CN104112608A - Switch contact with refractory metal alloy coating layer and preparation method thereof - Google Patents
Switch contact with refractory metal alloy coating layer and preparation method thereof Download PDFInfo
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- CN104112608A CN104112608A CN201410346547.7A CN201410346547A CN104112608A CN 104112608 A CN104112608 A CN 104112608A CN 201410346547 A CN201410346547 A CN 201410346547A CN 104112608 A CN104112608 A CN 104112608A
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
- C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
- C23C18/48—Coating with alloys
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H1/02—Contacts characterised by the material thereof
- H01H1/021—Composite material
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H11/00—Apparatus or processes specially adapted for the manufacture of electric switches
- H01H11/04—Apparatus or processes specially adapted for the manufacture of electric switches of switch contacts
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Abstract
The invention discloses a switch contact with a refractory metal alloy coating layer and a preparation method thereof. A contact part is in a three-layer structure, the first layer is a hydrophobic rubber layer, the second layer is a sheet metal layer, and the third layer is a chemically deposited layer of a refractory metal alloy. A plating solution used for chemical deposition contains a soluble tungsten compound, a soluble molybdenum compound and the like. When a layered complex of the hydrophobic rubber layer and the sheet metal layer performs chemical deposition by the aid of the plating solution, the refractory metal alloy coating layer is selectively deposited on metal surfaces. The prepared switch contact has the advantages that the metal luster and color is good, the contact resistance and the costs are low, the resistance to switching arc erosion is high, the service life is long, and the switch contact is suitable for heat vulcanization bonding and forming with rubber.
Description
Technical field
Can be by being in contact with one another parts (namely electrical contact or contact) that the stream of can powering passes through and preparation method thereof thereby the present invention is specifically related in switch in a kind of electric power or electronic product or circuit between two conductors.
Background technology
Thereby electrical contact or contact are the important spare parts passing through by being in contact with one another the stream of can powering between two conductors in switch or circuit, bear the function of connection, carrying and disjunction normal current and fault current, are directly determining quality and the useful life of whole switch or circuit in its quality and useful life.Electrical contact or contact are mainly used in relay, contactor, air switch, current limiting switch, motor protecter, microswitch, instrument and meter, computor-keyboard, hand-held set, household electrical appliance, car electrics (on-load switch such as car window switch, switch for rear-vision mirror, lamp switch, actuating motor), earth leakage circuit-breaker etc.Electric contact or contact to prepare material a lot, mainly contain silver, silver-colored nickel, silver copper oxide, Agcdo, siller tin oxide, silver-tin oxide or indium oxide, Ag-ZnO, red copper, brass, phosphor-copper, bronze, tin copper, beryllium copper, copper nickel, packfong, stainless steel etc.
In the equipment such as car electrics, household electrical appliance, computor-keyboard and hand-held set, its switch block is usually the printed circuit board (PCB) (PCB) that is provided with contact and the combination that is provided with the rubber key of contact.Circular contact on PCB, is divided into the two halves of not conducting by straight line or curve (as S type curve).Contact on button is the circle that need not cut apart.With the circular contact of a same diameter on button, do aspectant contact with a circular contact on PCB, just can connect a circuit on PCB.Slider material on button is conductive rubber or metal.Contact resistance when conductive rubber contact contacts with PCB contact is larger, and conductive rubber contact is not suitable for the PCB circuit of large (for example electric current is greater than 50 milliamperes) of making current.Contact resistance when hard contact contacts with PCB contact is less, and hard contact both can be for the less PCB circuit of making current, also can be for the larger PCB circuit of making current.Thereby make the problems such as its application is restricted but metal current contact exists that chemicals-resistant burn into arc ablation resistance performance is undesirable, cost of manufacture is high.
In atmosphere, switch element produces electric spark or electric arc often at connection circuit or minute deenergizing.The existence of switching arc phenomenon, will make contact be oxidized and ablation, thereby and may make airborne organic carbonization produce carbon distribution, make the contact resistance of switch increase even and open circuit gradually.
Fusing point with tungsten in various simple metal is the highest.Fusing point is higher than the simple metal of 1850 ℃ respectively: tungsten (3410 ℃ of fusing points), rhenium (3180 ℃ of fusing points), osmium (3045 ℃ of fusing points), tantalum (2996 ℃ of fusing points), molybdenum (2610 ℃ of fusing points), niobium (2468 ℃ of fusing points), hafnium (2227 ℃ of fusing points), vanadium (1900 ℃ of fusing points), chromium (1875 ℃ of fusing points) and zirconium (1852 ℃ of fusing points).Refractory metal has lower vapour pressure, has lower evaporation rate under vacuum high-temperature.The vapour pressure that refractory metal is lower and evaporation rate are that we select their alloy as a Consideration of slider material.
The preparation method of refractory metal alloy has powder metallurgic method, vacuum arc melting method and vacuum electronic bombardment smelting process etc.Most widely used general with powder metallurgic method, because simply also obtaining the alloy billet that crystal grain is tiny, this method technique is conducive to further plastic working.Powder metallurgic method main technique is: refractory metal powder (for example tungsten powder and molybdenum powder) is carried out to mechanical mixture to scale; By mechanical press or isostatic pressing machine, be pressed into former base; In the high temperature sintering furnace of logical hydrogen, sinter alloy billet into again.Sintering temperature improves with the increase of W content, and its scope is between 2150～2300 ℃.Finally sintering billet is become a useful person through rolling or forging.The alloy of preparing refractory metal by these methods, all needs comparatively expensive equipment, and the shape of prepared refractory metal alloy also has shape.Adopt the most widely used powder metallurgic method, the more difficult thin slice (particularly tungsten alloy thin slice) that makes the refractory metal alloy that thickness is less.If by the thin slice of thicker refractory metal alloy, be directly used in production hard contact, not only will increase the cost of raw material of hard contact, and because the hardness of refractory metal alloy is large, cut apart or Punching Technology difficulty.
The number of applying for a patent is that the patent document of 201220499100.X discloses " a kind of three-layered composite electric contact ", this contact is on the contact-making surface of copper base contact bodies, to plate one deck silver, make the electric conductivity of contact better, and will save production cost than adopting silver to make completely.Although conductivity and the conductivity of heat of silver are all the highest in all metals, the atmospheric corrosion resistance of silver is poor, salt spray resistance is poor.Hydrogen sulfide (the H of silver easily and in atmosphere
2s) reaction generates the silver sulfide of black.Silver is used as some contact, although initial surface resistance is little, be also restricted its useful life in atmosphere.Although silver-plated cost compare is low, silver is also one of noble metal.In addition, in such electric contact, there is no rubber layer, therefore, thereby this electric contact is unsuitable for carrying out with rubber, heat cure is bonding makes with heat cure moulding the rubber key that contains electric contact.The contact of only containing rubber layer, or the contact all being formed by conductive rubber, thereby just may be smoothly carry out the bonding and heat cure moulding of heat cure with other rubber, make the rubber key that contains contact, and can be in heat cure do not produce the quality problems such as excessive glue, Poor cohesion in bonding and heat cure forming process.
The number of applying for a patent is that 200580045811.2 patent document discloses a kind of " flat primary battery with gold plated terminal contacts ", and this battery can be used for for example digital camera.This battery can have anode and the low-resistance contact that comprises lithium.Anode and negative electrode can be therebetween the sheet form with the spirality crimping of dividing plate.Outside positive and negative contact with golden plating to improve contact resistance.Though the resistance of this invention electric contact is little, but because the fusing point of gold is not as good as refractory metals such as tungsten, molybdenums, so the spark performance that its proof voltage produces is not good enough.In addition, gold fancy price has also limited the range of application of this electric contact.
The number of applying for a patent is that 201020143455.6 patent document discloses a kind of " nickel-plated tungsten contact ", belongs to basic electrical component technical field, is intended to solve existing tungsten point oxidizable, affects the problem of electric conductivity.In known technology, existing tungsten point is mainly that rivet type seat nail and tungsten sheet be take fine copper and be made into as scolder melting welding.In this patent, adopt the present nail tungsten point outer surface ladle cover soldered with tungsten sheet to be connected the tungsten point of nickel plating that nickel coating consists of.It is simple and practical, and electric conductivity is stable, durable in use, is applicable to the electrical equipment such as automobile, motorcycle, electric horn.The contact of this patent adopts the additional nickel coating of tungsten sheet, but the arc ablation resistance performance of nickel is low, should not be for operating current or the larger harsher occasion of voltage.Our test shows, nickel contacts with the gold plated contact of PCB and disjunction (Kai Heguan) as switch contact, at room temperature, but operating current is 300 MAHs, after 4000 left and right of on-off times, the contact resistance of switch just significantly raises, and even makes circuit open circuit completely.
United States Patent (USP) 7169215 discloses the materials and methods of chemical deposition copper molybdenum alloy, the copper molybdenum alloy resistivity of resulting alkali-free metal ion and alkaline-earth metal ions lower than 30 microhms/centimetre.This alloy deposition is on single silicon wafer, on silicon thermal oxidation layer, on copper and cobalt thin film on silicon substrate.This copper molybdenum alloy can be used as the barrier layer of metal interlevel and the interconnection material on chip.Although this copper molybdenum alloy can replace copper in these application, resistivity is higher than copper.In this invention, disclose palladium solution activation for base material, then allowed copper molybdenum on various base materials, carry out chemical deposition.This invention does not relate to selective chemical deposition.The poor-performing of the arc ablation resistance of this copper molybdenum alloy is not the slider material of desirable arc ablation resistance.
United States Patent (USP) 4019910 discloses the chemical plating fluid of preparing a kind of polymetallic nickel alloy.In this nickel alloy, except containing boron or phosphorus, also contain one or more metal as tin, tungsten, molybdenum or copper.The ester complexes that contains inorganic acid and polyacid or polyol reaction gained in this chemical plating fluid, as two boron esters, wolframic acid ester or the molybdates esters of glucoheptonic acid.This nickel alloy is mainly comprised of nickel, nickel content conventionally about 60% to about 95%(weight ratio) scope in.This alloy has good mechanical performance and decay resistance, and wherein some alloy, as phosphorous nickel alloy, particularly nickel-phosphorus-tin-copper alloy, has non magnetic or nonferromagnetic.Boron or phosphorus that the disclosed polymetallic nickel alloy of this invention contains larger content, as used as slider material, the boron of larger content or the existence of phosphorus, by the initial resistance of influencing contactor.Our test shows, the nickel alloy that pure nickel, nickel alloy (as monel or monel metal, nichrome etc.) that nickel content is large, nickeliferous stainless steel or the nickel obtaining by chemical plating are chief component, if as the contact of switch, all there is poor arc resistance energy and lower switch useful life.
U.S. Patent application 20090088511 discloses the chemical plating fluid that optionally forms a kind of cobalt-base alloys diaphragm on exposed copper cash.Cobalt ions and another kind of metal ion (tungsten and/or molybdenum), chelating agent, reducing agent, specific surfactant and tetra-alkyl ammonium hydroxide in chemical plating fluid, have been comprised.Use this to invent disclosed plating solution, need to before chemical plating, not use a Seed Layer (as palladium layer).This diaphragm has non-proliferation, anti-electromigratory ability.But this diaphragm is because cobalt content is high, harder and crisp, because being easy to produce cobalt oxide, cobalt-base alloys under arcing cause sheet resistance to rise.This diaphragm arc ablation resistance performance is bad, should not be used for making electrical contact or contact.
U.S. Patent number is 6797312 invention, described with the plating solution of alkali-free metal and formed cobalt tungsten alloy, in plating solution, can not use Tetramethylammonium hydroxide, at deposit cobalt tungsten metal alloy to before on base material, without catalyst, as palladium catalyst pretreating substrates, use this plating solution just can obtain the sedimentary deposit of cobalt tungsten alloy.In this cobalt tungsten alloy, contain a large amount of cobalt elements, not resistance to switching arc ablation.How this invention of this alloy carries out optionally chemical deposition if also not relating to.
The invention that the patentee's the number of applying for a patent is 201110193369.5 provides a kind of " pitted skin metal and rubber combined conductive particle ", is bonded, or cuts and form after bonding by metal faced with rubber matrix.Metal faced is pitted skin, has pit, salient point or both all have; Pit or salient point all have on metal faced outer surface, inner surface or two surfaces.The degree of depth of pit is less than metal faced thickness, and the height of salient point is not less than 1/10th of metal faced thickness.Metal faced material is metal or alloy, and outer surface can plate gold, silver, copper or nickel etc.; Rubber matrix is silicon rubber or polyurethane rubber etc.; Between metal faced and rubber matrix, can have adhesive linkage, adhesive linkage is heat vulcanizate stick, silane coupling agent or is the material identical with rubber matrix.Metal faced inner surface can scribble the auxiliary agents such as coupling agent.Metal faced intensity of the present invention is high, stable conductivity, and adhesive linkage intensity is high, rubber matrix elasticity foot.This invention does not propose solution for solving the arc ablation resistance problem of conductive particle.This invention does not have to propose how on metal faced outer surface, to obtain the concrete grammar of one or more layers coating yet.On the pitted skin of this invention, gold-plated silver waits noble metal, and because surface area is large, noble metal dosage is many, and cost is high.
Summary of the invention
The first goal of the invention: overcome gold-plated, the money base of tradition or the silver-plated defect that switch contact cost is higher, arc resistance is not too high, or overcome copper base, Ni-based or although stainless steel contact cost is lower but shortcoming that arc resistance is poor, provides that a kind of low cost of manufacture, conduction property are good, the switch contact containing refractory metal alloy coating of arc ablation resistance.
The first technical scheme: a kind of switch contact containing refractory metal alloy coating provided by the invention; switch contact is the layered composite with three layers of layer structure; as small column grain, prism grain or cylindroid grain; ground floor is the hydrophobic rubber layer that 0.1-10mm is thick; the second layer is the layer of metal foil that 0.01-1.0mm is thick, and the 3rd layer is 2*10
-5the chemical deposition layer of the refractory metal alloy that-0.02mm is thick; Wherein, the chemical deposition layer of the 3rd layer of refractory metal alloy is in the chemical plating fluid of the complex of ground floor and the second layer compound that is immersed in the refractory metal that contains at least one solubility, and the surface that by the method for chemical deposition, the coating of refractory metal alloy is deposited on to the second layer in the complex of ground floor and the second layer forms; In the 3rd layer or account in the extexine of the 3rd layer of gross thickness 1/3rd, the percentage by weight sum of tungsten, rhenium, osmium, tantalum, molybdenum, niobium, hafnium, vanadium, chromium, zirconium, is not less than 50%; In the 3rd layer of refractory metal alloy layer, contain combination in any, percentage by weight that percentage by weight is no more than 50% transition metal iron, nickel, cobalt, copper, manganese or these elements and be no more than 10% tin, antimony, lead or bismuth or the combination in any of these elements.
Tungsten is to prepare the element that refractory metal alloy coating is preferentially selected, so that coating obtains good arc ablation resistance performance.In the refractory metal element except tungsten, preferentially select fusing point molybdenum element higher, that toxicity of compound is less, market supply is more sufficient and price is lower, with the alloy of tungsten formation refractory metal, namely tungsten-molybdenum alloy, or molybdenum and tungsten alloy.In addition, can make to contain in coating the refractory metal elements such as rhenium, osmium, tantalum, molybdenum, niobium, hafnium, vanadium, chromium or zirconium.When preparing refractory metal alloy, can use one or more chemical plating fluid, make in the coating of refractory metal, the percentage composition of W elements or other refractory metal element is stepped variation with thickness of coating.In the outer surface of refractory metal alloy coating, contain percentage by weight and be not less than 50% refractory metal element, to guarantee that coating has good arc ablation resistance performance.
Tungsten-molybdenum alloy can be used at than pure molybdenum or the higher temperature of molybdenum alloy.When made electrode, head piece and thimble parts with molybdenum and tungsten alloy in the ripple of producing high-melting-point refractory ceramic fibre is had a rest stove, its useful life is more much longer than simple metal molybdenum product.Molybdenum and tungsten alloy because fusing point is high, the flame erosion of Burning corrosion resistance energy and anti-solids is good, also can be used for the parts such as the jet vane of solid propellant rocket and backplate.Tungsten-molybdenum alloy combines some advantages of tungsten and some advantages of molybdenum.Therefore, this alloy can be applied in the wide temperature range between molybdenum and tungsten.These factors are also in the present invention, preferentially to adopt tungsten-molybdenum alloy as the reason of slider material.Adopt this alloy as slider material, can to a certain extent, by the good arc ablation resistance performance of tungsten and the workability energy of molybdenum, combine.
The ion that adds the transition metals such as iron, nickel, cobalt, copper, manganese in the plating solution of refractory metal alloy, is in order to make coating and metal base bonding firmly, and in order to accelerate the speed of chemical deposition.In plating solution, can also add the ion of the elements such as tin, antimony, lead or bismuth, so that coating obtains specific performance.Such as, in plating solution, add a small amount of stannous ion, or add stannous ion, antimony ion and lead ion simultaneously, can make the hardness of coating decline.Owing to having used the reducing agent of phosphorous or boracic, a small amount of phosphorus also may be deposited in coating.But because the content of phosphorus in coating and boron is high, the initial surface resistance that is coating is increased, therefore, should take to control the measures such as the concentration of reducing agent in plating solution and bath temperature, control the content of phosphorus and boron in coating.
Described ground floor is the hydrophobic rubber layer that 0.1-10mm is thick.Hydrophobic rubber layer is made by hydrophobic rubber.Hydrophobic rubber has repulsion ability to glassware for drinking water, and water can not come at hydrophobic rubber surface spreading.In order to obtain the selective chemical deposition of refractory metal alloy on metal material, the hydrophobicity of the quality of rubber materials in the complex by ground floor hydrophobic rubber layer and second layer metal thin slice is more high better.When carrying out chemical deposition with aforementioned plating solution, for the alloy that makes to be deposited on ground floor hydrophobic rubber layer is negligiblely few, the water contact angle of rubber substrate need be greater than 65o.Hydrophily rubber, the elastomeric material that contains surfactant or antistatic agent, the elastomeric material that contains a large amount of hydrophilies or water absorption filler, should not be used in the present invention.If use these elastomeric materials, when carrying out chemical plating, will the alloy of refractory metal be also deposited on these elastomeric materials.In general, the hydrophobicity of elastomeric material used is stronger, is more conducive to refractory metal alloy and uses in the present invention on the metal covering in rubber-metal stratiform compound and carry out selective chemical deposition, and on the surface of elastomeric material, do not deposit.The acrylonitrile-butadiene rubber of high nitrile group content and hydrogenated nitrile-butadiene rubber, carboxyl end of the liquid acrylonitrile-butadiene rubber, chlorosulfonated polyethylene rubber, epichlorohydrin rubber, acrylate rubber, polyurethane rubber isopolarity rubber, and the polarity of the material such as the rubber of hydrophiling (as hydrophily silicon rubber) and water-expansible rubber is large or contain a large amount of hydroaropic substances, surface hydrophobic is not strong.These materials are in the chemical plating fluid of the compound containing solubility refractory metal, and the coating of refractory metal will be deposited on the surface of these materials.
As optimization: described hydrophobic rubber layer is because carboxyl, hydroxyl, carbonyl, amino, amide groups, itrile group, nitro, halogen, sulfydryl, sulfonate radical and benzene sulfonic acid radical content on rubber molecular chain are low, thereby the elastomeric material that makes the water contact angle of rubber surface be greater than 65o forms; Or, described hydrophobic rubber layer be due in rubber not containing or contain a small amount of hydrophilic filler or additive, thereby the elastomeric material that makes the water contact angle of rubber surface be greater than 65o forms.Elastomeric material is heat cured or thermoplastic.
As further optimization: described hydrophobic rubber layer is prepared from by ethylene propylene diene rubber, methyl vinyl silicone rubber or methyl ethylene phenyl siloxane rubber.Ethylene propylene diene rubber, methyl vinyl silicone rubber and methyl ethylene phenyl siloxane rubber are non-polar rubbers, hydrophobicity is strong, their good weatherability can keep for a long time good elasticity in atmosphere simultaneously, is suitable for carrying out compound preparation layered composite with sheet metal.When the chemical plating fluid of stating before use carries out chemical plating, chemical deposition does not occur on rubber layer.Therefore, they are materials of the preferential use of described hydrophobic rubber layer.
Here so-called selective chemical deposition, refers to refractory metal alloy coating, is optionally deposited on metal material, and is not deposited on quality of rubber materials.Carboxyl, hydroxyl, carbonyl, amino, amide groups, itrile group, nitro, halogen, sulfydryl, sulfonate radical and benzene sulfonic acid root on rubber molecular chain, will increase polarity and the hydrophily of rubber.Particularly carboxyl, hydroxyl, sulfonate radical and benzene sulfonic acid root, will increase polarity and the hydrophily of rubber greatly.If what use in the complex of rubber and metal is hydrophilic carboxylic rubber, chemical deposition will both can occur in metal surface, also occurred in quality of rubber materials surface simultaneously.If there is the sedimentary deposit of refractory metal alloy on quality of rubber materials, the plating solution of chemical plating will not only be wasted, and the heat cure that is unfavorable for quality of rubber materials and other quality of rubber materials is bonding or thermoplastic bonded, and this heat cure is bonding or thermoplastic bonded is necessary in following process.The existence of ground floor hydrophobic rubber layer, is for ground floor hydrophobic rubber layer and other rubber carry out the bonding or thermoplastic bonded of heat cure, thereby can prepares the rubber key that comprises contact.
Therefore, the essential content of these above-mentioned polar groups in rubber substrate that limits, to obtain selective chemical deposition.In order to obtain the chemical deposition of selectivity the best, in rubber substrate, can not contain these groups.Same reason, quality of rubber materials body or surface do not contain or contain on a small quantity filler, additive, antistatic agent or the surfactant that hydrophily is strong, are also conducive to obtain the chemical deposition that selectivity is good.
As optimization: the layer of metal foil of the described second layer is the metal sheet with salient point or concave point, have convex line bar or concave bar metal sheet, have convex surface or concave surface metal sheet, there is area and be less than 1mm
2metal sheet, wire netting, metal foam or the metallic fiber sintered felt of aperture so that larger with the contact footprint pressure on PCB, conduction is better; Metal material is magnesium, aluminium, titanium, chromium, manganese, iron, cobalt, nickel, copper, zinc, niobium, molybdenum, silver, tin or alloy golden or that contain these elements; The sheet metal of the second layer be single metal material or different metal materials stratiform compound; The metal or alloy that preferably conductivity is higher and price comparison is low.
As optimization: the sheet metal of the described second layer consists of the thick stainless steel of 0.01-1.0mm, copper or copper alloy, nickel or nickel alloy thin slice, at the one or both sides of stainless steel, copper or copper alloy, nickel or nickel alloy thin slice, be coated with pure-nickel-layer or the nickel alloy layer of 0.1-10 micron; Nickel alloy layer on stainless steel, copper or copper alloy, nickel or nickel alloy thin slice is to be prepared by the method for vacuum coating, plating or chemical plating.On stainless steel, copper or copper alloy, nickel or nickel alloy thin slice, plate a pure-nickel-layer or nickel alloy layer, can improve the bonding strength of sheet metal and refractory metal alloy coating, avoid refractory metal alloy coating to come off in the use procedure of contact.Particularly copper and copper alloy thin slice should plate skim pure-nickel-layer or nickel alloy on the two sides of copper and copper alloy thin slice, to improve the resistance to oxidation of copper and copper alloy, the performance of resistance to chemical attack before chemical deposition refractory metal alloy coating.
Thereby above-mentioned stainless steel is common stainless steel, acid resisting steel or the special stainless steel that has added the corrosion that improves atmospheric corrosion resistance, the particularly atmosphere of resistance to chloride of tungsten element.
The thickness of sheet metal should not be excessively thin.If the sheet metal thickness of the second layer, lower than 0.01mm, just can not support the refractory metal alloy coating of the 3rd layer well, with rubber combined before, among or in processing afterwards, easily break.If the sheet metal of the second layer is too thick, will increase the integral hardness of contact, cut apart or Punching Technology become difficulty, waste metal material simultaneously.So the thickness of sheet metal, should not be greater than 1.0mm.
In advance the hydrophobic rubber layer of ground floor and the sheet metal of the second layer being made to layered composite, is using layered composite as contact application in preparing rubber key for convenient.Hydrophobic rubber in layered composite, can be directly and other rubber carry out the bonding or thermoplastic bonded of heat cure and form rubber key.If will have the sheet metal of rubber layer and other rubber to carry out the bonding or thermoplastic bonded of heat cure, do not form rubber key, excessive glue phenomenon will occur in moulding process.The so-called glue phenomenon of overflowing, refers in moulding process, rubber overflows to the front of contact, thus the electric conductivity of influencing contactor.On contact, having excessive glue phenomenon, is unacceptable to the quality of contact.
The second goal of the invention: a kind of preparation method that the above-mentioned switch contact containing refractory metal alloy is provided.
The second technical scheme: a kind of preparation method of the switch contact containing refractory metal alloy, comprises the steps:
(1) processing of layer of metal foil: layer of metal foil is stainless steel, copper or copper alloy, nickel or the nickel alloy thin slice that 0.01-1.0mm is thick, at the one or both sides of stainless steel, copper or copper alloy, nickel or nickel alloy thin slice, or by the method for vacuum coating, plating or chemical plating, be coated with pure-nickel-layer or the nickel alloy layer of 0.01-10 micron; Preferentially select the method for chemical plating to prepare nickel alloy layer;
(2) adhesion process of hydrophobic rubber layer and layer of metal foil: hydrophobic rubber layer, by heat cure moulding, is bonded in the layer of metal foil that scribbles silane coupling agent or adhesion promotor, forms composite sheet; Or will there is tack hydrophobic rubber, by heat cure moulding, be bonded in the layer of metal foil that scribbles silane coupling agent or there is no silane coupling agent, form composite sheet;
(3) cutting process: the composite sheet in above-mentioned steps cut apart or be die-cut into the cylinder that diameter is 2-10mm, cleaning approximately 5 minutes with alkaline cleaning fluid, washing, then uses 5% hydrochloric acid cleaning 3 minutes, then cleans up with deionized water, drains; The object of the hydrochloric acid cleaning with 5%, is the oxide for remove portion metallic substrate surface, makes metallic substrate surface activation, strengthens the bond strength between metal base and refractory metal alloy coating.Using other to clean and acid solution activation method, is also feasible.
(4) preparation of refractory metal alloy coating: by above-mentioned cylinder, be immersed in and contain in solubility refractory metal compound chemistry plating solution, stir, form refractory metal alloy coating by the method for chemical plating; Or, above-mentioned cylinder is put into the cylinder of the chemical plating fluid that contains solubility refractory metal compound, allow cylinder rotate, in the metal surface of small cylinder, form refractory metal alloy coating;
The soluble tungsten that contains 20-150g/L in plating solution, rhenium, osmium, tantalum, molybdenum, niobium, hafnium, vanadium, the compound of chromium or zirconium or the combination in any of these compounds, the transition metal iron of the solubility of 0-60g/L, nickel, cobalt, the compound of copper or manganese or the combination in any of these compounds, the tin of the solubility of 0-30g/L, antimony, the combination in any of lead or bismuth compound or these compounds, the reducing agent of 20-150g/L, the complexing agent of 30-150g/L, the pH value conditioning agent of 20-100g/L, the stabilizer of 0.1-1g/L, the surfactant of 0.1-2g/L, the brightener of 0-50 g/L or roughness conditioning agent, also can in plating solution, add other auxiliary agent, as chemical plating accelerator.Accelerator can be selected sodium fluoride.Sodium fluoride both can be used as accelerator, can also increase the brightness of coating simultaneously;
When adopting inferior sodium phosphate as reducing agent, the temperature of refractory metal alloy chemical plating that coating adopts is 65-80 ℃, and the time is 45-270 minute, and the pH value of plating solution is 8.5-9.5.
(5) clean, dry: after taking-up by distilled water or rinsed with deionized water, drain, cold wind dries up or be placed in the constant temperature oven of 70 ℃ and dry, and obtains the metal faced switch contact that is coated with refractory metal alloy.
In the present invention, described soluble tungsten compound is one or more in sodium tungstate, potassium tungstate, ammonium tungstate, ammonium metatungstate, sodium phosphotungstate, wolframic acid, tungstic acid.Select while being insoluble to the wolframic acid of pure water or tungstic acid as tungsten source, first with NaOH aqueous slkali, wolframic acid or tungstic acid are dissolved, then with lysed wolframic acid or tungstic acid, configure chemical plating fluid.Preferentially select the sodium tungstate that is easy to dissolve and price valency is low to prepare chemical plating fluid.Described soluble molybdenum compound is sodium molybdate, potassium molybdate, ammonium molybdate, phosphomolybdic acid, ammonium phosphomolybdate, molybdic acid, molybdenum trioxide.When use is slightly soluble in the molybdic acid of water or water-fast molybdenum trioxide as molybdenum source, can first with sodium hydroxide solution, it be dissolved, then with it, prepare chemical plating fluid.The soluble compound of other described refractory metal comprises perrhenic acid sodium, potassium perrhenate, ammonium perrhenate, potassium osmate, tantalum hydroxide or hydration tantalum pentoxide, potassium floutaramite, potassium niobate, aqua oxidation niobium, dichloro hafnium oxide eight hydrates, six potassium fluohafnates, sodium vanadate, sodium metavanadate, sodium orthovanadate, ammonium metavanadate, alum acid anhydrides, potassium bichromate, chrome green (dissolving with alkali lye before using), Potassium Zirconium Fluoride, zirconyl nitrate etc.
Described soluble nickel compound is one or more in nickelous sulfate, nickel chloride, nickel nitrate, ammonium nickel sulfate, basic nickel carbonate, nickel sulfamic acid, nickel acetate, nickelous hypophosphite.While using nickel hydroxide, first with ammoniacal liquor, make it to dissolve.We find during tungsten-molybdenum alloy in plating, but in chemical plating fluid the precursor of nickel use nickelous sulfate and basic nickel carbonate composite, can make to plate tungsten-molybdenum alloy layer there is brighter silvery white, the sheet resistance of gained tungsten-molybdenum alloy coating is lower.Described solubility cobalt compound is one or more in cobaltous sulfate, cobalt chloride, cobalt nitrate, ammonium cobaltous sulfate, basic cobaltous carbonate, sulfamic acid cobalt, cobalt acetate, cobalt oxalate.One or more in described soluble copper compound copper sulphate, copper chloride, copper nitrate, hydration basic copper carbonate, copper acetate.
The compound that can add nickel, cobalt, copper other soluble transition metal element in addition in plating solution, and the tin compound of solubility, antimonial, bismuth compound and lead compound, but should note the optionally impact on deposited base material on chemical plating of these compounds.In addition also to note, physiology toxicity, environmental toxicity and the hazard property of these compounds.Such as, should use less maybe need not be to human body and the harmful soluble lead compound of environment as far as possible.Although silver is element conventional in electrical contact or contact, do not advise adding the silver soluble compounds such as silver nitrate in tungsten-molybdenum alloy plating solution.Because we find in experiment, in tungsten-molybdenum alloy plating solution, add after a certain amount of silver nitrate (as 5g/L), when the layered composite of the layer of metal foil of the hydrophobic rubber layer of ground floor and the second layer is carried out to chemical plating, the chemical deposition occurring, to not occur over just in the layer of metal foil that the second layer is, also occur on the hydrophobic rubber layer of ground floor, chemical deposition has not just had selectivity to base material like this.When sedimentation time long enough, with the naked eye just can be clear that on hydrophobic rubber layer He in layer of metal foil and have grey black or argenteous sedimentary deposit.Use X-ray fluorescence spectra analysis, a large amount of silver is all contained on the discovery surface of layer of metal foil and the surface of hydrophobic rubber layer.Use same formula to cancel after adding of silver nitrate,, in the process of chemical plating, chemical deposition layer is only created on the metal covering of layer of metal foil.
Described reducing agent is one or more in inferior sodium phosphate, sodium borohydride, alkylamine borine, hydrazine, titanium trichloride.If take boron hydride or amino borane during as reducing agent, will contain a small amount of boron (mass fraction can reach 7%) in tungsten-molybdenum alloy coating.With hydrazine, make reducing agent, the content of nonmetal in resulting coating (phosphorus or boron) is almost nil, and tenor can reach more than 99%.While selecting inferior sodium phosphate to be reducing agent, owing to there being phosphorus to separate out, there is the codeposition of phosphorus and metal, in coating, apart from metallic element, also contain a small amount of phosphorus outward.Phosphorus is harmful to the conductivity of contact, and may injure the decay resistance of refractory metal alloy, therefore, and the essential phosphorus content of controlling in tungsten-molybdenum alloy.By controlling the concentration of inferior sodium phosphate, the measures such as the concentration of complexing agent, pH value can be controlled the phosphorus content in coating.Control the coating that phosphorus content can obtain the refractory metal alloies such as tungsten-molybdenum alloy of densification, atresia.The preferential inferior sodium phosphate that price is lower and toxicity is lower in the present invention.Select inferior sodium phosphate as reducing agent, contact resistance between our resulting tungsten-molybdenum alloy coating, than nickel content, be that more than 99.5% pure nickel and nickel content are that contact resistance between 99.5% above pure nickel is little, resulting coating can significantly improve the resistance to switching arc performance of metal base.Select inferior sodium phosphate to have good cost performance as reducing agent.For tin ion or stannous ion in plating solution are deposited in coating, need to use the stronger titanium trichloride (TiCl3) of reproducibility to make reducing agent, add some suitable complexing agent as citrate or EDTA simultaneously.
Described complexing agent is one or more in natrium citricum, ammonium citrate, sodium tartrate, sodium potassium tartrate tetrahydrate, disodium EDTA, tetrasodium salt of EDTA.The effect of complexing agent is to control to improve bath stability for the concentration of the free metal ion reacting, and extends bath life, improves quality of coating.Complexing agent all has impact to deposition rate, phosphorus content and corrosion resistance etc.
When adopting inferior sodium phosphate as reducing agent, the pH value of plating solution is preferably 8.5-9.5.Due in electroless plating reaction process, the hydrionic generation of accessory substance, causes bath pH value to decline.Use, in the process of chemical plating, need to supplement pH adjusting agent.Described pH adjusting agent is one or more in NaOH, potassium hydroxide, sodium carbonate, ammoniacal liquor, sodium pyrophosphate, sodium acetate, potassium pyrophosphate.The preferential pH value of using ammoniacal liquor or sodium hydroxide solution to regulate plating solution.Can obtain like this adhesion more by force, more stable, the better tungsten-molybdenum alloy coating of quality of coating.The price of ammoniacal liquor or sodium hydroxide solution is also more cheap.When adopting inferior sodium phosphate as reducing agent, pH value can not be greater than 12, although because too high pH accelerates deposition velocity, make the adhesive force variation between coating or sedimentary deposit and metal base, makes darkening of coating or sedimentary deposit, even becomes black.For stable plating speed and assurance quality of coating, plating solution must possess buffer capacity, and the pH value of plating solution is maintained in suitable scope.Therefore, in plating solution, contain strong base-weak acid salt as pH value buffer.
When not considering color, gloss, described stabilizer is KI, Potassiumiodate, benzotriazole, 4,5-bis-sulfo-octane-1, the mixture of one or more in 8-disulfonate, 3-sulfydryl-1-propane sulfonic acid salt, sodium thiosulfate, thiocarbamide.Described brightener (or surface roughness conditioning agent) can be one or more in other commercially available chemical plating brightener.When considering color, gloss, described stabilizer is preferably sodium thiosulfate, thiocarbamide or both mixtures, makes refractory metal alloy coating have good metallic luster simultaneously.Thereby the effect of stabilizer is the self-catalyzed reaction that suppresses to occur in chemical plating process stablizes plating solution, prevents fierce self-catalyzed reaction, prevent from generating a large amount of phosphorous ferrous metal powder.But stabilizer is the poisonous agent of chemical plating, i.e. anticaltalysis reaction, so can not excessively use, needs to control its consumption in plating solution, in order to avoid affect chemical plating efficiency.
In the plating solution that described chemical plating adopts, also contain the surfactant of 0.1-1g/L; Described surfactant is: the surfactant of one or more in dodecyl benzene sulfonate, lauryl sulfate, n-octyl sodium sulphate; Be preferably: lauryl sodium sulfate or neopelex.Add a little surfactants to contribute to overflowing of plating piece surface gas, reduce the porosity of coating, make coating fine and close, thereby increase the arc resistance energy of coating.
Described brightener or roughness conditioning agent are formaldehyde, acetaldehyde, cumal, chlorobenzaldehyde, betanaphthol, 2-methyl aldehyde anil, benzylideneacetone, benzophenone, peregal, western Buddhist alkali, butynediols, propilolic alcohol, 1-diethylin third-2-alkynes, ethoxyquin propilolic alcohol, saccharin, benzoic sulfimide sodium, sodium vinyl sulfonate, propine sodium sulfonate, pyridine-2-hydroxy-propanesulfonic acid inner salt, one or more in APES or commercially available commercial chemical plating brightener.Can use two or more brightener composite simultaneously, to increase the brightness effect of coating, reduce the consumption of brightener.
The time of chemical plating selected, requires relevant with performance requirement or the useful life of the arc ablation resistance of switch product.The time of chemical plating is longer, and the refractory metal alloy coating being deposited on metal base will be thicker.Thicker refractory metal alloy coating is conducive to the resistance to switching arc performance of contact.But the time of chemical plating is not that the longer the better.The overlong time of chemical plating, not only production efficiency is low, and with alkaline chemical plating fluid, may injure the hydrophobic rubber layer of ground floor and the bonding strength between the layer of metal foil of the second layer, even causes delamination.As preferably, if required, under the On current of 500mA, on-off times can be more than 10,000 times, and the time of described refractory metal alloy chemical plating that coating adopts is 200 minutes.The temperature of rising chemical plating fluid, can make the speed of chemical deposition accelerate, but too high bath temperature (higher than 90 ℃), will the darkening of chemical deposit, coating be declined to the adhesive force of metal base.
In the present invention, use the complex of hydrophobic rubber layer and layer of metal foil, with above-mentioned plating solution, carry out chemical plating, can make refractory metal alloy coating be deposited on metallic surface.We detect the refractory metal constituent content of metal surface with Xray fluorescence spectrometer (XRF), can find, in same plating solution, along with the prolongation of chemical plating time, the refractory metal element signal detecting in metal surface is more and more stronger.Refractory metal element signal is more and more stronger, means that refractory metal alloy coating is more and more thicker along with the chemical plating time.Even but chemical plating is for up to 300 minutes, the refractory metal element signal detecting on hydrophobic rubber surface is also almost nil.
Beneficial effect: the present invention optionally plates the alloy of one deck refractory metal in the layered composite of hydrophobic rubber layer and sheet metal with the method for chemical plating, can improve conductivity and the resistance to switching arc ablation property of sheet metal effectively.The contact that is coated with refractory metal alloy layer being made by stainless steel substrates (as SS304 stainless steel substrates), nickel sheet (as N6 nickel sheet), nickel alloy sheet (as NCu30 monel sheet), contact with the gold plated contact on PCB, contact resistance between contact, less than the similar contact and the contact resistance between the gold plated contact on PCB that do not plate refractory metal alloy, there is good conduction property.By not plating the stainless steel substrates of refractory metal alloy or contact that nickel sheet makes and PCB gold plated contact by the direct current of 300 milliamperes, under room temperature continuously after about 2000-4000 time of switch, arc erosion owing to there is switch, contact resistance between the contact of being prepared by these metal materials and PCB gold plated contact just obviously raise (being increased to more than 100 ohm not even conducting by approximately 1 ohm); And under same circuit condition, by the present invention, being coated with the similar contact of tungsten-molybdenum alloy and PCB gold plated contact by the direct current of 300 milliamperes, after switch approximately 10000 times, the contact resistance between contact and PCB contact, still below 1 ohm.
The contact of this plating refractory metal alloy, cost is lower.With the switch contact comparison that is coated with gold or silver, can bear larger electric current by obtaining, there is better arc ablation resistance performance.And the tungsten of preferentially selecting, the price of Mo are far below gold, platinum or silver.In this contact that is coated with refractory metal alloy coating, because available molybdenum element has replaced part W elements, prepare the cost of raw material used also lower.
Regulate the formula of plating solution to form and time and the temperature of chemical plating, can there be the appearance effect such as color, gloss that are similar to yellow gold, silver, silver, steel or some titanium nitride the contact of containing refractory metal alloy coating of gained.Product of the present invention is applicable to the various low-voltage electrical apparatuses that switch had to strict demand useful life, is particularly suitable for making in the electric appliance and electronic equipment such as automobile, electric tool, game machine, needs connection, carrying and disjunction to be greater than the switch contact of the electric current of 50mA.
The contact of preparing in the present invention, contains hydrophobic rubber layer.The surface of hydrophobic rubber layer, does not deposit the alloy of refractory metal.The existence of hydrophobic rubber layer, is convenient to this contact and other rubber and carries out the bonding and heat cure moulding of heat cure, thereby make the rubber key product with contact.
Accompanying drawing explanation
Fig. 1 is a kind of cross-sectional view of the present invention;
Fig. 2 is a kind of process chart in preparation method of the present invention.
Wherein, in figure: 1, rubber layer; 2, layer of metal foil; 3, refractory metal alloy coating.
Embodiment
Below in conjunction with specific embodiment, the invention will be further described.
Embodiment 1:
Prepare a kind of switch contact containing refractory metal alloy coating:
Its plating solution consists of:
The preparation of plating solution: first above-mentioned various compound waters are dissolved or water heating for dissolving, be then mixed in proportion.With ammoniacal liquor adjust pH to 9.0, and be diluted with water to prescribed volume.
Process route:
As shown in Figure 1, 2, the 0.1mm of take is thick, the packfong sheet material of HV hardness as 120 to 180, copper content approximately 55% is metal base, as layer of metal foil 2.The reason of selecting packfong is because packfong has good comprehensive mechanical performance, excellent corrosion resistance, cold and hot working good moldability, is applicable to manufacture various flexible members.Level and smooth packfong sheet material is rolled into the sheet material of insertion waves shape by Mechanical Method, ripple peak height is 0.1mm, and peak separation is 0.2mm.Then with the alkaline cleaning fluid that pH value is 9 left and right, clean oil removing, washing, then with industrial alcohol, clean oil removing, then with 12.5% sulfuric acid solution, at the temperature of 50 to 80 ℃, clean 2 minutes, washing, then, two sides at the sheet material of packfong insertion waves shape, in the mode of chemical plating, the chemical nickel-plating plating solution with containing nickelous sulfate and inferior sodium phosphate, plates the nickel dam that thickness is about 2.5 microns.On metal base, chemical nickel plating is a kind of technique of maturation, not at this detailed description.The packfong sheet material that is coated with the insertion waves shape of nickel dam is cleaned up with deionized water, and cold wind dries up.
A kind of methyl ethylene phenyl siloxane rubber (the Elastosil R 401/60 that German Wa Ke company produces) and vinyl three tertiary butyl peroxy-silanes (VTPS) and cumyl peroxide (DCP) are even with mill mixing, as rubber layer 1.The content of VTPS in elastomeric compound is that the content of 1%, DCP in elastomeric compound is 0.5%.VTPS is a kind of coupling agent that contains unsettled per-compound composition, and it both can make the silicone rubber crosslinking containing vinyl, also promotes bonding containing between the silicon rubber of vinyl and metal (as nickel, carbon steel, stainless steel, copper etc.) simultaneously.
The packfong sheet material and the above-mentioned elastomeric compound that are coated with the insertion waves shape of nickel dam are carried out to bonding what the heat cure moulding of heat cure at 165 ℃, and cure time is 12 minutes.The packfong that formation 1.25mm is thick and the stratiform composite sheet of silicon rubber.The cavity surface that makes the mould of this composite sheet, has teflon coatings.The existence of teflon coatings, has prevented elastomeric compound sticking to mould in heat cure process.This composite sheet is die-cut into the sequin that diameter is 5mm.Alkaline cleaning fluid for this sequin is cleaned minute, and washing, then uses 5% salt acid soak 3 minutes, is finally placed in 10% dilute sulfuric acid and activates 1min, then cleans, and drains.
By 500 such sequins, put into the above-mentioned 600mL plating solution of 80 ℃, stir, after 200 minutes, take out, by distilled water or rinsed with deionized water, drain, cold wind dries up or be placed in the constant temperature oven of 70 ℃ and dry, and obtains the metal faced sequin that tungsten-molybdenum alloy is refractory metal alloy coating 3 that is coated with.In the process of chemical plating, should constantly note the pH value situation of change of solution, with ammoniacal liquor or sodium hydroxide solution, control in time the pH value of solution, pH value is remained between 8.5 to 9.5.
This sequin that is coated with tungsten-molybdenum alloy that contains silastic-layer, and silicon rubber carries out the bonding and heat cure moulding of heat cure.Silicone rubber in sequin and other silicon rubber heat cure are bonding, are coated with the one side of tungsten-molybdenum alloy layer outwardly, so that tungsten-molybdenum alloy layer can contact with the contact on printed circuit board (PCB) (PCB).After this sequin and silicon rubber heat cure moulding, can be made into rubber key.This sequin has been used as the contact that is used as contactor in rubber key just.This contact contacts with the gold plated contact on PCB, there is stable and lower contact resistance, and this sequin that is coated with tungsten-molybdenum alloy has better conducting stability: by there is no the packfong of tungsten-molybdenum alloy coating or be coated with sequin that the packfong of nickel dam makes and PCB gold plated contact by the direct current of 300 milliamperes, after switch approximately 3000 times, arc erosion owing to there is switch, contact resistance between sequin and PCB gold plated contact just obviously raise (be increased to more than 100 ohm by approximately 1 ohm, even can occur the situation of not conducting during test of many times); And under same circuit condition, this sequin that is coated with tungsten-molybdenum alloy and PCB gold plated contact be by the direct current of 300 milliamperes, after switch approximately 10000 times, the contact resistance between this sequin and PCB gold plated contact, still below 1 ohm.
Embodiment 2:
Prepare a kind of switch contact containing refractory metal alloy coating:
Plating solution forms:
The preparation of plating solution: first above-mentioned various compound waters are dissolved, can heat and accelerate dissolving progress.Wherein titanium trichloride available water or 10% dissolve with hydrochloric acid solution.The titanium trichloride solution of preparation can not be placed for a long time, to avoid precipitation.Except titanium trichloride solution and ammoniacal liquor, above-mentioned all solution is mixed to form to a mixed liquor in proportion; Liquor ferri trichloridi is joined in mixed liquor in proportion, and stir; With ammoniacal liquor adjust pH to 9.0, and be diluted with water to prescribed volume.
Process route:
The smooth stainless steel substrates (model 304) that 0.075mm is thick carries out alkaline degreasing and anode oil removing, and clean up, as layer of metal foil 2, simultaneously use a kind of rubber to metal adhesive (Megum 14135 that U.S. Rhom and Hass produces) to carry out primary coat processing it, then, this one side that primary coat was processed, to carry out heat cure bonding with a kind of methyl ethylene phenyl siloxane rubber (the Elastosil R 401/60 that German Wa Ke company produces), make rubber layer 1, form the thick stainless steel-silicon rubber composite sheet of 1.0mm.This composite sheet is die-cut into the sequin that diameter is 5mm.
This sequin is cleaned approximately 5 minutes with alkaline cleaning fluid, and washing, then uses 5% hydrochloric acid cleaning 3 minutes, then with deionized water, cleans up, and is filtered dry.
By 500 such sequins, put into the small-sized cylinder of above-mentioned 1000mL plating solution of 80 ℃, automatically, after 240 minutes, take out, by distilled water or rinsed with deionized water, drain, cold wind dries up, and must wait until the metal faced sequin that tungsten CoSn alloy is refractory metal alloy coating 3 that is coated with.In the process of chemical plating, should constantly note the pH value situation of change of solution, with ammoniacal liquor or sodium hydroxide solution, control in time the pH value of solution, make pH value again between 8.5 to 9.5.Tungsten CoSn alloy is the deposition of the stainless steel surfaces in sequin only, not the deposition of the silastic surface in sequin.In plating solution, added cobaltous sulfate rather than added nickelous sulfate.In chemical plating process, separating out of cobalt ions is slightly slower than separating out of nickel ion, so just both can utilize the existence arrival coating of cobalt element and the object of stainless steel substrate good bonding, can reduce in coating and have compared with the content of the transition metal of low melting point again.The object that adds stannous chloride in plating solution is in order to make to contain tin element in coating and to obtain softer chemical deposition layer.Softer chemical deposition layer, as the outer surface as a contact, by with another contact contacting with it (as the gold-plated contact on PCB) formed to contact more closely, and can reduce the wearing and tearing of another contact of contact with it.
This sequin that is coated with tungsten CoSn alloy, with silicon rubber heat cure bonding (silicone rubber in sequin and other silicon rubber heat cure bonding, be coated with the one side of tungsten CoSn alloy outwardly), can be as the contact that is used as contactor in rubber key, this contact contacts with the gold plated contact of printed circuit board (PCB) (PCB), the contact resistance of contact is lower than the sequin and the contact resistance between the gold plated contact of PCB that are directly made by stainless steel substrates, and this sequin that is coated with tungsten CoSn alloy has better conducting stability: the sequin being made by the stainless steel that there is no tungsten CoSn alloy coating and PCB gold plated contact are by the direct current of 500 milliamperes, after switch approximately 3000 times, arc erosion owing to there is switch, contact resistance between sequin and PCB gold plated contact just obviously raises and (by approximately 1 ohm, is increased to more than 100 ohm, during test of many times, even can there is the situation of not conducting), and under same circuit condition, this sequin that is coated with tungsten nickel and PCB gold plated contact be by the direct current of 500 milliamperes, after switch approximately 20000 times, the contact resistance between this sequin and PCB golden finger, still below 1 ohm.
Embodiment 3:
The 400 object stainless steel plain weave nets (stainless steel model is 304) of take replace the stainless steel substrates in embodiment 2, adopt technique and the chemical plating fluid implemented in 2, and prepared contact also has lower contact resistance and good arc ablation resistance performance.
400 object stainless (steel) wire mesh are very little, and when with silicon rubber moulded, silicon rubber can not penetrate the mesh of stainless (steel) wire.If select the stainless (steel) wire that order number is little, as the stainless (steel) wire below 80 orders, when mold pressing, will produce the technological problems that silicon rubber penetrates stainless steel mesh.Therefore, need to adopt the stainless (steel) wire of larger order number to prepare coated switch contact.
For those skilled in the art, under the premise without departing from the principles of the invention, can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.
Claims (10)
1. containing a switch contact for refractory metal alloy coating, it is characterized in that: switch contact is the layered composite with three layers of layer structure; Ground floor is the hydrophobic rubber layer that 0.1-10mm is thick, and the second layer is the layer of metal foil containing magnesium, aluminium, titanium, chromium, manganese, iron, cobalt, nickel, copper, zinc, niobium, molybdenum, silver, tin or gold that 0.01-1.0mm is thick, and the 3rd layer is 2*10
-5the chemical deposition layer of the refractory metal alloy that-0.02mm is thick; Wherein, the chemical deposition layer of the 3rd layer of refractory metal alloy is in the chemical plating fluid of the complex of ground floor and the second layer compound that is immersed in the refractory metal that contains at least one solubility, and the surface that by the method for chemical deposition, the coating of refractory metal alloy is deposited on to the second layer in the complex of ground floor and the second layer forms; In the 3rd layer of refractory metal alloy layer or account in the extexine of the 3rd layer of gross thickness 1/3rd, the percentage by weight sum of tungsten, rhenium, osmium, tantalum, molybdenum, niobium, hafnium, vanadium, chromium, zirconium, is not less than 50%; In the 3rd layer of refractory metal alloy layer, contain combination in any, percentage by weight that percentage by weight is no more than 50% transition metal iron, nickel, cobalt, copper, manganese or these elements and be no more than 10% tin, antimony, lead or bismuth or the combination in any of these elements.
2. the switch contact containing refractory metal alloy coating according to claim 1, it is characterized in that: described hydrophobic rubber layer is because carboxyl, hydroxyl, carbonyl, amino, amide groups, itrile group, nitro, halogen, sulfydryl, sulfonate radical and benzene sulfonic acid radical content on rubber molecular chain are low, thereby the elastomeric material that makes the water contact angle of rubber surface be greater than 65o forms; Or, described hydrophobic rubber layer be due in rubber not containing or contain a small amount of hydrophilic filler or additive, thereby the elastomeric material that makes the water contact angle of rubber surface be greater than 65o forms.
3. the switch contact containing refractory metal alloy coating according to claim 1 and 2, it is characterized in that: the rubber of described hydrophobic rubber layer a little less than by nonpolar or polarity is prepared from, and preferentially selects ethylene propylene diene rubber, methyl vinyl silicone rubber or methyl ethylene phenyl siloxane rubber.
According to described in claim 1 or 3 containing the switch contact of refractory metal alloy coating, it is characterized in that: described layer of metal foil is metal sheet, the metal sheet with convex line bar or concave bar, the metal sheet with convex surface or concave surface with salient point or concave point, have area is less than 1mm
2metal sheet, wire netting, metal foam or the metallic fiber sintered felt of aperture; Metal material is magnesium, aluminium, titanium, chromium, manganese, iron, cobalt, nickel, copper, zinc, niobium, molybdenum, silver, tin or alloy golden or that contain these elements; Described sheet metal be single metal material or different metal materials stratiform compound.
5. according to the switch contact containing refractory metal alloy coating described in claim 1 or 4, it is characterized in that: the sheet metal of described layer of metal foil consists of the thick stainless steel of 0.01mm to 1.0mm, copper or copper alloy, nickel or nickel alloy thin slice, at the one or both sides of stainless steel, copper or copper alloy, nickel or nickel alloy thin slice, be coated with pure-nickel-layer or nickel alloy layer, pure cobalt layer or the cobalt alloy layer of 0.01 micron to 10 microns; Pure-nickel-layer on stainless steel, copper or copper alloy, nickel or nickel alloy thin slice or nickel alloy layer, pure cobalt layer or cobalt alloy layer are to be prepared by the method for vacuum coating, plating or chemical plating.
6. contain a preparation method for the switch contact of refractory metal alloy coating, it is characterized in that: the preparation of switch contact comprises the steps:
(1) processing of layer of metal foil: layer of metal foil is stainless steel, copper or copper alloy, nickel or the nickel alloy thin slice that 0.01mm to 1.0mm is thick, at the one or both sides of stainless steel, copper or copper alloy, nickel or nickel alloy thin slice, by the method for vacuum coating, plating or chemical plating, be coated with pure-nickel-layer or nickel alloy layer, pure cobalt layer or the cobalt alloy layer of 0.05 micron to 10 microns;
(2) adhesion process of hydrophobic rubber layer and layer of metal foil: hydrophobic rubber layer, by heat cure moulding, is bonded in the layer of metal foil that scribbles silane coupling agent or adhesion promotor, forms composite sheet; Or by thering is the hydrophobic rubber of tack, by heat cure moulding, be bonded in the layer of metal foil that scribbles silane coupling agent or there is no silane coupling agent, form composite sheet;
(3) cutting process: the composite sheet in above-mentioned steps cut apart or be die-cut into the cylinder that comprises that the diameter of hydrophobic rubber layer and layer of metal foil is 2-10mm, or the composite sheet in above-mentioned steps cut apart or be die-cut into cross section for ellipse, polygon, cross, star or crescent or their object of combination in any; With alkaline cleaning fluid, clean approximately 5 minutes, washing, then uses 5% hydrochloric acid cleaning 3 minutes, then with deionized water, cleans up, and drains;
(4) preparation of refractory metal alloy coating: by above-mentioned cylinder or object, be immersed in the chemical plating fluid of other refractory metal compound that contains soluble tungsten compound and solubility, stir, by the method for chemical plating, in the metal surface of cylinder or object, form refractory metal alloy coating; Or, above-mentioned cylinder is put into the cylinder of the chemical plating fluid of other refractory metal compound that contains soluble tungsten compound and solubility, allow cylinder rotate, by the method for chemical plating, in the metal surface of cylinder or object, form refractory metal alloy coating;
The tungsten that contains the solubility of 20-150g/L in plating solution, rhenium, osmium, tantalum, molybdenum, niobium, hafnium, vanadium, the compound of chromium or zirconium or the combination in any of these compounds, the transition metal iron of the solubility of 0-60g/L, nickel, cobalt, the compound of copper or manganese or the combination in any of these compounds, the tin of the solubility of 0-30g/L, antimony, the combination in any of lead or bismuth compound or these compounds, the reducing agent of 20-150g/L, the complexing agent of 30-150g/L, the pH value conditioning agent of 20-100g/L, the stabilizer of 0.1-1g/L, the surfactant of 0.1-2g/L, the brightener of 0-50 g/L or roughness conditioning agent,
Preferably inferior sodium phosphate is the reducing agent in plating solution; While adopting inferior sodium phosphate to be reducing agent, the temperature of refractory metal alloy chemical plating that coating adopts is 60-85 ℃, and the time is 30-300 minute, and the pH value of plating solution is 8.0-10.0;
(5) clean, dry: take out above-mentioned plated body, by distilled water or rinsed with deionized water, drain, cold wind dries up or be placed in the constant temperature oven of 70 ℃ and dry, and obtains the metal faced switch contact that is coated with refractory metal alloy.
7. the preparation method of the switch contact containing refractory metal alloy coating according to claim 6, is characterized in that: as preferably, the described time containing refractory metal alloy chemical plating that coating adopts is 100-200 minute; The temperature of plating solution is 70-80 ℃; The pH value of plating solution is 8.5-9.0; In plating solution, contain the strong base-weak acid salt with pH buffer capacity; Described pH adjusting agent is one or more in NaOH, potassium hydroxide, sodium carbonate, sodium acetate, ammoniacal liquor, sodium pyrophosphate, potassium pyrophosphate, preferentially uses ammoniacal liquor or sodium hydroxide solution to regulate the pH value of plating solution.
8. the preparation method of the switch contact containing refractory metal alloy coating according to claim 6, it is characterized in that: described stabilizer is KI, Potassiumiodate, benzotriazole, 4,5-bis-sulfo-octane-1, the mixture of one or more in 8-disulfonate, 3-sulfydryl-1-propane sulfonic acid salt, sodium thiosulfate, thiocarbamide, is preferably sodium thiosulfate, thiocarbamide or both mixtures.
9. the preparation method of the switch contact containing refractory metal alloy coating according to claim 6, it is characterized in that: in the plating solution that described chemical plating adopts, contain one or more in reducing agent inferior sodium phosphate, sodium borohydride, alkylamine borine, hydrazine or titanium trichloride, preferentially select the inferior sodium phosphate that price is low.
10. the preparation method of the switch contact containing refractory metal alloy coating according to claim 6, it is characterized in that: described brightener or roughness conditioning agent are formaldehyde, acetaldehyde, cumal, chlorobenzaldehyde, betanaphthol, 2-methyl aldehyde anil, benzylideneacetone, benzophenone, peregal, western Buddhist alkali, butynediols, propilolic alcohol, 1-diethylin third-2-alkynes, ethoxyquin propilolic alcohol, saccharin, benzoic sulfimide sodium, sodium vinyl sulfonate, propine sodium sulfonate, pyridine-2-hydroxy-propanesulfonic acid inner salt, one or more in APES or commercially available commercial chemical plating brightener.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410346547.7A CN104112608B (en) | 2014-07-21 | 2014-07-21 | A kind of switch contact containing refractory metal alloy coating and preparation method thereof |
| PCT/CN2015/084169 WO2016011913A1 (en) | 2014-07-21 | 2015-07-15 | Switch contact with refractory metal alloy plating and preparation method for same |
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| CN201410346547.7A CN104112608B (en) | 2014-07-21 | 2014-07-21 | A kind of switch contact containing refractory metal alloy coating and preparation method thereof |
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| CN104112608A true CN104112608A (en) | 2014-10-22 |
| CN104112608B CN104112608B (en) | 2016-09-14 |
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| CN201410346547.7A Active CN104112608B (en) | 2014-07-21 | 2014-07-21 | A kind of switch contact containing refractory metal alloy coating and preparation method thereof |
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| CN (1) | CN104112608B (en) |
| WO (1) | WO2016011913A1 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104561959A (en) * | 2015-01-14 | 2015-04-29 | 江苏兴达钢帘线股份有限公司 | Accelerator for promoting formation of chemically tinned bronze alloy coat |
| CN104979125A (en) * | 2014-12-04 | 2015-10-14 | 国家电网公司 | Switch disconnector with metal rubber and power equipment manufactured from same |
| WO2016011913A1 (en) * | 2014-07-21 | 2016-01-28 | 南通万德科技有限公司 | Switch contact with refractory metal alloy plating and preparation method for same |
| CN105463235A (en) * | 2015-12-23 | 2016-04-06 | 四川飞龙电子材料有限公司 | Preparation method for silver-iron-rhenium electric contact material |
| CN108950610A (en) * | 2018-08-27 | 2018-12-07 | 重庆立道新材料科技有限公司 | A kind of trivalent chromium chrome plating layer brightening agent and its plating chromium plating bath |
| CN110541150A (en) * | 2019-08-22 | 2019-12-06 | 沈阳科友真空技术有限公司 | Multilayer film structure for reed switch relay contact and preparation method thereof |
| CN113122830A (en) * | 2021-04-25 | 2021-07-16 | 哈尔滨科友半导体产业装备与技术研究院有限公司 | Tungsten sheet or tungsten crucible surface tantalum coating layer and preparation method thereof |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111020540B (en) * | 2019-12-05 | 2022-04-01 | 光山白鲨针布有限公司 | Medium-phosphorus chemical nickel plating solution and application |
| CN115116742B (en) * | 2022-08-23 | 2022-11-29 | 苏州聚生精密冲件有限公司 | Capacitor manufacturing process for controlling capacitance resistance and soldering-free tin-copper conducting strip |
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| US20030054633A1 (en) * | 1998-07-31 | 2003-03-20 | Industrial Technology Research Institute | Method of electroless plating copper on nitride barrier |
| CN101522954A (en) * | 2006-05-24 | 2009-09-02 | 埃托特克德国有限公司 | Metal plating composition and method for the deposition of copper-zinc-tin suitable for manufacturing thin film solar cell |
| CN101809695A (en) * | 2007-09-26 | 2010-08-18 | 古河电气工业株式会社 | Silver-clad composite material for movable contacts and process for production thereof |
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| JP2012107263A (en) * | 2010-11-15 | 2012-06-07 | Kyowa Densen Kk | Plating structure and coating method |
| CN104112608B (en) * | 2014-07-21 | 2016-09-14 | 南通万德科技有限公司 | A kind of switch contact containing refractory metal alloy coating and preparation method thereof |
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2014
- 2014-07-21 CN CN201410346547.7A patent/CN104112608B/en active Active
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2015
- 2015-07-15 WO PCT/CN2015/084169 patent/WO2016011913A1/en active Application Filing
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| US20030054633A1 (en) * | 1998-07-31 | 2003-03-20 | Industrial Technology Research Institute | Method of electroless plating copper on nitride barrier |
| CN101522954A (en) * | 2006-05-24 | 2009-09-02 | 埃托特克德国有限公司 | Metal plating composition and method for the deposition of copper-zinc-tin suitable for manufacturing thin film solar cell |
| CN101809695A (en) * | 2007-09-26 | 2010-08-18 | 古河电气工业株式会社 | Silver-clad composite material for movable contacts and process for production thereof |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2016011913A1 (en) * | 2014-07-21 | 2016-01-28 | 南通万德科技有限公司 | Switch contact with refractory metal alloy plating and preparation method for same |
| CN104979125A (en) * | 2014-12-04 | 2015-10-14 | 国家电网公司 | Switch disconnector with metal rubber and power equipment manufactured from same |
| CN104561959A (en) * | 2015-01-14 | 2015-04-29 | 江苏兴达钢帘线股份有限公司 | Accelerator for promoting formation of chemically tinned bronze alloy coat |
| CN105463235A (en) * | 2015-12-23 | 2016-04-06 | 四川飞龙电子材料有限公司 | Preparation method for silver-iron-rhenium electric contact material |
| CN108950610A (en) * | 2018-08-27 | 2018-12-07 | 重庆立道新材料科技有限公司 | A kind of trivalent chromium chrome plating layer brightening agent and its plating chromium plating bath |
| CN110541150A (en) * | 2019-08-22 | 2019-12-06 | 沈阳科友真空技术有限公司 | Multilayer film structure for reed switch relay contact and preparation method thereof |
| CN110541150B (en) * | 2019-08-22 | 2024-05-03 | 沈阳科友真空技术有限公司 | Multilayer film structure for reed switch relay contact and preparation method thereof |
| CN113122830A (en) * | 2021-04-25 | 2021-07-16 | 哈尔滨科友半导体产业装备与技术研究院有限公司 | Tungsten sheet or tungsten crucible surface tantalum coating layer and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104112608B (en) | 2016-09-14 |
| WO2016011913A1 (en) | 2016-01-28 |
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