JP5808047B2 - Wiring board and mounting structure thereof - Google Patents

Description

  The present invention relates to a wiring board used for electronic devices (for example, various audiovisual devices, home appliances, communication devices, computer devices and peripheral devices thereof), and a mounting structure thereof.

  2. Description of the Related Art Conventionally, as a mounting structure in an electronic device, an electronic component mounted on a wiring board is used.

  With respect to the wiring substrate, Patent Document 1 discloses that a through hole is formed in a core substrate obtained by impregnating a glass cloth with an insulating resin by a drill, and a through hole via made of Cu or the like is formed on a side wall of the through hole by a plating method or the like ( A configuration in which a through-hole conductor) is formed is disclosed.

  By the way, when heat generated during mounting or operation of electronic components is applied to the wiring board, the glass cloth and the through-hole conductor exposed on the side wall of the through-hole are caused by the difference in thermal expansion coefficient between the glass cloth and the through-hole conductor. Thermal stress is likely to occur between In particular, when the through hole is formed by a drill, the surface of the glass cloth exposed on the side wall of the through hole is likely to be smooth, so that the through hole conductor is easily peeled off due to the thermal stress described above.

  As a result, if the side wall of the through hole and the through hole conductor are peeled off, the through hole conductor is disconnected, and the electrical reliability of the wiring board is likely to be lowered.

JP 2006-324642 A

  The present invention provides a wiring board that meets the demand for improving electrical reliability and a mounting structure thereof.

A wiring board according to an embodiment of the present invention includes a base, a through hole that penetrates the base in the thickness direction, and a through-hole conductor that covers an inner wall of the through hole, and the base includes a plurality of glass fibers, A resin disposed between the plurality of glass fibers, and the inner wall of the through hole is formed by a cutting surface in which the glass fiber and the resin are cut by blasting,
The glass fiber has a groove-shaped recess on the cutting surface, and the recess is filled with a part of the through-hole conductor.

  A mounting structure according to an aspect of the present invention includes the above wiring board and an electronic component that is mounted on the wiring board and electrically connected to the through-hole conductor.

According to the wiring board according to one aspect of the present invention, the base body includes a plurality of glass fibers and a resin disposed between the plurality of glass fibers, and the inner wall of the through hole is formed by blasting the glass fibers and the resin. It is formed with the cut surface as it is cut. For this reason, a through-hole conductor can be formed by depositing a conductive material without lowering the adhesion between the fiber exposed to the inner wall of the through-hole and the resin, and the adhesion between the inner wall of the through-hole and the through-hole conductor can be formed. Strength can be increased.
Further, since the glass fiber has a groove-like recess on the cutting surface and the recess is filled with a part of the through-hole conductor, peeling between the glass fiber and the through-hole conductor can be reduced. . Therefore, disconnection of the through-hole conductor can be reduced, and as a result, a wiring board having excellent electrical reliability can be obtained.

FIG. 1A is a cross-sectional view along the thickness direction of a mounting structure according to an embodiment of the present invention, and FIG. 1B is a through hole of the mounting structure according to an embodiment of the present invention. It is an enlarged view of the surface of the inner wall. 2A to 2D are cross-sectional views cut in the thickness direction for explaining the manufacturing process of the mounting structure shown in FIG.

  Hereinafter, a mounting structure including a wiring board according to an embodiment of the present invention will be described in detail based on the drawings.

  The mounting structure 1 shown in FIG. 1A is used for electronic devices such as various audiovisual devices, home appliances, communication devices, computer devices, and peripheral devices thereof. The mounting structure 1 includes an electronic component 2 and a flat wiring board 4 on which the electronic component 2 is flip-chip mounted via bumps 3.

  The electronic component 2 is a semiconductor element such as an IC or LSI, for example, and a base material is formed of a semiconductor material such as silicon, germanium, gallium arsenide, gallium arsenide phosphorus, gallium nitride, or silicon carbide. The electronic component 2 is set to have a thickness of 0.1 mm to 1 mm, for example.

  The bump 3 is made of a conductive material such as solder including lead, tin, silver, gold, copper, zinc, bismuth, indium, aluminum, or the like.

  The wiring substrate 4 includes a flat core substrate 5 and a pair of wiring layers 6 formed on both sides of the core substrate 5. The wiring board 4 is set to have a thickness of, for example, 0.2 mm or more and 1.2 mm. In addition, the wiring board 4 is set to have a coefficient of thermal expansion larger than that of the electronic component 2 in the planar direction, for example.

  The core substrate 5 is intended to increase the strength of the wiring substrate 4 while achieving electrical connection between the pair of wiring layers 6. The core substrate 5 includes a flat substrate 7 having a plurality of through-holes T penetrating in the thickness direction and a plurality of through-holes. A cylindrical through-hole conductor 8 covering the inner wall of the hole T and a columnar insulator 9 formed in a region surrounded by the through-hole conductor 8 are included.

  The base 7 increases the rigidity of the core substrate 5, and as shown in FIGS. 1A and 1B, the resin 10, the inorganic insulating particles 11 coated with the resin, and the resin are coated. And a flat substrate 13 made of a plurality of glass fibers 12.

  In this substrate 7, a layer made of the resin 10 disposed between the substrate 13 and the glass fibers 12 of the substrate 13 is referred to as a fiber layer 14. In addition, a layer that is disposed between the fiber layers 14 and does not include glass fibers and includes the resin 10 and the inorganic insulating particles 11 is referred to as a resin layer 15. The boundary between the fiber layer 14 and the resin layer 15 is constituted by an interface between the glass fiber 12 of the fiber layer 14 and the resin 10 of the resin layer 15. The fiber layer 14 may include the inorganic insulating particles 11 between the glass fibers 12.

  Further, the base body 7 is set to have a thickness of, for example, 0.1 mm to 1.0 mm, a thermal expansion coefficient in the plane direction is set to, for example, 4 ppm / ° C. to 15 ppm / ° C., and a thermal expansion coefficient in the thickness direction is set. For example, it is set to 11 ppm / ° C. or more and 30 ppm / ° C. or less, the thermal expansion coefficient in the thickness direction is set to, for example, 2 to 2.8 times the thermal expansion coefficient in the plane direction, and the Young's modulus is, for example, 20 GPa to 30 GPa. Is set to

  Here, the coefficient of thermal expansion of the substrate 7 is measured by a measuring method according to JISK7197-1991 using a commercially available TMA apparatus. The Young's modulus is measured using a Nano Indentor XP / DCM manufactured by MTS Systems.

  The resin 10 contained in the substrate 7 is, for example, epoxy resin, bismaleimide triazine resin, cyanate resin, polyparaphenylene benzbisoxazole resin, wholly aromatic polyamide resin, polyimide resin, aromatic liquid crystal polyester resin, polyether ether ketone resin or It can be formed of a resin material such as polyether ketone resin. The resin 10 has a coefficient of thermal expansion in the planar direction and thickness direction set to, for example, 20 ppm / ° C. or more and 50 ppm / ° C. or less, and a Young's modulus set to, for example, 3 GPa or more and 10 GPa or less.

  The inorganic insulating particles 11 coated with the resin 10 reduce the coefficient of thermal expansion of the base 7 and increase the rigidity of the base 7, and include an inorganic insulating material such as aluminum hydroxide, magnesium hydroxide, or silicon oxide, Among these, it is desirable to include silicon oxide having properties such as a coefficient of thermal expansion and Young's modulus that are close to those of glass fibers. As a result, the thermal expansion coefficient and Young's modulus of the resin layer 15 can be made closer to the fiber layer 14. When the inorganic insulating particles 11 contain silicon oxide, the inorganic insulating particles 11 desirably contain 65% by weight to 100% by weight of silicon oxide. In addition to silicon oxide, aluminum oxide, magnesium oxide, calcium oxide, nitriding You may contain aluminum, aluminum hydroxide, or calcium carbonate.

  The inorganic insulating particles 11 are formed in, for example, a spherical shape, the particle size is set to, for example, 0.5 μm or more and 5.0 μm or less, and the coefficient of thermal expansion in each direction is, for example, 2.7 ppm / ° C. or more and 6 ppm / ° C. or less. The Young's modulus is set to 70 GPa or more and 85 GPa or less. In addition, as the inorganic insulating particles 11, particles obtained by finely cutting glass fibers may be used.

  The inorganic insulating particles 11 are preferably set to have a content in the resin layer 15 of 40 volume% or more and 75 volume% or less. As a result, when the content of the inorganic insulating particles 11 is 40% by volume or more, the thermal expansion coefficient and Young's modulus of the resin layer 15 can be made closer to the fiber layer 14. Further, since the content of the inorganic insulating particles 11 is 70% by volume or less, the adhesive strength between the inorganic insulating particles 11 located on the inner wall of the through hole T and the resin 10 is increased, and the inorganic insulating particles 11 and the resin 10 Can be reduced, and as a result, peeling between the through-hole conductor 8 and the resin layer 15 can be reduced.

  Here, the particle diameter of the inorganic insulating particles 11 is measured by observing the cross section of the substrate 7 with a field emission electron microscope, measuring the maximum diameter of each particle, and calculating the average value. The content (volume%) of the inorganic insulating particles 11 in the resin layer 15 is determined by observing the cross section of the resin layer 15 with a field emission electron microscope, and the area ratio (area) occupied by the inorganic insulating particles 11 with respect to the resin layer 15. %), And the average value is calculated and regarded as the content (volume%).

  The base material 13 covered with the resin 10 increases the rigidity of the base body 7 and reduces the coefficient of thermal expansion in the plane direction. For example, a woven fabric in which a plurality of glass fibers 12 are woven vertically and horizontally is used. can do. In addition, you may use a nonwoven fabric as the base material 13, and you may use what arranged the some glass fiber 12 so that a longitudinal direction might become mutually parallel.

  The glass fiber 12 contained in the base material 13 can use a fiber made of glass such as T glass, S glass, or E glass, and the diameter of the cross section perpendicular to the longitudinal direction is set to 4 μm or more and 9 μm or less, for example. The coefficient of thermal expansion in the longitudinal direction and the width direction is set to 2.5 ppm / ° C. or more and 6 ppm / ° C. or less, and the Young's modulus is set to 70 GPa or more and 85 GPa or less.

  On the other hand, the through-hole conductor 8 attached to the inner wall of the through-hole T electrically connects the upper and lower wiring layers 6 to each other, and is formed of a conductive material such as copper, aluminum, or nickel, for example. It is desirable to use copper having high conductivity. The through-hole conductor 8 has a thickness from the inner wall of the through-hole T to the insulator 9 set to 3 μm or more and 20 μm or less, and the thermal expansion coefficient in the penetration direction and the width direction is, for example, 16 ppm / ° C. or more and 25 ppm / ° C. or less. For example, the Young's modulus is set to 60 GPa or more and 210 GPa or less. The thermal expansion coefficient of copper is about 18 ppm / ° C. Further, the thermal expansion coefficient and Young's modulus of the through-hole conductor 8 are measured in the same manner as the base body 7.

  An insulator 9 formed in a region surrounded by the through-hole conductor 8 forms a support surface of a via conductor 18 to be described later. For example, polyimide resin, acrylic resin, epoxy resin, cyanate resin, fluororesin, silicon It can be formed of a resin material such as resin, polyphenylene ether resin, or bismaleimide triazine resin.

  On the other hand, a pair of wiring layers 6 are formed on both sides of the core substrate 5 as described above. The wiring layer 6 is laminated on the base 7 and has an insulating layer 16 in which a via hole V penetrating in the thickness direction is formed, a conductive layer 17 formed on the base 7 or on the insulating layer 16, and the via hole V And a via conductor 18 electrically connected to the conductive layer 17.

  The insulating layer 16 not only functions as a support member that supports the conductive layer 17 but also functions as an insulating member that prevents a short circuit between the conductive layers 17. Resin and inorganic insulating particles coated with the resin , Including. The insulating layer 16 is set to have a thickness of, for example, 5 μm or more and 40 μm or less, a thermal expansion coefficient in a plane direction or a thickness direction is set to, for example, 15 ppm / ° C. or more and 45 ppm / ° C. or less, and a Young's modulus is, for example, 5 GPa or more and 40 GPa or less. Is set. The thermal expansion coefficient and Young's modulus of the insulating layer 16 are measured in the same manner as the substrate 7.

  Examples of the resin contained in the insulating layer 16 include epoxy resin, bismaleimide triazine resin, cyanate resin, polyparaphenylene benzbisoxazole resin, wholly aromatic polyamide resin, polyimide resin, aromatic liquid crystal polyester resin, and polyether ether ketone resin. Or what was formed with polyetherketone resin etc. can be used.

  As the inorganic insulating particles contained in the insulating layer 16, those similar to the inorganic insulating particles 11 contained in the substrate 7 can be used.

  The conductive layer 17 functions as, for example, a ground wiring, a power supply wiring, or a signal wiring. For example, a conductive layer 17 formed of a metal material such as copper, silver, gold, aluminum, nickel, or chromium is used. Can do. The conductive layer 17 has a thickness set to, for example, 3 μm or more and 20 μm or less, a coefficient of thermal expansion in the plane direction or the thickness direction, for example, set to 5 ppm / ° C. or more and 25 ppm / ° C. or less, and a Young's modulus set to 50 GPa or more and 250 GPa or less. Has been.

  The via conductor 18 connects the conductive layers 17 that are separated from each other in the thickness direction, and is formed in a tapered shape whose width decreases toward the core substrate 5, for example, copper, silver, gold, What was formed with the electrically conductive material of aluminum, nickel, or chromium can be used.

  By the way, since the glass fiber 12 has a smaller coefficient of thermal expansion than the through-hole conductor 8, when heat is applied to the wiring board 4, thermal stress is easily applied between the glass fiber 12 and the through-hole conductor 8.

  On the other hand, in the wiring board 4 of the present embodiment, as shown in FIG. 1B, the glass fiber 12 of the fiber layer 14 is a surface exposed on the inner wall of the through hole T (a surface parallel to the through direction of the through hole T). ) Has a groove-shaped (elongated shape) recess C, and a part of the through-hole conductor 8 is filled inside the recess C. Here, since the recessed part C is groove shape, the filling property of the through-hole conductor 8 to the recessed part C can be improved, and the anchor effect of the recessed part C and the through-hole conductor 8 can be improved. Therefore, the adhesive strength between the glass fiber 12 and the through-hole conductor 8 can be increased, and peeling between the glass fiber 12 and the through-hole conductor 8 can be reduced. As a result, disconnection of the through-hole conductor 8 can be reduced, and as a result, the wiring board 4 excellent in electrical reliability can be obtained.

  It is desirable that the length of the groove-like recess C in the longitudinal direction L is set to be 1.2 times or more and 2.5 times or less of the length in the width direction W. As a result, when the length in the longitudinal direction L is 1.2 times or more the length in the width direction W, the filling property of the through-hole conductor 8 into the concave portion C can be improved, and the length in the longitudinal direction L is increased. However, by being 2.5 times or less of the length in the width direction W, it is possible to suppress the length in the width direction W from becoming too small, and to secure the anchor effect to the through-hole conductor 8. The concave portion C has a length in the longitudinal direction L set to, for example, 3 μm to 8 μm, a length in the width direction W set to, for example, 2 μm to 5 μm, and a depth set to, for example, 0.5 μm to 3 μm. Has been.

  Moreover, as shown in FIG.1 (b), it is desirable for the recessed part C to be the groove shape along the thickness direction of the base | substrate 7. As shown in FIG. As a result, in the glass fiber 12 having a smaller amount of thermal expansion in plan view than the through-hole conductor 8, an anchor effect is generated in the circumferential direction of the through-hole T, and therefore the adhesive strength between the through-hole T inner wall and the through-hole conductor 8. Can be increased.

  The arithmetic average roughness (Ra) of the surface exposed to the inner wall of the through hole T of the glass fiber 12 is set to, for example, 0.3 μm or more and 3 μm or less. The arithmetic average roughness of the surface of the glass fiber 12 covered with the resin 10 (the surface not exposed to the inner wall of the through hole T) is set to 0.1 μm or less, for example, and the through hole T of the glass fiber 12 It is smaller than the arithmetic average roughness of the surface exposed on the inner wall. The arithmetic average roughness of the surface of the glass fiber 12 covered with the resin 10 is set to, for example, 10% or more and 50% or less of the arithmetic average roughness of the surface exposed to the inner wall of the through hole T of the glass fiber 12.

  Thus, the mounting structure 1 described above exhibits a desired function by driving or controlling the electronic component 2 based on the power supply and signals supplied via the wiring board 4.

  Next, the manufacturing method of the mounting structure 1 mentioned above is demonstrated based on FIG.

(Preparation of substrate)

(1) As shown in FIG. 2A, a copper clad laminate 5x comprising a base body 7 and copper foils 17x disposed above and below the base body 7 is prepared. Specifically, for example, it is performed as follows.

  First, a varnish containing uncured resin 10 and inorganic insulating particles 11 is prepared, and the base material 12 is impregnated with the varnish to form a resin sheet. Thus, when the base material 12 is impregnated with the varnish, the inorganic insulating particles 11 are less likely to enter between the glass fibers 12 of the base material 13, and thus are concentrated in a region outside the base material 13 (a region that becomes the resin layer 15). The The uncured state is an A-stage or B-stage according to ISO 472: 1999.

  Next, the resin sheet is laminated to form a substrate precursor, and a copper foil 17x is laminated on and under the substrate precursor to form a laminate, and then the laminate is heated and pressed in the thickness direction. Thus, the resin 10 is thermally cured to form the base 7 and the above-described copper-clad laminate 5x is produced. Thus, when forming the base | substrate 7, the resin between the base material 13 of the resin sheet and the glass fiber 12 becomes the fiber layer 14, and the regions outside the base material 13 of the adjacent resin sheets are bonded to each other to form the resin layer 15. It becomes.

(Through hole formation)

(2) As shown in FIG. 2B, through-holes T are formed in the copper-clad laminate 5x using a sandblast method. Specifically, for example, it is performed as follows.

  First, a resist having openings at the positions where the through holes T are formed is formed on both surfaces of the copper clad laminate 5x. This resist can be formed, for example, by exposure and development of a photosensitive resin. Next, a part (non-penetrating) of the through hole T is formed through the opening of the resist by injecting fine particles from the nozzle of the sand blasting device onto one main surface of the copper clad laminate 5x. Next, the through holes T penetrating the base 7 are formed by spraying fine particles onto the other main surface of the copper clad laminate 5x. Note that the through hole T penetrating the base body 7 may be formed by spraying fine particles only on one main surface of the copper clad laminate 5x. Next, the resist is removed with, for example, 1 to 3 wt% sodium hydroxide solution. Next, by washing the inner wall of the through hole T with high pressure water, the remaining fine particles and the processing waste of the through hole T are removed.

  Here, in the wiring substrate 4 of this embodiment, crushed fine particles (crushed particles) made of an inorganic insulating material having a hardness higher than that of glass can be used as fine particles to be ejected by sandblasting. As a result, the surface of the glass fiber 12 exposed on the inner wall of the through hole T is partially cut by the sharp end portion of the crushed particles harder than the glass fiber 12, so that the groove-shaped recess C along the thickness direction is cut. Can be formed.

  As the inorganic insulating material constituting the above-mentioned crushed particles, for example, alumina, silicon carbide, zirconia or the like can be used, and among these, it is desirable to use alumina. As the hardness, Vickers hardness can be used.

  Moreover, since sandblasting is performed using a resist, it is possible to process a plurality of through-holes T by spraying a wide range of fine particles, so the through-holes T can be formed more efficiently than drilling or laser processing. it can.

  Further, since the through hole T is formed by the fine particles, it is possible to reduce stress and heat applied to the boundary between the glass fiber 12 and the resin 10 (drilling heat of drilling) as compared with drilling. Compared with laser processing, heat applied to the boundary between the glass fiber 12 and the resin 10 can be reduced, so that peeling between the glass fiber 12 and the resin 10 can be reduced.

  Further, when the sandblasting method is used, when the content of the inorganic insulating filler 11 in the substrate 7 is increased, the drill is not worn like the drilling process, and the through hole T can be formed more easily than the laser processing. Can be formed.

  As described above, since the through hole T and the concave portion C are formed by the sand blast method, the sand blast method can be performed under the following conditions.

  First, the sandblasting method is performed by drive last. As a result, since resistance to fine particles is small compared to wet blasting, it is possible to improve the machinability of the through-hole T, reduce the residual machining waste during cutting, and reduce the cutting hindrance due to the machining waste.

  Moreover, the maximum diameter of the fine particles is set to 3 μm or more and 40 μm or less. As a result, by setting the maximum diameter to 3 μm or more, it is possible to easily form the through hole T by improving the cutting performance by the crushed particles. Further, by setting the maximum diameter to 40 μm or less, the through hole T can be formed without crushing the crushed particles.

  Moreover, it is desirable that the pressure for injecting the fine particles is set to 0.15 MPa or more and 0.22 MPa or less. As a result, the glass fiber 12 in the through hole T can be efficiently cut by setting the pressure to 0.15 MPa or more. Further, by setting the pressure to 0.22 MPa or less, it is possible to process so that the crushed particles collide with each other and the resin 10 on the inner wall of the through hole T is not excessively cut.

  Moreover, it is desirable that the injection amount of the fine particles is set to 30 g / min or more and 200 g / min or less. As a result, the glass fiber 12 in the through hole T can be efficiently cut by setting the injection amount to 30 g / min or more. Further, by setting the injection amount to 200 g / min or less, it is possible to process so that the crushing particles collide with each other and the resin 10 on the inner wall of the through hole T is not excessively cut.

  In addition, the number of times the fine particles are ejected to one through hole T (the number of scans) is set to, for example, 4 to 20 times when the thickness of the core substrate 5 is 40 to 200 μm.

  Further, the resin layer 15 of the base body 7 on which the fine particles are injected has the content of the inorganic insulating particles 11 set to 40% by volume or more and 75% by volume or less. As a result, by making the content of the inorganic insulating particles 11 40% by volume or more, the machinability of the resin layer 15 by the sandblast method can be improved. In addition, by setting the content of the inorganic insulating particles 11 to 75% by volume or less, the formation of the through holes T reduces the degranulation of the inorganic insulating particles 11 from the inner walls of the through holes T, and the dents caused by the degranulation It can be reduced that the bubbles remain and the adhesion strength between the inner wall of the through hole T and the through hole conductor 8 is lowered.

  Here, it is desirable that the inner wall of the through hole T formed by the sandblast method is not subjected to desmear treatment. When the through-hole T is formed by the sand blast method, the heat applied to the inner wall of the through-hole T can be reduced to reduce the residue of the carbonized resin as compared with drilling or laser processing, and physically between the molecules. Since the bond is cut, the reaction activity of the surface of the resin 10 exposed on the inner wall of the through hole T can be increased. Further, as described above, an anchor effect with the through-hole conductor 8 is generated by the concave portion C of the glass fiber 12 exposed on the inner wall of the through-hole T. Therefore, the adhesive strength between the inner wall of the through hole T and the through hole conductor 8 can be increased without performing a desmear process. By not performing the desmear process in this way, it is possible to reduce only the resin 10 from being selectively etched and to largely expose the side surfaces of the glass fibers 12, and to reduce the peeling between the resin 10 and the glass fibers 12.

(Formation of through-hole conductors)

(3) As shown in FIG. 2C, the through-hole conductor 8, the insulator 9 and the conductive layer 17 are formed on the base body 7, and the core substrate 5 is manufactured. Specifically, for example, it is performed as follows.

  First, a cylindrical through-hole conductor 8 is formed by depositing a conductive material on the inner wall of the through-hole T by, for example, electroless plating, electrolytic plating, vapor deposition, CVD, or sputtering. At this time, the conductive material is filled in the recess C of the inner wall of the through hole T. Here, since the recessed part C is groove-shaped, it can reduce that a bubble remains in the recessed part C at the time of conductive material deposition, and can improve the filling property of the electrically-conductive material with respect to the recessed part C.

  Next, a region surrounded by the cylindrical through-hole conductor 8 is filled with a resin material or the like to form an insulator 9. Next, after a conductive material is deposited on the exposed portion of the insulator 9, the copper foil 17x is patterned by a conventionally known photolithography technique, etching, or the like to form the conductive layer 17.

  The core substrate 5 can be manufactured as described above.

(Formation of wiring layer)

(4) As shown in FIG. 2 (d), the wiring substrate 4 is manufactured by forming a pair of wiring layers 6 on both sides of the core substrate 5. Specifically, for example, it is performed as follows.

  First, an uncured resin is placed on the conductive layer 17, and the resin is heated and fluidly adhered, and further heated to cure the resin, thereby forming the insulating layer 16 on the conductive layer 17. Next, a via hole V is formed by laser processing, and at least a part of the conductive layer 17 is exposed in the via hole V. Thus, by forming the via hole V by laser processing, damage to the conductive layer 17 exposed in the via hole V can be reduced as compared with the sandblasting method. Next, the via conductor 18 is formed in the via hole V and the conductive layer 17 is formed on the upper surface of the insulating layer 16 by, for example, a semi-additive method, a subtractive method, or a full additive method.

  The wiring board 4 can be produced as described above. By repeating this process, the insulating layer 16 and the conductive layer 17 can be multilayered in the wiring layer 6.

(Electronic component mounting)

(5) The bump 3 is formed on the upper surface of the uppermost conductive layer 17 and the electronic component 2 is flip-chip mounted on the wiring board 4 via the bump 3.

  As described above, the mounting structure 1 shown in FIG. 1A can be manufactured.

  The present invention is not limited to the above-described embodiments, and various modifications, improvements, combinations, and the like can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the configuration using a semiconductor element as an electronic component has been described as an example, but a capacitor or the like may be used as the electronic component.

  In the above-described embodiment, the configuration in which the electronic component is flip-chip mounted on the wiring board has been described as an example. However, the electronic component may be mounted on the wiring board by wire bonding, or the electronic component may be mounted inside the wiring board. May be implemented.

  In the above-described embodiment, the configuration in which the wiring layer includes one insulating layer has been described as an example. However, the wiring layer may include any number of insulating layers.

  In the above-described embodiment, the configuration in which the base includes three fiber layers has been described as an example. However, the base may include any number of fiber layers.

  In the above-described embodiment, the configuration in which the resin of the fiber layer and the resin of the resin layer are the same is described as an example, but the resin of the fiber layer and the resin of the resin layer may be different.

  Moreover, in embodiment mentioned above, although the structure using copper foil was demonstrated to the example in the process of (1), the metal which consists of metal materials, such as an iron nickel alloy or an iron nickel cobalt alloy, for example instead of copper foil A foil may be used.

DESCRIPTION OF SYMBOLS 1 Mounting structure 2 Electronic component 3 Bump 4 Wiring board 5 Core board 6 Wiring layer 7 Base body 8 Through-hole conductor 9 Insulator 10 Resin 11 Inorganic insulating particle 12 Glass fiber 13 Base material 14 Fiber layer 15 Resin layer 16 Insulating layer 17 Conductivity Layer 18 Via conductor T Through hole V Via hole C Recess

Claims (5)

A base, a through-hole penetrating the base in the thickness direction, and a through-hole conductor covering the inner wall of the through-hole;
The base has a plurality of glass fibers and a resin disposed between the plurality of glass fibers,
The inner wall of the through hole is formed by a cutting surface in which the glass fiber and the resin are cut by blasting,
The glass fiber has a groove-like recess on the cutting surface,
The wiring board, wherein the recess is filled with a part of the through-hole conductor. The wiring board according to claim 1,
The wiring board according to claim 1, wherein a longitudinal direction of the recess is along a thickness direction of the base. The wiring board according to claim 1,
The length of the recess in the longitudinal direction is 1.2 to 2.5 times the length of the recess in the width direction. The wiring board according to claim 1,
The wiring substrate according to claim 1, wherein the glass fiber has an arithmetic average roughness of a surface exposed to the inner wall of the through hole of 0.3 μm to 3 μm. The wiring board according to claim 1;
A mounting structure comprising: an electronic component mounted on the wiring board and electrically connected to the through-hole conductor.

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