JP4676376B2 - Circuit board manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a circuit board, and more particularly to a method for manufacturing a circuit board having a through hole.

  As electronic devices have become smaller and more multifunctional in recent years, circuit boards have also been increased in density and wiring patterns, and means for achieving such conditions include multilayer circuit boards. . As shown in FIG. 17, a circuit board formed by laminating a plurality of wiring layers is generally referred to as a through hole (through hole) 31, a via hole 32, and an interstitial via hole 33. The inner wall is covered with a conductive layer. Alternatively, conduction between layers is performed through pores such as through-holes filled with conductive layers and non-through-holes (hereinafter collectively referred to as “holes”).

FIG. 18 is a schematic view of the through hole as viewed from above. A conductive layer called a land 18 is formed around the through hole 17. There are various types of lands, such as a square, a circle, an ellipse, and an irregular shape, but a circular land is often used because of the occupied area or the ease of use of the design surface. Further, in order to cope with higher density, a through hole having a landless or narrow land width is required. Here, the land width (Lw) means the minimum value of the annular conductor width around the through hole in the case of a circular land. When the diameter of the through hole at the time of drilling is D ₀ and the diameter of the circular conductor of the circular land is D, the land width is zero in the land width Lw = (D−D ₀ ) / 2, and the narrow land The width means that the land width Lw = (D−D ₀ ) / 2 is larger than 0 and 40 μm or less.

  As a method for manufacturing a circuit board, a subtractive method, an additive method, and a semi-additive method are known. The additive method is a method in which a plating resist layer is provided on a non-circuit portion on the surface of an insulating substrate, and a conductive layer is formed on a portion corresponding to the circuit portion by an electroless plating process or the like. Although it is advantageous for microcircuit formation, since all the conductive layers are formed by electroless plating, there is a problem that the manufacturing cost is high. On the other hand, in the semi-additive method, a plating resist layer is provided on a non-circuit portion of an insulating substrate having a thin conductive layer on the surface, and a conductive layer is formed by electrolytic plating treatment on a portion corresponding to the circuit portion. In this method, after removing the resist layer, the thin conductive layer in the non-circuit portion is removed by flash etching to form a circuit. Since electrolytic plating capable of high-speed operation can be used, the manufacturing cost is lower than that of the additive method, but it is difficult to form all wiring pattern thicknesses uniformly by electrolytic plating. There is a problem that it is difficult. The subtractive method is a method of forming a circuit by providing an etching resist layer on a circuit portion of an insulating substrate having a conductive layer provided on the surface and etching away the exposed conductive layer of the non-circuit portion. Although there is a limit in terms of microcircuit formation compared to the other two methods, it is possible to produce a circuit board with simple processing, high productivity, the lowest manufacturing cost, and the most widely used. .

  The etching resist layer and the plating resist layer are formed by a screen printing method, a photofabrication method having an exposure development process using a photosensitive material, an ink jet method, or the like. When manufacturing a landless or narrow land width hole, it is important to align the holes in the hole drilling process, screen printing method, exposure process, ink jet method, etc. In the case of a hole having a narrow width or a narrow land, extremely high alignment accuracy is required. The land is most preferably shaped with a uniform width in all directions of the hole, that is, the hole and the land are concentric circles, but if the alignment is incorrect, there is a problem that the hole and the land are not concentric. there were.

  When manufacturing a circuit board by the subtractive method, it is necessary to protect the conductive layer previously provided on the inner wall of the hole with an etching resist layer and to protect the conductive layer on the inner wall of the hole with the etching resist layer so as not to be removed in the etching process. . In the case of forming an etching resist layer using a negative (photocrosslinking type) dry film photoresist, a tenting method in which the hole is covered with a dry film photoresist that is crosslinked by exposing the hole and the land portion, The conductive layer on the inner wall of the hole is protected by preventing the etchant from entering the hole.

  When protecting holes by the tenting method, it is important to drill holes and align the exposure process, especially in the landless and narrow land width holes required for high-density circuit boards. Alignment accuracy is required. That is, as shown in FIG. 19B, in the case of a large land width, a resist lid can be completely formed on the hole even if a positional deviation occurs by a distance X. As shown in the figure, in the case of a narrow land width, if the hole and the land are shifted by the same distance X, the land is detached from the hole portion, and the etching solution enters the hole, resulting in a problem of poor conduction. However, due to the accuracy of drilling, expansion / contraction of the substrate, dimensional change of the photomask for exposure, etc., the actual situation is that the alignment accuracy is limited. In addition, since there are many types of holes formed on the high-density circuit board and the number of holes is extremely large, it is very difficult to accurately align all the holes. Therefore, despite the need for landless and narrow land-width holes in high-density circuit boards, there is a problem that the land width must be designed large in order to perform tenting reliably. ing.

  Also, regarding the thickness of the dry film photoresist, in order to perform tenting more reliably, it is necessary to increase the thickness of the photoresist in order to form a stronger tent. When the wiring pattern is formed by etching, if the thickness of the etching resist layer formed by the dry film photoresist is thick, there is a problem that the liquid circulation property of the etching solution is deteriorated at the time of etching and the fine pattern cannot be formed. .

As a solution to these problems, the problem of misalignment between the land and the hole that occurred due to alignment was solved, and the landless and narrow land width holes required for increasing the density of the circuit board were solved. Has been proposed (Patent Document 1). This makes it possible to manufacture a circuit board having a landless or narrow land width by accurately opening a resist in a hole portion using a wet toner or the like. However, for toner electrodeposition using wet toner, it cannot be produced only by an existing production apparatus, and it is necessary to newly introduce a developing apparatus for toner electrodeposition. Therefore, implementation is difficult when there is no funds or installation space for introducing new equipment. Even if it can be introduced, management for performing toner electrodeposition stably is necessary, and there is a risk of circuit short circuit or circuit disconnection due to abnormal adhesion or insufficient adhesion of toner.
JP 2005-286295 A

  The object of the present invention is to solve the problem of misalignment between lands and holes that has occurred due to alignment, and to cope with landless and narrow land width holes that are required to increase the density of circuit boards. A method for manufacturing a circuit board is provided. In particular, a series of processes combining the ink filling process, the conductive ink filling process, the electrodeposition process, the metal plating process, the resist formation process, and the etching process as appropriate, without the need to introduce new equipment such as toner electrodeposition. Another object of the present invention is to provide a circuit board manufacturing method that can produce a circuit board having a landless or narrow land width hole and that is particularly applicable to a subtractive method.

The present inventors have conducted research to solve this problem,
(1) (a) preparing an insulating substrate having a conductive layer on the first surface of the insulating substrate having a through hole, the second surface opposite to the first surface, and the inner wall of the through hole;
(B) forming a first resin layer and a mask layer on the first surface and covering the conductive layer and the through hole opening on the first surface with the first resin layer and the mask layer;
(C) The first resin layer removing liquid is supplied from the second surface to remove the first resin layer on the through hole on the first surface and the periphery of the through hole, and the conductive layer on the periphery of the through hole on the first surface. Exposing the process,
(D) a step of applying resistance treatment to the second resin layer removal liquid on the first resin layer on the first surface;
(E) removing the mask layer on the first surface;
(F) forming a second resin layer and a mask layer on the second surface and covering the conductive layer and the through hole opening on the second surface with the second resin layer and the mask layer;
(G) The second resin layer removing liquid is supplied from the first surface to remove the second resin layer on the through hole on the second surface and the periphery of the through hole, and the conductive layer on the periphery of the through hole on the second surface. Exposing the process,
(H) removing the mask layer on the second surface;
Circuit board manufacturing method including
(2) Subsequent to the steps (a) to (h) described in (1),
(I) forming an etching resist layer on the exposed conductive layer;
(J) a step of removing the first resin layer and the second resin layer;
(K) forming a photocrosslinkable resin layer on the first surface and the second surface;
(L) A step of subjecting the photocrosslinkable resin layers on the first surface and the second surface to pattern exposure and photocrosslinking and curing in a pattern,
(M) removing the uncured photocrosslinkable resin layer on the first surface and the second surface and exposing the conductive layer in a pattern;
(N) A step of removing the exposed conductive layers on the first surface and the second surface by etching with an etchant;
(O) a step of removing the etching resist layer and the photocrosslinkable resin layer that has been photocrosslinked and cured;
Circuit board manufacturing method including
(3) The method for producing a circuit board according to (1) or (2), wherein the first resin layer and the second resin layer are photocrosslinkable resins, and the tolerization treatment is an exposure treatment,
(4) The method for producing a circuit board according to (2) or (3), wherein the etching resist layer is a metal layer insoluble in an etching solution for the conductive layer and is formed by pattern plating.
(5) The method for manufacturing a circuit board according to any one of (1) to (4), wherein the step (e) is performed before the step (d),
(6) The method for manufacturing a circuit board according to any one of (1) to (4), wherein the step (e) is performed after the step (f).
I found.

  In the method (1) for producing a circuit board according to the present invention, an insulating substrate having a conductive layer on the first surface of the insulating substrate having a through hole, the second surface opposite to the first surface, and the inner wall of the through hole. prepare. Subsequently, a first resin layer and a mask layer are formed on the first surface, and the conductive layer and the through hole opening on the first surface are covered with the first resin layer and the mask layer. Next, the first resin layer removing liquid is supplied from the second surface to remove the first resin layer on the through hole on the first surface and the periphery of the through hole, and the conductive layer on the periphery of the through hole on the first surface. To expose.

  Thereby, alignment is unnecessary and the conductive layer in the through hole and the peripheral part of the through hole can be exposed with high accuracy. Also, by controlling the removal conditions with the first resin layer removal liquid, it is possible to control the removal status of the first resin layer on the through hole and in the periphery of the through hole, and the exposure of the conductive layer in the periphery of the through hole The width can be controlled to a desired value.

  Thereafter, the first resin layer on the first surface is subjected to a resistance treatment for the second resin layer removing liquid. Thereby, the 1st resin layer of the 1st surface is not influenced with respect to the 2nd resin layer removal liquid processed later, and the already formed favorable opening situation can be maintained. Thereafter, the mask layer on the first surface is removed, the second resin layer and the mask layer are formed on the second surface, and the conductive layer and the through hole opening on the second surface are covered with the second resin layer and the mask layer.

  Subsequently, the second resin layer removing liquid is supplied from the first surface to remove the second resin layer on the through hole on the second surface and the periphery of the through hole, and the conductive layer on the periphery of the through hole on the second surface. To expose. As a result, there is no need for alignment on the second surface without affecting the favorable opening of the first resin layer on the first surface that has already been formed. The layer can be exposed. In addition, by controlling the removal conditions with the second resin layer removing liquid, it is possible to control the removal status of the second resin layer on the through hole and in the periphery of the through hole, and the exposure of the conductive layer in the periphery of the through hole. The width can be controlled to a desired value.

  Thereafter, the mask layer on the second surface is removed, and the resin layer in the through holes and the periphery of the through holes on the first surface and the second surface is removed and opened (hereinafter referred to as an opening substrate with resin). Is produced. By including a series of processes including this process and combining the ink filling process, conductive ink filling process, electrodeposition process, metal plating process, resist formation process, etching process, etc. as appropriate, land of uniform and arbitrary width It is possible to manufacture a circuit board having a through-hole having.

  In the circuit board manufacturing method (2) of the present invention, an opening substrate with resin is produced by the method (1), and an etching resist layer is formed on the exposed conductive layer on the substrate. Thereby, the etching resist layer can be stably formed on the inner wall of the through hole and the periphery of the through hole. By forming the etching resist layer on the inner wall of the through hole and the periphery of the through hole separately from the formation of the wiring pattern on the surface, the necessary and sufficient etching resist layer is formed on the conductive layer in the through hole and the periphery of the through hole. Thus, the conduction reliability and structural strength of the through hole are guaranteed. Further, since the thickness and the like can be selected in accordance with the required quality of the circuit board in the etching resist layer for forming the wiring pattern on the surface, the wiring pattern on the surface can be satisfactorily formed.

  Then, after removing the first resin layer and the second resin layer, a photocrosslinkable resin layer for forming a wiring pattern is formed on the surfaces of the first surface and the second surface. Subsequently, the photocrosslinkable resin layers on the first surface and the second surface are subjected to pattern exposure, and photocrosslinked and cured into a pattern. Thereafter, the uncured photocrosslinkable resin layer on the first surface and the second surface is removed, the conductive layer is exposed in a pattern, and the exposed conductive layers on the first surface and the second surface are removed by etching with an etchant. Thereafter, the etching resist layer in the through hole and in the periphery of the through hole and the photocrosslinked and cured photocrosslinkable resin layer on the first surface and the second surface are removed. By this step, a circuit board having a through hole having a uniform land having an arbitrary width can be satisfactorily manufactured by the subtractive method. In addition, the thickness of the conductive layer can be set to a desired thickness at the stage of substrate preparation, a sufficient thickness of the copper circuit can be secured, and a circuit board having a reliable wiring pattern can be produced. it can.

  In both the first surface and the second surface, before the step of pattern exposure of the photocrosslinkable resin layer, the through hole and the conductive layer around the through hole are in a state where an etching resist layer is formed. Therefore, a good land shape can be ensured even if the peripheral portion of the through hole is not exposed in the pattern exposure step. In other words, the landless and narrow land widths can be accurately and reliably formed without aligning, and the excellent effect of widening the allowable range of alignment during pattern exposure is brought about.

  In the circuit board manufacturing method (3) of the present invention, the first resin layer and the second resin layer are made of a photocrosslinkable resin, and the resistance treatment is an exposure process, so that the circuit board can be used by utilizing existing equipment. Can be manufactured.

  In the manufacturing method (4) of the circuit board of the present invention, the metal layer functions as a good etching resist layer by forming a metal layer insoluble in the etching solution on the wiring portion by pattern plating, and then, by etching, A good wiring pattern is formed.

  In the circuit board manufacturing method (5) according to the present invention, the mask layer on the first surface is removed before the first resin layer is subjected to the resistance-enhancing process. As a result, when it is necessary to perform additional processing such as cleaning and drying in the through-hole after the removal step of the first resin layer, or when the mask layer may adversely affect the resistance-improving processing In this case, the anxiety factor due to the mask layer is removed.

  In the circuit board manufacturing method (6) of the present invention, the mask layer on the first surface is removed after the formation of the second resin layer and the mask layer on the second surface. As a result, when the second resin layer and the mask layer are formed on the second surface, the mask layer on the first surface is protected in the case where there is a possibility that the first surface may be scratched or adhered to the first surface. Will also play a role.

  As described above, in the method for manufacturing a circuit board according to the present invention, the existing manufacturing equipment is used, and it is not necessary to introduce new equipment. Even if it is a simple construction method such as a subtractive method, the through hole and the through hole are used. An excellent effect is obtained that an etching resist layer can be accurately and stably formed in the peripheral portion, and the land width can be arbitrarily controlled. In addition, an etching resist film that has been conventionally required to be thick for tenting can be thinned, which is advantageous in forming a fine pattern.

  Hereinafter, the circuit board manufacturing method of the present invention will be described in detail.

  In the method (1) for producing a circuit board according to the present invention, first, the first surface of the insulating substrate 1 having a through hole as shown in FIG. 1, the second surface opposite to the first surface, and the inner wall of the through hole are provided. An insulating substrate having the conductive layer 12 is prepared. Subsequently, the first resin layer 21 and the mask layer 6 are formed on the first surface, and the conductive layer 12 and the through hole opening on the first surface are covered with the first resin layer 21 and the mask layer 6 (FIG. 2). Thereafter, the first resin layer on the through hole in the first surface and the periphery of the through hole is removed by the first resin layer removing liquid supplied from the surface opposite to the first surface (referred to as the second surface) (FIG. 3). At this time, the removal amount of the first resin layer on the through hole on the first surface and in the periphery of the through hole can be adjusted, and the exposed width of the conductive layer 12 can be controlled. Thereafter, the first resin layer is subjected to a resistance treatment, the first resin layer 23 after the resistance treatment is formed, and resistance to the subsequent second resin layer removal liquid is imparted (FIG. 4).

The second resin layer 22 and the mask layer 7 are also formed on the second surface by the same method as that applied to the first surface (FIG. 5). After removing the mask layer 6 on the first surface (FIG. 6), the removal liquid is supplied from the first surface, and the second resin layer on the through hole on the second surface and around the through hole is passed through the through hole. Dissolve and remove (FIG. 7). At this time, similarly to the treatment of the first surface, the removal amount of the second resin layer on the through hole on the second surface and the periphery of the through hole can be adjusted, and the exposed width of the conductive layer 12 is controlled. Can do. If necessary, after cleaning and drying, the mask layer 7 on the second surface is removed (FIG. 8). As a result, an opening substrate with a resin whose opening width is controlled to a desired width can be manufactured, and then a hole filling ink process, a conductive ink filling process, an electrodeposition process, a metal plating process, a resist formation process, and an etching process are performed. A circuit board having a landless or narrow land-width hole can be manufactured through a series of processes appropriately combined. In addition, in the case where the second resin layer and / or the first resin layer is eroded with respect to the treatment liquid in the subsequent process, the second resin layer and / or the first resin layer is added as necessary. By performing each resistance process, resistance to the subsequent steps can be imparted (FIG. 9).
The removal of the mask layer 6 on the first surface may be performed before the endurance treatment of the first resin layer or after the formation of the second resin layer and the mask layer on the second surface. . As a result, it is possible to expect an effect that the anxiety factor due to the mask layer is removed and that the mask layer on the first surface can also play a protective role.

  As the first resin layer and the second resin layer (hereinafter collectively referred to as “resin layer”) according to the present invention, a first resin layer removing liquid and a second resin layer removing liquid (hereinafter collectively referred to as “resin layer”), respectively. The resin is not particularly limited as long as it is a resin that can be dissolved and removed by a “removal solution”. Acrylic resin, vinyl acetate resin, vinyl chloride resin, vinylidene chloride resin, vinyl acetal resin such as polyvinyl butyral, polystyrene, polyethylene, polypropylene and its chloride, polyester resin such as polyethylene terephthalate and polyethylene isophthalate, polyamide resin, vinyl modified alkyd Resins such as resins, phenol resins, xylene resins, polyimide resins, epoxy resins, gelatin, carboxymethyl cellulose, and other cellulose ester derivatives can be used. Moreover, the photocrosslinkable resin described below can also be used as the resin layer. Even if these resins are the same type of resin, the solubility varies depending on the type and amount of the functional groups contained in the resin and the difference in molecular weight.

  In the present invention, examples of the photocrosslinkable resin that can be used as the resin layer include a photocrosslinkable dry film photoresist for manufacturing a circuit board. Examples will be given below, but any photocrosslinkable resin layer can be applied as long as it does not differ from the gist of the present invention. For example, a negative photosensitive resin composition comprising a binder polymer containing a carboxylic acid group, a photopolymerizable polyfunctional monomer, a photopolymerization initiator, a solvent, and other additives can be used. Their blending ratio is determined in accordance with required properties such as sensitivity, resolution, hardness, tenting property and the like. Examples of these include “Photopolymer Handbook” (edited by Photopolymer Social Society, Kogyo Kenkyukai, 1989) and “Photopolymer Technology” (edited by Yamao Ao, Nagamatsu Mototaro, Nikkan Kogyo Shimbun, 1988). It is described in. As commercial products, for example, Liston from DuPont MRC Dry Film Co., Ltd., Fotec from Hitachi Chemical Co., Ltd., Sunfort from Asahi Kasei Electronics Co., Ltd. can be used. In the commercial product, the photocrosslinkable resin film is sandwiched between a support film such as a polyester film and a protective film such as a polyethylene film.

  As the first resin layer removing liquid and the second resin layer removing liquid according to the present invention, any liquid that can dissolve or disperse the resin layer can be used, and a liquid suitable for the composition of the resin layer to be used is used. When a commercially available dry film resist is used as the resin layer, generally an alkaline aqueous solution is usefully used. For example, alkali metal silicate, alkali metal hydroxide, phosphoric acid or alkali metal carbonate is used. An aqueous solution of an inorganic basic compound such as a salt, phosphoric acid or ammonium carbonate, an organic basic compound such as ethanolamines, ethylenediamine, propanediamine, triethylenetetramine, morpholine, or the like can be used. These aqueous solutions need to be adjusted in concentration, temperature, spray pressure and the like.

  When using an aqueous alkali solution as the resin layer removing solution, the resin layer removing solution can be dissolved and removed by using a resin having high solubility in the aqueous alkaline solution as the resin layer. When an alkaline aqueous solution is used as the resin layer removing solution, a resin having an acid value of 1 mgKOH / g or more, more preferably 10 mgKOH / g or more can be suitably used as the resin layer. When an alkaline aqueous solution is used as the resin layer removing liquid, the resin layer includes monomers having a carboxylic acid group, a methacrylic acid amide, a phenolic hydroxyl group, a sulfonic acid group, a sulfonamide group, a sulfonimide group, and a phosphonic acid group. Examples thereof include a copolymer, a phenol resin, and a xylene resin. Specific examples include styrene / maleic acid monoalkyl ester copolymer, methacrylic acid / methacrylic acid ester copolymer, styrene / methacrylic acid / methacrylic acid ester copolymer, acrylic acid / methacrylic acid ester copolymer, Methacrylic acid / methacrylic acid ester / acrylic acid ester copolymer, styrene / methacrylic acid / acrylic acid ester copolymer, styrene / acrylic acid / methacrylic acid ester copolymer, vinyl acetate / crotonic acid copolymer, vinyl acetate / Crotonic acid / methacrylic acid ester copolymer, vinyl benzoate / acrylic acid / methacrylic acid ester copolymer such as styrene, acrylic ester, methacrylate, vinyl acetate, vinyl benzoate and the above carboxylic acid-containing monomer The copolymer of these is mentioned. These resins may be used alone or in combination of two or more. Moreover, if the solubility with respect to the resin layer removal liquid is ensured, another additive can also be added.

  As the resistance-improving treatment of the first resin layer according to the present invention, any treatment is possible as long as the treatment is changed to a state insoluble or hardly soluble in the second resin layer removal liquid. is there. A curing treatment with light or heat is preferably used because of its simplicity. As the first resin layer, a photocrosslinkable resin or a thermosetting resin can be used.

  When using an aqueous alkali solution as the resin layer removal liquid, the first resin layer is dissolved in the first resin layer removal liquid by using an alkali-soluble resin and adding a photocrosslinkable component. After the chemical conversion treatment, it can be insoluble or hardly soluble in the second resin layer removing solution. Moreover, by applying a thermosetting component such as an epoxy resin and performing the resistance treatment by heat treatment, it is dissolved in the first resin layer removal liquid before the resistance treatment, but after the resistance treatment, It can be made insoluble or hardly soluble in the two resin layer removing liquid.

  In addition, when the second resin layer removal liquid is a liquid having a lower pH than the first resin layer removal liquid, the second resin layer removal liquid can be used with respect to the second resin layer removal liquid without performing the resistance treatment of the first resin layer. Thus, the first resin layer can be prevented from being dissolved. In that case, the first resin layer can be made resistant.

  The second resin layer according to the present invention needs to be a resin having resistance to the treatment liquid in the process after the opening substrate with resin is produced. If necessary, a light-proofing or heat-resistant treatment is performed. When pattern plating is used for forming the etching resist layer, a resin resistant to the plating solution is used.

  As the mask layer according to the present invention, a resin or metal that is insoluble or hardly soluble in the resin layer removing liquid can be used. As the resin, acrylic resin, vinyl acetate resin, vinyl chloride resin, vinylidene chloride resin, vinyl acetal resin such as polyvinyl butyral, polystyrene, polyethylene, polypropylene and its chloride, polyester resin such as polyethylene terephthalate and polyethylene isophthalate, polyamide Resins such as resins, vinyl-modified alkyd resins, phenol resins, xylene resins, polyimide resins, gelatin, and cellulose ester derivatives such as carboxymethyl cellulose can be used. From the viewpoint of versatility, a polyester resin, a polyimide resin, or the like can be preferably used. Copper, aluminum, etc. can be used as a metal. If the mask layer is formed in a film shape and integrated with the resin layer on the substrate, it is preferable because the resin layer and the mask layer can be easily and stably formed in the process. When the above-mentioned dry film photoresist is used, the support film can be used as it is as a mask layer, which is preferable. Even if these resins are the same type of resin, the solubility varies depending on the type and amount of the functional groups contained in the resin and the difference in molecular weight. When using alkaline aqueous solution as a resin layer removal liquid, it becomes insoluble or hardly soluble in resin layer removal liquid by using resin with low solubility with respect to alkaline aqueous solution among these resins as a mask layer. When an aqueous alkali solution is used as the resin layer removing liquid, a resin having an acid value of the mask layer that is one-tenth or less, preferably one-hundredth or less of the acid value of the resin can be suitably used.

  As the insulating substrate according to the present invention, a paper substrate phenol resin or glass substrate epoxy resin substrate, a polyester film, a polyimide film, a liquid crystal polymer film, or the like can be used. As the conductive layer, copper, silver, gold, aluminum, stainless steel, 42 alloy, nichrome, tungsten, ITO, conductive polymer, various metal complexes, and the like can be used. Examples of these are described in “Handbook of Printed Circuit Technology” (edited by Japan Printed Circuit Industry Association, Nikkan Kogyo Shimbun, 1987).

  As a method for providing a conductive layer on an insulating substrate according to the present invention, a sputtering method, a vapor deposition method, an electroless plating method, an electrolytic plating method, a method of attaching an ultrathin conductive layer such as a metal foil to an insulating substrate, A method of forming a conductive layer of a laminated plate with the layers laminated into a thin film by etching treatment or the like can be used alone or in combination. After opening a through hole in the insulating substrate, a conductive layer can be provided on the surface of the insulating substrate and the inner wall of the through hole, or a copper-clad laminate provided with a conductive layer in advance on the insulating substrate surface, A through hole may be formed, and a conductive layer may be provided on the inner wall of the through hole by electroless plating and electrolytic plating.

  For the electroless plating treatment and the electrolytic plating treatment according to the present invention, for example, those described in "Handbook of Printed Circuit Technology" (edited by Japan Printed Circuit Industry Association, Nikkan Kogyo Shimbun, 1987) should be used. Can do.

  In the circuit board manufacturing method (2) of the present invention, after the resin-made opening substrate is manufactured, the circuit board is manufactured by a subtractive method.

  An etching resist layer 13 is formed on the exposed conductive layer of the resin-coated opening substrate (FIG. 10). Then, after removing the resin layers on the first surface and the second surface (FIG. 11), a photocrosslinkable resin layer 28 is formed on the first surface and the second surface (FIG. 12). Subsequently, pattern exposure is performed to photocrosslink and cure into a pattern (FIG. 13), uncured portions are removed by development processing, and an etching resist layer made of photocrosslinkable resin 29 is formed (FIG. 14). ).

  Next, the exposed portion of the conductive layer 12 is removed by etching (FIG. 15). Finally, the etching resist layer 13 made of the etching resist layer 13 in the through-hole portion and the photocrosslinkable resin 29 that has been photocrosslinked and cured on the surface is removed to produce a circuit board (FIG. 16).

  As a method for forming an etching resist layer on the conductive layer according to the present invention, an electrodeposition means or a plating method can be used. When using copper as the conductive layer and plating metal as the etching resist layer, gold, tin, tin-lead solder alloy, nickel, tin-nickel alloy, nickel-gold alloy, silver, zinc, palladium, ruthenium Rhodium, etc. can be used. An electrodeposition resin can also be used as the etching resist layer. In this case, the resin has an electric charge to enable electrodeposition. Specific examples include resin emulsions such as polyimide, epoxy, acrylic, polyester, fluorine, and silicon. Can be used. The retained charge can be used in either an anionic type or a cationic type. Examples of the anionic type include a carboxyl group, a sulfonic acid group, or an anionic group thereof. Examples of the cationic type include an amino group, its cationic group, and further. The quaternary ionic group etc. are mentioned.

  Examples of the photocrosslinkable resin layer related to the circuit board production method (2) of the present invention include a binder polymer containing a carboxylic acid group, a photopolymerizable polyfunctional monomer, a photopolymerization initiator, a solvent, and other additives. A negative photosensitive resin composition comprising: Their blending ratio is determined in accordance with required properties such as sensitivity, resolution, hardness, tenting property and the like. Examples of these include “Photopolymer Handbook” (edited by Photopolymer Social Society, Kogyo Kenkyukai, 1989) and “Photopolymer Technology” (edited by Yamao Ao, Nagamatsu Mototaro, Nikkan Kogyo Shimbun, 1988). It is described in. As commercial products, for example, Liston from DuPont MRC Dry Film Co., Ltd., Fotec from Hitachi Chemical Co., Ltd., Sunfort from Asahi Kasei Electronics Co., Ltd. can be used. In the commercial product, the photocrosslinkable resin film is sandwiched between a support film such as a polyester film and a protective film such as a polyethylene film.

  The pattern exposure according to the present invention is performed by direct laser writing, contact exposure through a photomask, proximity exposure, projection exposure, or the like. As the light source, in addition to various laser light sources, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a metal halide lamp, a xenon lamp, or the like can be used. By this pattern exposure, the photocrosslinkable resin in the circuit portion is photocrosslinked and cured (FIG. 13). At this time, since the land portion is already protected by the etching resist layer 13, it is not necessary to expose the land portion.

  Any etching solution may be used as long as it can dissolve and remove the conductive layer 12. For example, an alkaline etching solution such as alkaline ammonia, or a general etching solution such as sulfuric acid-hydrogen peroxide, cupric chloride, persulfate, or ferric chloride can be used. When the conductive layer is copper, the metal plating etching resist is used for the through-hole part, and the dry film photoresist is used as the etching resist layer for the wiring pattern part on the surface, both of them are resistant, and the copper is etched well. A commercially available alkaline etching solution, ammonium persulfate, hydrogen peroxide / sulfuric acid and the like are preferably used. As the apparatus or method, for example, an apparatus or method such as horizontal spray etching or immersion etching can be used. These details are described in “Printed Circuit Technology Handbook” (edited by Japan Printed Circuit Industry Association, Nikkan Kogyo Shimbun, 1987).

  In the method for producing a circuit board of the present invention, examples of a method for removing the photocrosslinkable photocrosslinkable resin layer used as an etching resist layer include a method of removing with a high pH alkaline aqueous solution, an organic solvent or the like. Specific examples include strong alkaline aqueous solutions containing sodium hydroxide, potassium hydroxide, sodium metasilicate, and the like, and organic solvents such as alcohols and ketones.

  In addition, the metal plating etching resist in the through-hole portion can be removed by using an acid-based treatment liquid such as nitric acid, sulfuric acid, or cyan that is commercially available for solder removal.

  Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited to these examples.

  Using a 200 × 200 × 0.1 mm copper-clad laminate using a 12 μm thick copper foil, a plurality of through-holes with a diameter of 0.10 mm are formed with a drill, and an electroless copper plating process is performed. An electroless copper plating layer having a thickness of about 0.5 μm was formed on the inner wall of the through hole. Thereafter, electrolytic copper plating treatment was performed to form an electrolytic copper plating layer having a thickness of about 12 μm on the inner wall of the hole and the copper of the copper-clad laminate, and an insulating substrate having a conductive layer in the through hole and on the surface was prepared.

  Subsequently, using a laminator for dry film photoresist, a dry film photoresist for circuit formation composed of a 25 μm photocrosslinkable resin layer and a 12 μm mask layer (support film, material: polyester) is applied to one side (first side) A first resin layer (photocrosslinkable resin layer) and a mask layer (support film) were provided by thermocompression bonding to the first surface.

  Next, using a 1% by mass aqueous sodium carbonate solution (30 ° C.), the first resin layer removal solution was applied to the second surface side of the substrate at a spray pressure of 0.2 MPa for 50 seconds to penetrate the first surface. The photocrosslinkable resin layer on the hole and around the through hole was dissolved and removed. When the through hole and the periphery of the through hole were observed with an optical microscope, the photocrosslinkable resin layer in the periphery of the through hole was removed concentrically with the through hole. The outer diameter of the exposed copper portion around the through hole was 110 μm.

  Next, the first resin layer on the first surface is exposed to the entire surface for 45 seconds using a high pressure mercury lamp light source device for baking (Unirec URM300, manufactured by USHIO INC.), Followed by photocrosslinking curing. The resistance process with respect to the 2nd resin layer removal liquid was performed.

  Next, using the dry film photoresist laminator on the second surface of the substrate after the exposure processing, a circuit-forming dry film photoresist similar to that used for the first surface is thermocompression bonded, and the second resin A layer and a mask layer were provided. Thereafter, the mask layer on the first surface was peeled off and removed.

  Next, using a 1% by mass aqueous solution of sodium carbonate (30 ° C.), shower spray was applied for 50 seconds at a spray pressure of 0.2 MPa from the first surface side of the substrate, and on and through the through holes on the second surface. The second resin layer around the hole was dissolved and removed. Thereafter, the mask layer on the second surface was removed, and an aperture substrate with resin was produced. When the through hole on the second surface and the periphery of the through hole were observed with an optical microscope, the photocrosslinkable resin layer in the periphery of the through hole was removed concentrically with the through hole. The outer diameter of the exposed copper portion around the through hole was 110 μm.

  Using a 200 × 200 × 0.1 mm copper-clad laminate using a 12 μm thick copper foil, a plurality of through-holes with a diameter of 0.10 mm are formed with a drill, and an electroless copper plating process is performed. An electroless copper plating layer having a thickness of about 0.5 μm was formed on the inner wall of the through hole.

  Subsequently, using a laminator for dry film photoresist, a dry film photoresist for circuit formation composed of a 25 μm photocrosslinkable resin layer and a 12 μm mask layer (support film, material: polyester) is applied to one side (first side) A first resin layer (photocrosslinkable resin layer) and a mask layer (support film) were provided by thermocompression bonding to the first surface.

  Next, using a first resin layer removing solution of 1% by mass sodium carbonate aqueous solution (30 ° C.), shower spray was applied for 32 seconds from the second surface side of the substrate at a spray pressure of 0.2 MPa to penetrate the first surface. The photocrosslinkable resin layer on the hole and around the through hole was dissolved and removed. When the through hole and the peripheral part of the through hole were observed with an optical microscope, the photocrosslinkable resin layer in the peripheral part of the through hole was removed concentrically with the through hole, and the outer diameter of the copper exposed part in the peripheral part of the through hole was 140 μm.

  Next, the first resin layer on the first surface is exposed to the entire surface for 45 seconds using a high pressure mercury lamp light source device for baking (Unirec URM300, manufactured by USHIO INC.), Followed by photocrosslinking curing. The resistance process with respect to the 2nd resin layer removal liquid was performed.

  Next, using the dry film photoresist laminator on the second surface of the substrate after the exposure processing, a circuit-forming dry film photoresist similar to that used for the first surface is thermocompression bonded, and the second resin A layer and a mask layer were provided. Thereafter, the mask layer on the first surface was peeled off and removed.

  Next, using a removing solution of 1% by mass sodium carbonate aqueous solution (30 ° C.), shower spray was applied for 33 seconds from the first surface side of the substrate at a spray pressure of 0.2 MPa to penetrate and penetrate the through hole on the second surface. The second resin layer around the hole was dissolved and removed. Thereafter, the mask layer on the second surface was removed, and an aperture substrate with resin was produced. When the through hole on the second surface and the periphery of the through hole were observed with an optical microscope, the photocrosslinkable resin layer in the periphery of the through hole was removed concentrically with the through hole, and the exposed copper portion in the periphery of the through hole The outer diameter of was 140 μm.

  Next, the entire surface of the second resin layer on the second surface is exposed for 45 seconds using a high pressure mercury lamp light source device (Unirec URM300, manufactured by USHIO ELECTRIC CO., LTD.) For baking, and then the entire surface is photocrosslinked and cured. Strengthened resistance to electrolytic copper plating treatment.

  Next, electrolytic copper plating treatment was performed, and an electrolytic copper plating layer having a thickness of about 12 μm was formed on the inner wall of the hole and the exposed copper portion on the surface. An opening substrate with resin was produced in which the copper thickness of the inner wall of the hole was increased without increasing the copper thickness of the circuit forming portion on the surface.

  Using a 200 × 200 × 0.1 mm copper-clad laminate using a 12 μm thick copper foil, a plurality of through-holes with a diameter of 0.10 mm are formed with a drill, and an electroless copper plating process is performed. An electroless copper plating layer having a thickness of about 0.5 μm was formed on the inner wall of the through hole. Thereafter, electrolytic copper plating treatment was performed to form an electrolytic copper plating layer having a thickness of about 12 μm on the inner wall of the hole and the copper of the copper-clad laminate, and an insulating substrate having a conductive layer in the through hole and on the surface was prepared.

  Subsequently, using a laminator for dry film photoresist, a dry film photoresist for circuit formation composed of a 25 μm photocrosslinkable resin layer and a 12 μm mask layer (support film, material: polyester) is applied to one side (first side) A first resin layer (photocrosslinkable resin layer) and a mask layer (support film) were provided by thermocompression bonding to the first surface.

  Next, using a first resin layer removing solution of 1% by mass aqueous sodium carbonate (30 ° C.), shower spray was applied for 65 seconds from the second surface side of the substrate at a spray pressure of 0.2 MPa to penetrate the first surface. The photocrosslinkable resin layer on the hole and around the through hole was dissolved and removed. When the through hole and the peripheral part of the through hole were observed with an optical microscope, the photocrosslinkable resin layer in the peripheral part of the through hole was removed concentrically with the through hole, and the outer diameter of the copper exposed part in the peripheral part of the through hole was 126 μm.

  Next, the first resin layer on the first surface is exposed to the entire surface for 45 seconds using a high pressure mercury lamp light source device for baking (Unirec URM300, manufactured by USHIO INC.), Followed by photocrosslinking curing. The resistance process with respect to the 2nd resin layer removal liquid was performed.

  Next, using the dry film photoresist laminator on the second surface of the substrate after the exposure processing, a circuit-forming dry film photoresist similar to that used for the first surface is thermocompression bonded, and the second resin A layer and a mask layer were provided. Thereafter, the mask layer on the first surface was peeled off and removed.

  Next, using a 1% by mass aqueous solution of sodium carbonate (30 ° C.), shower spray was applied for 65 seconds at a spray pressure of 0.2 MPa from the first surface side of the substrate, and on and through the through holes on the second surface. The second resin layer around the hole was dissolved and removed. Thereafter, the mask layer on the second surface was removed, and an aperture substrate with resin was produced. When the through hole on the second surface and the periphery of the through hole were observed with an optical microscope, the photocrosslinkable resin layer in the periphery of the through hole was removed concentrically with the through hole. The outer diameter of the exposed copper portion around the through hole was 126 μm.

  Using a 200 × 200 × 0.1 mm copper-clad laminate using a 12 μm thick copper foil, a plurality of through-holes with a diameter of 0.10 mm are formed with a drill, and an electroless copper plating process is performed. An electroless copper plating layer having a thickness of about 0.5 μm was formed on the inner wall of the through hole. Thereafter, electrolytic copper plating treatment was performed to form an electrolytic copper plating layer having a thickness of about 12 μm on the inner wall of the hole and the copper of the copper-clad laminate, and an insulating substrate having a conductive layer in the through hole and on the surface was prepared.

  Subsequently, using a laminator for dry film photoresist, a dry film photoresist for circuit formation composed of a 25 μm photocrosslinkable resin layer and a 12 μm mask layer (support film, material: polyester) is applied to one side (first side) A first resin layer (photocrosslinkable resin layer) and a mask layer (support film) were provided by thermocompression bonding to the first surface.

  Next, using a 1% by mass aqueous sodium carbonate solution (30 ° C.), the first resin layer removing solution was applied to the second surface side of the substrate at a spray pressure of 0.2 MPa for 80 seconds to penetrate the first surface. The photocrosslinkable resin layer on the hole and around the through hole was dissolved and removed. When the through hole and the peripheral part of the through hole were observed with an optical microscope, the photocrosslinkable resin layer in the peripheral part of the through hole was removed concentrically with the through hole, and the outer diameter of the copper exposed part in the peripheral part of the through hole was 138 μm.

  Next, the first resin layer on the first surface is exposed to the entire surface for 45 seconds using a high pressure mercury lamp light source device for baking (Unirec URM300, manufactured by USHIO INC.), Followed by photocrosslinking curing. The resistance process with respect to the 2nd resin layer removal liquid was performed.

  Next, using the dry film photoresist laminator on the second surface of the substrate after the exposure processing, a circuit-forming dry film photoresist similar to that used for the first surface is thermocompression bonded, and the second resin A layer and a mask layer were provided. Thereafter, the mask layer on the first surface was peeled off and removed.

  Next, using a 1% by mass aqueous solution of sodium carbonate (30 ° C.), shower spray is applied for 80 seconds from the first surface side of the substrate at a spray pressure of 0.2 MPa, and the through holes on the second surface and through the surface. The second resin layer around the hole was dissolved and removed. Thereafter, the mask layer on the second surface was removed, and an aperture substrate with resin was produced. When the through hole on the second surface and the periphery of the through hole were observed with an optical microscope, the photocrosslinkable resin layer in the periphery of the through hole was removed concentrically with the through hole. The outer diameter of the exposed copper portion around the through hole was 138 μm.

  Using the baking high pressure mercury lamp light source device (Unirec URM300, manufactured by USHIO INC.) On the second surface of the resin-coated opening substrate obtained in Example 1, the entire surface is exposed for 45 seconds to photocrosslink and cure the entire surface. Then, resistance treatment for the processing liquid for forming the etching resist layer was performed. Next, tin plating was formed as an etching resist layer on the exposed copper surface with a tin plating solution (Solderon SN-2670 manufactured by Meltex).

  Next, the photocrosslinked and cured photocrosslinked resin layer of the first resin layer and the second resin layer was removed using a 3% by mass aqueous sodium hydroxide solution (30 ° C.).

  Next, using a laminator for dry film photoresist, a dry film photoresist for circuit formation comprising a 15 μm photocrosslinkable resin layer and a 12 μm mask layer (support film, material: polyester) is heated on both sides of the substrate. Crimped. A photomask (conductor width and gap: 40 μm) on which a wiring pattern is drawn is placed on the second surface of the substrate, and ultraviolet light is used for 40 seconds using a baking high pressure mercury lamp light source device (Unirec URM300, manufactured by USHIO INC.) Having a suction adhesion mechanism. Pattern exposure was performed. Thereafter, the support films on both sides were removed, and then an alkali development treatment with a 1% by mass aqueous sodium carbonate solution (30 ° C.) was performed to form an etching resist layer made of a photocrosslinkable resin that was photocrosslinked and cured on both sides of the substrate.

  Next, the exposed copper was removed using an ammonia alkali etchant (A process manufactured by Meltex Co.) as an etchant. Thereafter, the etching resist layer made of the photocrosslinkable and cured photocrosslinkable resin is removed using a 3% by mass aqueous sodium hydroxide solution (30 ° C.). The circuit board was manufactured by peeling off using (Mentex Enstrip TL). When the circuit board was observed with a microscope, the land was formed concentrically with the through hole, the land width Lw was 5 μm, the circuit board was not disconnected, and a circuit board having a good narrow land width was produced. I was able to.

  Tin plating was formed on the exposed copper surface as an etching resist layer on the exposed substrate with resin obtained in Example 2 by a tin plating solution (Solderon SN-2670 manufactured by Meltex Co., Ltd.).

  Next, the photocrosslinked and cured photocrosslinked resin layer of the first resin layer and the second resin layer was removed using a 3% by mass aqueous sodium hydroxide solution (30 ° C.).

  Next, using a laminator for dry film photoresist, a dry film photoresist for circuit formation comprising a 15 μm photocrosslinkable resin layer and a 12 μm mask layer (support film, material: polyester) is heated on both sides of the substrate. Crimped. A photomask (conductor width and gap: 30 μm) on which a wiring pattern is drawn is placed on the second surface of the substrate, and ultraviolet light is used for 40 seconds using a baking high pressure mercury lamp light source device (Unirec URM300, manufactured by USHIO INC.) Having a suction adhesion mechanism. Pattern exposure was performed. Thereafter, the support films on both sides were removed, and then an alkali development treatment with a 1% by mass aqueous sodium carbonate solution (30 ° C.) was performed to form an etching resist layer made of a photocrosslinkable resin that was photocrosslinked and cured on both sides of the substrate.

  Next, the exposed copper was removed using an ammonia alkali etchant (A process manufactured by Meltex Co.) as an etchant. Thereafter, the etching resist layer made of the photocrosslinkable and cured photocrosslinkable resin is removed using a 3% by mass aqueous sodium hydroxide solution (30 ° C.). The circuit board was manufactured by peeling off using (Mentex Enstrip TL). When the circuit board was observed with a microscope, the land was formed concentrically with the through hole, the land width Lw was 20 μm, the circuit board had no disconnection, and a circuit board having a good narrow land width was produced. I was able to.

  Using the high pressure mercury lamp light source device for baking (Unirec URM300, manufactured by USHIO Inc.) on the second surface of the resin-coated aperture substrate obtained in Example 3, the entire surface is exposed for 45 seconds to photocrosslink and cure the entire surface. Then, resistance treatment for the processing liquid for forming the etching resist layer was performed. Next, tin plating was formed as an etching resist layer on the exposed copper surface with a tin plating solution (Solderon SN-2670 manufactured by Meltex).

  Next, the photocrosslinked and cured photocrosslinked resin layer of the first resin layer and the second resin layer was removed using a 3% by mass aqueous sodium hydroxide solution (30 ° C.).

  Next, using a laminator for dry film photoresist, a dry film photoresist for circuit formation comprising a 15 μm photocrosslinkable resin layer and a 12 μm mask layer (support film, material: polyester) is heated on both sides of the substrate. Crimped. A photomask (conductor width and gap: 40 μm) on which a wiring pattern is drawn is placed on the second surface of the substrate, and ultraviolet light is used for 40 seconds using a baking high pressure mercury lamp light source device (Unirec URM300, manufactured by USHIO INC.) Having a suction adhesion mechanism. Pattern exposure was performed. Thereafter, the support films on both sides were removed, and then an alkali development treatment with a 1% by mass aqueous sodium carbonate solution (30 ° C.) was performed to form an etching resist layer made of a photocrosslinkable resin that was photocrosslinked and cured on both sides of the substrate.

  Next, the exposed copper was removed using an ammonia alkali etchant (A process manufactured by Meltex Co.) as an etchant. Thereafter, the etching resist layer made of the photocrosslinkable and cured photocrosslinkable resin is removed using a 3% by mass aqueous sodium hydroxide solution (30 ° C.). The circuit board was manufactured by peeling off using (Mentex Enstrip TL). When the circuit board was observed with a microscope, the land was formed concentrically with the through hole, the land width Lw was 13 μm, the circuit board had no disconnection, and a circuit board having a good narrow land width was produced. I was able to.

  Using the high pressure mercury lamp light source device for baking (Unirec URM300, manufactured by USHIO) on the second surface of the resin-coated opening substrate obtained in Example 4, the entire surface is exposed for 45 seconds to photocrosslink and cure the entire surface. Then, resistance treatment for the processing liquid for forming the etching resist layer was performed. Next, tin plating was formed as an etching resist layer on the exposed copper surface with a tin plating solution (Solderon SN-2670 manufactured by Meltex).

  Next, the photocrosslinked and cured photocrosslinked resin layer of the first resin layer and the second resin layer was removed using a 3% by mass aqueous sodium hydroxide solution (30 ° C.).

  Next, using a laminator for dry film photoresist, a dry film photoresist for circuit formation comprising a 15 μm photocrosslinkable resin layer and a 12 μm mask layer (support film, material: polyester) is heated on both sides of the substrate. Crimped. A photomask (conductor width and gap: 40 μm) on which a wiring pattern is drawn is placed on the second surface of the substrate, and ultraviolet light is used for 40 seconds using a baking high pressure mercury lamp light source device (Unirec URM300, manufactured by USHIO INC.) Having a suction adhesion mechanism. Pattern exposure was performed. Thereafter, the support films on both sides were removed, and then an alkali development treatment with a 1% by mass aqueous sodium carbonate solution (30 ° C.) was performed to form an etching resist layer made of a photocrosslinkable resin that was photocrosslinked and cured on both sides of the substrate.

  Next, the exposed copper was removed using an ammonia alkali etchant (A process manufactured by Meltex Co.) as an etchant. Thereafter, the etching resist layer made of the photocrosslinkable and cured photocrosslinkable resin is removed using a 3% by mass aqueous sodium hydroxide solution (30 ° C.). The circuit board was manufactured by peeling off using (Mentex Enstrip TL). When the circuit board was observed with a microscope, the land was formed concentrically with the through hole, the land width Lw was 19 μm, the circuit board was not disconnected, and a circuit board having a good narrow land width was produced. I was able to.

  The present invention can be used for manufacturing circuit boards such as printed wiring boards and semiconductor devices.

Sectional drawing which shows 1 process in the method of this invention. Sectional drawing which shows the process following FIG. 1 in the method of this invention. Sectional drawing which shows the process following FIG. 2 in the method of this invention. Sectional drawing which shows the process following FIG. 3 in the method of this invention. Sectional drawing which shows the process following FIG. 4 in the method of this invention. Sectional drawing which shows the process following FIG. 5 in the method of this invention. Sectional drawing which shows the process following FIG. 6 in the method of this invention. Sectional drawing which shows the process following FIG. 7 in the method of this invention. Sectional drawing which shows the process following FIG. 8 in the method of this invention. Sectional drawing which shows the process following FIG. 9 in the method of this invention. Sectional drawing which shows the process following FIG. 10 in the method of this invention. Sectional drawing which shows the process following FIG. 11 in the method of this invention. Sectional drawing which shows the process following FIG. 12 in the method of this invention. Sectional drawing which shows the process following FIG. 13 in the method of this invention. Sectional drawing which shows the process following FIG. 14 in the method of this invention. Sectional drawing which shows the process following FIG. 15 in the method of this invention. 1 is a schematic cross-sectional view showing an example of a multilayer circuit board. The schematic plan view showing a through-hole and a land. Schematic showing the positional deviation of a through-hole and a land.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insulating substrate 2 Conductive layer 6 Mask layer on 1st resin layer 7 Mask layer on 2nd resin layer 12 Conductive layer 13 Etching resist layer 17 Through-hole 18 Land part conductive layer 21 1st resin layer 22 2nd resin layer 23 First Resin Layer After Durability Treatment 24 Second Resin Layer After Durability Treatment 28 Photocrosslinkable Resin Layer 29 Photocrosslinked Cured Photocrosslinkable Resin 31 Through Hole (Through Hole)
32 Viahole 33 Interstitial Viahole

Claims (5)

(A) preparing an insulating substrate having a conductive layer on the first surface of the insulating substrate having a through hole, the second surface opposite to the first surface, and the inner wall of the through hole;
(B) forming a first resin layer and a mask layer on the first surface and covering the conductive layer and the through hole opening on the first surface with the first resin layer and the mask layer;
(C) The first resin layer removing liquid is supplied from the second surface to remove the first resin layer on the through hole on the first surface and the periphery of the through hole, and the conductive layer on the periphery of the through hole on the first surface. Exposing the process,
(D) a step of applying resistance treatment to the second resin layer removing liquid to the resin layer on the first surface;
(E) removing the mask layer on the first surface;
(F) forming a second resin layer and a mask layer on the second surface, and covering the conductive layer and the through hole opening on the second surface with the second resin layer and the mask layer;
(G) The second resin layer removing liquid is supplied from the first surface to remove the second resin layer on the through hole on the second surface and the periphery of the through hole, and the conductive layer on the periphery of the through hole on the second surface. Exposing the process,
(H) removing the mask layer on the second surface;
(I) forming an etching resist layer on the exposed conductive layer;
(J) a step of removing the first resin layer and the second resin layer;
(K) forming a photocrosslinkable resin layer on the first surface and the second surface;
(L) A step of subjecting the photocrosslinkable resin layers on the first surface and the second surface to pattern exposure and photocrosslinking and curing in a pattern,
(M) removing the uncured photocrosslinkable resin layer on the first surface and the second surface and exposing the conductive layer in a pattern;
(N) A step of removing the exposed conductive layers on the first surface and the second surface by etching with an etchant;
(O) a step of removing the etching resist layer and the photocrosslinkable resin layer that has been photocrosslinked and cured;
A method of manufacturing a circuit board including the above in this order. The first resin layer is a light-crosslinkable resin, durability-is exposure processing, manufacturing method of circuit board according to claim 1 Symbol placement. Etching resist layer is not soluble metal layer to the etchant of the conductive layer is formed by pattern plating method of a circuit board according to claim 1 or 2, wherein. (E) performed prior to step (d) is step method of manufacturing a circuit board of any one of claims 1-3. (E) a step after the step (f), method of manufacturing a circuit board of any one of claims 1-3.

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