JP5127622B2 - Wiring board, mounting structure, and manufacturing method of wiring board - Google Patents

Description

  The present invention relates to a wiring board used for an electronic device, a mounting structure in which an electronic component is mounted on the wiring board, and a method for manufacturing the wiring board. Such electronic devices are various audio-visual devices, home appliances, communication devices, computer devices or peripheral devices thereof.

  2. Description of the Related Art Conventionally, a wiring board on which an electronic component such as a semiconductor element such as an IC (Integrated Circuit) or LSI (Large Scale Integration) or a capacitor is mounted is known.

  The wiring board includes a first conductive layer, an insulating layer positioned on the first conductive layer, a second conductive layer positioned on the insulating layer, and a first conductive layer formed in the insulating layer. A configuration including a via conductor that connects the second conductive layer is known. Regarding the via conductor, Patent Document 1 describes a via conductor in which the cross-sectional area of the central portion is smaller than the cross-sectional areas of the upper part and the lower part.

By the way, since the insulating layer has a higher thermal expansion coefficient than the via conductor, when heat is applied to the wiring board due to heating of solder reflow or heat generation of the electronic part when the electronic component is mounted on the wiring board, the insulating layer Greatly expands in the vertical direction compared to the via conductor. On the other hand, the insulating layer is in contact with both the first conductive layer and the second conductive layer, and the via conductor is connected to both the first conductive layer and the second conductive layer. Therefore, due to thermal expansion in the vertical direction of the insulating layer, the first conductive layer formed on the upper surface of the insulating layer is pressed upward, and the second conductive layer formed on the lower surface of the insulating layer is pressed downward, respectively. Due to the pressing force, a vertical tensile stress is applied to the via conductor. Since such tensile stress tends to concentrate on the central portion of the via conductor, a crack is generated in the via conductor at the central portion, and the electrical reliability of the wiring board tends to be lowered.
JP 2006-253189 A

  For this reason, it is required to disperse the stress in the via conductor satisfactorily, and the present invention provides a wiring board, a mounting structure, and a manufacturing method of the wiring board that meet such a demand.

  A wiring board according to an embodiment of the present invention is provided on a first conductive layer having a base layer and a protruding portion protruding from the upper surface of the base layer, and on the first conductive layer so as to cover the base layer and the protruding portion. An insulating layer, a second conductive layer located on the insulating layer, and a via conductor formed in the insulating layer and connecting the protruding portion of the first conductive layer and the second conductive layer. The protruding portion of the layer has a protruding portion that protrudes from the upper side surface in a direction along the upper surface of the underlayer and that is separated from the upper surface of the underlayer via the insulating layer, and between the via conductor and the protruding portion. In addition, a corner portion that is depressed is provided between the projecting portion and the projecting portion below the projecting portion.

  A mounting structure according to an embodiment of the present invention includes a first conductive layer having a base layer and a protruding portion protruding from an upper surface of the base layer, and the first conductive layer so as to cover the base layer and the protruding portion. A wiring board comprising: an insulating layer positioned; a second conductive layer positioned on the insulating layer; and a via conductor formed in the insulating layer and connecting the protruding portion of the first conductive layer and the second conductive layer And an electronic component mounted on the wiring board and electrically connected to the first conductive layer and the second conductive layer, and the protruding portion of the first conductive layer extends from the upper side surface to the upper surface of the base layer. And a projecting portion extending between the via conductor and the projecting portion, and below the projecting portion and the projecting portion. It is characterized by having a recessed corner part.

According to one aspect of the present invention, there is provided a method of manufacturing a wiring substrate, comprising: preparing a first conductive layer having a base layer and a protruding portion protruding from an upper surface of the base layer; and covering the base layer and the protruding portion. Forming the insulating layer on the first conductive layer, forming a via hole in the insulating layer, exposing a part of the protrusion in the via hole, and in the via hole A step of forming a via conductor connected to the protrusion and a step of forming a second conductive layer connected to the via conductor on the insulating layer, and the step of preparing the first conductive layer includes the steps of: Preparing a foundation layer; forming a resist layer on the foundation layer; forming the protrusion on the foundation layer exposed between the resist layers; removing the resist layer; And in the step of forming the protrusion, As part is formed on the upper surface of the resist layer, and forming the protrusion.

  According to the wiring board, the mounting structure, and the manufacturing method of the wiring board according to one aspect of the present invention, the stress applied to the via conductor can be dispersed. As a result, a wiring board and a mounting structure excellent in electrical reliability can be obtained.

  Hereinafter, a mounting structure including a wiring board according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2.

  A mounting structure 1 shown in FIGS. 1 and 2 includes a wiring board 2 and an electronic component 4 flip-chip mounted on the upper surface of the wiring board 2 via bumps 3.

  The wiring board 2 includes a base 5, a plurality of insulating layers 6 stacked on the top and bottom surfaces of the base 5, and a plurality of conductive layers 7 disposed on the top and bottom surfaces of the insulating layer 6. Yes.

  Further, the base 5 is formed with a through hole S penetrating in the vertical direction (Z direction). A through-hole conductor 8 is formed on the inner wall of the through-hole S. The through-hole conductor 8 electrically connects the conductive layers 7 formed on the upper surface and the lower surface of the base body 5. The through-hole conductor 8 is made of a conductive material. The conductive material includes, for example, copper, silver, nickel, chromium, or the like. In the present embodiment, the through-hole conductor 8 is formed in a cylindrical shape, and the cylindrical body is filled with an insulator 9 in order to ensure the flatness of the base 5. The insulator 9 includes a resin material, a filler, an elastomer, a flame retardant, a curing agent, and the like. For example, an epoxy resin or a cyanate resin is used as the resin material. As the filler, for example, silicon oxide or aluminum oxide is used. As the elastomer, a styrene elastomer or a polyester elastomer is used.

  The insulating layer 6 has an adhesive layer 6a and a resin layer 6b.

  The adhesive layer 6a is for firmly bonding the resin layers 6b to each other or the resin layer 6b and the substrate 5, and includes a thermosetting resin or a thermoplastic resin. As the thermosetting resin, for example, at least one of polyimide resin, acrylic resin, epoxy resin, urethane resin, cyanate resin, silicon resin, and bismaleimide triazine resin can be used. As the thermoplastic resin, since it is necessary to have heat resistance that can withstand the heating during solder reflow, the softening temperature of the constituent material is desirably 200 ° C. or higher, and for example, a liquid crystal polymer or the like can be used. The thermal expansion coefficient of the adhesive layer 6a is preferably set to 15 ppm / ° C. or more and 80 ppm / ° C. or less, for example. Moreover, it is desirable that the adhesive layer 6a is set to have a thickness of, for example, 2 μm or more and 20 μm or less.

  The resin layer 6b is for improving the mechanical strength of the wiring board 2, and does not include a base material, and preferably contains a thermosetting resin or a thermoplastic resin. As the thermosetting resin or thermoplastic resin, it is desirable to use a material that is elastically deformable and has excellent heat resistance and hardness. As the thermosetting resin having such characteristics, for example, polyimide benzoxazole resin, polyparaphenylene benzbisoxazole resin, wholly aromatic polyamide resin, or wholly aromatic polyester resin can be used. Moreover, as a thermoplastic resin, a thermoplastic polyimide resin or a liquid crystal polymer resin etc. can be used, for example. Among the above materials, it is desirable to use polyimide benzoxazole resin or polyparaphenylene benzbisoxazole resin. The polyparaphenylene benzbisoxazole resin has a low coefficient of thermal expansion of −5 ppm / ° C. to 5 ppm / ° C. By using such a low thermal expansion resin, the thermal expansion coefficient of the wiring board 2 can be brought close to the thermal expansion coefficient of the electronic component 4, and the thermal stress between the wiring board 2 and the electronic component 4 is reduced. be able to. The thickness of the resin layer 6b is preferably set to be 2 μm or more and 20 μm or less, for example.

  A via hole V is formed in the insulating layer 6, and a via conductor 10 is formed in the via hole V. The via conductor 10 is connected to the conductive layer 7 disposed on the upper and lower surfaces of the insulating layer 6. The via conductor 10 is formed so that the cross-sectional area increases from the upper surface of the base body 5 toward the upper surface of the wiring board 2 or from the lower surface of the base body 5 toward the lower surface of the wiring board 2, for example. The via conductor 10 is formed of a conductive material. The conductive material includes, for example, copper, silver, gold, aluminum, nickel, or chromium. The thermal expansion coefficient of the via conductor 10 is desirably set to, for example, 12 ppm / ° C. or more and 20 ppm / ° C. or less. In addition, a cross-sectional area means the area of the cross section to a plane direction (XY plane direction).

  The via conductor 10 located on the upper surface side of the wiring board 2 is preferably closer to the center of the plane (XY plane) of the wiring board 2 than the via conductor 10 located on the lower surface side. As a result, the wiring density on the upper surface side of the wiring board 2 on which the electronic component 4 is mounted can be made higher than the wiring density on the lower surface side of the wiring board 2 connected to the external circuit. It becomes possible to mount a small electronic component 4 on the surface.

  The conductive layer 7 includes a signal layer that transmits an electrical signal and a ground layer that is connected to the electronic component 4. The conductive layer 7 is formed of a conductive material. The conductive material includes, for example, copper, silver, gold, nickel, chromium, titanium, molybdenum, tungsten, zirconium, or an alloy thereof. The coefficient of thermal expansion of the conductive layer 7 is desirably set to 12 ppm / ° C. or more and 20 ppm / ° C. or less, for example.

  The electronic component 4 is electrically connected to the conductive layer 7 via the bump 3. A conductive material is used for the material of the bump 3. For example, copper, silver, zinc, tin, indium, bismuth, or antimony may be used as the conductive material. The electronic component 4 may use a semiconductor element or a capacitor. For example, an IC or an LSI may be used as the semiconductor element. As a material of the semiconductor element, silicon, germanium, gallium arsenide, gallium arsenide phosphorus, gallium nitride, silicon carbide, or the like may be used. The thickness of the electronic component 4 is desirably 0.1 mm to 1 mm, for example.

  Next, the configuration of the conductive layer 7 will be described in more detail.

  As shown in FIG. 3, the conductive layer 7 includes a first conductive layer 7 a formed on the lower surface of the insulating layer 6, and a second conductive layer 7 b formed of the conductive layer 7 formed on the upper surface of the insulating layer 6. . The first conductive layer 7a includes a flat base layer 7ax and a protruding portion 7ay protruding from the upper surface of the base layer 7ax.

  The protruding portion 7ay is interposed between the via conductor 10 and the base layer 7ax, and is connected to the via conductor 10. Further, the protruding portion 7ay has, on the upper side surface thereof, an overhanging portion 7az that protrudes from the side surface in a direction along the upper surface of the base layer 7ax (XY plane direction). An insulating layer 6 is interposed in a region between the projecting portion 7az and the base layer 7ax, and the projecting portion 7az is separated from the base layer 7ax through the insulating layer 6. A part of the protruding portion 7ay located below the projecting portion 7az is a columnar portion 7aw.

  Thus, in the wiring board 2 of the present embodiment, the via conductor 10 is connected to the projecting portion 7ay, and the projecting portion 7ay has an overhang portion 7az. Therefore, the side surface between the via conductor 10 and the projecting portion 7ay and the side surface between the projecting portion 7az and the columnar portion 7aw form a discontinuous surface toward the inside of the via conductor 10 or the projecting portion 7ay. A recessed corner 7av is formed. That is, in the wiring board 2 of the present embodiment, constrictions are formed between the via conductor 10 and the protruding portion 7ay and between the projecting portion 7az and the columnar portion 7aw. The corner 7av includes a first corner 7av1 located between the via conductor 10 and the overhang 7az, and a second corner 7av2 located between the overhang 7az and the columnar portion 6w. As a result, the stress applied when the insulating layer 6 is thermally expanded is dispersed in the first corner portion 7av1 and the second corner portion 7av2, reducing the possibility of cracks occurring in the via conductor 10 and the protruding portion 7ay, The electrical reliability of the wiring board 2 can be increased.

  The insulating layer 6 is present between the second conductive layer 7b and the overhanging portion 7az and between the overhanging portion 7az and the first conductive layer 7a. Thus, when the insulating layer 6 located between the second conductive layer 7b and the overhanging portion 7az is thermally expanded, the second conductive layer 7b is pressed upward and the overhanging portion 7az is pressed downward. Further, when the insulating layer 6 located between the overhanging portion 7az and the first conductive layer 7a is thermally expanded, the overhanging portion 7az is pressed upward and the second conductive layer 7az is pressed downward. As a result, when the insulating layer 6 is thermally expanded, the stress applied to the via conductor 10 and the protruding portion 7ay is positioned below the protruding portion 7az and the via conductor 10 and the protruding portion 7ay located above the protruding portion 7az. It can disperse | distribute to the columnar part 7aw.

  The thickness of the foundation layer 7ax is preferably set to 3 μm or more and 12 μm or less. Further, it is desirable that the protruding length of the protruding portion 7ay is set to 3 μm or more and 16 μm or less. The height of the columnar portion 7aw is preferably set to 2 μm or more and 15 μm or less, and the width of the columnar portion 7aw is preferably set to 30 μm or more and 100 μm or less. Further, it is desirable that the overhanging length of the overhanging portion 7az is set to 0.3 μm or more and 5 μm or less, and the thickness of the overhanging portion 7az is set to 0.3 μm or more and 3 μm or less. Further, it is desirable that the width of the connection portion between the via conductor 10 and the protruding portion 6by is set to 5 μm or more and 30 μm or less, and the length of the via conductor 10 in the vertical direction is set to 3 μm or more and 25 μm or less. The width refers to the length in the plane direction (XY plane direction).

  Further, the upper surface of the projecting portion 7az is the lower surface of the second conductive layer 7b so that the distance between the lower surface of the second conductive layer 7b and the upper surface of the projecting portion 7az increases in the direction in which the projecting portion 7az projects. It is desirable to be inclined with respect to. In this case, when the insulating layer 6 located between the second conductive layer 7b and the overhanging portion 7az thermally expands in the vertical direction and the upper surface of the overhanging portion 7az is pressed downward, a part of the pressing force is overhanging. It is transmitted toward the tip of the part 7a. As a result, the stress applied to the via conductor 10 and the protrusion 7ay can be reduced.

  Further, it is desirable that the second corner portion 7av2 positioned between the projecting portion 7az and the columnar portion 7aw has a curved surface. As a result, the stress applied to the second corner portion 7av2 can be dispersed within the second corner portion 7av. In addition, it is desirable for the curved surface to have a radius of an inscribed circle of 0.2 μm or more and 2 μm or less when viewed in a cross section in the vertical direction.

  Further, it is desirable that the cross-sectional area of the columnar portion 7aw of the projecting portion 7ay decreases from the base layer 7ax toward the projecting portion 6ay. As a result, the second corner 7av2 can be sharply cut into the protrusion 7ay, and the stress applied to the via conductor 10 and the protrusion 7ay can be increased in the second corner 7av2. In addition, as for columnar part 7aw, it is desirable for the width | variety of the edge part by the side of base layer 7ax to be 1.1 times or more larger than 1 time of the width | variety of the edge part by the side of the overhang | projection part 6ay.

  Further, it is desirable that the overhanging portion 7az is provided over the entire circumference of the protruding portion 7ay. As a result, the region where the projecting portion 7az is formed in the protruding portion 7ay increases, and the distribution of the stress applied to the via conductor 10 and the protruding portion 7ay to the second corner portion 7av2 can be increased.

  As described above, according to the present embodiment, the stress applied to the via conductor 10 and the protruding portion 7ay can be dispersed by forming the protruding portion 7az on the protruding portion 7ay of the first conductive layer 7a. The possibility that a crack is generated in the conductor 10 and the protruding portion 7ay can be reduced, and the electrical reliability of the wiring board 2 can be increased.

  Next, a method for manufacturing the mounting structure 1 including the above-described wiring board 2 will be described with reference to FIGS.

  (1) As shown in FIG. 4A, a substrate 5 is prepared. Specifically, after preparing a plurality of resin sheets in which a base material is impregnated with a thermosetting resin, the base sheets 5 are prepared by laminating those resin sheets and applying heat and pressure. The thickness of the base 5 is preferably set to, for example, 0.3 mm or more and 1.5 mm or less.

  (2) As shown in FIG. 4B, a through hole S penetrating in the vertical direction is formed in the base 5. The through hole S is formed by, for example, drilling or laser processing. Further, it is desirable that several through holes S are formed. Further, it is desirable that the width of the through hole S is set to, for example, 0.1 mm or more and 1 mm or less.

  (3) As shown in FIG. 4C, a conductive material is deposited on the surface of the base 5 to form a conductive material layer 7w. The conductive material layer 7 w forms a cylindrical through-hole conductor 8 on the inner wall surface of the through-hole S. The conductive material layer 7w is formed by, for example, an electroless plating method.

  (4) As shown in FIG. 5A, the inside of the cylindrical through-hole conductor 8 is filled with a resin material or the like to form an insulator 9.

  (5) As shown in FIG. 5B, a conductive material is deposited on the exposed portion of the insulator 9 to form a conductive material layer 7 w on the exposed portion of the insulator 9. Such a conductive material is deposited by, for example, electroless plating, vapor deposition, CVD, or sputtering.

  (6) As shown in FIG. 5C, the conductive material layer 7w is patterned to form a base layer 7ax. The patterning of the conductive material layer 7w is performed using a conventionally known photolithography technique or the like.

  (7) As shown in FIGS. 6A and 6B, a resist layer 11 having an opening O is formed on the base layer 7ax. Here, for example, when a photosensitive resin is used as the resist layer 11, the cross-sectional area of the opening O between the resist layers 11 is increased from the lower part of the resist layer 11 by reducing the amount of light when the resist layer 11 is exposed. The resist layer 11 can be formed so as to become smaller toward. As a result, the cross-sectional area of the protrusion 7ay can be reduced upward from the base layer 7ax.

  Further, when a photosensitive resin is used as the resist layer 11, when developing the resist layer 11, the side surface of the resist layer 11 exposed to the opening O and the resist are ejected by spraying a developer at a pressure of 0.2 MPa or more. The surface of the corner 11a between the upper surface of the layer 11 can be a curved surface. As a result, when the protrusion 7ay is formed, the surface of the corner 7av of the protrusion 7ay can be a curved surface. As such a developer, for example, a meta-sodium silicate aqueous solution or a sodium carbonate aqueous solution may be used.

  (8) As shown in FIGS. 7A and 7B, a conductive material is deposited on the surface of the base layer 7ax exposed from the openings O between the resist layers 11, thereby forming the protrusions 7ay on the base layer 7ax. . Such a conductive material is applied by an electroless plating method or an electroplating method.

  Here, as shown in FIGS. 8A and 8B, the protruding portion 7ay is formed to be higher than the height of the upper surface of the resist layer 11, and as shown in FIGS. 9A and 9B, the protruding portion 7ay is formed. When a part of the resist layer 11 is deposited on the upper surface of the resist layer 11, an overhang 7 az can be formed on the upper surface of the resist layer 11.

  (9) As shown in FIG. 10A, the resist layer 11 is removed. The removal of the resist layer 11 is performed, for example, by immersing the resist layer 11 in an aqueous sodium hydroxide solution or the like.

  (10) As shown in FIG. 10B and FIG. 11A, a film-like resin layer 6b and an adhesive layer 6a are formed on the first conductive layer 7a so that the adhesive layer 6a covers the base layer 7ax and the protruding portion 7ay. Paste through. The bonding is performed by heating and pressing using, for example, a heating press. In this way, the insulating layer 6 composed of the adhesive layer 6a and the resin layer 6b can be formed on the first conductive layer 7a.

  (11) As shown in FIG. 11B, a via hole V is formed in the insulating layer 6, and a part of the protruding portion 7 ay is exposed in the via hole V. Specifically, by using, for example, a YAG laser device or a carbon dioxide laser device, the insulating layer 6 positioned immediately above the projecting portion 7ay is irradiated with laser light until a part of the projecting portion 7ay is exposed. A via hole V is formed.

  Here, since the insulating layer 6 is formed such that the region located immediately above the protruding portion 7ay is thinner than the other region, the protruding portion 7ay protrudes, so that the via hole is formed. The length of V in the vertical direction is shortened, and the irradiation time of laser light can be shortened. As a result, the time for forming the via hole V can be shortened. Moreover, since the thickness of the first conductive layer 7a at the protruding portion 7ay is thick, the first conductive layer 7a has improved durability against laser light irradiation at the protruding portion 7ay. As a result, the via hole V can be formed using a high-power laser beam, and the time required for forming the via hole V can be shortened.

  Further, the via hole V formed by laser light irradiation may become narrower from the top to the bottom. In this case, the width of the connection portion between the first conductive layer 7a and the via conductor 10 formed in the via hole V is narrowed. However, in the present embodiment, since the thickness of the insulating layer 6 in the laser light irradiation region is thin, the width of the via conductor 10 at the connection portion with the protruding portion 7ay can be increased. As a result, the stress concentrated on the connection portion between the first conductive layer 7a and the via conductor 10 can be reduced.

  (12) As shown in FIG. 12A, the via conductor 10 connected to the protruding portion 7ay is formed in the via hole V, and the second conductive layer 7b connected to the via conductor 10 is further formed on the upper surface of the resin layer 6b. To do. The via conductor 10 and the second conductive layer 7b are formed by a conventionally well-known semi-additive method, subtractive method, full-additive method, or the like.

  Here, since the via hole V is formed by the laser beam, foreign matter may adhere to the surface of the protruding portion 7ay exposed in the via hole V. When the via conductor 10 is formed in such a protruding portion 7ay shape, bubbles or foreign matter may be included between the protruding portion 7ay and the via conductor 10. Therefore, the interface between the protruding portion 7ay and the via conductor 10 can be easily found by observing the bubbles or the foreign matters by microscopic observation. Microscopic observation is performed by polishing a cross section of the cut wiring board 2 in a mirror state and observing the cross section using a scanning electron microscope or the like. Further, when the protrusions 7ay and the via conductors 10 are formed differently, the crystal structures of the protrusions 7ay and the via conductors 10 are different, so that the interface between the protrusions 7ay and the via conductors 10 can be easily found. For example, when the protrusion 7ay is formed by electroplating and then plated on the surface of the protrusion 7ay exposed in the via hole V by electroless plating, the via conductor 10 is electrolessly plated. Since the formed portion is different in crystal state from the protruding portion 6av, the interface between the protruding portion 7ay and the via conductor 10 can be easily found by the above-described microscopic observation.

  (13) As shown in FIG. 12B, the second conductive layer 7b formed on the surface of the resin layer 6b is used as the base layer 7ax of the first conductive layer 7a, and the protruding portion 7ay is formed on the base layer 7ax. The protrusion 7ay is formed on the base layer 7ax by the same process as the processes (7) to (9).

  (14) As shown in FIG. 13A, FIG. 13B, and FIG. 14A, the insulating layer 6 is formed on the first conductive layer by the same steps as the steps (10) to (12), and via holes are formed in the insulating layer 6. V is formed, and at least a part of the protruding portion 7ay is exposed in the via hole V. Next, the via conductor 10 connected to the protruding portion 7ay is formed in the via hole V, and the second conductive layer 7b connected to the via conductor 10 is formed on the upper surface of the resin layer 6b.

  As described above, the multilayer wiring substrate 2 can be manufactured. In addition, by repeating the steps (13) and (14), the wiring board 2 can be further multilayered.

  (15) As shown in FIG. 14B, the mounting structure 1 can be manufactured by flip-chip mounting the electronic component 4 on the wiring board 2 via the bumps 3.

  In addition, this invention is not limited to the above-mentioned form, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention. For example, in the above-described embodiment of the present invention, the configuration in which the insulating layer 6 formed on the upper surface and the lower surface of the substrate 5 is two layers has been described, but the insulating layer 6 may be one layer or three or more layers. Absent.

  Moreover, although embodiment of this invention mentioned above demonstrated regarding the structure in which the insulating layer 6 had the contact bonding layer 6a and the resin layer 6b, the insulating layer 6 may be the structure which consists only of the contact bonding layer 6a. In this case, in the step (10), instead of laminating the film-like resin layer 6b on the first conductive layer 7a via the adhesive layer 6a, only the adhesive layer 6a is bonded to the first conductive layer 7a. On the conductive layer 7a, the insulating layer 6 made of only the adhesive layer 6a can be formed.

  In addition, the above-described embodiment of the present invention has been described with respect to the manufacturing method in which the protrusion 7ay is formed on the base layer 7ax of the first conductive layer 7a in the steps (7) to (9) and (13). However, the protruding portion 7ay may be formed on the base layer 7ax of the first conductive layer 7a only in any one of the steps (7) to (9) or (13).

It is a top view of the mounting structure concerning the embodiment of the present invention. It is sectional drawing of the mounting structure concerning embodiment of this invention. FIG. 3 is an enlarged view of an X1 portion of the mounting structure shown in FIG. 2. 4A, 4B, and 4C are cross-sectional views illustrating a manufacturing process of the mounting structure shown in FIG. 5A, 5B, and 5C are cross-sectional views illustrating a manufacturing process of the mounting structure shown in FIG. 6A is a cross-sectional view illustrating a manufacturing process of the mounting structure shown in FIG. 2, and FIG. 6B is an enlarged view of a portion X2 illustrating the manufacturing process of the mounting structure shown in FIG. 6A. 7A is a cross-sectional view illustrating a manufacturing process of the mounting structure shown in FIG. 2, and FIG. 7B is an enlarged view of a portion X3 illustrating the manufacturing process of the mounting structure shown in FIG. 7A. 8A is a cross-sectional view illustrating a manufacturing process of the mounting structure shown in FIG. 2, and FIG. 8B is an enlarged view of a portion X4 illustrating the manufacturing process of the mounting structure shown in FIG. 8A. 9A is a cross-sectional view illustrating a manufacturing process of the mounting structure shown in FIG. 2, and FIG. 9B is an enlarged view of a portion X5 illustrating the manufacturing process of the mounting structure shown in FIG. 9A. 10A and 10B are cross-sectional views illustrating a manufacturing process of the mounting structure shown in FIG. 11A and 11B are cross-sectional views illustrating a manufacturing process of the mounting structure shown in FIG. 12A and 12B are cross-sectional views illustrating a manufacturing process of the mounting structure shown in FIG. 13A and 13B are cross-sectional views illustrating a manufacturing process of the mounting structure shown in FIG. 14A and 14B are cross-sectional views illustrating a manufacturing process of the mounting structure shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mounting structure 2 Wiring board 3 Bump 4 Electronic component 5 Base body 6 Insulating layer 6a Adhesive layer 6b Film layer 7 Conductive layer 7a First conductive layer 7ax Base layer 7ay Projection part 7az Overhang part 7av Corner part 7aw Columnar part 7b Second conductive part Layer 7w Conductive material layer 8 Through-hole conductor
9 Insulator 10 Via Conductor 11 Resist Layer S Through Hole V Via Hole
O opening

Claims (6)

A first conductive layer having an underlayer and a protruding portion protruding from the upper surface of the underlayer;
An insulating layer located on the first conductive layer so as to cover the base layer and the protrusion; and
A second conductive layer located on the insulating layer;
A via conductor formed in the insulating layer and connecting the protruding portion of the first conductive layer and the second conductive layer; and
The projecting portion of the first conductive layer has a projecting portion that projects from the upper side surface in a direction along the upper surface of the base layer and is spaced from the upper surface of the base layer via the insulating layer,
A wiring board having a recessed corner portion between the via conductor and the overhanging portion and between the overhanging portion and the protruding portion below the overhanging portion. The wiring board according to claim 1,
The upper surface of the projecting portion is larger than the lower surface of the second conductive layer so that the distance between the lower surface of the second conductive layer and the upper surface of the projecting portion increases in the projecting direction of the projecting portion. A wiring board characterized by being inclined. The wiring board according to claim 1,
The wiring board, wherein the corner portion located between the projecting portion and the projecting portion below the projecting portion has a curved surface. The wiring board according to claim 1,
The wiring board according to claim 1, wherein a cross-sectional area of the projecting portion below the projecting portion is reduced from the base layer toward the projecting portion. A first conductive layer having a base layer and a protrusion protruding from an upper surface of the base layer; an insulating layer positioned on the first conductive layer so as to cover the base layer and the protrusion; and the insulation A wiring board comprising: a second conductive layer positioned on the layer; and a via conductor formed in the insulating layer and connecting the protruding portion of the first conductive layer and the second conductive layer;
An electronic component mounted on the wiring board and electrically connected to the first conductive layer and the second conductive layer;
The projecting portion of the first conductive layer has a projecting portion that projects from the upper side surface in a direction along the upper surface of the base layer and is spaced from the upper surface of the base layer via the insulating layer,
A mounting structure having a concave corner between the via conductor and the overhanging portion and between the overhanging portion and the protruding portion below the overhanging portion. Preparing a first conductive layer having an underlayer and a protruding portion protruding from the upper surface of the underlayer; and forming an insulating layer on the first conductive layer so as to cover the underlayer and the protruding portion And a process of
Forming a via hole in the insulating layer, exposing a part of the protrusion in the via hole;
Forming a via conductor connected to the protrusion in the via hole;
Forming a second conductive layer connected to the via conductor on the insulating layer,
The step of preparing the first conductive layer includes:
Preparing the underlayer, forming a resist layer on the underlayer, forming the protrusion on the underlayer exposed between the resist layers, and removing the resist layer Have
In the step of forming the protrusion,
The method of manufacturing a wiring board, wherein the protrusion is formed so that a part of the protrusion is formed on an upper surface of the resist layer.

Images