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: Provided is a method of manufacturing a circuit board including preparing a board structural body (11) and covering a conductor circuit element (13) on an outermost layer of the board structural body (11) with a cover film (14), wherein a heat treatment is performed while having a release material (15) interposed between the cover film (14) and a heat-processing device. The release material (15) is a laminate at least including, sequentially from the cover film toward the heat-processing device, a low friction film (16) selected from an ultrahigh-molecular-weight polyethylene film and a polytetrafluoroethylene film, a first aluminum foil (17), a first high-density polyethylene film (18a), a second high-density polyethylene film (18b), and a second aluminum foil (19). The first high-density polyethylene film (18a) and the second high-density polyethylene film (18b) are positioned such that respective MD directions are perpendicular to each other.

Abstract: A method of making a multi-layer circuit board that has a first film and at least two more films, second and third films, each being made of a thermoplastic polymer capable of forming an optically anisotropic melt phase, the first film having a low melting point, the second and third films having respective melting points higher than the melting point of the first film and at least one of the second and the third films having a circuit pattern thereon, and the first to third films are thermo compressed together with the first film interposed between the second and third films. This method entails causing at least one of the circuit patterns on one of the second and third films to contact an opposing surface of the other of the second and third films through the first film during the thermo compression bonding of the first to third films.

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 making a multi-layer circuit board that has a first film and at least two more films, second and third films, each being made of a thermoplastic polymer capable of forming an optically anisotropic melt phase, the first film having a low melting point, the second and third films having respective melting points higher than the melting point of the first film and at lest one of the second and the third films having a circuit pattern thereon, and the first to third films are thermo compressed together with the first film interposed between the second and third films. This method entails causing at least one of the circuit patterns on one of the second and third films to contact an opposing surface of the other of the second and third films through the first film during the thermo compression bonding of the first to third films.

Abstract: The method of manufacturing a film of thermotropic liquid crystal polymer includes extruding a thermotropic liquid crystal polymer of a kind in which any one of activation energies Ea1 and Ea2 of a melt viscosity is within the range of 30 to 90 kcal/mol, with the ratio (Ea1/Ea2) of the activation energy Ea1 relative to the activation energy Ea2 being within the range of 1 to 1.7. The activation energies Ea1 and Ea2 are measured by means of a capillary rheometer, including a nozzle of 1 mm in inner diameter and 10 mm in length disposed at an angle of introduction of 90° and a barrel of 9.55 mm in inner diameter, at respective shear rates of 243 seconds?1 and 2432 seconds?1 under a temperature ranging from the temperature [(Tm?10)° C.], which is lower by 10° C. than the melting point [(Tm)° C.] of the thermotropic liquid crystal polymer, to the temperature [(Tm+20)° C.], which is higher by 20° C. than the melting point [(Tm)° C.] of the thermotropic liquid crystal polymer.

Abstract: An apparatus for making an inflation film formed by extruding a raw resin in a molten state through a circular die to form a tubular film, and expanding the tubular film by the pressure of a gaseous medium introduced into an inner space thereof, while the tubular film is being cooled. The apparatus includes a cooling ring, at least one air ring coaxial with the circular die, and an adjusting device for adjusting the temperature of a gaseous medium, blown from the air ring, to a range effective to retain the tubular film, then still in a molten phase, in a condition in which the tubular film is inflated. A method for making an inflation film is also disclosed.

Abstract: An inflation film is formed by extruding a raw resin in a molten state through a circular die to form a tubular film, expanding the tubular film by the pressure of a gaseous medium introduced into an inner space of the tubular film, while the tubular film is being cooled to be solidified by blowing a cooling gas to the outer surface of the tubular film, and drawing the film while being progressively flattened by guide members. During the manufacture, the temperature Tf (° C.) of the solidified tubular film at the time it contacts the guide member for the first time is so adjusted as not to be higher than Tr (5) [° C.]; wherein Tr (5) represents the temperature at which the thermal deformation ratio of the solidified tubular film becomes 5% when it is measured, being loaded with a stress of a value equal to the frictional force received from the guide members under the conditions of manufacture of the film.

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: The method of manufacturing a film of thermotropic liquid crystal polymer includes extruding a thermotropic liquid crystal polymer of a kind in which any one of activation energies Ea1 and Ea2 of a melt viscosity is within the range of 30 to 90 kcal/mol, with the ratio (Ea1/Ea2) of the activation energy Ea1 relative to the activation energy Ea2 being within the range of 1 to 1.7. The activation energies Ea1 and Ea2 are measured by means of a capillary rheometer, including a nozzle of 1 mm in inner diameter and 10 mm in length disposed at an angle of introduction of 90° and a barrel of 9.55 mm in inner diameter, at respective shear rates of 243 seconds−1 and 2432 seconds−1 under a temperature ranging from the temperature [(Tm−10)° C.], which is lower by 10° C. than the melting point [(Tm)° C.] of the thermotropic liquid crystal polymer, to the temperature [(Tm+20)° C.], which is higher by 20° C.

Abstract: An apparatus for making an inflation film formed by extruding a raw resin in a molten state through a circular die to form a tubular film, and expanding the tubular film by the pressure of a gaseous medium introduced into an inner space thereof, while the tubular film is being cooled. The apparatus includes a cooling ring, at least one air ring coaxial with the circular die, and an adjusting device for adjusting the temperature of a gaseous medium, blown from the air ring, to a range effective to retain the tubular film, then still in a molten phase, in a condition in which the tubular film is inflated. A method for making an inflation film is also disclosed.

Abstract: An inflation film is formed by extruding a raw resin in a molten state through a circular die to form a tubular film, expanding the tubular film by the pressure of a gaseous medium introduced into an inner space of the tubular film, while the tubular film is being cooled to be solidified by blowing a cooling gas to the outer surface of the tubular film, and drawing the film while being progressively flattened by guide members. During the manufacture, the temperature Tf (° C.) of the solidified tubular film at the time it contacts the guide member for the first time is so adjusted as not to be higher than Tr (5) [° C.]; wherein Tr (5) represents the temperature at which the thermal deformation ratio of the solidified tubular film becomes 5% when it is measured, being loaded with a stress of a value equal to the frictional force received from the guide members under the conditions of manufacture of the film.

Abstract: To provide a simplified method of making a multi-layer circuit board capable of observing a high density surface mounting of electronic parts, a method is provided for making a multi-layer circuit board including a first film (A) and at least two more films, second and third films (B and C), each being made of thermoplastic polymer capable of forming an optically anisotropic melt phase. The first film (A) has a low melting point (Tm1), and the second and third films (B and C) have respective melting points (Tm2B and Tm2C) higher than the melting point (Tm1) of the first film (A). And at least one of the second and the third films have a circuit pattern thereon. The first to third films (A to C) are thermo compressed together with the first film (A) interposed between the second and third films (B and C).