Abstract: To provide a thermoplastic liquid crystal polymer film capable of suppressing change in relative dielectric constant before and after heating, and a laminated and a circuit board using the same. In this film, a change ratio of a dielectric constant (?r2) of the film after heating to a dielectric constant (?r1) of the film before the heating satisfies the following formula (I) where the film is heated for 1 hour at a temperature in a range from a temperature being 30° C. lower than a melting point of the film to a temperature being 10° C. higher than the melting point, |?r2??r1|/?r1×100?5??(I) where ?r1 denotes the relative dielectric constant before the heating, ?r2 denotes the relative dielectric constant after the heating. These relative dielectric constants are measured at the same frequency in a range of 1 to 100 GHz.

Abstract: A power supply path structure is provided for a flexible circuit board and includes a first flexible circuit board that includes at least one first connection pad and a first opposite connection pad and a first power supply path connected between the first connection pad and the first opposite connection pad and a second flexible circuit board that includes at least one second connection pad and a second opposite connection pad and a second power supply path connected between the second connection pad and the second opposite connection pad, and the first flexible circuit board is stacked, in a vertical direction, on the second flexible circuit board in such a way that the first power supply path and the second power supply path form a parallel-connected power supply path that serves as a power path or a grounding path for the first flexible circuit board.

Abstract: Provided are a method for producing a thermoplastic liquid crystal polymer (TLCP) film having an improved thermo-adhesive property, a circuit board, and a method for producing the same. The production method of the TLCP film includes preparing a TLCP film as the adherend film and a TLCP film as the adhesive film; examining each of the prepared TLCP films for a relative intensity calculated as a ratio in percentage of a sum of peak areas of C—O bond peak and COO bond peak based on the total area of C1s peaks in the XPS spectral profile so as to calculate a relative intensity X (%) as for the prepared adherend film and a relative intensity Y (%) as for the prepared adhesive film; and controlling the TLCP film as the adhesive film to have a relative intensity Y by selection or activation treatment of the adhesive film so that the relative intensity X of the adherend film and the relative intensity Y of the controlled adhesive film satisfy the following formulae (1) and (2): 38<X+Y<65 ??(1) ?8.

Abstract: Provided are a thermoplastic liquid crystal polymer film having an improved thermo-adhesive property, a circuit board, and methods respectively for producing the same. The thermoplastic liquid crystal polymer film has a segment orientation ratio SOR of 0.8 to 1.4 and a moisture content of 300 ppm or less. The circuit board contains a plurality of circuit board materials wherein the circuit board materials are at least one member selected from the group consisting of an insulating substrate having a conductor layer on at least one surface, a bonding sheet, and a coverlay. At least one of the circuit board materials includes a thermoplastic liquid crystal polymer film. The circuit board shows a solder heat resistance when the circuit board is placed in a solder bath at 290° C. for 60 seconds in accordance with JIS C 5012.

Abstract: A metal-clad laminate excellent in isotropy, appearance, bondability between a TLC polymer film and a metallic sheet, and dimensional stability is provided less costly with a first step of thermally compressing the film with the metallic sheet by passing them through a nipping region between heating rolls, and a second step of heat-treating the resultant metal-clad laminate at a temperature not higher than the melting point of the film, wherein the film has thermal expansion coefficient ?L satisfying ?L=?T+? with thickness T, thickness coefficient ? and anisotropy coefficient ? of the film; wherein the coefficient ? is within the range of ?0.08 to ?0.01; the coefficient ? is within the range of ?M+6????M+10 with thermal expansion coefficient ?M of the metallic sheet; and thermal expansion coefficient ?T of the film is within ?M?2??T??M+3 with the coefficient ?M.

Abstract: Provided is a circuit board being composed of at least a thermoplastic liquid crystal polymer film and an adhesive layer containing a polyphenylene ether-based resin, the circuit board capable of being formed or shaped at a low temperature, and a method of manufacturing the same. The thermoplastic liquid crystal polymer film constitutes at least one circuit board material selected from the group consisting of an insulating substrate, a circuit layer material and a coverlay. The film is laminated to another circuit board material via the adhesive layer. The glass transition temperature of the adhesive layer is in a range from 200° C. to 300° C.

Abstract: A thermoplastic liquid polymer film and a method of producing the same are provided. The method includes preparing a thermoplastic liquid crystal polymer film that has dielectric constants of not larger than 3.25 both in an MD direction and in a TD direction; and performing drawing of the film while heating the film at a temperature in a range from a temperature (Td-60° C.) that is 60° C. lower than a heat deformation temperature (Td) of the film to a temperature (Td-5° C.) that is 5° C. lower than Td. The temperature of the heating during the drawing of the film may be in a range from a temperature (Td-40° C.) that is 40° C. lower than a heat deformation temperature (Td) of the film subjected to the drawing to a temperature (Td-10° C.) that is 10° C. lower than Td.

Abstract: To provide a thermoplastic liquid crystal polymer film capable of suppressing change in relative dielectric constant before and after heating, and a laminated and a circuit board using the same. In this film, a change ratio of a dielectric constant (?r2) of the film after heating to a dielectric constant (?r1) of the film before the heating satisfies the following formula (I) where the film is heated for 1 hour at a temperature in a range from a temperature being 30° C. lower than a melting point of the film to a temperature being 10° C. higher than the melting point, |?r2??r1|/?r1×100?5??(I) where ?r1 denotes the relative dielectric constant before the heating, ?r2 denotes the relative dielectric constant after the heating. These relative dielectric constants are measured at the same frequency in a range of 1 to 100 GHz.

Abstract: The object of the invention is to provide a wiring board having the uniform quality at a high yield which is produced by hot-pressing and laminating on a wiring board base material a thermotropic liquid crystal polymer which is excellent as a wiring board covering material. The present invention provides a method of making a wiring board comprising: hot-pressing and laminating a thermotropic liquid crystal polymer film on a wiring board base material on the surface of which at least one layer containing a electro-conductive circuit is exposed, characterized by that a viscoelastic characteristic of the thermotropic liquid crystal polymer film is measured at a low frequency within a laminating temperature region and the hot-pressing is carried out at a temperature selected so that the viscoelastic characteristic falls within a predetermined range.

Abstract: A metal-clad laminate excellent in isotropy, appearance, bondability between a TLC polymer film and a metallic sheet, and dimensional stability is provided less costly with a first step of thermally compressing the film with the metallic sheet by passing them through a nipping region between heating rolls, and a second step of heat-treating the resultant metal-clad laminate at a temperature not higher than the melting point of the film, wherein the film has thermal expansion coefficient ?L satisfying ?L=?T+? with thickness T, thickness coefficient ? and anisotropy coefficient ? of the film; wherein the coefficient ? is within the range of ?0.08 to ?0.01; the coefficient ? is within the range of ?M+6????M+10 with thermal expansion coefficient ?M of the metallic sheet; and thermal expansion coefficient ?T of the film is within ?M?2??T??M+3 with the coefficient ?M.

Abstract: A metal-clad laminate excellent in isotropy, appearance, bondability between a TLC polymer film and a metallic sheet, and dimensional stability is provided less costly with a first step of thermally compressing the film with the metallic sheet by passing them through a nipping region between heating rolls, and a second step of heat-treating the resultant metal-clad laminate at a temperature not higher than the melting point of the film, wherein the film has thermal expansion coefficient ?L satisfying ?L=?T+? with thickness T, thickness coefficient ? and anisotropy coefficient ? of the film; wherein the coefficient ? is within the range of ?0.08 to ?0.01; the coefficient ? is within the range of ?M+6????M+10 with thermal expansion coefficient ?M of the metallic sheet; and thermal expansion coefficient ?T of the film is within ?M?2??T??M+3 with the coefficient ?M.

Abstract: A method of making a thermotropic liquid crystal polymer film includes continuously heat treating of the thermotropic liquid crystal polymer film 2 while the latter is jointed to a sheet-like support member 4, and subsequently separating the heat-treated thermotropic liquid crystal polymer film 2 from the support member 4. The continuous heat treatment of the thermotropic liquid crystal polymer film 2 then jointed to the support member 4 is carried out for a predetermined heating time within the range of 5 to 60 seconds at a predetermined heating temperature T° C. equal to or higher than the melting point Tm° C. of the thermotropic liquid crystal polymer film less 15° C. (i.e., Tm?15° C.), but lower than the melting point Tm° C. (thus, Tm?15° C.?T° C.<Tm° C.), to thereby increase the thermal expansion coefficient of the thermotropic liquid crystal polymer film.

Abstract: To provide a release film which is used to avoid adherence between a press hot plate and a printed circuit board or a cover lay film at the time of press work effected to printed circuit boards such as printed wiring boards, flexible printed circuit boards and multilayered printed circuit boards and which has a heat resistance, a releasing property, a non-contamination property, a follow up capability relative to the circuit pattern, an excellent workability during processing and a small environmental impact at the time of disposal, the release film has a shear modulus of 5×105˜107 Pa at a hot press lamination temperature and is formed by overlapping at least one thermoplastic resin layer and at least one metallic layer one above the other.

Abstract: The object of the invention is to provide a wiring board having the uniform quality at a high yield which is produced by hot-pressing and laminating on a wiring board base material a thermotropic liquid crystal polymer which is excellent as a wiring board covering material. The present invention provides a method of making a wiring board comprising: hot-pressing and laminating a thermotropic liquid crystal polymer film on a wiring board base material on the surface of which at least one layer containing a electro-conductive circuit is exposed, characterized by that a viscoelastic characteristic of the thermotropic liquid crystal polymer film is measured at a low frequency within a laminating temperature region and the hot-pressing is carried out at a temperature selected so that the viscoelastic characteristic falls within a predetermined range.

Abstract: A metal-clad laminate excellent in isotropy, appearance, bondability between a TLC polymer film and a metallic sheet, and dimensional stability is provided less costly with a first step of thermally compressing the film with the metallic sheet by passing them through a nipping region between heating rolls, and a second step of heat-treating the resultant metal-clad laminate at a temperature not higher than the melting point of the film, wherein the film has thermal expansion coefficient ?L satisfying ?L=?T+? with thickness T, thickness coefficient ? and anisotropy coefficient ? of the film; wherein the coefficient ? is within the range of ?0.08 to ?0.01; the coefficient ? is within the range of ?M+6????M+10 with thermal expansion coefficient ?M of the metallic sheet; and thermal expansion coefficient ?T of the film is within ?M?2??T??M+3 with the coefficient ?M.

Abstract: To continuously produce a metal laminate having excellent dimensional stability and flatness, there is provided with a method of producing a metal laminate in which a thermoplastic liquid crystal polymer film (5?) capable of forming an optically anisotropic melt phase is heat-treated on a heat treatment roll having unevenness (91) on its surface and subsequently a metal sheet (3) is bonded to at least one side of the film (5?).

Abstract: A method of making a thermotropic liquid crystal polymer film includes continuously heat treating of the thermotropic liquid crystal polymer film 2 while the latter is jointed to a sheet-like support member 4, and subsequently separating the heat-treated thermotropic liquid crystal polymer film 2 from the support member 4. The continuous heat treatment of the thermotropic liquid crystal polymer film 2 then jointed to the support member 4 is carried out for a predetermined heating time within the range of 5 to 60 seconds at a predetermined heating temperature T° C. equal to or higher than the melting point Tm° C. of the thermotropic liquid crystal polymer film less 15° C. (i.e., Tm?15° C.), but lower than the melting point Tm° C. (thus, Tm?15° C.?T° C.<Tm° C.), to thereby increase the thermal expansion coefficient of the thermotropic liquid crystal polymer film.

Abstract: A method of producing a metal laminate for a circuit board includes a first step of press-bonding a thermotropic liquid crystal polymer film 1 having a segment orientation ratio SOR within a range not smaller than 0.90 and smaller than 1.15 along the longitudinal direction of the film, to a metal sheet 3 between hot rolls while the thermotropic liquid crystal polymer film 1 is in a tense or non-tense state; and a second step of heating the laminate obtained in the first step to a temperature not lower than the melting point of the thermotropic liquid crystal polymer film.

Abstract: To continuously produce a metal laminate having excellent dimensional stability and flatness, there is provided with a method of producing a metal laminate in which a thermoplastic liquid crystal polymer film (5′) capable of forming an optically anisotropic melt phase is heat-treated on a heat treatment roll having unevenness (91) on its surface and subsequently a metal sheet (3) is bonded to at least one side of the film (5′).

Abstract: A coating layer of a polymer capable of forming an optically anisotropic melt phase is formed by heat-pressing to a base material a film made of the polymer and having a segment orientation ratio of not greater than 1.3 and then separating the film into two halves so as to leave one of the halves on the base material, thereby obtaining a coated material made of the base material and the thin coating layer.