TWI526304B - Thick layer polyimide metal clad laminate - Google Patents

Description

Thick layer of polyamidide metal coated laminate

[Cross-reference related application]

This application claims the priority of Korean Patent Application No. 10-2010-0101830 in Article 119 of the US Patent Law (corresponding to Article 27 of the Taiwan Patent Law). The aforementioned related application was filed with the Korean Patent Office on October 19, 2010. The application is filed and the disclosure of the case is fully incorporated herein by reference.

The present invention relates to a thick layer of polyamidimide metal coated laminate, and more particularly to a thick layer of polyamidimide metal coated laminate, wherein the polyimide film has a specific range of machinery And thermal properties for the manufacture of products with excellent process stability and excellent dimensional stability.

A flexible metal-clad laminate, which is a laminate of a conductive metal foil and an insulating polymer, which can be modified by microcircuit processing and can be bent in a narrow space. Therefore, as electronic devices are currently shrinking in size and weight, flexible metal coated laminates are increasingly used in a wide variety of applications. These flexible metal coated laminates can be classified into two-layer and three-layer types.

A three-layer type of metal-clad laminate is attached to an an adhesive layer using an epoxy-based or urethane-based adhesive layer. The imide film is fabricated with a metal foil. Under this condition, the heat resistance, the flame resistance, and the thermal stability are lowered due to the heat-labile adhesive layer, and the dimensional change is large after the etching and heat treatment processes. This can reduce the productivity of the manufacturing process of the printed circuit board. In order to overcome these disadvantages, a two-layer type flexible metal coated laminate without an adhesive layer was developed and used. There are two different methods for formulating a two-layer flexible metal-clad laminate having excellent heat resistance: a coating method and a lamination method. In the case of using the coating method, the flexible metal coated laminate is as described below. Made. A polyamic acid solution is applied to a conductive metal foil, and then a thermal cure is performed to transform the polylysine on the conductive metal foil to the polyimide. A thermoplastic polyimine layer is introduced into the outermost layer of polyimide layer as needed, and then the metal foil is laminated to prepare a double-sided metal-clad laminate. In the case of using the lamination method, a thermoplastic polyimide layer is formed on one side or both sides of a polyimide film, and then a metal foil is attached to prepare a single-sided or double-sided metal package. Covering the laminate.

When a metal-clad laminate having a thick polyimine layer is produced by a coating method, problems such as the appearance of foaming may occur on the surface or at the interface between the polyimide layers. In addition, mechanical strength and chemical resistance are lowered by the reduced degree of curing of polyamic acid. The dimensional stability is also reduced due to the difficulty in removing the solvent remaining in the film.

In order to overcome the above deficiency, a thick layer of polyimide polyimide coated laminate having a thick polyimine layer can be produced by a laminate method. The inventors of the present invention found the appearance (creases, oblique lines, longitudinal stripes, or the like) of two layers of flexible copper-clad laminates prepared by a laminate method and dimensional stability. problem. In order to solve these problems, the inventors of the present invention conducted various studies and finally completed the present invention.

The present invention is directed to providing the mechanical and thermal properties of a polyimide film which is required to produce a metal coated laminate of a thick polyimide layer having good appearance and mechanical properties by a laminate process.

The present invention is directed to providing a metal coated laminate having a thick polyimine layer. The inventors of the present invention have found that when a thick layer of polyimide polyimide coated laminate having a thick polyimine layer is prepared by a lamination method, the mechanism of the polyimide film for the core layer of the polyimide layer is laminated. The thermal characteristics should have a specific range to achieve excellent process stability and dimensional stability, and further complete the present invention.

The thick layer of polyimide metal coated laminate according to the present invention can be formulated by a lamination method. In this case, the appearance of the product occurs after the lamination process (example Improvements such as wrinkles, diagonal lines, longitudinal bands, or the like can be obtained, and the metal-coated laminates have excellent dimensional stability.

In particular, the present invention is directed to providing a single-sided (ie, one-side metal foil on a polyimide film) or a double-sided (that is, a metal foil coated on a polyimide film on both sides) using a laminate method. A method for producing a thick layer of polyimide-coated metal-clad laminate.

Here, the polyimide laminate comprises a thermoplastic polyimide layer formed on one or both sides of the core polyimide film, and the core polyimide film has: 30% or Lower elongation; tensile modulus of 3 GPa or higher, measured by the IPC-TM-650 (2.4.19) method; and a coefficient of thermal linear expansion (CTE) of 5 to 30 ppm/°C, Calculated to 250 ° C at 100 ° C.

The present invention can improve the appearance defects occurring after the lamination process by setting the range of mechanical and thermal properties of the core polyimide film, and furthermore, the present invention discovers the thick layer of polyimide polyimide coated laminate. The dimensional stability is improved and is completed.

In other words, the present invention is characterized in that the core polyimine film has an elongation of 30% or less; a tensile modulus of 3 GPa or more, which is measured by the IPC-TM-650 (2.4.19) method; And a coefficient of thermal linear expansion (CTE) of 5 to 30 ppm/° C., which is calculated from 100 ° C to 250 ° C. The present invention has been accomplished by, as long as the above range is satisfied, a thick layer of polyimide-coated metal-clad laminate can be produced by a laminate method, and the metal-clad laminate having excellent dimensional stability can be produced.

In the present invention, when the polyimide film has an elongation of 30% or less, more specifically, an elongation of 25% or less, and more preferably in the range of 5 to 30%, via a laminate The polyimine film can be laminated to a metal foil. When it exceeds 30%, a flare phenomenon may occur, and thus a defect in appearance such as a longitudinal belt, wrinkles, or the like may occur on the product after the lamination method, resulting in failure to manufacture a product having a better appearance.

Further, the polyimide film of the present invention has a tensile modulus of 3 GPa or more, more specifically, a tensile modulus of 4 GPa or more, and more preferably a tensile modulus of 4 to 8 GPa. If the polyimide film has a tensile modulus of less than 3 GPa, appearance defects may occur after the lamination process because the polyimide film has a soft property and a high elongation as described above.

When the polyimine film of the present invention has a thermal linear expansion coefficient (CTE) of 5 to 30 ppm/° C., and more preferably 10 to 25 ppm/° C., which is calculated from 100° C. to 250° C., can be produced. A metal coated laminate with excellent dimensional stability. If it exceeds 30 ppm/° C. or less than 5 ppm/° C., the difference in CTE between the polyimide film and the metal foil (especially copper foil) becomes large, thus increasing the dimensional change after etching and heat treatment.

In order to produce a thick layer of polyimide-coated metal-clad laminate, the polyimide film preferably has a thickness of 25 μm or more, and particularly a thickness of 25 to 150 μm.

In the present invention, the polyimide polyimide laminate is prepared by coating a thermoplastic poly-polyamine on one or both sides of the core polyimide film, followed by drying and heat treatment. In the present invention, the lamination process means that a conductive metal foil is attached to the polythene laminate by a high temperature lamination method. Here, the conductive metal foil may be disposed on one side or both sides of the polyimide laminate.

Here, the conductive metal foil may be a copper foil, a stainless foil, an aluminum foil, a nickel foil, an alloy foil of two or more metals, or the like, but the conductive metal is provided as long as the target conditions sought in the present invention are satisfied. The type of foil is not limiting. Similarly, the thickness of the conductive metal foil is not limited, but it is preferably 9 to 70 μm in order to obtain good workability.

The polyimide film as the core layer may be subjected to surface treatment, for example, corona treatment, plasma treatment, or the like to enhance the adhesion strength to the thermoplastic polyimide layer, but as long as the invention is satisfied The target conditions sought, the surface treatment method is non-limiting. These surface treatment methods can be used to increase the roughness or to change the chemical structure of the surface layer of the polyimide film.

The method for formulating the thermoplastic polyimide layer in the present invention is not particularly limited. In the present invention, a polyglycine solution, which is a precursor of a thermoplastic polyimine, is coated on one or both sides of the core polyimide film. After drying and heat treatment, a thermoplastic polyimine layer is formed on the core polyimide film. A method which can be used for coating a polyaminic acid solution on a polyimide film includes knife coating, roll coating, die coating, curtain coating And the like, but the coating method is not limited as long as the target conditions sought by the present invention are satisfied.

In the present invention, a polyaminic acid solution as a polyimide precursor is coated and dried, and then subjected to a thermal or chemical imidization procedure to convert the poly-proline to polyphthalamide. amine. Any heat treatment method may be applied to the heat treatment method of the present invention, but the heat treatment method is generally carried out by forming a colloid by coating and drying a portion of the ruthenium iodide resin or the polyimide precursor resin. Membrane, and then the gel film is fixed in a drying oven for a predetermined time or continuously to transport the colloidal film into the drying oven for a predetermined period of time. The heat treatment temperature is usually 300 ° C or higher, and it is preferred to carry out a high temperature treatment of 300 to 500 ° C. Any known heating method can be applied as a method of heat treatment as long as the target conditions sought in the present invention can be satisfied.

For the thermoplastic polyimine and the thermoplastic polyphthalic acid used in the present invention, the glass transition temperature (Tg) is 180 ° C or higher, and the preferred condition is 200 to 300 ° C. This temperature is measured after complete hydrazine imidization. In the present invention, any thermoplastic polyimine resin or polyglycine solution having thermoplastic properties can be used, and in particular, the kind thereof is not limited.

Further, the thickness of the thermoplastic polyimide layer after the final curing process may be 3 to 20 μm, and the thickness range is a preferable condition since the adhesion strength to the metal foil and the manufacturing stability can be stably obtained.

In the present invention, the temperature of the build-up process is not particularly limited, but it is preferably heated to exceed the glass transition temperature of the thermoplastic polyimide. When the heating temperature is insufficient, the thermoplastic polyimide layer does not have sufficient fluidity in the lamination process to conform to the metal foil, and thus a stable adhesive strength cannot be obtained. The temperature of the build-up process is generally preferably higher than the glass transition temperature (Tg) of the thermoplastic polyimine from 30 to 200 °C. Further, the pressure of the lamination process is preferably a linear pressure of 50 to 200 kgf/cm. When the pressure is high, the temperature of the lamination process can be lowered, and therefore, it is necessary to use as high a pressure as possible to achieve high productivity.

Other features and aspects will be apparent from the following detailed description, drawings, and claims.

The invention will be described in detail below by way of examples, but the invention is not limited to the following examples.

Appearance assessment

The appearance defects occurring in the present invention after the lamination process are confirmed by the naked eye. The flare phenomenon or flairs phenomenon is a phenomenon in which a film is in contact with a high-temperature laminator roll, which is deformed like a wave shape. When the wavy deformation phenomenon occurs on the film, wrinkles (wrinkles) may occur on the copper foil after lamination by copper foil. The formation of these wrinkles depends on the degree of wavy deformation of the polyimide laminate. When the wavy deformation occurs, the degree of wavy deformation is evaluated according to the following criteria.

"○" indicates that there is a large wave-like deformation phenomenon, and these wavy deformations form wrinkles after passing through the laminating rolls. "△" indicates a weak wavy deformation phenomenon, but wrinkles were not formed after passing through the laminating roller. "x" indicates high processing stability without causing wavy deformation. When wrinkles are formed on the product after the lamination process, the product is judged by the scores ○, Δ, and x according to the degree of wrinkles.

The mechanical and thermal properties described in the present invention are based on the following measurement methods.

2. Mechanical properties

Mechanical properties were measured by the method of IPC-TM-650, 2.4.19. Samples for measurement of tensile strength and elongation were placed, and then tensile strength and elongation of each sample were measured using a universal testing machine (UTM). Thereafter, a tensile modulus is calculated based on the measurement results.

3. Measurement of coefficient of thermal linear expansion (CTE)

The thermal linear expansion coefficient is obtained by raising the temperature to 400 ° C at a rate of 5 ° C / min, and measuring the thermal expansion value between 100 ° C and 250 ° C by a thermomechanical analyzer (TMA). Averaged.

4. Size change after etching and after heat treatment

This measurement is based on Method B of IPC-TM-650, 2.2.4. Position recognition holes were drilled at the four vertices of the rectangular sample, and the MD and TD of the rectangle were 275 mm x 255 mm, respectively. The sample was stored in a chamber at 23 ° C and 50% RH for 24 hours. Next, the distance between the holes is measured three times in succession, and then the measured distance is averaged. Next, after the copper foil was completely etched, and the etched sample was stored in the chamber at 23 ° C and 50% RH conditions for 24 hours, the distance between the holes was measured. The dimensional change after etching was obtained by comparing the distances of the copper foil in the MD and TD directions before and after etching. After this measurement, the sample was heat treated at 150 ° C for 30 minutes, and then the sample was stored in a chamber at 23 ° C and 50% RH for 24 hours. Next, measure the distance between the holes. Comparing the distance measured above with the distance of the hole of the original sample, the dimensional change of MD and TD after heat treatment can be calculated.

The abbreviations used in the following configuration examples are as follows:

- DMAc: N,N-dimethylacetamide

- BPDA: 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (3,3',4,4'-biphenyltetracarboxylic acid dianhydride)

- BTDA: 3,3',4,4'-benzophenonetetracarboxylic dianhydride (3,3',4,4'-benzophenonetetracarboxylic dianhydride)

- PDA: p-phenylenediamine

- ODA: 4,4'-diaminodiphenylether (4,4'-diaminodiphenylether)

- TPER: 1,3-bis(4-aminophenoxy)benzene

[Preparation Example 1]

By stirring in a 2006 g DMAc solution under nitrogen atmosphere, 119.06 g of TPER and 14.68 g of PDA diamine were all dissolved, and then 95.88 g of BPDA and 70 g of BTDA, which were added as dianhydride, were added thereto. The operation was carried out in three steps. The polyamic acid solution was prepared by stirring for 24 hours. The polyamic acid solution was coated to prepare a film, and the temperature was raised to 350 ° C for 60 minutes during 60 minutes. The film has a thickness of 20 μm after heat curing. The measured glass transition temperature was 223 °C.

[Preparation Example 2]

49.7 g of TPER and 102.1 g of ODA diamine were all dissolved in 2425 g of DMAc solution under nitrogen atmosphere, and 200 g of BPDA, which is a dianhydride, was added thereto, and the addition was carried out in three portions. The polyamic acid solution was prepared by stirring for 24 hours. The polyamic acid solution was coated to prepare a film, and the temperature was raised to 350 ° C for 60 minutes during 60 minutes. The film has a thickness of 20 μm after heat curing. The measured glass transition temperature was 236 °C.

[Preparation Example 3]

90.7 g of TPER and 33.55 g of PDA diamine were all dissolved by stirring in 2112 g of DMAc solution under nitrogen atmosphere, and then 91.3 g of BPDA and 100 g of BTDA, which were added as dianhydride, were added thereto. The operation was carried out in three steps. The polyamic acid solution was prepared by stirring for 24 hours. The polyamic acid solution was coated to prepare a film, and the temperature was raised to 350 ° C for 60 minutes during 60 minutes. The film has a thickness of 20 μm after heat curing. The measured glass transition temperature was 252 °C.

The mechanical properties, thickness and CTE of the core polyimine film used in the present invention in the MD/TD direction are shown in Table 1.

[Example 1]

The polyaminic acid solution prepared in Formulation Example 2 was applied to both sides of the plasma-treated polyimide film (A) having a thickness of 38 μm. The thickness of the coated ruthenium polyamine on one side of the polyimide film was determined by the final thickness after thermal curing of the polyimide film, which was 6 μm. After coating the crucible, the polylysine film on the polyimide film was formed by hot-air drying in a chamber at 130 °C.

The polylysine film was transformed into a thermoplastic polyimide film via a thermal imidization process. The enthalpy imidization process was carried out by raising the temperature from 150 ° C to 395 ° C at 9 ° C for 9 minutes at a rate of 20 ° C/min.

Thereafter, the thermoplastic polyimide-coated polyimide film was inserted between ED (electrodeposited) copper foils having a thickness of 12 μm. The double-sided metal-clad laminate is produced by bonding the ED copper foil to the thermoplastic polyimide-coated polyimide film by a high-temperature heat lamination method at a pressure of 100 kgf/cm. side.

[Example 2]

A double-sided metal-clad laminate was produced by performing the same process as in Example 1 except that a rolled (RA, roll and annealed) copper foil having a thickness of 18 μm was used.

[Example 3]

A double-sided metal-clad laminate was produced, except that a rolled copper foil having a thickness of 18 μm and a polyamic acid solution prepared in Formulation Example 1 were used, by performing the same process as in Example 1.

[Example 4]

A double-sided metal-clad laminate was produced except that a polyimine film (B) having different mechanical properties and thermal properties as compared with the polyimide film used in Example 1 was used, and a thickness of 18 μm was used. The same process as in Example 1 was carried out except for the electrodeposited copper foil.

[Example 5]

A double-sided metal-clad laminate was produced except that a rolled copper foil having a thickness of 12 μm and a polyamic acid solution prepared in Formulation Example 3 were used, by performing the same process as in Example 4.

[Example 6]

A double-sided metal-clad laminate was produced by using a polyimine film (C) having different mechanical properties and thermal properties than the polyimide film used in Example 1 Execute the same process as Example 1.

[Example 7]

A double-sided metal-clad laminate was produced by using a polyimine film (D) having different mechanical properties and thermal properties than the polyimide film used in Example 1 Execute the same process as Example 1.

[Example 8]

The polyaminic acid solution prepared in Formulation Example 1 was applied to both sides of the plasma-treated polyimine film (E) having a thickness of 50 μm. The thickness of the coated phthalocyanine on one side of the polyimide film was determined by the final thickness after thermal curing of the polyamic acid film, which was 3 μm. After coating the crucible, the polylysine film on the polyimide film was formed by hot air drying in a drying chamber at 130 °C.

The polyamic acid film is converted into a thermoplastic polyimide film via a hot hydrazine imidization process. The enthalpy imidization process was carried out by raising the temperature from 150 ° C to 395 ° C at 9 ° C for 9 minutes at a rate of 20 ° C/min.

Thereafter, the thermoplastic polyimide-coated polyimide film was inserted between electrodeposited (ED) copper foils having a thickness of 35 μm. The double-sided metal-clad laminate is prepared by laminating the ED copper foil on both sides of the thermoplastic polyimide-coated polyimide film by a high-temperature heat lamination method at a pressure of 100 kgf/cm. .

[Example 9]

A double-sided metal-clad laminate was prepared by performing the same process as in Example 8 except that an electrodeposited (ED) copper foil having a thickness of 12 μm was used.

[Example 10]

A double-sided metal-clad laminate was produced, except that a rolled copper foil having a thickness of 18 μm was used, by performing the same process as in Example 8.

[Comparative example 1]

A double-sided metal-clad laminate was produced, except that a polyimine film (F) having a thickness of 50 μm having different mechanical properties and thermal characteristics as compared with the polyimide film used in Example 8 was used. The same process as in Example 8 was carried out, except that a rolled copper foil having a thickness of 35 μm was used.

[Comparative example 2]

A double-sided metal-clad laminate was produced, except that a polyimine film (G) having a thickness of 50 μm having different mechanical properties and thermal characteristics as compared with the polyimide film used in Example 8 was used. The same process as in Example 8 was carried out, except that a rolled copper foil having a thickness of 12 μm was used.

Table 2 shows the appearance defects and dimensional stability that occurred when a thick layer of polyimide polyimide coated laminate was produced using each of the polyimide films of Table 1.

As shown in Table 2, when the mechanical and thermal properties of the core polyimide film have a specific range as stipulated by the present invention, a high quality metal coated laminate can be formulated by the lamination method. That is, when the polyimide film has an elongation of 30% or less, a tensile modulus of 3 GPa or more, and a thermal linear expansion coefficient (CTE) of 5 to 30 ppm/° C (calculated from 100 ° C) At 250 ° C), a metal foil can be laminated by a laminate method. Further, it can be observed that when the tensile modulus is 4 GPa or more and the elongation is 25% or less, the process stability can be further improved, and excellent dimensional stability can be obtained.

However, as shown in Comparative Examples 1 and 2, it can be observed that when the elongation, the tensile modulus, and the thermal linear expansion coefficient deviate from the range of the present invention, the lamination method cannot be applied to prepare a thick layer of polyimide metal. The laminate is coated because of a wavy deformation in the lamination process, and thus appearance defects such as longitudinal bands, wrinkles, or the like occur on the product after the lamination process.

Therefore, mechanical properties can be observed, in particular, the elongation, tensile modulus, and CTE value of the polyimide film as the core layer must have an appropriate range to produce a metal having excellent process stability and dimensional stability. Cover the laminate.

The present invention proposes a mechanical and thermal property of a polyimide film as a core layer for manufacturing a process stability in a process for producing a thick metal-clad laminate having a thick polyimine layer by a build-up method. Sex and dimensional stability products. According to the present invention, a process problem which may occur when a thick metal clad laminate is produced by the lamination method can be minimized, and a thick metal clad laminate having excellent characteristics can be manufactured.

Claims (9)

A thick layer of polyimine metal coated laminate, wherein a laminate of a polyimide and a metal foil is laminated on one side or two of the polyimide layer by a lamination process a side, wherein the polyimine laminate comprises a polyimine film, and a thermoplastic polyimine layer formed on one or both sides of the polyimide film, the poly The amine film has an elongation of 30% or less; a tensile modulus of 3 GPa or higher, the tensile modulus is measured by the IPC-TM-650 (2.4.19) method; and 5 to A coefficient of thermal linear expansion (CTE) of 30 ppm/° C., calculated from 100 ° C to 250 ° C, wherein the polyimide film has a thickness of 25 μm to 150 μm. A thick-layered polyimide metal-clad laminate according to claim 1, wherein the polyimide film has an elongation of 25% or less; a tensile modulus of 4 GPa or more; And a coefficient of thermal linear expansion (CTE) of 10 to 25 ppm/°C. A thick-layered polyimide metal-clad laminate according to claim 1, wherein the metal foil is selected from the group consisting of copper foil, stainless foil, aluminum foil, nickel foil, and alloy foil of two or more metals. The thick polytheneimide metal coated laminate according to claim 1, wherein the thermoplastic polyimide layer is obtained by coating and drying a polyamine resin solution to form a colloid. The film is then placed in the drying oven or a heat treatment is performed on the colloidal film. A thick layer of polyimide polyimide coated laminate according to claim 4, wherein the thermoplastic polyimide layer has a glass transition temperature of from 180 to 300 °C. A thick layer of polyimide polyimide coated laminate according to claim 4, wherein the thermoplastic polyimide layer has a thickness of from 3 to 20 μm after final curing. A thick-layered polyimide metal-clad laminate according to claim 1, wherein in the lamination process, a thermal lamination method is applied to the thermoplastic polyimide layer of the thermoplastic polyimide layer. Conversion temperature or higher. A thick-layered polyimide metal-clad laminate according to claim 7, wherein the thermal conversion layer is subjected to a glass transition temperature of 30 of a thermoplastic polyimine resin higher than the thermoplastic polyimide layer. To a temperature of 200 ° C. A thick layer of polyimide polyimide coated laminate according to claim 7 wherein the heat lamination method is carried out at a pressure of 50 to 200 kgf/cm.