JP3933128B2 - Resin film with metal foil, resin sheet with metal foil, metal-clad laminate - Google Patents

Description

  The present invention relates to a resin film with metal foil, a resin sheet with metal foil, and a metal-clad laminate used as printed wiring materials.

  In general, printed wiring boards are made of copper cloth laminated on a prepreg prepared by impregnating a base material such as glass cloth with a thermosetting resin such as epoxy resin, and this is heated and pressurized to produce a copper-clad laminate. After processing through-holes and through-hole plating on this copper-clad laminate, the copper foil on the surface is etched to form a wiring pattern, and the patterned copper-clad laminate is then passed through a prepreg. It is manufactured by laminating with copper foil or another circuit board and heating and pressing to form a multilayer. As the copper foil used at this time, the surface on the side to be laminated is formed on a roughened surface, the anchor effect by the roughened surface is used to increase the adhesion of the circuit, and the reliability as a printed wiring board can be ensured. Has been made.

  Recently, with copper foil produced by applying an adhesive resin such as an epoxy resin to the roughened surface of the copper foil, and making the adhesive resin a semi-cured (B stage) insulating resin layer. A printed wiring board, particularly a multilayer printed wiring board, is manufactured by using a resin sheet and thermocompression bonding a resin sheet with a copper foil to a circuit board or the like on the insulating resin layer side.

  Here, recent various electronic components are highly integrated, and ICs and LSIs incorporating small and high-density circuits are used. Wiring patterns are also used on printed wiring boards on which these electronic components are mounted. There is a demand for higher density, and printed wiring boards with fine patterns with fine line widths and pitches between lines are required. For example, in the case of a printed wiring board used for a semiconductor package, a substrate having high-density ultrafine wiring with a line width and a line-to-line pitch of about 30 μm is also required. However, since the copper foils conventionally used as described above are thick, it is practical to form such a high-density wiring pattern with a fine line spacing and line width using the copper foil. Have difficulty.

  Therefore, as a copper foil capable of forming a high-density and fine wiring pattern, Patent Document 1 proposes the following ultrathin copper foil with an adhesive. That is, the ultrathin copper foil with an adhesive of Patent Document 1 is coated with a curable resin composition that is cured by heat or the like on a surface-treated ultrathin copper foil that is temporarily bonded to a carrier and has a thickness of 9 μm or less. It is made to be semi-cured into a state to function as an adhesive. Examples of the carrier include aluminum, copper, iron, and paper. And this copper foil is used in the form of forming the wiring pattern on the copper foil by exfoliating and removing the carrier after the thermocompression bonding of the adhesive side surface and the circuit board etc. It is what is done. In this case, since the copper foil is as thin as 9 μm or less, it is said that a fine wiring pattern can be formed.

  However, the ultrathin copper foil of Patent Document 1 has the following problems. For example, when the carrier is aluminum, it is necessary to use an alkali etchant such as sodium hydroxide when etching and peeling / removing the aluminum of the carrier after thermocompression bonding. This alkali etching requires a long time. Therefore, a significant increase in manufacturing cost is caused. If the carrier is copper, the carrier copper can be physically peeled after thermocompression bonding, but the copper is expensive and the ultra-thin copper foil is reliably left on the circuit board side. It is difficult to make it possible to peel only the carrier copper from the ultrathin copper foil in the state, and disposal of the carrier copper that has been peeled and removed also becomes a problem. Furthermore, when the carrier is iron, for example, the carrier iron may rust during storage, and when the carrier is paper, the paper is water permeable, so it is extremely important in the process before thermocompression bonding. When the thin copper foil is treated with various chemical solutions, there is a problem that the paper may be altered or the chemical solution may penetrate into the interface with the ultrathin copper foil and peel off.

On the other hand, a copper foil with a resin film using a resin film as a carrier instead of the metal or paper as described above has also been proposed (see Patent Document 2). By using a resin film as a carrier, the above-mentioned problem of Patent Document 1 can be solved. And the copper foil with a resin film of patent document 2 is formed by laminating the electroless copper plating layer and the electrolytic copper plating layer in this order on the surface of the resin film, and the electroless copper plating layer and the electrolytic copper plating. The copper foil which consists of a layer is formed in 1-7 micrometers ultra-thin.
Japanese Patent Laid-Open No. 10-146915 JP 2000-141542 A

  As described above, the copper foil with a resin film of Patent Document 2 is superior to the conventional one, but generally the adhesion between the resin film and the electroless plating layer is low. Therefore, the plating film may be peeled off from the resin film during the electroless plating process, or the electroless plating layer may be peeled off from the resin film during the electroplating process performed after the electroless plating. There was a problem that it was difficult to provide a copper foil composed of an electroless plating layer and an electrolytic plating layer on the surface of the resin film. Moreover, when processing a printed wiring board etc. using the copper foil with resin, the resin film peeled carelessly from copper foil, and there existed a problem in handling etc.

  The present invention has been made in view of the above points. A metal foil with a metal foil and a resin sheet with a metal foil can be laminated on the surface of a resin film with good adhesion, and are excellent in usability. The object is to provide, and it is an object to provide a metal-clad laminate using these resin films with metal foil and resin sheets with metal foil.

  The resin film with copper foil according to claim 1 of the present invention is formed by applying the electroless plating layer 2 and the electrolytic plating layer 3 to the surface of the resin film 1 subjected to processing for improving the adhesion with the electroless plating layer 2. The electroless plating layer 2 is formed to have a thickness of 1 μm or less and the surface of the electroplating layer 2 is formed on the roughened surface 4.

According to the present invention, since the surface of the resin film 1 is processed to improve the adhesion with the electroless plating layer 2, the plating film is peeled off from the resin film 1 during the electroless plating process, or electrolysis is performed. The electroless plating layer 2 is not peeled off from the resin film 1 during the plating process, and the metal foil 6 composed of the electroless plating layer 2 and the electrolytic plating layer 3 is laminated and formed on the surface of the resin film 1. In addition, the resin film 1 is not inadvertently peeled off from the metal foil 6 when used for processing a printed wiring board, and the handleability is improved.
The invention of claim 1 is characterized in that the processing for improving the adhesion to the electroless plating layer 2 is a roughening treatment for forming irregularities on the surface of the resin film 1.
According to the present invention, the adhesiveness between the resin film 1 and the electroless plating layer 2 can be easily increased only by roughening the surface of the resin film 1.
Further, the invention according to claim 1 is characterized in that the concave-convex portion 8 has a depth-returned shadow portion of 10% or less in area ratio.
According to the present invention, the resin film 1 can be prevented from remaining on the surface of the electroless plating layer 2 when the resin film 1 is peeled from the electroless plating layer 2 of the metal foil 6.

The invention of claim 2 is Oite to claim 1, the resin film 1 is characterized in that a heat-peelable film is peeled from the metal foil 6 by heating.

  According to the present invention, the resin film 1 can be peeled off by heating for processing into a copper-clad laminate or the like, and the work of peeling the resin film 1 from the metal foil 6 is facilitated.

The invention of claim 3 is characterized in that, in claim 1 or 2 , the thickness of the electrolytic plating layer 3 is 0.5 to 105 μm.

  By forming the thickness of the electrolytic plating layer 3 to 0.5 μm or more, pinholes can be prevented from being generated in the electrolytic plating layer 3, and by forming the thickness of the electrolytic copper plating layer 3 to 105 μm or less. Further, it is possible to prevent peeling from the resin film 1 when the electrolytic plating layer 3 is bent.

The resin sheet with metal foil according to claim 4 of the present invention is an insulating resin in a B-stage state on the roughened surface 4 of the electrolytic plating layer 3 of the resin film A with metal foil according to any one of claims 1 to 3. It is characterized in that the layer 5 is laminated.

The resin sheet with metal foil formed in this manner is heated and pressure-molded over the circuit board or the like on the side of the insulating resin layer 5 to form the metal foil 6 on the substrate or the like using the insulating resin layer 5 as an adhesive layer. The metal- clad laminate can be easily manufactured without the need to use a prepreg or the like for lamination bonding.

  According to the present invention, since the surface of the resin film 1 is processed to improve the adhesion with the electroless plating layer 2, the plating film is peeled off from the resin film 1 during the electroless plating process, The electroless plating layer 2 is not peeled off from the resin film 1 during the plating process, and the metal foil 6 composed of the electroless plating layer 2 and the electrolytic plating layer 3 is laminated and formed on the surface of the resin film 1. be able to. In addition, the resin film 1 is not inadvertently peeled off from the metal foil 6 when used for processing a printed wiring board, and the handleability is improved.

  Hereinafter, the best mode for carrying out the present invention will be described.

  FIG. 1 shows an example of a resin film A with a metal foil according to the present invention. By laminating an electroless plating layer 2 and an electrolytic plating layer 3 in this order on one surface of a resin film 1, an electroless plating layer 2 is formed. And a metal foil 6 made of the electrolytic plating layer 3 is provided on one surface of the resin film 1, and the surface of the electrolytic plating layer 3 is formed as the roughened surface 4.

  Here, as said resin film 1 used as the carrier of metal foil 6, the flexible plastic film which can be bend | folded and deform | transforms comparatively easily with a physical force can be used. Specifically, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyolefins such as polyethylene and polypropylene, polyphenylene sulfide, polyimide, polyethylene naphthalate, polystyrene including syndiotactic polystyrene, polycarbonate, polyvinyl alcohol, polyvinyl chloride, polyvinyl chloride Examples thereof include various celluloses such as vinylidene, polyurethane and poly (cellulose acetate), polyamides such as (meth) acrylic resins and various nylons, and sheets of fluororesin. Of these, polyester is preferable, and polyethylene terephthalate is particularly preferable. Although the thickness of the resin film 1 is not specifically limited, About 5-250 micrometers is preferable, More preferably, it is about 20-100 micrometers.

  The resin film 1 may be either a simple substance or a composite. Moreover, a heat peelable film can also be used as the resin film 1. This heat-peelable film is sticky on the surface of the base resin film at room temperature, and when heated, it is coated with a heat-peelable adhesive that removes the stickiness, and a separator is applied to the surface of the heat-peelable pressure-sensitive adhesive layer. It is coated. Then, the separator is peeled off and a metal foil 6 is laminated and provided on the heat-peelable pressure-sensitive adhesive layer as described later. By using such a heat-peelable resin film as the resin film 1, the resin film 1 is formed from the metal foil 6 when the resin film A with metal foil, which will be described later, is heated and pressed to be laminated with a circuit board or the like. The operation of heat peeling and peeling off the resin film 1 is facilitated.

  And this invention gives the process which raises the adhesiveness of the electroless-plating layer 2 with respect to the resin film 1 to the surface of the side which laminates the electroless-plating layer 2 of the resin film 1 at least. It is more preferable that the treatment for improving the adhesion is performed on both surfaces of the resin film 1.

In the invention according to claim 1, processing to increase the adhesion of the electroless plating layer 2 to the resin film 1 will row by the uneven surface of the surface of the tree fat film 1 is roughened. The roughening treatment can be performed by a conventional method, for example, a physical method such as a sand blasting method or a chemical erosion method, and the surface of the resin film 1 is filled with filler-containing paint or other paint. The surface can also be roughened by coating. By forming a rough surface by roughening in this way, the adhesion between the electroless plating layer 2 and the resin film 1 can be enhanced by the anchor effect by the uneven surface, and during the electroless plating process It is possible to prevent the plating film from being peeled off from the resin film 1 and to prevent the electroless plating layer 2 from being peeled off from the resin film 1 during the subsequent electrolytic plating process. A metal foil 6 composed of an electroless plating layer 2 and an electrolytic plating layer 3 can be laminated on the surface. Moreover, since the uneven surface is transferred to the surface of the metal foil 6 from which the resin film 1 has been peeled to become a rough surface, the adhesion between the metal foil 6 and the dry film in the circuit forming process is improved. In the processed product that performs circuit formation in FIG. 6, if the resin has an appropriate rough surface as described above, the resin film 1 is peeled off and the dry film is laminated immediately, so that the yield of circuit formation can be achieved without a cleaning / polishing process. It will be possible to prevent problems.

Thus, when forming the surface of the resin film 1 in an uneven surface and improving adhesiveness, the adhesiveness of the electroless plating layer 2 with respect to the resin film 1 is improved by the surface roughness and roughening shape of the uneven surface of the resin film 1. It is possible to control, and after the metal foil 6 is laminated and bonded to a circuit board or the like, the peel strength can be set such that the resin film 1 can be appropriately peeled from the metal foil 6. For this purpose, in the invention according to claim 1, the concave portion 8 of the concavo-convex surface of the surface of the resin film 1 is an area ratio of the shadow portion of the depth return of the concave portion 8 as viewed from the electroless plating layer 2 side. in it formed so as to be within 10%. As shown in FIGS. 6A and 6B, an undercut portion 9 is formed so that the depth of the recess 8 is wider than the width of the opening. If it is, it means the part of the undercut part 9, and the dent when the concave part 8 is cut in parallel with the surface of the resin film 1 at the deepest part of the undercut part 9 (range a in FIG. 6). The area (ab) of the difference between the area a in the portion 8 and the area b of the opening portion of the recessed portion 8 (the range of b in FIG. 6) from the area a is the area of the shadow portion. It is preferable that the [area (ab) / area a] is within 10%. Then, after the metal foil 6 is laminated and bonded to the circuit board or the like, when the resin film 1 is peeled off from the metal foil 6, the resin film 1 is not left on the metal foil 6 side. It is important to prevent copper residue, and if the shadow portion of the depth return of the recess 8 is larger than 10% in area ratio, a lot of the resin film 1 remains when the resin film 1 is peeled from the electroless plating layer 2, Even if the metal foil 6 is polished in the circuit forming process, the resin film 1 may remain.

  Moreover, the process which improves the adhesiveness of the electroless-plating layer 2 with respect to the resin film 1 can be performed also by processing the surface of the resin film 1 with a coupling agent, for example. That is, in order to perform electroless plating on the resin film 1, it is necessary to apply a catalyst that causes electroless plating to the surface of the resin film 1, but there is no catalyst adsorption ability such as a polyethylene terephthalate film or a polyimide film. In the case of the resin film 1, the catalyst is generally adsorbed by a chemical reaction after surface modification using a strong acid, strong alkali, strong reducing agent, or the like. On the other hand, the present inventors can immerse the coupling film in an aqueous solution of a coupling agent without washing the resin film 1, wash it with water, and immerse it in a catalyst solution. It was discovered that the ring agent adsorbs palladium tin colloid, which is a general electroless plating catalyst, and easily causes electroless plating.

Therefore, by treating the surface of the resin film 1 with a coupling agent, the electroless plating catalyst is firmly adsorbed on the surface of the resin film 1, and the electroless plating layer 2 and the resin film formed using this catalyst as a nucleus. 1 can be improved. When analysis is performed using an X-ray photoelectron analyzer, a coupling agent layer, for example, a Si layer in the case of a silane coupling agent, is detected between the resin film 1 treated with the coupling agent and the electroless plating layer 2. It is confirmed that the adhesion between the resin film 1 and the electroless plating layer 2 is enhanced by the coupling agent. A water-soluble silane coupling agent is effective as the coupling agent used in the present invention, and a water-soluble aminosilane coupling agent is particularly preferable. Examples of the water-soluble aminosilane coupling agent include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (amino) having a general formula represented by NH ₂ —R—Si (OR ′) _3. Illustrate ethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, etc. Can do. Among these, N-β (aminoethyl) γaminopropyltriethoxy (or methoxy) silane, which is stable from the hydrophilicity and hydrolyzability of the aqueous solution, is desirable. These silane coupling agents can usually be treated by making an aqueous solution having a concentration of 0.001 to 5% by mass and immersing the resin film 1 in the aqueous solution. Here, washing with water after the coupling agent treatment is an essential step. One of the reasons is to eliminate the unevenness of the treatment of the coupling agent. The main reason is that when the coupling agent is mixed into the palladium-tin colloidal solution of the electroless plating catalyst, the coupling agent reacts with the colloid. Since the palladium-tin colloid coagulates and precipitates and the catalyst adhesion action is lost, a water washing step is necessary to eliminate the introduction of the coupling agent.

Furthermore , the process for improving the adhesion of the electroless plating layer 2 to the resin film 1 can be performed by a process in which the electroless plating catalyst applied to the surface of the resin film 1 is firmly integrated with the surface of the resin film 1. That is, as a method of this treatment, a method of adhering an electroless plating catalyst to the surface of the resin film 1, a method of mixing an electroless plating catalyst in the resin of the resin film 1, a resin layer mixed with an electroless plating catalyst, or inorganic There is a method of forming a layer on the surface of the resin film 1 to form a coating film containing an electroless plating catalyst. For example, after applying a solution of fine particles of palladium, gold, silver, copper or the like on the surface of the resin film 1 as an electroless plating catalyst and drying it, the electroless plating catalyst is heated by heating it above the softening point of the resin film 1. By coating the resin film surface with a resin material or an inorganic material that can be adhered to the surface of the resin film 1 and these fine particles appear on the surface, the resin layer or inorganic mixed with the electroless plating catalyst A coating film by a layer can be formed.

  After applying the electroless plating catalyst to the surface of the resin film 1 as described above, washing with water, further activating the catalyst with an accelerator, further washing with water, and placing the resin film 1 in the electroless plating bath. The electroless plating layer 2 can be laminated by forming an electroless plating film on the surface of the resin film 1 by a general electroless plating wet process. The electroless plating layer 2 is a layer formed in order to impart electroconductivity to the surface of the resin film 1 so that electrolytic plating can be performed. In the present invention, the thickness is set to 1 μm or less. It is. This is because even if the thickness of the electroless plating layer 2 is thicker than 1 μm, it is not only wasteful in terms of imparting conductivity, but also causes an increase in manufacturing cost. The thickness of the electroless plating layer 2 is preferably as long as the conductivity for electrolytic plating is ensured, and the lower limit is not particularly set, but practically about 0.02 μm is the lower limit.

  After the electroless plating layer 2 is formed on the surface of the resin film 1 in this way, the resin film 1 is immersed in an electrolytic plating solution and energized to the electroless plating layer 2, thereby electrolyzing the surface of the electroless plating layer 2. By depositing a plating film and laminating the electrolytic plating layer 3, a metal foil 6 composed of the electroless plating layer 2 and the electrolytic plating layer 3 can be formed. The thickness of the electrolytic plating layer 3 is preferably set in the range of 0.5 to 105 μm. When the electroplating layer 3 is a thin electroplating film having a thickness of less than 0.5 μm, a large number of pinholes are generated in the electroplating layer 3, and inconveniences such as disconnection are liable to occur when forming a wiring pattern. . If the thickness of the electrolytic plating layer 3 exceeds 105 μm, the electrolytic plating layer 3 may be peeled off from the resin film 1 when bent.

  Here, in the present invention, the electrolytic plating layer 3 which is the main body of the metal foil 6 is formed of copper, but in addition to being formed as a single layer of copper as shown in FIG. A plurality of layers mainly composed of a copper layer may be used. When the electrolytic plating layer 3 is formed of a plurality of layers made of a copper layer and a metal layer other than copper as shown in FIG. 1B, the layer 3a on the side in contact with the electroless plating layer 2 is nickel having a thickness of 1 μm or less. It is preferable that the layer 3b is made of a metal other than copper, such as zinc, chromium or cobalt, and the layer 3b opposite to the electroless plating layer 2 is formed of copper.

  The metal of the electroless plating layer 2 is not particularly limited, and may be formed of a single layer of metal other than copper, a copper alloy, or copper as shown in FIG. 1 (a), or as shown in FIG. 1 (b). You may make it form from several layers. The metal particles deposited as the electroless plating layer 2 are involved in the adhesive force with the surface of the resin film 1, and further, a heating / pressing process when the metal foil 6 is laminated on a circuit board or the like, or from the metal foil 6 to the resin film In order to prevent oxidation of the electrolytic plating layer 3 mainly composed of copper after peeling 1, the electroless plating layer 2 may be formed of a metal other than copper or a copper alloy. As a metal other than copper forming the electroless plating layer 2, nickel, cobalt, zinc, zinc oxide and the like are preferable, and as the copper alloy, an alloy of these metals and copper is preferable. In particular, nickel or an alloy of copper and nickel is desirable because of its good adhesive force with the resin film 1. When the electroless plating layer 2 is formed from a plurality of layers, the layers 2a and 2b are each formed of a metal or copper alloy other than copper, and the layer 2a on the side in contact with the resin film 1 is formed of a metal or copper alloy other than copper. Alternatively, the layer 2b on the side in contact with the electrolytic plating layer 3 may be formed of copper. Thus, by forming the layer 2b on the side in contact with the electrolytic plating layer 3 from copper, the speed at which the electrolytic plating layer 3 is performed by copper electrolytic plating can be increased. FIG. 1C shows an embodiment in which the electroless plating layer 2 is formed from a plurality of layers and the electrolytic plating layer 3 is formed of a single layer of copper.

When you form an electrolytic plating layer 3 on the electroless plating layer 2 as described above, by selecting as appropriate the to the electrolytic plating conditions to form a surface of the electrolytic plating layer 3 on the roughened surface 4 be able to. Specifically, by changing the bath composition, bath temperature, current density, electrolysis time, etc. at the final stage when the electroplating layer 3 is formed, the surface of the already formed electroplating film is 0.2 to 0.2. Copper particles of about 2.0 μm can be deposited as protrusions, and the roughened surface 4 can be formed by unevenness due to the copper particles. When the surface of the electrolytic plating layer 3 is formed on the roughened surface 4 by such roughening treatment, when the metal foil 6 is laminated by thermocompression bonding via a prepreg or the like on a circuit board or the like, the bonding strength is increased by the anchor effect. It can be obtained high.

  As described above, a resin film A with a metal foil in which the metal foil 6 composed of the electroless plating layer 2 and the electrolytic plating layer 3 is laminated on the resin film 1 can be obtained. It is preferable to further form a nickel layer 11 and a zinc layer 12 in this order on the roughened surface 4. When the zinc layer 12 is thermocompression bonded to the metal foil 6 and the circuit board using an adhesive such as a prepreg, the adhesive deteriorates due to the reaction between the copper of the electrolytic plating layer 3 and the adhesive, or the electrolytic plating. The surface of the layer 3 is prevented from being oxidized and functions to increase the bonding strength with the circuit board and the like, and the copper protrusion on the roughened surface 4 of the electrolytic plating layer 3 is an adhesive. When it bites into the copper, the copper in the protrusion can be easily removed by etching due to the action of zinc existing at the interface between the copper protrusion and the adhesive. The nickel layer 11 functions to prevent the zinc of the zinc layer 12 from thermally diffusing to the copper electroplating layer 3 side during the thermocompression bonding, thereby effectively exerting the above functions of the zinc layer 12.

Here, since zinc easily diffuses into copper, if the thickness of the zinc layer 12 is too thin, the amount of zinc present on the surface of the copper electroplating layer 3 is extremely reduced as a result of diffusion. The meaning of forming the zinc layer 12 disappears. If the thickness of the zinc layer 12 is increased, this problem will not occur. However, on the other hand, the amount of zinc eluted during etching increases and a clearance is generated between the roughened surface 4 of the electrolytic plating layer 3 and the adhesive layer. Also in this case, the bonding strength is reduced. For this reason, the thickness of the zinc layer 12 is preferably set in a range of 0.15~0.5mg / dm ^2.

On the other hand, the thickness of the nickel layer 11 that functions as a zinc diffusion preventing layer has a correlation with the thickness of the zinc layer 12. For example, when the thickness of the nickel layer 11 is thin, the function as a zinc diffusion preventing layer is not sufficiently exhibited. Therefore, when increasing the bonding strength between the electrolytic plating layer 3 and the adhesive, A relatively large amount of the nickel layer 11 needs to be present under the zinc layer 12 in view of the amount of zinc diffusion. When the thickness of the nickel layer 11 is made thinner than 0.01 mg / dm ² , the function as a zinc diffusion preventing layer is hardly expressed, and when the thickness is 0.05 mg / dm ² or more, it is formed thereon. diffusion thickness of the zinc layer 12 of zinc even thickness before and after the upper limit in the range of 0.15~0.5mg / dm ² to can be effectively prevented. However, if the thickness of the nickel layer 11 is greater than 0.05 mg / dm ² , the function of the zinc diffusion preventing layer is improved, but on the other hand, the nickel layer 11 inhibits etching. For this reason, the thickness of the nickel layer 11 is preferably set in the range of 0.01 to 0.05 mg / dm ² .

  The nickel layer 11 and the zinc layer 12 can be formed by applying a known electrolytic plating method or electroless plating method. Moreover, said nickel layer 11 may be formed with pure nickel, and may be formed with phosphorus-containing nickel containing 6 mass% or less of phosphorus.

Further, if the chromate treatment is further performed on the surface of the metal foil 6, an antioxidant layer can be formed on the surface of the metal foil 6. The chromate treatment can be carried out by a known method, for example, the method disclosed in JP-A-60-86894, which is 0.01 to 0.2 mg / in terms of chromium. An excellent anticorrosive ability can be imparted to the metal foil 6 by adhering about dm ² of chromium oxide and its hydrate.

  Further, by performing a silane coupling treatment on the surface of the metal foil 6 thus chromated, a functional group having a strong affinity for the adhesive can be imparted to the surface of the metal foil 6. The joint strength with the circuit board and the like can be further improved, and the rust prevention and heat resistance of the metal foil 6 can be improved. Examples of the silane coupling agent used in this case include vinyltris (2-methoxyethoxy) silane, 3-glycidoxypropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 3- Examples thereof include aminopropyltriethoxysilane. Silane coupling treatment can be carried out by making these silane coupling agents into an aqueous solution having a concentration of 0.001 to 5% by mass, applying them to the surface of the metal foil 6 and then drying by heating. In addition, it can replace with a silane coupling agent, and the same effect can be acquired even if it carries out a coupling process using coupling agents, such as a titanium type and a zircon type.

  The resin film A with a metal foil of FIG. 1 and FIG. 2 produced as described above can be used for producing a copper-clad laminate C, and this copper-clad laminate C is used. A printed wiring board such as a multilayer printed wiring board can be manufactured. For example, by superimposing a resin film A with a metal foil on an adhesive material such as a prepreg on the side of the metal foil 6 on a substrate 14 such as a circuit board having a wiring pattern formed on the surface, and heating and pressing it, A copper-clad laminate C in which the metal foil 6 is laminated and bonded to the substrate 14 with the insulating adhesive layer 16 made of an adhesive material as shown in FIG. 3A can be produced. And after peeling the resin film 1 from the metal foil 6 and exposing the metal foil 6 as shown in FIG. 3B, after processing the via hole and plating in the via hole as necessary, The printed wiring board D can be manufactured by etching the metal foil 6 to form the wiring pattern 15 as shown in FIG. The metal foil 6 can be used in the configuration in which the electroless plating layer 2 and the electrolytic plating layer 3 are laminated, and the wiring pattern 15 can be formed. In addition, the electroless plating layer 2 is peeled off from the electrolytic plating layer 3 together with the resin film 1. Thus, the wiring pattern 15 can be formed using the electrolytic plating layer 3 as the metal foil 6. In FIG. 3 (and FIGS. 4 and 5 described later), the nickel layer 11 and the zinc layer 12 are not shown. Further, a single-sided copper-clad laminate can also be produced by stacking the resin film A with metal foil on one or more prepregs on the metal foil 6 side and heating and pressing it. .

  Here, in the resin film A with metal foil, since the metal foil 6 is formed by plating on the surface of the resin film 1, it can be formed extremely thin, and the fine wiring pattern 15 It can be formed. Even if the metal foil 6 is extremely thin, the metal foil 6 is reinforced with the flexible resin film 1, so that the metal foil 6 will not be wrinkled or broken during handling.

  Next, FIG. 4 shows an example of the resin sheet B with metal foil according to the present invention. The roughened surface 4 of the metal foil 6 of the resin sheet A with metal foil produced as described above is made of an adhesive resin. A resin sheet B with a metal foil is formed by covering and laminating the insulating resin layer 5 in a B-stage state by covering and bonding a thermosetting resin for adhesion. Here, the B-stage state means that the thermosetting resin is in a semi-cured state, and even if the surface is touched with a finger, there is no sticky feeling and the insulating resin layer 5 can be stored in an overlapping manner, and heat treatment is performed. This means a state in which a curing reaction occurs in the thermosetting resin.

  Although it does not specifically limit as thermosetting resin which forms said insulating resin layer 5, For example, an epoxy resin, a polyimide resin, a polyfunctional cyanate ester compound etc. can be mentioned as a suitable thing. . In particular, the following resin composition is preferable because it can simultaneously improve the heat resistance and flame retardancy of the resin sheet B with metal foil.

  It is a resin composition containing a polyfunctional cyanate ester compound and a brominated epoxy compound, and has a glass transition temperature of 180 ° C. or higher after thermocompression bonding to a circuit board substrate or the like. The reason why the glass transition temperature is preferably 180 ° C. or higher is that, for example, a large temperature increase occurred during passage of a reflow furnace in the process of manufacturing a printed wiring board with high density mounting using the resin sheet B with metal foil. This is because the resin composition is not thermally deteriorated by these temperature rises when the temperature rises greatly during actual use.

As the polyfunctional cyanate ester compound, those disclosed in JP-A-10-146915 can be used. In this case, when the content of the polyfunctional cyanate ester compound is less than 50% by mass, the heat resistance of the insulating resin layer 5 is lowered, and when the content is more than 70% by mass, the manufactured metal foil Since the adhesiveness when the resin sheet B with adhesive is thermocompression bonded to a circuit board or the like under standard hot pressure conditions of, for example, a temperature of 170 ° C. and a pressure of 4.9 MPa (50 kg / cm ² ) for 60 minutes, the resin composition The content of the polyfunctional cyanate ester compound in the product is preferably set to 50 to 70% by mass.

  The brominated epoxy compound is a component blended in order to make the insulating resin layer 5 flame-retardant and to increase its heat resistance. Examples of brominated epoxy compounds having such a function include “Epicoat 5050” (bromine content 47 to 51 mass%) manufactured by Yuka Shell Epoxy Co., Ltd. and “Araldite 8018” manufactured by Asahi Ciba Co., Ltd. And so on. The amount of the brominated epoxy compound is preferably set to 12 to 20% by mass in terms of bromine. When the blending amount is less than 12% by mass, the flame retardant standard UL-94V0 cannot be satisfied, and when it exceeds 20% by mass, the obtained resin sheet B with metal foil is heated to a circuit board or the like. The flexibility at the time of press-bonding deteriorates, and further, there is a possibility that powder blowing increases during cutting processing of a printed wiring board manufactured using the resin sheet B with metal foil.

  In the case of a resin composition in which the content of the polyfunctional cyanate ester compound and brominated epoxy resin is the above-described values, the insulating resin obtained is obtained by applying the above standard hot pressure conditions during thermocompression bonding. The glass transition temperature of the layer 5 shows a value of 180 ° C. or higher. In addition, when antimony oxide is blended with a brominated epoxy compound, the amount of brominated epoxy compound can be reduced. For example, when about 2 mass% of antimony oxide is blended, the amount of brominated epoxy compound is blended. Is about 10% by mass, the UL standard can be satisfied.

  When the insulating resin layer 5 is formed, the resin or resin composition described above is dissolved in a solvent such as methyl ethyl ketone (MEK) or toluene to form a resin solution, and this resin solution is used as the metal foil 6 of the resin film A with a metal foil. After the coating on the roughened surface 4 by a roll coater method or the like, it can be carried out by heating and drying to remove the solvent to obtain a B-stage state. For example, a hot air drying furnace can be used for drying, and the drying temperature is preferably 100 to 200 ° C, more preferably 130 to 170 ° C.

  The resin sheet B with metal foil produced as described above can be used for producing a copper-clad laminate C, and a multilayer printed wiring board or the like using the copper-clad laminate C can be used. A printed wiring board can be manufactured. That is, first, the insulating resin layer 5 is superposed on a substrate 14 such as a circuit board, and then the whole is heated and pressed to thermally cure the insulating resin layer 5, whereby a metal foil is formed on the insulating adhesive layer 16 by the insulating resin layer 5. A copper-clad laminate C in which 6 is laminated and bonded to the substrate 14 as shown in FIG. Then, the resin film 1 is peeled to expose the metal foil 6 as shown in FIG. 5B, and the metal foil 6 is etched to form a predetermined wiring pattern 15 as shown in FIG. 5C. Thus, a printed wiring board can be manufactured. The metal foil 6 can be used in the configuration in which the electroless plating layer 2 and the electroplating layer 3 are laminated, and the wiring pattern 15 can be formed. In addition, the electroless plating layer 2 is peeled from the electroplating layer 3 and electroplated. The wiring pattern 15 can be formed by using the layer 3 as the metal foil 6. Moreover, a single-sided copper-clad laminate can also be produced by heating and press-molding a single resin sheet B with metal foil.

Thus, since the resin sheet B with metal foil can be laminated and bonded to the substrate 14 with the insulating resin layer 5, a multilayer printed wiring board can be manufactured without the need to use a prepreg. And although the prepreg has a predetermined thickness so that consisted substrate such as glass cloth, insulating resin layer 5 can be formed thin thickness in a range to ensure the adhesion and interlayer insulation, the thickness of the first layer An extremely thin multilayer printed wiring board having a thickness of 100 μm or less can be produced. The thickness of the insulating resin layer 5 is preferably 20 to 80 μm. When the thickness of the insulating resin layer 5 is less than 20 μm, the adhesive force is lowered and it is difficult to ensure interlayer insulation. On the contrary, if the thickness of the insulating resin layer 5 exceeds 80 μm, it becomes difficult to produce a very thin multilayer printed wiring board, and the flexibility of the formed insulating resin layer 5 is reduced, and cracks are caused during handling. Is likely to occur.

  Next, the present invention will be specifically described with reference to examples.

Example 1
A 400 mm × 400 mm × 100 μm thick polyester (PET) film was used as the resin film 1.

  First, a water-soluble aminosilane coupling agent, N-β (aminoethyl) γaminopropyltrimethoxysilane (manufactured by Chisso Corporation, trade name “Silaace S320”) is prepared as a 0.5 mass% 25 ° C. aqueous solution. The resin film 1 was immersed in the coupling agent solution for 1 minute for coupling treatment.

Next, the resin film 1 was immersed in a primary washing tank, a secondary washing tank, and a tertiary washing tank for 30 seconds each with ion-exchanged water, washed with water, and then washed with palladium- Immerse in a colloidal tin type “AT-105 Activating Solution” for 5 minutes to give a catalyst, and after washing with water, use “Sulcup AL-106 Accelerator” manufactured by Uemura Kogyo Co., Ltd. at 25 ° C. A 3 minute accelerated treatment was applied. After washing with water, the resin is immersed in an electroless nickel plating solution “Nimden LPX” manufactured by Uemura Kogyo Co., Ltd. for 1 minute under conditions of 90 ° C., bath load 0.8 dm ² / L, and deposition rate 8 μm / hr. An electroless nickel plating film having a gloss thickness of 0.15 μm was uniformly deposited on both surfaces of the surface of the film 1 to form an electroless plating layer 2a of nickel.

Further, the resin film 1 was immersed in an electroless copper plating solution “Sulcup PEA” manufactured by Uemura Kogyo Co., Ltd. for 3 minutes under conditions of 36 ° C., a bath load of 0.4 dm ² / l, and a deposition rate of 2.0 μm / hr. Then, an electroless copper plating film having a gloss thickness of 0.2 μm is uniformly deposited on the surface to form a copper electroless plating layer 2 b, and a nickel layer 2 a and a copper layer are formed on the resin film 1. The electroless plating layer 2 formed in a two-layer structure from the layer 2b was laminated.

Next, one surface of the electroless plating layer 2 is sealed so that only one surface is immersed in the electrolytic copper plating solution, and the other electroless plating layer 2 is energized to perform electrolytic plating of copper under the following conditions. Then, a 6 μm thick copper electroplating layer 3 is laminated on the surface of the electroless nickel electroless plating layer 2, and a copper foil 6 comprising the electroless plating layer 2 and the electroplating layer 3 is formed on one surface of the resin film 1. did. Note that the current density was increased gradually to 50A / dm ^2.

Bath composition: metal copper 55 g / L, sulfuric acid 55 g / L, chloride ion 30 ppm (as NaCl), sodium 3-mercapto-1-propanesulfonate 1.5 ppm, hydroxyethyl cellulose 10 ppm, bath temperature: 58 ° C., counter electrode: included Phosphor copper plate, current density: 50 A / dm ² .

  When the surface roughness of the copper electroplating layer 3 obtained in this way was measured by the method specified in JIS B0601, the in-plane variation of the surface of the copper electroplating layer 3 was as small as ± 0.2 μm. This is because the layer 2a on the surface side of the electroless plating layer 2 is copper and has low electric resistance.

The surface of the copper electroplating layer 3 was further subjected to the following copper plating to form a roughened surface 4. First, an electrodeposition bath having a composition composed of metallic copper: 20 g / L and sulfuric acid: 100 g / L was constructed. This is designated as bath (1). Further, an electrodeposition bath composed of metallic copper: 60 g / L and sulfuric acid: 100 g / L was constructed. This is called bath (2). The copper electroplating layer 3 was subjected to a roughening treatment for 5 seconds using a bath (1) under conditions of a bath temperature of 25 ° C. and a current density of 30 A / dm ² , thereby depositing copper particles on the surface. . Next, using the bath (2), a plating process is performed for 10 seconds under the conditions of a bath temperature of 60 ° C. and a current density of 15 A / dm ² , thereby providing a dense copper capsule plating layer covering the copper particles. Chemical surface 4 was formed.

  Thus, the resin film A with a copper foil as shown in FIG. At this time, when the surface of the copper electroplating layer 3 was observed with a microscope, it was a roughened surface 4 in which fine-particle projections were formed on the entire surface. The maximum particle diameter of the protrusions was 1.9 μm, the minimum value was 0.3 μm, and the Rz value was 3.4 μm. Next, a nickel layer 11 and a galvanized layer 12 were formed on the roughened surface 4 as follows.

First, a nickel plating bath having a composition of nickel sulfate hexahydrate 240 g / L, nickel chloride hexahydrate 45 g / L, boric acid 30 g / L, sodium hypophosphite 5 g / L was constructed, and zinc sulfate heptahydrate A galvanizing bath having a composition of 24 g / L of salt and 85 g / L of sodium hydroxide was constructed. Then, on the roughened surface 4 of the resin film A with copper foil, a stainless steel plate is used as the counter electrode, and nickel plating is performed for 1 second under conditions of a nickel plating bath temperature of 50 ° C. and a current density of 0.5 A / dm ^2. Further, a phosphorous nickel-containing layer 11 having a thickness of about 0.02 mg / dm ² is formed on the roughened surface 4, and a stainless steel plate is used as the counter electrode, the bath temperature of the galvanizing bath is 25 ° C., and the current density is 0.4 A / dm. 2 seconds ² conditions, subjected to zinc plating, thickness to form a zinc layer 12 of about 0.20 mg / dm ^2, to obtain a copper foil resin film a as shown in FIG.

  Next, this resin film A with copper foil was washed with water, and then chromate treatment was performed by immersing in a sodium hydroxide aqueous solution (liquid temperature: 55 ° C.) of chromium trioxide 3 g / L, pH 11.5 for 6 seconds. did. Further, the resin film with copper foil A, vinyltris (2-methoxyethoxy) silane was immersed in an aqueous solution of 2 g / L for 5 seconds, and then taken out, dried with hot air at a temperature of 100 ° C., and treated with a silane coupling agent.

The resin film A with copper foil thus obtained was cut into a length of 300 mm × width of 300 mm, and the surface on the side of the zinc layer 12 was a glass fiber cloth base epoxy resin prepreg sheet (FR-4) having a thickness of 1 mm. Placed on top of each other, sandwiched between two smooth stainless steel plates, hot pressed under conditions of a temperature of 170 ° C., a pressure of 4.9 MPa (50 kg / cm ² ), and a time of 60 minutes, and a 1 mm thick single-sided copper-clad A laminate was prepared. The copper foil 6 of the copper-clad laminate was covered with the resin film 1, but the resin film 1 could be peeled off with a slight force. The surface of the electroless plating layer 2 that appears when the resin film 1 is peeled off is Rz = 0.1 μm and is a mirror surface. And when the dry film ("DuPont" SP-100 ": 25 micrometers in thickness) is laminated on the surface of this electroless-plating layer 2 exposed with a 100 degreeC heating roll, since it peels easily, an electroless-plating layer The surface of No. 2 was subjected to buffing polishing with a brushing buff with a wet abrasive to laminate the dry film with a surface roughness of Rz = 1.0 μm.

  With respect to the copper foil 6 on the surface of the single-sided copper-clad laminate produced as described above, etching characteristics, bonding strength with a prepreg material, and hydrochloric acid resistance were measured according to the following specifications.

  Etching characteristics: The above dry film having a thickness of 25 μm was laminated on a single-sided copper-clad laminate as described above, and 100 linear parallel patterns having a line width of 35 μm, a line pitch of 25 μm, and a length of 30 mm were drawn and developed. Next, an etching process was performed by spraying an etchant composed of ferric chloride 2.0 mol / L and hydrochloric acid 0.4 mol / L to form a wiring pattern. In addition, the etching time to a laminated board performed the preliminary test using the same laminated board, investigated the optimal time until a copper residue was not recognized by the base of a wiring pattern, and employ | adopted the time. When the obtained wiring pattern was observed with a microscope for the presence or absence of a short portion and a cut portion, none was present, and the etching characteristics were good.

  Bonding strength: A sample was cut out from a single-sided copper-clad laminate, plated with copper so that the total thickness of the plating layer was 18 μm, and the peeling strength of the sample was determined in accordance with the method specified in JISC6511. It was measured. In addition, the thing whose value is 7.8 N / cm (0.8 kg / cm) or more is determined as a non-defective product. As a result of the measurement, the peel strength was 14.7 N / cm (1.5 kg / cm), indicating good bonding strength.

  Hydrochloric acid resistance: A sample on which a wiring pattern having a line width of 1 mm was immersed in hydrochloric acid (temperature: 25 ° C.) having a concentration of 12% by mass for 30 minutes, then taken out, measured for the above peeling strength, and peeled off before and after immersion in hydrochloric acid The strength reduction rate (%) was calculated. The smaller this value, the better the hydrochloric acid resistance. As a result of the measurement, the rate of decrease in peel strength was 1.0%, indicating good hydrochloric acid resistance.

(Example 2)
As the resin film 1, a polyethylene naphthalate (PEN) film having a size of 400 mm × 400 mm × thickness 50 μm was used.

  Then, the surface of the resin film 1 is subjected to sandblasting using abrasive grain alumina # 800 with a dry sandblasting apparatus one side at a time, and the pressure and shot time are adjusted so that Ra = 0.15 μm to roughen both surfaces. Made it. This surface was observed with a 1000 × electron microscope, and the area ratio of the shaded portion of the undercut portion 9 hidden in the resin recess 8 was measured to be 5%.

Next, this resin film 1 was immersed in a palladium-tin colloid type “AT-105 activating solution” manufactured by Uemura Kogyo Co., Ltd. at 25 ° C. for 5 minutes to give a catalyst, washed with water, and then manufactured by Uemura Kogyo Co., Ltd. Using “Sulcup AL-106 Accelerator”, an acceleration treatment was performed at 25 ° C. for 3 minutes and washed with water. After performing the wet electroless plating pretreatment in this manner, copper sulfate 0.01 mol / L, nickel sulfate 0.05 mol / L, sodium hypophosphite 0.3 mol / L, sodium citrate 0.2 Using an electroless plating bath having a composition of mol / L, borax 0.05 mol / L, stabilizer 5 ppm, and pH 9.0, electroless plating was performed for 4 minutes under plating conditions of 60 ° C. and stirring. As a result, an electroless plating layer 2 made of a copper alloy of 42 mass% copper, 52 mass% nickel, and 6 mass % phosphorus was formed on the surface of the resin film 1 with a thickness of 0.4 μm. The appearance of the electroless plating layer 2 was uniform and non-uniform, and was matte.

  Thereafter, electrolytic copper plating is performed in the same manner as in Example 1, a 6 μm thick copper electroplating layer 3 is laminated on the surface of the copper alloy electroless plating layer 2, and the electroless plating layer 2 and the electroplating layer 3. A resin film A with a metal foil in which a metal foil made of 1 was formed on one side of the resin film 1 was produced. Here, the in-plane variation of the 6 μm thick copper electroplating layer 3 was ± 0.3 μm.

  Moreover, using this resin film A with a metal foil, a copper-clad laminate was produced in the same manner as in Example 1, and the electroless plating layer 2 of the metal foil 6 after the resin film 1 was peeled from the metal foil 6 was obtained. The surface had Rz = 1.5 μm, and the peel strength of the resin film 1 was 1.5 N / cm (0.15 kg / cm), and there was no problem in peelability. Moreover, even if the surface which peeled the resin film 1 of the metal foil 6 was observed with a 1000 times electron microscope, adhesion of resin was not seen. Further, even when a dry film was laminated on the surface of the metal foil 6 of this copper-clad laminate with a laminator and a pattern for etching characteristics was exposed and developed in the same manner as in Example 1, the laminate film did not peel off.

  In the same manner as in Example 1, etching characteristics, peel strength, and hydrochloric acid resistance were measured. As a result, the etching characteristics are good with no short part and no cut part, the peel strength is good at 14.7 N / cm (1.5 kg / cm), and the hydrochloric acid resistance has a decrease rate of the peel strength of 1.0. %.

(Example 3)
As the resin film 1, a kneaded matte PET film (Teijin DuPont product number “377”) of 400 mm × width 400 mm × thickness 100 μm was used. The surface of the resin film 1 was Ra = 0.30 μm. And when this surface was observed with the 1000 times electron microscope, the area ratio of the shadow part of the undercut part 9 hidden in the resin dent part 8 was measured, and it was 4%.

  Using this resin film 1, an electroless plating layer 2 formed in a two-layer structure from a nickel layer 2a and a copper layer 2b was laminated in the same manner as in Example 1, and the thickness was further increased in the same manner as in Example 1. A 85 μm copper electrolytic plating layer 3 was laminated to prepare a resin film A with a copper foil.

  Thereafter, in the same manner as in Example 1, formation of the zinc layer 12 and the nickel layer 11 and the treatment with the coupling agent were performed on the resin film A with copper foil, and a copper clad laminate was produced in the same manner as in Example 1. And the roughness of the surface of the copper foil 6 after peeling the resin film 1 is Rz = 2.2 μm, and the peeling strength of the resin film 1 is 2.5 N / cm (0.25 kg / cm). There was no problem. Further, even when the surface of the copper foil 6 was viewed with a 1000 × electron microscope, no adhesion of resin was observed.

  In the same manner as in Example 1, etching characteristics, peel strength, and hydrochloric acid resistance were measured. As a result, the etching characteristics are good with no short part and no cut part, the peel strength is good at 14.7 N / cm (1.5 kg / cm), and the hydrochloric acid resistance has a rate of decrease of the peel strength of 1.0. %.

Example 4
As the resin film 1, a 400 mm × 400 mm × 50 μm thick thermoplastic polyimide film (“Kapton KJ” manufactured by Toray DuPont, softening point is 210 ° C.) was used.

  Then, the surface of the resin film 1 is subjected to sandblasting using abrasive grain alumina # 800 with a dry sandblasting apparatus one side at a time, and the pressure and shot time are adjusted so that Ra = 0.15 μm to roughen both surfaces. Made it. The surface of the resin film 1 was spin-coated with a nanoparticle-containing solution containing nanoparticles of cupric oxide having an average particle diameter of 50 nm at a concentration of 2% by mass, heated in air at 120 ° C. for 10 minutes, and dried. Thereafter, baking was performed at 220 ° C. for 5 minutes. Furthermore, this resin film 1 was immersed in a 0.03 mol aqueous solution of dimethylamine borane at 60 ° C. for 5 minutes to reduce copper oxide, thereby obtaining a resin film 1 having copper particles attached to the surface. This surface was observed with a 1000 × electron microscope, and the area ratio of the shaded portion of the undercut portion 9 hidden in the resin recess 8 was measured to be 5%.

Next, after this resin film 1 was washed with water, using an electroless copper plating solution “Sulcup PEA” manufactured by Uemura Kogyo Co., Ltd., a temperature of 36 ° C., a bath load of 0.4 dm ² / L and a deposition rate of 2.0 μm / hr. By soaking for 3 minutes under the conditions, an electroless copper plating film having a gloss thickness of 0.1 μm is uniformly deposited on the surface of the resin film 1, and the electroless plating layer 2 is deposited on the surface of the resin film 1. Formed.

  Thereafter, electrolytic copper plating is performed in the same manner as in Example 1 to form a copper electroplating layer 3 with a thickness of 0.8 μm, and a metal comprising the copper electroless plating layer 2 and the copper electroplating layer 3. A resin film A with metal foil in which the foil 6 was laminated was obtained.

  And using this resin film A with a metal foil, it shape | molded similarly to Example 1 and obtained the copper clad laminated board. In this case, the peel strength of the resin film 1 was 2.5 N / cm (0.25 kg / cm), and there was no problem with the peelability. Moreover, when the copper foil surface was observed with a 1000 times electron microscope, adhesion of resin was not seen.

  Furthermore, the surface of the metal foil 6 after peeling the resin film 1 was Rz = 1.0 μm. Then, a dry film (“DuPont” “SP-100”, thickness 25 μm) is laminated on the surface of the metal foil 6 exposed by peeling the resin film 1 of the copper-clad laminate with a heating roll at 100 ° C. 100 linear parallel patterns having a width of 35 μm, a line pitch of 25 μm, and a length of 30 mm were developed with a reverse negative. Thereafter, the metal foil 6 was energized and immersed in the same electrolytic plating bath as in Example 1, and copper was applied with a thickness of 10 μm to form a circuit by a semi-additive method. Finally, the dry film was peeled off and soft etching was performed to obtain a wiring pattern. The wiring pattern was good with neither a short part nor a cut part.

(Example 5)
As the resin film 1, a fluororesin film having a size of 400 mm × 400 mm × thickness 100 μm (“Neofluon film” manufactured by Daikin Chemical) was used.

  And the Au-Ag particle paint (Sumitomo Metal Mining Co., Ltd. "Transparent conductive film paint CKR") which uses the nanosized Ag particle coated with Au as a conductive component is applied to the resin film 1 at 100 to 200 ° C. A metal fine particle film was formed on the surface of the resin film 1 by heat treatment.

Next, after washing with water, an electroless copper plating solution “Sulcup PEA” manufactured by Uemura Kogyo Co., Ltd. was used at a temperature of 36 ° C., a bath load of 0.4 dm ² / L, and a deposition rate of 2.0 μm / hr. The copper electroless plating layer 2 having a gloss thickness of 0.1 μm was uniformly formed on the surface of the resin film 1 by immersing 1 in a rocking motion for 3 minutes. Electroless plating of chromium was performed thereon to form a chromium layer having a thickness of 0.05 μm. Further, electrolytic copper plating was carried out in the same manner as in Example 1 to form a copper electrolytic plating layer 3 with a thickness of 35 μm, and a resin with metal foil in which a metal foil 6 composed of the electroless plating layer 2 and the electrolytic plating layer 3 was laminated. Film A was obtained. The film thickness variation of the metal foil 6 was 35 ± 0.2 μm.

  And using this resin film A with a metal foil, it shape | molded similarly to Example 1 and produced the copper clad laminated board. When the resin film 1 is peeled from the copper-clad laminate, the conductive coating applied by heating to the resin film 1 has good adhesion to the resin film 1, and the chromium between the electroless copper plating layer 2 and the electrolytic copper plating layer 3 is good. Peeling occurred in the layers, and the resin film 1 was peeled off together with the electroless plating layer 2 up to the chromium layer. The surface of the metal layer 6 from which the resin film 1 was peeled off was Rz = 0.2 and a mirror surface.

(Example 6)
As the resin film 1, a 400 mm × 400 mm × 50 μm thick heat peelable film (“Riva Alpha” manufactured by Nitto Denko Co., Ltd .: 150 ° C. peeled product, a type with a separator on one side) is removed and used. Each surface was sandblasted with abrasive alumina # 2000 using a dry sandblasting apparatus, and both surfaces were roughened by adjusting the pressure and shot time so that Ra = 0.05 μm.

  Then, electroless plating was performed in the same manner as in Example 2, and a copper alloy electroless plating layer 2 was laminated on the surface of the resin film 1 to a thickness of 0.4 μm. By laminating the electroplating layer 3, a resin film A with a metal foil in which the metal foil 6 composed of the electroless plating layer 2 and the electroplating layer 3 was laminated on one side of the resin film 1 was produced.

Using this resin film A with metal foil, as in Example 1, the whole was sandwiched between two smooth stainless steel plates, under conditions of a temperature of 170 ° C., a pressure of 4.9 MPa (50 kg / cm ² ), and a time of 60 minutes. A single-sided copper-clad laminate with a thickness of 1 mm was manufactured by hot pressing. In this case, the resin film 1 made of a heat-peelable film after the heat and pressure molding was peeled off from the metal foil 6, and a thin foil copper-clad laminate could be obtained simply by removing the resin film 1.

(Comparative Example 1)
As the resin film 1, a 400 mm × 400 mm × 50 μm thick polyester (PET) film was used. The resin film 1 was immersed in a palladium-tin colloidal type “AT-105 activating solution” manufactured by Uemura Kogyo Co., Ltd. at 25 ° C. for 5 minutes, and was then washed with water. . Further, using “Sulcup AL-106 Accelerator” manufactured by Uemura Kogyo Co., Ltd., an acceleration treatment was performed at 25 ° C. for 3 minutes. Next, after washing with water, the resin film 1 is swung on an electroless nickel plating solution “Nimden LPX” manufactured by Uemura Kogyo Co., Ltd. for 20 minutes under the conditions of 90 ° C., bath load 0.8 dm ² / L, and deposition rate 8 μm / hr. It was immersed and electroless nickel plating was performed.

  However, in this case, since the surface of the PET resin film 1 is not treated, the electroless plating film cannot be attached to the surface of the resin film 1, and an electroless nickel plating film can be formed. There wasn't.

The resin film with metal foil which concerns on this invention is shown, (a), (b), (c) is a schematic sectional drawing which shows each embodiment, respectively. It is a general | schematic expanded sectional view which shows other embodiment of the resin film with metal foil which concerns on this invention. (A) is a schematic sectional drawing which shows embodiment of the copper clad laminated board which concerns on this invention, (b), (c) is sectional drawing which shows the process of manufacturing a printed wiring board. The resin sheet with metal foil which concerns on this invention is shown, (a), (b), (c) is a schematic sectional drawing which shows each embodiment. (A) is a schematic sectional drawing which shows embodiment of the copper clad laminated board which concerns on this invention, (b), (c) is sectional drawing which shows the process of manufacturing a printed wiring board. It is for demonstrating the shadow part of the depth return of a dent part, (a) is an expanded sectional view, (b) is an enlarged plan view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin film 2 Electroless plating layer 3 Electrolytic plating layer 4 Roughening surface 5 Insulating resin layer 6 Metal foil

Claims (5)

  An electroless plating layer and an electrolytic plating layer are laminated in this order on the surface of a resin film that has been processed to improve adhesion with the electroless plating layer, and the electroless plating layer is formed to have a thickness of 1 μm or less and electrolytic plating. The surface of the layer is formed on a roughened surface, and the process for improving the adhesion with the electroless plating layer is a roughening treatment for forming unevenness on the surface of the resin film, and the concave portion of the unevenness is The resin film with a metal foil, wherein the shadow portion of the depth return is 10% or less by area ratio. The resin film with a metal foil according to claim 1, wherein the resin film is a heat-peelable film that is peeled off from the metal foil by heating . The resin film with metal foil according to claim 1 or 2, wherein the thickness of the electrolytic plating layer is 0.5 to 105 µm . Claim 1 of the metal foil resin film according to any of the 3, electrolytic plating layer of roughened surface on the B stage state of the insulating resin layer is laminated Rukin to the said formed isosamples genus foil resin Sheet . Metal foil resin film, or claim 4 metal-clad laminate characterized by comprising formed using a metal foil resin sheet according to according to any one of claims 1 to 3.

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