JP2005158974A - Method for manufacturing multi-layer printed wiring board and sheet material for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a multi-layer printed wiring board by which a via hole can be made in an optional layer while a sheet material with conductor wiring is used to reduce the frequency of pressing, and to provide such a multi-layer printed wiring board that is superior in interlayer adhesion and conduction reliability. <P>SOLUTION: A metallic layer 1 is formed on one surface of a hard insulating layer 2, an adhesive layer 4 and a protection film 5 are stacked on the other surface thereof, and conductor wiring 3 is formed by patterning of the metallic film 1. A hole 6 is made so as to penetrate the protection film 5, the adhesive layer 4 and the hard insulating layer 2. The hole 6 is filled with a conductive material 7 and a cover film 9 is stacked on the outer layer of the protection film 5. Then, the surface of the conductor wiring 3 is roughened, and the cover film 9 and the protection film 5 are peeled off to form a board for multilayer. A plurality of boards including the board for multilayer are piled up and are formed as one body. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a multilayer printed wiring board effective for manufacturing a multilayer printed wiring board having an interstitial via hole structure, and a sheet material for manufacturing a multilayer printed wiring board used for manufacturing the multilayer printed wiring board. Is.

  A method for manufacturing a multilayer printed wiring board having an interstitial via hole (IVH) has been studied for a long time, and there has been progress in laser processing technology and paste printing technology. Construction methods that can reduce the number of times have been proposed. In particular, in recent years, many proposals have been made for a multilayer printed wiring board that can form IVH in an arbitrary layer while reducing the number of presses using a sheet material on which conductor wiring 3 is formed (Patent Documents 1 and 2). reference).

  The construction method disclosed in Patent Document 2 will be briefly described. First, an insulating hard substrate having a metal film 1 attached to one surface of a hard insulating layer 2 as shown in FIG. Next, the metal film 1 is etched to form a conductor wiring 3 as shown in FIG. 3B, and the surface of the conductor wiring 3 adheres to the insulating layer during subsequent press molding. A roughening treatment is performed to improve the surface roughness. Next, as shown in FIG. 3C, an adhesive layer 4 is formed on the surface of the hard insulating layer 2 opposite to the conductor wiring 3, and a protective film 5 made of film, paper, or the like is further formed on the outer surface. It is formed by stacking. Next, as shown in FIG. 3 (d), a hole 6 that penetrates the protective film 5, the adhesive layer 4, and the insulating hard substrate in the thickness direction and reaches the conductor wiring 3 is formed. Next, as shown in FIG. 3E, the hole 6 is filled with a conductive material 7 such as a conductive paste to produce a single-sided wiring board.

Similarly, a plurality of single-sided wiring boards as shown in FIG. Next, after peeling off the protective film 5, they are superposed and integrated by heating and pressurizing using a hot press to produce a multilayer printed wiring board. At this time, the conductor wiring of the multilayer printed wiring board was filled with the conductor wiring 3 and the insulating layer of the multilayer printed wiring board was filled with the hard insulating layer 2 and the adhesive layer 4 in the hole 6. Via holes (interstitial via holes) of the multilayer printed wiring board are respectively formed by the conductive material 7.
JP-A-9-36551 Japanese Patent Laid-Open No. 2001-164841

  In the conventional method shown above, first, the conductor wiring 3 is used so that the conductive material 7 such as the adhesive layer 4 and the conductive paste is not deteriorated by being exposed to the treatment liquid used for roughening the conductor wiring 3. After the surface roughening is performed, the adhesive layer 4 is formed, the holes 6 are formed, and the conductive material 7 is filled.

  However, in this conventional method, in order to improve the adhesiveness between the conductor wiring 3 and the resin, the surface of the conductor wiring 3 is roughened and the heat pressing is performed before the formation of the insulating layer and the hole 6. And the process of filling the hole 6 with a conductive paste by a printing method, while the substrate is flattened during laser drilling or paste printing by printing. When the surface of the conductor wiring 3 is placed on the table, the roughened surface of the conductor wiring 3 is crushed, and the surface of the conductor wiring 3 roughened at the corner becomes smooth, or the surface of the conductor wiring 3 is damaged by contact. When trouble occurs, sufficient adhesion with the insulating layer cannot be obtained, causing delamination after pressing, and when the conductor wiring 3 and the via hole are joined. Enough between the via hole There is a possibility that through reliability may become impossible to obtain.

  The present invention has been made in view of the above points, and an interstitial via hole (IVH) can be formed in an arbitrary layer while reducing the number of presses using a sheet material on which a conductor wiring is formed. And a method for producing a multilayer printed wiring board capable of providing high adhesion between the layers and ensuring high conduction reliability between the conductor wiring and the via hole, and a multilayer used in the production of the multilayer printed wiring board It aims at providing the sheet | seat material for printed wiring board manufacture.

  As a result of intensive studies to achieve the above-described object, the present inventors have completed an invention having the following contents.

That is, the manufacturing method of the multilayer printed wiring board 18 according to the present invention is as follows.
(1) The metal film 1 is laminated and formed on one surface of the hard insulating layer 2, the adhesive layer 4 that can be temporarily melted by heating is formed on the other surface, and the protective film 5 is laminated on the outer surface thereof, and the metal Forming a conductor wiring 3 by patterning the film 1;
(2) A step of forming a hole 6 through which the conductor wiring 3 is exposed at the bottom while penetrating the protective film 5, penetrating the protective film 5, the adhesive layer 4 and the hard insulating layer 2 (3) ) Filling the hole 6 with a conductive material 7;
(4) a step of laminating a cover film 9 so as to close the hole 6 on the outer layer of the protective film 5;
(5) Roughening the surface of the conductor wiring 3;
(6) The process of peeling the said cover film 9,
(7) peeling the protective film 5 and causing the conductive material 7 to protrude from the adhesive layer 4;
(8) A step of laminating and integrally forming a plurality of substrates 15 including the multilayer substrate 16 produced through the steps (1) to (7).
In this way, the roughening treatment of the conductor wiring 3 is performed after the formation of the holes 6 for forming the via holes 12 and the filling of the conductive material 7, and then the adhesive layer. 4 is protected by the protective film 5 and the conductive material 7 is protected by the protective film 5 and the cover film 9, and after the roughening of the conductor wiring 3, the multilayer substrate is quickly formed. 16 can be integrally formed with another substrate 15.

  Moreover, it is preferable to laminate | stack the cover film 9 in the said process (4) by roll lamination. Thereby, it can be made to adhere | attach uniformly, without lifting the cover film 9, and the chemical | medical solution penetration | invasion by a subsequent process can be prevented.

  Moreover, the roughening process of the conductor wiring 3 in the said process (5) is a process of providing an unevenness | corrugation in the surface of the conductor wiring 3, and the chemical | medical solution process by which the process liquid 10 is spread only from the process surface side of the conductor wiring 3 It is preferable that Thereby, it is possible to prevent the processing liquid 10 from entering the hole 6 from the gap between the cover film 9 and the protective film 5 and the conductive material 7 is exposed to the processing liquid 10. Can be reliably prevented, and the protection of the conductive material 7 in the hole 6 can be sufficiently achieved.

Moreover, the sheet material 14 for producing a multilayer printed wiring board according to the present invention includes:
(1) The metal film 1 is laminated and formed on one surface of the hard insulating layer 2, the adhesive layer 4 that can be temporarily melted by heating is formed on the other surface, and the protective film 5 is laminated on the outer surface thereof, and the metal Forming a conductor wiring 3 by patterning the film 1;
(2) A step of forming a hole 6 through which the conductor wiring 3 is exposed at the bottom while penetrating the protective film 5, penetrating the protective film 5, the adhesive layer 4 and the hard insulating layer 2 (3) ) Filling the hole 6 with a conductive material 7;
(4) A step of laminating a cover film 9 on the outer layer of the protective film 5 so as to close the hole 6;
It has been manufactured by sequentially passing through the above. When the conductor wiring 3 of the sheet material 14 for manufacturing the multilayer printed wiring board is subjected to a roughening treatment, the adhesive layer 4 is formed after the holes 6 for forming the via holes 12 and the conductive material 7 are filled. The conductor wiring 3 can be roughened with the protective film 5 and the conductive material 7 protected by the protective film 5 and the cover film 9, and the sheet material for manufacturing the multilayer printed wiring board can be used. The protective film 5 and the cover film 9 are peeled from 14, and the obtained multilayer substrate 16 can be used for the production of the multilayer printed wiring board 18.

  According to the present invention, since the multilayer substrate 16 can be integrally formed with the other substrate 15 immediately after the roughening of the conductor wiring 3 as described above, the conductor wiring 3 of the multilayer substrate 16 is formed. When the substrate is placed on the table of a flat processing machine, for example, when the substrate is placed on a flat processing machine table during laser drilling or printing paste printing, the surface of the conductor wiring 3 is crushed. The multilayer printed wiring board 18 can be manufactured by laminating and integrating before the roughened surface of the conductor wiring 3 becomes smooth, and has excellent interlayer adhesion and between the conductor wiring 3 and the via hole 12. It is possible to provide excellent conduction reliability.

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

  First, the sheet material 14 for manufacturing a multilayer printed wiring board will be described.

  The sheet material 14 for producing a multilayer printed wiring board is obtained by laminating a conductor wiring 3, a hard insulating layer 2, a protective film 5, and a cover film 9 in this order. The multilayer printed wiring board manufacturing sheet material 14 is provided with one or a plurality of holes 6 penetrating the hard insulating layer 2 and the protective film 5 at predetermined positions. One end of the hole 6 is closed with a cover film 9 and the other end is closed with a conductor wiring 3. The hole 6 is filled with a conductive material 7 (FIG. 1E).

  In producing the sheet material 14 for manufacturing a multilayer printed wiring board, first, in the first step, the metal film 1 is laminated on one surface of the hard insulating layer 2 and can be temporarily melted by heating on the other surface. The sheet | seat material 13 which laminated | stacked the protective film 5 on the outer surface while forming the adhesive bond layer 4 is produced (FIG. 1 (a)). Further, the metal film 1 of the sheet material 13 is patterned to form a conductor wiring 3 (FIG. 1B).

  The hard insulating layer 2 can be formed of an appropriate hard insulating material. For example, the hard insulating layer 2 can be formed by curing and molding a thermosetting resin. In this case, the curing reaction of the thermosetting resin constituting the hard insulating layer 2 is completed. The hard insulating layer 2 is preferably contained in a base material in terms of dimensional stability. As the thermosetting resin for forming the hard insulating layer 2, an appropriate one for forming a wiring board can be used, and examples thereof include an epoxy resin, a bismaleimide triazine resin, and a fluororesin. Moreover, when using a base material, it is preferable from a heat resistant point to use woven fabrics, nonwoven fabrics, etc., such as glass fiber and an organic fiber, for example.

  The metal film 1 is made of an appropriate material, but is preferably formed using a metal foil such as a copper foil.

  In laminating the hard insulating layer 2 and the metal film 1, an appropriate method can be used, but the same method as the manufacturing process of a normal metal foil-clad laminate can be employed. That is, for example, a base material such as the above is impregnated with a resin varnish containing the thermosetting resin as described above, and heat-dried to form a B-stage to produce a prepreg, and the required number of prepregs and copper foil, The metal foil is superposed and subjected to heat and pressure treatment, whereby the resin component of the prepreg is heated and cured to form the hard insulating layer 2 and the metal film 1 laminated on the hard insulating layer 2 is formed. Is. At this time, the metal film 1 is provided only on one side of the hard insulating layer 2, but after the metal film 1 is provided on both sides of the hard insulating layer 2, the metal film 1 on one side may be removed.

  The hard insulating layer 2 and the metal film 1 can be formed to have an appropriate thickness. The thickness of the hard insulating layer 2 is 0.02 to 1.0 mm, and the thickness of the metal film 1 is 0.005 to 0.070 mm. It is preferable to form in the range.

  When laminating the hard insulating layer 2 and the metal film 1 as described above, when the hard insulating layer 2 is formed with a base material, the base material is particularly a glass woven fabric or an organic woven fabric, and is opened. It is preferable to use one that has been subjected to a fiber treatment. In this case, the dimensional stability of the hard insulating layer 2 is improved and the impregnation of the resin is improved by opening the fiber to prevent unfilling, and the insulation reliability between the via holes 12 formed in the multilayer printed wiring board 18 is improved. Can be improved.

  The adhesive layer 4 is formed on the outer surface of the hard insulating layer 2 formed as described above opposite to the metal film 1. For example, an adhesive containing a thermosetting resin is applied to the outer surface of the hard insulating layer 2 by a roll coater, curtain coater, spray coater, screen printing, or the like, and is precured, or such an adhesive is formed into a sheet. The adhesive sheet formed into a laminate can be obtained by laminating the hard insulating layer 2 using a hot roll or the like. Further, the adhesive layer 4 is formed so as to be capable of being temporarily melted by heating and to be cured by heating thereafter. Specifically, a thermosetting resin composition for forming a laminate such as an epoxy resin composition is used as an adhesive containing a thermosetting resin, and a coating formed with this thermosetting resin composition is used. The adhesive layer 4 can be formed by forming a B-stage by heating and drying the film or the adhesive sheet. Although the thickness of this adhesive bond layer 4 is adjusted suitably, it is preferable to set it as the range of 10-50 micrometers.

  The protective film 5 is not particularly limited, but preferably has chemical resistance against chemicals used when forming the conductor wiring 3 described later, such as an aqueous copper chloride solution or an aqueous sodium hydroxide solution, specifically polyethylene. A terephthalate film or the like can be used.

  Moreover, it is preferable that the protective film 5 has moderate adhesiveness with the adhesive layer 4. That is, at the time of forming the conductor wiring 3 to be described later or roughening treatment, the protective film 5 is not peeled off from the adhesive layer 4 so that the adhesive layer 4 is exposed in the chemical used at the time of forming the conductor wiring 3. It is preferable to have appropriate adhesion that prevents the drug from being contaminated, and can be easily peeled off when the protective film 5 is peeled off from the adhesive layer 4. is there. For this purpose, it is preferable that the surface roughness Rz (ten-point average roughness; JIS B 0601) on the side of the protective film 5 attached to the adhesive layer 4 is in the range of 0.01 to 5 μm.

  Moreover, since the thickness of the protective film 5 corresponds to the protruding dimension of the conductive bump 8 as will be described later, it is appropriately set according to the desired protruding dimension of the conductive bump 8. The protruding dimension of the bump 8 is preferably 5 to 100 μm, and the thickness dimension of the protective film 5 is also preferably in the range of 5 to 100 μm.

  By conducting a patterning process on the metal film 1 provided on one surface of the sheet material 13 formed in this way, the conductor wiring 3 is formed. The patterning process can be performed by an appropriate method. For example, a dry film made of a photosensitive resin composition is laminated on the surface of the metal film 1 and attached, an etching resist is formed through an exposure / development process, and then etching is performed. The conductor wiring 3 can be formed as shown in FIG. 1B by treating with a liquid and peeling off the remaining etching resist.

  Next, as shown in FIG. 1 (c), holes reaching the conductor wiring 3 through the protective film 5, the adhesive layer 4, and the hard insulating layer 2 from the protective film 5 side with respect to the sheet material 13. 6 is formed. At this time, the conductor wiring 3 is exposed at the bottom surface of the hole 6 so that one end of the hole 6 is opened and the other end is closed by the conductor wiring 3. The hole 6 can be formed by using an appropriate method, for example, by irradiation with a carbon dioxide laser. In addition, after the formation of the holes 6, it is preferable to remove the resin residue by performing plasma treatment or UV irradiation on the inner surface of the holes 6. Moreover, although the opening diameter of the hole 6 can be made into a suitable dimension, Preferably it is 30-500 micrometers, More preferably, it is set as the range of 50-200 micrometers.

  Next, as shown in FIG. 1 (d), the hole 6 is filled with a conductive material 7. As the conductive material 7, it is possible to use a conductive paste or the like generally used for forming a via hole in a wiring board. For example, a conductive powder such as silver powder or copper powder is used as a thermosetting resin composition. What was mixed in the thing is used. The conductive material 7 can be filled in the holes 6 by printing application such as screen printing. At this time, the protective film 5 protects the conductive material 7 from adhering to the outer surface of the adhesive layer 4.

  Next, as shown in FIG. 1E, a cover film 9 is laminated on the outer layer of the protective film 5 by lamination or the like. The cover film 9 is formed so as to close at least the hole 6 filled with the conductive material 7 described above, and may be provided on the entire surface of the protective film 5. As the cover film 9, an appropriate material can be used. For example, a film made of a thermoplastic resin such as polyethylene terephthalate, polyester, polyethylene, or polyphenylene sulfide can be used.

  The cover film 9 is formed with the protective film 5 to such an extent that the processing liquid 10 such as a soft etching liquid during the roughening process described later can be prevented from entering between the cover film 9 and the protective film 5. It is preferable to have adhesiveness between them. Further, it is preferable that an adhesive component for bonding the cover film 9 does not remain at the end portion of the conductive material 7 when the cover film 9 is peeled off. That is, the end portion of the conductive material 7 functions as the bump 8 in the later-described multi-layering, and therefore, it is possible to prevent the conductivity from being hindered by the adhesive component remaining in the conductive material 7. Is preferred. For this reason, when providing the cover film 9, it is preferable to press-press with a roll laminator etc. through the adhesion layer which consists of an adhesive component with comparatively weak adhesive force. The adhesion layer at this time can provide sufficient adhesion between the protective film 5 and the cover film 9 as described above, and does not remain attached to the end of the conductive material 7. As long as it can be used as appropriate, it is not particularly limited, but resins commonly used in adhesives, such as vinyl resins, urethane resins, acrylic resins, polyamide resins, etc. alone or as a mixture, What adjusted the adhesive force can be used.

  Through the above steps, the conductor wiring 3, the hard insulating layer 2, the adhesive layer 4, the protective film 5 and the cover film 9 are laminated and formed in this order, and penetrate the hard insulating layer 2, the adhesive layer 4 and the protective film 5. At the same time, a sheet material 14 for producing a multilayer printed wiring board is obtained that has holes 6 that are closed at both ends by the conductor wiring 3 and the cover film 9 and filled with the conductive material 7 inside.

  A method for manufacturing the multilayer printed wiring board 18 using the sheet material 14 for manufacturing the multilayer printed wiring board thus obtained will be described.

  The surface of the conductor wiring 3 of the multilayer printed wiring board manufacturing sheet material 14 obtained as described above is roughened. The roughening treatment can be performed by a wet treatment using a treatment liquid 10 as shown in FIG. Examples of the roughening treatment include soft etching using a soft etching solution composed of sulfuric acid / hydrogen peroxide, etching using an organic acid, and needle-like plating using copper-nickel-phosphorus. It is done.

  When performing such surface roughening treatment, the conductive material 7 filled in the hole 6 is closed at one end by the conductor wiring 3 and at the other end by the cover film 9, It is not exposed to the outside, and therefore, it is not exposed to the processing liquid 10 such as the soft etching liquid in the roughening process, and the conductive material 7 is prevented from being deteriorated and damaged. The electrical reliability of the via hole 12 can be improved.

  In the above roughening treatment, the treatment liquid 10 such as a soft etching solution for the roughening treatment is the surface on which the conductor wiring 3 is formed, that is, the side on which the cover film 9 is provided. It is preferable to perform a chemical treatment for spraying the treatment liquid 10 by spraying with a spray or the like toward only the opposite surface. In this case, the treatment liquid 10 can be prevented from entering the hole 6 from the gap between the cover film 9 and the protective film 5 and the conductive material 7 is exposed to the treatment liquid 10. Can be reliably prevented, and the protection of the conductive material 7 in the hole 6 can be sufficiently achieved. Here, the sheet material is often formed as a thin material having a thickness of 0.20 mm or less. For this reason, the processing liquid 10 for the surface roughening treatment is carried out while the sheet material is conveyed on a horizontal conveyance line such as a conveyor. It is preferable to perform the roughening treatment by spraying from the side where the conductor wiring 3 is formed.

  The degree of roughening of the conductor wiring 3 can be adjusted as appropriate so that interlayer adhesion described later and conduction reliability with the via hole 12 can be secured, but preferably the surface roughness Rz (excessive). Point average roughness: JIS B 0601) is in the range of 0.1 to 3.0 μm.

  Next, as shown in FIG. 2B, the cover film 9 and the protective film 5 are sequentially peeled and removed, whereby the multilayer substrate 16 is obtained. At this time, the end portion of the conductive material 7 filled in the hole of the protective film 5 is in a state of protruding from the adhesive layer 4, and this protruding end portion is for securing conduction between layers at the time of lamination molding. Bumps 8 are formed. The protruding dimension of the bump 8 is formed to the same dimension as the thickness of the protective film 5 as described above, and the dimension is preferably in the range of 5 to 100 μm.

  In manufacturing the multilayer printed wiring board 18, a plurality of substrates 15 are laminated and formed. As the substrate 15, the multilayer substrate 16 formed by the above method is used. At this time, only the multi-layer substrate 16 may be used as the substrate 15, but one or a plurality of multi-layer substrates 16 may be used in combination with one or a plurality of other substrates 17 formed by other methods. it can.

  As the other substrate 17 to be used in combination, one in which the conductor wiring 3, the hard insulating layer 2, and the adhesive layer 4 are laminated and formed can be used. For example, in the manufacturing process of the multilayer substrate 16, the holes 6 And the step of filling the hole 6 with the conductive material 7 can be omitted, or the step of performing the roughening treatment on the conductor wiring 3 can be omitted. That is, for example, when the substrate 17 for forming a layer that does not have the via hole 12 is manufactured, the step of forming the hole 6 and filling the hole 6 with the conductive material 7 is omitted to manufacture the substrate 17. When the substrate 17 for forming the conductor wiring 3 that is not roughened on the outermost layer of the multilayer printed wiring board 18 is manufactured, a process of performing a surface roughening process on the conductor wiring 3 is performed. This substrate 17 can be fabricated without the above.

  When the plurality of substrates 15 are laminated and formed, for example, the plurality of substrates 15 are temporarily fixed by positioning between the substrates 15 by a welding method or a pin laminating method using guide holes and guide pins. By heat-pressing, they can be integrated and laminated. At this time, as the heat press, it is preferable to perform a vacuum heat press in which the heat and pressure treatment is performed in a reduced pressure atmosphere.

  By such heat and pressure treatment, the adhesive layer 4 of each substrate 15 is once melted and then cured and integrated between the layers, and the adhesive layer 4 overlapped with the conductor wiring 3 has its conductor wiring. In this case, the insulating layer 11 of the multilayer printed wiring board 18 is formed by the hard insulating layer 2 and the adhesive layer 4. In addition, the via hole 12 is formed by the conductive material 7 filled in the hole 6. When the conductive material 7 is formed by a conductive paste at this time, the conductive paste is thermally cured. Thus, a via hole 12 (interstitial via hole; IVH) is formed.

  According to such a method, the multilayer printed wiring board 18 in which the interstitial via hole is formed at an arbitrary position can be manufactured by collectively laminating and integrating the plurality of substrates 15. .

  In the example shown in FIG. 2C, four substrates 15 are laminated. In the illustrated example, two multilayered substrates 16 having the holes 6 filled with the conductive material 7 and having the surface roughened on the conductor wiring 3 formed as described above are stacked, and the conductive material is formed on both sides thereof. A substrate 17 having a hole 6 filled with 7 but not subjected to a roughening treatment is stacked on the conductor wiring 3.

  Here, the inner two multilayer substrates 16 are such that the surfaces on which the bumps 8 are formed (sides on which the conductor wiring 3 is not formed) are opposed to each other, and at this time predetermined bumps are formed. The eight are arranged so as to overlap each other. The substrates 17 arranged on both sides of the substrate 17 are overlapped so that the surface on which the bumps 8 are formed faces the surface on the side on which the conductor wiring 3 of the multilayer substrate 16 is formed. At this time, the predetermined bumps 8 are aligned and arranged so as to overlap the predetermined positions of the conductor wiring 3.

  When the multilayer printed wiring board 18 is manufactured by laminating and integrating the substrates 15 including the multilayer substrate 16 as described above, the roughened conductor wiring 3 on the multilayer substrate 16 is formed as shown in FIG. However, the adhesion between the layers is improved by bonding to the adhesive layer 4 of the substrate 15 superimposed thereon. In addition, the bumps 8 of the conductive material 7 are joined to the roughened conductor wiring 3, and the conductive material 7 and the conductor wiring 3 are joined with good adhesion. When the conductive material 7 is heated and cured in this state, high conduction reliability is obtained between the via hole 12 formed of the conductive material 7 and the conductor wiring 3.

  At this time, the roughening treatment of the conductor wiring 3 is performed by forming the adhesive layer 4, attaching the protective film 5, forming the hole 6, filling the hole 6 with the conductive material 7, and attaching the cover film 9. For this reason, the conductor wiring 3 is subjected to a roughening treatment immediately before the multilayering treatment is performed, and then the cover film 9 and the protective film 5 are quickly peeled and removed to provide a multilayer substrate. 16 can be produced and subjected to multilayering treatment. As a result, after the roughening treatment, the rough surface of the conductor wiring 3 becomes a conductor when the substrate is placed on the table of a flat processing machine in the case of drilling by laser or paste printing by printing. Lamination can be performed before the surface of the conductor wiring 3 roughened at the corners becomes smooth due to the roughened surface of the wiring 3 being crushed, and adhesion between the layers, the conductor wiring 3 and the via hole can be formed. The multilayer printed wiring board 18 having excellent conduction reliability with the circuit 12 can be obtained.

  In addition, during the roughening treatment of the conductor wiring 3, the adhesive layer 4 is protected by the protective film 5, and the conductive material 7 is protected by the protective film 5 and the cover film 9, which is used for the roughening treatment. The adhesive layer 4 and the conductive material 7 are not exposed to the treatment liquid 10 or the like, and the deterioration of the adhesive layer 4 and the conductive material 7 can be prevented.

  Further, in the portion where the bumps 8 of the multilayer substrate 16 are overlapped with each other, the conductive material 7 of the two multilayer substrates 16 are joined together by the bump 8 to form an integral via hole 12. Yes, at this time, high conduction reliability is imparted to the joint portion.

  Although the specific Example of this invention is shown below, this invention is not limited to the following Example.

(Example)
A metal film 1 (copper foil) laminated and formed on one surface of a hard insulating layer 2 made of a cured epoxy resin composition based on a glass woven fabric (FR-4 grade glass woven substrate epoxy resin) Single-sided copper-clad laminate; manufactured by Matsushita Electric Works, product number “R-1661”, hard insulation layer 2 thickness 0.1 mm, copper foil thickness 18 μm), and rolls adhesive containing epoxy resin on the hard insulation layer 2 The adhesive layer 4 was formed by coating at a coating thickness of 30 μm with a coater and heating at 60 ° C. until tackiness disappeared. Next, using a laminator, at a temperature of 80 ° C. and a pressure of 0.05 MPa, the protective film 5 (polyethylene terephthalate film; manufactured by Toray Industries, Inc., product number “type T60”, thickness 38 μm, surface roughness Rz = 30 nm The sheet material as shown in FIG. 1A was prepared by laminating on the surface.

  Next, a photosensitive dry film was laminated on the copper foil, exposed and developed. Further, etching was performed using a cupric chloride solution, and then the dry film was peeled off using a sodium hydroxide solution to form a conductor wiring 3 as shown in FIG.

  Next, as shown in FIG. 1 (c), the diameter of 100 μm reaches the conductor wiring 3 through the protective film 5, the adhesive layer 4 and the hard insulating layer 2 by drilling with a carbon dioxide laser from the protective film 5 side. Hole 6 was formed. The holes 6 were further irradiated with a UV laser to remove residues.

Next, as shown in FIG. 1D, the hole 6 is filled with a conductive paste mainly composed of silver powder by a screen printing method, and then, as shown in FIG. Then, a polyethylene terephthalate cover film 9 having an adhesive layer made of polyolefin (“ZACROS-PC-542T” manufactured by Fujimori Kogyo Co., Ltd.) was attached with a roll laminator at a pressure of 0.49 MPa (5 kgf / cm ² ). .

  Next, as shown in FIG. 2A, an etching treatment agent (manufactured by MEC, micro-etching treatment agent “MEC etch bond CZ8100”) is sprayed only from the conductor wiring 3 side as the treatment liquid 10, and the surface roughness Rz is The soft etching process was performed so that it might become 2 micrometers.

  Next, the cover film 9 and the protective film 5 are peeled off so that the bumps 8 formed from the ends of the conductive paste protrude from the surface of the adhesive layer 4 as shown in FIG. A multilayer substrate 16 was obtained. Two multilayer substrates 16 were produced. The multi-layer substrate 16 was flat without warping or twisting.

  Further, two substrates 17 were produced in the same manner as described above except that the conductor wiring 3 was not roughened.

  Then, as shown in FIG. 2C, four substrates 15 (multilayer substrate 16 and substrate 17) were overlapped and temporarily fixed by a pin laminating method for alignment. Since each of the multi-layered substrates 15 and 16 was flat with no warping or twisting, the alignment could be easily performed.

  Next, a heat press was applied under reduced pressure at 180 ° C. for 1 hour to obtain a multilayer printed wiring board 18 as shown in FIG.

(Comparative example)
The same materials as in the examples were used except that the following method was applied.

  First, a photosensitive dry film was laminated on the metal film 1 having the metal film 1 formed on one surface of the hard insulating layer 2 (see FIG. 3A), exposed and developed. Further, etching is performed using a cupric chloride solution, and then the dry film is peeled off using a sodium hydroxide solution to form the conductor wiring 3, and then the etching treatment agent is used as the processing liquid 10 on the conductor wiring 3 side. A soft etching process was performed so that the surface roughness Rz was 2 μm (see FIG. 3B).

  Next, an adhesive containing an epoxy resin was applied to the hard insulating layer 2 with a roll coater at a coating thickness of 30 μm, and heated at 60 ° C. until tackiness disappeared to form an adhesive layer 4. Next, using a laminator, the protective film 5 was laminated on the surface of the adhesive layer 4 at a temperature of 80 ° C. and a pressure of 0.05 MPa to produce a sheet material as shown in FIG.

  Next, as shown in FIG. 3 (d), a diameter of 100 μm reaches the conductor wiring 3 through the protective film 5, the adhesive layer 4 and the hard insulating layer 2 by drilling with a carbon dioxide gas laser from the protective film 5 side. Hole 6 was formed. The holes 6 were further irradiated with a UV laser to remove residues.

  Next, as shown in FIG. 3 (e), the conductive paste mainly composed of silver powder is filled in the holes 6 by the screen printing method, and then the protective film is peeled off to form the end of the conductive paste. The bump 8 to be projected was projected from the surface of the adhesive layer 4 to obtain a substrate. Two sheets of this substrate were produced.

  Further, two substrates were produced in the same manner as described above except that the conductor wiring 3 was not roughened.

  Then, as shown in FIG. 2 (c), the four substrates were overlapped and temporarily fixed by a pin laminating method for alignment.

  Subsequently, a heat-pressing process was performed at 180 ° C. for 1 hour under reduced pressure to obtain a multilayer printed wiring board.

(Evaluation)
For the examples and comparative examples, 16 samples each having a 25 mm square in plan view were prepared.

  Each sample was held in a PCT test tank maintained at 121 ° C., 2.0 atm, and 100% RH for 2 hours, and then solder float was performed at 260 ° C. for 20 seconds.

  About the sample after this process, the pass / fail determination was performed by the presence or absence of the swelling of the conductor wiring of an inner layer and the part of an insulating layer.

  As a result, in the example, the number of samples in which defects occurred was 0, whereas in the comparative example, defects occurred in 10 samples.

(A) thru | or (e) is a schematic sectional drawing which shows an example of embodiment of this invention. (A) thru | or (d) is a schematic sectional drawing which shows an example of embodiment same as the above. (A) thru | or (f) is a schematic sectional drawing which shows an example of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal film 2 Hard insulating layer 3 Conductor wiring 4 Adhesive layer 5 Protective film 6 Hole 7 Conductive material 9 Cover film 10 Treatment liquid 12 Via hole 14 Sheet material for multilayer printed wiring board production 15 Substrate 16 Multilayer substrate 18 Multilayer print Wiring board

Claims (4)

(1) A metal film is laminated on one surface of the hard insulating layer, an adhesive layer that can be temporarily melted by heating is formed on the other surface, and a protective film is laminated on the outer surface, and the metal film is patterned. Forming a conductor wiring by applying,
(2) A step of forming a hole through which the conductor wiring is exposed at the bottom while penetrating from the protective film side and penetrating the protective film, the adhesive layer, and the hard insulating layer;
(3) filling the hole with a conductive material;
(4) Laminating a cover film so as to close the hole in the outer layer of the protective film;
(5) a step of roughening the surface of the conductor wiring;
(6) The process of peeling the said cover film,
(7) peeling the protective film and causing the conductive material to protrude from the adhesive layer;
(8) A step of laminating and integrally forming a plurality of substrates including the multilayer substrate produced through the steps (1) to (7),
A method of manufacturing a multilayer printed wiring board, wherein   The method for producing a multilayer printed wiring board according to claim 1, wherein the cover film is laminated by roll lamination in the step (4) of claim 1.   The roughening step of the conductor wiring in the step (5) of claim 1 is a step of providing irregularities on the surface of the conductor wiring, and wet processing in which the treatment liquid is sprayed only from the surface side on which the conductor wiring is formed. The method for producing a multilayer printed wiring board according to claim 1, wherein the chemical solution treatment is performed. (1) A metal film is laminated on one surface of the hard insulating layer, an adhesive layer that can be temporarily melted by heating is formed on the other surface, and a protective film is laminated on the outer surface, and the metal film is patterned. Forming a conductor wiring by applying,
(2) A step of drilling from the protective film side to form a hole that penetrates the protective film, the adhesive layer, and the hard insulating layer and exposes the conductor wiring on the bottom surface (3) A conductive material in the hole Filling the step,
(4) Laminating a cover film so as to close the hole in the outer layer of the protective film;
A sheet material for producing a multilayer printed wiring board, wherein the sheet material is produced by sequentially passing through the steps.

Images