JP2006310543A - Wiring board and its production process, wiring board with semiconductor circuit element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wiring board having high connection reliability with high production yield. <P>SOLUTION: The wiring board 12 comprises a flexible board 51 and a substantially planar capacitor 131. The capacitor 131 has a plurality of connection terminals 41 arranged in array on the major surface 23 of the capacitor. The major surface 23 of the capacitor 131 is bonded to the first major surface 53 side of the flexible board 51. The flexible board 51 has a plurality of surface terminal portions 56 in a region on the second major surface 52 thereof corresponding to the portion where the capacitor 131 exists. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wiring board including a flexible substrate and a capacitor, a manufacturing method thereof, and a wiring board with a semiconductor circuit element including the wiring board and a semiconductor circuit element.

In recent years, in the field of electrical products such as personal computers and digital home appliances, and in the field of automobiles, the miniaturization, high functionality, and high added value of products have been increasing. Accordingly, miniaturization and high density of the mother board, which is an important electrical component in this type of product, are desired, and miniaturization of various components mounted on the motherboard is also desired. As what realizes miniaturization of various parts, for example, a so-called system-in-package (SIP) in which a plurality of LSIs are sealed and systemized can be cited. In such a package, a semiconductor circuit element such as an IC chip is mounted on a wiring board, for example (see, for example, Patent Document 1).
Japanese Unexamined Patent Publication No. 2004-128418 (FIGS. 12, 13, etc.)

  By the way, with the recent increase in the frequency of products, a large number of chip capacitors 122 are mounted on the flexible substrate 121 constituting the wiring substrate in addition to the IC chip 120 (see FIG. 13). Further, the chip capacitors 122 are densely arranged to save space.

  However, normally, the chip capacitors 122 are not arranged uniformly on the flexible substrate 121, but are often arranged densely at specific locations. For this reason, the difficulty of bending of the flexible substrate 121 is greatly different between the mounting region and the non-mounting region of the chip capacitor 122. Therefore, when some stress is applied to the flexible substrate 121, the stress is likely to be concentrated on the non-mounting region where the flexible substrate 121 is easily bent. As a result, the flexible substrate 121 is likely to be deformed and uneven, and the coplanarity of the main surface is lowered. Therefore, even if the IC chip 120 is mounted on the surface opposite to the chip capacitor mounting surface, poor connection is likely to occur between the flexible substrate 121 and the IC chip 120, and high connection reliability cannot be obtained.

  The present invention has been made in view of the above problems, and a first object thereof is to provide a wiring board having high connection reliability and a wiring board with a semiconductor circuit element. A second object is to provide a method of manufacturing a wiring board with a low probability of being a defective product and a high yield.

  And as means (means 1) for solving the above-mentioned problems, a flexible substrate having a first substrate main surface and a second substrate main surface, a capacitor main surface, and an array on the capacitor main surface are provided. A substantially flat capacitor having a plurality of connection terminals arranged, the capacitor main surface being bonded to the first substrate main surface side, wherein the flexible substrate has the capacitor on the second substrate main surface. There is a wiring board characterized by having a plurality of surface terminal portions in a region corresponding to the existence portion.

  Therefore, according to the wiring substrate of the means 1, the flexible substrate is reinforced by adhering the substantially flat capacitor. Moreover, the plurality of connection terminals are arranged in an array on the capacitor main surface, that is, evenly distributed on the capacitor main surface, and are reinforced by being connected to the conductor portion of the flexible substrate. As a result, the strength of the flexible substrate is uniform in a region corresponding to the portion where the capacitor exists. Therefore, the flexible substrate is deformed and is less likely to cause unevenness, so that the coplanarity in the region is increased. As a result, connection failure at the surface terminal portion of the region is less likely to occur, and high connection reliability can be obtained.

  The flexible substrate according to the means 1 may be present only in one layer, or may be present in two or more layers (multilayer). When there is only one layer of the flexible substrate, the semiconductor circuit element that can be connected to the surface terminal portion is more directly supported by the capacitor, so that the semiconductor circuit element is more reliably fixed and the connection reliability is higher. On the other hand, in the case where there are multiple flexible substrates, it is possible to configure more circuits and the like, as compared with the case where the flexible substrate is not multilayer (only one layer), and the added value can be increased.

  The material for forming the flexible substrate can be appropriately selected from non-thermoplastic resins and the like in consideration of cost, workability, insulation, flexibility, mechanical strength, and the like. With such a resin substrate, a fine wiring layer can be formed relatively easily and accurately, and a surface terminal portion capable of connecting an element having a very large number of terminals can be easily formed. Can do. That is, such a substrate is suitable as a substrate for mounting a semiconductor circuit element.

  Moreover, it is preferable that the material which forms a flexible substrate has heat resistance. Specifically, the resin material preferably has a glass transition temperature (Tg) of 220 ° C. or higher. The resin material preferably has a heat resistance of, for example, 260 ° C. and a level of 10 minutes or more, and more preferably a heat resistance of 300 ° C. and a level of 10 minutes or more. Further, the resin material preferably has a solder heat resistance of 250 ° C. and a level of 20 seconds or more, and particularly preferably has a solder heat resistance of 260 ° C. and a level of 120 seconds or more. It is more preferable that the properties are 300 ° C. and 180 seconds or more. This is because even if the wiring board is formed by thermocompression bonding, for example, deformation of the flexible board can be prevented.

  Preferable examples of the non-thermoplastic resin that forms the insulating portion of the flexible substrate include polyimide resin, polyamideimide resin, and polyamide resin. In addition, composite materials of these resins and glass fibers (glass woven fabric or glass nonwoven fabric) or organic fibers such as polyamide fibers may be used.

  The capacitor has a function of increasing the coplanarity of the second main surface of the flexible substrate, and is a component mainly composed of a material having higher mechanical strength than the flexible substrate. For this reason, the Young's modulus of the capacitor is preferably set to 0.1 GPa or more, for example, and more preferably set to 1 GPa or more and 500 GPa or less. The thermal expansion coefficient in the planar direction of the capacitor is preferably set lower than the thermal expansion coefficient in the planar direction of the flexible substrate, and is preferably set to, for example, 5 ppm / ° C. or more and 13 ppm / ° C. or less. When the thermal expansion coefficient is 13 ppm / ° C. or less, the capacitor is difficult to be plastically deformed by heat, and the flexible substrate is difficult to bend. For this reason, the coplanarity of the area | region corresponding to the presence part of a capacitor in the board | substrate 2nd main surface can be maintained. Further, when the semiconductor circuit element that can be connected to the surface terminal portion is formed of silicon (coefficient of thermal expansion is around 3 ppm / ° C.), the coefficient of thermal expansion in the planar direction of the capacitor and the coefficient of thermal expansion in the planar direction of the semiconductor circuit element Is preferably set to 3 ppm / ° C. or more and 8 ppm / ° C. or less, for example.

  The capacitor is preferably a ceramic capacitor. In this way, the capacitor can function as a heat sink. Further, since ceramic is excellent in rigidity, the mechanical strength of the capacitor can be increased and the flexible substrate can be reliably reinforced. In addition, since ceramic materials generally have a lower coefficient of thermal expansion than metals and resins, they are suitable as capacitor materials. Specific examples of the ceramic include, but are not limited to, low-temperature fired materials such as barium titanate, alumina, aluminum nitride, beryllia, glass ceramic, and crystallized glass.

  The capacitor may be a component involved in improving the operability of the semiconductor circuit element that can be connected to the surface terminal portion, for example, a component for stabilizing the power to be supplied to the semiconductor circuit element. Is preferred.

  The area of the capacitor main surface of the capacitor is preferably the same as the area of the element mounting area (area where the surface terminal portion is present) or slightly larger than the area of the area where the element mounting area is present. If the area of the capacitor main surface is smaller than the area of the element mounting area, it is difficult to reliably reinforce the element mounting area of the flexible substrate. On the other hand, if the area of the capacitor main surface is too large (for example, 10 times or more) compared to the area of the element mounting region, the entire flexible substrate is reinforced by adhesion of the capacitor, so that the flexibility of the flexible substrate is easily lost.

  Further, the thickness of the capacitor is preferably set to, for example, 50 μm or more and 200 μm or less. By setting the thickness of the capacitor to 50 μm or more, high mechanical strength of the capacitor can be secured and the flexible substrate can be reliably supported. On the other hand, by setting the thickness of the capacitor to 200 μm or less, it is possible to prevent the wiring board from being enlarged in the thickness direction (Z direction).

  The plurality of connection terminals on the capacitor main surface are arranged in an array (lattice shape). Specifically, when the capacitor main surface has a rectangular shape, for example, the capacitor main surfaces are equally spaced along the vertical and horizontal directions of the capacitor main surface. Is arranged. The plurality of connection terminals may be arranged in an array on a part of the capacitor main surface, or may be arranged in an array over the entire capacitor main surface. It is preferable to arrange | position over. In this way, the flexible substrate is reinforced not only in the region corresponding to the portion where the capacitor exists, but also outside the region, so that the coplanarity of the flexible substrate can be increased over a wider range.

  The number of connection terminals on the capacitor main surface basically depends on the number of via conductors included in the capacitor, and is set to, for example, 100 or more, preferably 500 or more. If the number of connection terminals is increased, the area of the region supported by the connection terminals on the flexible substrate is increased. As a result, the flexible substrate is less likely to be uneven, and the coplanarity of the main surface is increased. In the plurality of connection terminals, the center-to-center distance between adjacent connection terminals (that is, the connection terminal pitch) basically depends on the pitch of the plurality of via conductors included in the capacitor, and is, for example, 400 μm or less (excluding 0 μm). ), Preferably 300 μm or less. If the connection terminal pitch is reduced, the number of connection terminals to be arranged is increased, so that the area of the region supported by the connection terminals in the flexible substrate is increased. As a result, the flexible substrate is less likely to be uneven, and the coplanarity of the main surface is increased. Further, the maximum diameter of the connection terminal is preferably set slightly smaller than the connection terminal pitch, specifically 300 μm or more (however, excluding 0 μm), preferably 200 μm or more. If the maximum diameter of the connection terminals is made larger than the connection terminal pitch, the gap between the adjacent connection terminals is reduced, so that the area of the region supported by the connection terminals on the flexible substrate is increased. As a result, the flexible substrate is less likely to be uneven, and the coplanarity of the main surface is increased.

  The capacitor includes a capacitor back surface, a plurality of connection terminals arranged in an array on the capacitor back surface, a plurality of connection terminals on the capacitor main surface, and a plurality of connection terminals on the capacitor back surface. A via array type capacitor having a plurality of via conductors to be conducted is preferable. In this way, the degree of freedom of wiring increases compared to the case where a plurality of connection terminals are provided only on the capacitor main surface.

  When the wiring board is formed by thermocompression bonding, the flexible board and the capacitor are adhesively bonded by heating, and the sheet first main surface that adheres to the capacitor main surface and the substrate first main surface of the flexible substrate It is preferable to adhere through an adhesive sheet having a second sheet main surface to be bonded to the top and a plurality of conductive pillars conducting between the first sheet main surface and the second sheet main surface. In this way, when the connection terminal of the capacitor main surface comes into contact with the sheet first main surface, the sheet first main surface can follow the uneven shape on the capacitor main surface side. Unevenness is less likely to occur on the second main surface. Therefore, the adhesiveness is increased and the coplanarity of the sheet second main surface is increased. Therefore, the coplanarity of the region corresponding to the portion where the capacitor exists on the second main surface of the flexible substrate becomes higher.

  Furthermore, when the capacitor and the flexible substrate are bonded via the adhesive sheet, at least a part of the plurality of connection terminals and the plurality of surface terminal portions are interposed via the plurality of conductor columns in the adhesive sheet. Are preferably electrically connected to each other. In this way, the length of the wiring connecting the capacitor and the surface terminal portion is shortened, so that the speed of the signal between the capacitor and the surface terminal portion can be increased. Furthermore, it is possible to stabilize the power supply by reducing the inductance between the capacitor and the surface terminal portion.

  Note that only one layer of the adhesive sheet may exist between the flexible substrate and the capacitor, or two or more layers (multilayers) may exist. In addition, when the flexible substrate is mainly composed of a non-thermoplastic resin and the adhesive sheet is mainly composed of a thermoplastic resin, it is preferable that only one layer of the adhesive sheet exists. In this way, compared to the case where there are two or more adhesive sheets, the adhesive sheet is less likely to be plastically deformed during thermocompression bonding, and therefore the dimensional stability of the wiring board is less likely to be lowered.

  The adhesive sheet is preferably formed mainly of an organic material made of a thermoplastic resin in order to enable thermocompression bonding between the flexible substrate and the capacitor when the wiring substrate is formed. Moreover, it is preferable that an adhesive sheet is flexible like a flexible substrate. If it does in this way, the flexibility of a flexible substrate and an adhesive sheet can be maintained about fields other than the field corresponding to the portion where the capacitor exists. As the thermoplastic resin forming the insulating portion of the adhesive sheet, for example, liquid crystal polymer, thermoplastic polyimide, polyether ether ketone, and the like are suitable. This is because using such a material makes it easy to realize a wiring board having excellent connection reliability at high temperatures. Furthermore, it is preferable that the adhesive sheet also functions as a cover lay for the flexible substrate. Here, the coverlay generally refers to an insulating coating layer (protective film) that covers the surface of the flexible substrate. In this way, it is not necessary to form a protective film for the flexible substrate separately from the adhesive sheet. As a result, the wiring board can be reduced in size in the thickness direction (Z direction). Moreover, the number of parts and man-hours constituting the wiring board are reduced, and it becomes easy to achieve improvement in production efficiency and reduction in manufacturing cost. Furthermore, the structure of the wiring board can be simplified.

  In addition, the surface terminal part of the said flexible substrate and the conductor pillar of the said adhesive sheet are formed, for example with an electroconductive metal. Although it does not specifically limit as said conductive metal, For example, 1 type, or 2 or more types of metals selected from copper, gold | metal | money, silver, platinum, palladium, nickel, tin, lead, titanium, tungsten, molybdenum, tantalum, niobium etc. Can be mentioned. Examples of the conductive metal composed of two or more metals include solder that is an alloy of tin and lead. Lead-free solder (for example, Sn-Ag solder, Sn-Ag-Cu solder, Sn-Ag-Bi solder, Sn-Ag-Bi-Cu solder) as a conductive metal composed of two or more metals Of course, Sn—Zn solder, Sn—Zn—Bi solder, etc.) may be used.

  Further, a module mounting portion is set on the sheet first main surface of the adhesive sheet, a functional module is mounted on the module mounting portion, a surface conductor of the flexible substrate, and a connection terminal of the functional module, It is preferable that they are electrically connected to each other via conductor columns in the adhesive sheet. In this way, multiple functions can be achieved as compared with the case where no functional module is mounted. Therefore, one systemized wiring board with a semiconductor circuit element (so-called system in package: SIP) can be easily realized, and the added value is also increased.

  The functional module may be a module wiring board having a circuit configured to include a plurality of types of electronic components, and may include a functional member such as a MEMS. In this way, compared to a simple substrate having no wiring layer, it is possible to configure a circuit therein and increase the added value. Specific examples of the functional module include an RF module having a wireless communication function, a power supply module having a function of controlling a power supply voltage, and the like. Specific examples of the electronic components constituting the functional module include a chip transistor, a chip diode, a chip resistor, a chip capacitor, a chip coil, and a MEMS element. These electronic components may basically be active components or passive components, and are appropriately selected according to the contents of functions to be realized by the module.

  Further, as another means (means 2) for solving the above-mentioned problem, a flexible substrate having a first substrate main surface and a second substrate main surface, a capacitor main surface, and an array on the capacitor main surface are provided. A plurality of connection terminals arranged in a shape, the capacitor main surface being bonded to the substrate first main surface side, a substantially flat capacitor, and a semiconductor circuit element having a plurality of terminals, the flexible The substrate has an element mounting area in an area corresponding to the portion where the capacitor exists on the second main surface of the substrate, and has a plurality of surface terminal portions in the element mounting area, There is a wiring substrate with a semiconductor circuit element, wherein the plurality of terminals of the mounted semiconductor circuit element are connected to the plurality of surface terminal portions.

  Therefore, according to the wiring board with a semiconductor circuit element of the means 2, the flexible board is reinforced by bonding the substantially flat capacitor. Moreover, the plurality of connection terminals are arranged in an array on the capacitor main surface, that is, evenly distributed on the capacitor main surface, and are reinforced by being connected to the conductor portion of the flexible substrate. As a result, the strength of the flexible substrate becomes uniform in the element mounting region. Therefore, the flexible substrate is deformed and is less likely to cause unevenness, so that the coplanarity in the element mounting region is increased. As a result, connection failure between the terminal of the semiconductor circuit element and the surface terminal portion of the element mounting region is less likely to occur, and high connection reliability can be obtained.

  Further, since the semiconductor circuit element is mounted on the element mounting region set on the second main surface of the substrate, it is exposed to the outside of the wiring substrate. For this reason, the heat generated from the semiconductor circuit element is easily dissipated outside the wiring substrate. Therefore, plastic deformation of the wiring board due to the influence of heat is prevented. Therefore, a wiring board with high dimensional stability can be obtained.

  Note that only one such element mounting region may be set in the region corresponding to the portion where the capacitor exists on the second main surface, or a plurality of such device mounting regions may be set.

  Examples of the semiconductor circuit element mounted on the element mounting region include a semiconductor integrated circuit element, a MEMS (Micro Electro Mechanical Systems) element manufactured by a semiconductor manufacturing process, and the like. Examples of the semiconductor integrated circuit element include a semiconductor integrated circuit chip (IC chip) made of silicon. The MEMS element refers to a fine circuit element manufactured by a micromachining technique based on a semiconductor IC manufacturing process, and is usually composed mainly of silicon. Furthermore, MEMS is a general term for a micro system in which micro-sized sensors, actuators, and control circuits manufactured by a micromachining technology based on an IC manufacturing process are integrated. The size and shape of the element are not particularly limited, but the area of the element mounting region is preferably set smaller than the areas of the capacitor main surface and the capacitor back surface of the capacitor. In this way, the element mounting region of the flexible substrate is reliably reinforced by the capacitor, so that the semiconductor circuit element can be reliably supported.

  As a preferable method (means 3) for producing the wiring board according to means 1 relatively easily and surely, an individual production process for individually producing the capacitor and the flexible board, and the board of the flexible board Bonding the capacitor to the first main surface side, and including a bonding step of electrically connecting the plurality of connection terminals of the capacitor and the plurality of surface terminal portions of the flexible substrate to each other. There is a method of manufacturing a wiring board which is characterized.

  Therefore, according to the means 3, since the capacitor and the flexible substrate are individually manufactured in the individual manufacturing process before the wiring substrate is formed, these electrical inspections can be individually performed. Therefore, since a defective product can be found and removed in advance before bonding, only the capacitor and the flexible substrate that have passed the electrical inspection can be bonded to form the wiring board. Therefore, the probability that the wiring board is defective will be reduced, leading to an improvement in yield.

  Further, the flexible substrate is reinforced by adhering a substantially flat capacitor. In addition, the plurality of connection terminals are arranged in an array, that is, evenly distributed, and are reinforced by being connected to the conductor portion of the flexible substrate. As a result, the strength of the flexible substrate is uniform in a region corresponding to the portion where the capacitor exists. Therefore, the flexible substrate is deformed and is less likely to cause unevenness, so that the coplanarity in the region is increased. As a result, connection failure at the surface terminal portion of the region is less likely to occur, and high connection reliability can be obtained.

  As another preferred method (means 4) for producing the wiring board described in means 1 relatively easily and reliably, in the individual production step, the capacitor and the flexible board are produced individually. In addition, after forming the plurality of via holes penetrating the base material for the adhesive sheet, an adhesive sheet is individually produced by providing a plurality of conductive pillars in the plurality of via holes. The capacitor is bonded onto the first main surface of the substrate via the adhesive sheet, and at that time, the plurality of connection terminals of the capacitor and the plurality of surface terminal portions of the flexible substrate are placed in the adhesive sheet. There is a method for manufacturing a wiring board, wherein the wiring boards are electrically connected to each other through the plurality of conductor pillars.

  Therefore, according to the above means 4, in addition to separately manufacturing the capacitor and the flexible substrate in the individual manufacturing process before forming the wiring board, in order to individually manufacture the adhesive sheet, these electrical inspections are performed. Can be done individually. Therefore, since a defective product can be found and removed in advance before bonding, only the capacitor, the flexible substrate, and the adhesive sheet that have passed the electrical inspection can be bonded to form the wiring substrate. Therefore, the probability that the wiring board is defective will be reduced, leading to an improvement in yield.

  Hereinafter, the manufacturing method of the wiring board described in the means 4 will be described.

  First, an individual production process is performed to individually produce a flexible substrate, a capacitor, and an adhesive sheet.

  Fabrication of the flexible substrate in the individual fabrication process is basically performed according to a conventionally known method. Specifically, for example, a copper-clad laminate having a copper foil on one side or both sides is used as a base material, and via holes penetrating both sides are formed. Furthermore, after a via conductor is formed in each via hole by a method such as filling with a conductive metal paste or copper plating, the copper foil on the surface is etched to pattern the conductor pattern.

  Further, when the capacitor is, for example, a ceramic capacitor having a dielectric layer and an electrode layer, the production of the capacitor in the individual production process is basically performed according to a conventionally known method. For example, a dielectric green sheet is sintered to form a ceramic dielectric layer, and a metal material is deposited on the dielectric layer to form an electrode. In addition, a metal paste is applied to the dielectric green sheet or a metal sheet is laminated and sintered simultaneously.

  The production of the adhesive sheet in the individual production process is performed as follows. For example, a via hole communicating with the adhesive sheet base material is formed at a predetermined position on the adhesive sheet base material to be an adhesive sheet (via hole forming step). Further, a conductor column is formed by filling each via hole with a paste made of a conductive metal (conductor column forming step). And an adhesive sheet is completed by heating a paste, evaporating a solvent etc. and solidifying. Note that, instead of filling the paste made of a conductive metal, the conductor pillars may be formed by plating, for example. In addition, a conductive metal column may be embedded in the via hole.

  Next, a joining process is performed. In the joining step, a flexible substrate, a capacitor, and an adhesive sheet are laminated and a pressing force is applied in the lamination direction while heating, for example, in this state. Specifically, the capacitor is thermocompression-bonded on the first main surface of the flexible substrate mainly composed of non-thermoplastic resin via the adhesive sheet mainly composed of thermoplastic resin. . As a result, the capacitor is bonded onto the flexible substrate via the adhesive sheet, and at that time, the plurality of connection terminals of the capacitor and the plurality of surface terminal portions of the flexible substrate connect the plurality of conductor columns in the adhesive sheet. Are electrically connected to each other. In addition, the heating temperature at this time is suitably set according to the kind of material of the flexible substrate, the kind of the adhesive sheet to be used, the degree of curing of the adhesive sheet, and the like. Further, the heating temperature is preferably set higher than the melting point of the solder used after the joining step. Furthermore, the solder heat resistance of the flexible substrate and the adhesive sheet is preferably set to a temperature higher than the melting point of the solder. If it does in this way, when using solder after a joining process, deformation of a flexible substrate or an adhesive sheet can be prevented.

  As a result, a wiring substrate made of a flexible substrate, a capacitor, and an adhesive sheet is formed. The operation of connecting the plurality of terminals of the semiconductor circuit element to the plurality of surface terminal portions may be performed simultaneously with the bonding process or after the bonding process. It is preferable to carry out simultaneously. In this way, since the number of steps is reduced, the manufacturing cost can be reduced.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment embodying the present invention will be described in detail with reference to FIGS. FIG. 1 is a schematic cross-sectional view showing a wiring board 11 with an IC chip (wiring board with a semiconductor circuit element) of the present embodiment, which includes a wiring board 12 having an IC chip 21 (semiconductor circuit element) and the like. FIG. 2 is an enlarged cross-sectional view of the wiring board 12. 3 and 4 are schematic explanatory diagrams for explaining connections in the inner layer of the ceramic capacitor 131 (capacitor). FIG. 5 is an exploded cross-sectional view illustrating a configuration of a structure including the flexible wiring substrate 51 (flexible substrate), the ceramic capacitor 131, and the adhesive sheet 61. FIG. 6 is an exploded cross-sectional view showing a configuration of a structure including the flexible wiring board 51 and the board main body 95. FIG. 7 is a schematic cross-sectional view showing an adhesive organic material sheet 60 (adhesive sheet substrate). 8 and 9 are schematic cross-sectional views showing a state when the adhesive sheet 61 is produced. FIG. 10 is a schematic cross-sectional view showing a state when the flexible wiring board 51, the ceramic capacitor 131, and the adhesive sheet 61 are joined. FIG. 11 is a schematic cross-sectional view showing a state when the flexible wiring board 51 and the board body 95 are joined to each other.

  The flexible wiring board 51 is mainly formed of an insulating base material made of a heat-resistant non-thermoplastic resin (non-thermoplastic polyimide in this embodiment). Note that the glass transition temperature (Tg) of the flexible wiring board 51 is 270 ° C., which is higher than the heating temperature when the wiring board 12 is formed. The heat resistance (long-term heat resistance) is 300 ° C. for 30 minutes, and the solder heat resistance is 300 ° C. for 180 seconds.

  The flexible wiring board 51 has a substrate upper surface 52 (substrate second main surface) and a substrate lower surface 53 (substrate first main surface). An upper surface side wiring layer 54 (conductor pattern) extending in the substrate plane direction is formed on the substrate upper surface 52, and a lower surface side wiring layer 55 (surface conductor, conductor pattern) also extending in the substrate plane direction is formed on the substrate lower surface 53. Has been. The flexible wiring board 51 is provided with a plurality of via conductors 57 that penetrate the substrate upper surface 52 and the substrate lower surface 53. The upper end surface of each via conductor 57 is electrically connected to the upper surface side wiring layer 54, and the lower end surface of each via conductor 57 is electrically connected to the lower surface side wiring layer 55. Thereby, the upper surface side wiring layer 54 and the lower surface side wiring layer 55 are electrically connected to the via conductor 57.

  As shown in FIGS. 1 and 2, the adhesive sheet 61 covers the substrate lower surface 53 side of the flexible wiring substrate 51. Therefore, the adhesive sheet 61 protects the lower surface side wiring layer 55 from dust and moisture. For this reason, the adhesive sheet 61 also functions as a coverlay for the flexible wiring board 51. The adhesive sheet 61 has a function of bonding the flexible wiring substrate 51 and the ceramic capacitor 131.

  As shown in FIGS. 1 and 2, the adhesive sheet 61 is mainly formed of an insulating base material made of a heat-resistant thermoplastic resin. In this embodiment, the insulating base material is formed of thermoplastic polyimide (AURUM, manufactured by Mitsui Chemicals, Inc.). The adhesive sheet 61 is formed thicker than the upper surface side wiring layer 54 and the lower surface side wiring layer 55, and is set to a thickness of about 10 to 30 μm. The glass transition temperature (Tg) of the adhesive sheet 61 is 250 ° C., which is lower than the glass transition temperature of the flexible wiring board 51. The adhesive sheet main body 63 constituting the adhesive sheet 61 has a sheet upper surface 64 (sheet second main surface) and a sheet lower surface 65 (sheet first main surface). The sheet upper surface 64 is bonded to the substrate lower surface 53 of the flexible wiring substrate 51, and the sheet lower surface 65 is bonded to the capacitor upper surface 23 of the ceramic capacitor 131. Further, the adhesive sheet 61 is formed with a plurality of via holes 66 (see FIG. 7) that conduct through the sheet upper surface 64 and the sheet lower surface 65 in a lattice shape. In the via hole 66, a conductor column 62 formed by filling a conductive paste containing copper powder whose surface is coated with silver is provided. Note that the adhesive sheet 61 of the present embodiment does not have a conductor pattern extending in the sheet plane direction.

  As shown in FIGS. 1 and 2, in the adhesive sheet 61, the upper end surface of each conductor column 62 is electrically connected to the lower surface side wiring layer 55 of the flexible wiring substrate 51. On the other hand, the lower end surface of each conductor column 62 is electrically connected to the external terminal electrode 41 of the ceramic capacitor 131.

  The ceramic capacitor 131 shown in FIGS. 1, 2 and 5 is a so-called via array type multilayer ceramic capacitor having a substantially rectangular flat plate shape of 6.0 mm in length × 6.0 mm in width × 0.5 mm in thickness. The ceramic capacitor 131 is a plate-like object having a capacitor upper surface 23 (capacitor main surface) and a capacitor lower surface 24 (capacitor back surface). The capacitor upper surface 23 is in surface contact with the adhesive sheet 61 and is bonded to the substrate lower surface 53 side through the adhesive sheet 61. That is, the ceramic capacitor 131 is bonded to the flexible wiring board 51 through the adhesive sheet 61. The ceramic capacitor 131 has a structure in which a large number of ceramic dielectric layers 132 and a large number of internal electrode layers 141 and 142 are alternately stacked. The ceramic dielectric layer 132 is made of a sintered body of barium titanate, which is a kind of high dielectric constant ceramic, and functions as a dielectric (insulator) between the internal electrode layers 141 and 142. The thickness of the ceramic dielectric layer 132 is set to about 5 μm. The thermal expansion coefficient in the plane direction of the ceramic dielectric layer 132 is 8.3 to 11.6 ppm / ° C. For example, the thermal expansion coefficient at 30 to 300 ° C. is 10.2 ppm / ° C. The Young's modulus of the ceramic dielectric layer 132 is 107.5 GPa. Therefore, the ceramic capacitor 131 of this embodiment has relatively high rigidity. Each of the internal electrode layers 141 and 142 is a layer formed of nickel as a main component and having a thickness of about 1.5 μm to 1.8 μm, and is disposed every other layer inside the ceramic capacitor 131. In the present embodiment, ceramic capacitors 131 having different dimensions, Young's modulus, and thermal expansion coefficients may be used. For example, the dimensions are 1.0 cm length × 1.0 cm width × 0.5 mm thickness, the thermal expansion coefficient in the plane direction of the ceramic dielectric layer 132 is 9.2 to 11.6 ppm / ° C., and the Young's modulus is 107.0 GPa. A ceramic capacitor 131 may be used.

  As shown in FIGS. 1, 2, and 5, the ceramic capacitor 131 has a large number of via holes 143 having an inner diameter of about 100 μm. In each via hole 143, a plurality of via conductors 134 and 137 penetrating between the capacitor upper surface 23 and the capacitor lower surface 24 are formed using nickel as a main material. The via conductors 134 and 137 are arranged in a lattice shape (array shape) over the entire upper surface 23 and the lower surface 24 of the capacitor. Each via conductor 134 passes through each internal electrode layer 141 and electrically connects them to each other. On the other hand, as shown in FIG. 4 and the like, each via conductor 134 is electrically insulated from each internal electrode layer 142 by passing through a clearance hole 144 provided in each internal electrode layer 142. Each via conductor 137 penetrates each internal electrode layer 142 and electrically connects them to each other. On the other hand, as shown in FIG. 3 and the like, each via conductor 137 is electrically insulated from the internal electrode layer 141 by passing through a clearance hole 145 provided in the internal electrode layer 141.

  A plurality of external terminal electrodes 41 (connection terminals) are provided on the upper end surfaces of the via conductors 134 and 137, respectively. Each external terminal electrode 41 is arranged in an array over the entire upper surface 23 of the capacitor. The number of external terminal electrodes 41 is 196, which is equal to the number of via conductors 134 and 137. The center-to-center distance (pitch) between the adjacent external terminal electrodes 41 is set to about 300 μm, and is equal to the pitch between the adjacent via conductors 134 and 137. In the present embodiment, the pitch between the external terminal electrodes 41 is equal in both the vertical direction (the thickness direction in FIG. 1) and the horizontal direction (the horizontal direction in FIG. 1) of the ceramic capacitor 131. The maximum diameter of the external terminal electrodes 41 is set to be slightly smaller than the pitch between the external terminal electrodes 41, and specifically, is set to about 200 μm. The external terminal electrode 41 is electrically connected to the upper surface side wiring layer 54 of the flexible wiring board 51 through the conductor pillar 62, the lower surface side wiring layer 55, and the via conductor 57.

  On the other hand, a plurality of solder bumps 49 (connection terminals) for electrical connection with the terminals 82 of the mother board 81 are arranged in a lattice pattern on the lower end surfaces of the via conductors 134 and 137. Each solder bump 49 is arranged in an array over the entire lower surface 24 of the capacitor. The number of solder bumps 49 is 64, which is smaller than the number of via conductors 134 and 137 and the number of external terminal electrodes 41. The center-to-center distance (pitch) between adjacent solder bumps 49 is equal to the pitch between adjacent via conductors 134 and 137 and the pitch between adjacent external terminal electrodes 41. The maximum diameter of the solder bumps 49 is set to be smaller than the pitch between the solder bumps 49, and specifically, is set to about 200 μm. Each solder bump 49 is electrically connected to each external terminal electrode 41 through each via conductor 134, 137. The solder bump 49 is made of tin-lead solder having a composition of 90 Pb / 10 Sn.

  Then, the wiring substrate 11 with IC chip shown in FIG. 1 is mounted on the mother board 81 by each solder bump 49. The wiring board 11 with IC chip is a BGA (ball grid array) composed of the wiring board 12 and the module wiring board 91 (functional module). The form of the wiring board 11 with IC chip is not limited to BGA alone, and may be, for example, LGA (land grid array), PGA (pin grid array), or the like.

  When energization is performed through the solder bumps 49 from the mother board 81 side and a voltage is applied between each internal electrode layer 141 and the internal electrode layer 142, for example, positive charges accumulate in the internal electrode layer 141, and the internal electrode layer 142 Negative charge accumulates in As a result, the ceramic capacitor 131 functions as a capacitor. In the present embodiment, the ceramic capacitor 131 has a function of removing noise and stabilizing the power to be supplied to the IC chip 21, and is involved in improving the operability of the IC chip 21.

  As shown in FIGS. 1 and 2, an element mounting region 50 is set in a predetermined region (specifically, a region directly above the ceramic capacitor 131) on the substrate upper surface 52 of the flexible wiring substrate 51. In the element mounting region 50, a plurality of surface terminal portions 56 made of flip chip connection pads are set. Each surface terminal portion 56 constitutes a part of the upper surface side wiring layer 54. Each surface terminal portion 56 is arranged in a region corresponding to a portion where the ceramic capacitor 131 exists on the substrate upper surface 52. A part of each surface terminal portion 56 is electrically connected to the external terminal electrode 41 of the ceramic capacitor 131 through the conductor pillar 62 in the adhesive sheet 61. Each surface terminal portion 56 is electrically connected to a bump-shaped surface connection terminal 22 provided on the IC chip 21 having a function as an MPU. The IC chip 21 of the present embodiment is a rectangular flat plate of 4.0 mm long × 4.0 mm wide × 0.7 mm thick, and is made of silicon. That is, the area of the IC chip 21 (element mounting region 50) is set to a size that is about a quarter of the area of the capacitor upper surface 23 of the ceramic capacitor 131. Circuit elements (not shown) are formed on the lower surface layer of the IC chip 21. In addition, a plurality of surface connection terminals 22 (terminals) are provided in a lattice shape on the lower surface side of the IC chip 21.

  In addition, the flexible wiring board 51 has a portion (a protruding portion 58) that protrudes in the planar direction of the wiring substrate 12. In a region corresponding to the sheet lower surface 65 of the adhesive sheet 61 on the lower surface side of the overhang portion 58, a module mounting portion 90 in which a part of the lower surface side wiring layer 55 is disposed is set. The module wiring board 91 is bonded to such a module mounting portion 90. In the present embodiment, the module wiring board 91 is established as a power supply module having a function of controlling the power supply voltage. This power supply module is composed of a circuit including a plurality of types of electronic components 92. More specifically, the module wiring board 91 has a board body 95 having an upper surface 93 and a lower surface 94. In the present embodiment, the substrate body 95 is a resin substrate made of an epoxy resin. A plurality of via holes (through holes) extending in the thickness direction of the module wiring substrate 91 are formed in the substrate body 95 in a lattice shape, and conductor columns 96 made of copper plating are provided in the via holes. . A lower surface side pad 99 is disposed on the lower surface 94 at a position where the lower end surface of each conductor pillar 96 is present. Each lower surface side pad 99 is connected to a bump-shaped surface connection terminal 98 provided on the electronic component 92 side. The electronic component 92 is a component such as a chip transistor or a chip resistor. On the other hand, an upper surface side pad 97 (connecting terminal) is disposed at a position on the upper surface 93 where there is an upper end surface of each conductor pillar 96.

  The module wiring board 91 is bonded to the substrate lower surface 53 side of the flexible wiring board 51 through the adhesive sheet 61. The module wiring board 91 may be bonded to the substrate upper surface 52 side of the flexible wiring board 51 via the adhesive sheet 61. As shown in FIG. 1, the upper surface side pad 97 of the substrate body 95 is electrically connected to the lower surface side wiring layer 55 of the flexible wiring substrate 51 via the conductor pillars 62 in the adhesive sheet 61.

  As a result, a current flows through a path (or a path opposite to this) of the lower surface side pad 99 to the conductor column 96 to the upper surface side pad 97 to the conductor column 62. Therefore, in the wiring board 11 with an IC chip having such a structure, the flexible wiring board 51 side and the electronic component 92 side are electrically connected via the conductor pillar 96 of the board body 95. Therefore, signal input / output is performed between the flexible wiring board 51 and the electronic component 92 via the module wiring board 91.

  Therefore, in the wiring substrate 11 with an IC chip having such a structure, when the IC chip 21 is mounted in the element mounting region 50, the surface connection terminal 22 of the IC chip 21 is connected to the upper surface side wiring layer 54 (flip chip connection pad). Is electrically connected to the via conductor 57 of the flexible wiring board 51. Therefore, signal input / output is performed between the wiring board 12 and the IC chip 21 and power for operating the IC chip 21 as an MPU is supplied.

  Next, a procedure for manufacturing the wiring substrate 11 with the IC chip will be described.

First, an individual manufacturing process is performed, and the ceramic capacitor 131, the flexible wiring board 51, and the adhesive sheet 61 are individually manufactured. The production of the ceramic capacitor 131 in the individual production process is basically performed by a conventionally known method. Specifically, a multilayer body forming step is performed to stack a plurality of dielectric green sheets on which internal electrodes are printed. Then, using a conventionally known laminating apparatus, a pressing force is applied in the sheet stacking direction under a predetermined temperature condition, whereby the respective dielectric green sheets are pressed and integrated. As a result, a green sheet laminate having a thickness of about 1 mm is obtained. In the present embodiment, to set the temperature at the time of stacking crimped 60 ° C. to 80 ° C., it has decided to set the pressing force to ^{300kg / cm 2 ~1000kg / cm 2} . Further, the number of stacked layers is set to about 100 to 120 layers. About the number of lamination | stacking, it can change arbitrarily according to the specification etc. which are requested | required.

  Next, by irradiating a laser beam using a laser processing machine, a large number of via holes 143 having a diameter of about 120 μm are formed through the green sheet laminate. Further, using a paste press-fitting and filling device, the via holes 143 are filled with nickel paste for via conductors to form via conductors 134 and 137.

  Then, the green sheet laminate is degreased and further fired at a predetermined temperature for a predetermined time. As a result, barium titanate and nickel in the paste are simultaneously sintered to form a ceramic sintered body. If the ceramic sintered body is broken, the ceramic capacitor 131 can be obtained.

  In addition, the flexible wiring board 51 in the individual manufacturing process is basically manufactured by a conventionally known method. That is, a drilling process is performed on the copper-clad laminate using a mechanical drill, a YAG laser, or a carbon dioxide gas laser, and via holes (not shown) penetrating the copper-clad laminate are formed in advance at predetermined positions. And the via conductor 57 is formed in a via hole by performing electroless copper plating and electrolytic copper plating according to a conventionally known method. Further, the upper surface side wiring layer 54 and the lower surface side wiring layer 55 are formed by etching both surfaces of the copper clad laminate. As a result, the flexible wiring board 51 is obtained.

Furthermore, the adhesive sheet 61 is produced in an individual production process. Specifically, the adhesive organic material sheet 60 (see FIG. 7) to be the adhesive sheet 61 is punched using a mechanical drill, YAG laser, CO ₂ laser, punching device, etc. A via hole 66 (see FIG. 8) penetrating the sheet 60 is formed in advance at a predetermined position (via hole forming step). The via hole 66 has an upper opening having a diameter of approximately 117 μm and a lower opening having a diameter of approximately 113 μm.

Next, the conductive pillar 62 is formed by filling the via hole 66 with a conductive paste by a conventionally known printing method. Specifically, the adhesive organic material sheet 60 is placed on a support base (not shown). Next, using a printing mask having an opening at a position corresponding to the via hole 66, the printing pressure is set to 2 kgf / cm ² , the printing speed is set to 50 mm / sec, and the surface contains copper powder coated with silver on the surface. The paste is printed to form a paste filling layer. And after removing from a printing apparatus, a conductive paste is heated and a solvent etc. are evaporated and it solidifies. Next, temporary curing is performed by heating at a temperature of about 100 ° C. for about 30 minutes. Thereby, the conductive pillar 62 made of the conductive paste is slightly cured, and the adhesive sheet 61 is completed. As a result, the conductor pillar 62 is formed in the via hole 66 (conductor pillar forming step). At this time, the tip end portion of the conductor column 62 protrudes from the upper surface of the adhesive organic material sheet 60 (see FIG. 9). With such a structure, when the adhesive sheet 61 and the flexible wiring board 51 are joined, the upper end portion of the conductor column 62 and the lower surface side wiring layer 55 of the flexible wiring board 51 are pressed against each other. Therefore, for example, compared with the case where the tip portion is flat, the bonding strength with the conductor portion of the other substrate is increased, and the connection reliability is easily improved.

  The module wiring board 91 (board body 95) is basically manufactured by a conventionally known method. That is, drilling is performed on the copper clad laminate using a mechanical drill, and via holes (not shown) penetrating the copper clad laminate are formed in advance at predetermined positions. In addition, you may form a via hole by performing a laser drilling process with respect to a copper clad laminated board using a YAG laser or a carbon dioxide gas laser. Then, electroless copper plating and electrolytic copper plating are performed according to a conventionally known method to form the conductive pillar 96 in the via hole. Further, the copper foil on both sides of the copper clad laminate is etched to form the upper surface side pad 97 and the lower surface side pad 99 by, for example, a subtractive method. Specifically, after the electroless copper plating, electrolytic copper plating is performed using the electroless copper plating layer as a common electrode. Further, the dry film is laminated, and the dry film is exposed and developed to form a dry film in a predetermined pattern. In this state, unnecessary electrolytic copper plating layer, electroless copper plating layer and copper foil are removed by etching. Thereafter, the substrate main body 95 is obtained by peeling the dry film. The upper surface side pad 97 and the lower surface side pad 99 may be formed by a semi-additive method. Specifically, after electroless copper plating, exposure and development are performed to form a predetermined pattern of plating resist. In this state, after electrolytic copper plating is performed using the electroless copper plating layer as a common electrode, the resist is first dissolved and removed, and unnecessary electroless copper plating layer and copper foil are removed by etching. As a result, a substrate body 95 is obtained.

  Next, an electrical inspection process (individual inspection process) is performed, and an electrical inspection is individually performed on the completed ceramic capacitor 131, flexible wiring board 51, and adhesive sheet 61. At the same time, an electrical inspection is performed on the completed module wiring board 91. The electrical inspection in the present embodiment refers to a general in-circuit test performed using an in-circuit tester, for example. Further, the appearance inspection may be individually performed on the completed ceramic capacitor 131, the flexible wiring board 51, the adhesive sheet 61, and the module wiring board 91 at this time. At this time, if a defective product is found, the defective product is removed in advance. And the process after a positioning process (a 1st positioning process, a 2nd positioning process) is performed only using the ceramic capacitor 131, the flexible wiring board 51, the adhesive sheet 61, and the module wiring board 91 which passed the electrical inspection and the external appearance inspection. Therefore, the probability that the wiring substrate 11 with the IC chip becomes a defective product is reduced, leading to an improvement in yield.

  In the first positioning step, first, the flexible wiring substrate 51, the adhesive sheet 61, and the ceramic capacitor 131 are sequentially stacked on the flat lower jig 101. Then, the spacer 102 is placed on the lower jig 101. Note that the maximum value of the thickness of the spacer 102 is substantially equal to the height of the laminate composed of the flexible wiring substrate 51, the ceramic capacitor 131, and the adhesive sheet 61. A plurality of positioning pins 105 protruding from the lower jig 101 are inserted into the spacer 102. For this reason, the position shift to the plane direction of the spacer 102 and a laminated body is prevented. Thereafter, the flat upper jig 104 is placed on the adhesive sheet 61 and the spacer 102 (see FIG. 10). The lower jig 101 has a structure in which a cushion material 103 is attached to the lower surface side of the lower jig 101. Therefore, the upper surface side wiring layer 54 protruding from the flexible wiring board 51 comes into contact with the cushion material 103 which is an elastic body. At this time, the cushion material 103 is elastically deformed and follows the uneven shape on the flexible wiring board 51 side. Thereby, it is possible to apply a pressing force evenly to the adhesive sheet 61. In addition, it is also possible to perform positioning using what is called a die mounter apparatus which has an image recognition apparatus which detects the position of a board | substrate etc. instead of performing positioning using the above jig | tools.

  Next, the first joining step (joining step) is performed in the following manner. Specifically, in this embodiment, a pressing force (4 MPa) is applied in the laminating direction (joining direction) while heating to a temperature of 260 ° C. or higher under a vacuum of 20 Torr (≈2666 Pa) or less (vacuum hot press ). Accordingly, the flexible wiring substrate 51, the ceramic capacitor 131, and the adhesive sheet 61 are pressed along the stacking direction, and the plasticity of the adhesive sheet 61 is increased by heat. Then, the ceramic capacitor 131 is bonded (thermocompression bonding) to the lower surface 53 of the flexible wiring substrate 51 through the adhesive sheet 61. At this time, the lower surface side wiring layer 55 of the flexible wiring substrate 51 is in pressure contact with the conductor column 62 of the adhesive sheet 61, and the external terminal electrode 41 of the ceramic capacitor 131 is in pressure contact with the conductor column 62. Therefore, the external terminal electrode 41 of the ceramic capacitor 131 and the surface terminal portion 56 of the flexible wiring board 51 are electrically connected to each other via the conductor pillar 62 in the adhesive sheet 61, thereby forming the wiring board 12. That is, since the flexible wiring board 51, the ceramic capacitor 131, and the adhesive sheet 61 are joined in a vacuum atmosphere, generation of voids due to air entrainment can be effectively suppressed.

  Next, a 2nd positioning process and a 2nd joining process are implemented in the following way. In addition, you may perform a 2nd positioning process and a 2nd joining process before a 1st positioning process and a 1st joining process. Moreover, if it is performed simultaneously with the first positioning step and the first joining step, the number of steps can be reduced and the cost can be reliably reduced.

  In the second positioning step, first, the flexible wiring board 51 and the adhesive sheet 61 are placed on the flat lower jig 151. At this time, the adhesive sheet 61 is placed on the upper side. In this case, a plurality of positioning pins 155 protruding from the lower jig 151 are inserted into the outer peripheral portion of the flexible wiring board 51. Thereby, the position shift to the plane direction of the flexible wiring board 51 is prevented. Next, the substrate body 95 is placed on the flexible wiring substrate 51. At this time, the adhesive sheet 61 is positioned between the upper surface side wiring layer 54 of the flexible wiring substrate 51 and the lower surface side pad 99 of the substrate body 95 facing each other. Then, the spacer 152 is placed on the lower jig 151. Note that the thickness of the spacer 152 is substantially equal to the height of the substrate body 95. A plurality of positioning pins 155 are inserted through the spacer 152. For this reason, displacement of the substrate body 95 in the planar direction is prevented. Thereafter, a flat upper jig 154 is placed on the substrate body 95 and the spacer 152 (see FIG. 11).

  Next, a second joining step is performed. Specifically, in this embodiment, a pressing force (4 MPa) is applied in the laminating direction while heating to a temperature of 260 ° C. or higher under a vacuum of 20 Torr (≈2666 Pa) or less (vacuum hot press). As a result, the substrate body 95 is pressed toward the flexible wiring substrate 51, and the plasticity of the adhesive sheet 61 increases due to heat. Then, the substrate body 95 is bonded (thermocompression bonding) to the substrate lower surface 53 side of the flexible wiring substrate 51 through the adhesive sheet 61 in such a state. At this time, the conductor column 62 of the adhesive sheet 61 and the upper surface side pad 97 of the substrate body 95 are pressed against each other. Therefore, the conductor column 96 of the substrate body 95 and the lower surface side wiring layer 55 of the flexible wiring substrate 51 are electrically connected to each other via the conductor column 62 in the adhesive sheet 61. That is, since the bonding of the substrate body 95 to the flexible wiring substrate 51 is performed in a vacuum atmosphere, generation of voids due to air entrainment can be effectively suppressed.

  The upper jig 154 has a structure in which a cushion material 153 is attached to the lower surface side of the same jig 154. Therefore, the lower surface side pad 99 protruding from the lower surface 94 of the substrate body 95 comes into contact with the cushion material 153 which is an elastic body. At this time, the cushion material 153 is elastically deformed to follow the uneven shape on the substrate body 95 side. Thereby, a pressing force can be applied evenly to the substrate body 95.

  Next, solder paste printing is performed on the capacitor lower surface 24 of the ceramic capacitor 131 to form solder bumps 49. In this way, the solder bumps 49 do not need to get in the way when the first joining step is performed. In addition, when solder bump formation is performed after the first bonding step, the solder bump 49 is unlikely to encounter a high temperature of 260 ° C. or higher, unlike when solder bump formation is performed before the first bonding step. Therefore, it is not always necessary to select a high melting point solder, and the degree of freedom in selecting a solder material is increased.

  However, the solder bump 49 may be formed at the same time when the adhesive sheet 61 is produced, and then the first joining step may be performed. In this way, when the adhesive sheet 61 is inspected in the electrical inspection step, the inspection including the solder bumps 49 can be performed, so that the wiring board 11 with an IC chip is manufactured in a state where the solder bumps 49 are defective. Can be prevented.

  In addition, a plurality of electronic components 92 are placed on the lower surface 94 side of the substrate body 95. At this time, the surface connection terminal 98 on the electronic component 92 side and the lower surface side pad 99 on the board body 95 side are aligned. And by heating and reflowing each surface connection terminal 98, the surface connection terminal 98 and the lower surface side pad 99 are joined.

  Thereafter, the IC chip 21 is placed on the surface terminal portion 56 of the flexible wiring board 51. At this time, the surface connection terminals 22 on the IC chip 21 side and the upper surface side wiring layer 54 on the flexible wiring board 51 side are aligned. And by heating and reflowing each surface connection terminal 22, the surface connection terminal 22 and the upper surface side wiring layer 54 are joined. At this stage, a wiring board 11 with an IC chip (so-called system-in-package: SIP) in which a plurality of functions are integrated and systematized is completed.

  Further, the solder bumps 49 of the ceramic capacitor 131 and the terminals 82 on the mother board 81 side are aligned, and the wiring board 11 with IC chip is placed on the mother board 81. Then, the solder bumps 49 and the terminals 82 are joined by heating and reflowing the solder bumps 49. Thereby, the wiring substrate 11 with IC chip is mounted on the mother board 81.

  Therefore, according to the present embodiment, the following effects can be obtained.

  (1) In the wiring substrate 11 with IC chip of the present embodiment, the flexible wiring substrate 51 is reinforced by bonding a ceramic capacitor 131 having a substantially rectangular flat plate shape. In addition, the plurality of external terminal electrodes 41 are arranged in an array on the capacitor upper surface 23, that is, evenly arranged on the capacitor upper surface 23, and they are reinforced by being connected to the lower surface side wiring layer 55 of the flexible wiring substrate 51. Is done. As a result, the strength of the flexible wiring board 51 is uniform in the element mounting region 50. Therefore, since the flexible wiring board 51 is not easily deformed to cause unevenness, the coplanarity in the element mounting region 50 is increased. As a result, connection failure between the surface connection terminal 22 of the IC chip 21 and the surface terminal portion 56 of the element mounting region 50 is less likely to occur, and high connection reliability can be obtained.

  Further, since the IC chip 21 is mounted on the element mounting region 50 set on the upper surface 52 of the substrate, it is exposed to the outside of the wiring substrate 12. For this reason, the heat generated from the IC chip 21 is easily dissipated to the outside of the wiring board 12. Therefore, plastic deformation of the wiring board 12 due to the influence of heat is prevented. Therefore, the wiring board 12 with high dimensional stability can be obtained.

  (2) The ceramic capacitor 131 of this embodiment is bonded to the flexible wiring board 51 via the adhesive sheet 61 and exposed to the outside. Therefore, for example, compared to a case where the ceramic capacitor 131 is embedded in a laminate including the flexible wiring board 51 and the adhesive sheet 61, the ceramic capacitor 131 can be easily functioned as a heat sink. Therefore, plastic deformation of the flexible wiring board 51 and the adhesive sheet 61 due to the influence of heat from the ceramic capacitor 131 is prevented. For this reason, the wiring board 12 with high dimensional stability can be obtained. Further, since the ceramic capacitor 131 is exposed to the outside, it is easy to increase the size and functionality of the ceramic capacitor 131.

  (3) The flexible wiring board 51 and the ceramic capacitor 131 of this embodiment are bonded via an adhesive sheet 61. Therefore, when the external terminal electrode 41 of the capacitor upper surface 23 contacts the sheet lower surface 65, the sheet lower surface 65 can follow the uneven shape on the capacitor upper surface 23 side. Is less likely to occur. Therefore, the adhesion is increased and the coplanarity of the sheet upper surface 64 is increased. Therefore, the coplanarity of the element mounting area 50 of the flexible wiring board 51 becomes higher.

  (4) Since the wiring board 11 with IC chip of the present embodiment includes the module wiring board 91 in addition to the wiring board 12, the number of functions can be increased as compared with the case where the module wiring board 91 is not provided. Therefore, it becomes easy to realize one systemized wiring board 11 with an IC chip (so-called system-in-package: SIP), and the added value is also increased.

  (5) In the flexible wiring board 51 of this embodiment, conductor patterns (upper surface side wiring layer 54 and lower surface side wiring layer 55) are formed on both the upper surface 52 and the lower surface 53 of the substrate. For this reason, even if the adhesive sheet 61 on which no conductor pattern is formed is used, it is possible to configure a large number of circuits inside, and the added value can be increased.

  (6) The adhesive sheet 61 of this embodiment is formed mainly of an insulating substrate made of a thermoplastic resin (thermoplastic polyimide). Therefore, for example, even if the flexible wiring board 51 and the adhesive sheet 61 are joined in a state of being displaced from each other, the adhesive sheet 61 can be peeled from the flexible wiring board 51 by heating the adhesive sheet 61 again. For this reason, it becomes possible to rejoin the flexible wiring board 51 and the adhesive sheet 61 easily. Similarly, even if the ceramic capacitor 131 and the adhesive sheet 61 are joined with their positions being shifted from each other, the adhesive sheet 61 can be peeled from the flexible wiring board 51 by heating the adhesive sheet 61 again. For this reason, the ceramic capacitor 131 and the adhesive sheet 61 can be easily joined again. Further, even if the substrate main body 95 is bonded to the flexible wiring substrate 51 in a state of being displaced, the substrate main body 95 can be peeled from the adhesive sheet 61 by heating the adhesive sheet 61 again. For this reason, it is possible to easily rejoin the substrate body 95 to the flexible wiring substrate 51.

  (7) In the manufacturing method of this embodiment, before the wiring substrate 12 is formed, the ceramic capacitor 131, the flexible wiring substrate 51, and the adhesive sheet 61 are individually manufactured in an individual manufacturing process. Can be done. Therefore, since a defective product can be found and removed in advance before joining, only the ceramic capacitor 131, the flexible wiring board 51, and the adhesive sheet 61 that have passed the electrical inspection can be joined to form the wiring board 12. . Therefore, the probability that the wiring board 12 becomes a defective product is reduced, leading to an improvement in yield.

  (8) In the manufacturing method of the present embodiment, since the first bonding process is performed before the IC chip 21 is mounted on the element mounting region 50 of the flexible wiring board 51, the load of the upper jig 104 is IC It does not join the chip 21. Therefore, the occurrence of cracks in the IC chip 21 can be reliably prevented. In the present embodiment, since the second bonding step is performed before the electronic component 92 is mounted on the upper surface side pad 97 of the substrate body 95, the load of the upper jig 154 is applied to the electronic component 92. There is no. Therefore, the occurrence of cracks in the electronic component 92 can be reliably prevented.

  In addition, you may change embodiment of this invention as follows.

  In the above embodiment, the ceramic capacitor 131 is electrically connected to the IC chip 21 via one flexible wiring board 51 and one adhesive sheet 61. However, the ceramic capacitor 131 may be electrically connected to the IC chip 21 via the plurality of flexible wiring boards 51 and the plurality of adhesive sheets 61. For example, as shown in FIG. 12, the ceramic capacitor 131 may be connected to the IC chip 21 through two flexible wiring boards 51 and two adhesive sheets 61. In this way, compared to the case where the flexible wiring board 51 has only one layer, it becomes possible to configure more circuits inside, and the added value can be increased.

  Moreover, the flexible wiring board 51 and the adhesive sheet 61 of FIG. 12 may be extended, and the extended portion may be folded downward, for example. Then, the extended portion may be bonded to the capacitor lower surface 24 side of the ceramic capacitor 131. In this way, the ceramic capacitor 131 is embedded in the laminated portion including the two flexible wiring boards 51 and the two adhesive sheets 61.

  In the above embodiment, the external terminal electrode 41 is a connection terminal on the capacitor upper surface 23, and the solder bump 49 is a connection terminal on the capacitor lower surface 24. However, for example, as shown in FIG. 12, the upper and lower end portions of the via conductors 134 and 137 may be connection terminals on the capacitor upper surface 23 and the capacitor lower surface 24.

  Next, the technical ideas grasped by the embodiment described above are listed below.

  (1) A flexible substrate having a first substrate main surface and a second substrate main surface, a capacitor main surface, a plurality of connection terminals arranged in an array on the capacitor main surface, and the capacitor main surface A substantially flat capacitor having a surface bonded to the substrate first main surface side, and the flexible substrate is set in a region corresponding to the portion where the capacitor exists on the second substrate main surface, and a semiconductor circuit element And a plurality of surface terminal portions formed in the element mounting region to which a plurality of terminals of the semiconductor circuit element can be connected.

  (2) A flexible substrate having a first substrate main surface and a second substrate main surface; a capacitor main surface; a plurality of connection terminals arranged in an array on the capacitor main surface; A substantially flat plate-like capacitor whose surface is bonded to the substrate first main surface side, and the flexible substrate has a plurality of surface terminal portions in a region corresponding to the capacitor existing portion on the substrate second main surface. And the plurality of surface terminal portions constitute a part of a conductor pattern extending in the substrate plane direction.

(3) a plurality of flexible substrates having a substrate first main surface and a substrate second main surface; a capacitor main surface; and a plurality of connection terminals arranged in an array on the capacitor main surface, A substantially flat capacitor having a capacitor main surface bonded to the substrate first main surface side, a sheet first main surface, a sheet second main surface, and between the sheet first main surface and the sheet second main surface. A plurality of adhesive sheets having a plurality of conductive pillars, and the capacitor is embedded in a laminated portion composed of the plurality of flexible substrates and the plurality of adhesive sheets, and the uppermost flexible substrate includes: A wiring board having a plurality of surface terminal portions in a region corresponding to a portion where the capacitor exists on the second main surface of the substrate.

  (4) A flexible substrate having a first substrate main surface and a second substrate main surface, a capacitor main surface, and a plurality of connection terminals arranged in an array on the capacitor main surface, wherein the capacitor main surface A substantially flat capacitor having a surface bonded to the substrate first main surface side, and a semiconductor circuit element having a plurality of terminals, wherein the flexible substrate is formed on the second main surface of the substrate at the portion where the capacitor exists. The corresponding area has an element mounting area, the element mounting area has a plurality of surface terminal portions, and the semiconductor circuit elements mounted on the element mounting area have the plurality of terminals A wiring substrate with a semiconductor circuit element, wherein the wiring board is connected to a plurality of surface terminal portions, and the area of the capacitor main surface is set to be 1 to 5 times the area of the element mounting region.

In this embodiment, the schematic sectional drawing which shows the wiring board with an IC chip which consists of a wiring board. The expanded sectional view which shows a wiring board. Schematic explanatory drawing for demonstrating the connection in the inner layer of a ceramic capacitor. Schematic explanatory drawing for demonstrating the connection in the inner layer of a ceramic capacitor. The exploded sectional view showing composition of a structure which consists of a flexible wiring board, a ceramic capacitor, and an adhesive sheet. The exploded sectional view showing composition of a structure which consists of a flexible wiring board, an adhesive sheet, and a substrate body. The schematic sectional drawing which shows an adhesive organic material sheet in the preparation process of an adhesive sheet. The schematic sectional drawing which shows the process of forming a via hole in an adhesive organic material sheet in the preparation process of an adhesive sheet. The schematic sectional drawing which shows the process of forming a conductor pillar in a via hole in the preparation process of an adhesive sheet. The schematic sectional drawing which shows a mode when a flexible wiring board, a ceramic capacitor, and an adhesive sheet are joined in the manufacture process of a wiring board with an IC chip. The schematic sectional drawing which shows a mode when a flexible wiring board and a board | substrate main body are mutually joined in the manufacture process of a wiring board with an IC chip. The schematic sectional drawing which shows the wiring board with an IC chip in other embodiment. The schematic sectional drawing which shows the wiring board in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Wiring board with IC chip as wiring board with semiconductor circuit element 12 ... Wiring board 21 ... IC chip 22 as semiconductor circuit element ... Surface connection terminal 23 as terminal of semiconductor circuit element ... Capacitor upper surface as capacitor main surface 24 ... Capacitor lower surface 41 as capacitor back surface ... External terminal electrode 49 as connection terminal on capacitor main surface ... Solder bump 50 as connection terminal on capacitor back surface ... Element mounting region 51 ... Flexible wiring substrate as flexible substrate 52 ... Substrate upper surface 53 as substrate second main surface ... Substrate lower surface 55 as substrate first main surface ... Lower surface side wiring layer 56 as surface conductor of flexible substrate ... Surface terminal portion 60 ... Adhesion as base material for adhesive sheet Organic material sheet 61 ... adhesive sheet 62 ... conductor column 64 ... second sheet main surface Sheet upper surface 65 ... sheet lower surface 66 as sheet first main surface ... via hole 90 ... module mounting portion 91 ... module wiring board 97 as a functional module ... upper surface side pad 131 as a functional module connection terminal ... as a capacitor Ceramic capacitors 134, 137 ... via conductors

Claims (9)

A flexible substrate having a first substrate main surface and a second substrate main surface;
A substantially flat capacitor having a capacitor main surface, having a plurality of connection terminals arranged in an array on the capacitor main surface, wherein the capacitor main surface is bonded to the substrate first main surface side; Prepared,
The flexible substrate has a plurality of surface terminal portions in a region corresponding to a portion where the capacitor exists on the second main surface of the substrate. A first sheet main surface bonded on the capacitor main surface, a second sheet main surface bonded on the first substrate main surface of the flexible substrate, and between the first sheet main surface and the second sheet main surface. An adhesive sheet having a plurality of conductive pillars that conduct through,
The capacitor and the flexible substrate are bonded via the adhesive sheet, and at least a part of the plurality of connection terminals and the plurality of surface terminal portions are mutually connected via a plurality of conductor columns in the adhesive sheet. The wiring board according to claim 1, wherein the wiring board is electrically connected.   A module mounting portion is set on the first main surface of the adhesive sheet, a functional module is mounted on the module mounting portion, and a surface conductor of the flexible substrate and a connection terminal of the functional module are bonded to each other. The wiring board according to claim 2, wherein the wiring boards are electrically connected to each other via conductor columns in the sheet.   The capacitor electrically connects a capacitor back surface, a plurality of connection terminals arranged in an array on the capacitor back surface, a plurality of connection terminals on the capacitor main surface, and a plurality of connection terminals on the capacitor back surface. 4. The wiring board according to claim 1, wherein the wiring board is a via array type capacitor having a plurality of via conductors.   The wiring board according to claim 1, wherein the capacitor is a ceramic capacitor. A flexible substrate having a first substrate main surface and a second substrate main surface;
A substantially flat capacitor having a capacitor main surface, having a plurality of connection terminals arranged in an array on the capacitor main surface, the capacitor main surface being bonded to the substrate first main surface side;
A semiconductor circuit element having a plurality of terminals,
The flexible substrate has an element mounting region in a region corresponding to the capacitor existing portion on the substrate second main surface, and has a plurality of surface terminal portions in the element mounting region.
The wiring board with a semiconductor circuit element, wherein the plurality of terminals of the semiconductor circuit element mounted on the element mounting region are connected to the plurality of surface terminal portions. A method for manufacturing a wiring board according to any one of claims 1 to 5,
An individual manufacturing step of individually manufacturing the capacitor and the flexible substrate;
Bonding the capacitor to the substrate first main surface side of the flexible substrate, and electrically connecting the plurality of connection terminals of the capacitor and the plurality of surface terminal portions of the flexible substrate at that time A method for manufacturing a wiring board comprising the steps of: In the individual manufacturing step, in addition to individually manufacturing the capacitor and the flexible substrate, a plurality of conductive pillars are provided in the plurality of via holes after the formation of the plurality of via holes penetrating the adhesive sheet base material. To make individual adhesive sheets,
In the bonding step, the capacitor is bonded to the first main surface of the flexible substrate via the adhesive sheet, and at that time, the plurality of connection terminals of the capacitor and the plurality of surfaces of the flexible substrate The method of manufacturing a wiring board according to claim 7, wherein the terminal portion is electrically connected to each other through the plurality of conductor pillars in the adhesive sheet.   In the joining step, the capacitor is thermocompression-bonded on the first main surface of the flexible substrate mainly composed of a non-thermoplastic resin through the adhesive sheet mainly composed of a thermoplastic resin. The method for manufacturing a wiring board according to claim 8.

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