KR101614847B1 - Flexible metal laminate - Google Patents

Abstract

The present invention relates to a flexible metal clad laminate comprising first and second polyimide resin layers containing a fluorine resin in different contents.

Description

[0001] FLEXIBLE METAL LAMINATE [0002]

The present invention relates to a flexible metal laminate, and more particularly, to a flexible metal laminate capable of securing an optimized thermal expansion coefficient with high elasticity while having a low dielectric constant.

In recent years, signal transmission speed within the electronic device or signal transmission speed to the outside of the electronic device has been accelerating in accordance with the trend of miniaturization and high speed of electronic devices and the combination of various functions. Accordingly, a printed circuit board using an insulator having a dielectric constant and a dielectric loss coefficient lower than that of an existing insulator is required.

As reflected in this tendency, there is a tendency to apply LCP (Liquid Crystalline Polymer), which is an insulator less susceptible to moisture absorption, than a conventional polyimide even in a flexible printed circuit board. However, even when the LCP is applied, the degree of improvement due to application is insignificant because the dielectric constant (Dk = 2.9) of LCP is substantially not different from that of polyimide (Dk = 3.2) substantially and the heat resistance of the LCP becomes a problem in the soldering process And since the LCP has thermoplasticity, there is a problem that compatibility with the PCB manufacturing process using the conventional polyimide is inferior in the laser hole processing using the laser.

Accordingly, efforts have been made to lower the dielectric constant of polyimide used as an insulator of conventional flexible circuit boards. For example, U.S. Patent No. 4,816,516 discloses a method of molding a molded article by mixing polyimide and a fluorine-based polymer. However, the above patent does not relate to a product for an electronic device requiring a low dielectric constant but relates to a molded product, and polyimide having a large coefficient of thermal expansion and a low glass transition temperature is used. In addition, in order to be used for a printed circuit board, a polyimide resin must be processed in the form of a thin film. The US patent does not disclose a thin-film-type copper-clad laminate.

Further, U.S. Patent No. 7026032 discloses a method of lowering the dielectric constant of a product produced by dispersing a fine powder of a fluorine-based polymer in polyimide. The US patent discloses that the fluorine-based polymer fine powder is more distributed on the outer surface than the inner core of the insulator. However, since the content of the fluorinated polymer is large in the outermost layer of the insulator as described in the above-mentioned U.S. patent, moisture permeation and absorption are lowered by the fluorinated polymer on the outer surface, and the overall water absorption rate can be lowered. However, There is a problem that the copper clad laminate does not exist. For example, the polyimide resin described in the U.S. patent may weaken the adhesive force with the coverlay or the adhesion with the prepreg, and the adhesive force with the ACF may be lowered, and the coefficient of thermal expansion (CTE) of the polyimide resin disclosed in the above- Since the fluoropolymer is present in excess on the surface of the polyimide resin, the fluoropolymer can be melted at a temperature of about 380 ° C, which is applied to the holding process during the PCB manufacturing process There is a risk that the copper foil circuit will peel off from the insulator.

On the other hand, although the permittivity can be lowered to a certain degree by adding a fluorine resin to a polymer material applied to a field of a printed circuit board and the like, the higher the fluorine resin content is, the more the polymer material itself becomes brittle, . Accordingly, it is necessary to develop a polyimide material having a low dielectric constant and a high coefficient of elasticity with a low thermal expansion coefficient using a fluorine resin.

U.S. Patent No. 4,816,516 U.S. Patent No. 7026032

An object of the present invention is to provide a flexible metal laminate capable of securing an optimized thermal expansion coefficient with a high dielectric constant and a low dielectric constant.

In the present specification, a first polyimide resin layer containing 0% by weight to 20% by weight of a fluorine resin; And a second polyimide resin layer containing 20 to 70% by weight of a fluorine-based resin, wherein the second polyimide resin layer contains a fluorine-based resin in a proportion of a proportion of the fluorine-based resin contained in the first polyimide resin layer Based resin is at least 10% by weight, based on the total weight of the fluorine-containing resin.

The flexible metal laminate according to a specific embodiment of the present invention will be described in more detail below.

As described above, according to one embodiment of the present invention, there is provided a polyimide resin composition comprising: a first polyimide resin layer containing 0 to 20% by weight of a fluorine resin; And a second polyimide resin layer containing 20 to 70% by weight of a fluorine-based resin, wherein the second polyimide resin layer contains a fluorine-based resin in a proportion of a proportion of the fluorine-based resin contained in the first polyimide resin layer Based resin is 10% by weight or more higher than that of the fluorine-containing resin.

The present inventors have found that a soft metal laminate including two kinds of polyimide resin layers containing a fluorine resin in different contents can secure a low dielectric constant and can greatly improve the elasticity of the polymer resin layer contained therein, We have confirmed through experiments that we have a coefficient and have completed the invention.

In the past, a method of adding a fluorine-based polymer resin to lower the dielectric constant of a polymer resin such as polyimide applied to a soft metal laminate is known, but a typical fluorine resin such as polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluor The thermal expansion coefficients of the propylene copolymer (FEP) and the perfluoroalkoxy (PFA) are 135 ppm, 150 ppm and 230 ppm, respectively, which are considerably larger than the thermal expansion coefficient of 10 to 30 ppm of the conventional polyimide and sufficiently lower the permittivity of the polyimide It is necessary to add about 10 to 60 wt% of the above-mentioned fluororesin, so that the overall thermal expansion coefficient has to be increased. Further, as the content of the fluororesin in the polymer resin layer containing the polyimide and the fluororesin increases, the elongation of the polymer resin layer is significantly lowered and the elasticity required in the fluororesin is not satisfied.

On the contrary, the flexible metal laminate of one embodiment includes at least one first polyimide resin layer containing a relatively small amount of a fluorine-based resin and at least one second polyimide resin layer containing a relatively large amount of a fluorine-based resin, The content of the fluororesin in the first polyimide resin layer and the content of the fluororesin in the second polyimide resin layer is at least 10% by weight, so that the content of the fluororesin is increased to lower the permittivity of the flexible metal laminate of one embodiment A high elasticity can be secured.

This is because the first polyimide resin layer and the second polyimide resin layer contain different amounts of the fluorine resin, the first polyimide resin layer having a small content of the fluorine resin maintains a relatively high elasticity and elongation as much as possible , And protects the second polyimide resin layer having relatively low elasticity and elongation.

The content ratio of the fluororesin contained in the second polyimide resin layer may be higher than that of the fluororesin included in the first polyimide resin layer by at least 10% by weight. Specifically, the first polyimide resin layer And the second polyimide resin layer may be 10 wt% to 70 wt%, or 20 wt% to 60 wt%, respectively.

If the difference in the content ratio of the fluorine resin contained in each of the first polyimide resin layer and the second polyimide resin layer is too small, the effect of improving the elasticity and elongation of the flexible metal laminate may be insignificant.

The flexible metal laminate may include at least one of the first polyimide resin layer and the second polyimide resin layer.

The ratio of the total thickness of the second polyimide resin layer to the total thickness of the first polyimide resin layer may be 0.1 to 5.0, or 0.3 to 3, or 0.5 to 2. If the total thickness of the first polyimide resin layer is too thin, the effect of improving the elasticity and elongation may be insignificant. If the entire first polyimide resin layer having a relatively small content of the fluorine resin is too thick, the content of the fluorine resin contained in the flexible metal laminate becomes low, and it becomes difficult to secure a low dielectric constant.

On the other hand, in the flexible metal laminate, the average content of the fluorine resin defined by the following general formula 1 may be 10 wt% to 50 wt%, or 15 wt% to 40 wt%.

[Formula 1]

The sum of the fluoric resin average content = [(the content ratio of the fluororesin contained in the first polyimide resin layer * the thickness of the first polyimide resin layer) + (the total amount of the fluororesin contained in the second polyimide resin layer Content ratio * total thickness of the second polyimide resin layer)] / (total thickness of the first polyimide resin layer and the second polyimide resin layer)

If the average content of the fluorine-based resin defined by the general formula 1 in the flexible metal laminate of one embodiment is too low, the dielectric constant of the flexible metal laminate may be greatly increased, and if the average content of the fluorine- The elongation of the soft metal laminate may be significantly reduced or the thermal expansion coefficient may be greatly increased.

The soft metal laminate of one embodiment has a higher elongation and a lower thermal expansion than the soft metal laminate using a polyimide resin layer having the same average content of the fluorine-based resin having the same average composition as the above-mentioned formula Coefficient, so that it is possible to realize higher performance and higher reliability.

On the other hand, the fluorine resin contained in each of the first polyimide resin layer and the second polyimide resin layer may be at least one selected from the group consisting of polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) Tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene copolymer resin (ETFE), tetrafluoroethylene-chlorotrifluoroethylene copolymer (TFE / CTFE) and ethylene-chlorotrifluoro And ethylene resin (ECTFE).

The fluororesin may be a particle having a longest diameter of 0.05 mu m to 20 mu m, or 0.1 mu m to 10 mu m. If the maximum diameter of the fluororesin is too small, the surface area of the fluororesin increases, and the physical properties of the first polyimide resin layer and the second polyimide resin layer may be lowered. In addition, if the maximum diameter of the fluorine resin is too large, the surface characteristics of the first polyimide resin layer and the second polyimide resin layer to be produced may be lowered.

On the other hand, each of the first polyimide resin layer and the second polyimide resin layer may have a thickness of 0.1 mu m to 100 mu m, or 1 mu m to 50 mu m.

Each of the first polyimide resin layer and the second polyimide resin layer may include a polyimide resin having a weight average molecular weight of 5,000 to 500,000.

If the weight average molecular weight of the polyimide resin is too small, it is impossible to sufficiently secure the mechanical properties required in the application of the flexible metal laminate or the like. In addition, if the weight average molecular weight of the polyimide resin is too large, the elasticity and mechanical properties of the polyimide resin layer may be deteriorated.

Further, each of the first polyimide resin layer and the second polyimide resin layer may include a polyimide resin containing a repeating unit represented by the following formula (1).

[Chemical Formula 1]

In the above formula (1), Y ₁ is a tetravalent aromatic organic functional group, and X is a divalent aromatic organic functional group.

The Y ₁ may include a tetravalent functional group selected from the group consisting of the following formulas (21) to (27).

[Chemical Formula 21]

[Chemical Formula 22]

In Formula 22, Y ₁ represents a single bond, -O-, -CO-, -S-, -SO ₂ -, -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, -CONH-, _{-COO-, - (CH 2) n1} -, -O (CH 2) n2 O-, or -OCO (CH _{2) n3} a OCO-, wherein n1, n2 and n3 is an integer of 1 to 10, respectively.

 (23)

Y ₂ and Y ₃ may be the same or different and each represents a single bond, -O-, -CO-, -S-, -SO ₂ -, -C (CH ₃ ) ₂ -, -C _{(CF 3) 2 -, -CONH-} , -COO-, - (CH 2) n1 - _{a, -O (CH 2) n2 O-} , or -OCO (CH _{2) n3} OCO-, wherein n1, n2, and and n3 is an integer of 1 to 10, respectively.

≪ EMI ID =

In the above formula (24), Y ₄ , Y ₅ And Y ₆ may be the same or different from each other, and respectively a single bond, -O-, -CO-, -S-, -SO 2 -, -C (CH 3) 2 -, -C (CF 3) 2 -, _{a, -O (CH 2) n2 O-} , or -OCO (CH _{2) n3} a OCO-, wherein n1, n2 and n3 is 1 to 10 - -CONH-, -COO-, - (CH 2) n1 It is an integer.

(25)

(26)

(27)

In the above Formulas 21 to 27, '*' means a bonding point.

In order that the polyimide resin layer has a lower dielectric constant and a lower water absorption rate, but also has a high elasticity and an optimized thermal expansion coefficient, it is preferable that Y ₁ in the formula ₁ is a tetravalent group selected from the group consisting of the following formulas Functional group. The Y ₁ may be the same or different in each of the repeating units of the formula (1).

(28)

[Chemical Formula 29]

(30)

In the above Chemical Formulas 28 to 30, '*' means a bonding point.

In the above formula (1), X may be a divalent functional group selected from the group consisting of the following formulas (31) to (34).

(31)

Wherein R ₁ is selected from the group consisting of hydrogen, -CH ₃ , -CH ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ CH ₃ , -CF ₃ , -CF ₂ CF ₃ , -CF ₂ CF ₂ CF ₃ , CF ₂ CF ₂ CF ₂ CF ₃ Lt; / RTI >

(32)

Wherein L ₁ is a single bond, -O-, -CO-, -S-, -SO ₂ -, -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, -CONH-, _{-COO-, - (CH 2) n1} -, -O (CH 2) and _{n2 O-, -OCH 2 -C (CH} 3) 2 -CH 2 O- , or -OCO (CH _{2) n3} OCO-, wherein n1, n2 and n3 is an integer from 1 to 10, R ₁ and R ₂ may be the same or different from one another, each _{hydrogen, -CH 3, -CH 2 CH 3} , -CH 2 CH 2 CH 2 CH 3, -CF _3, -CF ₂ CF _3, it may be -CF ₂ CF ₂ CF _3, or _{-CF 2 CF 2 CF 2 CF 3} .

(33)

L ₂ and L ₃ may be the same or different and each represents a single bond, -O-, -CO-, -S-, -SO ₂ -, -C (CH ₃ ) ₂ -, -C _{(CF 3) 2 -, -CONH-} , -COO-, - (CH 2) n1 -, -O (CH 2) n2 O-, -OCH 2 -C (CH 3) 2 -CH 2 O- or - a OCO (CH _{2) n3} OCO-, wherein n1, n2 and n3 is an integer from 1 to 10, R _1, R ₂ and R ₃ may be the same or different from one another, each hydrogen, -CH _3, -CH ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ CH ₃ , -CF ₃ , -CF ₂ CF ₃ , -CF ₂ CF ₂ CF ₃ , or -CF ₂ CF ₂ CF ₂ CF ₃ Lt; / RTI >

(34)

In the above formula (34), L ₄ , L ₅ And L ₆ may be the same or different from each other, and respectively a single bond, -O-, -CO-, -S-, -SO 2 -, -C (CH 3) 2 -, -C (CF 3) 2 -, _{-CONH-, -COO-, - (CH 2} ) n1 -, -O (CH 2) n2 O-, -OCH 2 -C (CH 3) 2 -CH 2 O- , or -OCO (CH _{2) n3} OCO -, and wherein n1, n2 and n3 is an integer from 1 to 10, R _1, R _2, R ₃ and R ₄ may be the same or different from one another, each _{hydrogen, -CH 3, -CH 2 CH 3} , -CH ₂ CH ₂ CH ₂ CH ₃ , -CF ₃ , -CF ₂ CF ₃ , -CF ₂ CF ₂ CF ₃ , or -CF ₂ CF ₂ CF ₂ CF ₃ Lt; / RTI >

Particularly, when X in the above formula (1) is a divalent functional group of the following formula (35), the polyimide resin layer can have a lower dielectric constant and a lower water absorption rate, and also can secure an optimized thermal expansion coefficient with high elasticity . X may be the same or different in each of the repeating units of the formula (1).

 (35)

In the above formula (35), R ₁ and R ₂ may be the same or different from each other and each represents -CH ₃ , -CH ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ CH ₃ , -CF ₃ , -CF ₂ CF ₃ , -CF ₂ CF ₂ CF ₃ , -CF ₂ CF ₂ CF ₂ CF ₃ Lt; / RTI >

The flexible metal laminate may include at least one metal thin film including at least one selected from the group consisting of copper, iron, nickel, titanium, aluminum, silver, gold, and two or more alloys thereof.

Specifically, the flexible metal laminate may include one metal thin film, and the soft metal laminate may include two metal thin films opposed to each other. In this case, the first polyimide resin layer and / And the second polyimide resin layer may be positioned between the two metal films facing each other.

The ten point average roughness Rz of the surface of the metal thin film may be 0.5 탆 to 2.5 탆. If the 10-point average roughness of the surface of the metal thin film is too small, the adhesion to the polyimide resin layer or the porous polymer resin layer may be lowered. If the 10-point average roughness of the surface of the metal thin film is too large, The transmission loss may become large.

The metal thin film may have a thickness of 0.1 탆 to 50 탆.

According to the present invention, it is possible to provide a flexible metal laminate capable of securing an optimized thermal expansion coefficient with a high dielectric constant and a low dielectric constant.

Accordingly, it is an object of the present invention to provide a solution to increase the loss rate of data caused by an increase in the data transmission rate of a device such as a notebook computer, a computer, a mobile phone, or the like to increase the thickness of a printed circuit board, There is provided a method of manufacturing a low dielectric constant polyimide having characteristics of high heat resistance, chemical resistance, dimensional stability and the like, which is possessed by a conventional polyimide insulator while having a low dielectric constant.

A method for manufacturing a low dielectric constant copper-clad laminate using the low dielectric constant polyimide produced according to this method is also provided. Accordingly, since the printed circuit board can be made thinner while matching the impedances, the portable electronic device can be made thinner, and the line width of the printed circuit board can be widened, so that the defective rate of the PCB manufacturing company can be drastically reduced, It can contribute to cost reduction greatly.

The invention will be described in more detail in the following examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

[ Manufacturing example : Polyamic acid  Preparation of solution]

Production Example 1 : Containing fluorine resin Polyamic acid  Preparation of solution ( P1 )

1 L of a polyethylene bottle was filled with nitrogen and charged with 765 g of dimethylacetamide (DMAc), 160 g of polytetrafluoroethylene micropowder (PTFE micro powder, particle size: 0.1 to 2.0 μm) 8.0 g of a polymer (acid value 26 mg KOH / g, base 1200) and 765 g of a bead having a diameter of 2 mm were placed and dispersed while stirring in a high-speed ball milling machine.

A 500 mL round bottom flask was charged with 19.5 g of the PTFE-dispersed solution, 154 g of dimethylacetamide, 12.15 g of pyromellitic dianhydride, 2,2'-bis (trifluoromethyl) -4,4'-diaminobis 17.85 g of phenyl was added and reacted with stirring with a stirrer while flowing nitrogen at 50 캜 for 10 hours to obtain a polyamic acid solution (P1) having a viscosity of about 20,000 cps. (PTFE content in solid content: 10% by weight)

Production Example 2 : Containing fluorine resin Polyamic acid  Preparation of solution ( P2 )

A polyamic acid solution (P2) was prepared in the same manner as in Preparation Example 1, except that the content of PTFE in the solid content of the polyamic acid solution was 40% by weight.

Production Example 3 : Containing fluorine resin Polyamic acid  Preparation of solution ( P3 )

1 L of a polyethylene bottle was filled with nitrogen and charged with 765 g of N-methylpyrrolidone (NMP), 160 g of polytetrafluoroethylene micropowder (PTFE micro powder, particle size: 0.1 to 2.0 μm) , 8.0 g of a polyester polymer (acid value 26 mg KOH / g, base 1200) as a dispersant and 765 g of a bead having a diameter of 2 mm were placed and dispersed while stirring in a high-speed ball milling machine. (PTFE content in solid content: 5% by weight)

9.2 g of the above PTFE-dispersed solution, 163 g of N-methylpyrrolidone, 14.36 g of 3,4,3 ', 4'-biphenyltetracarboxylic dianhydride, 2,2'- And 15.63 g of bis (trifluoromethyl) -4,4'-diaminobiphenyl were charged and reacted with stirring with a stirrer while flowing nitrogen at 50 ° C. for 10 hours to obtain a polyamic acid solution having a viscosity of about 18,000 cps P3).

Production Example 4 : Containing fluorine resin Polyamic acid  Preparation of solution ( P4 )

A polyamic acid solution (P4) was prepared in the same manner as in Preparation Example 3 except that the content of PTFE in the solid content of the polyamic acid solution was 30% by weight.

Production Example 5 : Polyamic acid  Preparation of solution ( P5 )

170 g of dimethylacetamide, 12.15 g of pyromellitic dianhydride and 17.85 g of 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl were placed in a 500 mL round bottom flask, The mixture was allowed to react for 10 hours while stirring using a stirrer while flowing nitrogen to obtain a polyamic acid solution (P5) having a viscosity of about 16,000 cps. (0 wt% of PTFE in solid content)

Production Example 6 : Containing fluorine resin Polyamic acid  Preparation of solution ( P6 )

A polyamic acid solution (P6) was prepared in the same manner as in Preparation Example 1 except that the content of PTFE in the solid content of the polyamic acid solution was 50% by weight.

Production Example 7 : Containing fluorine resin Polyamic acid  Preparation of solution ( P7 )

A polyamic acid solution (P7) was prepared in the same manner as in Preparation Example 1 except that the content of PTFE in the solid content of the polyamic acid solution was 25% by weight.

Production Example 8 : Containing fluorine resin Polyamic acid  Preparation of solution ( P8 )

A polyamic acid solution (P8) was prepared in the same manner as in Preparation Example 3 except that the content of PTFE in the solid content of the polyamic acid solution was 21.7% by weight.

[ Example 1 to  3 and Comparative Example  1 to 3: soft metal For laminate  Preparation of polyimide resin film]

[ Example 1 ]

The polyamic acid solution (P1) prepared in Preparation Example 1 was coated on a matte surface of a copper foil (thickness: 12 占 퐉) so as to have a final thickness of 20 占 퐉 and dried at 80 占 폚 for 10 minutes. The polyamic acid solution (P2) prepared in Preparation Example 2 was coated thereon to a final thickness of 20 μm, and dried at 80 ° C. for 10 minutes. The dried product was heated from room temperature in a nitrogen oven and cured at 350 ° C for 30 minutes.

After the curing was completed, the copper foil was etched to produce a polyimide film having a thickness of 40 um.

[ Example 2 ]

The polyamic acid solution (P3) prepared in Preparation Example 3 was coated on a matte surface of a copper foil (thickness: 12 占 퐉) so as to have a final thickness of 5 占 퐉 and dried at 80 占 폚 for 10 minutes. The polyamic acid solution (P4) was coated to a final thickness of 20 mu m and dried at 80 DEG C for 10 minutes. The polyamic acid solution (P3) prepared in Preparation Example 3 was coated thereon to a final thickness of 5 μm, followed by drying at 80 ° C for 10 minutes. The dried product was heated from room temperature in a nitrogen oven and cured at 350 ° C for 30 minutes.

After the curing was completed, the copper foil was etched to produce a polyimide film having a thickness of 30 um.

[ Example 3 ]

The solution was coated on the matte side of the copper foil (thickness: 12 占 퐉) to a final thickness of 5 占 퐉, followed by drying at 80 占 폚 for 10 minutes. ≪ Preparation of coating solution: Polyamic acid solution (P5) prepared in Preparation Example 5 - Polyamic acid solution (P6) prepared in Preparation Example 6 - Polyamic acid solution (P5) prepared in Preparation Example 5 - One polyamic acid solution (P6).

The dried product was heated from room temperature in a nitrogen oven and cured at 350 ° C for 30 minutes. After the curing was completed, the copper foil was etched to prepare a polyimide film having a thickness of 20 um.

[ Comparative Example 1 ]

The polyamic acid solution (P7) prepared in Preparation Example 7 was coated on a matte surface of a copper foil (thickness: 12 mu m) so as to have a final thickness of 40 mu and dried at 80 DEG C for 10 minutes. Then, the temperature was elevated from room temperature in a nitrogen oven And curing was carried out at 350 DEG C for 30 minutes.

After the curing was completed, the copper foil was etched to produce a polyimide film having a thickness of 40 um.

[ Comparative Example 2 ]

The polyamic acid solution (P8) prepared in Preparation Example 8 was coated on a matte surface of a copper foil (thickness: 12 μm) so as to have a final thickness of 30 μm, dried at 80 ° C. for 10 minutes, and then heated in a nitrogen oven And curing was carried out at 350 DEG C for 30 minutes.

After the curing was completed, the copper foil was etched to produce a polyimide film having a thickness of 30 um.

[ Comparative Example 3 ]

The polyamic acid solution (P7) prepared in Preparation Example 7 was coated on a matte surface of a copper foil (thickness: 12 mu m) so as to have a final thickness of 20 mu and dried at 80 DEG C for 10 minutes. Then, the temperature was elevated from room temperature in a nitrogen oven And curing was carried out at 350 DEG C for 30 minutes.

After the curing was completed, the copper foil was etched to prepare a polyimide film having a thickness of 20 um.

[ Experimental Example ]

The dielectric constant, elongation, and coefficient of linear thermal expansion of the polyimide films obtained in the Examples and Comparative Examples were measured as follows, and the results are shown in Tables 1 and 2, respectively.

(1) Method for measuring dielectric constant

The polyimide films obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were allowed to stand at 25 ° C and 50% RH for 24 hours, and then they were separated by using an Agilent E5071B network analyzer and a QWED SPD (split-post dielectric resonator) And measured at 10 GHz.

(2) Elongation measurement method

The polyimide films obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were measured according to the criteria of IPC-TM-650, 2.4.19 using a universal test machine (UTM) apparatus.

 (3) Method of measuring coefficient of linear thermal expansion (CTE)

The coefficient of linear thermal expansion of the polyimide films obtained in Examples 1 to 3 and Comparative Examples 1 to 3 was measured using a Mettler TMA / SDTA 840 instrument under the measurement conditions of 100 ° C to 200 ° C based on the criteria of IPC TM-650 2.4.24.3 Respectively.

Measurement result of the embodiment Example 1 Example 2 Example 3 Thickness and fluorine resin content The first polyimide resin layer 20um (10% by weight) 5 um (5 wt%) 5 um (0 wt%) The second polyimide resin layer 20um (40% by weight) 20um (30% by weight) 5 um (50 wt%) The first polyimide resin layer - 5 um (5 wt%) 5 um (0 wt%) The second polyimide resin layer - - 5 um (50 wt%) Overall Thickness 40um 30um 20um The average content of fluorine-based resin in the entire film 25 wt% 21.7 wt% 25 wt% Measurement result Dielectric constant 2.6 2.8 2.6 Elongation 10% 16% 12% Coefficient of linear thermal expansion 6.5ppm / K 5.7ppm / K 6.3 ppm / K

Measurement results of the comparative example Comparative Example 1 Comparative Example 2 Comparative Example 3 thickness 40um 30um 20um Fluorine resin content 25 wt% 21.7 wt% 25 wt% Measurement result Dielectric constant 2.6 2.8 2.6 Elongation 5% 8% 5% Coefficient of linear thermal expansion 7.6 ppm / K 7.1ppm / K 7.5 ppm / K

A comparison between Example 1 and Comparative Example 1, Example 2 and Comparative Example 2, and Example 3 with Comparative Example 3 show that the dielectric constant is measured in the same manner because the total fluorinated resin content is the same in the same thickness range, 1 to 3 had significantly higher elongation and smaller coefficient of linear thermal expansion than those of Comparative Examples 1 to 3.

Thus, it can be seen that a flexible metal clad laminate having higher performance and reliability in the embodiment can be provided.

Claims (16)

A first polyimide resin layer containing 0 to 20% by weight of a fluorine resin; And
And a second polyimide resin layer containing 20% by weight to 70% by weight of a fluororesin,
Wherein the content ratio of the fluororesin contained in the second polyimide resin layer is higher than that of the fluororesin contained in the first polyimide resin layer by at least 10 wt%
The fluororesin is a particle having the longest diameter of 0.05 mu m to 20 mu m,
At least one layer of each of the first polyimide resin layer and the second polyimide resin layer,
Wherein the ratio of the total thickness of the second polyimide resin layer to the total thickness of the first polyimide resin layer is 0.1 to 5.0.
The method according to claim 1,
Wherein the difference in the content ratio of the fluororesin contained in each of the first polyimide resin layer and the second polyimide resin layer is 20 wt% to 60 wt%.
delete delete The method according to claim 1,
A fluorine-based resin having an average content of 10% by weight to 50% by weight in the general formula (1)
[Formula 1]
The sum of the fluoric resin average content = [(the content ratio of the fluororesin contained in the first polyimide resin layer * the thickness of the first polyimide resin layer) + (the total amount of the fluororesin contained in the second polyimide resin layer Content ratio * total thickness of the second polyimide resin layer)] / (total thickness of the first polyimide resin layer and the second polyimide resin layer)
The method according to claim 1,
Wherein the fluorine resin contained in each of the first polyimide resin layer and the second polyimide resin layer is selected from the group consisting of polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene (ETFE), tetrafluoroethylene-chlorotrifluoroethylene copolymer (TFE / CTFE), and ethylene-chlorotrifluoroethylene resin (ETFE), ethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene copolymer resin (ECTFE). ≪ / RTI >
The method according to claim 1,
Wherein the fluororesin has a maximum diameter of 0.05 to 20 占 퐉.
The method according to claim 1,
Wherein each of the first polyimide resin layer and the second polyimide resin layer has a thickness of 0.01 탆 to 100 탆.
The method according to claim 1,
Wherein each of the first polyimide resin layer and the second polyimide resin layer comprises a polyimide resin having a weight average molecular weight of 5,000 to 500,000.
The method according to claim 1,
Wherein the first polyimide resin layer and the second polyimide resin layer each comprise a polyimide resin containing a repeating unit represented by the following formula (1):
[Chemical Formula 1]

In the above formula (1), Y ₁ is a tetravalent aromatic organic functional group, and X is a divalent aromatic organic functional group.
11. The method of claim 10,
Wherein Y < ₁ > is a tetravalent group selected from the group consisting of the following chemical formulas (21) to (27)
[Chemical Formula 21]

[Chemical Formula 22]

In Formula 22, Y ₁ represents a single bond, -O-, -CO-, -S-, -SO ₂ -, -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, -CONH-, _{a, -O (CH 2) n2 O-} , or -OCO (CH _{2) n3} OCO-, and wherein n1, n2 and n3 is an integer from 1 to _{10, - -COO-, - (CH 2} ) n1
(23)

Y ₂ and Y ₃ may be the same or different and each represents a single bond, -O-, -CO-, -S-, -SO ₂ -, -C (CH ₃ ) ₂ -, -C _{(CF 3) 2 -, -CONH-} , -COO-, - (CH 2) n1 - _{a, -O (CH 2) n2 O-} , or -OCO (CH _{2) n3} OCO-, wherein n1, n2, and n3 is an integer of 1 to 10,
≪ EMI ID =

In the above formula (24), Y ₄ , Y ₅ And Y ₆ may be the same or different from each other, and respectively a single bond, -O-, -CO-, -S-, -SO 2 -, -C (CH 3) 2 -, -C (CF 3) 2 -, _{a, -O (CH 2) n2 O-} , or -OCO (CH _{2) n3} a OCO-, wherein n1, n2 and n3 is 1 to 10 - -CONH-, -COO-, - (CH 2) n1 Lt; / RTI &
(25)

(26)

(27)

In the above Formulas 21 to 27, '*' means a bonding point.
11. The method of claim 10,
Wherein X is a divalent functional group selected from the group consisting of the following chemical formulas (31) to (34):
(31)

Wherein R ₁ is selected from the group consisting of hydrogen, -CH ₃ , -CH ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ CH ₃ , -CF ₃ , -CF ₂ CF ₃ , -CF ₂ CF ₂ CF ₃ , CF ₂ CF ₂ CF ₂ CF ₃ ego,
(32)

Wherein L ₁ is a single bond, -O-, -CO-, -S-, -SO ₂ -, -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, -CONH-, _{-COO-, - (CH 2) n1} -, -O (CH 2) and _{n2 O-, -OCH 2 -C (CH} 3) 2 -CH 2 O- , or -OCO (CH _{2) n3} OCO-, wherein n1, n2 and n3 are each an integer of 1 to 10,
R ₁ and R _{2, which} may be the same or different, are each hydrogen, -CH ₃ , -CH ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ CH ₃ , -CF ₃ , -CF ₂ CF ₃ , -CF ₂ CF ₂ CF ₃ , or -CF ₂ CF ₂ CF ₂ CF ₃ ego,
(33)

L ₂ and L ₃ may be the same or different and each represents a single bond, -O-, -CO-, -S-, -SO ₂ -, -C (CH ₃ ) ₂ -, -C _{(CF 3) 2 -, -CONH-} , -COO-, - (CH 2) n1 -, -O (CH 2) n2 O-, -OCH 2 -C (CH 3) 2 -CH 2 O- or - a OCO (CH _{2) n3} OCO-, and wherein n1, n2 and n3 is an integer from 1 to 10,
R _{1 ,} R ₂ and R ₃ may be the same or different and are each hydrogen, -CH ₃ , -CH ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ CH ₃ , -CF ₃ , -CF ₂ CF ₃ , - CF ₂ CF ₂ CF ₃ , or -CF ₂ CF ₂ CF ₂ CF ₃ ego,
(34)

In the above formula (34), L ₄ , L ₅ And L ₆ may be the same or different from each other, and respectively a single bond, -O-, -CO-, -S-, -SO 2 -, -C (CH 3) 2 -, -C (CF 3) 2 -, _{-CONH-, -COO-, - (CH 2} ) n1 -, -O (CH 2) n2 O-, -OCH 2 -C (CH 3) 2 -CH 2 O- , or -OCO (CH _{2) n3} OCO -, n1, n2 and n3 are each an integer of 1 to 10,
R _{1 ,} R ₂ , R ₃ and R ₄ may be the same or different and are each hydrogen, -CH ₃ , -CH ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ CH ₃ , -CF ₃ , -CF ₂ CF ₃ , -CF ₂ CF ₂ CF ₃ , or -CF ₂ CF ₂ CF ₂ CF ₃ ego,
In the above Formulas 31 to 34, '*' means a bonding point.
The method according to claim 1,
And at least one metal thin film including at least one selected from the group consisting of copper, iron, nickel, titanium, aluminum, silver, gold, and two or more alloys thereof.
14. The method of claim 13,
And a ten-point average roughness (Rz) of the surface of the metal thin film is 0.5 占 퐉 to 2.5 占 퐉.
14. The method of claim 13,
Wherein the metal thin film has a thickness of 0.1 占 퐉 to 50 占 퐉.
14. The method of claim 13,
And two metal thin films facing each other,
Wherein the first polyimide resin layer and the second polyimide resin layer are positioned between two metal thin films facing each other.