KR200452994Y1 - Flexible multi-layered getter - Google Patents

Abstract

Flexible multi-layer getter having a gas permeable layer comprising a gas storage layer. In an embodiment, the gas-permeable layer comprises some gas reservoir layer. In another embodiment, a barrier includes a gas storage layer, which may comprise a foil substrate, a passivation, or a gas permeable layer.

Description

Flexible Multi-Layer Getter {FLEXIBLE MULTI-LAYERED GETTER}

An exemplary embodiment of the present invention relates to a gas absorption getter, and more particularly to a composite getter. Other exemplary embodiments relate to their production.

In many technically advanced applications, gas absorption is obtained with nonvolatile getter (NEG) materials. NEG materials are often found in two types of applications. In the first type of application, NEG materials are used to purify gas flows by absorbing unnecessary fractions. For example, by using NEG materials in the semiconductor industry, unnecessary fractions such as hydrogen, oxygen, nitrogen, water, carbon oxides and nitrogen oxides can be removed from the noble gas stream. Similarly, the gases used in the manufacture of certain gas filling devices, such as incandescent bulbs, are purified to provide advantages such as, for example, to enhance filament life.

In the second type of application, NEG materials are used to maintain a high degree of vacuum in a sealed enclosure. In the semiconductor industry, processing chambers are a common example of such an enclosure. Such enclosures are found in thermal insulation devices such as thermos, dewars, microelectronic containers and insulated pipes for refinery extraction and refinery transportation in the Arctic and subsea areas, for example. For these applications, the sealed enclosure typically includes the inner and outer walls with an evacuated volume introduced between the inner and outer walls. For refinery extraction and transportation, it is often necessary to use insulated pipes to prevent excess cooling of the fluid. This cooling causes the heavy constituents of the essential oil to solidify and consequently increase their overall viscosity, potentially creating an obstruction.

NEG materials may include zirconium and titanium and alloys based on these metals and compounds thereof. Such alloys may include, for example, one or more other components selected from transition metals and aluminum, and their oxides. NEG materials have been the subject of several patents. U.S. Pat.No. 3,203,901 is a Zr-Al alloy, specifically, with a mass percentage of Zr 84% -Al 16% by weight, produced and sold under the name St 101® by Laesate, SAES Getters SpA, Italy. The alloy to be described is demonstrated. U.S. Patent No. 4,071,335 is a Zr-Ni alloy, specifically, with a mass percentage of Zr 75.7% -Ni 24.3%, produced and sold under the name St 199® by Laesate, SAES Getters SpA, Italy. The alloy to be described is demonstrated. U.S. Patent No. 4,306,887 is a Zr-Fe alloy, specifically, with a mass percentage of Zr 76.6% -Fe 23.4%, produced and sold under the name St 198® by Lainate, SAES Getters SpA, Italy. The alloy to be described is demonstrated. U.S. Pat.No. 4,312,669 describes Zr-V-Fe alloys, specifically alloys produced and sold under the name St 707® with a mass percentage of Zr 70% -V 24.6% -Fe 5.4%. US Pat. No. 4,668,424 describes Zr-Ni-A-M alloys in which A represents at least one rare earth element and M represents at least one element selected from cobalt, copper, iron, aluminum, tin, titanium and silicon. US Pat. No. 5,961,750 describes a Zr-Co-A alloy wherein A is yttrium, lanthanum, rare earth elements and mixtures thereof. This application describes in detail the alloys whose mass% of components is Zr 80.8% -Co 14.2% -A 5%, produced and sold under the name St 787® by Laesate, SAES Getters SpA, Italy. do.

Gas uptake through NEG material appears to occur in two stages. The first step is the surface area chemisorption of gaseous fractions at the NEG material surface and is generally carried out by the separation of its constituent reactors of the fractions. In the second step, the constituent atoms are released into most of the NEG material. In the case of hydrogen absorption, as the hydrogen atoms diffuse in the material, solid solutions are first formed even at low temperatures. As the hydrogen concentration increases, ZrH ₂ Hydrides such as are formed. Hydrogen absorption capacity is high even at low temperatures.

The second step is different for each element such as oxygen, carbon and nitrogen. At relatively low temperatures (depending on the type of NEG material, generally lower than approximately 300-500 ° C.) only surface area chemisorption occurs, and a surface layer of oxide, carbide or nitrogen compound is formed. These layers effectively block the occurrence of mass diffusion. At high temperatures, oxygen, nitrogen and carbon atoms can diffuse into the NEG material, thus regenerating a clean surface for further gas absorption. Therefore, surface cleaning can be obtained continuously by constantly maintaining the NEG material at a sufficiently high temperature. Alternatively, the surface of the NEG material maintained at a low temperature can be cleaned by periodically heating it to a sufficiently high temperature. The latter process is generally known as "activation" treatment and can be performed at regular intervals or when a loss of absorption capacity is found.

However, there are various applications of NEG materials that cannot be heated to enable activation of such materials. Such applications include maintaining high vacuum in closed enclosures such as those found in x-ray tubes, field emission flat panel displays, thermos, dewars, fluorescent lamps and insulated pipes used for oil extraction and refinery transportation. . Another important application of this kind is both rechargeable batteries of Ni-metal hydride batteries and batteries of non-charged batteries such as conventional alkaline batteries. As is well known in the art, batteries include a positive electrode, a negative electrode and an electrolyte distributed therebetween, all contained within a package. Under certain operating conditions, both alkaline and rechargeable batteries can release hydrogen to inflate the packaging and present a risk of explosion. Accumulation of hydrogen may occur in closed containers such as munitions and spark (manufacture) containers. Due to the presence of hydrogen, activating the NEG material by heat can be extremely dangerous.

Absorption of a relatively small amount of oxygen, nitrogen or carbon in the application at such low temperatures creates a passivation layer on the NEG material surface, as described above, prevents further gas absorption and absorption of the NEG material. Reduces the ability to a small fraction of the theoretical value In addition, the passivation layer, as already described, blocks hydrogen absorption, but may otherwise occur at room temperature.

In some applications using NEG materials, the presence of hydrogen can be particularly dangerous. This is because hydrogen is an excellent thermal conductor in thermal insulation applications. Even in trace amounts, the hydrogen in the introduced volume significantly deteriorates its thermal insulation properties. The presence of hydrogen in the gas-filled mixture of lamps alters the discharge conditions, so that both prevent the lamp from functioning best and thus generally shorten its life. In addition, hydrogen is dangerous because if exposed to a flame, it results in rapid oxidation and explosion. This is particularly a concern when the hydrogen gas self-explodes or withdraws gas from components that are combustible.

Formation of getter deposits is possible by, but not limited to, some techniques, including, for example, sputtering, evaporation, and deposition on a support. The sputtering technique deposits films with thicknesses from micrometers (microns, micrometers) to fractions up to approximately tens of microns. The film has excellent adhesion on the substrate by exchange and is resistant to particle loss. With sputtering, it is possible to control the shape of the deposit and make the most of it for the anticipated application. For example, the columnar shape may exhibit a high specific surface area (surface area per unit weight of deposit). In addition, this technique allows for a high level of control over the lateral position of the deposit and ensures the getter deposit is properly aligned. Because of the above advantages of sputtering, this is the preferred technique in many applications. United States Patent Publication. 2004/0253476 describes the formation of a multilayer getter structure.

The getter material is pressed and sintered to form pellets, disks or other useful forms. The powder of material may be deposited onto a substantially planar substrate using techniques such as cold rolling or screen printing. The formation of pellets, the use of containers and cold lamination are well known in the field of powder metallurgy, and details of screen printing techniques applied to getter materials are described in US Pat. No. 5,882,727.

The getter material is typically treated to clean the surface of the getter material that can activate the getter material. Although the getter material has already been chemically activated, it may receive additional thermal activation. Components of the device incorporating the getter at high temperatures are likely to release gas. The activation is usually performed in a pumped down chamber to remove this gas, but in the final step the getter is enclosed inside the apparatus. If the cavity is closed, external pumping will be ineffective. The environment in the device is then controlled by pumping in an inert or non-reactive gas or by maintaining a vacuum. From that point on, the getter is dedicated to withdrawing gas from the constituents into the environment.

The activity of the getter material may not be convenient in cases such as fats and oils. Since the getter is typically thermally activated, the exchange of the getter is a time consuming operation that involves heating to the required temperature before placing the getter material. In practice in all cases, getter materials that do not require activation are more convenient than getter materials that require them.

Getters are usually relatively large and large, and efforts are underway to reduce their size. Still, it is difficult to place some getters in some environment (eg, getter material inside or around dewars). For example, an MRI machine is not viable without retrofitting or redesigning the machine. In some instances, the available getters are either too thick or cannot spread effectively over area. Most of the bulk may be a substrate, often a ceramic.

Many getter materials become particulates over time. It may be undesirable to drop fragments of getter material into the environment for functional or aesthetic reasons. For example, a relatively unsophisticated observer may accept that a device with a particulate getter is broken or of low quality. Particles of material consumed can have a strong impact on the mechanical or electronic functionality of the device.

Many getters produce organic gases (outgas organic) in water or outgoing gases. In some cases, this may be unwanted. Corrosive organic compounds, such as chlorine and fluorine, escape the gas and potentially cause damage.

Getter materials can be expensive. The cost is due to the high cost of the substrate material and / or getter material itself, which is expensive. Moreover, it is typically not possible to cost-effectively reuse the getter material due to the characteristics of the substrate, such as the relative cost of the substrate compared to the getter material and the difficulty in removing the getter material from the substrate. Some getters use relatively expensive materials, such as palladium, which is uneconomical.

The getter material can be difficult to transport due to the fragility of the getter material and substrate, the reactivity of the getter material, or the bulkiness of the getter or the substrate to which the getter is attached.

The getter material can be broken, for example, fragile, brittle, susceptible to degradation through the environment or other contamination. After the getter is used, it will also break. Such brittle properties usually include susceptibility to contamination such as mud, temperature, light, moisture, and other environmental factors.

Getter materials can be difficult or time consuming to produce. For example, getter substrates generally must boil in multiple solvents before applying the getter material. Getter materials should be soldered in the designated spaces to prevent them from moving around. Other getter materials are heavy and difficult to place where desired.

Embodiments of the invention are illustrated in the drawings. However, the embodiments and drawings are illustrative rather than limiting, and provide embodiments of the invention.
1 depicts a peristaltic getter according to an embodiment.
2 depicts a foil substrate according to an embodiment.
3 depicts a three layer getter according to an embodiment.
4 depicts an alternative three layer getter according to an embodiment.
5 depicts a getter tape according to an embodiment.
6 depicts a conceptual diagram of a multilayer getter according to an embodiment.
7-11 depict a flowchart of a method according to an embodiment.
Like reference numerals in the drawings may refer to like components.

In various embodiments, one or more of the problems described above are reduced or eliminated.

The multi-layer getter according to the embodiment of the present invention can be used for various application techniques. By way of example, and not by way of limitation, multi-layer getters can be used in closed vessels with items that eliminate hydrogen gas. In some cases, the item may be adversely affected by water, and advantageously, in one embodiment, the multilayer getter also removes the outgased hydrogen without water byproduct. In some cases, it may be desirable to exchange or apply the multi-layer getters in this field. Advantageously, the embodiment may not require activation.

The above proven use of a multilayer getter is just one non-limiting embodiment, whereby the multilayer getter is substantially a parameter that substantially meets at least approximately through any of several embodiments. It can also be used in gettering applications with).

In accordance with an exemplary embodiment, FIG. 1 depicts a flexible getter 100 (not related to scale). The flexible getter 100 includes a gas permeable layer 102, a gas storage layer 104, and a barrier 106.

In the embodiment of FIG. 1, the gas-permeable layer 102 may be, but is not limited to, a palladium coating of thickness less than about 10 μm, more preferably less than about 5 μm, for example. Increasing the thickness slows the hydrogen absorption rate and increases the consumption of expensive palladium. In an exemplary embodiment, the gas permeable layer is between about 0.5 μm and 2 μm thick. Smaller thicknesses may increase the likelihood of pinhole defects or reduced durability. It will be apparent to those skilled in the art that cost / performance analysis can be performed in a variety of applications.

In an exemplary embodiment, gas permeable layer 102 includes, but is not limited to, metals such as, for example, palladium and compounds of palladium and other materials. Palladium may include the concentration of tin, gold, boron, lead, silver or mixtures thereof by way of example and not by way of limitation. In embodiments, the palladium silver alloy may comprise silver in an atomic ratio of up to about 30%.

Additives to palladium may contribute to increasing the concentration of hydrogen at a given gas pressure and temperature, which may be absorbed by, for example, gas permeable layer 102. Since the additive appears to enlarge the size of the interstitial site in palladium, it can be recognized to increase the solubility of hydrogen. However, the additive is likely to reduce hydrogen solubility as the interstitial site is filled. Advantageously, the gas storage layer 104 can pump hydrogen through the gas permeable layer 102, and the reduced availability of hydrogen may in some embodiments be less relevant.

Materials containing palladium and palladium are not the only materials that could be used. In general, the gas permeable layer 102 according to the embodiment should be catalytic and permeable to the target gas and resistant to obstructions. Some materials may include some or all of these properties. Such materials may include, but are not limited to, iridium, rhodium, ruthenium, titanium, tantalum, platinum, or alloys thereof. Many transition metals, in particular transition metals of Group VIII such as nickel and platinum, naturally absorb hydrogen in the reverse way. In addition, some materials may not generally be catalytic, but the surface may be modified to be catalytic. Such a material can be used for the gas permeable layer 102.

In an exemplary embodiment, absorption of the target gas includes breaking the target gas molecule into atoms or smaller molecules in a catalytic manner. The hydrogen molecule (H ₂ ) may be broken into its constituent atoms before being absorbed by the gas-permeable layer 102. The target gas may be part of a compound or mixture that is first pyrolyzed prior to absorbing the target gas. For example, phosphine (PH ₃ ) gas can be withdrawn using certain munitions. In this case, the target gas may alternatively be called phosphine or hydrogen. In order to absorb hydrogen, the gas permeable layer 102 must first split the phosphine to release hydrogen.

Breaking a molecule into its constituent atoms or smaller molecules is sometimes called dissociation. For example, nautical mile dissociation can be represented by the following general formula: H ₂ ⇔ 2H _{ad ,} where H _ad is hydrogen absorbed. Or in the case of phosphines, PH ₃ ⇔ + 3H _ad . The bidirectional arrow, ⇔, indicates that the reaction may be reversed in embodiments.

In the case of hydrogen, the dissociated hydrogen atoms can be dispersed in a lattice (generally metallic). Hydrogen dispersed in the lattice occupies interstitial sites in the lattice. This phenomenon is demonstrated by neutron diffraction and can be inferred from other sources. Metallic lattices are well known in metallurgical art and therefore do not provide a detailed description of metallic lattices here.

A lattice that allows atoms or molecules of the target gas to exit through the lattice structure may be referred to as being transparent to the target gas. Since the hydrogen atoms are very small, gas permeable layer 102 usually passes through at least hydrogen. Diffusion of dissociated hydrogen atoms can be represented by the following formula: H _ad ⇔ H _M , where H _M represents hydrogen in the metal lattice (eg in the palladium lattice). Gas-permeable layer 102 may be transparent or opaque to other gases besides hydrogen.

Atoms or molecules may occupy the surface of the gas permeable layer 102 or, if the atoms or molecules are small enough, they may occupy deep within the lattice. If an atom or molecule occupies surface sites but does not pass through the inner depth, gas permeable layer 102 would have reduced gettering capability due to interference. This occurs when large atoms or molecules are attached (and 'sticked') to the surface of gas permeable layer 102, but too large to pass through.

Another form of obstruction is corrosive, similar to the obstruction by large atoms or molecules. The resistance of metals to corrosion is dependent on the material. Precious metals such as gold and silver are known to be corrosion resistant, in a number of applicable environments, such as air. Iron, on the other hand, does not have corrosion resistance, especially in air, because of its tendency to oxidize, even though it is alloyed to have corrosion resistance.

Some materials are not particularly resistant to corrosive behaviors, as they make excellent getters. By way of example, and not by way of limitation, titanium has an exceptional gettering capability for hydrogen and can absorb relatively large amounts of hydrogen. However, it is easy to form an oxide surface layer which is oxidized in air and reduces the gettering ability of titanium. Titanium is used, for example, in titanium sublimation pumps. Because titanium sublimation pumps oxidize relatively slowly, they are usually used in a vacuum or oxygen free atmosphere.

In the embodiment of FIG. 1, the gas storage layer 104 is covered by the gas permeable layer 102 and at least slightly protected. The use of the term "covered" in this context refers to the gas permeable layer 102 that substantially coated the surface of the gas storage layer 104. Pinholes do not necessarily substantially degrade the gettering capability of the getter 100, but in embodiments, holes in the gas permeable layer 102 are avoided. Moreover, gas permeable layer 102 may or may not cover the entire surface of gas storage layer 104 or only cover the surface, without covering only the edges of gas storage layer 104.

Gas storage layer 104 may or may not be corrosion resistant. Indeed, any material that would be valuable as a gas storage material, such as titanium, can be oxidized in air. The gas storage layer 104 may comprise, for example, titanium, zirconium, hafnium, niobium, tantalum, vanadium, or yttrium, or transition metals (eg, titanium, zirconium, chromium, manganese, iron, cobalt, nickel, aluminum, copper , Tin, silicon, yttrium, or lanthanum) and alloys thereof, rare earth elements, or mixtures thereof. In addition, compounds of metals and alloys such as metal oxides as well as non-metal getter materials and absorbers may be used. Examples are Ti-V alloy, Zr-V alloy, Zr-Al alloy, Zr-Fe alloy, Zr-Ni alloy, Ti-V-Mn alloy, Zr-Mn-Fe alloy, Zr-V-Fe alloy, Zr -Ni-AM alloys, and Zr-Co-A alloys, where A refers to Y, La, any element of rare earth elements, or mixtures thereof, and M is Co, Cu, Fe, Al, Sn, Refers to Ti, Si, or mixtures thereof.

In the embodiment of FIG. 1, the gas storage layer 104 may be a titanium layer having a thickness of less than about 20 μm, more preferably a titanium layer having a thickness of less than 5 μm, by way of example and not limitation. In an embodiment, the gas storage layer 104 may be about 1 μm to 3 μm thick. The gas storage layer 104 can be made thinner, but the desired amount that can be trapped inside the gas storage layer 104 may or may not have a direct mass relationship. Accordingly, when the gas storage layer 104 is thin, it is difficult to contain a large amount of hydrogen, for example. Conversely, if gas storage layer 104 is thicker than 2 microns, it may contain more hydrogen, for example. Thus, a 0.1 μm thick gas storage layer 104, or a 1 mm thick gas storage layer 104 is possible in other embodiments. The thickness of gas storage layer 104 may vary depending on the getter material and application parameters used.

In an exemplary embodiment, gas storage layer 104 acts as a reservoir of the absorbed target gas (eg, hydrogen). The amount of hydrogen that can be absorbed by a substance is related to Sievert's law relationship for that substance. Since the gas permeable layer 102 does not need to act as a reservoir, the gas permeable layer material need not have a good Sievert's law relationship. However, the gas storage layer 104 must have a relatively high Sievert's law relationship and depends on the amount of gas that needs to be absorbed in a given application.

Sievert's law established how much gas a given substance could contain at a given pressure.

At moderate pressures, for example, the concentration of hydrogen dissolved in a solid metal is described by the following general formula:

c = sp ^1/2, where, c is the concentration of dissolved hydrogen in the hydrogen in equilibrium with the gas phase at a pressure p, s is a parameter of the Sievert. Sievert's law is well known in the material sciences, so a detailed discussion of Sievert's law is omitted.

In various embodiments, the gas permeable layer 102 is disposed in the gas storage layer 104 by a variety of techniques, and by way of non-limiting example, generally chemical vapor deposition (CVD), liquid phase injection (liquid) evaporation or sputtering techniques called phase impregnation, or roll coating, and chemical deposition in the vapor phase. As used herein, roll coating refers to coating a roll of flexible substrate with a getter material.

In an exemplary embodiment, the gas storage layer 104 is a gas so that pumping of the desired gas is substantially free of gaps therebetween in order to facilitate the gas storage layer 104 through the gas permeable layer 102. Can be adhered to the permeable layer 102. As long as there is any gap between the layers, generally good adhesion will result in enhanced gettering capability. This is because the pumping action can be constant across the gas permeable layer 102 with a pumping force acting perpendicularly to the surface of the gas permeable layer 102 for substantially the entire surface. In some cases, gaps or material deposits may be placed between the gas permeable layer 102 and the gas storage layer 104, and the gas permeable layer 102 has the potential to degrade gettering capability, but has other advantages. Can provide.

In an exemplary embodiment, the gas storage layer 104 may have a parameter of Sievert associated higher than the gas permeable layer 102. Accordingly, by way of example and not by way of limitation, hydrogen atoms dispersed in a gas-permeable layer 102 that is transparent to hydrogen will gather in the gas storage layer 104 past the gas-permeable layer 102 and the system moves for equilibrium. do. In the case of hydrogen, the air has a very low partial pressure of hydrogen. Thus, the getter 100 can be left in the air for a long time before losing its gettering capability. For the purposes of this specification, the getter 100, which has its gettering capability for a long time in air, may be said to be substantially inert in air. In various applications, the "long term" can be measured in hours, days, months, and years.

In an exemplary embodiment, the gas storage layer 104 acts as a reservoir of the desired gas, but is protected by the gas permeable layer 102 from adverse effects from other gases or environmental elements. If the reservoir is full, then the reservoir and the ambient environment will be in equilibrium. However, if the reservoir is not full, then the atoms or molecules of the target gas that will be trapped in the gas permeable layer 102 will be pumped and likely to be trapped inside the reservoir.

Composite material getters using powder grains are described in US Pat. No. 6,682,817 ('817 patent). In the '817 patent, the palladium layer partially covers the powder grains. The '817 patent also describes columnar morphology used to increase the surface area of the getter.

In an exemplary embodiment, the gas storage layer 104 is monolithic. According to an embodiment, the monolith gas storage layer 104 is not referred to as including particles, nor is it referred to as having a circumferential form. This will reduce the likelihood that the particles will run away and handle the material into particulates by use. In an embodiment substantially monolith monolith gas storage layer 104 may be coupled to gas permeable layer 102 with little gap. Since the gas permeable layer 102 includes a monolith gas storage layer 104 and acts as a gas permeable barrier between the gas storage layer 104 and the desired gas, the gas storage layer 104 acquires molecules. There is no need to rely on larger surface areas such as those provided through columnar morphology in order to do so. Gas storage layer 104 may be formed using any of a number of techniques, and by way of non-limiting example, evaporation or sputtering techniques, chemical vapor deposition (CVD), liquid phase impregnation, or roll coating (roll coating).

 The barrier 106 protects the gas storage layer 104 on the opposite side from the gas permeable layer 102. It is understood that the embodiment does not have clearly defined sides, and the barrier 106 may be said to be the protecting parts of the gas storage layer 104 not covered by the gas permeable layer 102. It should be noted. In an embodiment the barrier 106 includes a passivation layer 107. The protective film 107 used here is a layer which reduces the chemical reactivity of the surface. The protective film 107 may include an oxide layer. In an alternative embodiment, the barrier 106 and the protective film 107 are the same one.

In another embodiment, barrier 106 may comprise a flexible substrate, such as a foil (see, eg, FIG. 2). In an embodiment, the protective film 107 may or may not be omitted. For example, if the flexible substrate protects the gas storage layer 104, the protective film 107 does not necessarily have to be formed. In yet another embodiment, barrier 106 may be a gas permeable layer similar or identical to gas permeable layer 102 (see, eg, FIG. 4).

The protective film 107 is well known in the material sciences, indicating that the barrier 106 can be deposited through a controlled protective film on the surface of the gas storage layer 104 opposite the gas permeable layer 102. Except as noted, no specific description is provided herein. Barrier 106 includes, for example, a material of gas storage layer 104 (eg, titanium) that has reacted with oxygen to form an oxide layer (eg, titanium oxide). Preferred barrier materials depend on what the gas storage layer 104 is composed of, but an oxidized barrier will be a suitable barrier for many getter materials.

 If the barrier 106 includes a protective film, such as an oxidized barrier, and then scratch the barrier 106, the scratch may expose the gas storage layer 104 to the circulating atmosphere. As a result, the gettering capability of the gas storage layer 104 may be reduced. Fortunately, barrier 106 is at least partially self-healing in many environments. By way of example, and not limitation, if the gas storage layer 104 is composed of titanium, the surface may be scratched so that the barrier may be rapidly oxidized relative to air.

In an exemplary embodiment, a multi-layer getter comprising a gas permeable layer 102 covering the gas storage layer 104, wherein the gas permeable layer 102 is at least until the gas storage layer 104 is full. It has the additional advantage of not acting as a reservoir. This is because as the target gas flows and passes directly into the gas storage layer 104, the target gas stays in the gas permeable layer 102 for a while. As is known in material science, for example, absorbed hydrogen can change the properties of the getter material, often associated with making the material particulate or having hydrogen at an interstitial site. Stress can cause different changes. The characteristic change of getters that absorb hydrogen is instability.

Advantageously, the gas permeable layer 102 does not suffer a significant drop in hydrogen absorption, for example, because the desired gas stays within the gas permeable layer 102 for a while. Since hydrogen is located in the intrusive position of the gas storage layer 104, the gas permeable layer 102 remains elastic as hydrogen is absorbed by the getter 100. Moreover, since the barrier 106 does not absorb a significant amount of additional gas (or because the barrier 106 is itself gas permeable) in the exemplary embodiment, the barrier 106 retains its elasticity as well. . The gas storage layer 104 does not necessarily reduce the absorption of the desired gas, but if the drop occurs, the gas permeable layer 102 and the barrier 106 provide elasticity and, for example, prominent Particulation ) Can be protected from.

Hydrogen uptake has been shown, for example, to alter certain physical properties of the metal. This changed physical property includes electrical resistance, among others. In many metals, it is believed to originate from electrons associated with hydrogen atoms that inject the s- and d- bands of the host metal, varying the density on the Fermi surface, and reducing the energy band. Cause change. Fermi electrons surrounding hydrogen atoms effectively produce neutral atoms, even if the screening electrons are not in bond.

Since the target gas stays briefly in the gas-permeable layer 102, as previously described, as the target gas is absorbed and stored inside the gas storage layer 104, the effect in the gas-permeable layer 102 is minimal. to be. Even if gas storage layer 104 is full, gas permeable layer 102 will continue to absorb the desired gas. Using this principle, it may be possible to test the properties of the gas permeable layer 102 in determining whether the getter 100 is full. For example, the electrical resistance of gas permeable layer 102 can be measured. If the electrical resistance is higher than the measurement when the gas permeable layer 102 absorbs little or no gas, the gas capacity of the getter 100 is depleted.

Another advantage associated with embodiments of the present invention derives from the fact that the partial pressure of hydrogen in air is not critical. Accordingly, the getter 100 can maintain its gettering capability for a long time in the air. In an environment with hydrogen contamination, the partial pressure of hydrogen will rise and the getter 100 will absorb hydrogen at a faster rate. Thus, in the embodiment, the getter 100 can be made to handle as easily as possible as commercially available aluminum foil (although it is recommended to keep the getter reasonably free from contamination).

Another advantage associated with embodiments of the present invention is that getter 100 can be made without desiccant. Desiccants allow getters to absorb moisture in the air. Therefore, this type of getter must be protected from moisture. By way of example, the getter 100 is free of desiccant. For example, palladium is not a desiccant. Accordingly, if the gas permeable layer 102 comprises, for example, palladium, the getter 100 can be made free of desiccant and resistant to water vapor. This may be an important advantage of extending the life of the getter 100.

Getter 100 has a two-prong approach to the reduction of moisture. First, getter 100 removes hydrogen from the circulating atmosphere and makes it impossible for hydrogen to combine with oxygen to form water. Secondly, the getter 100 prevents the absorbed hydrogen from binding to oxygen after absorption, so that no water is generated as a by-product. Thus, the getter 100 does not produce water as a byproduct.

For example, in the case of an ammunition box containing flares, the flames can drain hydrogen. However, if the getter absorbs hydrogen and then generates water as a by-product, the flames can be lost by moisture. For example, a palladium oxide getter may be associated with the PdO + 2H ⇔ Pd + H ₂ O reaction. In order to remove the water, such getters can be incorporated, for example, in a desiccant mixed with PdO. As previously discussed, desiccants can reduce the lifetime and durability of the product. In addition, there is a water vapor pressure on the desiccant that generally causes corrosion or otherwise adversely affects the ammunition stored in the box. In addition, the desiccant is usually bulky.

By way of example, and not by way of limitation, the water vapor absorbed in Dewar bottles and other super-insulated systems can turn into steam when the system is at room temperature. This creates a source of other gas sources to withstand convection heat losses in the system and creates cryogen losses through vaporization of the steam during system cooling. Advantageously, in an exemplary embodiment, getter 100 does not create such source gas.

The absence of water as a byproduct is equally problematic and can even worsen. For example, hot circulation temperatures result in commercially available getter products that can be toxic to electrical devices or ammunition, allowing gas to escape from organic compounds. In contrast, in the exemplary embodiment, the getter 100 does not allow gas to escape from the organic compound. The getter 100 may be said to be free of by-products because they have harmless by-products.

Getter 100 may be referred to as a multilayer getter foil if the metal components are thin and flexible. For example, in an exemplary embodiment, the gas storage layer 104 may comprise titanium foil. Many metals may be made of thin, flexible leaf or sheet and are described as foils. In general, the foil may be made or folded and not folded into small bundles without substantially impairing the appearance of the foil, or in the case of getters, the gettering capability.

2 depicts a getter 110 with a foil substrate in accordance with an exemplary embodiment. The getter 110 includes a gas permeable layer 112, a gas storage layer 114, and a foil substrate 116. In an exemplary embodiment, gas permeable layer 112 is similar to gas permeable layer 102 (FIG. 1), and gas storage layer 114 is similar to gas storage layer 104 (FIG. 1).

In the embodiment of FIG. 2, the foil substrate 116 is Ultra-High Vaccum (UHV) or vacuum-grade aluminum foil. It has been found that large, thin foil substrates are difficult to RF etch prior to placing a getter material layer on the foil. This is due to RF power reflectivity. In some respects, the foil acts as a large antenna that threatens or acts upon the load changing threat in an RF etching system (or to a sputtering system that reflects excessive energy back to the sputtering object).

Coating system pallets on which the foil substrate 116 and the substrate are located, as a method for removing the cleaning process using expensive, time-consuming, or both, for example solvents, acids, or surfactants. Appropriate electrical contact occurs between the pallets, followed by RF etching. The contact is basically a physical contact which is not immediately noticeable as a solution. The more expensive, rigid materials generally used as substrates usually have intense physical contact with the pallet, since the substrate is generally flat and rigid. Also, when the foil is etched, it changes shape and produces points that lead to or cause catastrophic plasma discharge.

In processes that use expensive, rigid substrates, the RF etch process parameter is the power of the future, or the power injected into the 500 W etch process, and the nominal reflected power is returned to the maximum 4 W circuit. Is applied. SAES Getters USA, Inc. In experiments conducted by the technician, the use of foil caused the reflected power to outperform 80 W before tripping the circuit breaker protecting the power supply. The first reaction by the technician was to place the software at 80 W to protect the equipment. Catastrophic plasma discharge will keep the reflected power as low as 60 W, sometimes concentrating on a point source, and then cut across the foil to melt or otherwise destroy it. Would have done.

Ultimately, a method has been found that allows the technician to reach a reflected power of the nominal range 30-50 W. The method involved increasing physical contact around the edge of the foil. The range allowing the process to proceed without stopping the system was 10-61 W. As an intervening method, in the 50-60 W range, the technician has consistently stabilized the process without overwork, overtime and excessive expenses. This facilitated the fast etching rate. However, the technician has reduced the foil per run as the heat build up inside the system removes the foil and returns the excess reflected power into itself.

In an exemplary embodiment, one method of reducing the reflectance problem is by maintaining strong physical contact around the edge of the foil. Physical contact near the edges is by way of example and not by way of limitation, using Kapton tape, screws and stainless steel weights. Other techniques may be used to ensure sufficient physical contact to allow safe high frequency etching of the foil.

Foils have been found that do not need to be treated with a solvent (eg, isopropanol, methanol, and xylenol) prior to applying the gas bottom layer 114. For example, if the layers 112 and 114 are prepared according to the UHV foil without chemically treating the foil in advance, the gettering capability of the foil is prepared by the getter 110 according to the chemically treated UHV foil. It is assumed to be substantially the same as when used.

Foils have been found that do not need to be pretreated using deposition techniques. In alternative embodiments, it may still be desirable to perform a chemical substrate process or to use a pretreatment technique of evaporation into the foil. In some cases, high frequency etching is an effective technique for pretreated foils. In an exemplary embodiment, high frequency etching is used to remove, for example, organic compounds and oxides in the foil.

Even with satisfactory physical contact, sputtering a first layer of getter material on a foil substrate can be difficult and labor intensive. In an exemplary embodiment, the reflectance problem associated with sputtering is reduced using thermal evaporation.

As is known in the getter production arts, the substrate is generally masked before being treated with getter material. Advantageously, masking is unnecessary in an exemplary embodiment when placed in the gas permeable layer 112 on the high frequency etch, in the gas storage layer 114 or on top of the gas storage layer 114.

In an exemplary embodiment, the gas permeable layer 112 may be disposed above the gas storage layer 114 immediately after the gas storage layer 114 is disposed on the foil substrate 116. In contrast to the prior art, the gas storage layer 114 is monolithic (eg, not cylindrical). The surfaces of the gas permeable layer 112 and the gas storage layer 114 should be as tightly coupled to each other as practical and cost effective.

The thickness of the commercially available getter is generally at least 0.010 ". The foil substrate 116, on the other hand, may be very thin. In another embodiment, the thickness of the getter 110 is thinner than the industrially available getter or Less than 0.010 ". Advantageously, the foil substrate 116 is as thin as an extremely thin metal foil, 0.0075 μm. In an embodiment the getter 110 is about 0.0015 "thick.

In an exemplary embodiment, getter 110 may be used for Dewar disease. When the getter 110 collects inside the dewar bottle, the getter 110 may reduce heat transfer through convection and radiation (via the gettering action) (via shielding through the metal foil substrate 116). Can be. Moreover, in an embodiment the getter 110 can retrofit an existing Dewar bottle design without getter activity and without deformation of the Dewar bottle. In general, these advantages are applicable to applications such as practical containers or thermal insulation devices, but not dewar bottles.

3 depicts a third layer getter 120, by way of example. The getter 120 is a gas permeable layer 122. A transparent layer 124, a gas storage layer 126, and a barrier 128. In one embodiment, gas permeable layer 122 is similar to gas permeable layer 102 (FIG. 1), and in another embodiment, gas storage layer 126 is similar to gas storage layer 104 (FIG. 1). . Barrier 128 includes, but is not limited to, a protective film, a foil substrate, or other flexible substrate.

In the embodiment of FIG. 3, transparent layer 124 is transparent to the desired gas. One reason for inserting the transparent layer 124 between the gas permeable layer 122 and the gas storage layer 126 may be due to cost. For example, the gas permeable layer 122 may be very thin, and the very thin transparent layer 124 inserted between the very thin gas permeable layer 122 and the gas storage layer 126 may be a gas storage layer 126. Could buffer or protect it. Gas permeable layer materials are expensive, and therefore it is speculated that making thin layers results in low cost getters 120.

In an exemplary embodiment, the gas permeable layer 122 includes a expensive material (eg, palladium). If the material is expensive, it may be desirable to minimize the thickness of the gas permeable layer 122. In one embodiment, the gas permeable layer 122 comprising palladium may be only about 1000 angstroms thick. At thicknesses less than 1000 angstroms, it is often difficult to remove pinhole defects, for example, in palladium. However, only one tenth of the palladium requirement is used for 1000 angstroms layers, and the transparent layer 124 can protect the gas storage layer 126.

Similar to the gas permeable layer 102 (FIG. 1), the gas permeable layer 122 preferably has three characteristics: catalytic to the target gas, permeability to the target gas, and resistance to the obstruction. The transparent layer 124, on the other hand, does not require catalytic properties because it has already dissociated until the desired gas reaches the transparent layer 124. In addition, the resistance to the obstruction may or may not be important and may depend on the gas that allows gas permeable layer 122 to pass directly through transparent layer 124. For example, if the gas permeable layer 122 allows only hydrogen to pass directly through the transparent layer 124, then the transparent layer 124 need only be permeable to hydrogen and its resistance to obstructions (eg, oxidation) Has no relationship. Accordingly, the transparent layer 124 will have only one of the features of gas permeable layer-transparency for the target gas described previously.

In a particular example of an embodiment, the gas permeable layer 122 comprises palladium, the transparent layer 124 comprises cobalt, and the gas storage layer 126 comprises titanium. For the purposes of the particular example, the thickness of the gas permeable layer 122 is approximately 1000 angstroms. It should be appreciated that if the palladium layer is thin, the material cost of the gas permeable layer 122 can be significantly reduced. Because cobalt is relatively inexpensive, the total cost of the material can be significantly reduced. For the purposes of the special example, the transparent layer may be about 5 microns in only a few thousand angstroms.

4 depicts an alternative third layer getter 130, according to an exemplary embodiment. The getter 130 may include a first gas permeable layer 132, a gas storage layer 134, and a second gas permeable layer 136. In an embodiment, the first gas permeable layer 132 is similar to the gas permeable layer 102 (FIG. 1), and in other embodiments, the gas storage layer 134 is in combination with the gas storage layer 104 (FIG. 1). similar.

In the embodiment of FIG. 4, the second gas permeable layer 136 is similar to the gas permeable layer 102 (FIG. 1). As shown in FIG. 4, the first gas permeable layer 132 and the second gas permeable layer 136 sandwich the gas storage layer therebetween. This arrangement may be desirable in some cases. For example, if oil spills on the first gas permeable layer 132 (and the first gas permeable layer 132 may be adversely affected by the oil), the second gas permeable layer 136 may be It will still be catalytic and permeable to the target gas. This prevents one side of the getter 130 from breaking the gettering capability.

In order to reduce cost, in an alternative embodiment, an additional transparent layer can be disposed between the first gas permeable layer 132, the second gas permeable layer 136 and the gas storage layer, as described with reference to FIG. 3. In a similar way.

5 depicts a getter tape 140, in accordance with an exemplary embodiment. Getter tape 140 is gas permeable layers 142-1 to 142-N (hereinafter collectively referred to as gas permeable layer 142), gas storage layers 144-1 to 144-N (hereinafter collectively, gas storage layers 144) and tape substrate 146. In an embodiment, gas permeable layer 142 is similar to gas permeable layer 102 (FIG. 1), and in other embodiments, gas storage layer 144 is similar to gas storage layer 104 (FIG. 1). .

In the embodiment of FIG. 5, the tape substrate 146 may include a material that depends on the intended application of the getter tape 140. For example, if the portion of getter tape 140 is tack welded with gold, the tape substrate 146 may be made of gold. In an exemplary embodiment, gas permeable layer 142 and gas storage layer 144 may be divided, leaving gaps 148 between the compartments. In another embodiment, the gas permeable layer 142 and the gas storage layer 144 follow, leaving no gaps 148 between the compartments. In alternative embodiments, the tape substrate 146 may comprise an adhesive.

In an exemplary embodiment, getter tape 140 may be relatively wide and long. For example, the getter tape 140 may have something in common with the substantial width or length of the aluminum foil roll. Since the gas storage layer 144 is protected by the gas permeable layer 142, the getter material must be sufficiently durable to tear off sheets of "field of interest" getter material. For example, a getter on a flexible substrate, such as getter 110 (FIG. 2), is used in a similar manner in accordance with an embodiment.

6 depicts a conceptual diagram of a multilayer getter 150, according to the method of the embodiment. In the embodiment of FIG. 6, the multilayer getter 150 includes a palladium and titanium metal grating. The metal grating is logically divided into a first side 152, a second side 154, a third side 156, and a fourth side 158. The first side 152 comprises a metal lattice comprising palladium, the second side 154 comprises a metal lattice comprising palladium and titanium, and the third side 156 and the fourth side 158 Metal grids including titanium.

In the embodiment of FIG. 6, hydrogen molecules 160 are depicted outside of the metal lattice. Palladium is catalytic to hydrogen molecules, and hydrogen molecules 160 can be broken down into constituent hydrogen atoms 162 and absorbed into the invasive sites of the first side 152 of the metal lattice. Hydrogen absorbed on the first side 152 may be thought of as a wave front of hydrogen concentration. In accordance with the principle of equilibrium, the hydrogen can be dispersed on the first side 152 and fills the nearest sites in the process.

As the hydrogen in the embodiment of FIG. 6 disperses, if the first side 152 was a closed system, even though the hydrogen dispersed on the first side 152 eventually reached equilibrium, the hydrogen eventually reached the second. Reach face 154. The invasive site of the second side 154, which includes both palladium and titanium, is somewhat "larger" than the invasive site of palladium alone. The larger second indented seat 154 attracts more hydrogen. Accordingly, hydrogen atoms reaching the second side 152 have an increased likelihood that the first side 152 will pass to the second side 154.

The increased attraction of the increased invasive sites of the second side 154 makes it unlikely that the hydrogen atoms 164 of the second side 154 will pass through the first side 152 again, Upon entering the second side 154 they proceed again, in accordance with the principle of equilibrium, and disperse inside the second side 154.

Finally, as the hydrogen atom 164 disperses on the second side 154, the hydrogen atom 164 reaches the third side 156. The interstitial site of the third surface 156 further attracts the hydrogen atom 164. Accordingly, hydrogen has an increased likelihood of passing from the second face 154 to the third face 156. As the hydrogen atoms 166 disperse to reach an equilibrium in the metal lattice of the third face 156, there is little possibility of passing through the second face 154 again.

Fourth side 158 is a barrier to hydrogen atoms 166. In the embodiment of FIG. 6, the fourth side 158 includes titanium oxide (conceptually represented by oxygen atom 168 trapped inside the indentation site of titanium). The fourth side 158 can be thought of as a passivation layer or an oxide layer. In alternative embodiments, the fourth side 158 may be replaced with another barrier, such as a foil substrate. The fourth side 158 prevents hydrogen atoms 166 from leaking out of the third side 165 (and the hydrogen is unlikely to pass through the first side and the second side), and the third side 165 ) Effectively confines the hydrogen atom 166.

It should be noted that the first, second and third sides can be thought of as having two layers (the first layer comprises palladium and the second layer comprises titanium). Although in practice, for example, a perfect split between palladium and titanium is exceptionally unlikely, a second layer may not be present.

It should be appreciated that FIG. 6 is not a realistic depiction of the metal grid. The grid, which is somewhat difficult to represent on the ground, is a three-dimensional structure. However, such metal gratings are well known in metallurgy, whereby practical depictions of metal gratings are omitted.

How to use a flexible getter

In the above-mentioned embodiment with reference to FIGS. 1-6, the flexible getter can be used in a number of ways. 7-11 depict a flow diagram of a method according to an embodiment.

7 depicts a flowchart 170 of a method of deploying a flexible getter by the method of the embodiment. In an embodiment, the workflow 170 begins at module 172 where the flexible getter is packaged for transportation. The gas permeable layer of the flexible getter may make a relatively elastic flexible getter. When transporting the getter, it is also desirable to take some precautions.

For example, it is preferable to shrink wrap or vacuum wrap the flexible getter. Vacuum packaging is well known. Advantageously, however, the flexible getter may be manufactured as a roll (much like commercially available aluminum foil). The entire roll may be vacuum packed prior to shipping. Alternatively, by way of example and not by way of limitation, the flexible getter may be packaged in sheets or pneumatic containers that are shrink shrink wrapped.

Unlike typical commercially available getters, the flexible getters withstand adverse environmental conditions. Thus, even if the package is punctured in transit, the flexible getter is reasonably usable upon receipt.

In another embodiment, workflow 170 leads to module 174 from which the flexible getter is removed from the package, allowing the flexible getter to self-activate. This is done by humans or robots. Because the flexible getters are relatively elastic, no special steps are needed to protect them, and ordinary environments (including oxygen, dust, water, etc.) usually adversely affect the performance of the getters. Will not give. However, it is desirable to avoid contaminating the surface of the flexible getter. Therefore, the technician must wear gloves and make sure that the working environment is relatively free of contaminants such as vehicle fuel or lubricants.

Advantageously, in an exemplary embodiment, the flexible getter may be used immediately after receipt. This is due to the fact that flexible getters do not require chemical or thermal activation. As soon as a package that can be a vacuum package is disclosed, the flexible getter can be deployed. This may be called the "self-activating function" of the flexible getter.

In an exemplary embodiment, workflow 170 continues with module 176 where the flexible getter is located. Advantageously, in an exemplary embodiment, the flexible getter is relatively thin. In a particular embodiment, the flexible getter is as thin as commercially available aluminum foil. The thickness of the flexible getter facilitates placement in multiple discrete spaces that are minimal. The flexible getter can be used, for example, as a sheet or scrunched up to the corner of the container.

8 depicts a workflow diagram 180 of a method of applying a flexible getter in a working environment, according to an exemplary embodiment. In an embodiment, workflow 180 begins with module 182 positioned so that a roll of the flexible getter is accessible.

Advantageously, in an embodiment, the flexible getter is not adversely affected by the general working environment. Accordingly, the flexible getter is by way of example, and not limitation, attached to a wall or workbench without special protective measures. It is the long term gettering capability that the roll of the flexible getter must maintain under normal circumstances.

In an embodiment, workflow 180 continues at module 184 where the sheet of flexible getter is pulled away from the roll. Since the flexible getter can be placed at a convenient location in the working environment, the technician is only required to peel off the sheet if necessary. In an exemplary embodiment, activation is not required, allowing the technician to save a considerable amount of time.

In an embodiment, workflow 180 continues at module 186 where the sheet of flexible getter is located. Once the flexible getter is positioned, other advantages are evident. For example, the flexible getter produces water or organic pollutants. This is a particular advantage in the application technology in that moisture can cause damage to components and organic contaminants and can corrode components or containers. Accordingly, the flexible getter may be valuable as a periodic getter exchange of an annual exchange, such as an ammo box or a duo bottle.

9 depicts a workflow diagram 190 of a method of recycling getter material, by way of example implementation. In an embodiment, the workflow 190 begins at module 192 where the multi-layer getter foil is located in the bin. It will be appreciated that workflow 190 is for the purpose of recycling multi-layer getter foils. However, since the steps associated with removing the foil substrate can be avoided, it may be easier to apply to a getter without the substrate. For this reason, some modules of the workflow 190 are thoroughly selectable (in alternative embodiments, it should be recognized that no modules are selectable or unselectable).

As described above with reference to FIG. 9, the multilayer getter foil may be conveniently located in the working environment. This can be as easy as placing the trash in the same zone. For example, unlike getters with ceramic substrates, recycled getter foils and substrateless getters are economically worth the time and effort.

In an embodiment, workflow 190 continues at module 194 where the multilayer getter foil is shipped to a recycling facility. In an exemplary embodiment, the foil can be compressed to remove air. In an exemplary embodiment, because the foil is non-particulating, the compacting process is relatively clean and no particles should be missing when the compressed foil is shipped to a recycling facility. In an exemplary embodiment, the recycling facility may be located on site.

In an embodiment, workflow 190 continues with dissolving the foil substrate of the multilayer getter foil at module 196 at a temperature below the melting point of the high cost getter material. Foil substrates having a relatively low melting point, such as aluminum, can dissolve and leave other getter material such as steaming on the liquid substrate material surface. By way of example, and not limitation, getter materials comprising palladium and titanium are dissolved at, for example, higher temperatures than aluminum. If a heat source is in the field, the material provided for recycling may be exceptionally lightweight, because in the embodiment the foil constitutes the majority of the getter foil mass.

In an embodiment, workflow 190 continues with regenerating high cost getter material in module 196. In an embodiment, when the aluminum substrate is dissolved, palladium and titanium may fall off the surface.

In alternative embodiments, as known in the art of metallurgy, the getter material can be resuscitated in other ways, by way of non-limiting example, dissolving the getter foil in acid and removing the getter material electrolytically. . Similarly, after dissolving the foil substrate, the restored getter material may be chemically separated from the other electrolyte. Alternatively, the getter material may be heated to the melting point of any of the getter materials, leaving only the getter material (eg, palladium) to recover. In some cases, the restoration of expensive components, such as palladium, can be economically performed due to the relative low cost of the foil substrate, and the relative ease due to the expensive components can be separated from less expensive components or both. Can be.

10 depicts a workflow diagram 200 of a method for testing a multilayer getter, according to an exemplary embodiment. In an embodiment, workflow 200 begins at module 202 where the surface of the multi-layer getter has been tested. The test is by way of example and not limitation, and can measure the electrical resistance of a multilayer getter surface layer. It is known that features such as electrical resistance can change when the metal absorbs the desired gas. Thus, for example, measuring electrical resistance indicates whether the gas capacity of the getter will be exhausted.

Testing the electrical resistance of a multilayer getter can be difficult, for example, a multilayer getter (eg, getter 110 in FIG. 2) can be conceptualized as three resistances in parallel. Total resistance is the sum of the reciprocal of the three resistances. By way of example, and not limitation, gas permeable layer 112 of palladium, gas storage layer 114 of titanium, and foil substrate 116 of aluminum are exemplified. Since aluminum has a low resistivity, and in at least one embodiment will have a greater thickness than the palladium and titanium layers, if the contribution of aluminum is too high, the end result will always be that the measured resistivity will always be the resistivity of the aluminum layer.

Advantageously, if the substrate is an insulator (or has a relatively high resistivity), measurements will be possible. For example, a multi-layer getter (eg, getter 100 of FIG. 1) can be conceptualized as two resistances in parallel (ignoring the low reactivity of barrier 106). By way of example, and not limitation, gas permeable layer 102 of palladium, gas storage layer 104 of titanium, and barrier 106 of thin flexible insulator are exemplified.

In order to further reduce the resistance of the multilayer getter, the gas permeable layer is further separated. By way of example, and not limitation, interdigitation contact patterns may be located on one or more surfaces of several layers to further detect changes in resistance. In addition, as is known in the field of materials engineering, the use of polymer / metal multilayers, such as those used in the production of VIP bags, makes the measurement of gas permeable layers easier.

In an embodiment, workflow 200 continues at module 204 where the multi-layer getter is exchanged if the surface feature relates to the amount of target gas build up inside the surface layer. Advantageously, the surface layer will be gas permeable and the other layer will act as a reservoir. For example, the electrical resistance of the surface layer will not change substantially until the reservoir is full, so that the surface properties will be related to the amount of target gas that builds up inside the surface layer when the reservoir is full. .

As used herein, a reservoir represents a getter that absorbs an object, such as hydrogen, and does not release the object. This is different from non-storage getters that release water as a byproduct when the absorbed hydrogen combines with oxygen.

11 depicts a flowchart 210 of a method of constructing a getter foil, by the method of an exemplary embodiment. In an embodiment, workflow 210 begins at module 212 where the resistance of the foil is reduced by providing strong physical contact at the edge of the foil. Physical contact around the edges can be accomplished by using any of a number of techniques, and by way of example and not limitation, includes Kapton tape, screws and stainless steel weights.

In an embodiment, workflow 210 continues at module 214 where high frequency etching is performed on the foil. It has been found that some foils do not require chemical or other means to be pre-processed, and high frequency etching is sufficient. In an embodiment, high frequency etching is used to remove organic compounds and oxides, for example, in foil.

In an embodiment, workflow 210 continues at module 216 where the getter is positioned on the foil. In an embodiment, the workflow continues at module 218 with a catalyst layer disposed on the getter layer. The product is a multilayer getter foil.

The multilayer getters described herein can be formed in a number of forms. For example, the core of the multilayer wire may be a gas reservoir and may be covered with a gas permeable layer as described herein. Alternatively, the core of the multilayer pellet may be a gas reservoir and may be covered by a gas permeable layer, as described herein.

As used herein, the term "embodiment" is intended to be illustrative, not limiting, that the embodiment helps to illustrate.

It will be understood by those skilled in the art that the foregoing examples and preferred embodiments are exemplary and do not limit the scope of the present invention. By reading this specification and learning the drawings, it is intended for a person skilled in the art to make all changes, enhancements, equivalents, and improvements thereof within the spirit and scope of the present invention.

Claims (9)

A gas storage layer having a first surface and a second surface,
A gas permeable layer covering the first surface of the gas storage layer, and
And a barrier positioned on a second surface of said gas storage layer. The method of claim 1,
And the gas permeable layer is transparent to hydrogen. The method of claim 1,
Wherein said gas permeable layer dissociates hydrogen and said hydrogen diffuses into a metallic lattice of said gas permeable layer. The method of claim 1,
And the gas permeable layer is corrosion resistant. The method of claim 1,
And the gas permeable layer is oxidation resistant. The method of claim 1,
And the gas permeable layer comprises palladium. The method of claim 1,
And the gas permeable layer comprises a Group VIII transition metal. The method of claim 1,
The gas storage layer comprises at least one element selected from the group consisting of titanium, zirconium, tantalum, niobium, hafnium, vanadium, or yttrium, or transition metals, rare earths and aluminum and an alloy of at least one metal of the metals; Multilayer getter, characterized in that. The method of claim 1,
Wherein said gas permeable layer is a first gas permeable layer and said barrier is a second gas permeable layer.

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