DE2334039A1 - IMPROVING THE BINDABILITY OF MATERIALS WITH A SMOOTH SURFACE - Google Patents

Description

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P 64-83

Dodge Industries, Inc,

Hoosick Falls, New York, New York, USA

Improving the ability of materials to bind with

smooth surface

The invention relates to the improvement of the binding capacity of materials with a smooth surface or such materials, a process for their production and their use, in particular for printed circuits.

Many plastics and metals, especially in the form of foils, tapes or very thin films, are extremely smooth Surfaces. The smooth surfaces of these plastics diminish their ability to bond with adhesives, inks, coatings, metals, etc., especially with regard to such substances, which do not bond chemically with the plastic or metal surface involved or have an affinity for it.

The bonding properties of smooth metal surfaces, such as those on metal plates, strips and foils, and in particular Copper and nickel foils were made by depositing metal

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particles, especially copper particles, on these surfaces by electroplating from electrolyte solutions Current densities over layers conventionally used in plating processes are improved. The kind of through this surface produced by similar methods has been referred to as a granular, treated, or dendritic surface. For the convenience of the description and not for the purpose of limitation, surfaces of this type are referred to below as dadritic or treated. Such surfaces can using the methods described in U.S. Patents 3,220,897 and 3,328,275 and British Patent 1,014,982 can be obtained. However, the invention does not apply to those produced by the aforementioned processes Surfaces limited because of similar surfaces, according to produced by other methods may also be satisfactory.

The dendritic, formed on the surface of a metal foil The deposit is so fine that the surface of the film obtained is enlarged by a very large factor. the The binding capacity of the metal foil is increased by the dendritic deposition to such an extent that the binding strength is proportional to the surface area of the material. In addition, between an applied Zleberschiciit and the fine dendritic surface formed on the metal foil to form a mechanical lock, "and this contributes to the binding ability of the treated. Foil when glue is used with the foil.

The invention is intended to improve the binding properties of Y, -ir.Bts ~ .c, f.f5n and metals in the form of foils, tapes and thin films, rare formation of a surface, ice-like

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is a metal foil plated with a dendritic deposit, it is said to be mechanically on a non-conductive form a surface that has binding capabilities similar to those a metal foil plated with a dendritic deposit, has the retention capacity of plastics Improve ink or printing inks and paints, printed using the additive circuitry method Create circuits, then printed on almost any type of plastic, including flexible plastic Enabling circuits and the plating of metals on plastics by vacuum metallization and sputtering processes to enhance.

Further aims and possibilities of the invention emerge from the following description, claims and figures.

In general, the invention lies in increasing the binding capacity of materials with a smooth surface, such as plastic or metal foils, tapes and thin films. In the case of plastics, this is achieved by using a metal foil with a dendritic surface pressed against a smooth surface of the plastic to create a mirror image of the Metal foil with a dendritic surface in the smooth surface of the plastic. The dendritic surface can be on a heated roller rather than on a metal foil be provided when thermoplastic materials with a smooth surface are used. The mirror image surface created in this way can be used to create a similar surface in another material with a smooth surface will. A plastic or metal foil, tape or thin film can also be applied to a metal foil with a dendritic surface be poured on, in order to have a mirror image of the dendri-

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tables surface. The teaching according to the invention can also be used to manufacture printed circuits using the additive circuitry method can be used on rigid as well as on flexible materials. A treated plastic can after Vacuum metallization process or metal plating by the sputtering process. The metal plating process can be used to manufacture printed circuits on the treated plastic.

The invention thus applies a treated metal, or like it sometimes also called a metal with a dendritic surface , which may be in film, strip or other suitable form to the bondability of the materials by transferring the properties of the metal with a dendritic surface to the surfaces of these materials to improve.

The material according to the invention has a smooth surface and a surface similar to a metal foil having a dendritic surface formed thereon. The one with a metal foil A surface similar to a dendritic surface is preferably a mirror image of a metal foil with a dendritic surface. According to a particularly advantageous embodiment of the invention Material this is a plastic or thermoplastic film or an adhesive. Is particularly advantageous thereby a biaxially oriented plastic film, which is metal applied to at least a portion of the surface similar to the dendritic metal surface.

The method according to the invention for producing a material with a smooth surface and increased binding capacity, in particular a material of the aforementioned type is characterized

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from that a material with a smooth surface with a material with dendritic surface, forming an image of the dendritic surface in the material with smooth Surface brought into contact and the material with a smooth surface and the material with a dendritic surface underneath Leaving behind an image of the material with a dendritic surface created in the material with a smooth surface is separated. The preferred material with a dendritic surface is a * metal with the formation of a Mirror image used in the material with a smooth surface. In a particularly advantageous manner, the material becomes smoother Surface and the metal with dendritic surface brought into contact with one another by pouring on. It can be from It may be advantageous to do this under pressure and / or at elevated temperature. In a special embodiment of the inventive method is used as a metal with dendritic Surface uses a dendritic copper deposited by plating on copper foil. The deposition has proven itself from an electrolyte solution at higher current densities than commonly used in plating processes. Even it can be advantageous to insert a material with a smooth surface and the metal with a dendritic surface Use release agent, which is applied to the metal with a dendritic surface, on the material with a smooth surface or can be incorporated into the material with a smooth surface. In a further variant of the method according to the invention the material made with a mirror image of the metal with a dendritic surface is made with a smooth surface with a second material with a smooth surface for forming an image of the metal with a dendritic surface in the second material brought into contact with a smooth surface. The second material with a smooth surface is

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part way to the first material with a smooth surface and poured onto the mirror image of the metal with a dendritic surface.

Further details, features and advantages of the invention emerge from the following description of the figures; in this demonstrate

Pig. 1 to 4 show the steps of an embodiment of the invention to increase the binding capacity of a smooth surface of a plastic or metal film or foil or tape;

Fig. 5 shows the use of a film with a mirror image of a Metal foil with a dendritic surface to form a similar surface in another material with a smooth surface;

6 to 10 individual steps of the method according to the invention, how they are used for the manufacture of printed circuits by the additive circuit process;

11 and 12 show a modification of the invention in use a cast film;

13 and 14 a further modification of the invention, as they applied to the manufacture of printed circuits according to the sputtering and vacuum deposition method will and

15 and 16 show a modification of the invention for production a plastic film in which only selected areas have improved binding properties.

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An application of the invention is shown in FIGS. 1 to A, making the binding ability of a plastic film strong is improved. In this and the other figures are the irregularities of the dendritic surfaces and that produced by contact with the dendritic surfaces Surfaces have been greatly exaggerated for illustrative purposes.

According to the invention, a copper foil 11 with a dendritic Surface 13 with a surface 15 of a smooth material, such as a plastic film 17, are brought into contact. Of the Plastic film can for example be a thermoplastic. The dendritic surface of the metal foil and the surface of the Plastic films are exposed to each other under pressure and at increased Temperatures transmitted by rollers 19 and 21 in contact brought. The roller 19 is preferably made of rubber and the roller 21 made of steel. The roller 21 can be heated in a conventional manner in order to obtain the amount required to soften the plastic film to deliver elevated temperatures. Pressure and elevated temperatures can also be achieved by other conventional devices, such as e.g. plate presses etc. For any thermoplastic film chosen, of course, the temperature will be the Pressure and the length of time the heat and pressure are applied to the film will vary.

Purpose of contacting the dendritic surface of the Metal foil with one surface of the plastic film is the Formation of an exact replica or mirror image of the dendritic metal surface in the plastic. For each survey in the dendritic surface of the metal foil results in a corresponding depression in the surface of the plastic film, and for ae.de recess in the dendritic surface of the metal foil there is a corresponding elevation on the

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Surface of the plastic film. The treated surface in other words, the plastic film is a mirror image or negative image of the dendritic metal surface.

After the mirror image has been formed in the plastic film, the metal foil with a dendritic surface is restored removed. To avoid the painful removal of the metal foil from the To enable plastic film, a release agent can be applied to the dendritic surface of the metal foil, before it is brought into contact with the plastic. Some widely used release agents are silicones, hydrocarbons and polytetrafluoroethylene (Teflon). On the other hand, a release agent can also be used on the plastic film before it is brought into contact with the metal foil. The choice of a release agent to apply to Plastic film depends on the need to remove this, and the ability to easily remove this from the film after the Remove treatment, starting. For example, a hydrocarbon separating agent can easily be mixed with a suitable solvent removed.

Another possibility is to introduce a plasticizer that liquefies under elevated temperatures and pressures Kind in the plastic film. The plasticizer can then can be removed from the plastic film with the help of heat and pressure, causing it to come to the surface as a liquid leaves. If the plasticizer comes to the surface as a liquid between the metal foil and the plastic film, it works he as a release agent. Another way of enabling the separation of metal foil with a dendritic surface and a The pressed-on plastic film consists of a metal foil with a dendritic surface with a minimal tendency to bond to select.

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The treated plastic! Im 17 has after the removal of of the copper foil 11 with a dendritic surface has a surface with a mirror image of the foil with a dendritic surface Surface. This treated surface, now designated 23, has an area which is much larger than the area in untreated condition. The surface 23 has extremely fine irregularities, similar to those of the metal foil with a dendritic surface, and these irregularities hold glue, inks or printing inks, coatings, metal etc. when applied to it.

In another embodiment of the invention, the plastic film 17 is provided with a mirror image of the metal foil dendritic surface, formed as surface 23, for treating the surface of another plastic film used. In other words, the mirror image formed on the surface 23 of the metal foil with a dendritic surface can be transferred to another plastic film 25. As shown in Figure 5, this is done by contacting the treated surface 23 of the film 17 with a Surface of the film 25 under pressure and at elevated temperatures achieved. Rolling or other methods of applying heat and pressure can be used, but are used The clarity of the representation is not shown in the figures. To obtain satisfactory results after this modified procedure To achieve this, the first plastic film 17 should be a high-temperature plastic be with little flow. By suitable selection of the plastic films, an easy separation can be achieved of plastic films 17 and 25 after the end of pressure and elevated temperatures can be achieved.

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A mirror image of a metal foil with a dendritic surface can also be used on biaxially oriented films, such as e.g. a polyethylene terephthalate (PET) using the teaching according to the invention in a suitable manner below described modification are produced. This can be done in any suitable device that uses heat and pressure uses, v / ie for example a roller laminator, plate press, etc. Will e.g. be a roller laminator is used, the PET film is passed through the nip in contact with a metal foil with a dendritic surface brought. Usually a roll of the laminate or f .; stole and the other rubber. The steel roller can be heated and the PET film is no longer heated Steel roller touches. Nip pressure and temperatures » and the speed of the film feed "through the rollers can be varied. However, temperatures in Bc-roeich from 205 - 2> 0 ° C (400 - 430 ° F) for the heated stilt roller recommended. The speed of the film can range from 0.6 to 6 m / min (2 to 20 cracks / min) and the nip pressure zv.'ischen 4, ^ 7 "to 17.86 krr / cm (25 pounds to 100 pounds per linear inch). A treated (i.e., one with a mirror image of a dendritic surface) Polytetrafluorethylene (Teflo: a) film can be used instead of the Metal foil with dendritic surface can be used because E r a high-temperature plastic 1 i.vl and good separating properties owns.

Another use of the treated; Art st of films with a mirror image surface 2 $ of a metal foil with the -third :; shear surface is shown in Figs. This use lies in the production of printed Schsltunyen according to dom AdaitivschsK: r: - isverfshren. The surface- 25 i-oc Kunststoffilms 17, shown in Fig. 6, which ei.- ,. SpiegolLIl-1

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BATH ORIGINAL

a dendritic surface of a copper foil 11 is obtained has, is coated with an adhesive 27 or has already been poured on, which has a Maintain and maintain imprint. The plastic film and Pein glue 27 are then attached to a carrier 29 for the printed circuit brought into contact.

The carrier for the printed circuit can be made by laminating several layers of resin-impregnated paper or glass fabric getting produced. Laminating is usually done in a platen press with the aid of heat. The plastic film is aligned against the carrier 29 so that the adhesive faces the carrier 29, and pressure and heat are in the manner shown in Fig. 8 in a plate press, then the plastic film 17 is removed and leaves the KIe-

29
Bonded back via 27 to the substrate / for the printed circuit as shown in FIG. The adhesive now has a surface 31 which is similar to the dendritic surface I3 of the metal foil. -

Using conventional methods, the surface 31 of the Klebers 27 is so sensitized and activated that it is the Electroplating of copper is accessible. One or more conductor tracks will be on selected parts of the sensitized and activated adhesive by electroplating made of copper 33 by conventional methods.

The traditional sensitization and activation procedures for plating non-conductive surfaces are not currently used for additive circuits, primarily because the bond between the non-conductive material and the deposited copper is too weak. Using the

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According to the invention, an excellent bond between the electroplated copper and the adhesive-coated copper will be achieved Circuit carrier achieved. Electroplating ensures that copper works in even the finest surface imperfections of the adhesive is deposited, creating a strong bond. This method to improve The bond is not only applicable to glue, but also to all types of smooth plastics, since the formation the dendritic surface in the adhesive or plastic is a mechanical matter rather than a chemical one Reaction. The same procedure can be used to completely coat or coat a surface as only parts that form a circuit.

A plastic film treated according to the teaching of the invention has a surface to which inks or printing inks, paints, etc. adhere well. For example, it is assumed that the formation of such a surface on a substance that is difficult to coat such as s.B / polytetrafluoroethylene plastic film that Application of printing ink to the surface allowed. An advantage of this type of treatment for plastic lies in the fact that they do not paint the plastic surface and even the one on this surface through this treatment generated matt gloss disappears when the plastic is printed.

Figures 11 and 12 illustrate the application of the invention to a film formed by casting on a carrier will. Polyimide films are typical of films formed in this manner. Metals with a low melting temperature, e.g. Solder f can be formed as films by pouring onto substrates. In this application, the film 41 is

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233A039

NEN carrier 43 cast with a surface 45 which either is a dendritic deposit or its image. Once the film has solidified, it is removed, whereby a Surface 47 with a mirror image of surface 45 retains.

Another application using the treated film of this invention is in manufacturing a metallized film by the sputtering or vacuum deposition method. Films such as those made of polyethylene terephthalate are metallized and used as reflective surfaces. The currently maintained bond between the metal and film using these methods is quite small, allowing wider application of such Films limited. A plastic film with one according to the teachings The treated surface obtained according to this invention and metallized by one of these processes has a firm bond between the plastic film and the deposited metal.

The teachings of the invention can also be used to make a printed Switching on PET film or other flexible plastic be applied. This can be as shown in FIGS 14 and described below can be achieved:

1. Treat the polyethylene terephthalate film 51 according to uses the teachings of the invention to create a mirror image 53 of a metal foil with a dendritic surface on a surface to obtain;

2. The treated surface parts of the PET film are masked, where metal deposition is not desired, with suitable masking 55;

3. The unmasked areas 56 of the treated ones are metallized Surface of the PET film using conventional catheters

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atomization or valorum separation process at 57; and

4. The partially metallized PET-PiIm is electroplated to build up the conductor thickness of the printed circuit pattern 59 "up to the gex-riinschten thickness. Alternatively, the printed switch cluster up to the desired thickness by continuing the sputtering or vacuum deposition process being constructed. A number of metals can be used to metallize the FET film however, copper comes first.

FIGS. 15 and 16 show the application of the invention thermoplastic films and rigid substrates for forming a treated surface anywhere, or at least on one Part of such a film surface. A dendritic surface 61 is formed on at least part of the surface on a Stab.lv/alze 63. In this representation, the Dendritic surface patterned so that a treated pattern or webs are created on a thermoplastic film will. Such a treated film can be used to make a printed circuit board. The film is between the steel roller 63, which is carried out in a conventional manner can be heated, and a hard rubber roller 67 passed through it. The temperature of the heated roll, the pressure applied at the nip by the rolls, and the Speed of the film through the rollers, varies according to the particular thermoplastic film being treated. After your pass through the reels the film 65 has areas 69 on its surface 7Ί with mirror images of the dendritic surface 61 of the roller 63. The treated film can be used in the manufacture of printed Circuits using the additive circuit process described above be used.

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Claims (31)

Claims 1J material with a smooth surface and one on top formed metal foil with a surface similar to a dendritic surface. 2. Material according to claim 1, characterized in that net that that of a metal foil with a dendritic surface similar surface is a mirror image of a metal foil with a dendritic surface. 3. Material according to claim 1 or 2, characterized in that g e k e η η that it is a plastic or thermoplastic film. 4. Material according to claim 1 or 2, characterized in that g e k e η η ^ that it is a glue. 5 · Material according to claim 1 or 2, characterized in that g e k e η η • draws that it is a biaxially oriented plastic film. 6. Material according to any one of claims 1 to 5i characterized _t that metal on at least a portion of the similar surface is applied. 7. A method for producing a material with a smooth surface and increased binding capacity, in particular one Material according to one of claims 1 to 6, characterized ge denotes that a material with smooth Surface with a material with a dendritic surface forming an image of the dendritic surface 309886/1073 brought into contact with the smooth surface material and the smooth surface material and the material with a dendritic surface, leaving an image of the material in the material with a smooth surface is separated with a dendritic surface. 8. The method according to claim 7i, characterized in that that the material with a dendritic surface is a metal with the formation of a mirror image in the material is used with a smooth surface. 9. The method according to claim 8, characterized in that the material with a smooth surface with the metal is brought into contact with the dendritic surface by pouring onto it. 10. The method according to claim 8 or 9? thereby g e k e η η draws that the material with smooth surface with the metal with dendritic surface under pressure and / or is brought into contact at an elevated temperature. 11. The method according to any one of claims 8 to 10, characterized in that the metal with dendritic Surface a dendritic copper deposited by plating on copper foil is used. 12. The method according to claim 11, characterized in that the dendritic copper is deposited by deposition an electrolyte solution at higher current densities than commonly used in plating processes. 13. The method according to any one of claims 8 to 12, characterized in that the material with smooth 30988 6/1073 Surface a plastic oäec thermoplastic film is used. 14. The method according to any one of claims 8 to 13, characterized characterized that between the material with smooth surface and the metal with dendritic Surface a release agent is used. The method according to claim 14, characterized in that the release agent is applied to the metal with dendritic surface is applied. 16. The method according to any one of claims 8 to 14, characterized characterized in that the release agent is applied to the smooth surface material. 17 · The method according to any one of claims 8 to 14, characterized in that the release agent in the material is introduced with a smooth surface. 18. The method according to claim 8, characterized the
net that the material with a smooth surface and the metal with a dendritic surface are selected with the formation of a minimal tendency to bond with one another. 19. The method according to any one of claims 8 to 18, characterized characterized in that the material produced with the mirror image of the metal with a dendritic surface with a smooth surface with a second material with a smooth surface to form an image of the metal with dendritic surface in the second material is brought into contact with a smooth surface. 309886/1073 20. The method according to claim 19, characterized in that the second material with smooth Surface on the first material 'with a smooth surface and with is poured onto the mirror image of the metal with a dendritic surface. 21. Use of the material according to any one of claims 1 to 6 in a process for improving the bond between a plastic film and vacuum metallizing applied Metal, one surface of the plastic film with a Metal foil with dendritic surface for forming a mirror image of the metal foil with dendritic surface brought into contact in the surface of the plastic film, the plastic film and the metal foil with a dendritic surface leaving a mirror image of the metal foil with a dendritic surface formed in the plastic film separated and metal applied to the mirror-inverted surface of the plastic film by means of Vacuuminet aiii er s will. 22. Use of the material according to one of claims 1 to 6 in a method for improving the bond between a Plastic film and applied by vacuum metallizing The metal of claim 21, wherein the metal is vacuum metallized only on selected areas of the mirror-image-shaped Surface of the plastic film for the formation of ' Conductor traces is applied to the film. 23 · Use of the material according to claim 21, v / ob ei. Metal is applied by vacuum metallization only to selected areas of the mirror-inverted pressed-in surface of the plastic film to form a carrier for conductor tracks on the film. 309886/1073 24. Use of the material according to claim 22, wherein the application of the metal only on selected areas of the mirror image surface by shielding the parts of the mirror image Surface that are not selected takes place. 25 · Use of the material according to claim 23, wherein the Applying the metal only to selected areas of the mirror image surface by shielding the portions of the mirror image Surface that are not selected takes place. 26. Use of the material according to one of claims 1 to 6 in a process for improving the bond between a plastic film and sputter deposited Metal, one surface of the plastic film with a Metal foil with dendritic surface forming a mirror image of the metal foil with dendritic surface brought into contact in the surface of the plastic film, the plastic film and the metal foil with dendritic surface leaving a mirror image of the dendritic surface metal foil in the plastic film and metal by sputtering onto the mirror image Surface of the plastic film are applied. 27 · Use of the material in a method according to claim 26, wherein -Parts of the mirror-inverted shaped surface of the plastic film to avoid the deposition of metal be shielded on these parts. 28. Use of the material according to one of claims 1 to 6 in a method for producing a printed circuit, a plastic with a smooth surface with a metal with a dendritic surface under pressure and / or temperature 309886/1073 7334039 temperature for forming a mirror image of the metal with a dendritic surface in the plastic with a smooth surface brought into contact, the plastic with a smooth surface and the metal with a dendritic surface underneath Leaving a mirror image of the dendritic surface metal in the plastic separated, on selected ones A sensitizing coating is applied to areas of the mirror-image plastic surface and the Sensitized areas of the mirror-inverted plastic surface for the formation of conductor paths plated thereon will. 29 .. Use of the material according to one of the claims 1 to 6 in a process for the production of a printed circuit, wherein a plastic film with a smooth surface with a metal with a dendritic surface to form a mirror image of the metal with a dendritic surface in the smooth surface brought into contact, the smooth surface of the plastic film and the metal with dendritic surface leaving a mirror image of the metal with dendritic surface, impressed in the smooth surface, separated, an adhesive applied to the mirror-image surface of the plastic film as a coating, the Adhesive bonded to an insulating substrate, the film separated from the adhesive surface leaving an image of the dendritic surface metal on the adhesive surface, a sensitizing coating applied to selected areas of the adhesive surface, and the sensitized areas of the adhesive surface ζχιτ formation of conductor tracks are plated thereon. 30. Printed circuit, indicated by an insulating support, a material bonded thereto 309886/1073 7334039 smooth surface, one, a metal foil with dendritic Surface similar, impressed on the material with a smooth surface. Surface and in tracks on the indented Surface applied metal. 31. Printed circuit according to claim 30, characterized in that the material with a smooth surface is an adhesive. 309886/1073 Blank page