DE2214917A1 - Partial metal foil removal from capacitor foil - by passing current across wetted printing roller - Google Patents

Abstract

Defined zones of the metal coating are removed from a capacitor foil by contacting the foil with the raised parts of a printing roller with raised parts which are kept wetted with water. One pole of a voltage source is applied to the coating and the other to the printing roller. The resulting current destroys the coating in the contacted areas.

Description

Method for removing limited zones of the metal coverings with Insulating material layer provided with metal coverings, in particular a capacitor film The present invention relates to a method of delimited zone removal the metal coverings an insulating material layer provided with metal coverings, in particular a capacitor foil for electrical capacitors.

Such a method is known from DAS 1 150 453.

Metal coverings become place by chemical action of an appropriate Solution destroyed in certain places. One of these procedures requires it the relatively concentrated solution of corrosive salts after adding the appropriate Wash areas clean and then the dielectric is too dry. This requires a relatively high expenditure in terms of equipment and time.

Furthermore, various methods are known, zones from coverings Sand off or wipe off after softening.

In such methods, grinding or wiping disks must be relatively are often replaced, as they are smeared by abrasion and therefore unusable earth. In addition, due to the abrasion alone, the The width of the cover-free zones that can be produced is limited at the bottom.

The object of the present invention is, in particular in the continuous process from metal coverings, which are sufugt on layers of insulating material limited zones of any shape and width can be removed with little effort. These In a method, the task is as stated at the beginning Art solved in that the zones to be removed of the metal coverings with approximately pure water, the respective coverings with one and electrodes with the water comes into contact with the other pole of a voltage source electrically be conductively connected and that after the destruction of the respective Deposits in the areas of wetting the water is removed.

The inventive method has the advantage that washing the Insulating layer after the treatment according to the invention can be dispensed with, since usually and especially with thin coverings that can be regenerated, only a few decomposition products arise, which in addition neither decompose the metal coating nor the layer of insulating material could. So it is sufficient to remove the water after the destruction of the eye without connecting a washing process.

The process is particularly beneficial for metal coverings made of aluminum as these form non-conductive aluminum oxide. As almost pure Water can advantageously be used ordinary tap water. For special critical cases, e.g. recommends the production of very narrow demetallized zones the use of distilled water. A slightly higher voltage must be used here can be used because the resistivity of distilled water is higher. Interferes with the higher voltage and is tap water due to the composition of the Salts contained in it are not suitable, so can distilled water with a use a small amount of acid or base. This is particularly suitable good ammonia, because it is volatile, so it can evaporate with the water.

An easy way to remove the water is to blow it off or sucking off the water. When using distilled water or with Water mixed with ammonia is recommended to use heat for the purpose Removal of the water, since no salts whatsoever on the remaining parts of the covering to be brought.

An electrode is expediently used to carry out the said Process designed so that by the contact with the water electrode the water is also supplied. For this purpose, an electrode in the form of an -R: 'ear is recommended or in a form similar to a ballpoint pen - with an oil transfer ball. For etching at high speed it is recommended that the one with the water The electrode in contact is a rotary printing cylinder on which the deposit is free Zones to be made are designed as raised electrically conductive surfaces and with one pole of the voltage source are electrically conductively connected and that through an absorbent roller of the printing cylinder is moistened. To different patterns The rotary printing cylinder is advantageously made up of several to be able to print on interchangeable pressure wheels assembled. Particularly even, lengthways Coating-free zones running in the direction of travel of the film are obtained when the rotary printing cylinder executes a relative movement in the direction of travel of the film with respect to the film.

A simple contacting of the foil without damaging the remaining one Betgsflächen is made possible by a device in which one or more pressure wheels are electrically isolated from the rest and to the pressure wheels, which are isolated from one another different voltages are applied. For this purpose, each is isolated from each other Pressure smelling zveclrmä.Sigerveise each with one or the other pole of one Voltage source connected. Shall be direct current in a device of the type mentioned used so it is advisable that two electrodes opposite polarity arranged one behind the other in the direction of the film and are connected to the two poles of a DC voltage source. This will even with direct current a uniform destruction of the deposits in the metal-free making zones reached. A particularly clean metal-free zone is achieved, by making the contact surfaces of the electrodes in contact with the water convex are arched. This initially creates the central area of the zone to be destroyed of the pavement is destroyed and from there the entire zone is covered. An island formation within a zone to be cleared is therefore excluded.

The invention is explained in more detail below with the aid of examples.

Figure 1 shows an example of a device according to the invention in partially cut and broken view.

Figure 2 shows a rotary printing roller according to the invention, which from is composed of several pressure wheels.

A capacitor band 1 with a metal coating shown hatched 2 is coated on a rotatably mounted, electrically conductive rotary printing roller 5 passed with raised electrically conductive surfaces 6, the electrically Roll conductive surfaces 6 on the metal covering 2. The electrically conductive 12 stand 6 are convex and become absorbent when immersed in tap water 16 Roller 15 is wetted. An electrlsc1 conductive roller 17 is connected to the supply line 18 connected to one pole of a voltage source and makes contact with the covering 2. The rotary printing roller 5 is connected via lead 19 to the second pole of the voltage source. That Capacitor band 1 is moved in direction A. That on the convexly curved electrically Water adhering to the conductive surfaces 6 of the rotary printing roller 5 wets the covering 2, the current flowing through it destroys the metal coating 2 in the area of the electrical conductive contact surfaces 6 starting from the center to the outside. The water will removed from the capacitor strip 1 through the suction nozzle 21 and the suction channel 20.

A rotary pressure roller 7 contains pressure wheels 8,10 with different shaped and arranged electrically conductive contact surfaces 9, 11, 14 and insulating disks 12 and an electrically insulating shaft 20. Each of the electrically conductive surfaces 9, 11, 14 is driven by a separate absorbent and electrically conductive roller 27, 22, 23 wetted and contacted at the same time. The rollers 27, 22, 23 dip respectively in separate, water containing vessels 24, 25, 26 and are connected to different Tensions laid. An insulating film with a metal covering is attached to this roller passed and over an intermediate layer of water with the electrically conductive surfaces 9, 11, 14 brought into electrically conductive contact, it already flows without one further power supply from one pressure wheel to the next via the metal covering a current that causes the desired destruction of the metal coating in the area of the contact surfaces 9, 11, 14 made possible.

18 claims 2 figures

Claims (18)

P a t e n t a n s p rü ch e Procedure for removing limited areas the metal coverings of an insulating material layer provided with metal coverings, in particular a capacitor film for electrical capacitors with regenerable thin Coverings that do not indicate that the zones to be removed of the metal coverings wetted with almost pure water, the respective coverings with one and electrodes that are in contact with the water with the other Pole of a voltage cell are electrically connected and that after this caused destruction of the coverings in the areas of wetting the water removed will. 2. The method according to claim 1, d a d u r c h g e k e n nz e i c h n e t that layers of insulating material provided with aluminum coverings are used. 3. The method according to any one of claims 1 or 2, d a -d u r c h g e does not indicate that tap water is used. 4. The method according to any one of claims 1 or 2, d a -d u r c h g e does not indicate that distilled water is used. 5. The method according to any one of claims 1 to 2, d a -d u r c h g e does not indicate that distilled water with a small addition of a Acid or base is used. 6. The method according to claim 5, d a d u r c h g e k e n nz e i c h n e t that ammonia is added to the water. 7. The method according to any one of claims 1 to 5, d a d u r c h g e it does not indicate that the water is removed by blowing or suction. 8. The method according to any one of claims 1 to 7, d a d u r c h g e does not indicate that heat is used to remove the water will. 9. Device for performing the method according to one of the claims 1 to 8, d u r c h e k e n.n -z e i c h n e t that the supply line for the water is arranged in the electrode in contact with the water. 10. The device according to claim 8, d a d u r c h g e.k e n nz e i c It does not mean that the electrode has the shape of a tube. 11-. Device according to one of Claims 9 or 109 d a -d u r c it is noted that the electrode is a transmission sphere similar to the of a ballpoint pen. 12. Device for performing the method according to one of the claims 1 to 8, that is, that the with the water in contact standing electrode is a rotary printing cylinder on which the coating to be made free Zones formed as raised electrically conductive surfaces and with one pole the voltage source are connected and that the electrically conductive surfaces through an absorbent roller moistened sverden. 13. The apparatus of claim 12, d a d u r c h g e k e n nz e i c fl n e t that the rotary printing cylinder consists of several interchangeable printing wheels is composed. 14. Device according to one of claims 12 or 13, d- a -d u r c it is noted that the rotary printing cylinder is used to remove In the direction of travel of the film, longitudinal strips made from the layers of a capacitor track compared to this a relative movement in or opposite to its direction of travel exit. 15. Device according to one of claims 13 to 14, d a -d u r c h It is not indicated that one or more small presses are electrical against the rest are isolated and that the pressure wheels, which are isolated from one another, have different electrical voltages are applied. 16. The apparatus of claim 15, d a d u r c h g e k e n nz e i c h n e t that each of the mutually isolated pressure wheels each with the one or the other pole of a voltage source. 17. Device according to one of claims 9 to 16, d a -d u r c h it is not noted that there are two electrodes of opposite clarity arranged one behind the other in the running direction of the film and one with the two poles DC voltage source are connected. 18. Device according to one or more of claims 9 to 17 d it is not indicated that those in contact with the water Contact surfaces of the electrodes are convex.