Abstract:
A molded article includes thermoplastic resin, and an organic material different from the thermoplastic resin inside said molded article, the organic material being located on and near a surface of said molded article.

Description:
[0001]     This application claims the right of priority under 35 U.S.C. §119 based on Japanese Patent Application No. 2003-389319, filed on Nov. 19, 2003, which is hereby incorporated by reference herein in its entirety as if fully set forth herein.  
       BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates generally to molded articles, methods for manufacturing the molding methods and apparatuses, and surface treatment methods, and more particularly to a molded article that is made of a thermoplastic resin (or molten resin) and has a modified surface, a molding method that utilizes a surface modification, a molding apparatus used for the molding method, and a surface treatment method of a molded article which utilizes the surface modification.  
         [0003]     A wide variety of plastic molded articles are made using injection molding, and the plasticized molten resin materials determine their physical properties. The plastic molded article may be subject to various types of printing, coating, formations of electric conductors and metal films, junctions with another molded article, and other posttreatments. These necessary posttreatments generally activate a surface of the plastic molded article for surface modification and processing improvement.  
         [0004]     On the other hand, the electroless plating is widely used to form a metal conductor film on a surface of an electronic apparatus made of the plastic molded article. The electronic plating procedure to plastic is generally pursuant to a flowchart shown in  FIG. 9  although it slightly differs according to materials and other conditions.  
         [0005]     The “degreasing” step initially removes the oil etc. from the surface of the molded article, and the “etching” step roughs the surface. The etching uses chrome acid solution and alkali metal hydroxide solution. The etchant requires a posttreatment, such as neutralization, causing increased cost, and the toxic etchant is problematic in handling. The “wetting” step then improves wettability using a process with surfactant solution, and the “catalyst (catalyzing)” step attaches catalyst to the plastic surface. For palladium catalyst, the “catalyzing” process impregnates the plastic into hydrochloric acid solution consisting of stannous chloride and palladium chloride. After the “catalyzing” step, the “accelerator (catalyst activation)” step activates plating catalyst using acid, such as sulfuric acid and hydrochloric acid. The “electroless plating” is not available until these processes finish.  
         [0006]     Some processes have conventionally been proposed which rough a surface without etching (see for example, Japanese Patent Applications, Publication Nos. 9-59778 and 2001-303255). These references propose to form a thin film including plating catalyst on a plastic surface using organic binder and UV cure resin. Similarly, as disclosed, for example, in Japanese Patent Application, Publication No. 6-87964, technology has already known which irradiates ultraviolet (“UV”) laser onto and modifies a plastic surface in an atmosphere of gas, such as amine compounds. Other known surface modification technologies include corona discharge treatments, plasma treatments and UV treatments.  
         [0007]     A semi-additive method has been known as one of methods that form wiring on a circuit board using electroless plating and electrolysis plating.  FIG. 10  shows this flow. This method uses the “electroless plating” step to form a plated layer with a thickness of 1 to 2 μm on the entire substrate using the same steps as discussed above. Then, the “exposure and development” step follows with masking after a “photosensitive film and resist” are formed, so as to form film and resist layers that include a wiring pattern. The “electrolysis plating” step forms an electrolysis plated layer on the electroless plated layer that has exposed. After the film and resist are removed, soft etching forms plated wires by removing the electroless plated layer from part other than the wiring part. Due to bad adhesion properties with resin, the copper plating would sometimes require a posttreatment referred to as “black treatment”, which creates fine projections made of copper (oxide) to enhance an anchor effect with the resin.  
         [0008]     Methods have been also conventionally proposed which provide a molded article with a three-dimensional circuit (see, for example, Japanese Patent Applications, Publication Nos. 4-76985 and 1-206692). These methods initially form a plastic three-dimensional circuit board by resin molding. Then, an electroless plated layer is entirely formed and the photoresist is entirely applied after the surface is made rough and catalyzed. The surface is exposed through a photomask, and developed to remove part other than circuit-pattern forming part. After the electrolysis plating and electroless plating using Ni and Au follow, photoresist is peeled off and unnecessary portion of the electroless plating is removed. It is difficult to form the photoresist as a uniform three-dimensional structure. Japanese Patent Application, Publication No. 4-76985 proposes to use electrodeposition resist, but this resist has disadvantageously low alkali resistance.  
         [0009]     A method for forming a three-dimensional circuit while maintaining a flat surface of an injection-molded article has also been proposed (see, for example, Matsushita Electric Technical Report August of 2002). This reference discloses surface modifications using vacuum plasma processing to a surface of an injection-molded article, a formation of a metal membrane using copper etc. with sputtering, and electronic plating after a pattern is formed by direct drawing using a laser. This process does not deteriorate surface roughness unlike the conventional etching, but has a disadvantage in a limited type of base plastic material so as to maintain the adhesion characteristic with the sputtered membrane.  
         [0010]     On the other hand, along with recent larger signal transmission amounts, circuit boards is very likely to handle high frequencies, and a delayed signal transmission speed becomes problematic. One important solution for this problem is a reduction of the dielectric constant and dissipation factor of a substrate. Accordingly, a method for reducing the lowered dielectric constant is proposed which produces a plastic base material with a high expansion ratio, for example, by using physical and chemical blowing agents, such as supercritical fluid and carbon oxide gas (see, for example, Japanese Patent Application, Publication No. 7-202439). However, the conventional approach of expanding the base material inevitably weakens the strength of the base material.  
         [0011]     No technologies have yet been proposed which may provide an efficient and easy surface modification to molded articles and have a wide variety of applications. In addition, the conventional plastic electroless plating processes are complex and expensive as well as being problematic in handling waste disposal of many hazardous materials. No processes are proposed which easily provide thermoplastic resin materials with an electric circuit in a wide variety of applications, or no molded articles and molding methods which restrain the lowered strength of the base material while blowing only primary coat part of the electric circuit pattern.  
       BRIEF SUMMARY OF THE INVENTION  
       [0012]     Accordingly, in order to solve the above disadvantages, it is an exemplified object of the present invention to provide a molded article that has an entirely or locally modified surface with an easy process but without roughing the surface or using a large amount of hazardous materials so that the surface is applicable, for example, to the electroless plating. It is also an exemplified object of the present invention to provide a molding method of the molded article, and a molding apparatus used to the molding method.  
         [0013]     A molded article according to one aspect of the present invention includes a convex part on a surface of the molded article, the molded article being made of thermoplastic resin, and an organic material, different from the thermoplastic resin inside the molded article, the organic material being located on and near a surface of the convex part. The term “near a surface of the molded article” means “in the molded article and close to the surface”, and properly defined by an object of surface modification and materials to be used, preferably within 100 μm from a surface, and more preferably within 10 μm from a surface. Since the organic material is included on or near the surface of the convex part, the surface of the molded article can be modified by the action of the organic material. The modified part may be an entire surface or part of the surface of the molded article.  
         [0014]     The convex part preferably has an elongated shape and having a sectional area between 0.005 mm 2  and 0.5 mm 2  on a plane orthogonal to a longitudinal direction of the convex part. When the sectional area of the convex part is smaller than 0.005 mm 2 , the thermoplastic resin material is insufficient and the supercritical fluid, which will be described later, cannot expand this part properly. On the other hand, when the sectional area of the convex part is greater than 0.5 mm 2 , the cellular porous media become too large to precisely form a wiring pattern on this convex part. When the convex part expands, the dielectric ratio reduces after the wiring pattern is formed on the convex surface. When the wiring patterns are isolated from each other on the surface of the convex part, an effect of the dielectric ratio reduction enhances.  
         [0015]     The organic material may include at least one of polyethylene glycol, dyestuff, fluoric low-molecular monomer, silicone oil, fluoric high-molecular monomer, and silicone polymer. Polyethylene glycol makes the organic material hydrophilic, and the dyestuff makes the organic material colorful. Fluoric low-molecular monomer and silicone oil make the organic material hydrophobic. The convex part may include metallic complex, and the metallic complex may be partially reduced to metal particles.  
         [0016]     Since the metallic particles reduced from the metallic complex infiltrate as catalyst cores in the molded article, the adhesion to a surface treating membrane (such as plated membrane) improves even when the convex part does not have a rough surface. Examples of the metallic complex include bis (cyclopentadienyl) nickel, bis (acetylacetnate) paradium (II), dimethyl platinum (cyclooctadiene) (II), hexafluoro acetylacetnate paradium (II), hexafluoro acetylacetnate hydrate copper (II), hexafluoro acetylacetnate platinum (II), hexafluoro acetylacetnate (trimethylphosphine), Ag (I), dimethyl (heptafluoro octanedionate) Ag (AgFOD), etc.  
         [0017]     A type of thermoplastic resin is arbitrary, and may include at least one of polycarbonate, polymethyl-methacrylate, cycloaliphatic olefin resin, poly(ether-imid), polymethyl pentene, amorphous polyolefin, polytetrafluoro-ethylene, liquid crystal polymer, styrene resin, polymethyl pentene, polyacetal, polyamid resin, polyimid, and polyamid-imid. Of course, the thermoplastic resin may use a combination of the above plural types, and polymer alloy that contains at least one of them as a main component, and add various types of fillers. The present invention is applicable to a film-shaped molded article having a thickness of 200 μm or smaller.  
         [0018]     A molding method according to another aspect of the present invention include the steps of accommodating in a mold, a molded article made of thermoplastic resin, clamping the mold with a first pressure so as to retain the molded article, and impregnating supercritical fluid that contains an organic material different from the supercritical fluid, into a surface of the molded article, and including the organic material into the surface of the molded article.  
         [0019]     According to this method, the supercritical fluid reduces the glass transition temperature on the surface of the molded article, and infiltrates in the swelled molded article. Since the supercritical fluid contains the organic material (functional organic material) and the organic material deeply infiltrates in the molded article, a highly durable surface modified membrane can be obtained unlike coating, etc. Since a simple method can modify a surface of the molded article made of thermoplastic resin (so-called plastic molded article, e.g., a film made of thermoplastic resin), which has been produced by injection molding, extrusion molding, casting, etc.  
         [0020]     The surface modification may use, for example, an aperture formed between the mold and the molded article to introduce the supercritical fluid through the aperture. In order to modify a specific portion of the molded article, a channel corresponding to the specific portion is formed in the mold so as to introduce the supercritical fluid through the channel. Since the glass transition temperature lowers and the molded article softens, the molded article can be made partially deformable or shaped, and the high size precision can be maintained similar to the injection molding.  
         [0021]     The impregnating step may circulate the supercritical fluid along the channel formed in the mold or impregnating step allows the supercritical fluid to reside in the channel. Thereby, the specific portion is locally surface-modified along the channel. A three-dimensional channel for the supercritical fluid along the surface of the molded article provides a local, three-dimensional surface modification to the molded article. The circulation or residence of the supercritical fluid can effectively promote the surface modification.  
         [0022]     The supercritical fluid may include at least one of air, CO, CO 2 , O 2 , N 2 , H 2 O, methane, ethane, propane, butane, pentane, hexane, methanol, ethyl alcohol, acetone, and diethyl ether. The supercritical fluid may be CO 2  and have a pressure between 10 MPa and 40 MPa, and a temperature between 40° C. and 150° C. CO 2  is preferable because it has solubility similar to that of n-hexane, serves as a plasticizer to certain thermoplastic resin materials, and is famous for high performance in injection molding and extrusion molding. Of course, the organic material may be any one of the above examples.  
         [0023]     In some instances, the supercritical fluid preferably uses supercritical N 2 . In order to impregnate metallic complex as the organic material into a surface of a molded article and to partially foam the surface, supercritical fluid is introduced as blowing gas that does not contain metallic complex into the surface of the molded article, after the supercritical fluid that contains metallic complex is circulated. In this case, when the blowing gas is supercritical CO 2 , supercritical CO 2  can extract the functional agent, such as metallic complex, that has once infiltrated into the surface of the molded article. Supercritical N 2  is less likely to act as a solvent, and has a reduced extracting force, solving this problem. One of various views for this reason says that supercritical N 2  can make a foam cell diameter smaller than supercritical CO 2 . The present invention can utilize this characteristic.  
         [0024]     The supercritical fluid may contain assistant, such as acetone, ethanol or other alcohols, for improving solubility of the organic material and for promoting the surface modification of the molded article. When the mold is clamped with a second pressure greater than the first pressure for press molding of the molded article, the press-molded article can be obtained with high size precision.  
         [0025]     The impregnating step may lower a glass transition temperature of the surface of the molded article, and the clamping step may form a convex part on the surface of the molded article. Since the supercritical fluid lowers the glass transition temperature of the surface of the molded article, the molded article can be deformed easily. Therefore, the convex part for a wiring pattern can be easily formed with high size precision.  
         [0026]     A molding method according to another aspect of the present invention includes the steps of accommodating in a mold a molded article made of thermoplastic resin, clamping the mold with a first pressure to retain the molded article, impregnating supercritical fluid locally into a surface of the molded article, and decompressing the molded article around the surface after the impregnating step, and expanding the surface of the molded article.  
         [0027]     The decompressing step is preferably conducted at a temperature below a glass transition temperature of the thermoplastic resin. The dielectric ratio reduces when the supercritical fluid locally infiltrates around the surface in the molded article and decompresses the molded article around the surface to expand the part. Therefore, this method is advantageous to a local formation of a wiring pattern at the specific portion of the molded article.  
         [0028]     A molding apparatus include a mold that accommodates a molded article made of thermoplastic resin, a pressing unit that opens and closes the mold, and a supercritical fluid generator that generates supercritical fluid, wherein the mold includes a channel for introducing the supercritical fluid into the mold.  
         [0029]     According to this method, the supercritical fluid reduces the glass transition temperature on the surface of the molded article, and infiltrates in the swelled molded article. Since the supercritical fluid contains the organic material the organic material deeply infiltrates in the molded article, a highly durable surface modified membrane can be obtained unlike coating, etc. Since a simple method can modify a surface of the molded article made of thermoplastic resin (so-called plastic molded article, e.g., a film made of thermoplastic resin), which has been produced by injection molding, extrusion molding, casting, etc.  
         [0030]     The surface modification may use, for example, an aperture formed between the mold and the molded article to introduce the supercritical fluid through the aperture. In order to modify a specific portion of the molded article, a channel corresponding to the specific portion is formed in the mold so as to introduce the supercritical fluid through the channel. Since the glass transition temperature lowers and the molded article softens, the molded article can be made partially deformable or shaped, and the high size precision can be maintained similar to the injection molding.  
         [0031]     A mold according to still another aspect of the present invention includes an accommodation part for accommodating a molded article, and an introducing part that includes a channel for impregnating supercritical fluid into a surface of the molded article, and for forming a convex part on the surface by pressing the molded article. Use of this mold for a molding apparatus provides similar effects to those of the above molding apparatus.  
         [0032]     A surface treatment method according to another aspect of the present invention includes the steps of impregnating supercritical fluid that contains metallic complex, into a surface of a molded article made of thermoplastic resin, partially reducing the metallic complex so as to allow metallic particles to separate out on the surface of the molded article, and processing the surface of the molded article by electroless plating, at which surface the metallic particles has separated out.  
         [0033]     According to this method, since the supercritical fluid reduces the glass transition temperature on the surface of the molded article and the supercritical fluid and metallic complex deeply infiltrate in the swelled molded article, a highly durable surface modified membrane can be obtained unlike coating, etc. In addition, since the metallic particles reduced from the metallic complex infiltrate as catalyst cores in the molded article, the adhesion to a surface treating membrane (such as electroless plated membrane) improves even when the convex part does not have a rough surface.  
         [0034]     Other objects and further features of the present invention will become readily apparent from the following description of preferred embodiments with reference to accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0035]      FIG. 1  is a block diagram of a schematic structure of a molding apparatus according to a first embodiment of the present invention.  
         [0036]      FIG. 2  is block diagram showing that a molded article is housed in a mold in the molding apparatus shown in  FIG. 1 .  
         [0037]      FIG. 3  is a partially enlarged sectional view of part A in  FIG. 2  and shows a clamping state with a first pressure.  
         [0038]      FIG. 4  is a partially enlarged sectional view of part A in  FIG. 2  and shows that the supercritical fluid infiltrates through the molded article.  
         [0039]      FIG. 5  is a partially enlarged sectional view of part A in  FIG. 2  and shows that the supercritical fluid containing metallic complex circulates.  
         [0040]      FIG. 6  is a partially enlarged sectional view of part A in  FIG. 2  and shows that the supercritical fluid infiltrates in the molded article.  
         [0041]      FIG. 7  is a partially enlarged sectional view of part A in  FIG. 2  and shows a clamping state with a second predetermined pressure.  
         [0042]      FIG. 8  is a sectional view showing a structure of a molded article obtained by a process according to the first embodiment of the present invention.  
         [0043]      FIG. 9  is a flowchart of a conventional electroless plating method.  
         [0044]      FIG. 10  is a flowchart for explaining a semi-additive method a conventional plating wiring method.  
         [0045]      FIG. 11  is a graph showing a curve fit of the Pd3d binding energy spectrum under the X-ray photoelectron spectroscopy. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     First Embodiment  
       [0046]     A description will be given of a molding apparatus and method according to a first embodiment of the present invention, with reference to FIGS.  1  to  8 .  FIG. 1  is a block diagram of a schematic structure of the molding apparatus  100  according to the first embodiment of the present invention. The molding apparatus  100  is a press molding apparatus used for press molding of a molded article. For example, a molded article which has been produced by injection molding or extrusion molding is accommodated and pressed in a mold in this press molding apparatus for partial or entire deformation or shaping.  
         [0047]     In these  FIGS. 17A  to  17 C denote decompression valves,  18 A to  18 F denote check valves, and  7 A to  7 E denote automatic air valves. While the first embodiment uses CO 2  for supercritical fluid, the usable type of supercritical fluid is not limited to this, and may be air, CO, CO 2 , O 2 , N 2 , H 2 O, methane, ethane, propane, butane, pentane, hexane, methanol, ethyl alcohol, acetone, and diethyl ether. While the supercritical condition of CO 2  requires the pressure of 7 MPa or greater and the temperature of 31° C. or greater, the preferable pressure is between 10 MPa and 40 MPa and the preferable temperature is between 40° C. and 150° C.  
         [0048]     A functional organic material is dissolved in CO 2  as supercritical fluid. While an arbitrary dissolution method is applicable, the dissolution method of the first embodiment includes the steps of transforming CO 2  supplied from a CO 2  tank  9  into a supercritical state in a supercritical fluid generator  8 ; maintaining the pressure in a reserve tank  12  at pressure P 0  using the decompression valve  17 C; and controlling the pressure in a dissolution sink  6  for dissolving the functional organic material in supercritical CO 2 , at pressure P 1  using the decompression valve  17 B. The pressure P 0  is 25 MPa, and the pressure P 1  is 20 MPa. The heater (not shown) controls the temperature from the pipe and tank from the reserve tank  12  to the filter  22  within a temperature range between 40° C. and 150° C. On the other hand, the temperature in the dissolution sink  6  is maintained at 50° C.  
         [0049]     The first embodiment uses bis (acetylacetnate) paradium (II) as the functional material in the dissolution sink  6 .  
         [0050]     Supercritical CO 2  in which metallic complex is dissolved and entrainer (or assistant) stored in an entrainer tank  14  are mixed and agitated in an agitator sink  16 . The entrainer uses, for example, acetone and ethanol and other alcohols. A feedback controller  13  controls an entrainer pump  15  and the automatic valve  7 A, and maintains the entrainer concentration constant in the agitator sink  16 .  
         [0051]     Supercritical CO 2 , in which metallic complex (Pd metallic complex) is dissolved as the functional organic material and the entrainer is mixed, is introduced into an upper mold  36  through an introduction pipe  28  by opening and closing actions of the automatic valve  7 B. Introduced supercritical CO 2  circulates in a channel, which will be described later, in the upper mold  36  and then exhausted through an exhaust pipe  25  by opening and closing actions of the automatic valve  7 E. Exhausted supercritical CO 2  is guided to a recovery sink  21 , and separated into respective components for recovery. A relief valve  20  automatically decompresses the recovery sink  21  to pressure P 3 , which is 1 MPa.  
         [0052]     Supercritical CO 2  (which does not contain the functional organic material or entrainer) that has been stored in the reserve tank  19  while the decompression valve  18 A maintains its pressure at pressure P 2 , is introduced to the upper mold  36  by opening and closing actions of the automatic valve  7 C. The pressure P 2  is 23 MPa. This structure enables the insides of the pipes  25  and  28  and the channel in the upper mold  36  to be cleansed to recover the functional organic material remaining in them. The decompression of the channel in the upper mold  36  can expand the surface of the molded article partially or entirely.  
         [0053]     This molding apparatus  100  includes a lower mold  24  integrated with a lower plate  11 , a hydraulic piston  10  installed in a hydraulic cylinder  23 , and the upper mold  3  integrated with the hydraulic piston  10 . The hydraulic cylinder  23  can apply the maximum pressure of 30 tons. While the first embodiment describes that the upper mold  36  forms the channel for introducing supercritical CO 2 , the channel may be formed in the lower mold  24  or in both the upper and lower molds  24  and  36 . A heater  26  and temperature control circuit  27  are respectively provided in the upper and lower molds  24  and  36  so as to provide two types of temperature controls. The heater  26  can heat up to 400° C. The temperature control circuit  27  can control the temperatures of the upper and lower molds  24  and  36  within a range between 30° C. and 145° C.  
         [0054]     A description will be given of pressing and a surface modification process to the molded article using this molding apparatus  100 . First, as shown in  FIG. 2 , a molded article  29  made of thermoplastic resin is accommodated between the upper and lower molds  36  and  24 . This molded article  29  is made of plastic having a three-dimensional shape, for example, by injection molding. The conceivable materials applicable to the thermoplastic resin are, for example, polycarbonate, polymethyl-methacrylate, cycloaliphatic olefin resin, poly(ether-imid), polymethyl pentene, amorphous polyolefin, polytetrafluoro-ethylene, liquid crystal polymer, styrene resin, polymethyl pentene, polyacetal, polyamid resin, polyimid, polyamid-imid, etc., but may include other materials. The molded article may have an arbitrary shape, such as a film-shaped molded article having a thickness of 200 μm or smaller. The first embodiment uses cycloaliphatic olefin resin (ZEON Corporation, Zeonex® 480R) having the glass transition temperature of about 150° C. for the thermoplastic resin. 4 pieces per row and 4 pieces per line, totally 16 pieces of products are connected via a runner  31  to form the molded article, where each piece has a size of 7 mm×7 mm×1.5 mm.  
         [0055]      FIG. 3  is an enlarged sectional view that partially enlarges part A in  FIG. 2 . In this figure, the molded article  29  is clamped at a first pressure of 10 tons between the upper and lower molds  24  and  36 . The first pressure is a relatively low pressure, and the upper and lower molds  24  and  36  retain the molded article  29  while pressure clearance  35  is remained. The temperatures of the upper and lower molds  24  and  36  are adjusted to 130° C. lower than the glass transition temperature of the molded article  29 .  
         [0056]     The upper mold  36  has a concave channel  32  for allowing supercritical CO 2  to circulate and reside. The channel  32  is used for a surface modification of the molded article  29  at a specific portion. The channel  32  forces the specific portion of the molded article  29  to follow its shape during deformation. In the first embodiment, a groove width  30 A is 0.3 mm, a groove depth  30 B is 0.1 mm, a groove width  30 C is 0.1 mm, and a groove depth  30 D is 0.1 mm. While these channels  32  have elongated shapes in a direction perpendicular to the paper surface of  FIG. 3 , their sectional areas are preferably set between 0.005 mm 2  and 0.5 mm 2  on a plane orthogonal to their longitudinal directions, or a plane parallel to the paper surface. In the first embodiment, these areas are 0.01 mm 2  and 0.03 mm 2 , respectively. The channels  32  can be formed in the lower mold  24  or both the upper and lower molds  24  and  36 . An arrangement of the channel  32  is determined in accordance with which portion should be surface-modified among the surfaces of the molded article  29 .  
         [0057]     These channels  32  are connected to each other via a connection groove  34  provided at the top of the upper mold  36  and a vent hole  33  that connects the connection groove  34  and the channel  32 , facilitating introductions and exhaustions of supercritical CO 2 .  
         [0058]     After pressing for 5 seconds, the automatic valve  7 C is released and supercritical CO 2  that does not contain metallic complex or entrainer is introduced in the channel  32 . The impregnation of supercritical CO 2  reduces the glass transition temperature of the surface portion of the molded article  29  corresponding to the channel  32  and deforms that portion (see  FIG. 4 ). Then, the automatic valve  7 B is released after the automatic valve  7 C is closed, and the automatic valve  7 E is released so as to introduce supercritical CO 2  in which metallic complex is dissolved, into the channel  32  from the agitator sink  16  and circulate it there (see  FIG. 5 ).  
         [0059]     After the circulation for 10 seconds, the automatic valve  7 E is closed and this supercritical CO 2  resides in the channel  32  for three minutes. This circulation and residence process repeats three times. Thereby, supercritical CO 2  and metallic complex impregnate in the surface of the molded article  29 . Then, the automatic valve  7 B is closed and the automatic valve  7 C is released. Supercritical CO 2  without metallic complex or entrainer is introduced into the channel  32  again. Thereby, the insides of the channel  32 , vent hole  33 , and connection groove  34 , etc. can be cleansed and the inner residual metallic complex can be removed.  
         [0060]     After the automatic valve  7 C is closed, the valve  7 F is opened and the channel is released to the air. As a consequence, metallic complex locally infiltrate in the specific portion on the surface of the molded article  29  (see  FIG. 6 ).  
         [0061]     Next, the heater heats the upper and lower molds  24  and  36  for 10 minutes up to 160° C., and the molded article  29  is pressed with a second pressure greater than the first pressure. As shown in  FIG. 7 , the pressure clearance  35  is eliminated, and the specific portion of the molded article  29  deforms along a shape of the channel  32 . Thereby, a convex portion  29   a  suitable for a wiring pattern can be precisely formed on the surface of the molded article  29 . This process can efficiently remove a ligand from metallic complex for catalyst activation. Then, the heater  26  is turned off, the upper and lower molds  24  and  36  are cooled down to 130° C., and the molded article  29  is taken out.  
         [0062]     This molded article  29  is put in a container that contains electroless copper plating solution, i.e., Okuno Chemical Industries Co., Ltd., OPC700A of 100 ml/l+Okuno Chemical Industries Co., Ltd., OPC700B of 100 ml/l, and agitated for 10 minutes at a temperature of 60° C. for copper plating processing. After it is cleansed with supersonic waves, pure water and methanol, the copper plated membrane is formed with a thickness of 10 μm on the convex portion  29   a  of the molded article  29  (see  FIG. 8 ).  
         [0063]     It is confirmed that the copper plated membrane  1  has a uniform thickness without swell, and exhibits practically satisfactory adhesive strength in a peel test. According to the resistance measurement that conducts the wiring pattern, it is confirmed that the low resistant wiring is formed without disconnection. It is also confirmed that it exhibited good insulation property between adjacent wires  
         [0064]     The runner  31  of molded article  29  is die-cut, and a molded article  4  has a sectional structure shown in  FIG. 8 . The convex portion  29   a  of this molded article  4  has two types, i.e., one having a width  5   a  of 0.1 mm and a height  5   b  of 0.1 mm, and the other having a width  5   c  of 0.3 mm and a height  5   d  of 0.1 mm. The segregations of metallic particles of metallic complex and Pd in either convex part  29   a  are confirmed by μESCA (Micro Electron Spectroscopy for Chemical Analysis: X-ray photoelectron Spectroscopy: XPS ESCA). The XPS provides types of elements from the binding energy of detected electrons and a ratio of these elements from the signal strength. A point analysis follows in the area of 0.05 μmΦ on the surface of the molded article having the critical dimension  5   a  of 0.1 mm in the first embodiment. The ESCA machine uses Quantum 2000 of ULVAC-PHI INC. An element ratio of metallic complex is similarly identified. Table 1 shows a result. 2.2 Atomic % of Pd element is detected from the surface of the molded article. A Focused Ion Beam (“FIB”) cuts part with 1 μm from the surface of the molded article. When the part is similarly analyzed, 1.8 Atomic % of Pd element is detected. Thereby, it is clear that the metallic component infiltrates into the uppermost surface down to a certain depth in the molded article of the instant embodiment.  
                                                                           TABLE 1                           CALCULATED RESULT OF       ELEMENTARY RATIO (UNIT: Atomic %)                C   N   O   Cl   Ni   Pd                        COMPLEX   69.5   —   24.0   —   —   6.4       MOLDED ARTICLE   56.9   1.5   29.5   3.6   6.3   2.2                  
 
         [0065]     The chemical bonding state on the upper surface of the molded article of the instant embodiment is analyzed using the XPS.  
         [0066]      FIG. 11  shows a curve fit of the Pd3d bonding energy spectrum. As shown in  FIG. 11 , the Pd3d spectrum is broad and separated into waveforms derived from PdO, PdO 2  and Pd complexes in addition to Pd metal. This means that the metallic complex that has infiltrated into the molded article is not completely reduced to metallic elements.  
         [0067]     The waveform separation is conducted as shown in  FIG. 11  in advance by analyzing the metallic complex powder and calculating a peak of each bonding energy. The Pd metallic component occupies 60% in the waveform separation. On the other hand, PdO complex occupies 20% and a combination of PdO 2  and Pd complexes occupies 20%.  
         [0068]     It is understood that 2.2×60%=1.32 (Atomic %) of Pd metallic component serves as a catalyst core in the electroless plating on the surface of the molded article of the instant embodiment which has a critical dimension  5   a  of 0.1 mm.  
       Second Embodiment  
       [0069]     Similar to the first embodiment, this embodiment allows supercritical CO 2  that contains metallic complex and entrainer to circulate and reside in the channel  32 . Then, in order to efficiently remove a ligand from metallic complex, the heater  26  heats the upper and lower molds  24  and  36  for 10 minutes up to 160° C. Next, the heater  26  is turned off, the upper and lower molds  24  and  36  are cooled down to 130° C., and then the channel  32  is decompressed. The pressure is released with the decompression of the channel  32 . Thereby, the atmosphere around the specific portion of the molded article  29  corresponding to the channel  32  is decompressed and the inside of that portion expands.  
         [0070]     It is known that foam cells becomes finer and increase as a pressure difference becomes large when the gas is generated from supercritical fluid or the decompression is conducted rapidly. The resin&#39;s temperature is preferably maintained low. Since the high temperature reduces the resin&#39;s viscosity, the air bubbles continue to grow, and are integrated with each other. Therefore, this decompression process is preferably conducted below the glass transition temperature (Tg) of the thermoplastic resin. In the present invention, Tg indicates physical properties of a bulk material that does not contain supercritical fluid.  
         [0071]     Thereafter, the molded article  29  is taken out and subject to the electroless plating. A good Cu wiring pattern can be obtained. An expansion is observed inside the convex portion  29   a  of the molded article  29  of the second embodiment. This expansion can reduce the dielectric ratio of the wiring pattern. An average foam cell diameter is about 50 μm at the obtained expansion part.  
       Third Embodiment  
       [0072]     Similar to the second embodiment, in order to efficiently remove a ligand from metallic complex after the channel  32  is released to the air, the heater  26  heats the upper and lower molds  24  and  36  for 10 minutes up to 160° C. Then, supercritical N 2  is introduced at 45° C. and 15 MPa from an inlet (not shown). The heater  26  is then turned off, the upper and lower molds  24  and  36  are cooled down to 130° C., and then the channel  32  is decompressed. The pressure is released with the decompression of the channel  32 . Thereby, the atmosphere around the specific portion of the molded article  29  corresponding to the channel  32  is decompressed and the inside of that portion expands.  
         [0073]     Thereafter, the molded article  29  is taken out and subject to the electroless plating. A good Cu wiring pattern can be obtained. An expansion is observed inside the convex portion  29   a  of the molded article  29  of the third embodiment. This expansion can reduce the dielectric ratio of the wiring pattern. An average foam cell diameter is about 30 μm at the obtained expansion part, which is finer than that obtained in the second embodiment.  
         [0074]     Further, the present invention is not limited to these preferred embodiments, and various variations and modifications may be made without departing from the scope of the present invention.  
         [0075]     Thus, the present invention uses the supercritical fluid to provide high-quality surface modification to the molded article. The present invention can also provide deformation and shape with high size precision in press molding. Since a simple process provides the surface modification without roughing the surface of the molded article, the present invention does not use a large amount of hazardous materials. The surface modification may be provided to the molded article entirely or locally.