US3252120A

US3252120A - Dick karmiggelt by

Info

Publication number: US3252120A
Authority: US
Publication date: 1966-05-17
Anticipated expiration: 1983-05-17

Description

May 17, 1966 M, SCHRDER ET AL 3,252,120

PHOTOELECTRI C CELL Filed Jan. 28, 1963 INVENTORS HERMAN M. SCHRDER 7' DICK KRMIGGELT BY o GENT

PHTOELECTRIC CELL Herman Mathieu Schrder and Dick Karmiggelt, Emmasingel, Eindhoven, Netherlands, assignors to North American Philips Company Inc., New York, N.Y., a

corporation of Delaware Filed Jan. 28, 1963, Ser. No. 254,201 Claims priority, application Netherlands, Feb. 5, 1962, 274,386 12 Claims. (Cl. 3381-19) The invention relates to an electric circuit element, more particularly a photo-electric cell or light-dependent resistor comprising a preferably elongated body in a tubular envelope fitting around the body with a certain amount of clearance space, in which, viewed in a cross section, the clearance space around the periphery of the body inside the envelope is filled, at 'least over part of the height of the body, with a soft or viscous mass.

The photosensitive active element or body, which frequently comprises an elongated, e.g. plateor rod-shaped, body, owing to the sensitiveness of its electrical properties to atmospheric influences, must be screened by a viscous or soft mass in a further envelope.

With a view to the use of the electric circuit element, the envelope must have a minimum size, matching the shape and size of the active body. This-involves the problem of filling uniformly the usually very small clearance in cross section over theheight of the body with a viscous or soft mass in order to obtain a uniform protection of the sensitive body parts. Since the opening of such an envelope to be closed is located comparatively near the body, there is furthermore the problem ofvembedding the body in the filling mass, frequently a silicoorganic grease, so that the filling mass'does not soil or smear the edge of the opening to be closed owing to `lack of uniformity in the filling, which would involve difficulties in adhesion during the subsequent sealing of the envelope.

In the manufacture of eg. photo-electric cells having a plate-shaped, electroded, photo-sensitive body this body may be embedded in a viscous mass and be introduced into a at, glass tube, which is open at one end and fits around said body with a certain amount of clearance, by

' slipping the photo-sensitive body into said tube, which has previously been filled with the mass to an extent such that after the introduction of the body the mass fills the tube to the desired height upto the desired distance from the opening. In carrying out this method of embedding by hand, it appeared that along the narrow side walls the filling mass was pushed upwards to a greater height than along the broad front or' rear walls, thus smearing the edge of the opening to be closed. With some forms of photo-electric cells this difficulty could be avoided by embedding the body not by hand but by centrifugal force. With other embodiments, however, e.g. those in which the body to be embedded consisted of a metal support with a photo-sensitive plate attached thereto, the ylack of uniformity and soiling of the edge were found to occur even in the case of introduction by centrifugal force.

From experiments -carried out in connection with the invention it was found that said non-uniform filling is inter alia due to the fact that the clearance space available, viewed in across section, along the periphery of the body exhibits local differences. With the aforesaid fiat photo-electric cells for example, there is preferably -left a greater clearance along the narrow side walls than on 'United States Patent Y O 3,252,120 Patented May 17|, 1966 lCe the broader front and rear walls, since the distance between the side walls cannot be satisfactorily controlled accurately in the manufacture of the envelope. If a small clearance is desired in a given direction in a cross section, it may be desirable to provide a larger clearance in another direction in the cross section in order to simplify the introduction of the body into the envelope. It has furthermore been found that the irregular pushing-up of the filling mass was even worse and could not be avoided by centrifugal force in the event of too great a difference in specific weights of the body and filling mass, which is the case for example with photo-electric cells having a cooling plate fastened to the photo-sensitive body.

On the basis of these results the invention has for its object inter alia to provide a simple and efficacious embodiment of an electric circuit element, particularly a photo-electric cell, which permits of avoiding said difficulties in manufacture in a simple manner and to provide, in addition, suitable methods of manufacturing such an electric circuit element.

With an electric circuit element, particularly-a photoelectric cell of the shape described above, the clearance space in the plane of the cross section along the periphery of the body exhibits differences and in accordance with the invention the embedded body is locally provided, along its height, with one or more extensions, which partly fill in the local cross sectio'n the placesv of greater clearance space. The invention thus permits of manufacturing circuit elements with the desired differences in clearance spaces between the envelope and the body and of compensating by the presence of the local extensions for the differences in clearance spaces in a simple .manner to an extent such that a uniform filling of the viscous or soft mass is obtained without smearing the opening to be sealed. With the manufacture of e.g. photo-electric cells it was now found to be possible to embed those structures also by hand, which could be embedded only by centrifugal force without smearing the opening. In such an embodiment e.g. of a photo-electric cell, in which case the invention is particularly interesting, the body has the shape of a plate and is formed, in the case of a photoelectric cell, at least partly by a photo-sensitive plate provided with-an electrode system, while the envelope is formed by a fiat tube surrounding the body with a certain amount of clearance space. According to the invention this embodiment is characterised in that the clearance space in a cross-section at the narrow side walls of the at tube is larger than that at the front-and at the rear walls, while at the edges of the plate-shaped body, along its height, one or more extensions are provided, which partly fill the clearance spaces along the two side walls in the local crosssection and are located opposite each other. The body may be composed of a plurality of parts or layer. The invention may also be applied in a similar manner to a photo-electric cell of the shape described above, in which the photo-sensitive plate is arranged ona supporting plate, preferably of-'glass or ceramic material. It wasl furthermore found, by surprise, to be possible to fill uniformly such embodiments of circuit elements, for example photo-electric cells in which the mass weight between the body and the viscous mass, for example owing to the presence of a metal cooling plate in the body, exhibited such differences that the body could not be embedded by centrifugal force without in- -volving the said difficulties, by using the extensions and also owing to the braking effect of the contraction of the clearance space. With an advantageous embodiment of such a photo-electric cell in the aforesaid, fiat tubular envelope the body is formed mainly by an electroded photo-sensitive body, Which is arranged, if desired with the interposition of an `insulating layer, on part of metal cooling strip, for example of copper.

- The extensions may be formed, for example, by locally thickened par-ts of a ring surrounding the body or they may be provided locally on the edge of the body by punching. In a particular embodiment of the invention, in which the body has the shape of a plate and the envelope is formed by a fiat tube having a larger clearance spaced along the `two side walls, the edges of the plate-shaped body are held in metal clamping bodies, which may serve at the same time as electrode voltage supplies and which are provided locally by extensions formed'by tags, which may be formed from the body itself by punching. In order to simplify the introduction of the body into the envelope, the extensions are preferably at an angle of`less than 90 to the edges of the body, and are orientated towards .the sealing area or open end lof the envelope. The extensions may engage the wall of the envelope, so that a further braking effect in the embedding operation is obtained. However, in order to avoid a dierence in the braking effect owing to tolerances in the measurements of the section of the envelope, the extensions are preferably provided so that in the local cross section they do not touch simultaneously the inner wall of the envelope. In order to ensure an optimum, uniform embedding, .preferably more than two extensions are provided along the embedded height at regular intervals, the number of extensions being higher the greater is the height to be ernbedded. One of the extensions is preferably provided on or near Athat part of the body which comes first into contact with the viscous mass during the embedding operation.

The manufacture may be carried out so that the body is first slipped into the envelope, after which the grease is introduced and distributed for example by centrifugal force, while the extensions have aneffect conducive to the uniform distribution. However, the embedding operation is preferably carried out by slipping the body with the extensions described above into an envelope previously filled with the mass, which may, in some cases, be carried out manually and preferably by centrifugal force.

The invention will now be described more fully with reference to a few embodiments and the diagrammatic drawing.

FIGS. la, 1b, 1c, show one embodiment of a photoelectric cell in a longitudinal sectional view, a longitudinal cross sectorial view at the place of the clamping bodies'. and in a further transverse sectional view, respectively.

FIG. 2 shows diagrammatically a stage of the manufacture of the photo-electric cell shown in FIG. l.

The invention will first be described with reference to a particular embodiment of a photo-resistance cell of the kind shown in FIGS. 1a, 1b and 1c.

The envelope consists of an elongated, flat glass tube 1, open at the bottom side, the external height of which is about 40 mms., while the external section has the dimensions mms. x 5 mms. This glass tube 1, which has a wall thickness of about 0.8 mm., accommodates with a certain amount of clearance a plate-shaped photoresistance body `2, for example of CdS, having a height of 32 mms. and a cross section of 11 x l mms?. On one side 3 of the photo-resistance plate 2 there is provided an electrode line system formed by two combshaped, interlaced line electrodes 4 and 5, applied by vaporisation and having a thickness of for example 5 x 0.5M. The other side 6 of the photo-resistance plate 2 is fastened by means of an adhesive layer 7 for example of an epoxy resin, having a thickness of 0.1

mm., to part of a metal cooling plate 8, for example of copper, having a thickness of about 1.4 mms. ther part 9 of said cooling plate projects beyond the sealed opening for conducting heat away and has an opening 10 for fastening to a chassis. The seal consists of a synthetic substance 11, for example an epoxy resin, comprising a filling plate 12 of quartz for compensating the expansion of the cooling plate part 9, also taken to the outside.

The photo-resistance plate 2 and the cooling plate 8 are held on the sides in U-shaped

clamping bodies

13 and 14, having a thickness of 0.2 mm., for example of copper or nickel and the assembly thus constitutes a body, which ts in the envelope 1 with a certain amount of play. O n the front side 3 each of said

clamping members

13 and 14 is electrically connected to one of the comb-shaped electrodes 4 and 5 respectively. The

clamping members

13 and 14 are electrically insulated lfrom the cooling plate 8 by means of a mica plate 15 of 0.2 mm. in thickness (see FIG. 1c). The

clamping members

13 and 14 terminate on the bottom side in

supply conductors

16 and 17, which are also taken to the outside through the seal. the edges bythe clamping

members

13 and 14 and for-med by Ithe photo-resistance plate 2, the adhesive 'layer 7, the cooling part 8 and the mica plate 15, has, viewed in a cross section (see FIG. 1c) a small clearance space which differs along the periphery of the body with respect to the envelope 1. The clearance space between the rear envelope wall and the mica plate 15 and that between the front envelope wall and the active side 3 of the body is not more than '0.3 to 0.4 mm., whereas on either side of the body between Ithe side walls of the envelope 1 and the

clamping members

13 and 14 respectively a clearance space is left, the section of which is approximately semi-circular and has a radius of about 1 mm. The composite body is embedded substantially uniformly throughout its height in a soft or viscous mass 18, which may consist of a Silico-organic grease, for example Dow Corning High-Vacuum Grease, up to the proximity of the seal, Where a small air chamber 19 is left as an expansion space for the grease.

In order to obtain this uniform embedding `four metal l extensions 20 are provided at regular intervals along the height of the body at the place of the larger clearance space on the sides on either side of the body, sa-id extensions filling partly, inthe local cross section (see FIG. 1c) the clearance spaces on Ithe sides and thus substantially leveling out the clearance in vthe cross section along the periphery. Said extensions are shaped in the form of tags, which are integral with the clamping members 13 aud 14 and are obtained from the sides of said clamping members by local embossed parts, which may be seen from FIG. 1b, where the remaining cavities 21 in the sides of the clamping member 13 are shown. In order to simplify the embedding of the body the extensions 20 are at an angle of less than 90 to the sides and are orientated towards the seal. One pair of extensions is provided on the upper side of the body,

i.e. on that part which comes first into contact with the viscous 4or soft mass 18 during the embedding operation (see also FIG. 2). In the embodiment shown in FIGS. 1a, 1b and 1c these extensions 20 are arranged so that they do just not touch the inner wall of the envelope 1 (see FIG. 1c). However, the extensions 20 may protrude further so that they locally engage the inner wall, in which case a' sometimes desirable additional, advantageous braking effect along the Wall can be obtained. Owing to these extensions 20 a uniform filing along the periphery of and throughout the height of the body may be obtained during embedding by centrifugal force although the clearance spaces are different and the mass weight of the body considerably exceeds that of the filling mass 18 owing to the provision of the cooling plate 8, 9.

A fur- The body bounded at f body to be embedded.

FIG. 2 shows diagrammatically a stage of the manufacture yof a photo-electric cell shown in FIGS. la,4 1b and 1c.

The envelope 1 is held in the holder 30, shown diagrammatically and introduced into a centrifugal machine 31, which is.adapted to rotate about the shaft 32, the upper end of the envelope 1 being closed and being spaced apart from the shaft 32 by a distance of about 13 cms. The envelope 1 is previously filled with a quantity of soft mass 18 to an extent such that, after the body is embedded, the clearance is uniformly filled up to the height indicated in FIG. 1a. On the filling mass 18 is disposed the body to be embedded, which consists of the clamping

members

13 and 14 and the mica plate held thereby, the cooling plate (8, l9), the adhesive layer and the photo-sensitive plate 2. The body to be embedded is provided with the extensions 20, as is shown in FIGS. 1a, 1b and 1c. By centrifuging with a speed of 2200 rev./min. for about 5 minutes the plate-shaped body is uniformly embedded in the filling mass 18 so that the configuration shown in FIGS. la, 1b and 1c is obtained, after which the opening is sealed in the manner described with reference to FIGS. la., lb and 1c.

The embodiment'shown in FIGS. la, 1b, 1c and 2 is concerned with a flat, glass envelope and a plate-shaped Itl will be obvious that the invention may also be carried out with other circuit elements, for example semi-conductor devices and other shapes of envelopes and/ or bodies, in which similar problems are brought about by the difference in clearance spaces along the periphery of the body to be embedded. For example a similar problem is involved in using a tubular envelope having a circular section, fitting with a certain amount of play about a rod-shaped body, for example a semi-conductor body having rectangular section and different lengths of the sides, so that the clearance space between one pair of sides and the envelope is unequal to that between the other pair of sides and the envelope. In order to acquire a uniform embedding local extensions are used, which partly fill the place of larger clearance. It will furthermore be obvious that within the scope of the invention many variants are possible to those skilled in the art. The invention may also be applied for example to aconfiguration as shown in FIG; 1, when the cooling plate 8 is omitted and the body to be embedded is formed substantially only by the photosensitive plate. According as the height of the body to be embedded is greater, the greater will be the effectiveness of the invention.

What is claimed is:

1. An electrical device comprising a tubular envelope having an open end, anv electrically-active body containing electrodes disposed within theenvelope and'defning between the periphery of the body'and the inside wall of the envelope an annular clearance space having v a non-uniform cross section, a grease like filling mass disposed in the clearance space and extending at least over the greater part of the length of the body, at least one projection extending from the body into that part of the non-uniform annular clearance space which is greater than adjacent parts of the clearance space to obtain more uniform disposition of the filling mass within the clearance space, means sealing the open end of the envelope, and lead-in conductors passing through the sealing means and connected to the said electrodes.

2. An electrical device comprising an elongated tubular envelope having an open end, an elongated body including a photoconductive element containing electrodes disposed within the envelope and defining between the periphery of the body and the inside wall of the envelope an annular clearance space having a non-uniform cross section, a paste-like mass disposed in the clearance space and extending at least over the greater part of the length of the body, plural spaced projections distrib'- uted along the length of the body and extending from the body into that part of the non-uniform annular clearance space which is greater than adjacent parts of the clearance space to obtain more uniform disposition of the paste-like mass within the clearance space, said elongated body having a substantially greater specific weight than that of the paste-like mass, means sealing-the open end of the envelope, and lead-in conductors passing through the sealing means and connected to the said electrodes.

3. A device as set forth in claim 2 wherein a resinous I nass seals'the open end leaving an empty space adjacent the paste-like mass to provide for its expansion.

4. A device as set forth in claim 3 wherein an expansioncoxnpensation member is embedded in the resinous mass, and the latter is an epoxy resin.

5. A photoconductive device comprising an elongated tubular envelope with a fiattened oval cross section and having an open end, an elongated plate-like body including a photoconductive element containing electrodes disposed within the envelope and defining between the periphery of the body and the inside wall of the envelope a generally oval, annular clearance space having a nonuniform cross section with larger areas along the envelope side walls than along the broader front and rear walls, a grease-like mass disposed in the clearance space and extending over the Whole length of the body, -the open end of said envelope being free of the grease-like mass, plural projections extending from the edges of the body into the larger areas on both sides of the annular clearance space to obtain more uniform disposition of the grease-like mass within the clearance space, a sealing material filling and sealing the open end of the envelope and adhered to the inner walls thereof, and lead-in conductors passing through the sealing material and connected to the said electrodes.

6. A device as set forth in claim 5 wherein the photoconductive element comprises a photoconductive plate, a metal'cooling strip is provided together with means securing together in electrically-insulating relationship said cooling strip and photoconductive plate along the length of the said plate, said body with the cooling strip having a greater specific weight than that of the greaselike mass.

7.- A device as set forth in claim 5 wherein at least two spaced projections are provided along each edge of the plate-like body.

8. A device as set forth in .claim 5 wherein projections are provided atleast at the end of the plate-like body remote from the open end.

9, A photoconductive device 'comprising an elongated tubular envelope of insulating material with a flattened oval cross section and having an open end, an elongated plate-like body including a photoconductive element containing electrodes disposed within the envelope and defining between the periphery of the body and the inside wall of the envelope a generally oval, annular clearance space having a non-uniform cross section with larger areas along the envelope side Walls than along the broader front and rear Walls, a grease-like mass disposed in the clearance space and extending over the Whole length of the body, the open end of said envelope being free of the grease-like mass, metal clamping members extending along and in clamping engagement with both edges of the plate-like body, plural projections extending from the clamping members into the larger areas on bothsides of the annular clearance space to obtain more uniform'disposition of the grease-like mass within the clearance space, a sealing material filling and sealing the open end of the envelope and adhered to the inner walls thereof, and lead-in conductors passing through the sealing material and connected to the said electrodes.

10. A device as set forth in claim 9 wherein the projections constitute punched-out tags of the clamping members.

' 7 11. A device as set forth in claim 9 wherein the projections extend partly toward the sealed end of the envelope.

12. A device as set forth in claim 9 wherein at least some of the projections are spaced from the envelope walls.

References Cited by the Examiner UNITED STATES PATENTS 1,941,493 1/1934 Ruben 25o-212 10 8 Drugrnan 29-15564 Schwing 29-155.64 Haybail et al. 338-18 Anderson 388-18 Karmiggelt et al. 338-15 X ANTHONY BARTIS, Acting Primary Ex'amner. RICHARD M. WOOD, Examiner. I

W. D. BROOKS, H. T. POWELL, Assistant Examiners.

Claims

9. A PHOTOCONDUCTIVE DEVICE COMPRISING AN ELONGATED TUBULAR ENVELOPE OF INSULATING MATERIAL WITH A FLATTENED OVAL CROSS SECTION AND HAVING AN OPEN END, AN ELONGATED PLATE-LIKE BODY INCLUDING A PHOTOCONDUCTIVE ELEMENT CONTAINING ELECTRODES DISPOSED WITHIN THE ENVELOPE AND DEFINING BETWEEN THE PERIPHERY OF THE BODY AND THE INSIDE WALL OF THE ENVELOPE A GENERALLY OVAL, ANNULAR CLEARANCE SPACE HAVING A NON-UNIFORM CROSS SECTION WITH LARGER AREAS ALONG THE ENVELOPE SAIDE WALLS THAN ALONG THE BROADER FRONT AND REAR WALLS, A GREASE-LIKE MASS DISPOSED IN THE CLEARANCE SPACE AND EXTENDING OVER THE WHOLE LENGTH OF THE BODY, THE OPEN END OF SAID ENVELOPE BEING FREE OF THE GREASE-LIKE MASS, METAL CLAMPING MEMBERS EXTENDING ALONG AND IN CLAMPING ENGAGEMENT WITH BOTH EDGES OF THE PLATE-LIKE BODY, PLURAL PROJECTIONS EXTENDING FROM THE CLAMPING MEMBERS INTO THE LARGER AREAS ON BOTH SIDES OF THE ANNULAR CLEARANCE SPACE TO OBTAIN MORE UNIFORM DISPOSITION OF THE GREASE-LIKE MASS WITHIN THE CLEARANCE SPACE, A SEALING MATERIAL FILLING AND SEALING THE OPEN END OF THE ENVELOPE AND ADHERED TO THE INNER WALLS THEREOF, AND LEAD-IN CONDUCTORS PASSING THROUGH THE SEALING MATERIAL AND CONNECTED TO THE SAID ELECTRODES.