GB1577912A - Electrically insulating support bearing a pattern of electrically conductive tracks comprising a heat-sensitive break switch - Google Patents
Electrically insulating support bearing a pattern of electrically conductive tracks comprising a heat-sensitive break switch Download PDFInfo
- Publication number
- GB1577912A GB1577912A GB703/78A GB70378A GB1577912A GB 1577912 A GB1577912 A GB 1577912A GB 703/78 A GB703/78 A GB 703/78A GB 70378 A GB70378 A GB 70378A GB 1577912 A GB1577912 A GB 1577912A
- Authority
- GB
- United Kingdom
- Prior art keywords
- track
- electrically conductive
- tracks
- support
- pattern
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000003973 paint Substances 0.000 claims description 31
- 239000000049 pigment Substances 0.000 claims description 20
- 239000004604 Blowing Agent Substances 0.000 claims description 19
- 239000004071 soot Substances 0.000 claims description 13
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 claims description 6
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 6
- 229920006217 cellulose acetate butyrate Polymers 0.000 claims description 6
- 229920003002 synthetic resin Polymers 0.000 claims description 6
- 239000000057 synthetic resin Substances 0.000 claims description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 5
- IVMYJDGYRUAWML-UHFFFAOYSA-N cobalt(ii) oxide Chemical compound [Co]=O IVMYJDGYRUAWML-UHFFFAOYSA-N 0.000 claims description 5
- 229910002804 graphite Inorganic materials 0.000 claims description 5
- 239000010439 graphite Substances 0.000 claims description 5
- 230000005855 radiation Effects 0.000 claims description 5
- ZNQVEEAIQZEUHB-UHFFFAOYSA-N 2-ethoxyethanol Chemical compound CCOCCO ZNQVEEAIQZEUHB-UHFFFAOYSA-N 0.000 claims description 4
- SVONRAPFKPVNKG-UHFFFAOYSA-N 2-ethoxyethyl acetate Chemical compound CCOCCOC(C)=O SVONRAPFKPVNKG-UHFFFAOYSA-N 0.000 claims description 4
- 239000004020 conductor Substances 0.000 claims description 4
- 238000010521 absorption reaction Methods 0.000 claims description 3
- 239000000463 material Substances 0.000 claims description 3
- 239000002184 metal Substances 0.000 claims description 3
- 229910052751 metal Inorganic materials 0.000 claims description 3
- 239000000126 substance Substances 0.000 claims description 3
- GRRGMQBIAJCOBQ-UHFFFAOYSA-N 4-(thiatriazol-5-yl)morpholine Chemical compound C1COCCN1C1=NN=NS1 GRRGMQBIAJCOBQ-UHFFFAOYSA-N 0.000 claims description 2
- DKPFZGUDAPQIHT-UHFFFAOYSA-N Butyl acetate Natural products CCCCOC(C)=O DKPFZGUDAPQIHT-UHFFFAOYSA-N 0.000 claims description 2
- MRABAEUHTLLEML-UHFFFAOYSA-N Butyl lactate Chemical compound CCCCOC(=O)C(C)O MRABAEUHTLLEML-UHFFFAOYSA-N 0.000 claims description 2
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 2
- 239000001191 butyl (2R)-2-hydroxypropanoate Substances 0.000 claims description 2
- 238000002485 combustion reaction Methods 0.000 claims description 2
- 239000012634 fragment Substances 0.000 claims description 2
- FUZZWVXGSFPDMH-UHFFFAOYSA-N hexanoic acid Chemical compound CCCCCC(O)=O FUZZWVXGSFPDMH-UHFFFAOYSA-N 0.000 claims description 2
- 229920002689 polyvinyl acetate Polymers 0.000 claims description 2
- 239000011118 polyvinyl acetate Substances 0.000 claims description 2
- 238000012216 screening Methods 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 239000000155 melt Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 238000007639 printing Methods 0.000 description 2
- 238000005476 soldering Methods 0.000 description 2
- 239000004156 Azodicarbonamide Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- XOZUGNYVDXMRKW-AATRIKPKSA-N azodicarbonamide Chemical compound NC(=O)\N=N\C(N)=O XOZUGNYVDXMRKW-AATRIKPKSA-N 0.000 description 1
- 235000019399 azodicarbonamide Nutrition 0.000 description 1
- 230000001680 brushing effect Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000003116 impacting effect Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229910000679 solder Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
- H01C7/10—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material voltage responsive, i.e. varistors
- H01C7/12—Overvoltage protection resistors
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B15/00—Special procedures for taking photographs; Apparatus therefor
- G03B15/02—Illuminating scene
- G03B15/03—Combinations of cameras with lighting apparatus; Flash units
- G03B15/04—Combinations of cameras with non-electronic flash apparatus; Non-electronic flash units
- G03B15/0452—Electrical ignition means connected to the shutter
- G03B15/0457—Ignition mechanisms for sequential ignition of flash lamps
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/02—Details
- H05K1/0286—Programmable, customizable or modifiable circuits
- H05K1/0293—Individual printed conductors which are adapted for modification, e.g. fusable or breakable conductors, printed switches
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/02—Details
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
- H05K2201/01—Dielectrics
- H05K2201/0104—Properties and characteristics in general
- H05K2201/0112—Absorbing light, e.g. dielectric layer with carbon filler for laser processing
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
- H05K2201/10—Details of components or other objects attached to or integrated in a printed circuit board
- H05K2201/10007—Types of components
- H05K2201/10181—Fuse
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
- H05K2203/17—Post-manufacturing processes
- H05K2203/175—Configurations of connections suitable for easy deletion, e.g. modifiable circuits or temporary conductors for electroplating; Processes for deleting connections
Landscapes
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Paints Or Removers (AREA)
- Manufacture Of Switches (AREA)
- Insulated Conductors (AREA)
- Elimination Of Static Electricity (AREA)
- Switches Operated By Changes In Physical Conditions (AREA)
- Conductive Materials (AREA)
- Fuses (AREA)
Description
(54) ELECTRICALLY INSULATING SUPPORT BEARING
A PATTERN OF ELECTRICALLY CONDUCTIVE TRACKS
COMPRISING A HEAT-SENSITIVE BREAK SWITCH.
(71) We, N. V. PHILIPS' GLOEILAMPENFABRIEKEN, a limited liability Company, organised and established under the laws of the Kingdom of the
Netherlands, of Emmasingel 29, Eindhoven, the Netherlands do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:
The invention relates to an electrically insulating support bearing a pattern of electrically conductive tracks, in which pattern a track-part of an electrically conductive paint forms a heat-sensitive break switch.
Such a support destined for a flash bulb unit is disclosed in United States Patent
Specification 3,532,931. In this support, the break switch is a silk screened track-part having a locally reduced cross-section which fuses when current passes through it. It is also known from the same Patent Specification that the break switch may alternatively be a thin wire in the pattern, which wire extends across a hole in the support. The drawback of the last-mentioned break switch is that a separate component has to be used which has to be added to the pattern of tracks by a soldering operation. During soldering sufficient heat must be applied to cause the solder to flow, and the wire must be prevented from melting. Therefore the provision of this break switch wire is a critical step in the manufacture of the support.
However, the operation of the break switch is reliable since the wire which forms the break switch does not contact the support over a part of its length so that the wire breaks easily when it melts.
The break switch consisting of a silkscreened track-part can however easily be provided on the support. When the material of this break switch melts, there is no guarantee that the electrical contact will be broken since the track is supported throughout its length by the support. Should the support have a hole somewhere under the area of the break switch, the break switch could no longer be provided by a simple operation such as silk-screening or brushing.
It is the object of the invention to provide an electrically insulating support with a pattern of tracks in which a break switch is incorporated and of which the break switch can both be manufactured in a simple.
manner and is very reliable in operation.
The invention provides an electrically insulating support bearing a pattern of electrically conductive tracks including a track-part of electrically conductive paint, which track-part forms a heat-sensitive break switch, wherein the said electrically conductive paint contains a dark pigment and/or a blowing agent and develops a high electrical resistance on being heated. Blowing agents are used in the manufacture of foamed plastics (see Kirk-Othermer Encyclopedia of Chemical Technology, second edition, 17, 532-533; Ulmann Encyklopädie der technischen Chemic 8 711. 712, and 12 759; Handbuch fir die Gummi-Industrie,
Leverkusen 491-510 (1971). They are monomeric compounds which decompose at elevated temperature while giving off gaseous products, usually nitrogen.
When the break switch of an electrically insulating support bearing electrically con ductive tracks according to the invention comprises a blowing agent, the cohesion of the initially conductive track is interrupted when the blowing agent decomposes as a result of a rise in temperature, since the gas bubbles which are evolved in the track, force the conductive particles apart and cause this track-part to have a very high resistance. In order to interrupt the electric circuit, it is therefore not necessary in said break switch for the track to melt and for the melt to subsequently contract.
It is of no significance for the operation of the break switch whether a rise in temperature occurs as a result of current passage or as a result of light and/or thermal irradiation. If the break switch is to be activated by irradiation, its operation can be accelerated by incorporating in it a dark pigment, for example 0.5-1% by weight calculated on the solid constitutents of the electrically conductive paint, so as to increase its radiationabsorbing capacity.
It has surprisingly been found that the same effect is obtained when the break switch comprises a dark pigment instead of a blowing agent and the break switch is exposed to light or thermal radiation. The mechanism by which a very high resistance occurs at the area of the break switch when it is irradiated is not yet understood.
However, the track-part is significantly damaged and presents a wrinkled and withered appearance.
If desired, a dye may be incorporated in the paint as an indicator which in the case of a rise in temperature irreversibly changes in colour.
The electrically insulating supports according to the invention may be used in various apparata, in particular in flash bulb units.
The pattern of tracks may be formed on the support by additive or by subtractive processes. It may consist of a metal layer or of an electrically conductive paint. The advantage of conductive paint is that it can be provided rapidly by means of printing methods. The break switches can also be provided by means of printing methods, for example silk screening, with a brush or by spraying.
It has been found possible to provide tracks across narrow gaps in the support without there being a break in electrical contact between the track parts on opposite sides of the gap. It has been found that gaps up to three tenths of a millimetre, for example 0.1 to 0.2 mm, can be bridged.
Although the provision of gaps in the support is not necessary for the reliable operation of break switches, it may nevertheless have advantages.
For some applications it is desirable that an electrically insulating support with a pattern of tracks in which heat-sensitive break switches are incorporated, should also present the possibility of interrupting contacts mechanically. If the support is locally weakened, it will be easier to break away a part of the support and hence interrupt a track, for example, by impacting with a pointed object.
When a track-part containing a blowing agent and/or a dark pigment is guided across a gap in the support, there is the possibility of integrating a mechanical and heatsensitive break switch.
The possibility of manufacturing the whole pattern of tracks including the break switches from an electrically conductive paint containing a blowing agent and/or a dark pigment is very attractive for production engineering. Dependent on the application of the product, the pattern of tracks may be screened, except in one or more places, from a radiation source and a rise in temperature in the non-screened place(s) is thus possible, or no screening may be provided so as to allow the tracks to be interrupted over a larger area. It is possible, however, that a source of radiation has such a small capacity that only a track-part in the immediate proximity of the source is destroyed.
In many cases, for example in a flash bulb unit having several flash bulbs, it will be desired that only one contact is interrupted each time a bulb is fired. In those cases the reflector which often is present for the greater part between the bulbs and the electrically insulating support bearing the pattern of tracks, may serve as a screening, if screening is desired at all. A track-part situated near the fired bulb can be irradiated and heated via an aperture in the reflector.
When an electrically insulating support bearing electrically conducting tracks according to the invention having a break switch comprising a blowing agent is used in a flash bulb unit, the blowing agent used will generally be operative in the temperature range of 80-250"C, in particular in the range of 100-200"C. As a rule, 10-20% by weight of blowing agent will be added to the paint, calculated on the dry constituents of the paint.
As examples of blowing agents may be mentioned: azoisobutyronitrile (decomposition temperature 100"C); diphenysulphone3,3'-disulphonyl-hydrazide (155 C), 5- morpholyl-1,2,3,4-thiatnazole (115 C); azodicarbonamide (210"C).
The quantity of dark pigment which is used in conductive paint in places where a track-part formed with said paint is to serve as a break switch, is associated with the absorption coefficient of the pigment. When a black pigment is used, for example soot, graphite or cobalt black, a low percentage will generally suffice. When used in combustion flash bulb units, up to 4% by weight calculated on the dry material will suffice.
When another dark pigment is used, the absorption coefficient of the track-part containing said pigment serving as a break switch will generally be at least 0.85.
Due to the very small quantities required and due to the smaller increase in resistance which they consequently give to the paint, black pigments such as soot, graphite and cobalt black are to be preferred.
Examples of electrically conductive paints with blowing agent and/or pigment are: a) 4 g methyl methacrylate
12 g cellulose acetate butyrate
150 g nickel powder
25 g diphenylsulphone-3,3' disulphonehydrazide.
b) 16 g polyvinyl acetate
50 g silver powder
35 g butyl lactate
5 g butyl acetate
10 g 5-morpholyl-1,2,3,4-thiatriazole c) 24 g methyl methacrylate
630 g ethyl glycol acetate/ethyl glycol (80/20 vol/vol)
1800 g nickel powder
72 g cellulose acetate butyrate
190 g 5 morpholyl-1,2,3,4-thiatriazole
15 g soot.
d) 27 g of methyl methacrylate
72 g of cellulose acetate butyrate
1800 g of nickel powder
630 g of ethyl glycol acetate/ethyl glycol (80/20 vol/vol)
45 g of soot e) as d) but with 60 g of cobalt black instead of soot f) as d) but with 54 g of graphite instead of soot.
Some embodiments of supports according to the invention will now be described with reference to the accompaying drawing, in which:
Figure 1 is a partly perspective view of part of a support according to the invention.
Figure 2 is a longitudinal sectional view through a flash bulb unit in which a support according to the invention is used, and
Figure 3 is a plan view of a fragment of a support.
Reference numeral 1 in Figure 1 denotes a synthetic resin support on which metal tracks 2, 3 and 4 are provided. 5 denotes a break switch which consists of a track-part of electrically conductive paint containing a blowing agent. The broken line 6 denotes the circumference of a flash bulb which has current supply conductors 7 and 8 which are connected to tracks 3 and 4, respectively.
When the flash bulb is fired by applying a voltage across the tracks 2 and 4, the electrical contact in track-part 5 is interrupted.
In Figure 2, a synthetic resin support 1 is incorporated in a synthetic resin housing 10 which is closed with a transparent cover 11.
A reflector 12 is present between the support 1 and the cover 11. Flash-bulbs 6 are provided between the reflector 12 and the cover 11. At the level of the flash-bulbs 6, each reflector 12 has an aperture 13. The support 1 is provided with a pattern of electrically conductive tracks which consist entirely of electrically conductive paint containing a blowing agent. The track-parts serving as break switches are denoted by 5.
When the first bulb is fired by applying a voltage across track 4 and track 2 (not shown), the electrical contact in the trackpart 5 situated behind said aperture 13 is interrupted via aperture 13 in the part of the reflector 12 associated with the bulb without the conductivity in the remaining parts of the pattern of tracks being lost.
In Figure 3, a transparent electrically insulating support 1 is provided on its front with conductive tracks 2 and 3 and a track-part 5 of electrically conductive paint containing soot. The track-part 5 extends across a gap 20 which has widenings 21 on each side of said track-part 5. As a result of the presence of the gap 20 and the widenings 21, a considerable part of the support 1 which is situated below the track-part 5 can easily be removed mechanically. In this case, the radiation source may also be accommodated on the rear side.
The resistance between each of the conductors of a flash lamp ready to be flashed attached to the circuit pattern and the points where a voltage source is connected to the circuit pattern should be, for example not more than 5 x 103 ohms. When the circuit pattern consists as a whole of the substance functioning locally as a break switch, this requirement implies a specific resistance of not more than 104 ohms/mm3 and preferably not more than 103 ohms/mm3.
WHAT WE CLAIM IS:
1. An electrically insulating support bearing a pattern of electrically conductive tracks including a track-part of electrically conductive paint, which track-part forms a heat-sensitive break switch, wherein the said electrically conductive paint contains a dark pigment and/or a blowing agent and develops a high electrical resistance on being heated.
2. An electrically insulating support as claimed in Claim 1, wherein all tracks of the pattern consist of the said electrically conductive paint.
3. An electrically insulating support as claimed in Claim 1 or Claim 2, wherein the electrically conductive paint contains a black pigment.
4. An electrically insulating support bearing a pattern of electrically conductive
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (1)
- **WARNING** start of CLMS field may overlap end of DESC **.will generally suffice. When used in combustion flash bulb units, up to 4% by weight calculated on the dry material will suffice.When another dark pigment is used, the absorption coefficient of the track-part containing said pigment serving as a break switch will generally be at least 0.85.Due to the very small quantities required and due to the smaller increase in resistance which they consequently give to the paint, black pigments such as soot, graphite and cobalt black are to be preferred.Examples of electrically conductive paints with blowing agent and/or pigment are: a) 4 g methyl methacrylate12 g cellulose acetate butyrate150 g nickel powder25 g diphenylsulphone-3,3' disulphonehydrazide.b) 16 g polyvinyl acetate50 g silver powder35 g butyl lactate5 g butyl acetate10 g 5-morpholyl-1,2,3,4-thiatriazole c) 24 g methyl methacrylate630 g ethyl glycol acetate/ethyl glycol (80/20 vol/vol)1800 g nickel powder72 g cellulose acetate butyrate190 g 5 morpholyl-1,2,3,4-thiatriazole15 g soot.d) 27 g of methyl methacrylate72 g of cellulose acetate butyrate1800 g of nickel powder630 g of ethyl glycol acetate/ethyl glycol (80/20 vol/vol)45 g of soot e) as d) but with 60 g of cobalt black instead of soot f) as d) but with 54 g of graphite instead of soot.Some embodiments of supports according to the invention will now be described with reference to the accompaying drawing, in which: Figure 1 is a partly perspective view of part of a support according to the invention.Figure 2 is a longitudinal sectional view through a flash bulb unit in which a support according to the invention is used, and Figure 3 is a plan view of a fragment of a support.Reference numeral 1 in Figure 1 denotes a synthetic resin support on which metal tracks 2, 3 and 4 are provided. 5 denotes a break switch which consists of a track-part of electrically conductive paint containing a blowing agent. The broken line 6 denotes the circumference of a flash bulb which has current supply conductors 7 and 8 which are connected to tracks 3 and 4, respectively.When the flash bulb is fired by applying a voltage across the tracks 2 and 4, the electrical contact in track-part 5 is interrupted.In Figure 2, a synthetic resin support 1 is incorporated in a synthetic resin housing 10 which is closed with a transparent cover 11.A reflector 12 is present between the support 1 and the cover 11. Flash-bulbs 6 are provided between the reflector 12 and the cover 11. At the level of the flash-bulbs 6, each reflector 12 has an aperture 13. The support 1 is provided with a pattern of electrically conductive tracks which consist entirely of electrically conductive paint containing a blowing agent. The track-parts serving as break switches are denoted by 5.When the first bulb is fired by applying a voltage across track 4 and track 2 (not shown), the electrical contact in the trackpart 5 situated behind said aperture 13 is interrupted via aperture 13 in the part of the reflector 12 associated with the bulb without the conductivity in the remaining parts of the pattern of tracks being lost.In Figure 3, a transparent electrically insulating support 1 is provided on its front with conductive tracks 2 and 3 and a track-part 5 of electrically conductive paint containing soot. The track-part 5 extends across a gap 20 which has widenings 21 on each side of said track-part 5. As a result of the presence of the gap 20 and the widenings 21, a considerable part of the support 1 which is situated below the track-part 5 can easily be removed mechanically. In this case, the radiation source may also be accommodated on the rear side.The resistance between each of the conductors of a flash lamp ready to be flashed attached to the circuit pattern and the points where a voltage source is connected to the circuit pattern should be, for example not more than 5 x 103 ohms. When the circuit pattern consists as a whole of the substance functioning locally as a break switch, this requirement implies a specific resistance of not more than 104 ohms/mm3 and preferably not more than 103 ohms/mm3.WHAT WE CLAIM IS: 1. An electrically insulating support bearing a pattern of electrically conductive tracks including a track-part of electrically conductive paint, which track-part forms a heat-sensitive break switch, wherein the said electrically conductive paint contains a dark pigment and/or a blowing agent and develops a high electrical resistance on being heated.2. An electrically insulating support as claimed in Claim 1, wherein all tracks of the pattern consist of the said electrically conductive paint.3. An electrically insulating support as claimed in Claim 1 or Claim 2, wherein the electrically conductive paint contains a black pigment.4. An electrically insulating support bearing a pattern of electrically conductivetracks, including a track-part of electrically conducting paint, which track-part forms a heat-sensitive break switch, substantially as herein described with reference to Figure 1 or Figure 3 of the accompanying drawings.5. A flash bulb unit including an electrically insulating support as claimed in any of Claims 1 to 4.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL7700231A NL7700231A (en) | 1977-01-12 | 1977-01-12 | Flash bulb support with electroconducting paint connections - has conducting paint strip which is interrupted when flash bulb is illuminated |
| NL7711774A NL7711774A (en) | 1977-10-27 | 1977-10-27 | Flash bulb support with electroconducting paint connections - has conducting paint strip which is interrupted when flash bulb is illuminated |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1577912A true GB1577912A (en) | 1980-10-29 |
Family
ID=26645274
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB703/78A Expired GB1577912A (en) | 1977-01-12 | 1978-01-09 | Electrically insulating support bearing a pattern of electrically conductive tracks comprising a heat-sensitive break switch |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS5388193A (en) |
| DE (1) | DE2800102A1 (en) |
| FR (1) | FR2377744A1 (en) |
| GB (1) | GB1577912A (en) |
| IT (1) | IT1091830B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2202698A (en) * | 1987-03-24 | 1988-09-28 | Coopers Ind Inc | Microfuse |
| US6479763B1 (en) | 1998-08-28 | 2002-11-12 | Matsushita Electric Industrial Co., Ltd. | Conductive paste, conductive structure using the same, electronic part, module, circuit board, method for electrical connection, method for manufacturing circuit board, and method for manufacturing ceramic electronic part |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3409190B2 (en) * | 1993-06-17 | 2003-05-26 | ソニーケミカル株式会社 | Fuse resistor |
| JP2017011253A (en) * | 2015-06-24 | 2017-01-12 | 住友電工プリントサーキット株式会社 | Flexible printed wiring board |
-
1978
- 1978-01-03 DE DE19782800102 patent/DE2800102A1/en active Pending
- 1978-01-06 IT IT19096/78A patent/IT1091830B/en active
- 1978-01-09 GB GB703/78A patent/GB1577912A/en not_active Expired
- 1978-01-09 JP JP61278A patent/JPS5388193A/en active Pending
- 1978-01-10 FR FR7800512A patent/FR2377744A1/en not_active Withdrawn
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2202698A (en) * | 1987-03-24 | 1988-09-28 | Coopers Ind Inc | Microfuse |
| GB2202698B (en) * | 1987-03-24 | 1991-12-11 | Coopers Ind Inc | Microfuse and method of manufacture |
| US6479763B1 (en) | 1998-08-28 | 2002-11-12 | Matsushita Electric Industrial Co., Ltd. | Conductive paste, conductive structure using the same, electronic part, module, circuit board, method for electrical connection, method for manufacturing circuit board, and method for manufacturing ceramic electronic part |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5388193A (en) | 1978-08-03 |
| FR2377744A1 (en) | 1978-08-11 |
| IT1091830B (en) | 1985-07-06 |
| DE2800102A1 (en) | 1978-07-20 |
| IT7819096A0 (en) | 1978-01-06 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed [section 19, patents act 1949] | ||
| PCNP | Patent ceased through non-payment of renewal fee |