Background technology
Cold-cathode fluorescence lamp is because easily miniaturization, low in energy consumption, characteristic is usually used in recent years liquid crystal panel such as the life-span is long backlight etc.Cold-cathode fluorescence lamp generally has following structure: in the relative pair of electrodes that disposes in inside of the glass tube of having filled rare gas such as argon and mercuryvapour, and connected lead on each electrode.Electrode is shaped as cup-shaped, and be configured to the cup peristome toward each other.By lead after applying voltage between electrode, thereby discharge electronics and produce ultraviolet ray from an electrode with mercury atom collision.Ultraviolet ray is converted to visible rays by the fluorescent film that is formed at the glass tube surface, and sends this visible rays from the inside of glass tube.Therefore, the life-span of cold-cathode fluorescence lamp depends on the consumption of mercuryvapour to a great extent.
Usually make electrode with nickel, in the following example shown in: nickel 99.7%, manganese 0.1%, iron 0.1%, other impurity (carbon, silicon, copper, sulphur) 0.1%.The cobalt that in nickel, comprises the trace about 0.01%.Above mixed proportion is a percentage by weight.After nickel was subjected to the impact of argon gas body of glass tube inside etc., nickle atom was hit away and is dispersed.This phenomenon is called sputter.The nickle atom that disperses obtains mercury vapour and becomes mercury alloy, and the effective dose of mercuryvapour reduces thus.Consequently mercury vapour is consumed and causes the life-span of cold-cathode fluorescence lamp to be reduced.
Therefore, studying the technology that adopts the good electrode of anti-sputtering performance to prolong the life-span of cold-cathode fluorescence lamp in recent years.Specifically, following technology being disclosed: uses and to compare molybdenum that work content is low and anti-sputtering performance is good (Mo) or niobium (Nb) with nickel and wait and make cup-shaped electrode.For example, can open 2002-358992 communique and Te Kai 2003-187740 communique with reference to the Japanese documentation spy.
But, use the cold-cathode fluorescence lamp of these metals to have following problem.The first, there is the problem of surface oxidation in the electrode of refractory metals such as use molybdenum or niobium when being enclosed glass tube.Specifically, in the manufacturing process of cold-cathode fluorescence lamp, electrode is configured in the end of glass tube after, in air, use the seal glass (bead) of baking glass tube one side end such as gas burner thus and it is welded in carry out gas-tight seal on the glass tube.But the heat when making the bead fusion can reach electrode, and electrode surface is oxidized owing to be heated.To cause anti-sputtering performance to reduce after the electrode surface oxidation, therefore can not bring into play rare anti-sputtering performance.And,, reduce so in follow-up operation, be difficult in the atmosphere such as hydrogen because molybdenum or niobium just are difficult to reduction after in a single day oxidized.
The second, because molybdenum or niobium are refractory metals, so the heating of high temperature just can't not obtain enough bond strengths not carrying out very on electrode the time wire bonds.Particularly, because the fusing point of molybdenum is approximately 3400 ℃, and this fusing point than the Kovar alloy through being commonly used for lead (being approximately 1550 ℃) is high a lot, and the fusing lead is bonded on the electrode it so need fully.But, owing to the electrode of molybdenum melts hardly, so the result can't obtain enough bond strengths.In addition, if be heated to the temperature that the electrode of molybdenum fully melts, then lead to high temperature, is become difficult thereby cause engaging by superheated.And, when using the lead of the dual structure of having filled copper in the inside of the outer tube of Kovar alloy system, because the fusing point of copper is lower, be approximately 1080 ℃, so the problem that exists inner copper at first to melt and when welding, flow out.When using cold-cathode fluorescence lamp, copper is used as heat dissipation so that the heat that electrode sends is dispersed into the outside of glass tube.But,, will produce the hollow sectors that does not have copper to fill in the inside of the outer tube of Kovar alloy system, thereby cause heat dispersion to reduce if copper flows out.
The 3rd, molybdenum or niobium price general charged are higher, are that the electrode of basis material is often than the cost height of the electrode of nickel system with these metals.
Summary of the invention
The objective of the invention is to, in view of above problem provides a kind of anti-sputtering performance and makes function admirable and economic cold-cathode fluorescence lamp.
Cold-cathode fluorescence lamp of the present invention has: glass tube, and it is enclosed in the inner space of gas-tight seal at least rare gas and mercury vapour, and is formed with fluorescence coating on inner wall surface; A pair of cylindrical electrode, it is configured in the inner space, and the one end is formed with bottom surface sections, and the other end is formed with peristome, and is configured to peristome toward each other; And lead, the one end engages with bottom surface sections, and the other end is led to the outside of glass tube.Cylindrical electrode is by being basis material with nickel or nickel alloy and having added the material that metal with deoxidation forms and form.
Being added to nickel or nickel alloy is that these metals in the material of base material have and obtain oxygen easily from the outside and with the form of the oxide character at cyrystal boundary segregation.Because the crystal boundary that sputter is tended to optionally a little less than the adhesion between the particle takes place, so by the combination between the particle of being strengthened crystal boundary by these metal oxides, can improve anti-sputtering performance.In addition, because cold-cathode fluorescence lamp of the present invention is basis material with low-melting nickel or nickel alloy also, thus the heating can carry out at low temperatures engaging the time with lead, thus the making performance improved.And, in cold-cathode fluorescence lamp of the present invention,,, and can effectively suppress material cost so processing characteristics is good because cylindrical electrode is a basis material with nickel or nickel alloy.
The preferred titanium of metal with deoxidation, preferred 0.01~2.0 percentage by weight of the mixed proportion of titanium.
Metal with deoxidation also can be a zirconium, preferred 0.05~1.1 percentage by weight of the mixed proportion of zirconium.
Metal with deoxidation also can be a hafnium, preferred 0.05~1.1 percentage by weight of the mixed proportion of hafnium.
Lead also can have with electric conductor and forms peripheral part and filled the double-layer structural of copper or copper alloy in inside.
Electrode of the present invention is the cylindrical electrode that is used for cold-cathode fluorescence lamp, and the one end has bottom surface sections, and the other end has peristome, and by being basis material with nickel or nickel alloy and having added the material that metal with deoxidation forms and form.
Electrode unit of the present invention has the lead that above-mentioned electrode and an end engage with the bottom surface sections of electrode.
Lead also can have with electric conductor and forms peripheral part and filled the double-layer structural of copper or copper alloy in inside.
As mentioned above, because the material that cold-cathode fluorescence lamp of the present invention has the adhesion of the crystal boundary that has improved nickel, so can realize the anti-sputtering performance more superior than existing nickel material.In addition, it is also very good to make performance and economic performance, can fully reach purpose of the present invention.
Above-mentioned and other purpose of the present invention, feature and advantage from the following description of carrying out with reference to signal accompanying drawing of the present invention as can be known.
Embodiment
Below, describe first execution mode of cold-cathode fluorescence lamp of the present invention in detail with reference to accompanying drawing.Cold-cathode fluorescence lamp of the present invention is suitable as the backlight of liquid crystal panel, also can be applied to the cold-cathode fluorescence lamp of other purposes.Fig. 1 is the sectional view of concise and to the point structure that first execution mode of cold-cathode fluorescence lamp of the present invention is shown.
Cold-cathode fluorescence lamp 1 constitutes by the two ends of the glass tube 2 that formed by pyrex with seal glass (bead 3) gas-tight seal.The external diameter of glass tube 2 is in the scope of 1.5~6.0mm, preferably in the scope of 1.5~5.0mm.The material of glass tube 2 also can be lead glass, soda-lime glass, low lead crystal glass etc.
On the inner wall surface 4 of glass tube 2, be provided with not shown fluorescence coating, almost be covered with the total length of inner wall surface 4.The fluorophor that constitutes fluorescence coating can suitably be selected from existing or new fluorophor such as halogen-phosphate fluorophor or rare earths fluorophor according to the purpose and the purposes of cold-cathode fluorescence lamp 1.And the fluorophor that fluorescence coating also can be mixed by two or more fluorophor constitutes.
In by the inner space 5 of inner wall surface 4 cingens glass tubes 2, enclose the rare gas and the mercury such as argon, xenon, neon of scheduled volume, and its internal pressure is decompressed to atmospheric about 1/tens.
Two ends at the length direction of glass tube 2 are provided with pair of electrodes unit 6.Each electrode unit 6 is made of cylindrical electrode 7 and the lead 9 that engages with the bottom surface sections 8 of cylindrical electrode 7.The cylindrical electrode 7 of each electrode unit 6 is configured in the inner space 5 of glass tube 2 end than length direction a little near on the inboard position, and makes between the peristome 10 of peristome 10 and other electrode unit 6 of this cylindrical electrode 7 relative.One end of each lead 9 is welded on the bottom surface sections 8 of corresponding cylindrical electrode 7.The other end runs through bead 3 and is led to the outside of glass tube 2.Electric conducting materials such as lead 9 usefulness Kovar alloies are made.
Fig. 2 is the amplification stereogram of the electrode unit 6 that has of cold-cathode fluorescence lamp 1.The cylindrical electrode 7 that constitutes electrode unit 6 has cylindrical portion 23, and a side of the length direction of this cylindrical portion 23 is as peristome 10 and opening, and opposite side seals by bottom surface sections 8.Cylindrical electrode 7 is shaped by metallic plate being struck out cylindrical (cup-shaped).The end face 12 of lead 9 one sides is welded in the bottom surface sections 8 of cylindrical electrode 7.
Cylindrical electrode 7 forms by following material, that is: this material is a basis material with nickel or nickel alloy, and adds the metal (hereinafter referred to as additive) with deoxidation.As additive, can list titanium, zirconium, hafnium.Preferred 0.01~2.0 percentage by weight of the mixed proportion of titanium, preferred 0.05~1.1 percentage by weight of the mixed proportion of zirconium, preferred 0.05~1.1 percentage by weight of the mixed proportion of hafnium.The upper limit of each mixed proportion mainly depends on the making performance of cylindrical electrode 7.That is, if the above mixed proportion of the upper limit, thereby then material hardens to be difficult to drawing be cylindrical shape.The lower limit of each mixed proportion is set according to obtaining enough anti-sputtering performance, will describe in detail in the back.
An embodiment consists of: nickel 99.7%, titanium 0.05%, manganese 0.15%, other impurity (carbon, silicon, copper, sulphur, magnesium, iron) 0.1%.In addition, the cobalt that comprises the trace about 0.01% in the nickel.
Illustrate by mixing these metals with reference to Fig. 3 and to improve the reason of the anti-sputtering performance of cylindrical electrode 7.Below, be that example illustrates with the titanium, also be the same for zirconium, hafnium.Nickel or nickel alloy are generally the polycrystalline structure, and form crystal boundary B on the interface of crystallization G.Crystal boundary B is because a little less than the interparticle connection, so be subjected to the influence of sputter easily.Sputter mainly takes place and gradually to the internal extended of crystallization G from crystal boundary B.Even molybdenum or niobium, oxidized after, sputter also can obviously advance from crystal boundary B.As previously mentioned, just be difficult to reduction after these materials are in a single day oxidized, therefore be difficult to recover anti-sputtering performance.
To this, the present invention has utilized the deoxidation characteristic of titanium.That is, the additive in the nickel tends to the segregation at crystal boundary B, and titanium is no exception.Therefore, by making titanium in the abundant segregation of crystal boundary B and obtain oxygen, can improve the adhesion between the crystallization of crystal boundary B, thereby improve the anti-sputtering performance of electrode from the outside.The minimum value of above-mentioned mixed proportion is to make the titanium of q.s be distributed in the needed amount of crystal boundary B in order to improve anti-sputtering performance.
Here, what have improved, made sample and confirm its sputtering performance in order to check anti-sputtering performance.In test, in nickel, add titanium, zirconium, hafnium respectively, and make the different a plurality of samples of addition (percentage by weight), thereby estimate anti-sputtering performance and processing characteristics.Evaluation be with pure nickel relatively, by good to poor order be 1,2,3,4.Because the anti-sputtering performance of pure nickel is not fine, institute thinks 3, because processing characteristics is good, institute thinks 1.Anti-sputtering performance judges that by the sputter amount of range estimation electrode the sputter amount is 1,2,3 by few order at the most.The precision of the shape of the forming characteristic of processing characteristics by taking all factors into consideration cup-shaped electrode, shaping, have zero defect to wait to judge, by good to poor order be 1,2,3,4.4 of processing characteristics just is unsuitable for the state of the processing characteristics of practical level, is qualified below 3.In addition, anti-sputter is that 3 sample is compared with pure nickel and do not had advantage, so do not adopt.So carry out the evaluation of each sample, and obtained result as shown in table 1.The sample that anti-sputtering performance and processing characteristics are taken into account is No2~5,8,11,12 (using shadow representation in the table).Like this, the anti-sputtering performance of having confirmed to add the electrode of additives such as titanium, zirconium, hafnium in nickel has had significant raising than (not having additive) electrode of existing nickel system.The anti-sputtering performance and the processing characteristics of sample of titanium of particularly having added 0.05 percentage by weight is all very good.
<table 1 〉
Sample | Additive and composition (percentage by weight) | Characteristic |
No | Titanium | Zirconium | Hafnium | Anti-sputtering performance | Processing characteristics |
Matrix | (pure nickel) | 3 | 1 |
1 | 0.005 | | | 3 | 1 |
2 | 0.01 | | | 2 | 1 |
3 | 0.05 | | | 1 | 1 |
4 | 0.5 | | | 1 | 2 |
5 | 1.55 | | | 2 | 3 |
6 | 2.1 | | | | 4 |
7 | | 0.01 | | 3 | 2 |
8 | | 0.6 | | 2 | 3 |
9 | | 1.3 | | | 4 |
10 | | | 0.02 | 3 | 1 |
11 | | | 0.31 | 2 | 2 |
12 | | | 0.66 | 1 | 3 |
13 | | | 1.4 | | 4 |
Cold-cathode fluorescence lamp of the present invention has not only improved anti-sputtering performance, can also improve the making performance.Cylindrical electrode 7 is owing to the mixed proportion that with nickel or nickel alloy is basis material and additive is little, so the fusing point of fusing point and nickel (1455 ℃) is basic identical.Because the fusing point (1550 ℃) of the fusing point of cylindrical electrode 7 and the material Kovar alloy of lead 9 is basic identical, so when lead 9 being welded and is fixed on the cylindrical electrode 7, soften to both equal extent and merge mutually, thereby form alloy-layer betwixt and firmly fixed.Relative therewith, when constituting electrode, lead 9 fusings are fixed by high-melting point metal such as molybdenum or niobiums, therefore be restricted easily at aspects such as bond strength and joint sequencies.The present invention can address these problems simultaneously.And, because the mixed proportion of the additive of cold-cathode fluorescence lamp of the present invention is little, so the influence to cost can be suppressed to minimum degree.That is,,, therefore can provide economic cold-cathode fluorescence lamp so the electrode of cost and nickel or nickel alloy is more or less the same because the major part of cold-cathode fluorescence lamp of the present invention is made by nickel or nickel alloy.
Second execution mode of cold-cathode fluorescence lamp of the present invention then, is described.The cold-cathode fluorescence lamp of present embodiment is different with the structure of the conduit of first execution mode, and other parts are identical with first execution mode.Therefore, only the structure to conduit describes, and omits the explanation of the component part identical with first execution mode.
As shown in Figure 4, the lead 9b of formation electrode unit 6b has following multi-ply construction (double-layer structural): insert the inside part 32 that is made of copper (Cu) or copper alloy in the inside of the Outboard Sections 33 that is made of Kovar alloy.Inside part 32 is provided with in order to distribute the heat that produces from electrode.The head portion of multi-ply construction part combines with the Dumet copper-clad iron-nickel alloy wire 34 that covers the dilval periphery with copper, and is connected with supply unit (not shown) by Dumet copper-clad iron-nickel alloy wire 34.
Identical with first execution mode, cylindrical electrode 7 is formed by following material, and this material is to be basis material with nickel or nickel alloy, and has added the metal that titanium, zirconium, hafnium etc. have deoxidation in this basis material.Therefore, identical with first execution mode aspect anti-sputtering performance.In addition, the fusing point of cylindrical electrode 7 and the fusing point of nickel are roughly the same, thus when wire bonds 9b, do not need too high temperature, thus therefore reduced because the heat during welding makes the inside part 32 overheated possibilities that cause copper to flow out to the outside of lead 9b.Therefore can fully guarantee the heat dispersion of lead 9b.
Abovely describe the present invention, but the present invention is not limited to above-mentioned execution mode certainly, but various distortion can be arranged according to execution mode.For example, enumerated titanium, zirconium, hafnium, but also multiple above metallic combination can have been got up use as additive.
In addition, by the position of sputter be the part of bottom surface sections 8 one sides of the cylindrical portion 23 of cylindrical electrode easily.Therefore, also can also can improve the mixed proportion of the metal with deoxidation of this part only at this partially mixed metal with deoxidation.
More than preferred implementation of the present invention has been carried out prompting and detailed explanation, but only should be understood to otherwise the purport or the scope of disengaging claim just can be carried out various changes or correction.