WO2013143534A1

WO2013143534A1 - Tunnel furnace

Info

Publication number: WO2013143534A1
Application number: PCT/DE2013/100106
Authority: WO
Inventors: Thomas Rupp; Ralf Lechner
Original assignee: Curamik Electronics Gmbh
Priority date: 2012-03-30
Filing date: 2013-03-19
Publication date: 2013-10-03

Abstract

Tunnel furnace for heat treatment of treatment material, particularly for producing products made from at least one first metal or ceramic element, in the form of a metal or ceramic layer or a metal or ceramic plate for example, and from at least one second metal element, in the form of a metal layer or metal plate for example, by bonding said elements at high temperature, with a furnace housing forming at least one tunnel-like furnace space, with at least one heating device for heating the at least one furnace space and with at least one transporter having at least one transport element for transporting the treatment material in a transport direction through the at least one furnace space.

Description

tunnel kiln

The invention relates to a tunnel kiln according to the preamble

Claim 1 or 1 third

For example, the so-called "DGB (Direct Copper Bond) Technology" is known for bonding metal sheets or sheets (e.g., copper sheets or sheets) to each other and / or to ceramic or ceramic sheets using

Metal sheets or foils, in particular also those of copper or copper alloys, which have on their surface sides a layer or a coating of a chemical compound of the metal and a reactive gas, preferably oxygen. In this method, for example, in US-PS 37 44 120 or in DE-PS 23 19 854 described method, this layer or coating forms together with the adjacent metal, a eutectic (reflow) with a melting temperature below the melting temperature of the metal (eg copper) in that by laying the film on the ceramic and by heating all the layers they can be connected together, through

Melting of the metal or copper essentially only in the region of the melting layer or oxide layer,

This DCB method then indicates e.g. the following process steps: ® Oxidizing a metal foil, e.g. Copper foil so, which is a

uniform metal or copper oxide layer results;

• Laying the metal foil, such as copper foil on the

Ceramic layer;

Heating the composite to a process temperature between about 1025 to 1083 ° C, e.g. to about 1071 ° C;

• Cool to room temperature. Substrates prepared by this method (hereinafter also referred to as "DCB bonding") are hereinafter referred to as "DCB substrates", irrespective of the etaH used for the metal layers or sheets. The process itself is hereinafter referred to as "DCB bonding" regardless of the metal used for the metal layers or foils.

Also known is the so-called active soldering method (DE 22 11355, EP-A-1 53 618), for example for joining metallizations

Metal layers or metal foils, in particular also of copper layers or copper foils with KeramikmateriaL In this method, which is also used especially for the production of metal-ceramic substrates, at a temperature between about 800 - 1000 ° C a

Bonding between a metal foil, for example Kupferfoüe, and a ceramic substrate, for example, aluminum nitride ceramic, using a braze herrgesteilt, which in addition to a

Main component, such as copper, silver and / or gold also contains an active metal. This active metal, which is for example at least one element of the group Hf, Ti, Zr, Nb, Ce, establishes a connection between the solder and the ceramic by chemical reaction, while the

Connection between the solder and the Metali a metallic Hartlot- connection est. In particular, for the production of multi-layer products or for the necessary DCB bonding of metal to metal and / or metal on ceramics, but also for the active soldering of metal on ceramic as well as for burning thick film or metal thick film pastes on substrates, in particular ceramic substrates usually tunnel ovens are used. These include, inter alia, an oven housing forming an elongate tunnel-like furnace space (also called muffle) and a conveyor with a transport element in the form of a flexible and heat-resistant conveyor belt for transporting the Behandlungsiungsgut by heated with at least one heater oven space. The conveyor belt, which looks from a high-temperature resistant metallic material, forms a self-contained and circumferentially driven loop and is passed with an example upper loop length through the furnace chamber and lies with this loop length slidably provided on within the furnace chamber guides. The drive of the conveyor belt is such that it is pulled with its upper loop length through the furnace chamber.

This act on the conveyor belt alone to overcome the

Sliding friction between the conveyor belt and sliding guide considerable tensile forces. These lead u.a. to a permanent extension or elongation of the conveyor belt, while reducing the width of this band. For this reason, in known tunnel ovens, especially those for the DCB bonder? or active soldering or used to burn thick film or metal thick film pastes for the

Conveyor belt only a relatively short service life reachable, i. It is a relatively frequent change of the conveyor belt required, which means not only by the actual replacement of the conveyor belt, but also by the cooling and reheating of the tunnel kiln and for the reinstatement of the required tunnel kiln atmosphere a significant production downtime. It has to be taken into consideration that especially for DCB bonding, active soldering and burning in of thick film or metal thick film impurities in the tunnel area, a protective gas atmosphere with an exactly set oxygen content is required in order to achieve the respective

Treatment, i. to achieve the bonding, especially with the desired quality. Another major disadvantage known

Tunnel kilns is characterized by the sliding friction between the

Conveyor belt and the guides of the tunnel kiln results in a significant burden of the furnace interior and thus the local atmosphere caused by abrasion particles. Known is a transport system or a conveyor for tunnel ovens (DE 20 2010 01 461 U 1), whose transport elements consists of a roller adapter system with a plurality of rolls made of a ceramic material, which in a transport direction of the conveyor successive and spaced apart rollers form the

Transport surface, on which the material to be treated by the

Tunnel kiln is moved. The disadvantage here is, inter alia, that with the known system, a full-surface edition of the material to be treated is not possible, this is supported by spatially offset on the rollers.

Ceramic slideways serve to support the rollers.

The object of the invention is to provide a tunnel oven, which avoids the aforementioned disadvantages and in particular for the

"High-temperature bonding" of "multi-layer products is suitable." To solve this problem, a tunnel furnace according to claim 1 or 13 is formed.

The expression "substantially" or "approximately" in the sense of the invention means deviations from the exact value by +/- 10%, preferably by +/- 5% and / or deviations in the form of for the function

insignificant changes.

"High temperature bonding" in the sense of the invention means bonding or bonding at high temperature, i.e. at a temperature above 600 ° C,

"Multilayer products" are within the meaning of the invention, such products, which consists of at least a first element of metal or ceramic, for example in the form of a metal or ceramic layer: or metal or ceramic plate, and at least a second metal element, for example in the form of a Metal layer or metal plate, wherein these elements are connected by high-temperature bonding with each other. "Full-surface or essentially voüflächige edition" means in the context of the invention that the respective item to be treated with his

Transport element immediately adjacent side over the entire surface or in the

Essentially voüflächig rests on the transport element,

In a further development of the invention, the tunnel kiln, for example, is designed

the furnace housing seals the at least one furnace chamber in a gastight manner towards an environment at least at all circumferential sides extending in the transport direction,

and or

that the tunnel kiln for a DCB ~ bonding metal with metal,

For example, of metal or copper foils with metal or copper foils, or for a DCB bonding or active brazing of metal with ceramic, for example, metal or copper foils with ceramic or for the burning of thick film or Metalldickfiimpasten is formed, and / or

that the rolling elements and preferably also bearings and / or

Lagerwälzkörper and / or guides for the rolling elements and / or

Lagerwälzkörper consist of ceramic material,

and or

that the transport element sliding means are formed by a plurality of rolling elements in the form of rollers, which in the transport direction successively form a roller or roller track for the conveyor or for the at least one transport element,

and or

the rollers or rollers made of the ceramic material are freely rotatably mounted in the at least one furnace chamber on bearings likewise arranged in the at least one furnace chamber, preferably with rolling or ball bearings made of the ceramic material,

and or that the rolling or ball bearings have Lagerwälzkörper, which lie directly against formed by the rollers bearing or running surfaces., and / or

that the rolling or ball bearings have Lagerwälzkörper which are free, i. are arranged without a ball or Wälzkörperkäfig between the respective roller and a bearing or running surface of a bearing body, and / or

that the Transportelementgleitmittel, in particular the roller conveyor of several in the transport direction of the conveyor to each other

subsequent segments, each having a plurality of rolling elements, preferably rollers and associated bearings with Lagerwälzkörpern,

and or

the bearing bodies arranged on two opposite sides of a segment are connected to one another by at least one preferably releasable retaining clip,

and or

that the transport element meshing means are formed by rollers or rollers which are freely rotatably mounted on the conveyor or on its transport elements, and in that the rollers or rollers consist of the ceramic material and preferably cooperate with guides of the tunnel kiln also made of the ceramic material,

and or

that the transport elements are lubricants guided in ball guides balls on which the feed dog or the at least one

Transporting supports, and that the balls and preferably also the

Ball guides consist of the ceramic material,

and or

that nozzle openings are provided for introducing a gaseous medium, for example in the form of an inert gas and / or in the form of oxygen, into the at least one furnace space, wherein the

Nozzle openings at least partially on guides for the Transportelemenglitsitmiltel forming distribution pipes, for example to the

Ball guides forming distributor pipes are provided,

and or

that the transport element is a conveyor belt, which forms a self-contained loop which can be driven in rotation and which passes through the at least one tunnel space with a loop length, and / or

that the transporter of several adjoining

Transport elements or recordings is formed, that the recordings are moved as non-interconnected individual elements of a tunnel kiln inlet to a tunnel kiln exit and fed back from the tunnel kiln outlet to the tunnel kiln inlet, or that the recordings are connected together in a chain-link with each other to a circulating transport element,

and or

that the balls carried along with the transporter or with its transport elements or shots from a tunnel kiln inlet to a tunnel kiln outlet in the ball tracks are returned from the tunnel kiln outlet to the tunnel kiln inlet,

and or

that the nozzles on at least one manifold of a ceramic

Material are provided,

and or

that the ceramic material silicon nitride, silicon carbide,

Alumina is,

wherein the aforementioned features can be used individually or in any combination.

Further developments, advantages and applications of the invention will become apparent from the following description of

Embodiments and from the figures, all described and / or illustrated features are alone or in any Combination in principle subject of the invention, regardless of their summary in the claims or their dependency. Also, the content of the claims is made an integral part of the description.

The invention will be described below with reference to the figures

Exemplary embodiments explained in more detail. Show it:

Fig. 1 in a simplified representation and in section through

High-temperature bonding or DCB bonding produced metal

Ceramic substrate;

Fig. 2 in a schematic representation and in longitudinal section a

Tunnel kiln for producing the metal-ceramic substrate;

FIG. 3 is a schematic sectional view of the tunnel kiln of FIG. 2; FIG. 4 is a simplified representation of a plan view of a roller conveyor for guiding and supporting the transport element, together with a partial view of this transport element.

Fig. 5 in an enlarged view the storage of one of the rollers or

Rolling the roller conveyor of Figure 4;

Fig. 6 is a representation like Figure 5 in a further embodiment

the invention;

Figures 7 and 8 in a schematic representation similar to Figures 2 and 3, a further embodiments of the treatment or tunnel oven according to the invention.

Fig. 9 in a schematic representation and in longitudinal section another

Embodiment of the invention;

Fig. 10 and 1 1 in simplified sectional views the

Transport element sliding means of the tunnel kiln of Figure 9;

12 is a simplified representation of a plan view of a roller conveyor for guiding and supporting the transport element according to a further embodiment of the invention; Fig. 13 is an end view of a roller conveyor segment of the roller conveyor of Fig. 12;

FIG. 14 shows an individual view and a side view of one of the bearing bodies of the roller conveyor of FIG. 12; FIG.

Fig. 1 5 in an enlarged partial view the storage of a roll or

Roller of the roller conveyor of FIG. 12.

In the figures, 1 is a product in the form of a metal-ceramic substrate, which in a known manner from a ceramic layer 2, for example of alumina; Aluminum nitride, silicon nitride or aluminum oxide with zirconium oxide as well as made of MetailfoHen 3, such as copper foils metallizations made by high-temperature bonding, for example by DCB bonding, to each other

opposite surface sides of the ceramic layer 2 are provided.

For the production of the product 1, the treatment or tunnel kiln, schematically indicated by 4 in FIGS. 1 to 5, is used, inter alia. a horizontally open, elongated furnace housing 5 (muffle) with furnace chamber 5.1 and a feed dog 6, which in the embodiment shown in Figures 2-5 in a conventional manner of a closed loop forming and this over at least two

Deflections 7 and 8 guided conveyor belt 9 is illustrated, which with his in the figures 2 and 3 upper length by the appropriate manner, for example electrically or with a gas or liquid

Heating medium heated furnace chamber 5.1 is passed. The wall of the furnace housing 5 consists of a high heat-resistant steel or a nickel base alloy. The heating elements 10 serving for heating the oven space 5.1 are provided outside the oven space 5.1 and are controlled by thermosensors assigned to them. The transport element 9 consists of a plurality of chain elements or members, which are arranged adjacent to one another in both the transport direction A and transverse to the transport direction A and hinged together, so that the lattice-like, flexible

Conveyor belt 9 results. The conveyor belt 9, the links and joints are made of a high heat resistant steel.

By a suitable drive, the conveyor belt 9 is driven circumferentially so that the respective upper loop length 9.1 moves in the direction indicated in the figure 2 with the arrow A transport direction through the furnace chamber 5.1, from the inlet 4.1 to the outlet 4.2 of

Tunnel kiln. The drive of the conveyor belt 9 via the deflection 8, so that the upper loop length is drawn 9.1 through the furnace chamber 5.1.

In the furnace chamber 5.1 open at appropriate areas nozzles 14 for introducing a protective gas and in particular during DCB bonding and for the controlled introduction of oxygen or a protective gas-oxygen mixture with regulated Sauerstoffanteii. To produce the products 1, the corresponding item to be treated is 1 .1, which in the illustrated embodiment in each case of the stack assembly consisting of the two elalSfolien 3 and arranged between them

Ceramic layer 2 is formed, placed on the kiln inlet 4.1 on the top of a horizontal transport plane forming loops length 9.1 and then moved with the conveyor belt 9 through the furnace chamber 5.1. The finished product 1 is removed from the oven outlet 4.2. One of the two

Deflections 7 and 8 is also designed for tensioning or retightening of the conveyor belt 9. To support the upper loop length 9.1 not only in the area of the kiln inlet 4.1 and the kiln outlet 4.2, but in particular in the furnace chamber 5.1 Transportelementgleitmittel are provided, which in the in Figures 3 - 5 illustrated embodiment are realized by a plurality of rollers or rollers 1 1.1, which form a roller conveyor 1 1 and each freely rotatable in the oven housing 5 or at a local

/ vtaschinengestellt 12 are stored both ends. The rollers 1 1 .1 are oriented with their axes parallel to the horizontal transport plane of the conveyor belt 9 and perpendicular to the transport direction A.

The upper loop length 9.1 thus forms a horizontal or im

Essentially horizontal transport plane for the item to be treated 1 .1 or for the respective product 1.

To support the rollers 1 1 .1 are ball bearings 13, which consist for example of an inner bearing ring 1 3.1, an outer bearing ring 13.2 and a plurality of balls 13.3, between the bearing rings 13.1 and 13.2 or between the local ball treads are arranged. At least the rollers 1 1 .1 and also the ball bearings 1 3

including their bearing rings 1 3.1 and 13.2 and balls 1 3.3 each made of a ceramic material or material, which not only has a high temperature resistance but also a high mechanical strength at the maximum treatment or bonding temperature.

The upper loop length 9.1 lies with its underside on the rollers 1 1 .1 or on the roller conveyor formed by these rollers. As a result, the force required for moving the conveyor belt 9 and exerted by the deflection 8 on the conveyor belt 9 tensile force is substantially reduced. In particular, the disadvantages of a pure

Slideway of the conveyor belt 9 within the tunnel oven 4 avoided, but at least substantially reduced. This also means, inter alia, that the quality of the manufactured products 1 possibly impairing and resulting from a sliding abrasion between the conveyor belt 9 and a conveyor belt guide is avoided, and above all, a replacement of the conveyor belt 9 because of excessive elongation of this Conveyor belt is no longer required or only in much larger Zeitvervaiien, ie with the invention results in a significant increase in the life or service life of the conveyor belt. 9

FIG. 6 shows, in a representation similar to FIG. 5, a ball bearing 1 3a for the rollers 11 .1. The ball bearing 13a is different from the

Ball bearing 1 3 characterized in that the inner ring 13.1 is omitted and the balls 1 3.3 against the respective roller 1 1.1 directly toSiegen.

FIGS. 7 and 8 show, as a further embodiment, a tunnel kiln 4 a, which differs from the tunnel kiln 4 essentially only in that the transporter 6 b is made of a large number of, for example

plate-shaped or substantially piattförmigen receptacles 15 is formed. The recordings 1 5 are each provided with a plurality of rollers 16, with which the receptacles 5 on guides 1 7 of the

Support tunnel kiln 4a. At least between the inlet 4a.1 and the outlet 4a.2 of the tunnel kiln 4 close the individual receptacles 15 close to each other, so that they by a schematically illustrated in Figure 7 by the arrow 18 thrust by pushing through the

Tunnel space 5.1 are moved in the transport direction A, wherein the rollers 16 each roll on the guides 1 7.

The material to be treated is placed on the receptacles 1 5 at the inlet 4a. 1 and the finished product 1 is removed from the receptacles 1 5 at the outlet 4. The receptacles 15 are moved back in the direction of transport A 'from the outlet 4a.2 to the inlet 4a via a transport path designated schematically by 19 in FIG. In this case, it may be expedient for the transport path 19 to run within an inner space that is thermally insulated and / or heated relative to the surroundings, as indicated by the broken line 20 in FIG strong cooling of the receptacles 15 during their return to the inlet 4a.1 to avoid.

Basically, however, it is also possible to guide the transport path 19 through a further furnace chamber 5.1 corresponding furnace chamber of the tunnel oven 4a or a separate tunnel kiln, so that the transport path 19 for the production of products 1 from the

Material to be treated 1 .1 is used. The rollers 1 6, for example, each formed by a ball bearing. At least the rollers 16 and the receptacles 15 consist of the

heat-resistant and also mechanically high-strength ceramic material.

Above, it was assumed that the recordings are 15 separate elements. Be understood, there is also the possibility that

Images 1 5 joints articulated to form a closed loop forming and circumferentially drivable transport element. FIGS. 9 and 0 show, as a further embodiment, a tunnel kiln 4b, in which the transport element sliding means are formed by a multiplicity of balls 21 in two parallel ball guides 22 extending in each case in transport rib A. The feed dog 6b of the tunnel oven 4b is again formed in this embodiment by a plurality of receptacles 23, for example, plate-shaped or im

Are formed substantially plate-shaped. At least between the inlet 4b.1 and the outlet 4b.2 close the receptacles 23 close to each other, so that they are moved, for example by pushing with a schematically indicated in Figure 9 with the arrow 24 shear drive through the furnace chamber 5.1. In this case, the receptacles 23 are each supported in the region of their two sides oriented in the transport direction A on the balls 21, which are sealed in the associated ball guides 22 are provided consecutively, and when moving the

Receivers 23 are also moved in this transport direction of the inlet 4b1 to the Ausiass 4b2. For treating the material to be treated 1 .1 each receptacle 23 is placed at the inlet 4b.1 on the there already provided with a plurality of balls 21 sections of the ball guides 23 and then the treated 1 .1 placed on the respective receptacle 23. The product 1 produced in each case is removed from the receptacle 23 at the exit 4b.2. Thereafter, the empty receptacle 23 is removed from the Kugeiführungen 22 and moved back over a transport path 25 together with such balls 21, which have also passed to the Ausiass 4b.2, to the inlet 4b.1. On the transport path 25, the receptacles 23, for example, are also on provided with the balls 21 ball guides. Analogous to the Transportirecke 19 and the transport path 25 preferably extends in a relation to the environment thermally insulated and / or heated room 20 or by another used for the manufacture of products 1 furnace chamber of the tunnel oven 4b or another tunnel kiln, the balls 21 and the ball guides 22nd

According to FIG. 10, the two ball guides 22

For example, each formed by two tubes 26 which are parallel and slightly spaced from each other with their longitudinal extent in

Transport direction A and A 'oriented and secured in a suitable manner to a frame 27 of the tunnel oven 4b. The tubes 27 are preferably used at the same time for supplying the protective gas and / or oxygen and / or the protective gas-oxygen mixture in the furnace chamber 5.1 and are for this purpose formed with a plurality of nozzle openings 26.1, nozzle openings 26.1 are preferably also located at the mutually facing peripheral regions of Tubes 26 with the additional advantage that the space 28 formed between the tubes 26 is cleaned by blowing out of the local nozzle openings 26.1 gas by blowing. At least the balls 21 and the ball guides 22 and the elements forming them, eg tubes 26 are made of the heat-resistant and also mechanically high-strength ceramic material.

FIG. 11 shows an embodiment in which the

Transport element sliding means, i. the lubricant for the receptacles 23 are not formed by mechanical lubricants, but by a pressurized gas. For this purpose, two tubes 29 are provided along the path of movement of the receptacles 23 and below the receptacles 23, which at their the

Shooting 23 side facing form a plurality of nozzle openings 29.1. During operation of the relevant tunnel kiln, the tubes 29 are subjected to a pressurized inert gas or inert gas-oxygen mixture, so that this gas then exits under pressure from the nozzle openings 29.1 and thereby the receptacles 23 in the area oriented in the direction of transport A pages support a compressed gas cushion 30 formed by the exiting compressed gas. The tubes 29 in turn consist of the heat-resistant and also mechanically high-strength ceramic material.

Figures 12 and 13 show the transport system or a

Transport path 6c of a tunnel kiln, which in turn the

Transport element or conveyor belt 9 and the

Transportelementgleitmittel for the upper length 9.1 of the conveyor belt forming roller conveyor 1 1 c with a plurality of successive in the transport direction A rollers or rollers 1 1 c.1. These are oriented with their roll axes horizontally or substantially horizontally and perpendicular to the transport direction A and rotatably mounted at both ends in bearing housings 31 which are formed in the illustrated embodiment, each strip-like oriented with their longitudinal extent in the transport direction A. The conveyor belt 9 in turn sees of a plurality of chain elements or members, both in the transport direction A consecutive, as well as arranged transversely to the transport direction A next to each other and are hinged together, so that there is a grid-like, flexible conveyor belt. The conveyor belt 9 or

its links and joints are made of a high temperature or heat resistant material, preferably made of a corresponding steel.

The rollers Ί 1 c.1 are mounted at both ends with bearings 32 freely rotatable about its roller axis in the bearing housings 31, namely ball bearing or roller bearing. For this purpose, each bearing 32 on several Lagerwälzkörper 33, which are balls in the illustrated embodiment and each bear directly against a rolling or bearing surface 34 of the respective roller 1 1 c.1 or roll on this bearing surface 34, respectively, in the illustrated embodiment from the peripheral surface of a cross-section reduced end 1 c.1 .1 of the respective roller 1 1 c.1 is formed. Furthermore, the Lagerwälzkörper 33 bear against an outer bearing surface 35 of the bearing body 31, which in the illustrated

Embodiment is formed in each case by the inner surface of a provided in the bearing body 31 recess 36. The Lagerwälzkörper 33 thus roll directly on the respective roller 1 1 c.1 or

Roller section 1 1 c.1 .1 and the inner surface of the relevant

Bearing recess 36 from. The bearings 32 thus have neither at

Rolling bearings usual outer and inner races, nor a cage for the Lagerwälzkörper 33 on.

Since the bearing surface 34 is formed in each case by the peripheral surface of the reduced in cross-section end 1 1 c.1 .1 of the respective roller 1 1 c.1 and partly at the transition from the larger roll diameter to the reduced roll end 1 1 c.1 .1 , Axial support for the Lagerwälzkörper 33 is achieved on the rollers 1 1 c.1, so that in the likewise axial support of the Lagerwälzkörper to the bearing bodies 31 and in the bearing openings 36, the bearing 32 not only as a radial bearing, but also act as Axialiager. At least the rollers 1 l c.1 and the Lagerwälzkörper 33 are made of a heat-resistant and mechanically high-strength ceramic material. The bearing body 31 are made for example of a high temperature resistant material, such as steel or else also from the heat-resistant and mechanically high-strength ceramic material.

Another special feature of the roller conveyor 1 1 c is that it consists of several consecutive in the transport direction

Roller track segments 37 sets together, each consisting of two bearing body 31 on the two longitudinal sides of the respective segment 37 and a plurality of rollers 1 1 c mounted in these bearing bodies 31 in the manner described above. During assembly of the transport system or the transport path 6c, these segments are before mounting the

Transport belt 9 of at least one end of the tunnel oven successively inserted into this, in the preassembled state. In order to hold together the bearing body 31, the rollers 1 1 c.1 and the elements of the bearings 32 together, i. To secure the preassembled state of the respective segment 37, each segment 37 has at least one e.g. made of a heat-resistant metal, holding element 38 which serves as an assembly aid and extends on the underside of the relevant segment 37 between the two bearing bodies 31 and these each with a

angled section 38.1 engages behind. The holding elements 38 remain, for example, in the tunnel oven, but they are preferably removed when inserting the respective segment 37. The assembly of the segments 37 on the tunnel kiln is then carried out so that each segment 37 is at least as far pushed into the tunnel kiln 4c, that the bearing body 31 with their rollers 1 1 1 c.1 facing away from the outside

Abutment elements 39 come to rest, which are required in the tunnel kiln for proper positioning of the segments 37. Following this, the holding element 38 can already be released from the segment 37 and then completely inserted into the tunnel oven, in which the cohesion of the segments 37 is ensured by the support members 39. With appropriate design of the holding elements 38, these can be removed even after each complete assembly of a segment 37 of this. The holding elements 38 are

For example, retaining plates or retaining clips, e.g. made of spring steel.

It has been assumed above that the roller conveyor formed by the segments 37 1 1 c as Transportelementgleitmittel for the

Conveyor belt 9 is used, but in principle it is also possible, instead of the conveyor belt 9 plate-shaped recordings or

Provide transport elements, as shown in Figure 1 5 at 40, which are then pushed, for example, in the direction of transport A immediately adjacent to each other on the roller conveyor 1 1 c through the tunnel kiln 4c and on which the respective item to be treated .1 for a DCB bonding or active soldering is arranged.

Material to be treated 1 .1 consists for example of the

Ceramic layer 2 and the metal foils 3 on the two surface sides of the ceramic layer 2. To an undesirable joining of the lower

To avoid Metallfoiie 3 with the consisting of a mechanically high-strength ceramic material transport elements or receptacles 40, these are provided at least on its upper side with a release layer 41, which is made for example with a high porosity of ceramic material, e.g. from Muiiit and / or Al 2 O 3 and / or TiO 3 and / or ZrO 2 and / or MgO and / or CaO and / or CaCO 2.

As a heat-resistant and also mechanically high-strength ceramic

Material, i. As a ceramic material, which is not only stable at the maximum treatment temperature, but also has the required mechanical strength at this temperature, is in all the above-described embodiments preferably a

Ceramic with a low coefficient of thermal expansion, For example, at least one ceramic from the group SiC, SI3N4, Al2CO, AlN, BN, B4C, B-SiC, Si-SiC, N-SiC and / or Muliit. This ceramic material is particularly suitable for the rollers 1 1 .1 and their bearings 1 3 and 1 3a, the receptacles 1 5 and their rollers 16, the guides 7, the balls 21, ball guides 22 and the tubes 29.

All versions but is common that the transport element is a flat or substantially flat and / or full-surface or in the

Essentially full-surface support for the material to be treated 1 .1 forms and the Transportelementgleitmittel are in the furnace chamber 5.1 exclusively in the interior of this furnace chamber 5.1 and no elements of Transportelementgieitmittel are led out of the furnace chamber 5.1, so with the exception of the inlet 4.1, 4a.1 or 4b. and of

Outlet 4.2, 4a.2 and 4b.2 results in an outwardly closed furnace chamber 5.1 and openings in the wall or in the furnace housing 5 are avoided, through which ambient air enter the furnace chamber 5.1 and / or inert gas or inert gas oxygen Mixture could emerge from the oven chamber 5.1. The invention has been described above in various embodiments. It is understood that further changes and modifications are possible without thereby departing from the inventive concept underlying the invention.

LIST OF REFERENCE NUMBERS

1 product

1.1 Treatment Case

2 ceramics

3 metal foil

4, 4a, 4b, 4c tunnel kiln

4.1, 4a.1, 4b.1 inlet

4.2, 4a.2, 4b.2 outlet

5 oven casings or muffle

5.1 oven room

6, 6a, 6b, 6c, 6d transport route

7, 8 redirection

9, 9a, 9b Transportelemeni

9.1 upper loop length of the transport element. 9

10 heating device

11, 1c roller conveyor

11.1, 11c.1 roller

11c.1.1 roll end

12 machine frame

13, 13a ball bearings

13.1, 13.2 bearing ring

13.3 Ball

14 nozzle

15 recording

16 roll

7 leadership

18 drive

19 transport route

20 protected space

21 ball 22 ball guide

23 recording

24 drive

25 transport sirens

26 pipe

26.1 nozzle opening

27 machine frame

28 space

29 pipe

29.1 nozzle opening

30 compressed gas cushion

31 bearing body

32 bearings

33 Lagerwälzkörper

34, 35 storage area

36 recess or bearing opening

37 segment

38 retaining element or mounting aid 38.1 section of the retaining clip 39 furnace-resistant support element

40 transport element or recording

41 separating layer

A, A 'transport direction

Claims

claims

Tunnel kiln for heat treatment of material to be treated (1 .1), in particular for producing multilayer products (1) and / or for burning thick-film or metal thick-film pastes, with a furnace housing (5) forming at least one tunnel-like furnace space (5.1), with at least one heating device (10) for heating the at least one furnace chamber (5.1) and at least one

Transporter (6, 6a, 6b) with at least one transport element (9, 1 5, 23, 40), with which the treated material (1 .1) in a transport direction (A) is transported through the at least one furnace chamber (5.1), with between the at least one conveyor (6, 6a, 6b, 6c, 6d) and the tunnel kiln (4, 4a, 4b, 4c) acting Transportelementgieitmitteln (1 1 .1, 16, 21, 30) for supporting the transporter (6, 6a , 6b, 6c, 6d), and with rotatable and / or abzubizbaren bearing or support elements or rolling elements (1 1 .1, 1 1 c.1, 16, 21),

characterized

in that the at least one transport element (9, 15, 23, 40) forms at least one flat or essentially level and / or voluminous or substantially voluminous support for the respective item to be treated (1 .1), and that the rotatable and / or rollable Warehouse or

Support elements or rolling elements (1 .1, 1 c.1, 16, 21) the

Make transport element slip means.

Tunnel kiln according to claim 1, characterized in that the

Oven housing (5) the at least one furnace chamber (5.1) at least at all, in the transport direction (A) extending peripheral sides gas-tightly closes to an environment.

Tunnel kiln according to claim 1 or 2, characterized in that the tunnel kiln (4, 4a, 4b, 4c) for a DCB bonding of metal to metal, For example, of metal or copper foils with metal or

Copper foils, or for DCB bonding or active soldering of metal with ceramic, for example of metal or copper foils with ceramic or for the burning of thick-film or metal thick-film pastes,

4. Tunnel kiln according to one of claims 1 - 3, characterized in that the rolling elements (1 1 .1, 1 1 c.1, 1 6, 21} and preferably also bearing (1 3, 1 3a, 32) and / or Guides (1 7, 22) for the rolling elements (1 1 .1, 1 1 c.1, 1 6, 21) consist of ceramic material.

5. tunnel oven according to claim 4, characterized in that the

Transportelementgleitmittel of a plurality of rolling elements in the form of rollers (1 1 .1, 1 c.1) are formed in the transport direction (A) consecutively a roller or roller conveyor (1 1, 1 1 c) for the conveyor (6 , 6a, 6b, 6c, 6d) or for the at least one

Transport element (9, 1 5, 23, 40) form, and that the rollers or rollers (1 1 .1, d) of the ceramic material in the at least one furnace chamber (5.1) also arranged in the at least one furnace chamber (5.1) Bearings (1 3, 1 3a, 32), preferably with rolling or ball bearings of the ceramic material are freely rotatably mounted.

6. Tunnel oven according to claim 5, characterized in that the rolling or ball bearings (32) bearing rolling bodies (33) which lie directly against the rollers (1 c.) Formed bearing or running surfaces (34), wherein bearing or running surfaces ( 34) are preferably each formed on a reduced in cross-section roll end (1 1 c.1 .1) and / or at a transition to the reduced end of the Waizen (1 c.1 .1). 7. Tunnel oven according to claim 5 or 6, characterized in that the rolling or ball bearings (32) Lagervvälzkörper (33), which is free, ie without a ball or Wälzkörperkäfig between the respective roller (1 1 c.I) and a bearing or running surface (35) of a bearing body (31) are arranged.

8. Tunnel kiln according to one of the preceding claims, characterized

in that the transport element sliding means, in particular the roller conveyor (1 1 c), consist of several in the transport direction (A) of the

Transporter (6c, 6d) on adjacent segments (37), each of which has a plurality of rolling elements, preferably rollers (1 1 c.1) and associated bearing (32) with Lagerervvälzkörpern (33).

9. Tunnel oven according to claim 8, characterized in that arranged on two opposite Siegenden sides of a segment (37)

Bearing body (31) by at least one mounting aid or by at least one preferably releasable retaining element (38) are connected to each other.

10. Tunnel kiln according to one of the preceding claims, characterized

characterized in that the Transportelementgleitmittel of rollers or rollers (16) are formed, which are freely rotatably mounted on the feed dog (6a) or on the transport elements (15), and that the rollers or rollers (16) consist of the ceramic material and preferably with also made of the ceramic material guides (1 7) of the tunnel furnace (4a) cooperate.

1 1. Tunnel kiln according to one of the preceding claims, characterized

characterized in that the Transportelemenie lubricant in

Ball guides (22) guided balls (21) are on which the feed dog (6b) or the at least one transport element (23) is supported, and that the balls and preferably also the

Ball guides (22) made of the ceramic material.

12. Tunnel oven according to one of the preceding claims, characterized by nozzle openings (14, 26.1, 29.1) for introducing a gaseous medium, for example in the form of a protective gas and / or in the form of oxygen, in the at least one furnace chamber (5.1), wherein the nozzle openings {26,1} at least partially

Guides for the TransportelementgSeitmitteS forming manifolds (26, 29), for example, to the ball guides (22) forming

Distribution pipes are provided,

1 3. Tunnel kiln for heat treatment of treated material (1 .1),

in particular for producing multi-layer products (1), with a furnace housing (5) forming at least one tunnel-like furnace space (5.1), with at least one heating device (10) for heating the at least one furnace chamber (5.1) and with at least one

Feed dog (6, 6a, 6b) with at least one transport element {9, 15, 23), with which the material to be treated (1 .1) is transported in a direction of transport (A) through the at least one furnace space (5.1), with between at least one transporter (6, 6a, 6b) and the

Tunnel furnace (4, 4a, 4b) acting Transportelementgleitmitteln (1 1 .1, 1 6, 21, 30) for supporting the conveyor (6, 6a, 6b),

characterized,

in that the at least one transport element (9, 5, 23) has at least one plane or essentially flat and / or full surface or in the

Substantially full-surface support for the respective item to be treated (1 .1) is formed, and that the Transportelementgleitmittel of at least one compressed gas cushion or volume (30) are formed, which is generated by one of a plurality of nozzles (29.1) exiting compressed gas.

14. Tunnel kiln according to one of the preceding claims, characterized

in that the transport element is a conveyor belt (9) which forms a self-contained loop which can be driven in rotation and, with a loop length (9.1), extends through the at least one tunnel space (5.1). 1 S.Tunnelofen according to one of the preceding claims, characterized

in that the conveyor (6a, 6b) is formed by a plurality of adjoining transport elements or receptacles (15, 23) such that the receptacles (1 5, 23) are not connected to one another by a tunnel oven inlet (4a.1, 4b .1) to one

Tunnelofenausiass (4a, 2, 4b.2) moves and from the tunnels outlet (4a.2, 4b.2) to the tunnel oven inlet (4a.1, 4b.1) are returned, or that the receptacles (1 5, 23) chain-like with each other are connected to a rotating transport element with each other.

16. Tunnel oven according to one of the preceding claims, characterized

in that the balls (21) entrained with the feed dog (6b) or with its transport elements or receptacles (23) from a tunnel oven inlet (4b.1) to a tunnel kiln outlet (4b.2) in the ball tracks (22) are discharged from the tunnel kiln ( 4b.2) are returned to the tunnel oven inlet (4a, 1).

1 J.Tunnelofen according to any one of claims 1 3 - 6, characterized in that the nozzles are provided on at least one distributor tube (29) made of a ceramic material.

18. Tunnel kiln according to one of the preceding claims, characterized

characterized in that the ceramic material is silicon nitride,

Silicon carbide, alumina is.