CN113862617B

CN113862617B - Aluminum evaporation equipment for processing semiconductor thyristor

Info

Publication number: CN113862617B
Application number: CN202111348388.0A
Authority: CN
Inventors: 李敏; 陈金凌; 陈贵林
Original assignee: Jiangsu Weisenmei Microelectronics Co ltd
Current assignee: Jiangsu Weisenmei Microelectronics Co ltd
Priority date: 2021-11-15
Filing date: 2021-11-15
Publication date: 2022-08-09
Anticipated expiration: 2041-11-15
Also published as: CN113862617A

Abstract

The invention provides aluminum evaporation equipment for processing a semiconductor thyristor, which comprises a mounting substrate, an aluminum evaporator body and an evaporation box, wherein a power generation end of the aluminum evaporator body is fixedly connected with a lower tungsten rod, the top of the evaporation box is fixedly connected with an electric push rod, the output end of the electric push rod is fixedly connected with an upper tungsten rod through a ceramic block, and one side of the evaporation box, far away from the aluminum evaporator body, is communicated with a feeding pipe. The invention can feed materials without interruption, can detect the internal processing condition to ensure the safety of aluminum steaming, and solves the problems that the energy of a closed space is wasted in part of processing time for interrupting feeding after an aluminum wire is melted by the existing tungsten bar, so that the energy consumption of a plurality of aluminum evaporators is caused, the aluminum wire evaporation is carried out by supplementing the energy loss again, the processing is not continuous enough, and the aluminum wire is seriously consumed because the feeding is still carried out after the internal fault is not detected in the internal processing environment.

Description

Aluminum evaporation equipment for processing semiconductor thyristor

Technical Field

The invention relates to the technical field of semiconductor aluminum evaporation, in particular to aluminum evaporation equipment for processing a semiconductor thyristor.

Background

Thyristors may also be referred to as silicon controlled rectifiers. It is a high-power switch type semiconductor device, can work under the condition of high voltage and large current, and its working process can be controlled, and can be extensively used in the electronic circuits of controllable rectification, AC voltage regulation, contactless electronic switch, inversion and frequency conversion, etc.. The thyristor needs to be subjected to an aluminum evaporation process in the production process, and the aim is to evaporate a layer of aluminum on the cathode surface of the tube core of the thyristor for leading out an electrode. The process comprises the following steps: winding the aluminum wire with the surface treated on a tungsten rod, then placing a tube core on a platform, buckling the tube core on the platform through a bell jar to form a closed space, and vacuumizing the space; and then slowly electrifying the tungsten rod to melt the aluminum wire, and rapidly increasing the current to evaporate the aluminum solution on the tungsten rod so as to achieve the purpose of evaporating aluminum on the tube core.

The energy of a closed space is wasted in part of processing time for interrupting feeding after the tungsten bar melts the aluminum wire, energy consumption of a plurality of aluminum evaporators is caused, the aluminum wire evaporation is carried out by compensating energy loss, processing is not continuous enough, and the aluminum wire is seriously consumed because the feeding is still carried out after internal faults are caused because the internal processing environment cannot be explored.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide aluminum evaporation equipment for processing a semiconductor thyristor, which can feed materials without interruption and detect the internal processing condition to ensure the safety of aluminum evaporation, so as to solve the problems that the energy consumption of a plurality of aluminum evaporators is caused, the aluminum wire evaporation is carried out by supplementing the energy loss again, the processing is not continuous enough, and the aluminum wire is seriously consumed because the feeding is still carried out after the internal fault is not detected in the internal processing environment because the energy of a closed space is wasted in part of processing time for interrupting the feeding after an aluminum wire is melted by the existing tungsten bar.

In order to achieve the purpose, the invention is realized by the following technical scheme: an aluminum evaporation device for processing a semiconductor thyristor comprises a mounting substrate, an aluminum evaporator body and an evaporation box, wherein a lower tungsten rod is fixedly connected at a power generation end of the aluminum evaporator body, an electric push rod is fixedly connected at the top of the evaporation box, an output end of the electric push rod is fixedly connected with an upper tungsten rod through a ceramic block, a feeding pipe is communicated with one side of the evaporation box, which is far away from the aluminum evaporator body, a stop valve is communicated with one end of the feeding pipe, which is far away from the aluminum evaporator body, a pipe core is fixedly connected at the bottom of the inner wall of the evaporation box, an image sensor positioned at the bottom of the lower tungsten rod is fixedly connected at one side of the evaporation box, which is close to the aluminum evaporator body, a support plate is fixedly connected at one side of the evaporation box, which is far away from the aluminum evaporator body, an upper feeding box is fixedly connected at the top of the support plate, an air cylinder is fixedly connected at the front side of the top of the support plate, and a material pushing rod is fixedly connected at the piston end of the air cylinder, go up the workbin and keep away from the top of aluminium evaporimeter body one side and seted up the material loading mouth, the equal fixed connection in material loading incasement wall bottom both sides and stopper, go up workbin back fixedly connected with gasbag feed supplement mechanism, the inside slide bar that is provided with of material loading case, slide bar bottom fixedly connected with mount, the bottom fixedly connected with joint swager of mount constructs, material loading case top fixedly connected with mounting bracket, mounting bracket back fixedly connected with promotes canceling release mechanical system.

Further, gasbag feed supplement mechanism includes the baffle, it has the pole that supports to go up workbin back slidable mounting, support pole back fixedly connected with connecting plate, the first extension spring of the positive top fixedly connected with of connecting plate, one side and the last workbin fixed connection that the connecting plate was kept away from to first extension spring, the positive bottom fixedly connected with shrink gasbag of connecting plate, one side that the connecting plate was kept away from to the shrink gasbag is glued fixedly with last workbin.

Further, joint swager constructs including first folding cover piece, the first engaging lug of the equal fixedly connected with in both sides in the first folding cover piece outside, the inside movable mounting of first engaging lug has first installation axle, first installation axle outside cover is equipped with the second folding piece, the equal fixedly connected with second engaging lug in both sides in the second folding piece outside, the inside movable mounting of second engaging lug has second installation axle, the surface cover of second installation axle is equipped with the third folding piece, third folding piece top fixed connection has the stretch cord, the stretch cord keeps away from the one end and the mount outside fixed connection of third folding piece.

Further, promote canceling release mechanical system and include step motor, step motor output fixedly connected with rolling axle, the winding axle surface winding has the lifting rope, the one end and the mount top fixed connection of rolling axle are kept away from to the lifting rope.

Furthermore, the top of the feeding box is provided with a limiting shaft positioned on one side of the sliding rod, and the surface of the limiting shaft is provided with a sliding sleeve in a sleeved mode.

Further, the equal fixedly connected with silica gel pad in first folding nested piece, second folding piece and third folding piece top, the top that second folding piece and third folding piece are close to first folding nested piece one side all is the right angle setting.

Further, slide bar top fixedly connected with take-up plate, take-up plate bottom fixedly connected with second extension spring, second extension spring bottom and last workbin top fixed connection.

Further, one side fixedly connected with high temperature resistant glass that the evaporation box inner wall is close to image sensor, evaporation box inner wall fixedly connected with is close to the cleaning motor of image sensor one side bottom, the clean scraper blade of clean motor output fixedly connected with, clean scraper blade and high temperature resistant glass in close contact with.

The invention has the beneficial effects that: according to the invention, the evaporation condition in the evaporation box is detected by the image sensor, the air cylinder is started to push materials and feed materials, the air bag material supplementing mechanism is matched with the tungsten rod at the bottom of the feeding box, and the joint material pressing mechanism is matched with the lifting reset mechanism to promote the feeding and pressing materials after the material supplementing is finished, so that the stability of continuous feeding is ensured, the evaporation efficiency of the tungsten rod is improved, and the processing energy is saved.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a schematic perspective view of the present invention from the axial side;

FIG. 2 is a schematic rear view of a three-dimensional axial structure according to the present invention;

FIG. 3 is a schematic front view of the present invention;

FIG. 4 is a schematic front sectional view of the feeding box;

FIG. 5 is a schematic left-side sectional structure view of the feeding box;

FIG. 6 is an enlarged view of the structure at A in FIG. 3;

FIG. 7 is an enlarged view of the structure at B in FIG. 5;

fig. 8 is a schematic perspective view of the first, second and third folded pockets.

In the figure: 1. a mounting substrate; 2. an aluminum evaporator body; 3. an evaporation tank; 4. a lower tungsten rod; 5. an electric push rod; 6. a tungsten rod is arranged; 7. feeding pipes; 8. a stop valve; 9. a die; 10. an image sensor; 11. a support plate; 12. feeding a material box; 13. a cylinder; 14. a material pushing rod; 15. a feeding port; 16. a limiting block; 17. an air bag material supplementing mechanism; 171. a baffle plate; 172. a tightening rod; 173. a connecting plate; 174. a first tension spring; 175. contracting the air bag; 18. a slide bar; 19. a fixed mount; 20. a joint swaging mechanism; 201. a first folding nest block; 202. a first connecting lug; 203. a first mounting shaft; 204. a second folding block; 205. a second engaging lug; 206. a second mounting shaft; 207. a third folding block; 208. an elastic cord; 21. a mounting frame; 22. a lifting reset mechanism; 221. a stepping motor; 222. a winding shaft; 223. lifting a rope; 23. a limiting shaft; 24. a sliding sleeve; 25. tensioning the plate; 26. a second tension spring; 27. high temperature resistant glass; 28. cleaning the motor; 29. a cleaning blade.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.

Referring to fig. 1 and 3, fig. 1 is a schematic axial-side perspective view of the present invention; fig. 3 is a schematic front view of the present invention.

An aluminum evaporation device for processing a semiconductor thyristor comprises a mounting substrate 1, an aluminum evaporator body 2 and an evaporation box 3, wherein a power generation end of the aluminum evaporator body 2 is fixedly connected with a lower tungsten rod 4, the top of the evaporation box 3 is fixedly connected with an electric push rod 5, the output end of the electric push rod 5 is fixedly connected with an upper tungsten rod 6 through a ceramic block, one side of the evaporation box 3, which is far away from the aluminum evaporator body 2, is communicated with a feeding pipe 7, one end of the feeding pipe 7, which is far away from the aluminum evaporator body 2, is communicated with a stop valve 8, the bottom of the inner wall of the evaporation box 3 is fixedly connected with a pipe core 9, one side of the evaporation box 3, which is close to the aluminum evaporator body 2, is fixedly connected with an image sensor 10 positioned at the bottom of the lower tungsten rod 4, one side of the evaporation box 3, which is far away from the aluminum evaporator body 2, is fixedly connected with a support plate 11, the top of the support plate 11 is fixedly connected with an upper feeding box 12, and the front side of the top of the support plate 11 is fixedly connected with a cylinder 13, piston end fixedly connected with ejector beam 14 of cylinder 13, go up workbin 12 and keep away from the top of 2 one sides of aluminium evaporimeter body and seted up material loading mouth 15, the equal fixed connection in the inner wall bottom both sides of going up workbin 12 and stopper 16, go up workbin 12 back fixedly connected with gasbag feed supplement mechanism 17, it is provided with slide bar 18 to go up workbin 12 inside, slide bar 18 bottom fixedly connected with mount 19, the bottom fixedly connected with joint swager of mount 19 constructs 20, go up workbin 12 top fixedly connected with mounting bracket 21, mounting bracket 21 back fixedly connected with promotes canceling release mechanical system 22.

Referring to fig. 2, fig. 3, fig. 4, fig. 5, fig. 6, fig. 7 and fig. 8, fig. 2 is a schematic rear view axial side three-dimensional structure according to the present invention; FIG. 3 is a schematic front view of the present invention; FIG. 4 is a schematic front sectional view of the feeding box; FIG. 5 is a schematic left-side sectional structure view of the feeding box; FIG. 6 is an enlarged view of the structure at A in FIG. 3; FIG. 7 is an enlarged view of the structure at B in FIG. 5; fig. 8 is a schematic perspective view of the first, second and third folded pockets.

Gasbag feed supplement mechanism 17 includes baffle 171, it has tight pole 172 to support to go up workbin 12 back slidable mounting, support tight pole 172 back fixedly connected with connecting plate 173, the first extension spring 174 of connecting plate 173 front top fixedly connected with, one side and last workbin 12 fixed connection that connecting plate 173 was kept away from to first extension spring 174, connecting plate 173 front bottom fixedly connected with shrink gasbag 175, one side that shrink gasbag 175 kept away from connecting plate 173 is glued with last workbin 12 and is fixed, baffle 171 can prevent shrink gasbag 175 from floating from top to bottom, make shrink gasbag 175 can bounce connecting plate 173 fast, make connecting plate 173 drive and support tight pole 172 and slide backward, it drives the aluminium bar and slides forward to support tight pole 172, make the aluminium bar move to material pipe 7 department, first extension spring 174 accessible pulling force drives connecting plate 173 and resets after the material loading is accomplished.

The joint pressing mechanism 20 comprises a first folding sleeve block 201, first connecting lugs 202 are fixedly connected to two sides of the outer side of the first folding sleeve block 201, a first mounting shaft 203 is movably mounted inside the first connecting lugs 202, a second folding block 204 is sleeved outside the first mounting shaft 203, second connecting lugs 205 are fixedly connected to two sides of the outer side of the second folding block 204, a second mounting shaft 206 is movably mounted inside the second connecting lugs 205, a third folding block 207 is sleeved on the surface of the second mounting shaft 206, an elastic rope 208 is fixedly connected to the top of the third folding block 207, one end of the elastic rope 208, far away from the third folding block 207, is fixedly connected to the outer side of the fixing frame 19, the two sides of the first folding sleeve block 201 can enable the second folding blocks 204 on the two sides to be turned over downwards through the first mounting shaft 203, the first folding sleeve block can be folded when being lifted upwards, the aluminum bar above can be conveniently dropped to the bottom of the feeding box 12 for feeding, and meanwhile, the spherical surface outside the third folding block 207 can guarantee that the inner wall of the feeding box 12 can not be scratched, the second folding block 204 and the third folding block 207 which are turned downwards can be turned upwards to reset through the elastic rope 208, so that the aluminum bar can be conveniently compressed again.

Promote canceling release mechanical system 22 and include step motor 221, step motor 221 output fixedly connected with rolling axle 222, rolling axle 222 surface winding has lifting rope 223, lifting rope 223 keeps away from rolling axle 222 one end and 19 top fixed connection of mount, it is rotatory to start step motor 221 drives rolling axle 222, make rolling axle 222 drive lifting tensile rolling, can drive mount 19 rebound when lifting rope 223 rolling, make mount 19 cooperate first folding cover piece 201, the stable whereabouts of aluminium bar is piled up in last workbin 12 bottom to second folding piece 204 and third folding piece 207 messenger's aluminium bar, elastic cord 208 drives third folding piece 207 both sides upset flat cloth that resets upwards after accomplishing the promotion, be convenient for compress tightly the aluminium bar once more.

Go up the workbin 12 top and offer the spacing axle 23 that is located slide bar 18 one side, spacing axle 23 surface cover is equipped with sliding sleeve 24, and spacing axle 23 can carry out the abrasionproof to lifting rope 223 and decrease the processing, and with last workbin 12 top wearing and tearing when avoiding lifting rope 223 rolling, the sliding sleeve 24 frictional force when can eliminating wearing and tearing improves the stability of lifting rope 223 rolling.

First folding cover piece 201, the equal fixedly connected with silica gel pad in second folding piece 204 and the third folding piece 207 top, the top that second folding piece 204 and third folding piece 207 are close to first folding cover piece 201 one side all is the right angle setting, the silica gel pad can make the aluminium bar fall down at first folding cover piece 201, can not collide with the loss when second folding piece 204 and the third folding piece 207 top, the inboard that is the right angle setting simultaneously can be stable pushes down the aluminium bar, prevent that second folding piece 204 and third folding piece 207 from upwards overturning.

The top of the sliding rod 18 is fixedly connected with a tensioning plate 25, the bottom of the tensioning plate 25 is fixedly connected with a second tension spring 26, the bottom of the second tension spring 26 is fixedly connected with the top of the feeding box 12, the tensioning plate 25 can be matched with the second tension spring 26 to enable the sliding rod 18 to move downwards, and the sliding rod 18 is matched with the fixing frame 19 to drive the first folding sleeve block 201 to compress the aluminum rod stably for feeding.

One side fixedly connected with high temperature resistant glass 27 that the inner wall of evaporation case 3 is close to

image sensor

10, 3 inner wall fixedly connected with of evaporation case is close to the cleaning motor 28 of image sensor 10 one side bottom, cleaning motor 28 output end fixedly connected with cleaning blade 29, cleaning blade 29 and high temperature resistant glass 27 in close contact with, high temperature resistant glass 27 damages when can prevent high temperature evaporation aluminium, start cleaning motor 28 simultaneously and can drive the upset of cleaning blade 29 and clear away the residue evaporation fog on high temperature resistant glass 27 surface, guarantee image sensor 10's the accurate nature of detection.

The working principle is as follows: when the aluminum bar is pushed to a larger extent, the first tension spring 174 is reset by tension to drive the connecting plate 173 to move forwards, the connecting plate 173 drives the tightening rod 172 to push the aluminum bar to the upper material pipe 7, when the aluminum bar is pushed to the front and back, the connecting plate 173 drives the connecting plate 173 to move backwards by the contraction of the air bag 175, the connecting plate 173 drives the tightening rod 172 to move backwards, the second tension spring 26 drives the tightening plate 25 to move downwards, the tightening plate 25 can match with the tension of the second tension spring 26 to enable the sliding rod 18 to move downwards, the slide bar 18 is matched with the fixing frame 19 to drive the first folding sleeve block 201 to press the aluminum bar stably, so that the aluminum bar falls vertically, the aluminum bar is aligned horizontally again, continuous feeding is facilitated, a manual feeding gap is eliminated, the bottom of the tensioning plate 25 is provided with a proximity sensor, the absence of the aluminum bar moving downwards to an extreme position of the tensioning plate 25 is known through the proximity sensor, feeding is completed through the feeding port 15, after the feeding is completed, the stepping motor 221 is started to drive the winding shaft 222 to rotate, the winding shaft 222 drives the lifting and stretching winding, the lifting rope 223 can drive the fixing frame 19 to move upwards when winding, the fixing frame 19 is matched with the first folding sleeve block 201, the second folding block 204 and the third folding block 207 to complete downward overturning and shrinking actions, so that the aluminum bar stably falls down to be stacked at the bottom of the feeding box 12, and after the lifting is completed, the elastic rope 208 drives the two sides of the third folding block 207 to overturn upwards to reset and lay flat cloth, be convenient for compress tightly the aluminium bar through the pulling force of second extension spring 26 once more, can drive clean scraper blade 29 upset through starting cleaning motor 28 and clear away the residue evaporation fog on high temperature resistant glass 27 surface, guarantee image sensor 10's the accurate nature that detects, real-time detection aluminium silk evaporation picture, high-efficient energy saving, whether the inside aluminium silk evaporation picture of detectable is unusual simultaneously, avoids causing the aluminium bar loss.

While there have been shown and described what are at present considered the fundamental principles and essential features of the invention and its advantages, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing exemplary embodiments, but is capable of other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. The utility model provides an aluminium evaporation equipment is used in semiconductor thyristor processing, includes mounting substrate (1), aluminium evaporimeter body (2) and evaporating chamber (3), its characterized in that: the aluminum evaporator comprises an aluminum evaporator body (2), a power generation end of the aluminum evaporator body (2) is fixedly connected with a lower tungsten rod (4), the top of the evaporation box (3) is fixedly connected with an electric push rod (5), the output end of the electric push rod (5) is fixedly connected with an upper tungsten rod (6) through a porcelain block, one side of the evaporation box (3) far away from the aluminum evaporator body (2) is communicated with a feeding pipe (7), one end of the feeding pipe (7) far away from the aluminum evaporator body (2) is communicated with a stop valve (8), the bottom of the inner wall of the evaporation box (3) is fixedly connected with a pipe core (9), one side of the evaporation box (3) close to the aluminum evaporator body (2) is fixedly connected with an image sensor (10) positioned at the bottom of the lower tungsten rod (4), one side of the evaporation box (3) far away from the aluminum evaporator body (2) is fixedly connected with a support plate (11), the top of the support plate (11) is fixedly connected with an upper material box (12), the front side of the top of the supporting plate (11) is fixedly connected with an air cylinder (13), a piston end of the air cylinder (13) is fixedly connected with a material pushing rod (14), the top of one side, away from the aluminum evaporator body (2), of the material loading box (12) is provided with a material loading opening (15), two sides of the bottom of the inner wall of the material loading box (12) are fixedly connected with a limiting block (16), the back of the material loading box (12) is fixedly connected with an air bag material supplementing mechanism (17), a sliding rod (18) is arranged inside the material loading box (12), the bottom of the sliding rod (18) is fixedly connected with a fixing frame (19), the bottom of the fixing frame (19) is fixedly connected with a joint material pressing mechanism (20), the top of the material loading box (12) is fixedly connected with a mounting frame (21), and the back of the mounting frame (21) is fixedly connected with a lifting reset mechanism (22);

the air bag material supplementing mechanism (17) comprises a baffle (171), a resisting rod (172) is slidably mounted on the back of the feeding box (12), a connecting plate (173) is fixedly connected to the back of the resisting rod (172), a first tension spring (174) is fixedly connected to the top of the front of the connecting plate (173), one side, away from the connecting plate (173), of the first tension spring (174) is fixedly connected with the feeding box (12), a contraction air bag (175) is fixedly connected to the bottom of the front of the connecting plate (173), and one side, away from the connecting plate (173), of the contraction air bag (175) is fixedly adhered to the feeding box (12);

the joint pressing mechanism (20) comprises a first folding sleeve block (201), first connecting lugs (202) are fixedly connected to two sides of the outer side of the first folding sleeve block (201), a first mounting shaft (203) is movably mounted inside the first connecting lugs (202), a second folding block (204) is sleeved on the outer side of the first mounting shaft (203), second connecting lugs (205) are fixedly connected to two sides of the outer side of the second folding block (204), a second mounting shaft (206) is movably mounted inside the second connecting lugs (205), a third folding block (207) is sleeved on the surface of the second mounting shaft (206), an elastic rope (208) is fixedly connected to the top of the third folding block (207), and one end, far away from the third folding block (207), of the elastic rope (208) is fixedly connected to the outer side of the fixing frame (19);

slide bar (18) top fixedly connected with take-up plate (25), take-up plate (25) bottom fixedly connected with second extension spring (26), second extension spring (26) bottom and material loading case (12) top fixed connection.

2. The aluminum evaporation equipment for processing the semiconductor thyristor according to claim 1, wherein: the lifting reset mechanism (22) comprises a stepping motor (221), a winding shaft (222) is fixedly connected to the output end of the stepping motor (221), a lifting rope (223) is wound on the surface of the winding shaft (222), and one end, far away from the winding shaft (222), of the lifting rope (223) is fixedly connected with the top of the fixed frame (19).

3. The aluminum evaporation equipment for processing the semiconductor thyristor according to claim 1, wherein: go up workbin (12) top and offer spacing axle (23) that are located slide bar (18) one side, spacing axle (23) surface cover is equipped with sliding sleeve (24).

4. The aluminum evaporation equipment for processing the semiconductor thyristor according to claim 1, wherein: the equal fixedly connected with silica gel pad in first folding cover piece (201), second folding piece (204) and third folding piece (207) top, the top that second folding piece (204) and third folding piece (207) are close to first folding cover piece (201) one side all is the right angle setting.

5. The aluminum evaporation equipment for processing the semiconductor thyristor according to claim 1, wherein: one side fixedly connected with high temperature resistant glass (27) that evaporation case (3) inner wall is close to image sensor (10), evaporation case (3) inner wall fixedly connected with is close to cleaning motor (28) of image sensor (10) one side bottom, cleaning motor (28) output end fixedly connected with cleaning blade (29), cleaning blade (29) and high temperature resistant glass (27) in close contact with.