Patent Application
20070075644
1. Field of the Invention
The invention relates to a bonding system, having at least two components, whereby at least one consists of glass or glass-ceramics, the invention also relates to a bonding system method for the fabrication of a lamp which includes an inventive bonding system.
2. Description of the Related Art
Lamps including a bulb element, preferably a glass bulb element, can be found in greatly different embodiments, in multiple application areas, and in many types of lamps. For example, in the field of general lighting or automobile lighting or in thermal radiators, such as halogen lamps, incandescent lamps, high pressure or low pressure discharge lamps. Lamps can also be utilized, especially in miniaturized form, in so-called “backlighting” in connection with the background lighting of flat panel screens. In conventional light sources, such as incandescent lamps, halogen bulbs and gas discharge lamps, the transparent bulbs, particularly glass or translucent ceramics bulbs are in either an elongated cylindrical or in a stout bulging shape.
What is needed in the art is an efficient economical bonding system for the formation of lamps.
Lamps and applications are defined within the scope of one embodiment of the present invention whereby the bulb element is used as the first enveloping casing of the light emitting unit, for example the filament, and/or is used as a hermetically sealed body for inert or discharge gases. For the purpose of the present patent application these applications are referred to as “Type A” applications. This includes especially lamps of the “light bulb” or “halogen spot lamp” type where a current-carrying and therefore a highly heated tungsten spiral emits light, for example light bulbs or halogen spot lamps. In order to extend the life span as well as to increase the light yield, the bulbs in this type of lamp are filled with inert gases, such as krypton, argon or xenon. In the case of the halogen lamps the filler gases are halides which combine in the colder zones of the bulb interior with the tungsten which is volatilizing from the spiral and which disintegrates again on the hot tungsten spiral. The discharge of tungsten cause a “healing” on the hottest, that is the thinnest, areas of the spiral, thereby causing a life span extension. This is referred to as halogen circulation. The halogen additives also, practically completely, prevent blackening of the bulb through metal reflectors, and the inherent light current supply reduction since a condensation of metallic tungsten on the inside of the bulb is obviated through the formation of the tungsten halides. For this reason the bulb size can be greatly reduced and the filler gas pressure can be increased on halogen bulbs and the economic utilization of the inert gases krypton and xenon as filler gases is made possible.
In an alternative design of a Type A application the glass bulb forms the reaction space of a gas discharge. In addition, the glass bulb can act as carrier of light converting layers. Such lamps are, for example, low pressure fluorescent lamps as well as high pressure gas discharge lamps. In both instances supplied liquid or gaseous substances, frequently mercury (Hg), xenon (Xe) and/or neon (Ne), are stimulated to emit light, usually in the UV range, caused by an arc discharge between two electrodes which protrude into the bulb. In the instance of low pressure lamps, for example in back light lamps, the discrete UV lines are partially converted into visible lines thorough fluorescent layers. In medium pressure and high pressure discharge lamps the filler gases are put under high pressure of 100 bar or higher. Through impact effects as well as through formation of molecules, for example Hg, the discrete lines deteriorate into emission bands. The consequence of this is that quasi-white light is emitted. In addition there are optical active substances, for example halides of the noble earths, especially dysprosium halide or alkaline halides, which “complete” missing spectral components and increase the color fastness. The dependency of the white impression of the emitted light on the pressure is described in Derra et al. in “UHP-lamps: Light sources of extremely high brightness for projection television”, Phys. BI 54 (1998) No. 9 817-820. The disclosure content of this publication is included in its entirety as part of the disclosure content of the present application.
In “Type B” applications the glass bulb serves as a second enveloping casing, for example, for thermal encapsulation of the actual light emitting unit, as breakage or explosion protection, protection of materials and/or to protect the lamp user from harmful rays, especially UV rays.
Type B applications involve, for example, high pressure discharge lamps. The burners of high pressure discharge lamps, which are manufactured from silica glass or translucent ceramics (i.e. Al2O3, YAG-ceramics) are operated at the highest possible temperatures of up to 1000° C. or higher. The higher the operating temperatures are, the greater will be the color reproduction index and efficiency and at the same time decreasing the differences in light quality between individual lamps.
For the purpose of thermal insulation of the discharge vessel, a second enveloping glass bulb is inverted around the actual reaction body, whereby the space between them is mostly or essentially evacuated. In addition the enveloping bulb is doped with UV-blocking components.
Based on the different areas of application, different requirements present themselves regarding the utilized bulb glasses for Type A and Type B applications.
Type A applications require thermally highly stable materials, for example glasses which will not deform under the stresses caused by the close vicinity of the tungsten spiral or the high operating temperatures under pressure, especially the high pressure which occurs with the HID (High Intensity Discharge). In addition the glass bulbs are under an interior pressure of between 2 and 30 bar, in the case of halogen lamps or of up to approx. 100 bar or higher in the case of HID lamps. In addition, the bulbs must be highly chemically inert, in other words they must not react with the fillers. This means that no components from the bulb material may be released into the environment, especially no alkalis, OH ions or H2O. In addition it is advantageous if the transparent materials can be permanently hermetically sealed with the feeder metals. The bulb materials should be sealed, especially with W- or Mo-metal or with Fe—Ni—Co alloys such as Kovar and/or Alloy 42. In addition, leadthroughs having been sealed in this manner are considered to be stable, even during temperature change cycles.
In comparison cold lamp types, such as low pressure lamps, are thermally stressed only to an insignificant extent in the area of the leadthroughs. However, if such low pressure lamps are utilized as “backlight” lamps, then special requirements arise regarding UV blocking.
“Backlight” lamps are low pressure discharge lamps which can be utilized in miniaturized form in TFT (thin film transistor) displays, for example screens, monitors, and TV units for backlighting. Previously, multi-component glass based on silicate was used for this purpose. When used as “backlight” lamps, high demands are made upon the shielding of UV-light through the glass of the lamp, since other components, especially synthetic components, quickly age and deteriorate in flat screens under the influence of UV radiation.
In Type B applications the demands upon the temperature ratings and upon the chemical composition/resistance are generally lower than in Type A applications. The prevailing temperatures on the outside bulb in an HID lamp are for example 300° C.-700° C., depending upon the distance of the hot spot of the burner from the bulb. Accordingly, the leadthrough area is clearly colder then the bulb volume immediately adjacent to the burner. Depending on the power output of the burner, and due to very small distances of the hot-spot from the bulb's inside wall, wall temperatures of up to 800° C., or higher, can occur. As previously described these bulbs should possess high UV-blocking capabilities, especially in “backlight” applications.
Materials being utilized for glass bulbs in Type A applications are, according to the current state of the art, soft glass for light bulbs, alkali-free hard glass for automobile halogen lamps or silica glass for halogen lamps or HID lamps for general lighting or studio lighting. In this regard we refer you to Heinz G. Pfaender; SCHOTT Glass Encyclopaedia, mvg-Publishers, pages 122-128, and also German patents DE 197 47 355 C1, DE 197 58 481 C1, DE 197 47 354 C1 whose disclosure contents are made a part of this application and are included in their entirety.
For highest efficiency discharge lamps, having translucent aluminum oxide, which will withstand temperatures of 1100° C. or higher is used under the current state of the art as an alternative to silica glass. Regarding highest efficiency discharge lamps we refer, for example, to European Patent No. EP 748 780 B1 or Krell et al: “Transparent sintered corundum with high hardness and strength” in J. Am. Ceram. Soc. 86(4) 546-553 (2003), the disclosure content of which is included in the current application in its.entirety.
The material used in low pressure lamps can in comparison be a soft glass, for example borosilicate glass.
The preferred material for glass bulbs in Type B applications is silica glass or multi-component glasses, for example, Suprax (i.e. SCHOTT Type 8655 or DURAN-glass by SCHOTT GLAS, Mainz).
The utilization, particularly of glass ceramics, in the construction of lamps is described for example, in Patent GB 1,139,622. This describes a composite lamp, consisting of a glass ceramic component, as well as a silica glass window. The components are bonded together with a Cu-containing solder-glass. No details are given in GB 1,139,622 regarding the production of green glass bulbs or bodies or as to their further processing. The range of application is restricted to UV and IR lighting.
In several of the lamp types, which are known according to the current state of the art, for example, halogen lamps or HID lamps, the inside and/or outside lamp bulb consists of silica glass. The leadthrough, when viewed from the outside toward the inside, consists of W- or Mo-wire which is welded to a Mo-foil having a thickness of <100 μm, as well as an additional weld point to a W-wire, which leads into the interior of the lamp, for example to the W-filament or to W-discharge electrodes.
It is a generally known procedure to produce cylindrical HID lamps by fusing the outside bulb with the contact wires. One of the disadvantages of this design is to be found in the size of the required fusion zone. In order to increase the compact design, and/or design freedom, of lights with HID lamps as a light source, the outside bulb is joined with a base plate containing the leadthrough wires, via a frit ring thereby reducing the size of the fusion zone. A design of this type is already known from the publication WO 2004/077490 A1. A discoid glass, ceramics or glass-ceramics base plate is joined together with a hollow body in the embodiment of a quartz glass, soft glass or hard glass bulb by means of a frit ring. The joint area is characterized by the face of the outside bulb facing the base plate, and its width and it progresses toroidally. The joint area of a reflector, in place of the bulb, which can be used in the production of a reflector lamp, in place of a bulb lamp, is likewise toroidal.
The designs for lighting devices known from the current state of the art are characterized by high manufacturing costs as well as high energy costs and/or are of a large size.
It is an objective of the current invention to overcome the disadvantages of the current state of the art. Especially methods which will permit production of lighting devices that distinguish themselves by great compactness. The process provides that the components forming the lamp or the lamp bulb are largely hermetically sealed with each other.
In accordance with one embodiment of the current invention the connection between two components that are to be bonded with each other, whereby at least one of the components includes at least partially, preferably totally, of glass or glass ceramics, that is a glass-based material that can be produced on its own accord by the following methods:
In accordance with an especially advantageous design, both possibilities are combined, and in this instance a solder may be used.
The high temperature range is to be understood to be temperatures in the range of room temperature, that is approximately >50° C. to operating temperature of the lamp. In the case of HID lamps this is approx. 800° C. max. The low temperature range is characterized by temperatures≦room temperature or ≦50° C.
The first solution is characterized by the utilization of an inorganic glass-based solder material. Conventional Pb-borate composite glasses having the appropriate expansion reducing inert fillers can be used as soldering materials. Expansion adapted lead-free Bi—Zn borate composite glasses can also be used.
The connection of the individual components, which are to be joined with each other, whereby at least one of the components includes at least partially, preferably totally, of glass, glass ceramics or a glass-based material occurs through material sealing. This is characterized in that it is hermetically sealed and that it is stable at temperatures of up to T≧350° C., preferably T≧450° C. and preferably also as temperatures change.
The soldering process occurs by merging of the components that are to be joined through a diffusion process between the soldering material and the components which are to be joined. The melting temperature of the utilized soldering materials is to be below that of the melting temperature of the components which are to be joined, preferably in a range of 200° C. to 700° C. In an instance where a bulb/reflector is joined to a Fe—Ni-alloy (KOVAR, ALLOY42) this temperature should not exceed 600° C., ideally it should not be higher than 500° C.
The soldering process may be realized through the following cited methods:
The design according to b) incorporates optical fusing. Optical heating elements have the advantage of fusing glass gobs in a short time and locally, whereby the heating does not occur by way of surface heating and heat transport across the material itself, but occurs directly in the volume. This avoids thermally induced tensions in the glass gob, especially in thicker samples.
The state of the art for sIR is described in a series of publications. German Patent No. DE 199 38 807 describes the utilization of sIR radiation for the purpose of producing glass components from a glass gob, however, preferred use is for glass plates. German Patents DE 199 38 808, DE 199 38 811 as well as DE 101 18 260 describe the utilization of sIR radiation for the purpose of heating semi-transparent glass-ceramic source glasses, however, without reference to the joining between soldering material and the component which is to be connected.
The shape of the soldering material, in the initial state, will preferably be fitted to the shape of the components that are to be joined in the area of the joint, especially the joint surfaces. Dependent upon the type of the soldering material in its initial state, it is therefore possible to obtain locally very limited joining areas and thereby fusing areas.
In accordance with an especially advantageous embodiment of the present invention the material sealing is accomplished by way of soldering of the components in order to form a lamp bulb. This includes a first component in the form of a hollow body and a second component in the form of a discoid element. The hollow body is open, at least on one side. The opening is closed off by way of the discoid element. For this purpose, the discoid element is joined with the hollow body through the soldering material, whereby the connection is hermetically sealed. The discoid element may be a carrier for leadthroughs, especially metal leadthroughs. On the side of its opening, the hollow body has a surrounding surface, which is joined to the other component by inserting of the soldering material by way of material sealing. In the initial state the soldering material is then characterized by a toroidal shape.
Another inventive solution, in accordance with another embodiment of the present invention, is characterized in having compressive strain/tensile stress conditions between the interlocking components. These tensions are determined by the selection of the expansion coefficients of the individual components that are to be joined, their geometry and dimensioning, as well as their relative positioning to each other. Alternatively, or in addition, merely partial vacuum conditions may result in the formation of a positive hermetically tight joint without solder. Partial vacuum can, for example, be achieved through evacuation of a hollow space, formed by a discoid element, especially a plate and a hollow body in the form of a bulb/reflector, equipped with at least one opening. The evacuation may occur via a pump rod, for example a metal tube which is subsequently fused, for example, through laser heating.
A prerequisite for a connection without solder, by way of positive fitting under utilization of tensile stress/compressive strain conditions, is the dimensional accuracy of the source components prior to the actual joining process, especially regarding the plane-parallelism in the joint area of the components that are to be joined. This requires fitting precision with regard to
In accordance with an advantageous further development of the present invention a material seal is created by using a soldering material between the components, which are to be joined together with a positive fit.
Depending on the form of the connection as well as the dimensioning of the components that are to be joined, components of identical or different materials in various combinations can be joined together. Utilization occurs independently of the type of connection, without solder material or with solder material. The possible applicable materials for the components that are to be joined are classified with respect to their thermal expansion coefficients (CTE) in ppm/K into the following expansion groups, which are identified according to type. Components of the same or of different types can be combined, irrespective of whether or not a solder material is used.
Materials having a thermal expansion coefficient of CTE˜0 ppm/K are for example transparent lithium alumino-silicate (LAS) glass ceramics with the main crystal phase high quartz mixed crystal, such as ROBAX® or Zerodur® (Trademark of Schott Glas Mainz).
One example for a material having a CTE˜0.5/K is silica glass (SiO2).
Materials having an expansion coefficient CTE˜1.0 ppm/K are, for example, translucent lithium alumino-silicate (LAS) glass ceramics with the main crystal phase Keatit mixed crystal.
Partially or locally ceramized lithium alumino-silicates (LAS) glass ceramic having a green glass area, especially a discoid, partially or locally, ceramized lithium alumino-silicate (LAS) glass ceramic having a ring-shaped outer glass ceramic bonding contact surface and a green glass area progressing radially inward can be utilized as gradient materials of Type 1 Gr. The material may have a composition from the following composition ranges (in weight-% on oxide basis)
as well as conventional refining agents having a content of 0-4 weight %.
Transitional glasses of types 8228, 8229, 8230 of SCHOTT can be used as materials of Type 2, that is, having a CTE of between approximately 1.3 and 3.5 ppm/K. (also see DE 103 48 466)
DURAN 8330 (CTE=3.3 ppm/K) having an approximate composition of SiO2 81 weight %, B2O3 12.8 weight %, Al2O3 2.4 weight %, Na2O 3.3 weight %, K2O 0.5 weight % can also be used.
The glasses 8228, 8229, 8230 and 8330 encompass a glass composition range (weight %) of approximately 90% SiO2, approximately 0% to approximately 10% A1203, approximately 0% to approximately 15% B2O3 and less than approximately 5% R2O, whereby the content of Al2O3 and B2O3 together is approximately 7% to approximately 20% and R identifies an alkali metal of the group consisting of Li, Na, K, Rb and Cs.
As possible examples for materials having an expansion in the range of CTE20/300=3.5 to 5.5 ppm/K (Type 3) the following materials may be used;
g) Magnesium alumino-silicate (MAS) glass ceramics having a composition from the following composition range (in weight % on oxide basis):
as well as customary refining agents, for example SnO2, CeO2, SO4, Cl, As2O3 Sb2O3 in volumes of 0-4 weight %.
Materials of Type 3Gr contain gradient materials having locally different heat expansion coefficients CTE20/300 of between 0 and 4 ppm/K. Such materials can be produced, for example, through suitable processes from source materials, such as raw glass of glass ceramic of the Type LAS. Depending on the design of the component, the element may be in the form of a hollow body (tubular, bulbous) or a disc. A design having a locally ceramized tubular element with a green area at the end is known from WO2005/066088.
Examples for materials having an expansion in the range of CTE20/300 of between 5.5 and 9.0 ppm/K are (Type 4):
Hermetically tight bonding systems can be produced between material components from one expansion group as well as materials from different expansion groups.
Any inventive solution is applied in the fabrication of bonding systems with components where the first component is in the embodiment of a hollow body and the second component is a discoid element. Hollow bodies of glass or glass ceramics, for the production of lamps, may be in the form of tubes. If necessary, tubes can be converted into spherical or ellipsoid forms. Hollow spheres or hollow ellipsoids may, irrespective of a prior tubular form, also be produced directly through blowing or pressing.
Tubular glasses, glass ceramics, glasses or glass ceramics in a form that is similar to a tubular form can also be used as an outside bulb in HID (high intensity discharge) lamps, for example in high pressure metal halide, discharge lamps. In the present patent application “tubular” refers to a hollow body with an outer wall and at least one opening whose cross section is circular. In contrast, “similar to tubular” refers to the corresponding cross sections of another closed geometry, for example elliptic, oval or angular with rounded corners. Glasses and glass ceramics in the form of reflectors, which possess circular end surfaces in the area of the base, can also be joined with another material.
The present invention essentially refers to two different basic configurations. A choice can be made between these, depending upon the expansion regimen of the bonding partners and the geometric conditions of the lamp or the system.
Due to the continuously changing temperature conditions and especially contingent upon the activation and deactivation of the light devices, a hermetically tight seal must be assured in all operating conditions. Designs with the possibility of at least one-sided free seating for the creation of bonds from hollow bodies with an opening and discoid elements to close the opening are characterized in the following embodiments of the present invention with a view to the creation of a positive fit. All designs are intended for an embodiment of the hollow body, which provides a certain geometry describing the outside and inside circumference in the connection area, and an embodiment of the discoid element, preferably, however not imperatively (see below) with a protrusion on the face side with formation of a surface area describing the circumference of the protrusion for connection to the hollow body:
The described configurations may be utilized without solder material or with solder material for the production of a bonding system. If no positive fit is required and the bonding is to occur essentially through material sealing, that is through solder, contouring of the plate may also be dispensed with, since the plate does not have any toroid, discoid or groove-type structure.
In addition, depending on the desired type of bonding, these are coordinated with each other in the low temperature condition with regard to the expansion coefficient and are dimensioned such that a transitional or press fit between the individual effective surfaces of the individual components exists, at least in the high temperature condition, especially in the operating condition of the lamp. Preferably this exists also in the low temperature range.
In order to increase the degree of freedom regarding the selection of materials of the individual components, which are to be connected with each other, they are geometrically coordinated with each other in such a way that a gap exists in the low temperature range between the effective surfaces, which are fitted positively with each other in the high temperature range. The gap geometry is determined with a regard to the selected materials and their expansion coefficients.
In order to avoid undesirable tension conditions the geometry of the effective surfaces and/or the gap is optimized to the extent where shear forces between the individual, actively associating, surfaces of the components that are to be connected are avoided to a great extent. This is realized by according soft, in other words rounded embodiments of the locating surface.
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
a illustrates a bonding system in accordance with an embodiment of the present invention with a solder ring;
b illustrates with reference to Detail X according to
a illustrates an inventive bonding system according to an embodiment of the present invention without solder material;
b illustrates with reference to Detail X according to
a illustrates a bonding system according to another embodiment of the present invention with solder ring and radial gap;
b illustrates with reference to Detail X according to
a illustrates an inventive bonding system according to another embodiment of the present invention according to
b illustrates with reference to Detail X according to
a illustrates an inventive bonding system according to another embodiment of the present invention according to
b illustrates with reference to Detail X according to
c illustrates the detail of
a illustrates an inventive bonding system with solder material according to another embodiment of the present invention;
b illustrates with reference to Detail X according to
a illustrates a bonding system according to another embodiment of the present invention without solder material;
b illustrates with reference to Detail X according to
a illustrates a bonding system according to another embodiment of the present invention with solder material;
b illustrates with reference to Detail X according to
a illustrates a bonding system according to another embodiment with solder material and optimized gap geometry;
b illustrates with reference to Detail X according to
a illustrates a bonding system according to another embodiment of the present invention;
b illustrates with reference to Detail X according to
a illustrates a bonding system according to another embodiment of the present invention, with enlarged active surfaces compared with
b illustrates with reference to Detail X according to
a illustrates a bonding system according to a further embodiment of the present invention with optimized solder material application;
b illustrates with reference to Detail X according to
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate one preferred embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
Referring now to the drawings, and more particularly to
The preferred application for connection system 1 is in lamps or lights, whereby a hollow body 4 forms a bulb and a base plate 6 the bottom with leadthroughs for electrodes.
The bonding systems, in accordance with
Protrusion 8 may be in various embodiments and it possesses an effective surface 9 facing an inside circumference 11 of wall 12 of hollow body 4, preferably parallel to it. This means that the geometry of protrusion 8 and the area of wall 12 of hollow body 4, which represents an effective surface 10, are to be coordinated regarding their fit. In the illustrated example, hollow body 4 is characterized by at least one rotational symmetrical design in the connection area to base plate 6. Effective surface 10 as a partial surface of inside surface 20 of the hollow body 4 is therefore toroidal. The complementary effective surface 9 on protrusion 8 is also a toroid and arranged at an angle, preferably vertical to face 7. Depending upon the individual embodiment, this toroid surface in the form of effective surface 9 is formed either by a toroid, or in the illustrated example a discoid protrusion 8. The dimensions of protrusion 8 in circumferential direction in a rotational-symmetric design according to an axis A5, which when components 2 and 3 are connected, coincides with axis A4 of hollow body 4, are smaller in radial direction than those of base plate 6. Preferably both are characterized by a diameter of the inside circumference 20 of hollow body 4 in the connecting area by a diameter di and an outside diameter of protrusion 8 by a diameter da. Depending on the design, surface area 16 remaining between both diameters on face 7 serves as a direct contact surface for hollow body 4, especially face 14 or as illustrated in
The components, which are fitted together in this way, hollow body 4 and base plate 6, form a pair of effective surfaces 13 in the connection area, especially in the radial direction. In addition, face 14 of hollow body 4, which is facing base plate 6, is connected with surface area 16 of face 7 on base plate 6 through a solder material, especially a solder ring 15, providing a positive fit. The solder material further serves to fill the remaining leakages. The size of the joint is determined by the dimensions of solder ring 15, as well as the behavior of the solder material in its liquid state. Because of its only one-sided positive fit, hollow body 4 has no one-sided limitations, that is, limitations on outside circumference 21 for seating in a radial direction, in order words pointing away from effective surface 9 on protrusion 8. The solder ring is matched regarding its dimensioning, especially regarding its diameter and its width viewed cross directionally, with the dimensions of face 14 of hollow body 4. Thickness D, viewed cross directionally is less than height h8 of protrusion 8 relative to face 7.
According to
The individual components are designed and sized such that the fit in the joining area is dimensioned for positive locking, that is, between protrusion 8 and inside circumference 11 of wall 12 it is dimensioned at least as a transitional fit, and preferably forms a press fit already in the low temperature condition, or in other words at room temperature.
Face 7 and surface area 16 are preferably flat and at an angle of 90° to symmetrical axis A5 of base plate 6, and A4 of hollow body 4.
In the embodiment according to
For example, the following material combinations, which have been categorized according to their expansion coefficient, find a use in the construction of bonding system 1, according to
Example 1: Provides the first or second components from a material of the Type 1 group with CTE of between 4 and 0 ppm/K, whereby the zone with a CTE=4 ppm/K is in the connection area of the components and the components which are to be connected to them from a material of the Type 3 group having expansions in the range of CTE=3.5 to 5.5 ppm/K.
Example 2: Provides both components from a material of Type 3 with expansions in the range of CTE20/300=3.5 to 5.5 ppm/K.
Material Examples for Individual Components 2 and 3 for the Connections are:
In contrast,
For example, the following material combinations for the individual components which are to be connected can be used, at least in the connection area in one embodiment of bonding system 1 according to
Material Examples for Individual Components 2 and 3 of the Joints:
The optimum fit dimensions are dependent upon the CTE of the components, the respective temperature and the then occurring E-moduli and transversal contraction values of the materials. It is generally accepted that the transverse stresses, which are permitted to act upon the enveloping bulb, should be limited to a maximum of 15 MPa, preferably <10 MPa. The following applies approximately:
Tension (<10 MPa)=(E(T)·γ)/2·(1+ν(T)))
The optimum depth of the groove and its radius can then be determined.
If materials having the same heat expansion are used for components 2 and 3 the build-up of a compressive strain occurs opposite the inside wall of hollow body 4, due to the expansion of protrusion 8 of base plate 6 in a radial direction and due to the expansion of hollow body 4, with hollow body 4 also expanding again in the radial direction. At least a hermetically tight connection is created in the area of effective surfaces 9 and 10 in a radial direction and due to the progression of the effective surfaces, in a vertical direction, by way of form fitting. In addition, a hermetically close fit occurs between surface 14 facing base plate 6 and ring-shaped surface area 16.
The bonding of components 2 and 3 occurs under all operational conditions, especially at almost all temperatures at least by way of material sealing. In addition, positive fitting is also possible in the high temperature range.
For example, in one embodiment of bonding system 1, according to
Example 1: Provides the first or the second component from a zero or low-expanding material having 0≦CTE≦1.3 ppm/K and provides the second or first component from a material having expansions in the range of CTE between and including 3.5 to and including 5.5 ppm/K
Example 2: Provides the first or second component from a gradient material having CTEs of between 4 and 0 ppm/K (range of higher thermal expansions in the connecting area and the components, which are to be connected with them from a material having expansions in the range of CTE=3.5 to 5.5 ppm/K.)
Example 3: Provides both components from a material having expansions in the range of CTE=3.5 to 5.5 ppm/K.
Material Examples for Individual Components 2 and 3 of the Joints:
Relative to solder materials, conventional Pb-borate composite type glasses with suitable expansion reducing inert fillers can be used. Expansion-adapted lead-free Bi—Zn composite glasses or glasses on a phosphate basis can also be used.
Especially utilized were solder materials having the following characteristics:
Solder A (CTE20/300˜4.4 ppm/K; Tg˜325° C.; TSolder: 440° C.) or
Solder B (CTE20/300˜5.6 ppm/K; Tg˜445° C.; TSolder: 540° C.-570° C.)
In contrast,
For example in one embodiment of bonding system 1 according to
Example 1 Provides the first or second component from a material having expansions in the range of CTE=3.5 to 0.5 ppm/K and the second or first component from a material having expansions in the range of CTE=5.5 to ppm/K.
Material Example for Individual Components 2 and 3 of the Joints:
First or second component, preferably component 2 of borosilicate glass, for example Schott Type 8488 (SUPRAX), second or first component, preferably component 3 of AIOX
Example 2 Provides the first or second component from a material having expansions in the range of CTE=0 to 1.3 ppm/K and the second or first component from a material having expansions in the range of CTE=3.5 to 5.5 ppm/K.
Material Example:
First or second component, preferably component 2 of LAS glass ceramic, for example Schott ROBAX, second or first component, preferably component 3 of KOVAR.
b illustrates bonding system 1 in the low temperature state, while
Originating from the outside circumference on base plate 6 a flat surface area 22 extends to and joins the curved transitional area 23. The curvature is S-shaped and can be described by at least two radii R1 and R2 which are aligned opposite each other.
Since the geometry of hollow body 4 in the bonding area is adapted to that of the protrusion in the high temperature condition so that a flat contact of inside wall 20 of hollow body 4 with at least a partial surface of the outside circumference of protrusion 8 is assured in the high temperature condition, a flat fit in the area of outside circumference 24 of base plate 6 occurs only at room temperature. Gap 17 is characterized by different dimensions over its progression in radial and vertical directions. Shear forces, which would be exerted by base plate 6 upon hollow body 4 due to the expansion during heating, are kept to a minimum or are totally eliminated by this embodiment. In the low temperature condition the contact surface between base plate 6 and hollow body 4, especially face 14 is a flat surface according to
For example, in one embodiment of bonding system 1 according to
Example 1: Provides the first or second component from a material having expansions in the range of CTE=3.5 to 0.5 ppm/K and the second or first component from a material having expansions in the range of CTE=1.3 to 3.5 to ppm/K.
A material Example for Individual Components 2 and 3 of the Joints:
In this embodiment the expansion coefficients of individual components 2 and 3 and those of the solder material are coordinated with each other, being consistent with CTEH˜CTEB˜CRESolder
For example, in one embodiment of bonding system 1 according to
Example 1: Provides the first or second component in a gradient material having a CTE of between 4 and 0 ppm/K and the components which are to be joined in a material with expansions in the range of CTE=3.5 to 5.5 ppm/K.
Example 2: Provides both components being a material with expansions in the range of CTE=3.5 to 5.5 ppm/K.
Material Examples for Individual Components 2 and 3 of the Joints:
In contrast,
Groove 25 contains wall 12 of hollow body 4. Groove walls 26 and 27, which face in a radial direction, together with outside surface 21 of hollow body 4 and inside surface 20, respectively form an effective surface pair 13 and 13′. Face 14 of hollow body 4 is in contact with groove floor 28. During heating a pressure build-up occurs upon wall 12 of hollow body 4.
For example, in one embodiment of bonding system 1 according to
Example 1: Provides the first and second component in a zero- or low-expansion material having a thermal expansion of between CTE 0 and 1.3 ppm/K
A material example for individual components 2 and 3 of the joints are first and second components of silica glass
In contrast,
Hollow body 4 does not make contact with face 14 to groove floor 29, but instead is connected to it by way of solder ring 15. At the same time solder ring 15 fills up gap 17 and 17′, at least partially, vertically relative to the radial direction.
The example, according to
The connection is always through material sealing. In addition, a positive fit can be produced in the high temperature condition by virtue of the dimensioning of the components which are to be connected with each other.
For example, in one embodiment of bonding system 1 according to
Example 1: Provides the first or second component being of a gradient material having a CTE of between 4 and 0 ppm/K and the components, which are to be joined, of a material with expansions in the range of CTE=3.5 to 5.5 ppm/K.
A material example for individual components 2 and 3 of the joints are the First or second component, preferably component 2 being of partially ceramized LAS glass ceramic, and second or first component, preferably component 3 being Alloy 42.
The connection is always through material sealing. In addition, a positive fit can be produced in the high temperature condition by virtue of the dimensioning of the components which are to be connected with each other.
For example, in one embodiment of bonding system 1 according to
Example 1: Provides the first or second component being a gradient material having a CTE of between 4 and 0 ppm/K, and the components which are to be joined being of a material with expansions in the range of CTE=0 to 1.3 ppm/K.
Material example for individual components 2 and 3 of the joints are First or second component, preferably component 2 being of partially ceramized LAS glass ceramic hQMK and the second or the first component, preferably component 3 of LAS glass ceramic.
In contrast,
For example, the following materials, which are characterized through categorization into expansion groups, can be utilized, at least in the bonding area of the individual components, which are to be joined in one embodiment of bonding system 1 according to
Example 1: Provides the first or second component being a material having expansions in the range of CTE=1.3 to 3.5 ppm/K and the various components, which are to be joined with them, from a material having expansions in the range of CTE=5.5 to 9.0 ppm/K.
Material example for individual components 2 and 3 of the joints are the First or second component, preferably component 2 being of a transitional glass 8228, the second or first component, preferably component 3 being DUMET
In an additional design form, according to
In the low temperature range, in an embodiment according to
For example, the following materials, which are characterized through categorization into expansion groups can be utilized, at least in the bonding area of the individual components, which are to be joined in one embodiment of bonding system 1 according to FIGS. 11 or 12:
Example 1: Provides the first or second component being of from a material having expansions in the range of CTE=0-1.3 ppm/K and the components which are to be joined with them being of a material having expansions in the range of CTE=3.5 to 5.5 ppm/K.
Material Example for Individual Components 2 and 3 of the Joints:
While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claim.
Component Identification
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2005 047 006.8 | Sep 2005 | DE | national |
