near
SAC105 alloy contains the least amount of silver among lead-free solders. It is compatible with all flux types and is relatively inexpensive; it exhibits good fatigue resistance, wetting and solder joint reliability
Sn95.8Ag3.5Cu0.7
217
218
No
Near
SN96C-Ag3.5 A commonly used alloy. Used for wave soldering. Usable also for selective soldering and dip soldering. At high temperatures tends to dissolve copper; copper buildup in the bath has detrimental effect (e.g. increased bridging). Copper content must be maintained between 0.4–0.85%, e.g. by refilling the bath with Sn96.5Ag3.5 alloy (designated e.g. SN96Ce). Nitrogen atmosphere can be used to reduce losses by dross formation. Dull, surface shows formation of dendritic tin crystals.
SN96C. Preferred by the European IDEALS consortium for reflow soldering. Usable also for selective soldering and dip soldering. At high temperatures tends to dissolve copper; copper buildup in the bath has detrimental effect (e.g. increased bridging). Copper content must be maintained between 0.4–0.85%, e.g. by refilling the bath with Sn96.2Ag3.8 alloy (designated e.g. SN96Ce). Nitrogen atmosphere can be used to reduce losses by dross formation. Dull, surface shows formation of dendritic tin crystals.
Sn95.25Ag3.8Cu0.7Sb0.25
No
Preferred by the European IDEALS consortium for wave soldering.
Recommended by the US NEMI consortium for reflow soldering. Used as balls for BGA/CSP and CBGA components, a replacement for Sn10Pb90. Solder paste for rework of BGA boards.[7] Alloy of choice for general SMT assembly.
SAC405. Lead-Free, Cadmium Free formulation designed specifically to replace Lead solders in Copper and Stainless Steel plumbing, and in electrical and electronic applications.[3]
Sn96, Sn96.5, 96S. Fine lamellar structure of densely distributed Ag3Sn. Annealing at 125°C coarsens the structure and softens the solder.[7] Creeps via dislocation climb as a result of lattice diffusion.[43] Used as wire for hand soldering rework; compatible with SnCu0.7, SnAg3Cu0.5, SnAg3.9Cu0.6, and similar alloys. Used as solder spheres for BGA/CSP components. Used for step soldering and die attachment in high power devices. Established history in the industry.[7] Widely used. Strong lead-free joints. Silver content minimizes solubility of silver coatings. Not recommended for gold.[8] Marginal wetting. Good for step soldering. Used for soldering stainless steel as it wets stainless steel better than other soft solders. Silver content does not suppress dissolution of silver metallizations.[17] High tin content allows absorbing significant amount of gold without embrittlement.[44]
Sn96Ag4
221
229
No
No
ASTM96TS. "Silver-bearing solder". Food service equipment, refrigeration, heating, air conditioning, plumbing.[12] Widely used. Strong lead-free joints. Silver content minimizes solubility of silver coatings. Not recommended for gold.[8]
Widely used. Strong lead-free joints. Silver content minimizes solubility of silver coatings. Not recommended for gold. Produces strong and ductile joints on Copper and Stainless Steel. The resulting joints have high tolerance to vibration and stress, with tensile strengths to 30,000 psi on Stainless.[45]
Produces strong and ductile joints on Copper and Stainless Steel. The resulting joints have high tolerance to vibration and stress, with tensile strengths to 30,000 psi on Stainless.[45]
Produces strong and ductile joints on Copper and Stainless Steel. The resulting joints have high tolerance to vibration and stress, with tensile strengths to 31,000 psi on Stainless.[45] Audio industry standard for vehicle and home theater speaker installations. Its 7% Silver content requires a higher temperature range, but yields superior strength and vibration resistance.[46]
Sn95Ag4Cu1
No
Sn
232
No
Pure
Sn99. Good strength, non-dulling. Use in food processing equipment, wire tinning, and alloying.[12] Susceptible to tin pest.
Sn99Cu1. Also designated as Sn99Cu1. Cheap alternative for wave soldering, recommended by the US NEMI consortium. Coarse microstructure with ductile fractures. Sparsely distributed Cu6Sn5.[1][47] Forms large dendritic ß-tin crystals in a network of eutectic microstructure with finely dispersed Cu6Sn5. High melting point unfavorable for SMT use. Low strength, high ductility. Susceptible to tin pest.[43] Addition of small amount of nickel increases its fluidity; the highest increase occurs at 0.06% Ni. Such alloys are known as nickel modified or nickel stabilized.[48]
Sn100C, a lead-free silver-free nickel-stabilized alloy. Similar to Sn99Cu1. The nickel content lowers copper erosion and promotes shiny solder fillet. The presence of germanium promotes flow and reduces dross formation. Performance similar to SAC alloys at lower cost. Dross formation rate comparable to lead-tin alloys.
K100LD, a lead-free silver-free nickel-stabilized alloy, with low dissolving (LD) of copper. Proprietary of Kester. Similar to Sn99Cu1. The nickel content lowers copper erosion and promotes shiny solder fillet. Bismuth acts in synergy with nickel to further reduce copper dissolution and reduces surface tension. Performance similar to SAC alloys at lower cost. K100LDa has 0.2% copper, used to refill wave soldering pots to counteract copper buildup. Lower than optimal nickel content to avoid patents?[51]
SCA, SAC, or SnAgCu. Tin-silver-copper alloy. Relatively low-cost lead-free alloy for simple applications. Can be used for wave, selective and dip soldering. At high temperatures tends to dissolve copper; copper buildup in the bath has detrimental effect (e.g. increased bridging). Copper content must be maintained between 0.4–0.85%, e.g. by refilling the bath with Sn96.2Ag3.8 alloy (designated e.g. SN96Ce). Nitrogen atmosphere can be used to reduce losses by dross formation. Dull, surface shows formation of dendritic tin crystals.
For high-temperature uses. Allows removing insulation from an enameled wire and applying solder coating in a single operation. For radiator repairs, stained glass windows, and potable water plumbing.
High hardness, creep-resistant. For radiators, stained glass windows, and potable water plumbing. Excellent high-strength solder for radiator repairs. Wide range of patina and colors.
Zn100
419
No
Pure
For soldering aluminium. Good wettability of aluminium, relatively good corrosion resistance.[54]
Bi100
271
No
Pure
Used as a non-superconducting solder in low-temperature physics. Does not wet metals well, forms a mechanically weak joint.[29]
KappAloy9 Designed specifically for Aluminum-to-Aluminum and Aluminum-to-Copper soldering. It has good corrosion resistance and tensile strength. Lies between soft solder and silver brazing alloys, thereby avoiding damage to critical electronics and substrate deformation and segregation. Best solder for Aluminum wire to Copper busses or Copper wire to Aluminum busses or contacts.[55] UNS#: L91090
KappAloy15 Designed specifically for Aluminum-to-Aluminum and Aluminum-to-Copper soldering. It has good corrosion resistance and tensile strength. Lies between soft solder and silver brazing alloys, thereby avoiding damage to critical electronics and substrate deformation and segregation. Has a wide plastic range this makes it ideal for hand soldering Aluminum plates and parts, allowing manipulation of the parts as the solder cools.[55]
KappAloy30 For soldering of aluminium. Good wetting. Used extensively in spray wire form for capacitors and other electronic parts. Higher temperature and higher tensile strength compared to 85Sn/15Zn and 91Sn/9Zn.[55]
KappAloy20 For soldering of aluminium. Good wetting. Used extensively in spray wire form for capacitors and other electronic parts. Higher temperature and higher tensile strength compared to 85Sn/15Zn and 91Sn/9Zn.[55]
KappAloy40 For soldering of aluminium. Good wetting. Used extensively in spray wire form for capacitors and other electronic parts. Higher temperature and higher tensile strength compared to 85Sn/15Zn and 91Sn/9Zn.[55]
For low-temperature soldering of heat-sensitive parts, and for soldering in the vicinity of already soldered joints without their remelting.
Sn89Zn8Bi3
191
198
No
Prone to corrosion and oxidation due to its zinc content. On copper surfaces forms a brittle Cu-Zn intermetallic layer, reducing the fatigue resistance of the joint; nickel plating of copper inhibits this.[60]
Sb5, ASTM95TA. The US plumbing industry standard. It displays good resistance to thermal fatigue and good shear strength. Forms coarse dendrites of tin-rich solid solution with SbSn intermetallic dispersed between. Very high room-temperature ductility. Creeps via viscous glide of dislocations by pipe diffusion. More creep-resistant than SnAg3.5. Antimony can be toxic. Used for sealing chip packagings, attaching I/O pins to ceramic substrates, and die attachment; a possible lower-temperature replacement of AuSn.[43] High strength and bright finish. Use in air conditioning, refrigeration, some food containers, and high-temperature applications.[12] Good wettability, good long-term shear strength at 100°C. Suitable for potable water systems. Used for stained glass, plumbing, and radiator repairs.
Bi58. Reasonable shear strength and fatigue properties. Combination with lead-tin solder may dramatically lower melting point and lead to joint failure.[22] Low-temperature eutectic solder with high strength.[8] Particularly strong, very brittle.[5] Used extensively in through-hole technology assemblies in IBMmainframe computers where low soldering temperature was required. Can be used as a coating of copper particles to facilitate their bonding under pressure/heat and creating a conductive metallurgical joint.[60] Sensitive to shear rate. Good for electronics. Used in thermoelectric applications. Good thermal fatigue performance.[68] Established history of use. Expands slightly on casting, then undergoes very low further shrinkage or expansion, unlike many other low-temperature alloys which continue changing dimensions for some hours after solidification.[29]
In19. Low gold-leaching. Good thermal fatigue properties.
In52Sn48
118
No
Yes
In52. Suitable for the cases where low-temperature soldering is needed. Can be used for glass sealing.[60] Sharp melting point. Good wettability of glass, quartz, and many ceramics. Good low-temperature malleability, can compensate for different thermal expansion coefficients of joined materials.
Similar mechanical properties with Sn63Pb37, Sn62Pb36Ag2 and Sn60Pb40, suitable lead-free replacement. Contains eutectic Sn-In phase with melting point at 118°C, avoid use above 100°C.
Cerrolow 136. Slightly expands on cooling, later shows slight shrinkage in couple hours afterwards. Used as a solder in low-temperature physics.[29] Also the ChipQuik desoldering alloy.[81]
KappTec General purpose solder that will join all solderable metals except Aluminum. High temperature, high strength solder. It is used in applications where alloys melting higher than soft solders are required, but the cost and strength of Silver-brazing alloys is not necessary.[84]
Medium temperature alloy that provide strong, corrosion-resistant joints on most metals.[85] Also for soldering aluminium and die-castzinc alloys.[13] Used in cryogenic physics for attaching electrical potential leads to specimens of metals, as this alloy does not become superconductive at liquid helium temperatures.[29]
Medium temperature alloy that provide strong, corrosion-resistant joints on most metals. Works especially well on Aluminum-to-Aluminum and Aluminum-to-Copper joints, with excellent corrosion resistance and superior strength in high vibration and high stress applications in electronics, lighting and electrical products.[85]
Medium temperature alloy that provide strong, corrosion-resistant joints on most metals. Works especially well on Aluminum-to-Aluminum and Aluminum-to-Copper joints, with excellent corrosion resistance and superior strength in high vibration and high stress applications in electronics, lighting and electrical products.[85]
KappTecZ High temperature, high strength solder that may be used on most metals, but works extremely well on Aluminum, Copper and Stainless Steel. It has a high tolerance to vibration and stress, and good elongation for use on dissimilar metals. Above its liquidus of 600°F, this solder is extremely fluid and will penetrate the closest joints.[86]
KappRad[87] Developed specifically to join and repair Aluminum and Aluminum/Copper radiators and heat exchangers. A lower melting point makes delicate repair work easier.[87]
Au80. Good wetting, high strength, low creep, high corrosion resistance, high thermal conductivity, high surface tension, zero wetting angle. Suitable for step soldering. The original flux-less alloy, does not need flux. Used for die attachment and attachment of metal lids to semiconductor packages, e.g. kovar lids to ceramic chip carriers. Coefficient of expansion matching many common materials. Due to zero wetting angle requires pressure to form a void-free joint. Alloy of choice for joining gold-plated and gold-alloy plated surfaces. As some gold dissolves from the surfaces during soldering and moves the composition to non-eutectic state (1% increase of Au content can increase melting point by 30°C), subsequent desoldering requires higher temperature.[90] Forms a mixture of two brittle intermetallic phases, AuSn and Au5Sn.[91] Brittle. Proper wetting achieved usually by using nickel surfaces with gold layer on top on both sides of the joint. Comprehensively tested through military standard environmental conditioning. Good long-term electrical performance, history of reliability.[27] One of the best materials for soldering in optoelectronic devices and components packaging. Low vapor pressure, suitable for vacuum work. Generally used in applications that require a melting temperature over 150°C.[92] Good ductility. Also classified as a braze.
Au98. A non-eutectic alloy used for die attachment of silicon dies. Ultrasonic assistance is needed to scrub the chip surface so a eutectic (3.1% Si) is reached at reflow.
Au97.[90]AuSi3.2 is a eutectic with melting point of 363°C. AuSi forms a meniscus at the edge of the chip, unlike AuSn, as AuSi reacts with the chip surface. Forms a composite material structure of submicron silicon plates in soft gold matrix. Tough, slow crack propagation.[47]
In99. Used for die attachment of some chips. More suitable for soldering gold, dissolution rate of gold is 17 times slower than in tin-based solders and up to 20% of gold can be tolerated without significant embrittlement. Good performance at cryogenic temperatures.[94] Wets many surfaces incl. quartz, glass, and many ceramics. Deforms indefinitely under load. Does not become brittle even at low temperatures. Used as a solder in low-temperature physics, will bond to aluminium. Can be used for soldering to thin metal films or glass with an ultrasonic soldering iron.[29]
C-Solder. Lead-free, low-temperature soldering alloy for joining of various carbon materials including carbon fibres and carbon nanotube fibres in both carbon-carbon and carbon-metal arrangements. Produces mechanically strong and electrically conductive bonds. Provides wetting of carbon[96] and other materials generally considered as difficult to solder, including aluminium, stainless steel, titanium, glass, and ceramics.
Notes on the above table
In the Sn-Pb alloys, tensile strength increases with increasing tin content. Indium-tin alloys with high indium content have very low tensile strength.[5]
Indium is a chemical element with the symbol In and atomic number 49. Indium is the softest metal that is not an alkali metal. It is a silvery-white metal that resembles tin in appearance. It is a post-transition metal that makes up 0.21 parts per million of the Earth's crust. Indium has a melting point higher than sodium and gallium, but lower than lithium and tin. Chemically, indium is similar to gallium and thallium, and it is largely intermediate between the two in terms of its properties. Indium was discovered in 1863 by Ferdinand Reich and Hieronymous Theodor Richter by spectroscopic methods. They named it for the indigo blue line in its spectrum. Indium was isolated the next year.
Solder is a fusible metal alloy used to create a permanent bond between metal workpieces. Solder is melted in order to wet the parts of the joint, where it adheres to and connects the pieces after cooling. Metals or alloys suitable for use as solder should have a lower melting point than the pieces to be joined. The solder should also be resistant to oxidative and corrosive effects that would degrade the joint over time. Solder used in making electrical connections also needs to have favorable electrical characteristics.
Tin is a chemical element with the symbol Sn and atomic number 50. A silvery-coloured metal, tin is soft enough to be cut with little force, and a bar of tin can be bent by hand with little effort. When bent, the so-called "tin cry" can be heard as a result of twinning in tin crystals; this trait is shared by indium, cadmium, zinc, and mercury in its solid state.
Pewter is a malleable metal alloy consisting of tin (85–99%), antimony, copper (2%), bismuth, and sometimes silver. Copper and antimony act as hardeners, but lead may be used in lower grades of pewter, imparting a bluish tint. Pewter has a low melting point, around 170–230 °C (338–446 °F), depending on the exact mixture of metals. The word pewter is probably a variation of the word spelter, a term for zinc alloys.
In metallurgy, a flux is a chemical cleaning agent, flowing agent, or purifying agent. Fluxes may have more than one function at a time. They are used in both extractive metallurgy and metal joining.
The Restriction of Hazardous Substances Directive 2002/95/EC, short for Directive on the restriction of the use of certain hazardous substances in electrical and electronic equipment, was adopted in February 2003 by the European Union.
Wave soldering is a bulk soldering process used for the manufacturing of printed circuit boards. The circuit board is passed over a pan of molten solder in which a pump produces an upwelling of solder that looks like a standing wave. As the circuit board makes contact with this wave, the components become soldered to the board. Wave soldering is used for both through-hole printed circuit assemblies, and surface mount. In the latter case, the components are glued onto the surface of a printed circuit board (PCB) by placement equipment, before being run through the molten solder wave. Wave soldering is mainly used in soldering of through hole components.
Babbitt metal or bearing metal is any of several alloys used for the bearing surface in a plain bearing.
An intermetallic is a type of metallic alloy that forms an ordered solid-state compound between two or more metallic elements. Intermetallics are generally hard and brittle, with good high-temperature mechanical properties. They can be classified as stoichiometric or nonstoichiometic intermetallic compounds.
The solderability of a substrate is a measure of the ease with which a soldered joint can be made to that material. Good solderability requires wetting of the substrate by the solder.
A fusible alloy is a metal alloy capable of being easily fused, i.e. easily meltable, at relatively low temperatures. Fusible alloys are commonly, but not necessarily, eutectic alloys.
Field's metal, also known as Field's alloy, is a fusible alloy that becomes liquid at approximately 62 °C (144 °F). It is named after its inventor, Simon Quellen Field. It is a eutectic alloy of bismuth, indium, and tin, with the following mass fractions: 32.5% Bi, 51% In, 16.5% Sn.
Dip soldering is a small-scale soldering process by which electronic components are soldered to a printed circuit board (PCB) to form an electronic assembly. The solder wets to the exposed metallic areas of the board, creating a reliable mechanical and electrical connection.
Bismuth is a chemical element with the symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens, with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental bismuth occurs naturally, and its sulfide and oxide forms are important commercial ores. The free element is 86% as dense as lead. It is a brittle metal with a silvery-white color when freshly produced. Surface oxidation generally gives samples of the metal a somewhat rosy cast. Further oxidation under heat can give bismuth a vividly iridescent appearance due to thin-film interference. Bismuth is both the most diamagnetic element and one of the least thermally conductive metals known.
Soldering is a process of joining two metal surfaces together using a filler metal called solder. The soldering process involves heating the surfaces to be joined and melting the solder, which is then allowed to cool and solidify, creating a strong and durable joint.
Tin-silver-copper, is a lead-free (Pb-free) alloy commonly used for electronic solder. It is the main choice for lead-free surface-mount technology (SMT) assembly in the industry, as it is near eutectic, with adequate thermal fatigue properties, strength, and wettability. Lead-free solder is gaining much attention as the environmental effects of lead in industrial products is recognized, and as a result of Europe's RoHS legislation to remove lead and other hazardous materials from electronics. Japanese electronics companies have also looked at Pb-free solder for its industrial advantages.
Cryogenic seals provide a mechanical containment mechanism for materials held at cryogenic temperatures, such as cryogenic fluids. Various techniques, including soldering and welding are available for creating seals; however, specialized materials and processes are necessary to hermetically entrap cryogenic constituents under vacuum-tight conditions. Most commonly used are liquid helium and liquid nitrogen, which boil at very low temperatures, below −153 °C, as well as hydrocarbons with low freezing points and refrigerating mixtures. Pure indium wire or solder preform washers are accepted as the most reliable low temperature sealing materials. When correctly formed, indium will afford leak rates of less than 4.0x10 -9 mbar- liter/sec. Alternative cryogenic seal materials include silicone grease conical seals, and Pb/Sn (lead-tin) wire seals.
The metallic elements in the periodic table located between the transition metals to their left and the chemically weak nonmetallic metalloids to their right have received many names in the literature, such as post-transition metals, poor metals, other metals, p-block metals and chemically weak metals. The most common name, post-transition metals, is generally used in this article.
The elements bismuth and indium have relatively low melting points when compared to other metals, and their alloy bismuth–indium (Bi–In) is classified as a fusible alloy. It has a melting point lower than the eutectic point of the tin–lead alloy. The most common application of the Bi-In alloy is as a low temperature solder, which can also contain, besides bismuth and indium, lead, cadmium, and tin.
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