JP2009182350A - Method of efficiently manufacturing connection substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of efficiently manufacturing a connection substrate. <P>SOLUTION: The connection substrate is manufactured such that a composite metal layer including three metal layers on one face or both faces of a support substrate is arranged; after temporarily fixed by heating and pressing, a part of the composite metal layer is selectively removed to form a connecting conductor; an insulation resin composition layer is formed so as to cover side faces of the obtained connecting conductor; then, the insulation resin composition layer is polished so that the connecting conductor is exposed; the composite metal layer formed so that the connecting conductor passes through in a direction of the insulation resin composition layer is peeled off from the support substrate; and remaining metal layers are selectively removed to form conductor circuits. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a connection board, and a method for manufacturing a multilayer wiring board using the connection board.

  In recent years, the social environment surrounding us has changed greatly with the development of information and communication networks. Among them is the growth of mobile devices, and the market is expanding with miniaturization and high functionality. For this reason, further miniaturization of semiconductor packages and a multilayer wiring board capable of mounting them at high density are required, and interlayer connection capable of high-density wiring, that is, high-density multilayer technology is important.

  As a main multilayering method, there is a through-hole connection combining drilling and plating processes, which is widely known. However, since holes are formed in all layers, the wiring capacity is limited.

  Therefore, in order to reduce the hole volume of the connection part, a build-up technique that repeats formation of the insulating resin composition layer, drilling, and circuit formation is becoming mainstream. This build-up technology is roughly classified into a laser method and a photolitho method. The laser method performs laser irradiation to make a hole in the insulating resin composition layer, while the photolitho method uses an insulating resin composition. A photosensitive curing agent (photoinitiator) is used for the layer, a photomask is overlaid, exposed and developed to form holes.

  Several interlayer connection methods aiming at further cost reduction and higher density have been proposed. Among them, a construction method capable of omitting the drilling and conductive layer plating process has attracted attention. In this method, first, a conductive paste is printed on a wiring of a substrate to form bumps, an interlayer connection insulating material in a B-stage state and a metal layer are arranged, and the bumps are penetrated into a molding resin by pressing. It is inserted and electrically connected to the metal layer. This method of penetrating bumps has been published in academic societies and newspapers (see Non-Patent Documents 1 and 2) and is widely recognized in the printed board industry.

  In addition, a material in which a plated wire is embedded in the thickness direction in an elastomer such as silicon rubber has been developed and used as a simple tool for connecting two layers of conductors.

Ohira and others: Proposal of printed wiring board by a new manufacturing method (B2it), Proceedings of the 9th Circuit Packaging Conference, ISSN 0916-0043, 15A-10, PP. 55-56, (March 1995) Takahiro Mori and five others: Application and miniaturization of substrates using bump interlayer connection technology, Proceedings of the 10th Circuit Packaging Conference, ISSN 0916-0043, 15A-09, PP. 79-80, (March 1996)

  However, in the conventional technique, the laser method has a wide selection range of an insulating material, and not only can a hole between adjacent layers be drilled, but also a hole can be drilled to an adjacent layer, but the resin residue evaporated by laser irradiation is removed. For this reason, there is a problem that a desmear process is required and the machining cost increases in proportion to the number of holes.

  On the other hand, in the photolithography method, conventional wiring board manufacturing equipment can be used and drilling can be performed at once, which is advantageous for cost reduction. However, the resolution, heat resistance, circuit and insulating resin composition of the interlayer insulating material are advantageous. There is a problem that it is difficult to achieve compatibility of adhesive strength between layers.

  Moreover, since the bump is formed by conductive paste printing or plating because the bump is inserted, the accuracy depends on the limit of the printing technology, and it is difficult to suppress variation in bump height due to plating. There is a problem.

  Furthermore, it is easy to embed a plated wire in an elastomer such as silicon rubber in the thickness direction, but it is difficult to embed the wire only in an arbitrary place to be connected. There exists a subject that a wire becomes obstructive in the location which does not need to contact.

  In order to solve such problems, the present inventor has devised and invented a connection substrate in which bump groups are embedded. This connection substrate is composed of an insulating resin composition layer and connection conductors, which are bump groups formed so as to penetrate the insulating resin composition layer in the thickness direction at least at locations where the conductor circuit is connected. Is very thin. Therefore, in manufacturing this connection board, the formation of the connecting conductor by etching, etching of the stopper metal layer, roughening treatment, pressing, resin polishing, use of the conveyor device and other tensions when attaching to jigs and tools, etc. In order to prevent occurrence and tearing, it is necessary to improve handling. In particular, resin polishing to expose the connecting conductor is extremely difficult, and until now, the substrate was temporarily fixed using a resist, and polishing was performed. However, since there is anxiety about dimensional stability due to generation of wrinkles and tension application and careful work is required, it has been one of the major factors hindering the improvement of the manufacturing efficiency of the connection board.

  Furthermore, in the method of stacking a plurality of connection substrates manufactured by obtaining the above steps and manufacturing a multilayer wiring board, it is necessary to align the plurality of connection substrates with high accuracy.

  In view of the above, it is an object of the present invention to provide a method for manufacturing a connection board efficiently and a method for manufacturing a multilayer wiring board capable of aligning and stacking a plurality of connection boards with high accuracy. .

  That is, the present invention is characterized by the following.

  (1) The second metal layer side supports a composite metal layer composed of at least the second metal layer and the first metal layer having a different removal condition from one or both surfaces of the support substrate. A step of placing the substrate so as to be on the substrate side and temporarily fixing it by heating and pressing; a step of selectively removing the first metal layer to form a connection conductor; and at least covering the side surface of the connection conductor Alternatively, the step of forming two or more insulating resin composition layers, the step of polishing the insulating resin composition layer so that the connecting conductor is exposed, and the connecting conductor penetrate in the thickness direction of the insulating resin composition layer. And a step of peeling the formed composite metal layer from the supporting base material.

  (2) The composite metal layer is located between the first metal layer, the second metal layer, the first metal layer, and the second metal layer, and the third and different removal conditions are different from those of the third metal layer. (1) The connection conductor is formed by selectively removing the first metal layer and then selectively removing the third metal layer. Method for manufacturing a connection board.

  (3) The method for producing a connection substrate according to (1) or (2), wherein a roughening treatment is performed on a surface of the second metal layer on which the insulating resin composition layer is formed.

  (4) The method further comprising the step of selectively removing the second metal layer and polishing the insulating resin composition layer so that the connection conductor is exposed, thereby forming a conductor circuit (1). )-(3) The manufacturing method of the connection board | substrate in any one.

  (5) After polishing the insulating resin composition layer so that the connection conductor is exposed, a conductor circuit is further provided on the exposed surface of the connection conductor and / or the surface of the conductor circuit formed on the connection conductor surface. The method for manufacturing a connection substrate according to any one of (1) to (4), further including a step of additionally forming.

  (6) The insulating resin composition layer is formed by placing at least one adhesive sheet made of an insulating resin composition so as to cover the connecting conductor, and heating and pressing it. The manufacturing method of the connection board | substrate in any one of said (1)-(5).

  (7) The method for manufacturing a connection substrate according to any one of (1) to (6) above, wherein the insulating resin composition layer contains a thermoplastic resin.

  (8) The connection substrate according to any one of the above (1) to (7), wherein the support base material is one in which the release base material, the adhesive resin, and the release base material are stacked in this order. Manufacturing method.

  (9) The method for producing a connection substrate according to (8), wherein the release substrate has a smaller area than the composite metal layer.

  (10) The method according to (8) or (9), wherein the composite metal layer on which the connecting conductor is formed is peeled from the support base material after cutting the inside from the outer periphery of the release base material. The manufacturing method of the connection board | substrate in any one.

  (11) A step of forming guide holes at predetermined positions of a plurality of connection boards obtained by the manufacturing method according to any one of (1) to (10) above, using a positioning jig, a plurality of sheets Positioning through guide pins formed in the connection board through guide pins, heat-sealing predetermined locations, positioning and fixing multiple connection boards, and positioning jigs for positioning and fixing multiple connection boards A method of manufacturing a multilayer wiring board, comprising the steps of:

  (12) The method for manufacturing a multilayer wiring board according to (11), wherein the guide hole is formed in a part of the connecting conductors.

  (13) An alignment jig includes a pedestal on which guide pins are welded at predetermined positions, and an intermediate plate for position correction, a lower sheet, and an upper sheet on which guide holes for passing the guide pins are formed at predetermined positions. And (11) or (12), wherein a plurality of the connection substrates are sandwiched between the lower sheet and the upper sheet and are aligned. The manufacturing method of the multilayer wiring board as described in 2 ..

  (14) The method for producing a multilayer wiring board according to any one of the above (11) to (13), wherein a liquid crystal polymer is used for the insulating resin composition layer as the outermost layer.

  (15) The method for producing a multilayer wiring board according to any one of (11) to (14) above, further comprising a step of further forming an outer layer circuit after batch lamination by heating and pressurization.

  (16) The method for producing a multilayer wiring board according to any one of (11) to (15), wherein a substrate having a conductor circuit and / or a metal foil is laminated together with the connection substrate.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a multilayer wiring board which can manufacture a connection board | substrate efficiently, and can laminate | stack a connection board of a plurality of connection board | substrates with high precision can be provided.

(A)-(i) is a figure explaining one form of the process in which the connection board | substrate of this invention is manufactured. It is a figure which shows the state which formed the guide hole in the connection conductor of the connection board obtained in FIG. (A)-(c) is sectional drawing and the top view which show the outline of the alignment jig | tool of this invention. (A)-(c) is a figure explaining one form of the process in which a multilayer wiring board is manufactured using the connection board of this invention. (A) And (b) is sectional drawing of the multilayer wiring board of this invention.

  Hereinafter, the present invention will be described in detail.

  In the method for manufacturing a connection substrate of the present invention, first, at least one second metal layer serving as a carrier and a first metal layer having different removal conditions from the second metal layer are formed on one side or both sides of a support base material. The composite metal layer is disposed so that the second metal layer side is the support base material side, and is temporarily fixed by heating and pressing. In FIG. 1 (a), as the support substrate, a support substrate 45 arranged in the order of a release substrate 451, an adhesive resin 452, and a release substrate 451 is used, and composited on both surfaces of the support substrate. As the metal layer, a first metal layer 41, a second metal layer 42, a third metal layer located between the first metal layer 41 and the second metal layer 42 and having a removal condition different from these, FIG. 3 is a diagram in which three composite metal layers 4 each including a metal layer 43 are arranged. FIG. 1B is a diagram showing a state in which the composite metal layer 4 and the support base 45 in FIG.

  As a support base material used for this invention, what was arrange | positioned in order of the mold release base material, adhesive resin, and mold release base material as mentioned above etc. can be used, for example. As the mold release substrate, for example, electrolytic copper foil, rolled copper foil or the like can be used, and the area is made smaller than that of the composite metal layer and the adhesive resin. In addition, as the adhesive resin, a semi-cured and / or cured thermosetting resin, a photocurable resin, a thermoplastic resin, or the like can be used.

  Examples of the thermosetting resin include epoxy resin, bismaleimide triazine resin, polyimide resin, cyanoacrylate resin, phenol resin, unsaturated polyester resin, melamine resin, urea resin, polyisocyanate resin, furan resin, resorcinol resin, xylene. One or more selected from resin, benzoguanamine resin, diallyl phthalate resin, silicone-modified epoxy resin, silicone-modified polyamideimide resin, benzocyclobutene resin, etc., and if necessary, its curing agent, curing accelerator, etc. What mixed was heated and made semi-hardened, or what hardened can be used.

  Examples of the photocurable resin include one or more selected from unsaturated polyester resins, polyester acrylate resins, urethane acrylate resins, silicone acrylate resins, epoxy acrylate resins, and the like, and if necessary, the light. What mixed the initiator, the hardening | curing agent, the hardening accelerator, etc. into the semi-hardened state by exposure or heating, or what hardened can be used. When the photocurable resin is used, the composite metal layer can be temporarily fixed only on one side of the support base material, but can be temporarily fixed to the support base material efficiently.

  Examples of the thermoplastic resin include polycarbonate resin, polysulfone resin, polyetherimide resin, thermoplastic polyimide resin, tetrafluoropolyethylene resin, hexafluoropolypropylene resin, polyetheretherketone resin, vinyl chloride resin, and polyethylene resin. , Polyamideimide resin, polyphenylene sulfide resin, polyoxybenzoate resin, wholly aromatic polyester resin, liquid crystal polymer, etc., and if necessary, the curing agent, curing accelerator, etc. were mixed A semi-cured or heated product can be used.

  These resins may be a resin composition composed of a mixture of different kinds of resins, and may further contain an inorganic filler such as silica or metal oxide as a filler. As the inorganic filler, for example, conductive particles such as nickel, gold and silver, or resin particles plated with these metals may be used. However, when a filler is added, it is important that the rigidity of the resin composition and the adhesion between the resin composition and the composite metal layer be maintained.

  The composite metal layer used in the present invention is a composite metal layer including at least a second metal layer serving as a carrier and a first metal layer having a different removal condition from the second metal layer. It is economically preferable to use a composite metal layer 4 having three layers as shown in a).

  This is because copper is preferably used for the first metal layer for economic reasons, and nickel or an alloy thereof may be used for the second metal layer having a different etching removal condition from the copper. Nickel and its alloys are more expensive than copper. However, when the composite metal layer is composed of two layers, a high mechanical strength is required for the second metal layer that supports the connection conductor formed from the first metal layer. Necessary to use a large amount of expensive metal. In that regard, as the third metal layer, a three-layer composite metal layer obtained by forming a relatively thin expensive metal layer having different etching removal conditions from the first and second metal layers between them, Since the second metal layer can be the same copper as the first metal layer, it is economical and excellent in mechanical strength.

  The thickness of the third metal layer of such a composite metal layer composed of three layers is preferably thin as described above, and is preferably in the range of 0.05 to 5 μm. If the thickness is less than 0.05 μm, the plating film forming the layer of nickel or an alloy thereof is thin enough to be covered with the plating film because it is thin, so-called pits (plating defects) occur, and the first When the metal layer is removed by etching, the second metal layer may be eroded or the etching solution may remain, which may reduce connection reliability. Even if it exceeds 5 μm, there is no problem in the process, but the cost of the material becomes high and it is not economical.

  The first metal layer is preferably formed thicker than the desired insulating layer thickness in order to form a connecting conductor. The degree must be determined according to the amount by which the first metal layer is polished and removed in the step of polishing the insulating resin composition layer, but is preferably in the range of 5 to 100 μm. If the thickness is less than 5 μm, the distance of the conductor circuit to be connected may be reduced and the insulation may be reduced. If the thickness exceeds 100 μm, unnecessary portions of the metal foil may be removed by etching. Processing accuracy is lowered, which is not preferable. More preferably, it is the range of 20-80 micrometers.

  The thickness of the second metal layer is preferably in the range of 5 to 100 μm. When the thickness is less than 5 μm, the mechanical strength is lowered, and the first metal layer is easily bent or bent when selectively removed by etching. When the thickness exceeds 100 μm, the second metal layer is subsequently removed. It is time consuming and not economical. More preferably, it is the range of 10-80 micrometers.

  Next, the first metal layer is selectively removed to form a connecting conductor. When the composite metal layer 4 composed of three layers is used as shown in FIG. 1, the first metal layer 41 is used. After the selective removal, the etching resist is removed, and then the third metal layer 43 is selectively removed. FIG.1 (c) is a figure which shows the state by which the etching resist 44 was formed in the location which forms the conductor for connection of the composite metal layer temporarily fixed to both surfaces of the support base material, FIG.1 (d) FIG. 4 is a diagram showing a state in which a first metal layer 41 and a third metal layer 43 are selectively removed in order and a connection conductor 13 is formed.

  Next, as shown in FIG. 2E, one or more insulating resin composition layers 121 are formed so as to cover at least the side surfaces of the connection conductors 13.

  This insulating resin composition layer is a layer obtained by semi-curing and / or curing a composition containing at least an insulating resin such as a thermosetting resin, a photocurable resin, or a thermoplastic resin.

  Examples of the thermosetting resin include epoxy resin, bismaleimide triazine resin, polyimide resin, cyanoacrylate resin, phenol resin, unsaturated polyester resin, melamine resin, urea resin, polyisocyanate resin, furan resin, resorcinol resin, xylene. One or more selected from resin, benzoguanamine resin, diallyl phthalate resin, silicone-modified epoxy resin, silicone-modified polyamideimide resin, benzocyclobutene resin, and, if necessary, curing agent, curing accelerator, etc. A mixture obtained by heating and making it semi-cured or cured can be used.

  Examples of the photocurable resin include one or more selected from unsaturated polyester resins, polyester acrylate resins, urethane acrylate resins, silicone acrylate resins, epoxy acrylate resins, and the like, and if necessary, the light. What mixed the initiator, the hardening | curing agent, the hardening accelerator, etc. into the semi-hardened state by exposure or heating, or what hardened can be used.

  Examples of the thermoplastic resin include polycarbonate resin, polysulfone resin, polyetherimide resin, thermoplastic polyimide resin, tetrafluoropolyethylene resin, hexafluoropolypropylene resin, polyetheretherketone resin, vinyl chloride resin, and polyethylene resin. One or more selected from polyamideimide resin, polyphenylene sulfide resin, polyoxybenzoate resin, (total) aromatic polyester resin, liquid crystal polymer, and the like can be used. Furthermore, a film obtained by heating, molding and cooling at least one of the above thermoplastic resins can be used.

  For the insulating resin composition layer of the connection board of the present invention, the insulating resin as described above may be used alone or a mixture of different kinds of insulating resins may be used, and an inorganic filler is included as a filler. May be used. The inorganic filler may be a conventionally known one, and is not particularly limited, and examples thereof include conductive particles such as nickel, gold, and silver, silica, metal oxide, or resin particles obtained by metal plating these. Desirably, in order to ensure the insulation of the insulating resin composition, a non-conductive material is preferable.

  In addition, it is preferable that the insulating resin composition used in the present invention contains a thermoplastic resin because it can save the trouble of applying the resin to the substrate surface again when multilayered. More preferably, it is an insulating resin composition containing a liquid crystal polymer which is a thermoplastic resin. When an insulating resin composition containing a liquid crystal polymer is used, its linear expansion coefficient can be brought close to the linear expansion coefficient of copper, which is effective for laminating the insulating resin composition at the same time as connecting the connection conductors. is there. The liquid crystal polymer used in the present invention preferably has a phase transition temperature from a smectic phase to a nematic phase of 180 ° C. or higher, more preferably 280 ° C. or higher because it can withstand the reflow processing temperature of leadless solder. Specifically, Xydar SRT-300, SRT-500, FSR-315, RC-210, FC-110, FC-120, FC-130 (above, Nippon Petrochemical Co., Ltd., trade name), Econol E2000 (Commercial name, manufactured by Sumitomo Chemical Co., Ltd.) Series, Econol E6000 (Product name, manufactured by Sumitomo Chemical Co., Ltd.) Series, Vectra A950, Vectra A130, Vectra C130, Vectra A230, Vectra A410 (above, Polyplastics (Trade name), EPE-240G30 (trade name, manufactured by Mitsubishi Kasei Co., Ltd.), Rod Run LC-5000H (trade name, manufactured by Unitika Ltd.), Novacurate E322G30, E335G30, EPE-240G30 (and above) , Manufactured by Mitsubishi Chemical Corporation, trade name), BIAC (Japan Gore-Tex Co., Ltd.) Product name).

  In addition, as a method of forming the insulating resin composition layer, the insulating resin composition can be formed by directly applying the insulating resin composition to the substrate surface on which the connection conductor is formed, but a plastic film such as a polyethylene terephthalate film or copper Foil, metal foil such as aluminum foil is used as a carrier, the insulating resin composition is applied to the surface, the adhesive sheet made into a dry film by heating and drying is cut to the required size, and a conductor for connection is formed It can also be formed by laminating or pressing the substrate.

  Moreover, it is preferable that the thickness of the insulating resin composition layer is in the range of 1 to 100 μm. If the thickness is less than 1 μm, it is difficult to form the insulating resin composition with a uniform thickness to such an extent that the adhesive strength does not decrease, and if it exceeds 100 μm, it becomes difficult to expose the connecting conductor. More preferably, it is the range of 3-70 micrometers.

  Moreover, since it is not preferable in terms of connection reliability that bubbles are entrained in the insulating resin composition layer covering the connection conductor, it is more preferable that bubbles do not exist as much as possible.

  Further, the insulating resin composition layer may be one layer or two or more layers, but forming two or more layers alleviates thermal stress generated on the substrate surface in the process of pressing, polishing, etc. This is preferable because warpage of the film can be reduced. In addition, when forming two or more insulating resin composition layers, not only the type of insulating resin composition to be used, but also the hardness of the resin after molding, the thickness of the resin after molding, the difference in molecular orientation, the filler It is preferable to distinguish them depending on the presence or absence of the filler, the type or content of the filler, the average particle diameter of the filler, the particle shape of the filler, the specific gravity of the filler, and the like. In addition, when a liquid crystal polymer is used to make the insulating resin composition layer a multi-layer structure as described above, the liquid crystal polymer can be formed by utilizing the property that it easily forms a multi-layer structure based on molecular orientation when molded. It can be used alone to form a multilayer structure.

  In addition, it is preferable to roughen the exposed surface of the second metal layer before forming the insulating resin composition layer in order to improve the adhesion strength with the insulating resin composition.

  The insulating resin composition layer is preferably formed using an adhesive sheet made of an insulating resin composition, and a plurality of different or similar sheets may be used in a stacked manner.

  Next, as shown in FIG. 1 (f), after polishing the insulating resin composition layer 121 so that the connecting conductor 13 is exposed, the connecting conductor 13 penetrates in the thickness direction of the insulating resin composition layer 121. The connection substrate 11 as shown in FIG. 1G can be obtained by peeling the composite metal layer 46 thus formed from the support base material. Furthermore, by selectively removing the second metal layer 42, a connection substrate having a conductor circuit 103 as shown in FIG.

  In the present invention, it is important that the connecting conductor is formed so as to penetrate the insulating resin composition layer in the thickness direction at least at a location where the conductor circuit is connected. Among the conventional techniques, in the connection tool in which the wire is embedded in the elastomer, since the wire is embedded at a constant interval, if the position of the circuit conductor of the two layers to be connected is slightly shifted, the connection cannot be performed, or There is a possibility that a part that is not planned is connected, and it is difficult to connect a fine conductor circuit with high accuracy. On the other hand, the present invention does not form a conductor in a part that is not planned to be connected. A fine circuit can be formed well.

  Further, the surface of the connecting conductor exposed by polishing the insulating resin composition layer and / or the surface of the conductor circuit formed on the surface of the connecting conductor is further overlaid with metal foil, metal plating, etching, etc. By performing this process, a conductor circuit can be additionally formed or a metal film can be applied. FIG. 1I is a diagram in which a metal film is formed on the connection conductor surface 13 and the conductor circuit surface 103 of the connection substrate 11 in FIG. For example, the metal film may be formed by applying electroless copper plating after applying palladium, vacuum film-forming methods such as copper sputtering or chromium base copper sputtering, metal paste printing such as silver paste, displacement gold plating, nickel / gold electrolysis or no It can be formed by plating such as electrolytic plating, electrolysis of nickel / palladium / gold plating or electroless plating, or electroless plating of tin or a tin alloy.

  Further, a protruding conductor called a bump may be formed on a conductor circuit connected to the connection conductor. In order to form the bumps on the connection substrate of the present invention, portions other than the relatively thick conductor protrusions are half-etched in the thickness direction to form protrusions, and the conductor circuit portions and protrusions further thinned. It can be formed by etching away other parts while leaving In another method, after the circuit is formed, only the connection terminal portion is thickened by plating.

  Further, the exposed state of the connecting conductor may protrude from the surface of the insulating resin composition layer, or may enter the inside from the surface of the insulating resin composition layer. The former can be projected by adding a new metal layer after polishing flatly as described later. The latter is possible, for example, by etching back with an etching solution.

  The thickness of the connecting conductor is preferably in the range of 5 to 100 μm. When the thickness is less than 5 μm, the interlayer distance of the conductor circuit to be connected may be reduced and the insulation may be lowered. When the thickness exceeds 100 μm, unnecessary portions of the metal foil are removed by etching. This is not preferable because the processing accuracy is reduced. More preferably, it is the range of 20-80 micrometers.

  In addition, since the composite metal layer is not bonded to the support substrate, by cutting so that all of the support base material surface in contact with the second metal layer becomes the release base without cutting, The connection substrate can be easily detached from the support substrate, and the connection substrate can be manufactured very efficiently.

  Next, the manufacturing method of the multilayer wiring board of this invention is demonstrated.

  FIG. 2 is a view showing a state in which guide holes are formed in some of the connection conductors of the connection substrate of FIG.

  This guide hole is used for positioning by passing a guide pin when the connection substrate is multi-layered using a jig described later. Of course, the guide hole may be provided in addition to the connection conductor. However, by forming the guide hole in the connection conductor as described above, the guide hole is reinforced and the alignment accuracy can be improved, which is preferable. When the guide hole is formed in the connection conductor, the diameter of the connection conductor must be larger than the hole diameter of the guide hole, and the formation thereof is not particularly limited, but is provided in contact with the connection conductor. It is preferable to use an NC drill that can image-process the land portion of the wiring layer and drill a hole at an accurate position. If there are many guide holes, it is necessary to first form two guide holes, place a guide pin there, then place an NC drill on the basis of this and form other guide holes. Position accuracy can be improved, which is preferable.

  Next, as shown in FIG. 4A, a plurality of connection boards are sandwiched using an alignment jig in which guide holes are accurately provided.

  As shown in FIG. 3A, the alignment jig used in the present invention has a pedestal 31 on which guide pins 311 are welded at predetermined positions, and a position correction having guide holes through which the guide pins 311 pass. It comprises at least an intermediate plate 32, a lower receiving sheet 33, an upper placing sheet 34, and a pressing jig 35, and performs positioning by sandwiching a plurality of connection boards between the lower receiving sheet 33 and the upper placing sheet 34. is there. Here, the intermediate plate for position correction is used to correct the positional accuracy error caused by the guide pin fluctuation or repeated use, and the upper sheet and the holding jig are shown in FIGS. As shown to (c), it has a notch in each side of a rectangle.

  Next, in the state shown in FIG. 4A with the plurality of connection substrates sandwiched therebetween, the plurality of connection substrates are heat-sealed using a soldering iron or the like at the notch formed in the upper sheet and the holding jig. After that (FIG. 4B), by removing this from the alignment jig, it is possible to obtain a plurality of connection boards positioned and fixed by the heat fusion part 444 as shown in FIG. 4C. it can. Furthermore, a release film such as a polyimide film is placed on both surfaces of a plurality of connection substrates that are positioned and fixed, and after heating and pressurizing and laminating them at once, the release film is peeled off, whereby FIG. A multilayer wiring board as shown in a) can be obtained.

  In addition, when batch stacking, for example, as shown in FIG. 5 (b), there may be a case where a connecting structure of each layer has a crank-like structure that is not on an extension line passing through the connection board. The conductor circuit may be deformed and the stability of the connection resistance may be impaired. Therefore, it is preferable to use an insulating resin composition having a high elastic modulus for the insulating resin composition layer of the connection substrate that is inside the multilayer wiring board. When the insulating resin composition layer is composed of two or more layers, it is desirable that the resin layer in contact with the conductor circuit has a high elastic modulus. The specific value of the elastic modulus is preferably 0.0001 GPa or more, more preferably 0.001 GPa or more, and particularly preferably 0.01 GPa or more at the temperature during heating. The dynamic elastic modulus of the insulating resin composition can be measured by using ARES (parallel plate, temperature rising at a frequency of 1 Hz, 5 ° C./min.) Manufactured by Rheometric.

  In addition, a multilayer wiring board of the present invention may be obtained by laminating a substrate having a conductor circuit and / or a metal foil together with the connection substrate of the present invention. Furthermore, an outer layer circuit may be formed on the outermost layer of the multilayer wiring board by plating or etching after the lamination.

  Moreover, it is preferable to use the insulating resin composition containing a thermoplastic resin, and it is more preferable that the insulating resin composition layer used as the outermost layer of a multilayer wiring board contains a liquid crystal polymer.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to this.

Example 1
As shown in FIG. 1A, the first metal layer 41 is copper having a thickness of 70 μm, the third metal layer 43 is nickel having a thickness of 0.2 μm, and the second metal layer 42 is thick. A composite metal layer 4 made of 18 μm thick copper, with the first metal layer 41 on the outside, and an electrolytic copper foil YGP-18R (product name) 451 as a mold release substrate, Three pieces of liquid crystal polymer BIAC film 100 μm (trade name, manufactured by Japan Gore-Tex Corporation) 452 are arranged in the order of electrolytic copper foil YGP-18R (trade name, manufactured by Nippon Electrolytic Co., Ltd.) 451 as a release substrate. At this time, the electrolytic copper foil 451 had a smooth surface outside. Moreover, as shown in the figure, the electrolytic copper foil 451 is made smaller in size than the composite foil. A polyimide film (manufactured by Ube Industries, not shown) on both sides of such a structure is temporarily fixed by applying a temperature of 333 ° C. and a pressure of 4 MPa for 5 minutes so as to include at least these structures, and heating and pressurizing. After that, the polyimide film was peeled off by hand to obtain a structure as shown in FIG.

Next, as shown in FIG. 1C, an etching resist 44 was formed on the surface of the first metal layer 41 in the shape of the connection conductor 13. As this etching resist 44, resist NCP225 or NIT225 (product name, manufactured by Nichigo Morton Co., Ltd.) is used, and the resist is laminated at a roll temperature of 110 ° C. and a roll speed of 0.6 m / min. The film was baked under an exposure condition of / cm ² , developed with a sodium carbonate solution, and post-exposed at 200 mJ / cm ² in order to ensure adhesion of the resist.

  Next, an alkaline etching A process solution (trade name, manufactured by Meltex Co., Ltd.), which is an etching solution that does not erode nickel, is sprayed and sprayed to selectively remove the first metal layer 41, thereby connecting conductors 13. Formed. Thereafter, the etching resist 44 was stripped and removed with a sodium hydroxide solution. Next, the third metal layer 43 is removed by etching using Melstrip N950 (trade name, manufactured by Meltex Co.), which is a nickel etching solution, and the surface treatment liquid CPE900 (manufactured by Mitsubishi Gas Chemical Company) is sprayed. Then, the exposed copper surface was roughened to obtain a structure in which the composite metal layer 46 on which the connection conductor 13 shown in FIG. 1D was formed was temporarily fixed on both surfaces.

  Next, a 75 μm-thick liquid crystal polymer BIAC sheet (manufactured by Japan Gore-Tex) as an insulating resin composition is placed on both sides of the composite metal layer 46, and a polyimide film (manufactured by Ube Industries) is placed on the liquid crystal polymer sheet. Is applied so that a temperature of 333 ° C. and a pressure of 4 MPa are applied from both sides for 5 minutes to heat and pressurize, and then the polyimide film is peeled by hand, as shown in FIG. A structure in which the insulating resin composition layer 121 was formed was obtained.

  Thereafter, the structure shown in FIG. 1 (e) was polished by passing through both surfaces at once by adjusting the load and the rotational speed of the gap between the rotating polishing rolls 47 as shown in FIG. 1 (f). Polishing was performed under conditions of thickness reduction of 4 μm per pass, and the tip of the connection conductor 13 was exposed on the whole surface in 4 to 5 passes. Therefore, the polishing amount was 20 μm on each side. After polishing, the connection substrate was detached from the interface of the support substrate by cutting the inner side from the electrolytic copper foil which is the release base material in the configuration. Thereby, as shown in FIG.1 (g), the connection board | substrate which conducted with the metal layer and incorporated the connection conductor was able to be obtained. Thereafter, the second metal layer 42 was selectively etched to obtain a connection substrate on which a conductor circuit 103 as shown in FIG. 1 (h) was further formed. Furthermore, a metal coating 21 is formed in the order of electroless nickel, electroless palladium, and electroless gold plating on the surface of the connection conductor 13 and the surface of the conductor circuit 103 of the connection substrate of FIG. A connection substrate shown in (i) was obtained.

Example 2
As shown in FIG. 2, guide holes 22 having a diameter of 3.0 mm were formed in a part of the connection conductors of the connection board shown in FIG. 1 (i) obtained in Example 1 using an NC drill. Here, two guide holes were first formed, a guide pin was set up on this, an NC drill was placed on the basis of this, and other guide holes were formed.

  Next, as shown in FIG. 4A, the guide pin 311 welded to the pedestal 31 is connected to the correction intermediate plate 32, the lower receiving sheet 33, the four connection boards obtained above, and the upper sheet 34. Then, the holding jig 35 was stacked in the order of the holding jig 35 through the guide holes formed therein. Here, both the lower sheet 33 and the upper sheet 34 are Teflon (registered trademark) substrates, and have a hole slightly larger than 0.3 mm. Further, while the lower receiving sheet 33 is a square, the upper sheet 34 and the holding jig have a notch as shown in FIGS. 3B and 3C.

  As shown in FIG. 4 (b), the tip of the soldering iron heated to 265 ° C. in the cutout portions of the upper sheet 34 and the holding jig 35 where the connection substrate is exposed is placed in several places for several seconds. They were pressed and fixed between the connection substrates by thermal melting.

  Thereafter, as shown in FIG. 4 (c), the holding jig 35 is removed, the upper part is lifted from the receiving sheet 33, the position is adjusted with high accuracy from the positioning jig, and a predetermined portion is thermally melted. The structure of the connection substrate fixed by the positioning was removed. Next, a polyimide film (manufactured by Ube Industries) is placed on both sides of the structure so as to cover the insulating resin composition layer, and at least these structures are included so that a temperature of 333 ° C. and 4 MPa are provided from both sides. The pressure was applied for 5 minutes, and heating and pressurization were performed to integrate the layers, and then the polyimide film was peeled by hand to obtain a four-layer multilayer wiring board shown in FIG. Further, it was also possible to produce a conductor in which the connecting conductors are not connected on the same straight line but are conductively connected in a crank shape as shown in FIG.

  Furthermore, the conduction | electrical_connection connection by alloying of gold-gold of the obtained multilayer wiring board has been confirmed. Further, even when electroless tin plating (replacement type or reduction type) was used for surface plating on the connection substrate, a multilayer wiring board could be similarly produced. In addition, electroless nickel, electroless palladium, and electroless gold plating were used for the surface plating of the outermost connection board, and electroless tin plating (substitution type or reduction type) was used for the surface plating of the inner connection board. A multilayer wiring board can be produced in the same manner even when a connection substrate having a different surface plating type is used, and conduction connection by alloying of gold-tin or tin-tin can be confirmed at the connection portion. Moreover, the wiring of the outermost layer was transferred to the insulating resin composition layer, and a smooth surface without a step was confirmed on the surface of the substrate. The present invention is a specific structure that has been specifically implemented and confirmed. Thereby, peeling strength improvement with the base material of a fine circuit can be anticipated.

11: Connection substrate 121: Insulating resin composition layer 13: Connection conductor 101, 102: Metal foil 103: Conductor circuit 21: Metal layer 22: Guide hole 31: Base 311: Guide pin 32: Correction intermediate plate 33: Bottom Receiving sheet 34: Overlay sheet 35: Holding jig 4: Composite metal foil 41: First metal layer 42: Second metal layer 43: Third metal layer 44: Etching resist 444: Thermal fusion part 45: Support base material 451: Release base material 452: Adhesive resin 46: Composite metal foil 47 on which the connecting conductor 13 is formed: Polishing roll

Claims (6)

A first metal layer, a second metal layer, a third metal layer that is located in the middle of the first metal layer and the second metal layer on one side or both sides of the support substrate, and has different removal conditions. A step of disposing a composite metal layer composed of the metal layer in such a manner that the second metal layer side is the support base material side, and heating and pressing to temporarily fix the composite metal layer,
Forming the connection conductor by selectively removing the third metal layer after selectively removing the first metal layer;
A step of roughening the surface of the second metal layer on which the insulating resin composition layer is formed;
Forming one or more of the insulating resin composition layers so as to cover at least the side surface of the connecting conductor;
Polishing the insulating resin composition layer so that the connection conductor is exposed;
Peeling the composite metal layer formed so that the connecting conductor penetrates in the thickness direction of the insulating resin composition layer from the support substrate; and
A method of manufacturing a connection substrate, comprising: a step of selectively removing a second metal layer after polishing and peeling the insulating resin composition layer so that the connection conductor is exposed, and forming a conductor circuit. There,
The supporting base material is an electrolytic copper foil as a release base material, and the electrolytic copper foil, the adhesive resin, and the electrolytic copper foil are arranged in the order of the smooth surface of the electrolytic copper foil, and the electrolysis The copper foil has a smaller area than the composite metal layer and the adhesive resin, and
The step of peeling the composite metal layer from the support substrate is performed by cutting the inner side of the outer periphery of the electrolytic copper foil as a cut surface, and then peeling the composite metal layer on which the connection conductor is formed from the support substrate. A method for manufacturing a connection board, comprising:   The method for manufacturing a connection substrate according to claim 1, wherein a roughening treatment is performed on a surface of the second metal layer on which the insulating resin composition layer is formed.   The method further comprises the step of selectively removing the second metal layer and forming a conductor circuit after polishing the insulating resin composition layer so that the connection conductor is exposed. The manufacturing method of the connection board | substrate of Claim 2.   After polishing the insulating resin composition layer so that the connection conductor is exposed, a conductor circuit is further provided on the exposed surface of the connection conductor and / or the surface of the conductor circuit formed on the connection conductor surface. The method for manufacturing a connection board according to claim 1, further comprising a step of additionally forming.   The at least one adhesive sheet made of an insulating resin composition is placed so as to cover the connection conductor, and the insulating resin composition layer is formed by heating and pressing the adhesive sheet. Item 5. A method for producing a connection board according to any one of Items 1 to 4.   The method for manufacturing a connection substrate according to claim 1, wherein the insulating resin composition layer includes a thermoplastic resin.

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