KR100747627B1 - Method for producing 2 layered conductive metal plated polyimide substrate - Google Patents

Abstract

A method for manufacturing a two layered conductive metal plated polyimide substrate is provided to improve plating, adhesion intensity, heat-resistance, and chemical resistance properties by not using an adhesive layer. A method for manufacturing a two layered conductive metal plated polyimide substrate includes the steps of: etching a plane of a polyimide film by an etching solution selected from a group of KOH, ethylene glycol, a KOH mixed solution, NaOH, a pyrrolidone and NaOH mixed solution, or a chromic anhydride and sulfate mixed solution; absorbing a catalyst on the polyimide film; forming a first conductive metal film without applying a current to the polyimide film having the catalyst; drying the first plated polyimide film under an inactive gas atmosphere at a temperature range of 110 - 200 degrees centigrade for 5 - 30 minutes; and forming a second conductive metal film by applying a current to the first dried plated polyimide film.

Description

A method for producing a conductive metal plated polyimide substrate having a two layer structure {Method for producing 2 layered Conductive metal plated polyimide substrate}

1 is a graph comparing the average adhesion strength of the conductive metal plated polyimide substrate having a two-layer structure prepared according to the Examples and Comparative Examples of the present invention.

2 is a graph comparing the flex resistance of a conductive metal plated polyimide substrate having a two-layer structure prepared according to Examples and Comparative Examples of the present invention.

The present invention relates to a method for producing a conductive metal plated polyimide having a two layer structure, in particular a method for producing a conductive metal plated polyimide having a two layer structure by a plating method.

A flexible copper clad laminate film (hereinafter referred to as "FCCL"), a core material of a flexible printed circuit (hereinafter referred to as "FPC"), is largely composed of an insulating film layer and a conductive metal layer.

Generally, polyester, polyimide, liquid crystal polymer, fluororesin film and the like are used as the insulating film layer, but a polyimide film excellent in heat resistance, dimensional stability, and solderability is preferred.

On the other hand, gold, copper and the like are used as the conductive metal layer having low electrical resistance and excellent conductivity, but copper which is advantageous in terms of price is mainly used.

At present, in terms of the method of laminating the insulating film layer and the conductive metal layer, the FCCL is roughly divided into the FCCL composed of the insulating layer, the adhesive layer and the conductive metal layer, and the two-layer FCCL composed of the insulating layer and the conductive metal layer, depending on whether the adhesive layer is present. However, in terms of physical properties, the three-layer FCCL is a preferred two-layer FCCL due to the adverse effect of the adhesive, such as the difficulty of forming a fine pattern after the completion of the circuit, the problem of flexibility.

The production method of FCCL largely includes lamination method, casting method and plating method.

The lamination method is a method of producing a laminated FCCL by applying a polyimide adhesive on a polyimide film, baking in an oven to fix an adhesive layer, and then placing a copper thin film on the polyimide film and pressing.

The casting method is widely used as a two-layer FCCL production method, and is a method of producing a two-layer FCCL by applying a liquid polyimide film precursor to a water layer on a standard-made copper thin film, drying and curing in a high temperature oven. However, since the casting method uses commercially available copper foil, the limitation of the copper foil manufacturing technology is a disadvantage, and it is very difficult to control the thickness of the copper foil to 10 μm or less.

Meanwhile, the plating method is a method of manufacturing FCCL by forming a submicron-thick metal conductive layer called a seed layer by sputtering or vapor deposition on a commercially available polyimide film, followed by electroplating to laminate a copper thin film. . The FCCL produced by this plating method is specifically referred to as a conductive metal plated polyimide substrate.

Since the plating method does not use a commercially available copper foil used as a conductor layer in the lamination method or the casting method, there is an advantage that the thickness of the copper foil can be adjusted by electroplating after sputtering. However, in the plating method, since the process of generating the metal conductive layer is performed in a vacuum, a high equipment cost is required, resulting in high product cost, and nickel (Ni) and chromium (used as seed layers in the process of processing FCCL products into FPCB or COF). An additional etching process is required for the removal of Cr), cobalt (Co), and the like, and the adhesive strength between the copper thin film and the polyimide film is inferior to other manufacturing methods. In particular, in addition to these technical aspects, the plating method has a problem that it is difficult to obtain a usable polyimide film. In addition, the FCCL produced by using the conventional plating method has a problem that its physical properties such as peel strength is inferior to the FCCL manufactured by other methods.

The present invention seeks to provide a novel method for producing a conductive metal plated polyimide substrate which is a FCCL having a two layer structure.

In order to solve the above technical problem, a method for producing a conductive metal plated polyimide substrate having a two-layer structure according to the present invention is a) a polyimide membrane surface KOH, ethylene glycol and KOH mixed solution, NaOH, pyrrolidone And etching with an etching solution selected from the group consisting of a mixed NaOH aqueous solution, or a mixed solution of chromic anhydride and sulfuric acid; b) adsorbing a catalyst on said polyimide membrane; c) a first plating step of forming a first conductive metal film without applying current to the polyimide film to which the catalyst is adsorbed; d) drying the first plated polyimide film for 5 to 30 minutes in an inert gas atmosphere within a temperature range of 110 ° C. to 200 ° C .; And e) a second plating step of applying a current to the dried first plated polyimide film to form a second conductive metal film.

A conductive metal plated polyimide substrate having a two-layer structure according to an embodiment of the present invention is obtained by plating a conductive metal on a polyimide film. Accordingly, the conductive metal plated polyimide substrate having the two-layer structure of the present invention includes a conductive metal film and a polyimide film.

The polyimide film used in the present invention is not particularly limited as long as it can be used in the plating process of the conductive metal, and may be a multilayer polyimide film or a single layer polyimide film.

In the embodiment of the present invention, for convenience of description, FCCL using a copper thin film as the conductive metal is described as an example of the conductive metal plated polyimide substrate, but the protection scope of the present invention is not limited thereto.

The conductive metal plated polyimide substrate having a two-layer structure according to an embodiment of the present invention includes a polyimide film and a copper layer and does not include a separate adhesive layer.

The method for producing a conductive metal plated polyimide substrate having a two-layer structure according to the present invention is largely divided into a degreasing process, an etching process, a neutralization process, a coupling process, a catalyst addition process, a reaction acceleration process, an electroless plating process, and a plating process. It may include.

Hereinafter, a method of manufacturing a conductive metal plated polyimide substrate having a two-layer structure according to the present invention will be described in detail.

1. Degreasing process

The degreasing process is a process for removing impurities on the surface (pollution, fats, fingerprints, etc.) generated during the production or handling of polyimide. When the impurities are not removed, the peel strength of the conductive metal-plated polyimide substrate (Peel Strength, Significant adverse effects on adhesion strength).

The degreasing solution component is not particularly limited in the embodiment of the present invention, it is possible to use an alkali-based rinse or shampoo used.

In the embodiment of the present invention, the degreasing temperature range is about 20 to 40 ℃, the holding time of the degreasing process is maintained for about 1 to 5 minutes. When the temperature range of the degreasing process is 20 ℃ or less, the activity of the degreasing solution is low to achieve the desired degreasing effect, when the temperature range of the degreasing process is more than 40 ℃ it is difficult to properly control the process treatment time.

In addition, ultrasonic waves may be applied during the present process to cause a continuous process. At this time, since the polyimide is a material having a high flexibility, continuous reaction is possible due to ultrasonic waves.

2. Etching Process

The polyimide obtained by the degreasing process is immersed in an etching solution at about 45 to 60 ° C. for about 5 to 7 minutes, and the polyimide surface is modified by etching the polyimide surface. The etching solution is preferably a KOH, ethylene glycol and KOH mixed solution, NaOH, pyrrolidone and NaOH mixed aqueous solution, or a mixture of chromic anhydride and sulfuric acid.

Due to this etching process, the modified polyimide surface can enhance the peel strength by maximizing the adhesion between the plating layer and the polyimide layer in the subsequent plating process. This etching process cleaves the imide ring of polyimide, and converts imide into an amide group or a carboxyl group.

When the process temperature of such an etching process is 45 degrees C or less, the activity of etching liquid becomes low and a desired etching effect cannot be achieved. In addition, when the process temperature of the etching process is more than 60 ℃, it is difficult to control the overall uniformity and continuity on the polyimide surface due to the rapid progress of the etching, resulting in damage to the polyimide film.

In addition, ultrasonic waves may be applied during the present process to cause a continuous process. At this time, since the polyimide is a material having a high flexibility, continuous reaction is possible due to ultrasonic waves.

3. neutralization process

The modified polyimide obtained in the etching process is immersed in HCl (hydrochloric acid) at room temperature for about 5-7 minutes to neutralize the polyimide surface.

This step removes or eliminates metal cations that are expected to remain on the polyimide surface obtained in the etching step. Removal of such metal cations promotes the reaction of the coupling process, which is a post process.

If the temperature of the neutralization step is 10 ° C or less, the activity of the reaction liquid is low and the desired neutralization effect cannot be achieved. Moreover, when the temperature of a neutralization process is 30 degreeC or more, adjustment of the workability of a process becomes difficult.

In addition, ultrasonic waves may be applied during the present process to cause a continuous process. At this time, since the polyimide is a material having a high flexibility, continuous reaction is possible due to ultrasonic waves.

4. Coupling process (polarization process)

The polyimide modified in the neutralization process is immersed in the coupling agent solution at about 30 to 45 ° C. for about one to several minutes.

This process binds the coupling agent where the imide ring of the polyimide surface is cleaved by the etching process to impart polarity on the polyimide, thereby facilitating the progress of subsequent plating processes and plating homogeneity and continuity of the desired product. To improve the peel strength.

Here, a silane group or an amine group is preferably used as the coupling agent. The coupling agent is not particularly limited as long as it can impart a coupling agent. As the coupling agent using the silane group as the coupling agent, a silane coupling agent containing aminopropyl triethoxy silane is preferably used. As the coupling agent using the amine group as the coupling agent, an alkali containing sodium oxide and monometal amine is used. System coupling agents or acidic coupling agents comprising ethylene diamine and hydrochloric acid are preferably used.

In one embodiment of the present invention, as the silane coupling agent, Shinetsu's coupling agent is used, but various commercially available products such as Japan Energy's product or Dow Corning's product can be used.

5. Catalyst addition process

The coupling-treated polyimide was immersed at room temperature for 5 minutes in a solution made by diluting a solution containing palladium chloride (PdCl ₂ ) and tin tin chloride (SnCl ₂ ) in a hydrochloric acid at a volume ratio of 1: 1, and the polyimide surface was immersed in a polyimide surface. Palladium and tin are adsorbed to the coupled coupling agent as a catalyst.

If the reaction time of this process is too short, the adsorption rate of palladium and tin as catalysts on the surface of polyimide is low, so that the desired catalytic effect cannot be achieved. If the reaction time is too long, the surface of polyimide is corroded by hydrochloric acid in the process solution. Adverse effects may occur.

6. Reaction Acceleration Process

In the catalyst addition step, the catalyst-added polyimide is immersed in a solution prepared by mixing hydrhydric acid and glycolic acid at room temperature for about 3 to 5 minutes, thereby desorbing only tin (Sn) adsorbed in the previous step and palladium on the surface. Only the ions are left, leaving the polyimide surface in an active state that is easy to plate.

If the reaction time of this process is too short, the desorption rate of tin on the surface of polyimide is low, and the remaining tin acts as an impurity in the subsequent plating process. If the reaction time is too long, palladium ions are formed by the acid contained in the process solution. Desorption can have an adverse effect.

7. Bottom plating process

First, an electroless copper plating solution composed of an aqueous EDTA solution, an aqueous solution of caustic soda, an aqueous formalin solution, and an aqueous copper sulfate solution is prepared.

The plating solution may include a small amount of a brightener component, a stabilizer component, etc. in order to maximize metal properties in addition to the above components. Such polishes and stabilizers function for the reuse of the remaining liquid after several uses and for the storage of the liquid for a long time.

Thereafter, the product of the reaction acceleration step is immersed in the electroless copper plating solution at a temperature of about 38 to 60 ° C. for about 1 to several minutes to perform electroless plating. The plating thickness obtained by this electroless plating can be adjusted with time. When the temperature of the electroless plating process is about 38 ° C. or less, the activity of the plating solution is low, so that unplating and partial plating proceed to achieve the desired effect, and the temperature of the electroless plating process is about 60 ° C. In the case of exceeding, the plating film lacking overall uniformity and adhesion due to rapid plating is formed.

This process is a lower coating process for the subsequent plating process, it is preferable to carry out for a time such that the polyimide surface is entirely unplated portion rather than the thickness of the plating. As a preferable lower plating thickness, about 0.1-0.3 micron is suitable. Here, when the lower plating thickness is 0.1 or less, smooth progress of electroplating is difficult due to high resistance, and when the lower plating thickness is 0.3 or more, long time plating is required, and thus the peeling strength of the plating surface by the subcomponent of the plating solution. Is likely to be lower.

8. Drying process

The bottom plated polyimide film was dried at a temperature of 110 to 200 ° C. for 5 to 30 minutes in an inert gas atmosphere to stabilize the bottom plated film. Ar is preferably used here as an inert gas.

Here, when the performing temperature of the drying process is less than 110 ° C, the under-plated polyimide film is not sufficiently dried, so that the desired adhesion strength and flex resistance cannot be achieved. In addition, if the performing temperature of the drying process exceeds 200 ° C., the underplated polyimide membrane is damaged and it is impossible to achieve the desired adhesion strength and flex resistance.

In addition, when the drying process is not performed under an inert gas atmosphere, since the copper component plated in the temperature range of the drying process reacts with oxygen in the air and oxidizes, subsequent plating processes may not be performed smoothly.

9. Plating process

First, an aqueous copper sulfate solution (CuSO ₄ -H ₂ O), sulfuric acid (H ₂ SO ₄ ), hydrochloric acid (HCl) is diluted with water (ion-exchanged water) to prepare a plating solution. The plating liquid of this embodiment may include a small amount of a brightening agent and an additive.

Thereafter, the product of the electroless plating process is put in the plating solution, and plating is performed by applying a 2 A current at about 20 to 35 ° C. for about 30 minutes to prepare a conductive metal plated polyimide substrate. At this time, stirring of the plating liquid is smoothed to minimize concentration unevenness of the plating liquid. Such plating conditions may be appropriately adjusted according to the thickness of the copper plating film to be obtained.

As the plating liquid that can be used in the present embodiment, a plating liquid of use (Enthone OMI, noble metal, NMP, etc.) may be used in addition to the prepared plating liquid. However, the plating process is performed slowly over a long period of time under conditions more moderate than those of commercially available plating solutions.

Prolonged plating time can minimize the generation of stress inside the plating film to lower the hardness and obtain a plating film excellent in strength and ductility.

10. Testing

The FCCL samples obtained according to the examples of the present invention were subjected to the adhesion test (peel strength) and the flex resistance test according to the JIS-6471 standard.

Hereinafter, the present invention will be described in detail with reference to examples so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

The polyimide used in the embodiment of the present invention is not particularly limited as long as it is a polyimide suitable for the plating process, and a product used may be used. For the following examples, a polyimide film sample (Apical, Kaneka Industrial Co., Ltd.) having a width of 100 mm, a length of 190 mm, and a thickness of 38 μm is prepared, and at about 150 ° C., in order to remove moisture contained in the polyimide film. It dried for 10 minutes and pretreated for FCCL manufacture. The following examples are suitable processes for the polyimide samples and it is evident that the process can be appropriately modified by those skilled in the art depending on the polyimide samples and conditions.

Example  One

The polyimide sample was immersed for 5 minutes at room temperature in an aqueous solution containing an alkali or acid series containing a surfactant.

Thereafter, the obtained polyimide sample was used as an etching solution of 5M NaOH, and immersed at a temperature of 45 for about 5 minutes to obtain an etched polyimide sample.

The obtained etched polyimide sample was then immersed in HCL 100 ml / l at room temperature for about 5 minutes to neutralize the surface.

Thereafter, the silane coupling agent containing aminopropyl triethoxy silane was diluted to 1.0% / l, immersed at a temperature of about 30 ° C. for 5 minutes, and dried at about 110 degrees for about 5 minutes to stabilize the coupling layer. .

Thereafter, the obtained sample was activated with an aqueous hydrochloric acid solution obtained by diluting hydrochloric acid (35% HCl) with distilled water in a 1: 3 volume ratio.

Thereafter, a mixture of palladium chloride and tin tin chloride prepared by mixing 0.5 g of palladium chloride (PdCl ₂ ) and ₂ g of tin tin (SnCl ₂ ) in 1 L of distilled water in hydrochloric acid (3.5% HCl) in a volume ratio of 1: 1. The sample was immersed in a diluted aqueous solution at room temperature for about 5 minutes to add a catalyst.

Thereafter, 60 g of hydrhydric acid (60%) and 43 g of glycolic acid were mixed in 1 L of distilled water and immersed for about 5 minutes in a mixed solution of hydrhydric acid and glycolic acid. Then, an electroless copper obtained by mixing an aqueous copper sulfate solution (15.8 g / L) with a mixed aqueous solution of EDTA, caustic soda, and formalin dissolved in 4.2 g of EDTA, 13.7 g of caustic soda, and 9.5 g of formalin in 1 L of distilled water. The sample obtained in the plating solution was immersed at a temperature of about 45 ° C. for about 1.5 minutes to perform a lower coating process.

The bottom coated sample was then dried for 10 minutes at about 110 ° C. under Ar atmosphere.

Subsequently, 130 g of copper sulfate aqueous solution (CuSO ₄ -5H ₂ O), 110 g of sulfuric acid (H ₂ SO ₄ ), and 10 ml of hydrochloric acid were diluted with 1 L of ion-exchanged water, and the lower-coated sample was coated at a temperature of about 25 ° C. Immersion was performed for about 30 minutes at, and plating was performed by flowing a current of 2A.

In this first embodiment of the present invention, a conductive metal plated polyimide substrate having a two-layer structure having a plated film of about 8 μm was obtained.

Example  2

In Example 1, 2 was performed in the same manner as in Example 1, except that 5 g of pyrrolidone, 15 g of NMP, and 125 g of NaOH were mixed with 1 L of distilled water as an etching solution. A conductive metal plated polyimide substrate sample having a layer structure was obtained.

Example  3

In Example 1, the same as in Example 1 except for using an acid-based coupling agent formed by mixing 7 g of ethylenediamine and 7 g of hydrochloric acid (35% HCl) in 1 L of ion-exchanged water instead of the silane coupling agent. To obtain a conductive metal plated polyimide substrate sample having a two-layer structure.

The physical properties of the conductive metal plated polyimide substrate having a two-layer structure obtained according to Examples 1 to 3 of the present invention are shown in Table 1 below. In order to evaluate the plating degree of the conductive metal plated polyimide substrate, the continuity of the conductive metal plated polyimide substrate plating was visually observed, and according to the JIS-6471 standard, the adhesion strength (peel strength; sample average value) and the bending resistance test (R = 0.38 mm, 500 g, sample mean value).

Plating accuracy Um Average adhesion strength (kg / cm) Flex resistance Example 1 ◎ 7.9 0.79 166 Example 2 ◎ 8.0 0.59 154 Example 3 ◎ 8.2 0.82 169

In the above table,? Denotes a case where the entire sample surface is uniformly and beautifully plated, ○ denotes a case where the sample surface is uniformly plated,? This point to many cases.

Example  4 to 6

In Examples 1 to 3, the conductive metal plating polyimide having a two-layer structure by performing the same as in Examples 1 to 3, except that the electroless nickel plating instead of the electroless copper plating of the lower plating process A substrate sample was obtained.

The electroless nickel plating solution used in place of the electroless copper plating solution is obtained by dissolving 45 g of sodium hypophosphite, 12 g of sodium citrate, 10 ml of ammonia water, and 40 g of hexahydrate nickel sulfate in 1 L of ion-exchanged water. 2 minutes were performed.

Plating accuracy Um Average adhesion strength (kg / cm) Flex resistance Example 4 ◎ 7.9 0.68 129 Example 5 ◎ 7.9 0.79 147 Example 6 ◎ 8.0 0.71 169

Example  7 to 12

In Examples 1 to 6, instead of drying the bottom plated polyimide sample at 110 ° C. for about 10 minutes, it was carried out in the same manner as in Examples 1 to 6 except that the polyimide sample was dried at 150 ° C. for about 20 minutes. A conductive metal plated polyimide substrate sample having a two layer structure was obtained.

The physical properties of the conductive metal plated polyimide substrate having a two-layer structure obtained according to Examples 7 to 12 of the present invention were tested and shown in Table 3 below.

Plating accuracy Um Average adhesion strength (kg / cm) Flex resistance Example 7 ◎ 7.9 0.78 147 Example 8 ◎ 7.8 0.86 146 Example 9 ◎ 8.1 0.72 148 Example 10 ◎ 8.0 0.76 149 Example 11 ◎ 8.0 0.81 155 Example 12 ◎ 8.1 0.82 159

Example  13 to 18

In Examples 1 to 6, instead of drying the bottom plated polyimide sample at 110 ° C. for about 10 minutes, the same procedure as in Examples 1 to 6 was performed except that the polyimide sample was dried at 200 ° C. for about 20 minutes. FCCL samples were obtained.

The physical properties of the FCCL obtained according to Examples 13 to 18 of the present invention are shown in Table 4 below.

Plating accuracy Um Average adhesion strength (kg / cm) Flex resistance Example 13 ◎ 7.7 0.91 164 Example 14 ◎ 8.0 0.92 167 Example 15 ◎ 8.0 0.89 178 Example 16 ◎ 8.1 0.88 179 Example 17 ◎ 8.0 0.94 165 Example 18 ◎ 8.0 0.92 169

As can be seen from Tables 3 and 4 above, it can be seen that when the drying temperature is set at 150 ° C or 200 ° C, the average adhesion strength and the flex resistance are increased. From these results, it can be seen that the stabilization of the lower plated film and the polyimide interface, the polyimidization in the polyamic acid, and the stability of the plated film are improved through the drying process.

Comparative example  1 to 6

In Examples 1 to 6, instead of drying the bottom plated polyimide sample at 110 ° C. for about 10 minutes, the same procedure as in Examples 1 to 6 was performed except that the plated polyimide sample was dried at room temperature for 30 minutes. Polyimide substrate samples were obtained.

The physical properties of the conductive metal plated polyimide substrate obtained according to Comparative Examples 1 to 3 of the present invention are shown in Table 5 below.

Plating accuracy Um Average adhesion strength (kg / cm) Flex resistance Comparative Example 1 ◎ 7.9 0.1 10 Comparative Example 2 ◎ 8.1 0.1 10 Comparative Example 3 ◎ 8.0 0.2 10 Comparative Example 4 ◎ 7.9 0.64 131 Comparative Example 5 ◎ 8.0 0.68 127 Comparative Example 6 ◎ 8.0 0.61 126

As can be seen from Table 5, in the case of Comparative Examples 1 to 3 in which the process temperature of the drying process was performed at room temperature, the adhesion strength thereof was 0.1 kg / cm to 0.2 kg / cm, followed by the conductive metals according to Examples 1 to 3 There is a significant difference from the adhesion strength of the plated polyimide substrate, which is 0.59 kg / cm to 0.82 kg / cm, and its bending resistance is also 10 in Comparative Examples 1 to 3, and the conductive metal-plated polyimide substrate according to Examples 1 to 3 There is a significant difference in the flex resistance of 154 to 169.

However, Comparative Examples 4 to 6 were carried out under the same experimental conditions of Comparative Examples 1 to 3, except that electroless nickel plating was performed instead of the electroless copper plating of the lower plating process. As can be seen in Table 5, it can be seen that the plating properties such as the average adhesion strength and the bending resistance of the plated film is lower heat than the conductive metal plated polyimide substrates of Examples 1 to 3 of the present invention.

As described above, Comparative Examples 1 to 6 were performed only by changing the process temperature of the drying process performed after the lower plating in Examples 1 to 6 of the present invention, as shown in Table 5, and the average adhesion strength of the plated film and It can be seen that the plating characteristics such as flex resistance are significantly lower in quality than the conductive metal plating polyimide substrates of Examples 1 to 6 of the present invention.

Comparative example  7 to 12

 Comparative Examples 7-9 are oxygen under atmospheric pressure in Examples 7-9 above, instead of drying the bottom plated polyimide sample at 150 ° C. for 20 minutes under Ar. A conductive metal plated polyimide substrate sample was obtained in the same manner as in Examples 7 to 9, except that the mixture was dried at 150 ° C. for 20 minutes in a nitrogen atmosphere.

Comparative Examples 10 to 12 except that in Example 13 to 15, instead of drying the bottom plated polyimide sample at 200 ° C. for 20 minutes under Ar, it was dried for 20 minutes at 200 ° C. in an oxygen / nitrogen atmosphere under atmospheric pressure. In the same manner as in Examples 13 to 15, a conductive metal plated polyimide substrate sample was obtained.

The physical properties of the conductive metal plated polyimide substrates obtained according to Comparative Examples 7 to 12 of the present invention are shown in Table 6 below.

Plating accuracy Um Average adhesion strength (kg / cm) Flex resistance Comparative Example 7 ◎ 8.0 0.33 38 Comparative Example 8 ◎ 8.1 0.35 42 Comparative Example 9 ◎ 8.0 0.32 38 Comparative Example 10 ◎ 8.0 0.19 29 Comparative Example 11 ◎ 8.0 0.18 27 Comparative Example 12 ◎ 8.0 0.21 26

As such, Comparative Examples 7 to 12 are performed by changing only the atmospheric conditions of the drying process performed after the bottom plating in Examples 7 to 9, and 13 to 15 of the present invention, as can be seen in Table 6, plating It can be seen that the plating properties such as the average adhesion strength and the flex resistance of the film are markedly inferior to those of the conductive metal plated polyimide substrates of Examples 1 to 3 of the present invention.

1 is a graph showing the average adhesion strength of the conductive metal plated polyimide substrate for COF of Examples 1, 7, 13, and Comparative Examples 1 to 12.

As can be seen in Figure 1, the process temperature is 150 ℃ (Comparative Examples 7 to 3) when the process temperature is set to room temperature (Comparative Examples 1 to 3) by setting the atmosphere of the drying process after the lower plating as an atmospheric atmosphere of oxygen and nitrogen. In the case of 9), when the process temperature is set at 200 ° C. (Comparative Examples 10 to 12), it can be seen that simply increasing the drying temperature does not increase the adhesion strength of the conductive metal plated polyimide substrate. This result shows that the adhesion strength increases in the case of the temperature increase from room temperature (Comparative Examples 1 to 3) to 150 ° C (Comparative Examples 7 to 9), but the higher temperature at which the process temperature is 200 ° C (Comparative Examples 10 to 12). In the case of an increase, it can be seen as a result of the decrease in the adhesive strength. This is thought to be because copper in the lower plating surface causes an oxidation reaction with oxygen in the atmosphere due to the rise in temperature.

On the other hand, Examples 1, 7, and 13 show a remarkable effect which cannot be anticipated from having only one temperature condition as a combination of temperature conditions and conditions under an inert atmosphere.

FIG. 2 is a graph showing changes in bending resistance of the conductive metal plated polyimide substrate for COF of Examples 1, 7, 13, and Comparative Examples 1 to 12 according to each process temperature and atmosphere. FIG.

As can be seen in Figure 2, when the process temperature is set to room temperature (Comparative Examples 1 to 3) by setting the atmosphere of the drying step after the lower plating as an atmospheric atmosphere of oxygen and nitrogen, the process temperature is 150 ℃ (Comparative Examples 7 to In the case of 9), when the process temperature is 200 ° C (Comparative Examples 10 to 12), it can be seen that simply increasing the drying temperature does not increase the flex resistance of the conductive metal plated polyimide substrate. This result shows that the bending resistance increases in the case of the temperature rise from room temperature (Comparative Examples 1 to 3) to 150 ° C (Comparative Examples 7 to 9), but the higher temperature at which the process temperature is 200 ° C (Comparative Examples 10 to 12). In the case of the rise, it can be seen as a result of the decrease in the flex resistance. This is considered to be because copper on the surface causes an oxidation reaction with oxygen in the atmosphere along with the temperature rise.

On the other hand, Examples 1, 7, and 13 show a remarkable effect which cannot be anticipated from having only one temperature condition as a combination of temperature conditions and conditions under an inert atmosphere.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the range of.

As described above, since the conductive metal plated polyimide substrate having the two-layer structure of the present invention does not use an adhesive layer, it has excellent plating property, adhesion strength, heat resistance, chemical resistance, crushing property, and bending resistance.

The conductive metal plated polyimide substrate having the two-layer structure of the present invention can realize a microcircuit, and thus can be used for COF for the purpose of mounting a drive drive, and the like. Antenna raw material of RFID or electromagnetic shielding of PDP It can be applied to products of various fields such as film for use. In addition, the FCCL of the two-layer structure of the present invention can greatly advance the feasibility of various methods such as a semi-additive method.

Claims (10)

In the method of manufacturing a conductive metal plated polyimide substrate having a two-layer structure, a) etching the polyimide membrane surface with an etching solution selected from the group consisting of KOH, ethylene glycol and KOH mixed solutions, NaOH, pyrrolidone and NaOH mixed aqueous solutions, or a mixture of chromic anhydride and sulfuric anhydride; b) adsorbing a catalyst on said polyimide membrane; c) a first plating step of forming a first conductive metal film without applying current to the polyimide film to which the catalyst is adsorbed; d) drying the first plated polyimide film for 5 to 30 minutes in an inert gas atmosphere within a temperature range of 110 ° C. to 200 ° C .; And e) A method of manufacturing a conductive metal plated polyimide substrate having a two-layer structure comprising a second plating step of applying a current to the dried first plated polyimide film to form a second conductive metal film. The method of claim 1, And the first conductive metal film is formed of gold, nickel or copper. The method of claim 1, The second conductive metal film is formed of gold or copper, conductive metal plated polyimide substrate manufacturing method having the two-layer structure. The method of claim 1, In step d), A method for producing a conductive metal plated polyimide substrate having the two-layer structure, wherein the inert gas is Ar gas. The method of claim 1, In step d), Method for producing a conductive metal plated polyimide substrate having a two-layer structure characterized in that for 5 to 30 minutes to dry within a temperature range of 150 ℃ to 200 ℃. The method of claim 1, In step c), A conductive metal plated polyimide substrate manufacturing method having the two-layer structure, characterized in that the catalyst is palladium or tin. The method of claim 1, Coupling the etched polyimide film surface with a coupling agent comprising a predetermined coupling agent. The method of claim 7, wherein And said coupling agent is a silane group or an amine group. The method of claim 7, wherein Wherein said coupling agent is a silane coupling agent containing aminopropyl triethoxy silane, an alkali based coupling agent comprising sodium oxide and monometalamine, or an acid based coupling agent comprising ethylene diamine and hydrochloric acid. A method for producing a conductive metal plated polyimide substrate having a structure. The method of claim 1, In one or more of the above steps, a method for producing a conductive metal plated polyimide substrate having the two-layer structure, characterized in that by applying an ultrasonic wave to the entire polyimide film to induce a continuous reaction.

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