JP4276015B2 - Sinking wiring board and manufacturing method thereof - Google Patents

Description

The present invention relates to a method for manufacturing a sedimented wiring board having a sedimented wiring in which at least a part of a wiring bottom of a wiring path is settled from the surface of a wiring board substrate with respect to the arrangement position of the wiring part of the wiring board .

  Conventionally, many methods of lamination have been proposed for printed wiring boards and the like, and a method of bonding using an adhesive or the like is used as the lamination method. Patent Document 1 discloses a method for producing a metal laminated film by laminating a metal thin film on a polymer film and bonding a metal foil, and Patent Document 2 discloses excessive heat and pressure. There is shown a method by activated joining in which different kinds of metal plates are joined without addition.

Prior art documents relating to the present application include the following.
Japanese Patent Laid-Open No. 2002-113811 JP-A-1-224184

  However, when an adhesive is used, there are problems such as deterioration of electrical characteristics such as characteristic impedance due to the adhesive layer, and an increase in thickness and weight of the adhesive layer, which is not suitable for light weight and thinning. In view of such a technical background, an object of the present invention is to provide a printed wiring board that can be laminated without using an adversely affecting adhesive.

The method for producing a sedimented wiring board according to the present invention is a method for producing a sedimented wiring board formed by laminating three layers of a base material, an intermediate layer, and a wiring material, and a bonding planned surface of a wiring material made of metal is formed by sputter etching. An activation process, an activation process of a substrate surface made of an organic polymer by sputter etching, and an intermediate layer of the same metal as the wiring material is formed on the activated substrate by sputtering. A step of abutting the intermediate layer and the activated wiring material and cold-rolling and laminating and joining to produce a laminated material, and etching the wiring material of the laminated material And a step of manufacturing the wiring pattern and a step of hot pressing the laminated material to settle the wiring pattern on the base material .

  As described above, since at least a part of the wiring bottom of the wiring path is settled from the substrate surface, it is possible to stack without exerting unnecessary stress on the wiring path when stacking is performed. Adverse effects can be prevented. In addition, no adhesive is used for the lamination, and further weight reduction and thickness reduction can be achieved.

  Hereinafter, embodiments of the present invention will be described. FIG. 1 is a schematic cross-sectional view showing an embodiment of a sinking wiring board according to the present invention, in which a wiring path 33 is arranged on one side of a base material 24 and the bottom of the wiring path 33 is sinking from the surface of the base material 24. Is shown. FIG. 2 is a schematic cross-sectional view showing another embodiment of the sinking wiring board of the present invention, and shows an example in which the wiring board has two layers and two layers of base materials.

  The sinking wiring board 40 shown in FIG. 1 can be manufactured as follows. First, the laminated material 20 obtained by laminating the wiring material 23 to be the wiring path on the base material 24 shown in FIG. 3 is subjected to an etching process or the like to form a wiring path 33 having a required wiring pattern, as shown in FIG. A flexible wiring board 30 is manufactured. Next, after the base material 24 is sufficiently heated to have flexibility by hot pressing or the like, and is allowed to settle from the surface of the base material 24 so as not to give stress concentration that affects the wiring path 33 such as breakage. The fixed wiring board 40 as shown in FIG. 1 can be manufactured by fixing. The degree of sedimentation may be such that the surface of the wiring path 33 substantially coincides with the surface of the base material 24 as shown in FIG. 1, or the surface of the wiring path 33 protrudes from the surface of the base material 24 as shown in FIG. Alternatively, as shown in FIG. 6, the surface of the wiring path 33 may be submerged than the surface of the base material 24, and the surface of the wiring path 33 may be appropriately selected depending on the application application of the sedimented wiring board, the presence or absence of lamination, the lamination method, and the like Can do. If the base material 24 is a thermoplastic material, the wiring board 30 is heated to soften the base material 4, and then the wiring path 33 is pressed using a flat plate or the like to sink the wiring path 33. Can do. If the base material 24 is a thermosetting material, if the wiring path 33 is sufficiently soft enough to settle, the base material 24 is set after the wiring path 33 is settled from the surface of the base material 24. The sinking wiring board 40 can be manufactured by curing 24.

  The laminated material 20 may be obtained by laminating the wiring material 23 on the base material 24 via an adhesive layer, or may realize lamination by using activated bonding as described in Patent Document 1. In the laminating method using the activation treatment, the surface to be joined of the base material 24 installed on the rewinding reel is activated by the activation treatment device in the vacuum chamber. In the same manner, the bonding planned surface side of the wiring member 23 installed on the rewinding reel is activated by the activation processing apparatus. Next, an intermediate layer is formed on the surface of the base material 24 by sputtering using a film forming unit. Thereafter, lamination can be achieved by laminating and bonding the film-formed substrate 24 and the activated wiring material 23. At this time, the laminated material 20 can be manufactured by making the intermediate layer the same material as the wiring material 23. Similarly, a laminated material 22 having wiring materials on both sides as shown in FIG. 7 can be manufactured.

In the activation treatment, the base material 24 and the wiring member 23 loaded in the vacuum chamber are brought into contact with one electrode A grounded and grounded, and the other electrode B insulated and supported is 10 to 1 ×. Substrate 24 and wiring in contact with electrode A exposed to plasma generated by glow discharge by applying an alternating current of 1 to 50 MHz in an extremely low pressure inert gas atmosphere of 10 ⁻³ Pa. This can be achieved by performing a sputter etching process so that the area of each material 23 on the planned bonding surface side is effectively 1/3 or less of the area of the electrode B. As the inert gas, argon, neon, xenon, krypton, or a mixture containing these can be used. Argon is preferable. If the inert gas pressure is less than 1 × 10 ⁻³ Pa, stable glow discharge is difficult to perform and high-speed etching is difficult, and if it exceeds 10 Pa, the activation treatment efficiency decreases. If the alternating current applied is less than 1 MHz, it is difficult to maintain a stable glow discharge, and continuous etching is difficult, and if it exceeds 50 MHz, oscillation tends to occur and the power supply system becomes complicated, which is not preferable. Moreover, in order to etch efficiently, it is necessary to make each area | region of the base material 24 and the wiring material 23 which contacted the electrode A effectively smaller than the area of the electrode B, By making it effective 1/3 or less, Etching can be performed with sufficient efficiency.

In the film forming unit, the sputtering process can be performed by effectively increasing the area on the substrate 24 side, contrary to the activation processing apparatus. That is, the substrate 24 loaded in the vacuum chamber is brought into contact with one electrode A which is grounded, and between the other electrode C which is insulated and supported, an extremely low pressure of 10 to 1 × 10 ⁻³ Pa is avoided. In an active gas atmosphere, an alternating current of 1 to 50 MHz is applied to cause glow discharge, and the area of the substrate 24 in contact with the electrode A exposed to the plasma generated by the glow discharge is effectively equal to that of the electrode C. A film can be formed by performing a sputtering treatment so that the area is three times or more. As the inert gas, argon, neon, xenon, krypton, or a mixture containing these can be used. Argon is preferable. If the inert gas pressure is less than 1 × 10 ⁻³ Pa, stable glow discharge is difficult to be performed, and if it exceeds 10 Pa, the sputtering efficiency is lowered. If the alternating current to be applied is less than 1 MHz, it is difficult to maintain a stable glow discharge and continuous sputtering is difficult, and if it exceeds 50 MHz, oscillation tends to occur and the power supply system becomes complicated, which is not preferable. In order to perform sputtering efficiently, it is necessary to effectively make the area of the base material 24 in contact with the electrode A larger than the area of the electrode C. By effectively increasing the area to 3 times or more, a film can be formed with sufficient efficiency. Is possible.

  Laminate bonding is achieved by abutting and superimposing the film-formed base material 24 and the activated wiring material 23 so as to face each other, and performing cold pressure welding with a pressure welding unit. be able to. Lamination bonding at this time can be performed at a low temperature, and adverse effects such as structural changes and formation of alloy layers on the base material 24, the wiring material 23, and the joint can be reduced or eliminated. When T is the temperature (° C.) of the base material 24 and the wiring material 23, a good pressure contact state is obtained at 0 ° C. <T <300 ° C. If it is 0 ° C. or lower, a special cooling device is required, and if it is 300 ° C. or higher, adverse effects such as changes in structure occur. More preferably, 0 ° C. <T <200 ° C. More preferably, 0 ° C. <T <150 ° C. The rolling rate R (%) is preferably 0.01% ≦ R ≦ 30%. If it is less than 0.01%, sufficient bonding strength cannot be obtained, and if it exceeds 30%, deformation becomes large, which is not preferable for processing. More preferably, 0.1% ≦ R ≦ 3%. More preferably, 1% <R ≦ 3%.

  The material of the substrate 24 is not particularly limited as long as it is a material capable of producing a sedimented wiring board, and can be appropriately selected and used depending on the use of the sedimented wiring board. For example, an organic polymer substance such as plastic or a mixture obtained by mixing powder or fiber with plastic can be used. When the sedimented wiring board is applied to a printed wiring board or the like, polyimide such as polyimide, polyetherimide, polyethylene terephthalate, aromatic polyamide such as nylon, or the like can be used. The heat-resistant temperature of the base material 24 can be defined by a melting point, a softening point, a glass transition point, and the like, and can be appropriately selected and used depending on the use and material of the sedimented wiring board. Furthermore, depending on the material, the deflection temperature under load, the deflection temperature under heating, the Vicat softening temperature, etc. can be applied as the softening point.

  Examples of the plastic include acrylic resin, amino resin (melamine resin, urea resin, benzoguanamine resin, etc.), allyl resin, alkyd resin, urethane resin, liquid crystal polymer (LCP, Liquid Crystal Polymer), EEA resin (Ethylene Ethylacrylate resin), AAS resin (Acrylonitrile Acrylate Styrene resin), ABS resin (Acrylonitrile Butadiene Styrene resin), ACS resin (Acrylnitrile Chlorinated polyethylene Styrene resin), AS resin (Acrylonitrile Styrene resin), ionomer resin, ethylene polytetrafluoroethylene copolymer, epoxy resin , Silicon resin, styrene butadiene resin, phenol resin, fluoroethylene propylene, fluorine resin, polyacetal, polyarylate, polyamide (6 nylon, 11 nylon, 12 nylon, 66 nylon, 610 nylon, 6 12 nylon, etc.), polyamideimide, polyimide, polyetherimide, polyetheretherketone, polyethersulfone, polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycyclohexine dimer terephthalate, polytrimethylene terephthalate, polytrimethylene) Methylene naphthalate, etc.), polyolefin (polyethylene, polypropylene, etc.), polycarbonate, polychlorotrifluoroethylene, polysulfone, polystyrene, polyphenylene sulfide, polybutadiene, polybutene, polymethylpentene, and the like can be applied.

  Further, the thickness of the base material 24 is appropriately selected depending on the use of the sinking wiring board. For example, it is 1-1000 micrometers. When the thickness is less than 1 μm, it is difficult to produce the substrate, and when it exceeds 1000 μm, the substrate becomes heavy. If the use of the sinking wiring board is a flexible printed wiring board or the like, for example, the one in the range of 3 to 300 μm can be applied. If it is less than 3 μm, the mechanical strength is poor, and if it exceeds 300 μm, the flexibility is poor. Preferably, it is 10-150 micrometers. More preferably, it is 20-75 micrometers.

  The material of the wiring material 23 may be a conductive wiring material, a resistance wiring material, or a laminated wiring material of these. The laminated wiring material is obtained by laminating a plurality of layers of conductive wiring materials, resistance wiring materials, and the like. For example, a film made of a resistance wiring material is laminated on a conductive wiring material such as a foil by plating, vapor deposition, sputtering, or the like. . Moreover, it can also join by performing activation joining to the conductive wiring material of foil, resistance wiring material, etc. In the laminating method using the activation treatment, the surface to be joined of the foil material installed on the rewinding reel is activated by the activation treatment device in the vacuum chamber. Similarly, the other foil material is activated. Thereafter, lamination can be achieved by laminating and joining the activated foils.

In the activation treatment, the foil materials loaded in the vacuum chamber are brought into contact with one electrode A which is grounded, and 10 to 1 × 10 ⁻³ Pa between the other electrode B which is insulated and supported. In the extremely low pressure inert gas atmosphere, an alternating current of 1 to 50 MHz is applied to perform glow discharge, and the respective bonding planned surfaces of the foil material in contact with the electrode A exposed in the plasma generated by the glow discharge Can be achieved by performing a sputter etching process so that the area is effectively １ ／ or less of the area of the electrode B. As the inert gas, argon, neon, xenon, krypton, or a mixture containing these can be used. Argon is preferable. If the inert gas pressure is less than 1 × 10 ⁻³ Pa, stable glow discharge is difficult to perform and high-speed etching is difficult, and if it exceeds 10 Pa, the activation treatment efficiency decreases. If the alternating current applied is less than 1 MHz, it is difficult to maintain a stable glow discharge, and continuous etching is difficult, and if it exceeds 50 MHz, oscillation tends to occur and the power supply system becomes complicated, which is not preferable. In addition, in order to perform etching efficiently, it is necessary to make each area of the foil material in contact with the electrode A effectively smaller than the area of the electrode B. Etching with sufficient efficiency by making it effective 1/3 or less. It becomes possible.

  Laminate bonding can be achieved by bringing the two foil materials that have been activated into contact with each other so that the surfaces to be bonded face each other and overlapping them, and then performing cold pressure welding with a pressure welding unit. In this case, the lamination bonding can be performed at a low temperature, and adverse effects such as a change in structure and formation of an alloy layer at the foil members and at the bonding portion can be reduced or eliminated. When T is the temperature (° C.) of the foil material, a good pressure contact state is obtained at 0 ° C. <T <300 ° C. If it is 0 ° C. or lower, a special cooling device is required, and if it is 300 ° C. or higher, adverse effects such as changes in structure occur. More preferably, 0 ° C. <T <200 ° C. More preferably, 0 ° C. <T <150 ° C. The rolling rate R (%) is preferably 0.01% ≦ R ≦ 30%. If it is less than 0.01%, sufficient bonding strength cannot be obtained, and if it exceeds 30%, deformation becomes large, which is not preferable for processing. More preferably, 0.1% ≦ R ≦ 3%. More preferably, 1% <R ≦ 3%.

  The material of the conductive wiring material is not particularly limited as long as it is a material capable of producing a sedimented wiring board and has excellent conductivity, and can be appropriately selected and used depending on the use of the sedimented wiring board. For example, a metal having excellent conductivity that is solid at room temperature (for example, Al, Cu, Ag, Pt, Au, etc.) or an alloy having excellent conductivity including at least one of these metals (for example, JIS Specified alloys etc.) can be applied. The specific resistance of the conductive wiring material is preferably in the range of 1 to 20 μΩ · cm at 20 ° C., and more preferably in the range of 1 to 10 μΩ · cm. If the use of the sinking wiring board is a printed wiring board or the like, as the conductive wiring material, Cu, Al, etc., which are metals having excellent conductivity, and alloys having excellent conductivity including at least one of these metals are used. Etc. can be applied. That is, a copper material, an aluminum material, or the like can be applied as the conductive wiring material. Examples of copper materials include Cu, oxygen-free copper specified in JIS, tough pitch copper, phosphor bronze, brass, copper-beryllium alloys (for example, alloys of 2% by weight beryllium and the remainder being copper), copper-silver, and the like. As an aluminum material such as an aluminum alloy (for example, an alloy of 3 to 5% by weight of silver, the balance being copper, etc.), aluminum alloy plates such as 1000 series and 3000 series defined in JIS can be applied in addition to Al. .

  The material of the resistance wiring material is not particularly limited as long as it is a material capable of manufacturing a sinking wiring board and has a required specific resistance, and can be appropriately selected and used depending on the use of the sinking wiring board. For example, an alloy that is solid at room temperature and has a required specific resistance (for example, an alloy specified in JIS) can be applied. The specific resistance of the resistance wiring material is preferably in the range of 30 to 300 μΩ · cm at 20 ° C. If the use of the sinking wiring board is a printed wiring board or the like, a resistance alloy material having a required specific resistance capable of forming a resistance portion in the wiring pattern can be applied. Examples of the resistance alloy material include a copper-manganese alloy (for example, manganese 12 to 15% by weight, nickel 2 to 4% by weight, the balance of copper and the like), a copper-nickel alloy (for example, copper 55% by weight, nickel). 45% by weight alloy, etc.), nickel-chromium alloy (for example, nickel 80% by weight, chromium 20% by weight alloy, etc.), nickel-phosphorus alloy (for example, phosphorus 1-20% by weight, the balance being nickel) Alloy, etc.), nickel-boron-phosphorus alloy (for example, 2% by weight of boron, 8-16% by weight of phosphorus, etc.), iron-chromium alloy (for example, 20% by weight of chromium, aluminum 3) % By weight, the balance being iron, etc.), iron-nickel alloys, iron-carbon alloys and the like can be applied.

  Further, the thickness of the conductive wiring material and the resistance wiring material is not particularly limited as long as a sedimented wiring board can be manufactured, and can be appropriately selected and used depending on the use of the sedimented wiring board. For example, it is preferable that it is 1-1000 micrometers. When the conductive wiring material or the resistance wiring material is made of a plate material such as a foil, if it is less than 1 μm, it becomes difficult to manufacture as a conductive wiring material or a resistance wiring material. More preferably, it is 10-500 micrometers. The conductive wiring material and the resistance wiring material may be a plate material such as electrolytic foil or rolled foil, or may be a laminate of film materials by plating or vapor deposition.

  The sinking wiring board of the present invention is also suitable for the lamination shown in FIG. When laminating by laminating multiple layers of single-layer sedimented wiring boards and fusing the substrates together by hot pressing etc., the stress on the wiring path itself can be reduced or suppressed, thus breaking the wire Adverse effects such as can be eliminated or reduced. For this reason, it is not necessary to use an adhesive that may adversely affect the characteristic impedance. If necessary, activation treatment by plasma discharge such as glow discharge or corona discharge can be used on the surface of the single-layer sedimented wiring board. When corona discharge or the like is used, activation treatment is possible not only in a reduced pressure state but also in the vicinity of atmospheric pressure, and the atmosphere is possible not only in an inert gas but also in air. The necessity and type of the activation treatment can be appropriately selected depending on the configuration and application of the sinking wiring board.

  Further, for the sinking wiring board, not only the two-layer laminated material 20 in which the wiring material 23 is laminated on one side of the base material 24 but also the three-layer laminated material 22 in which the wiring material 23 is laminated on both sides of the base material 24 are used. Can do. Etching is performed on the wiring members 23 arranged on both surfaces of the laminated material 22 to form wiring paths 33 and 34 to manufacture a wiring board 32, which is hot-pressed to have wiring paths on both surfaces. A sinking wiring board can be formed. For example, a sedimentation wiring board 40 having a wiring path on one side can be stacked on one side or both sides of the sedimentation wiring board having wiring paths on both sides. In the sinking wiring board, since the wiring path is settled or buried in the substrate, it is possible to suppress or reduce the positional deviation of the wiring path itself when increasing the number of layers, which is effective in improving the positional accuracy.

  Further, when the wiring material 23 is made of a laminated wiring material having a laminated structure in which the upper layer is a conductive wiring material and the lower layer is a resistance wiring material, the conductive wiring material portion on the surface of the settled wiring board using this is subjected to an etching process to conduct the conductive wiring. By removing the material part and forming the resistance wiring part consisting only of the resistance wiring material part, it is possible to form the resistance part on the sinking wiring board, and it is possible to omit the mounting of the resistance element, etc. Can be reduced.

  Substrates having different heat resistance temperatures can be used as the base material of the sinking wiring board of the present invention. When laminating sedimentation wiring boards, using a base material with a high heat resistance temperature on the inside and using a base material with a low heat resistance temperature on the outside eliminates the need to heat the entire laminated wiring wiring board uniformly. It is possible to laminate the wiring path of the inner sedimentation wiring board while it is fixed without being unstable by heating.

  A multilayered circuit can be formed by applying through holes, interlayer conductive processing, etc., to the multi-layered sinking wiring board manufactured in this way. A multilayer printed wiring board can be obtained by using as a material. For this reason, it is suitable for printed wiring boards (rigid printed wiring boards, flexible printed wiring boards, etc.) and the like, and also for IC packages such as IC cards, CSP (chip size package or chip scale package) and BGA (ball grid array). Can be applied.

  Examples will be described below. A wiring board 30 having a predetermined pattern was manufactured by performing an etching process on the laminate 20 using a liquid crystal polymer having a thickness of 100 μm as the base material 24 and an electrolytic copper foil having a thickness of 50 μm as the wiring material 23. This was subjected to hot pressing, and the wiring portion was buried in the liquid crystal polymer to form a sedimented wiring board 40. Next, another settling wiring board was prepared and overlapped with the above settling wiring board and subjected to hot press processing to produce a two-layer settling wiring board 40. This was subjected to through-hole processing to produce a two-layer printed wiring board.

  As described above, the sinking wiring board of the present invention is formed by sinking at least a part of the wiring bottom of the wiring path from the substrate surface. For this reason, it is possible to laminate without causing unnecessary stress on the wiring path when the lamination is attempted, and it is possible to prevent an adverse effect such as disconnection, and no adhesive is used in the lamination. Can be reduced in weight and thickness, and is suitable for application to circuit boards and the like.

It is a schematic sectional drawing which shows one Embodiment of the sedimentation wiring board of this invention. It is a schematic sectional drawing which shows other one Embodiment of the sedimentation wiring board of this invention. It is a schematic sectional drawing which shows one Embodiment of a laminated board. It is a schematic sectional drawing which shows one Embodiment of a wiring board. It is a schematic sectional drawing which shows another one Embodiment of the sedimentation wiring board of this invention. It is a schematic sectional drawing which shows another one Embodiment of the sedimentation wiring board of this invention. It is a schematic sectional drawing which shows other one Embodiment of a laminated board. It is a schematic sectional drawing which shows other one Embodiment of a wiring board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Laminated material 22 Laminated material 23 Wiring material 24 Base material 30 Wiring board 32 Wiring board 33 Wiring path 34 Wiring path 40 Precipitation wiring board 42 Precipitation wiring board 43 Precipitation wiring board 44 Precipitation wiring board

Claims (1)

A method for manufacturing a sedimented wiring board in which three layers of a base material, an intermediate layer, and a wiring material are laminated,
A process of activating the bonding planned surface of the wiring material made of metal by sputter etching;
A step of activating the substrate surface made of an organic polymer by sputter etching;
Forming an intermediate layer of the same metal as the wiring material by sputtering on the activated substrate;
A step of abutting the intermediate layer and the wiring material subjected to the activation treatment to perform a cold rolling treatment and laminating and bonding, and manufacturing a laminated material;
Etching the wiring material of the laminated material to produce a wiring pattern;
And a step of hot-pressing the laminated material to cause the wiring pattern to settle on the base material .

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