JP2007067189A - Wiring board and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wiring board capable of simply carrying out various wiring designs in a short time and at a low cost, responding to a request of a high density wiring, and carrying out a multilayer structure as needed. <P>SOLUTION: The wiring board is equipped with a substrate consisting of an insulating material, and a via and (or) a pierced hole formed in the substrate. The substrate consists of a lamination of at least two layers of insulating material layers which are formed by repeatedly printing substrate formation nature ink consisting of an insulating material; and the via and (or) the pierced hole are formed by eliminating cavity formation nature ink printed at forming sites of the via, and (or) the pierced hole after completing the lamination on the same plane as the insulating material layers whenever the insulating material layers are formed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wiring board, and more specifically, relates to a wiring board made of a printed laminate capable of realizing various wiring designs and a method of manufacturing such a wiring board using a printing method.

  A wiring board is a metal that is a good electrical conductor on an electrically insulating board, that is, a wiring pattern, an electrode, an external connection terminal, etc. formed of a conductive metal, and mounts semiconductor elements such as LSIs and other electronic components. Widely used for such purposes.

  FIG. 1 schematically shows a typical example of a wiring board currently used. In the illustrated wiring board, a substrate 101 serving as a core is formed by prepreg processing. After forming a through hole (through hole) 102 and a via 105, a through electrode 103 and a wiring pattern 104 are formed. Yes. In the case of this wiring board, the LSI chip 120 is mounted via the solder bumps 106.

  Although the wiring board as shown in the figure can be manufactured by various methods, generally, a process of drilling a through hole or a via using a laser or a drill in the prepared board is required. However, when drilling using a laser or the like, it is possible to drill only in the direction perpendicular to the substrate, for example, to realize high-density mounting, the electrode cannot be formed obliquely or in other patterns with respect to the substrate. There is a bug. Moreover, although the process of filling a through-hole and via | veer with a conductor metal is also required, this process is generally implemented by plating, and there is a problem that the plating operation takes a long time. Furthermore, in order to form a wiring pattern, a step of patterning the copper foil laminated on the prepreg is required. This step involves a series of processing processes including photoresist application, exposure, development, and copper foil etching. This is complicated, and it is difficult to form a fine wiring pattern.

As a specific example, Patent Document 1 describes a method of manufacturing a printed wiring board using a semi-additive method. According to this method, the printed wiring board has the following steps:
Forming inner layer conductor circuits on both upper and lower surfaces of the substrate;
Forming a plating resist and patterning (exposure and development);
Electrolytically plating the resist openings formed by patterning, and subsequently removing the plating resist,
Apply interlayer insulation resin to the entire surface,
Forming an opening for forming a via hole in an interlayer insulating resin (by laser or exposure and development);
Electroless plating on the entire surface,
Laminating and patterning dry film resist,
Performing electrolytic plating on the opening made in the dry film resist,
Remove the dry film resist and also remove the underlying electroless plating film,
Forming a solder resist layer on the outer conductor circuit;
Patterning the solder resist layer to form openings,
It can be manufactured by sequentially performing electroless nickel plating and electroless gold plating on the opening, and printing a solder paste on the gold plating layer to form solder bumps. However, this method requires many different processing steps as described above, requires a long processing time, and requires a specialized and expensive processing apparatus for each step.

JP 2000-188446 A (Claims, FIGS. 5 to 9)

  The object of the present invention is to realize various wiring designs easily, in a short time and at a low cost without using a conventionally used semi-additive method and other methods. An object of the present invention is to provide a wiring board that can cope with a multilayer structure as required.

  Another object of the present invention is to provide a method of manufacturing a wiring board that can easily manufacture the wiring board of the present invention as described above in a short time and with a high yield, and that does not require an expensive processing apparatus.

  These and other objects of the present invention will be readily understood from the following detailed description.

  As a result of diligent research to solve the above-mentioned problems, the present inventor switched the manufacturing process from a conventional photolithography-centric technique to a printing-centric technique, and formed a substrate in the form of a printed laminate. The present invention was completed by discovering that the problems could be solved simultaneously.

  The present invention is a wiring board provided with a substrate made of an insulating material, and vias and / or through holes formed in the substrate, and its constituent elements, for example, the substrate, vias, through holes, electrodes, The present invention provides a wiring board characterized in that wiring and the like are formed based on a printing method, and a method of manufacturing a wiring board using such a printing method.

In particular, the present invention is a wiring board comprising, in one surface, a substrate made of an insulating material, vias and / or through holes formed in the substrate,
The substrate is made of a laminate of at least two layers of insulating material formed by repeatedly printing a substrate-forming ink made of an insulating material, and the via and / or the through-hole has the insulating material. Each time the layer of the conductive material is formed, it is formed by removing the cavity-forming ink printed on the via and / or through-hole formation site in the same plane as the layer of the insulating material after completion of the laminate. It is in the wiring board characterized by being made.

In another aspect of the present invention, there is provided a method of manufacturing a wiring board including a substrate made of an insulating material, a via formed in the substrate, and / or a through hole.
The substrate is formed in the form of a laminate of at least two layers of insulating material by repeatedly printing substrate forming ink made of insulating material on a temporary support that is removed after completion of the wiring substrate. And forming the via and / or the through hole in the same plane as the layer of the insulating material and forming the via and / or the through hole in the same plane as the layer of the insulating material. The printed wiring board is formed by printing on a part and removing the printed matter from the laminated body after the laminated body is completed.

  The wiring board and the manufacturing method thereof according to the present invention can be advantageously implemented in various forms within the scope of the present invention. For example, the substrate-forming ink and the cavity-forming ink can be advantageously printed using an inkjet method.

  In the wiring board of the present invention, the vias and through holes formed in the wiring board may further have a conductor pattern (generally referred to as “wiring pattern layer” in the present invention) on the inner wall surface of those openings. Preferably, the wiring pattern layer may be formed using a conventional method such as plating, if necessary. However, a conductive ink containing conductive metal fine particles having a nano-sized particle size is printed. It is preferable to form by. Furthermore, as a printing method for forming such a wiring pattern layer, an inkjet method can be advantageously used.

  In addition, the present invention is an electronic device comprising the wiring board of the present invention and at least one type of electronic component mounted on the surface and / or inside the wiring board.

  As will be understood from the following detailed description, according to the present invention, various wiring designs can be realized simply, in a short time and at a low cost, and the demand for high-density wiring can be met. A wiring board capable of a multilayer structure can be provided.

  In addition, according to the present invention, it is not necessary to use a semi-additive method that has been conventionally used in the manufacture of wiring boards, so that problems caused by the use of photoresists and dry film resists can be solved. it can. For example, since the wiring board of the present invention can be formed by directly printing a wiring pattern, there is no problem of reduction in resolution and adhesion, and problems such as resist pattern collapse and resist residue are avoided. Can do.

  Furthermore, according to the present invention, in manufacturing the wiring board of the present invention as described above, the wiring board can be manufactured in a short time and with a high yield only by a simple processing process, and in that case, an expensive process is performed. There is an advantage that it is not necessary to use a device.

  Furthermore, according to the present invention, it is possible to provide a small and high-performance electronic device in which electronic components such as semiconductor elements are mounted on the wiring board of the present invention having various wiring designs.

  The wiring board and the manufacturing method thereof according to the present invention can be advantageously implemented in various forms. Hereinafter, the present invention will be described with reference to preferred embodiments thereof.

  The present invention resides in a wiring board comprising a substrate on which vias and through holes are formed and a wiring pattern layer formed on the upper surface, inside and / or lower surface thereof. Here, the configuration of the wiring board is not particularly limited as long as the requirements of the present invention are satisfied. In addition to the example illustrated and shown below, the wiring board (circuit board, printed circuit board, printed circuit board) is used. It is possible to have a configuration similar to that employed in a circuit board (also called a wiring board). The wiring board of the present invention is for mounting and supporting various functional components (hereinafter collectively referred to as “electronic components”). Typical examples of mountable electronic components are as follows. Although not limited to those listed, for example, semiconductor elements such as IC chips and LSI chips, capacitor elements (capacitors), reactor elements, inductor elements, and the like can be given.

  In the wiring board of the present invention, the main body is the board. The substrate can be formed from various insulating materials depending on the configuration of the wiring substrate. Insulating materials suitable for the practice of the present invention take into account that the substrate is formed by applying and curing the insulating material by printing and laminating two or more printed layers of insulating material. For example, a solder resist, a polyimide resin, an epoxy resin, a phenol resin, and the like are included. The solder resist is, for example, a thermosetting or ultraviolet curable resin, such as an epoxy resin or an acrylic resin. These insulating materials are preferably used in the form of ink (referred to as “substrate-forming ink” in the present invention). The substrate-forming ink can be changed depending on the printing method, but preferably has a composition and viscosity suitable for the selected printing method. In addition, various printing methods can be used for printing the substrate-forming ink, but it is versatile, the apparatus is simple and inexpensive, and a fine pattern can be drawn accurately and easily. In particular, the ink jet printing method can be advantageously used. Further, when printing is performed using the substrate-forming ink, the print pattern can be arbitrarily changed according to a desired wiring design.

  In the wiring board of the present invention, vias and through holes are formed in the board. These openings and other openings that may be present if necessary are characterized by being formed by a printing method in accordance with the present invention, using a laser or drill as in the conventional method. No drilling process is required.

  Openings such as vias and through-holes can be formed using various methods, but each time an insulating material layer is formed by printing, that is, each time a single insulating material layer is formed. Each time before or after printing of the substrate-forming ink or almost simultaneously with printing of the substrate-forming ink, it is selectively removed in a subsequent processing step in the same plane as the layer of insulating material (in other words, insulating The ink can be advantageously formed by printing an ink (referred to as “cavity-forming ink” in the present invention) capable of forming an island-like opening in the insulating material layer, leaving only the material layer). it can. The cavity-forming ink is preferably printed at the same thickness as the insulating material layer on the formation site of openings such as vias and through-holes, and the printing is repeated in the same manner as the printing of the insulating material layer. To do. Finally, when the printed matter derived from the cavity-forming ink is removed from the finally obtained laminate composed of two or more layers of insulating materials, openings such as vias and through holes are obtained. The printed material can be removed by various methods. For example, when the cavity-forming ink can be removed by etching, etching, for example, wet etching using an etching solution, can be advantageously used.

  Various types of cavity-forming inks can be used to form openings such as vias and through holes. The cavity-forming ink used here is particularly limited as long as it has a composition and viscosity suitable for printing and can be finally separated from the insulating material layer to form a desired opening. Is not to be done. Cavity-forming inks suitable for the practice of the present invention include, for example, etching resists, polyimide resins, epoxy resins, phenol resins and the like. The etching resist is, for example, a thermosetting or ultraviolet curable resin, such as an epoxy resin or an acrylic resin. In addition, various printing methods can be used for printing the cavity-forming ink, but it is versatile, the device is simple and inexpensive, and a fine pattern can be drawn accurately and easily. In particular, the ink jet printing method can be advantageously used. If the inkjet printing method is used, printing with the substrate-forming ink and the cavity-forming ink can be performed continuously and continuously according to the desired printing pattern by using a printer with a plurality of heads. This is because it is possible to form one layer easily and in a short time, and immediately shift to formation of the next layer. The ink used for inkjet printing is usually a solution prepared by dissolving a resin component in a solvent together with other components, but if desired, it may be a melt obtained by melting the resin component. Good. Further, when printing is performed using the cavity-forming ink, it is preferable to arbitrarily change the print pattern according to a desired wiring design.

  In the wiring board of the present invention, the board further includes a wiring pattern layer. Examples of the formation site of the wiring pattern layer include an inner wall surface of an opening such as a via and a through hole, an upper surface and a lower surface of the substrate, and the inside of the substrate. That is, when used in the present invention, the term “wiring pattern layer” is used in a broad sense, and the terms commonly used in this technical field are “wiring circuit”, “wiring layer”, “wiring pattern”, “ In addition to “electrode”, “through electrode”, “filled via”, “external connection terminal” and the like are also included. The wiring pattern layer is not particularly limited as long as desired conductive characteristics can be obtained. For example, any conductive metal such as gold, silver, copper, nickel, aluminum, chromium, palladium, indium, tin, etc. Alternatively, it can be advantageously formed from the alloy. If necessary, these wiring pattern layers may be formed from indium tin oxide (ITO).

  When forming a wiring pattern layer on the inner wall surface of an opening such as a via or a through-hole or in other places, it is preferably formed by a printing method, particularly including fine particles of a conductive metal having a nano-size particle size It is preferably formed by printing a conductive ink (so-called nano ink). Further, when the wiring pattern layer is formed by a printing method using nano ink, it is recommended to adopt an inkjet method as a printing method in accordance with the formation of the substrate and the opening as described above. The ink jet method is versatile, has a simple and inexpensive device, can accurately and easily draw a fine pattern, and can easily fill ink in an opening portion. This is because the same printer can be used in common with the formation of the opening.

  Here, the nano ink that can be used in the practice of the present invention will be described. As described above, the nano ink is a conductive liquid containing fine particles of a conductive metal having a nano-sized particle diameter. Examples of the conductive metal are not limited to those listed below, but include gold, silver, and the like. , Copper, nickel, palladium, indium, ITO and the like. The fine particles derived from these metal species usually have an average particle diameter of about 2 to 200 nm. These metal fine particles are used to prepare inks, for example, dispersants (eg, alkylamines, carboxylic acid amides, aminocarboxylates, etc.) and solvents (eg, organic solvents such as toluene, xylene, tetradecane, alcohols, water). Etc.). The concentration of the metal fine particles in the nano ink can be varied within a wide range, but is usually about 60% by weight or less, and preferably about 5 to 55% by weight. The viscosity of the nano ink is usually about 5 to 20 cps.

  The wiring pattern layer is preferably formed by a printing method as described above. However, if necessary, it can be formed into a thick film by a simple method. Therefore, a plating method, preferably an electrolytic plating method may be used in combination. If so, a combination of electroless plating and electrolytic plating may be used. If acceptable, the wiring pattern layer may be formed using a conventional thin film forming method such as sputtering or vapor deposition.

Although the wiring board according to the present invention can be manufactured using various methods, it is advantageous to manufacture the wiring board by including the following steps.
(1) Forming a laminate of at least two layers of insulating material by repeatedly printing a substrate-forming ink made of an insulating material on a temporary support removed after completion of the wiring board. Forming with,
(2) The via and / or the through hole are the same as the insulating material layer before or after printing the substrate forming ink or almost simultaneously with the printing of the substrate forming ink each time the insulating material layer is formed. In a plane, printing the cavity-forming ink on the via and / or through-hole formation site, and removing the printed matter from the laminate after completion of the laminate consisting of at least two layers of insulating material And (3) wiring pattern layer by printing conductive ink (nano ink) containing fine particles of conductive metal having nano-size particle diameter on the inner wall surface of via and / or through-hole Forming.
In these processing steps, it is preferable that printing of the substrate-forming ink, the cavity-forming ink, and the conductive ink is commonly performed using the inkjet method as described above.

More specifically, for example, the method for manufacturing a wiring board of the present invention can be advantageously carried out as follows.
1) Prepare a temporary support to be removed after the wiring board is completed. As the support used here, an optimum support can be selected according to a method (for example, etching, grinding, etc.) used for removing the support from the substrate. For example, a copper plate, a glass plate, a polyimide resin plate, or the like can be advantageously used because it is inexpensive and easy to process.
2) On the prepared temporary support, a first substrate layer is formed with an insulating ink (substrate forming ink such as solder resist, polyimide resin, etc.). It is preferable to apply the insulating ink in a predetermined pattern using an ink jet method.
3) At the stage of forming the first substrate layer, before, during or after applying the insulating ink, a portion where an opening such as a via or a through-hole is planned to be formed (do not apply the insulating ink) In the region, a first cavity layer is formed with an etchable ink (cavity-forming ink, such as an etching resist). Similarly to the first substrate layer, the first cavity layer is preferably applied using an ink jet method. In addition, it is preferable that the etchable ink can be applied and cured simultaneously with the insulating ink, that is, under the same conditions, in order to simplify the processing.
4) The first substrate layer and the first cavity layer as applied are cured simultaneously. For example, when two layers are ultraviolet curable, they are cured by irradiating ultraviolet rays at once. A first substrate layer having a predetermined thickness incorporating the first cavity layer is obtained.
5) By repeating the above-described steps 2) to 4) a predetermined number of times (n times), a laminate (substrate precursor) composed of the first to nth substrate layers is formed.
6) Only the first to nth cavity layers are selectively removed from the obtained laminate. Since the cavity-forming ink used for forming the cavity layer can be etched, only the cavity layer is completely removed without leaving a residue by, for example, wet etching using an etching solution, and the desired opening portion is formed. (Vias, through holes, etc.) can be obtained.
In addition, although the obtained opening part is normally used for formation of a wiring, a penetration electrode, etc., the shape and pattern of the opening part can be arbitrarily changed according to the adjustment of the print pattern, and is therefore arranged obliquely. Wiring and electrodes can be easily formed.
7) The metal nano ink is filled in the opening formed in the laminate including the first to nth substrate layers. The filling of the metal nano ink can be preferably performed by ink jet printing or dip coating, but may be performed by filling of a conductive paste or metal plating if necessary.
When filling the opening with metal nano ink, the metal nano ink may be heated to fill the opening and then the metal component may be heated to sinter the metal component. Filling and heating may be performed in a plurality of times. That is, the process of filling the opening with the metal nano ink and heating can be repeated until the thickness of the metal layer in the opening reaches a desired thickness. If the metal nano ink is formed by dip coating, extra metal adheres to the surface of the substrate, and it is recommended that the metal be removed by, for example, a chemical mechanical polishing method (CMP method).
8) Through a series of processing steps as described above, a wiring board (for example, a wiring board made of a cured laminate of solder resist) on which wirings, vias, through holes, and the like are formed is obtained. On this wiring board, an LSI chip and other electronic components can be mounted according to a conventional method, for example, via solder bumps.

  In the manufacturing method described above, the laminate (substrate precursor) is formed by repeating steps 2) to 4), but if necessary, the formation of the laminate is interrupted halfway and formed by a curing process. Alternatively, an electronic component such as a semiconductor chip or a capacitor may be formed on the first substrate. Subsequently, steps 2) to 4) are repeated again to form the remaining laminated body, and finally, a wiring board incorporating an electronic component can be formed.

  The present invention further resides in an electronic device comprising the wiring board of the present invention and at least one electronic component mounted on the wiring board. Here, the electronic components to be mounted on the wiring board are not limited to those listed below. For example, as described above, semiconductor elements such as IC chips and LSI chips, and capacitor elements (capacitors) , Reactor elements, inductor elements, and the like. Of course, these electronic components may be mounted on the surface of the wiring board, may be mounted inside the wiring board, or may be mounted in combination with the surface and inside. These electronic components may be used alone or in combination of two or more depending on the desired function. Furthermore, the respective electronic components can be electrically connected to each other by a flip chip method, a wire bonding method, or the like, or can be electrically connected to a wiring pattern layer or an external connection terminal of the wiring board.

  Subsequently, several embodiments of the present invention will be described with reference to the accompanying drawings. Needless to say, the present invention is not limited to these examples.

  FIG. 2 is a cross-sectional view showing an example of a wiring board according to the present invention. The wiring board 10 includes a substrate 1 made of an insulating material and a through hole filled with a conductive metal, that is, a through electrode 1B. In this wiring substrate 10, the substrate 1 is formed by repeatedly printing a substrate-forming ink made of an insulating material, that is, an insulating ink 1A such as, for example, a solder resist. It consists of a laminated body of six substrate layers, that is, the first substrate layer 1 (1) to the sixth substrate layer 1 (6). Further, the through electrode 1B is formed by printing a removable cavity-forming ink on a through hole forming portion, further removing it to form a through hole, filling the through hole with metal nano ink, and curing the ink. It is formed by. The metal nano ink is, for example, a copper nano ink. In the case of this example, every time the first substrate layer 1 (1) to the sixth substrate layer 1 (6) are formed, a portion such as an etching resist is formed in the through hole forming portion in the same plane as those layers. After printing the cavity-forming ink, forming the first to sixth cavity layers simultaneously with the formation of the first to sixth substrate layers, and curing the obtained laminate, the first to sixth cavities are formed. Through-holes were formed by selectively removing the layer by etching. In the case of this example, since the through hole is formed by combining the oblique through electrode 1B, the through hole formed obliquely to the through hole formed perpendicular to the substrate 1 as understood from the figure. Two types of holes were prepared. The through holes formed obliquely indicate that the wiring pattern can be formed by any design according to the present invention.

  The wiring board 10 has an electronic component (in this example, an LSI chip) 20 mounted on the upper surface thereof. The LSI chip 20 is mounted via solder bumps (for example, Pb / Sn) 21 at the electrodes 11 formed in advance on the wiring board 10. The electrode 11 may be formed from the metal nano ink simultaneously with the formation of the through electrode 1B, or may be formed in another process, for example, by copper plating. Moreover, the wiring board 10 has an electrode 12 on its lower surface. The electrode 12 may be formed from the metal nano ink simultaneously with the formation of the through electrode 1B, or may be formed by another process, for example, by copper plating.

  FIG. 3 is a sectional view showing another example of the wiring board according to the present invention. The wiring board 10 includes a substrate 1 made of an insulating material and a through hole filled with a conductive metal, that is, a through electrode 1B. In this wiring board 10, the board 1 is formed by repeatedly printing a board-forming ink made of an insulating material, that is, an insulating ink 1A, as in the example described above with reference to FIG. Although not shown, it is composed of a laminate of a plurality of substrate layers. Further, the through electrode 1B is formed by printing a removable cavity-forming ink on a through hole forming portion, further removing it to form a through hole, filling the through hole with metal nano ink, and curing the ink. It is formed by. Also in this example, each time a substrate layer is formed, a cavity-forming ink such as an etching resist is printed on the through-hole formation portion in the same plane as that layer, and each substrate layer is formed. At the same time, a cavity layer corresponding to the substrate layer is formed, the obtained laminate is cured, and then only the cavity layer is selectively removed by etching to form a through hole. Further, in the case of this example, the through hole is not formed perpendicular to the substrate 1, but according to the desired wiring pattern, one through hole is provided with a step and the other through hole is Each is formed in a spiral shape. That is, by adopting the method as in this example, the shape of the wiring and the through electrode can be arbitrarily changed, and the degree of freedom of design is greatly increased.

  The wiring board 10 has an electronic component (in this example, an LSI chip) 20 mounted on the upper surface thereof. The LSI chip 20 is mounted via solder bumps (for example, Pb / Sn) 21 at the electrodes 11 formed in advance on the wiring board 10. The electrode 11 may be formed from the metal nano ink simultaneously with the formation of the through electrode 1B, or may be formed by copper plating or the like in another process. Moreover, the wiring board 10 has an electrode 12 on its lower surface. The electrode 12 may be formed from the metal nano ink simultaneously with the formation of the through electrode 1B, or may be formed by copper plating or the like in another process. Further, the illustrated electrode 12 is also provided with a solder bump (for example, Pb / Sn) 13.

  FIG. 4 is a sectional view showing still another example of the wiring board according to the present invention. The wiring board 10 includes a substrate 1 made of an insulating material and a through hole filled with a conductive metal, that is, a through electrode 1B. In this wiring board 10, the board 1 is formed by repeatedly printing a board-forming ink made of an insulating material, that is, an insulating ink 1A, as in the example described above with reference to FIG. Although not shown, it is composed of a laminate of a plurality of substrate layers. Further, the through electrode 1B is formed by printing a removable cavity-forming ink on a through hole forming portion, further removing it to form a through hole, filling the through hole with metal nano ink, and curing the ink. It is formed by. Also in this example, each time a substrate layer is formed, a cavity-forming ink such as an etching resist is printed on the through-hole formation portion in the same plane as that layer, and each substrate layer is formed. At the same time, a cavity layer corresponding to the substrate layer is formed, the obtained laminate is cured, and then only the cavity layer is selectively removed by etching to form a through hole. However, in this example, an electronic component (in this example, a chip capacitor) 30 is built in the wiring board 10. In the case of this example, the chip capacitor 30 can be easily incorporated into a desired position of the wiring substrate 10 by forming the substrate 1 in two stages. That is, a first substrate is manufactured, and the chip capacitor 30 is mounted on the substrate. The inner layer wiring 1C can be formed simultaneously with the formation of the through wiring 1B of the first substrate. Next, a second substrate is manufactured on the first substrate after mounting the chip capacitor 30 by a method similar to the manufacturing of the first substrate. Although one chip capacitor 30 is built in the figure, the type and number of built-in electronic components are not limited.

  The wiring board 10 has an electronic component (in this example, an LSI chip) 20 mounted on the upper surface thereof. The LSI chip 20 is mounted via solder bumps (for example, Pb / Sn) 21 at the electrodes 11 formed in advance on the wiring board 10. The electrode 11 may be formed from the metal nano ink simultaneously with the formation of the through electrode 1B, or may be formed by copper plating or the like in another process. Moreover, the wiring board 10 has an electrode 12 on its lower surface. The electrode 12 may be formed from the metal nano ink simultaneously with the formation of the through electrode 1B, or may be formed by copper plating or the like in another process. Further, the illustrated electrode 12 is also provided with a solder bump (for example, Pb / Sn) 13.

  More specifically, the wiring board 10 of the type shown in FIG. 2 can be advantageously manufactured by a technique as shown in order in FIGS. 5A is a cross-sectional view taken along the line AA in FIG. 5B, and FIG. 6A is taken along the line AA in FIG. 6B. FIG.

  First, as shown in FIG. 5A, a copper plate 31 is prepared as a temporary support that is used as a base during the production of a wiring board and is removed after the wiring board is completed. The size of the copper plate 31 can be arbitrarily changed. For example, the size of the copper plate 31 may be approximately the same size as the area of one wiring board, or it is intended to manufacture a plurality of wiring boards at once. For example, it may be approximately the same size as the total area of those wiring boards.

  Next, the first substrate layer 1 (1) is formed on the prepared copper plate 31. In the case of this example, the first substrate layer 1 (1) was formed by printing an insulating ink (solder resist) 1a with an ink jet printer in a predetermined pattern. Although only one head 32 of the ink jet printer is shown in the figure, in actuality, printing is completed in a short time and, as will be described below, the cavity-forming ink is also printed almost simultaneously in parallel. Therefore, it is advantageous to use two or more inkjet heads.

  In the case of this example, the cavity forming ink (etching resist) that can be etched is printed simultaneously with the printing of the solder resist using the two inkjet heads 32 to form the first cavity layer 1b. As can be understood from the drawing, the first cavity layer 1b is formed in a portion where a through hole is to be formed (a region where the solder resist is not printed). As described above, it is preferable to print the etching resist almost simultaneously with the printing of the solder resist. However, if necessary, the solder resist is printed in the step of forming the first substrate layer 1 (1). It may be carried out before or after.

  After the printing of the solder resist and the etching resist is completed, these resists that are still uncured are simultaneously cured. In the case of this example, since both resists were ultraviolet curable, both were cured at once by irradiating a predetermined amount of ultraviolet rays. As shown in the figure, a first substrate layer 1 (1) made of a solder resist 1a, in which the first cavity layer 1b is incorporated in the through hole forming portion, is obtained. The thickness of the first substrate layer 1 (1) is about 3 to 10 μm.

  After the formation of the first substrate layer 1 (1) is completed, the solder resist and the etching resist are printed according to the same method as described above except for the difference in changing the printing pattern of the solder resist and the etching resist, Third,... Substrate layers are sequentially formed. In the case of this example, as illustrated, a total of six substrate layers, that is, a laminate of the first substrate layer 1 (1) to the sixth substrate layer 1 (6) was formed. In addition, since this laminated body has not arrived at the form of the final board | substrate, in this invention, it calls a "substrate precursor" especially.

  Next, the etching resist constituting the first to sixth cavity layers 1b is selectively removed from the obtained substrate precursor. In this example, an etching solution corresponding to the etching resist was prepared, and the etching resist was removed by wet etching. As shown in FIG. 7, the through hole 1C was obtained without leaving a resist residue.

  Subsequently, as shown in FIG. 8, the metal nano-ink is filled in the opening 1C of the substrate precursor. In this example, copper nano ink was used as the metal nano ink, and this ink was poured into the opening 1 </ b> C by an ink jet printer having two heads 33. In this example, filling and heating (copper sintering) of the copper nano ink in the opening were performed in a plurality of times, and the metal layer 1B was filled in the opening 1C with a desired thickness.

  Through a series of processing steps as described above, as shown in FIG. 9, a wiring board (wiring board made of a cured layer of solder resist) 10 having a laminated structure in which through electrodes 1B are formed was obtained. . As described above with reference to FIG. 2, an LSI chip and other electronic components can be mounted on the wiring board 10.

  The chip capacitor built-in type wiring substrate 10 shown in FIG. 4 can also be manufactured by a method similar to the method of manufacturing the wiring substrate 10 of FIG. Hereinafter, a method of manufacturing the chip capacitor built-in wiring board 10 will be described with reference to FIG.

  First, as shown in FIG. 10A, a first substrate layer 1 (1) and a second substrate layer 1 (2) are sequentially formed on a copper plate 31. In the case of this example, an insulating ink (solder resist) 1a was printed by an ink jet printer to form these substrate layers. Simultaneously with the formation of these substrate layers, an etchable cavity-forming ink (etching resist) was printed with an inkjet printer to form the first and second cavity layers 1b. In the formation of the second cavity layer, the printing pattern of the etching resist was changed as shown in the drawing in order to form the inner layer wiring simultaneously with the through electrode. Further, in the formation of each substrate layer, after the printing of the solder resist and the etching resist was completed, these uncured resists were cured by ultraviolet irradiation. As shown in the figure, a first substrate layer 1 (1) made of a solder resist 1a in which a first cavity layer 1b is incorporated in a through hole forming portion, and the first cavity layer 1b is formed in a through hole forming portion and an inner layer wiring. A first substrate precursor provided with the second substrate layer 1 (2) made of the solder resist 1a incorporated in the formation site was obtained.

  Next, the etching resist constituting the first and second cavity layers 1b is selectively removed from the obtained first substrate precursor. In this example, the etching resist was removed by wet etching. After the openings are formed in the through hole forming portion and the inner layer wiring forming portion of the first substrate precursor in this way, as shown in FIG. 10 (B), a metal is formed in the opening of the first substrate precursor. Fill with nano ink. In this example, copper nano ink was used as the metal nano ink, and this ink was poured into the opening by an ink jet printer (not shown). Thereafter, the copper nano ink was heated to sinter copper in the ink.

  Subsequently, as shown in FIG. 10C, a chip capacitor 30 was mounted on the first substrate precursor via Au bumps (not shown). The Au bump is connected to the through electrode (copper) 1B through an inner layer wiring (copper) derived from copper nano ink.

  After forming the first substrate precursor on which the chip capacitor 30 is mounted as described above, as shown in FIG. 10C, the third substrate layer 1 (3) to the sixth substrate layer 1 ( A second substrate precursor comprising the laminate of 6) is formed. The formation of the second substrate precursor can be performed by repeating the steps of printing and curing the solder resist and the etching resist in the same manner as the formation of the first substrate precursor described above.

  After the second substrate precursor is produced as described above, the etching resist constituting the third to sixth cavity layers 1b is selectively removed. Next, as in the case of the first substrate precursor, copper nano ink is poured into the opening formed in the second substrate precursor with an ink jet printer, and further heated (copper sintering). As shown in FIG. 10E, a wiring board (wiring board made of a hardened layer of solder resist) 10 having a laminated structure in which the through electrode 1B is formed and the chip capacitor 30 is embedded is obtained.

  Subsequently, as shown in FIG. 10E, the LSI chip 20 is mounted on the wiring substrate 1 in which the chip capacitor 30 is built. In the case of this example, the LSI chip 20 is mounted via the solder bump (Pb / Sn) 21. Finally, when the unnecessary temporary support (copper plate) 31 was removed by etching, a device having a target structure was obtained as shown in FIG. 10 (F).

It is sectional drawing which showed an example of the conventional wiring board. It is sectional drawing which showed one preferable form of the wiring board by this invention. It is sectional drawing which showed another preferable form of the wiring board by this invention. It is sectional drawing which showed another preferable form of the wiring board by this invention. FIG. 3 is a cross-sectional view sequentially showing a manufacturing process (part 1) of the wiring board of FIG. 2; FIG. 3 is a cross-sectional view illustrating a manufacturing process (part 2) of the wiring board of FIG. 2 in order. FIG. 3 is a cross-sectional view illustrating a manufacturing process (part 3) of the wiring board of FIG. 2 in order. FIG. 3 is a cross-sectional view illustrating a manufacturing process (part 4) of the wiring board of FIG. 2 in order. FIG. 3 is a cross-sectional view illustrating a manufacturing process (part 5) of the wiring board of FIG. 2 in order. FIG. 5 is a cross-sectional view illustrating the manufacturing process of the wiring board of FIG. 4 in order.

Explanation of symbols

1 Substrate 10 Wiring Board 20 LSI Chip 30 Chip Capacitor 31 Support 32 Inkjet Head 33 Inkjet Head

Claims (12)

A wiring board comprising a substrate made of an insulating material, and vias and / or through holes formed in the substrate,
The substrate is made of a laminate of at least two layers of insulating material formed by repeatedly printing a substrate-forming ink made of an insulating material, and the via and / or the through-hole has the insulating material. Each time the layer of the conductive material is formed, it is formed by removing the cavity-forming ink printed on the via and / or through-hole formation site in the same plane as the layer of the insulating material after completion of the laminate. A wiring board characterized by being made.   The wiring board according to claim 1, wherein the substrate-forming ink contains a solder resist or an insulating resin.   The wiring board according to claim 1, wherein the cavity-forming ink contains an etching resist.   The wiring according to claim 1, wherein the substrate-forming ink and the cavity-forming ink are printed with different print patterns according to a desired wiring design. substrate.   The wiring board according to claim 1, wherein the substrate-forming ink and the cavity-forming ink are each printed using an inkjet method.   The via and / or the through-hole further has a wiring pattern layer formed by printing a conductive ink containing at least a conductive metal fine particle having a nano-size particle diameter on the inner wall surface thereof. The wiring board according to claim 1, wherein:   The wiring board according to claim 6, wherein the conductive ink is printed using an inkjet method.   The wiring board according to claim 1, further comprising a wiring pattern layer on at least one surface and / or inside thereof. A method of manufacturing a wiring board comprising a substrate made of an insulating material, and vias and / or through holes formed in the substrate,
The substrate is formed in the form of a laminate of at least two layers of insulating material by repeatedly printing substrate forming ink made of insulating material on a temporary support that is removed after completion of the wiring substrate. And forming the via and / or the through hole in the same plane as the layer of the insulating material and forming the via and / or the through hole in the same plane as the layer of the insulating material. A method of manufacturing a wiring board, comprising: printing on a part and forming the printed material by removing the printed material from the laminated body after the laminated body is completed.   The method for manufacturing a wiring board according to claim 9, wherein the substrate-forming ink and the cavity-forming ink are each printed using an inkjet method.   The method further includes the step of forming a wiring pattern layer by printing conductive ink containing conductive metal fine particles having a nano-size particle size on the inner wall surface of the via and / or the through-hole. The manufacturing method of the wiring board of Claim 9 or 10.   The method for manufacturing a wiring board according to claim 11, wherein the conductive ink is printed using an inkjet method.

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