Improvements in and relating to radiation-sensitive semiconductor devices
8 claims: 4 independent, 4 dependent
- 1Patentkrav 1. Anordning för omvandling av strålning till elektrisk energi, innefattande ett batteri av strålningskänsliga halvledarelement som äro elektriskt hopkopplade och anordnade på en flexibel bärare, kännetecknad därav, att bäraren bildas av en flexibel platta av elektriskt isolerande material, som är försedd på åtminstone en sida med metalliserade ytdelar försedda med inskärningar över tjockleken hos plattan, varigenom tungor bildas, vilka är så uppböjda, att deras ursprungligen från halvledarelementen vända, metalliserade ytor kommer i kontakt med nämnda element åtminstone på dessas från plattan vända sida, varigenom den elektriska hopkopplingen av de strålningskänsliga elementen och deras mekaniska fixering på bäraren erhålles åtminstone delvis genom tungorna och de metalliserade ytdelama.
- 2Anordning enligt patentkravet 1, kännetecknad därav, att de strålningskänsliga elementen innefatta en halvledarplatta som på båda sidor är försedd med ett elektrodskikt.
- 3Anordning enligt patentkravet 2, kännetecknad därav, att bäraren innefattar endast på en sida metalliserade ytdelar och åtminstone två mittemot belägna tungor samordnade med närliggande metalliserade ytdelar, varvid en av tungorna är omböjd så, att dess isolerande yta är belägen mittemot den isolerande ytan hos bäraren och den metalliserade ytan hos tungan är i beröring med ett av elektrodskikten hos ett strålningskänsligt element, medan den andra tungan är i beröring genom sin metalliserade yta med det andra elektrodskiktet hos nämnda element.
- 4Anordning enligt patentkravet 2, kännete cknad därav, att bäraren på ena sidan är försedd med en första grupp av metalliserade ytdelar i vilka tungor äro utskurna, medan mittemot var och en av ytdelama på den andra sidan av bäraren en mindre metalliserad ytdel är samordnad med en andra grupp, vilken del är galvaniskt förbunden med den motsatt belägna metalliserade ytdelen i den första gruppen t,ex. medelst ett metalliserat hål, varvid varje strålningskänsligt element är i beröring genom sina elektrodskikt med en tunga samordnad med den första gruppen och genom det andra elektrodskiktet med en metalliserad ytdel i den andra gruppen som ej är galvaniskt förbunden med nämnda tunga.
- 5Anordning enligt något av de föregående patentkraven, kännetecknad därav, att den flexibla bäraren består av en polyimidharts.
- 6Anordning enligt något av de föregående patentkfaven, kännetecknad därav, att de metalliserade ytdelama äro försedda med ett metallskikt som består av silver, åtminstone på den yta som är vänd från bäraren.
- 7Anordning enligt något av de föregående patentkraven, kännetecknad därav, att de strålningskänsliga elementen äro anordnade i rader och äro hopkopplade i serie i en rad. 333378
- 8Anordning enligt patentkravet 7, kännetecknad därav, att två eller flera rader äro hopkopplade parallellt med varandra.
Independent claims8
57 paragraphs in 2 sections, as filed
SWEDEN
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PATENTS AND REGISTRATION OFFICE
PUBLISHING WRITING No. 338 378 mtc. H 01 1 15/02 Kl. 21 g 29/10
Patent Application. No. 15344/68 Received 12 XI 1968 Validity Date 12 XI 1968
Ans. generally available on 16 V 1969
Ans. published and the pamphlet published on β ιχ -J971
Priority requested from 15 XI 196?
(France, 128,265)
ΪΠΓ PHILIPS * GLOEILÅMEEN FACTORY, EINDHOVEN, NETHERLANDS
Inventor J Lebrun, Paris, France
Representative: S Åkesson
Apparatus for converting radiation to electrical energy, comprising a battery of radiation-sensitive semiconductor elements, which are electrically coupled and arranged on a flexible carrier
The present invention relates to a device for converting radiant energy to electrical energy comprising a battery of radiation sensitive semiconductor elements which are electrically interconnected and arranged on a flexible carrier.
Radiation sensitive devices of the aforementioned kind are known and can be used for detecting radiation energy or for generating electrical power through the conversion of radiation energy. The radiation may be electromagnetic radiation or corpuscular radiation.
The invention is particularly important for space research. It is known that the electrical energy required to operate the various instruments in satellites and other spacecraft is largely supplied by solar batteries. These batteries are in the form of flat or curved panels, on which many hundreds of solar cells are arranged close to one another in a regular pattern, the cells being electrically connected in series or in parallel to achieve the desired voltages and current densities.
For this use of solar batteries in spacecraft, it is especially important to have panels available with high mechanical flexibility, whereby they can be arranged in said vessels so that they are adapted to the
333378 the outer profile, while they occupy a small volume and surface during the periods when they are not used, for example, during the launch of a satellite or before it enters its canopy, whereby the panels can be developed into a large area at the desired moment.
The requirement for high flexibility of the panel also depends on the need for each such solar battery to obtain a mechanical independent of nearby batteries, thereby avoiding the formation of mechanical stress zones in the panel due to heat shocks generated by the successive transmissions of the panel from a solar zone to a dark zone and vice versa and due to the vibrations generated during the launch, which mechanical stresses can cause breakage or at least serious injury.
The known technique by which solar batteries with rigid panels with sufficient flexibility can be obtained for adaptation to curved profiles or small radii of curvature is obtained by connecting the batteries by means of ribs or thin metal bands which are suitably fixed by soldering to the rear surface of a battery and the edges of the front surface of the adjacent battery. Due to the natural flexibility of ribs or bands and if the carrier is made of flexible material, the panels can be deformed to a limited degree.
This technique is used in the method of interconnecting solar batteries as described in French patent 1,424,414. In order to achieve maximum flexibility of the panel combined with a satisfactory mechanical resistance of the solder joints, the interconnecting elements described in said patent are formed by a perforated metal band forming a grating. with a thickness of about 0.05 mm. The solar batteries interconnected by said grid are then attached to a carrier formed by an insulated metal sheet by means of a silicon rubber adhesive or directly onto a substrate of said adhesive. The resulting panels can be rolled independently of each other.
The production of such units requires considerable expertise and a long time.
It is necessary to first connect the various batteries by means of ribs or metal grilles. Thereafter, the resulting matrix must be attached to an outer support. The metal connection band, especially the lattice, is very fragile. The matrix of batteries must be manipulated very carefully as long as it is not fixed on an external carrier. Accordingly, the manufacture of solar battery panels is particularly difficult due to the work and the fragility of the components.
The present invention eliminates these disadvantages. It allows the construction of units in which each solar battery has an increased mechanical independence relative to nearby batteries, whereby the unit has a greater resistance to heat shock and vibration. The invention further allows a reduction of the weight of the units by minimizing the cross-sectional areas of the electrical connections between the batteries, while each connection has a larger contact surface.
:·· :-:</ 338378
A device of the above type according to the invention is characterized in that the support is formed of a flexible plate of electrically insulating material, which is provided on at least one side with metallized surface parts provided with cuts over the thickness of the plate, whereby tongues are formed which are so bent that their metallized surfaces originally turned away from the semiconductor elements come into contact with said element at least on their side facing away from the plate; whereby the electrical interconnection of the radiation-sensitive elements and their mechanical fixation on the support is obtained at least in part by the tongues and the metallized surface parts.
The flexible support forming the substrate of the panel is made from an insulating flexible material with physical, chemical and mechanical properties that can withstand practically a temperature range of -70 ° C to + 70 ° C. Particularly suitable are polyimide resins of the type described in U.S. Pat. Patent No. 3,179,634 has been found. A suitable polyurea resin under the trade name "Kapton" is sold by Dupont de Nemours. This material remains flexible and resistant and retains its other properties between -200 ° C and + 300 ° C.
In a first suitable embodiment, the radiation-sensitive elements comprise a semiconductor plate provided on either side with an electrode layer.
Another important embodiment is characterized in that the carrier comprises on one side metallized surface parts and at least two oppositely positioned tongues co-ordinated with adjacent metallized surface parts, one of the tongues being folded so that its insulating surface is opposite the insulating surface of the support, while its metallized surface is in contact with one of the electrode layers of a radiation sensitive element, and the second tab is in contact with the second electrode layer of the radiation-sensitive element through its metallized surface.
In another suitable embodiment of the invention, the device is characterized in that the carrier comprises, on one side, a first group of metallized surface parts, in which tongues have been formed by notches, while opposite each of these surface parts on the other side of the carrier a less metallized surface part. arranged with a second group, which part is galvanically connected to the opposite metallized surface part of the first group, for example by means of a metallized hole, while by one of its electrode layers, each radiation-sensitive element is in contact with a tongue in the first group and through the second electrode layer with a metallized surface part in the second group, which part is not galvanically connected to said tongue.
In order to obtain a suhstrat panel for the radiation sensitive elements of the invention, the conductor may be covered with a film of a few microns thickness of a metal such as copper or silver on one or both sides, depending on the particular desired characteristic grid for the connection network. This
333378 can be effected by known methods by steam precipitation in vacuo on the entire conductor, the parts to be eliminated being subsequently etched or removed by a selective mask. It should be noted that the production of a solar panel can be simplified by the use of commercially available plastic carriers provided with metal coatings. The above mentioned Kapton can e.g. is obtained in the form of plates solidified on one or both surfaces with a copper layer. It is also possible to form the connection network by zones and laminations of thin metal plates (thickness approx. 15 yu) provided on a surface with a cold resin polymerizing and retaining the elements on the plastic carrier. Such automatically adhering tiles are found in general trade.
In a second step of the manufacture of the solar panel according to the invention, the carrier is cut along a series of lines defining the periphery or inside of the metal surface portions which previously formed the connecting tongues, which can be folded onto the conductor.
The electrical connection between the electrodes in the elements and the metal surface parts is made according to the invention by a suitable eutectic, e.g. an alloy of lead, tin and antimony which is caused to melt by heating the support to a temperature of about 90 ° C, while the radiation-sensitive elements are heated for a few seconds to about 200 ° C at least on the side which is turn from carrier.
In order to connect the batteries in parallel, it is sufficient that between the metal zones in which the connecting tongues are cut, laminations of different widths are provided depending on the value of the current to pass through the elements in question.
An important advantage of the method according to the invention for producing a panel of solar batteries consists in the semi-mechanization of the preparation, which has heretofore been a manual process. The part of the process which relates to the preparation of the conductor, ie metallization and cutting of the connecting tongues, can be done quickly by industrial processes. Thus, the workmanship is limited to the arrangement of the batteries on the carrier and the appropriate distribution of the tongues. However, this operation is much easier than first making a matrix by means of ribs or metal hand and then attaching the matrix to a carrier. Since the connection network is initially in common with the conductor, it need not have any natural mechanical resistance, as is the case with ribs or grilles. It is therefore possible to construct said grid on the basis of its electrical function. This results in a weight saving, which is not great, but still valuable for those cases where minimum weight is crucial.
A further advantage lies in the fact that the batteries are mechanically hooked only through the plastic carrier, whereas from a mechanical point of view the connections obtained by printed wiring are negligible. Thus, the influence of heat shock and vibration on the panel's life is reduced to a minimum, especially as the mechanical properties of the support are only slightly affected by large temperature variations.
The connections between the elements introduce no mechanical resistance and the resulting panel can be easily folded. It is sufficient to achieve such a distribution of the elements that folding zones of sufficient width are left behind. whereby no tensile stresses are exerted on the connecting tongues, which could otherwise damage the elements. By providing suitable free zones between the elements, the panel can be easily rolled.
Finally, an element that has been damaged during assembly can be easily replaced according to the invention. Since each element is mechanically independent of one another, it is sufficient to remove the erroneous element in the connecting tongues in question and to redeem another element.
The invention further relates to a carrier suitable for use in a device according to the invention. Instead of solar batteries, e.g. radiation detectors in the form of photo resistors or other radiation sensitive elements are arranged on such a carrier.
The invention is described in greater detail below with reference to the accompanying drawing, which shows a panel intended to accommodate six radiation-sensitive elements, which elements are connected in two series with three elements arranged in parallel. It is clear that the number of elements can be considerably larger and that they can be mounted in other ways.
Fig. 1 is a top plan view of a flexible carrier coated with metal zones for interconnection of the radiation-sensitive elements.
Fig. 2 shows a cross-section taken along line II-II in Fig. 1 through carriers in Fig. 1.
Fig. 3 is a top view of the wearer after cutting out the connecting tongues.
Fig. 4 shows a cross section taken along line IV-IV in Fig. 3.
Figures 5 and 6 show a top view and in a cross-section taken along the line VI-VI the panel according to the invention before the arrangement of the elements.
Fig. 7 shows on an enlarged scale a special part of the panel according to Figs. 5 and 6, in which a radiation-sensitive element is arranged.
Figures 8,9 and 10 show in one variant of the invention the use of tongues cut from the support body and metallized holes as connecting means.
The flexible carrier 10 in Figures 1 and 2 is made of insulating plastic material which is provided on a surface with several separate metal zones 11,12,13,14,15 and 16, for example, with rectangular shape, the thickness of which can vary between one and several tens of microns as needed.
These zones may be provided with a layer of a metal or several layers arranged one on the other. The upper layer, that is, the layer which is furthest away from the carrier, is preferably made up of silver which is precipitated from the vapor phase in vacuo. In the embodiment shown in said figures, zones 12-15 form a pattern of lines and gaps, while zones 11 and 16 are located on each side of said pattern, whereby their shreds are at least equal to the shreds of the pattern.
The resulting carrier 10 is cut along a series of lines 17 (the width of which is shown to be greatly exaggerated in Figs. 3 and 4), thereby releasing at the peripheries of said metal zones tongues such as 11a, 12a and 12b, 14a and 14b, 16a, whereby the positions are such that each of these is located opposite another connected to a further zone. These tongues released from the carrier 10 have a given freedom of movement relative to the carrier, whereby they can be used as electrical connection elements for the radiation-sensitive elements with which the carrier is to be equipped. For this purpose, the tongues 11a, 12b and 14b are backward folded so that their insulating surface is in contact with the uncoated, insulated surface, the carrier 10. The tongues 12a, 14a and 16a are bent only in a direction towards said uncoated surface (see Fig. 5 and 6). This also applies to the tongues not indicated in the figures and which are cut out of zones 13 and 15.
Between two opposite tongues coordinated with different metal zones, for example tongues 12b and 14a (see Figs. 6 and 7), a radiation sensitive element 18 is connected. The rear surface of the element 18 which is coated in a known manner with a conductive layer, e.g. of silver, is brought into contact with part of its surface with the metallic part ay the raised tongue 12b, while the tongue 12a is hook weighted to the collector arranged on the edge of the front surface of the element 18. Solder lamination of an alloy of lead, tin and antimony has previously been arranged on the contact surface to provide suitable mechanical and electrical connections after melting of the alloy. A small precipitation 19 of a suitable adhesive results in a sufficient mechanical stiffness of the unit during the conduction process. When all radiation-sensitive elements have been arranged on the panel, soldering takes place by preheating the panel to about 90 ° C, for example by placed on a heated surface and by means of a metal plate heated to a temperature of about 200 ° C is applied directly to the elements, causing the alloy to melt. This operation takes 2 to 3 seconds per element or per group of elements.
In the embodiment shown in the preceding figures, six elements can be distributed at the different locations arranged on the carrier 10, and they can be connected by the different metal zones, while zones 11 and 16 form the input and output electrodes of the device. The latter zones include tongues opposite zones 12,13 and 14,15. In this way, two series of three elements coupled parallel to their ends are obtained. If it is desired to achieve parallel connections with levels which lie between said ends, it is sufficient, for example, to connect zones 12 and 13 on the one hand and 14 and 15 on the other by metal laminations which must be provided when the electrical connection network is arranged.
For the sake of simplicity, the metal zones 11,12,13,14,15 and 16 are shown in regular geometric form. Obviously, a more precise construction of said zones can provide zone parts which do not cover the connecting tongues, a smaller area corresponding to the low currents passing through them.
The flexible carrier 20 shown in Figs. 8 to 10 for accommodating six radiation sensitive elements comprises metal zones deposited on each of its surfaces. These metal zones have been shown in detail in Fig. 9, which shows a cross-section taken along line IX-IX in Fig. 8. From left to right in the figure, the upper surface of the carrier 20 shows in the order zones 22,23,24 and the lower one. the surface of said carrier has zones 25,26,27 and 28 corresponding to the previous zones but has a larger surface. The unit with these zones was used to connect an initial series of three elements. Equivalent precipitates not indicated in the figure are arranged in parallel with the former for connection of a second series of three elements.
The zones 25 and 28 at the end terminals are single zones and connected to the two series set forth above for zones 11 and 16. Zones 22 and 25, 23 and 26, 24 and 27 are paired in pairs by metallized holes 29 provided by prior art printed art. wiring. The support 29 provided with the various zones interconnected by the metallized holes 29 is formed opposite the zones 25,26 and 27 to form a connecting tongue 30 at the periphery of each of the zones 26,27 and 28.
Radiation sensitive elements 31 are then deposited on the carrier 20 and interconnected in the manner shown on an enlarged scale in Fig. 10. The rear surface of an element 31 is contacted e.g. with the metal zones23 via a solder film (not shown), while one of the tongues 30, i.e. the tuna cut out of the metal zone 27, is brought into contact with the collector of the element arranged at one of the edges of the front surface of the element. An adhesive 32 permits mechanical fixation of the element 31 prior to soldering, which occurs in the same manner as described in the embodiment of a panel as above. Also the tongue 30 cut out of the zone 26 is in contact with the element 31 in connection with the zone 22.
This method of interconnecting by metallized holes which requires further treatment of the carriers allows the avoidance of backward folding of the tongues, which operation may give rise to some difficulties in the case of a very thick carrier.
Of course, by using other equivalent technical components, several variants can be constructed within the scope of the invention.
Contents2
3 sheets
Sheet 1 Sheet 2 Sheet 3
Every citation, both ways
| Document | Relation | Office | Cited during |
|---|---|---|---|
| CN109216490A | Cited by | China | Search report |
10 members in 9 offices
Priority claims1
| Document | Office | Kind | Date |
|---|---|---|---|
| 128265 | France | A |
Members10
| Document | Office | Kind | |
|---|---|---|---|
| FR1552078A | France | A | |
| BE723804A | Belgium | A | |
| NL6816001A | Netherlands (Kingdom of the) | A | |
| DE1807818A1 | Germany | A1 | |
| ES360195A1 | Spain | A1 | |
| JPS4536057B1 | Japan | B1 | |
| US3553030A | United States of America | A | |
| SE338378BThis record | Sweden | B | |
| GB1246837A | United Kingdom | A | |
| DE1807818B2 | Germany | B2 |
Numbers
- Application
- 1534468
Classification
- CPC, 2
- H10F19/904
- Y02E10/50
- IPC, 1
- H01L31 05
