JP2014049701A - Wiring board and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve adhesion between a through conductor and a wiring conductor layer, and to provide a wiring board with excellent connection reliability.SOLUTION: A wiring conductor layer 23 and a through hole 26 continuously penetrating resin insulating layers 21 and 22 are formed on a wiring board 10 for electronic component inspection. A via conductor 27 connected to the wiring conductor layer 23 is formed by filling the through hole 26 with a conductive paste. A through hole 26 portion penetrating the wiring conductor layer 23 includes a small diameter hole 51 located on surface sides of the resin insulating layers 21 and 22 and formed by an inner wall surface of the wiring conductor layer 23 and a large diameter part 52 provided in a position more away from surfaces of the resin insulating layers 21 and 22 than the small diameter part 51 and formed so that a diameter of the inner wall surface of the wiring conductor layer 23 is enlarged to the small diameter part 51.

Description

  The present invention is formed by filling a resin insulating layer, a wiring conductor layer formed on the surface of the resin insulating layer, a through hole penetrating the wiring conductor layer and the resin insulating layer, and filling the through hole with a conductive paste. In addition, the present invention relates to a wiring board including a through conductor connected to a wiring conductor layer and a method for manufacturing the wiring board.

  In recent years, semiconductor integrated circuit elements (IC chips) used as computer microprocessors and the like have become increasingly faster and more functional, with an accompanying increase in the number of terminals and a tendency to narrow the pitch between terminals. . In general, a large number of terminals are densely arranged in an array on the bottom surface of an IC chip. In order to inspect electronic components such as the IC chip, a wiring board for inspecting electronic components is used.

  As a wiring board for inspecting electronic components, a resin insulation portion formed by laminating a plurality of resin insulation layers and a plurality of conductor layers on the upper layer side of a ceramic substrate portion obtained by laminating a plurality of ceramic insulation layers and a plurality of conductor layers. The formed wiring board has been put into practical use. In this electronic component inspection wiring board, each ceramic insulating layer and each resin insulating layer are provided with through conductors (via conductors) penetrating the insulating layers, and electrical connection between the layers is achieved by the through conductors. .

  FIG. 14 shows an example of connection between the through conductor 102 formed so as to penetrate the resin insulating layer 101 in the thickness direction and the wiring conductor layer 103 formed on the surface of the resin insulating layer 101 in the wiring substrate 100. Yes. In the wiring substrate 100 of FIG. 14, a through hole 104 penetrating the resin insulating layer 101 and the wiring conductor layer 103 is formed, and the through conductor 102 is formed in the through hole 104 (see, for example, Patent Document 1). Such a wiring board 100 is manufactured by the following method. Specifically, first, a resin film with a copper foil in which a copper foil is attached to the surface of the resin insulating layer 101 is prepared. Next, the wiring conductor layer 103 is formed by patterning the copper foil of the resin film by, for example, a subtractive method. Thereafter, a through hole 104 penetrating the resin insulating layer 101 and the wiring conductor layer 103 is formed by laser drilling or the like, and a through conductor 102 connected to the wiring conductor layer 103 is formed by filling the through hole 104 with a conductive paste. To do.

JP2003-318546A (FIG. 11) JP 2003-92471 A

  By the way, in the wiring board 100, the through conductor 102 and the wiring conductor layer 103 are connected via the side surface of the end portion of the through conductor 102, but the through hole 104 in which the through conductor 102 is formed is a straight having the same diameter. It is a through hole with a simple wall surface. Accordingly, the area of the side surface of the through conductor 102 connected to the wiring conductor layer 103 is small, and the adhesion strength is weakened. In particular, in a wiring board in which the fine pitch of the wiring conductor layer 103 is achieved, the wiring conductor layer 103 is formed thin, and the size of the through conductor 102 tends to be small. In such a case, the adhesion strength between the through conductor 102 and the wiring conductor layer 103 is weakened. Further, since the wiring conductor layer 103 is formed by patterning of copper foil and the through conductor 102 is formed of a conductive paste, the shrinkage ratio between the through conductor 102 (conductive paste) and the wiring conductor layer 103 (copper foil). Is different. Due to the difference in shrinkage rate, a gap 106 is formed at the interface between the through conductor 102 and the wiring conductor layer 103 (see FIG. 15). For this reason, connection reliability is poor near the interface between the through conductor 102 and the wiring conductor layer 103, and an open defect (disconnection) is likely to occur.

  Further, in order to improve the connectivity between the through conductor 102 and the wiring conductor layer 103, as shown in FIG. 16, the conductive paste is embedded so as to protrude around the opening of the through hole 104 in the wiring conductor layer 103. A wiring board 110 on which a conductor 102 is formed is known (see, for example, Patent Document 2). However, when a plurality of resin insulation layers 101 are formed in a multilayer, the conductive paste protruding on the wiring conductor layer 103 is crushed and spread by the pressure applied during lamination. In this case, the conductive paste spreads to the wiring pattern of the adjacent wiring conductor layer 103, which may cause a short circuit between the wiring patterns. For this reason, it is necessary to widen the interval between the wiring patterns or widen the width of the wiring pattern, and it becomes difficult to miniaturize and increase the density of the wiring. Furthermore, the conductive paste protruding on the wiring conductor layer 103 is crushed and spread by the pressurization at the time of lamination, which causes a problem that the surface of the wiring conductor layer 103 is uneven.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a wiring board that improves the adhesion between the through conductor and the wiring conductor layer and is excellent in connection reliability. Another object is to provide a method of manufacturing a wiring board capable of manufacturing the wiring board.

  And as means (means 1) for solving the above-mentioned problems, a resin insulating layer, a wiring conductor layer formed on the surface of the resin insulating layer, the wiring conductor layer and the resin insulating layer are continuously provided. A wiring board comprising a through hole that penetrates and a through conductor that is formed by filling a conductive paste in the through hole and is connected to the wiring conductor layer, wherein the through hole includes the wiring conductor layer. In the penetrating part, a small-diameter portion that is located on the surface side of the resin insulating layer and formed by the inner wall surface of the wiring conductor layer, and the small-diameter portion that is provided at a position farther from the surface of the resin insulating layer than the small-diameter portion A large-diameter portion formed so that the diameter of the inner wall surface of the wiring conductor layer is enlarged with respect to the portion, and the through-conductor fills the through-hole including the small-diameter portion and the large-diameter portion. A wiring board characterized by being formed That.

  According to the invention described in Means 1, the through hole includes a small diameter portion and a large diameter portion formed so that the diameter of the inner wall surface of the wiring conductor layer is larger than the small diameter portion in the portion penetrating the wiring conductor layer. In addition, a through conductor is filled in the through hole. If it does in this way, the contact area of a penetration conductor and a wiring conductor layer increases, and the adhesiveness of these penetration conductors and a wiring conductor layer can be improved. Therefore, the connection reliability in the vicinity of the interface between the wiring conductor layer and the through conductor can be increased, and the open defect as in the conventional technique is less likely to occur.

  A stepped surface extending from the inner wall surface of the small diameter portion toward the inner wall surface of the large diameter portion may be formed at a boundary portion between the large diameter portion and the small diameter portion of the wiring conductor layer. If it does in this way, the adhesiveness of a penetration conductor and a wiring conductor layer can be improved, and the connection reliability of a wiring conductor layer and a penetration conductor can be improved. The large diameter portion may be formed so as to gradually increase in diameter as it goes to the opening side, that is, to have a tapered inner wall surface. Even if it does in this way, the contact area of a penetration conductor and a wiring conductor layer increases, and the adhesiveness of these penetration conductors and a wiring conductor layer can be improved.

  A flat surface parallel to the surface of the wiring conductor layer may exist on the step surface. In this case, even when the through conductor contracts and a gap is generated in the wall surface of the through hole, the wiring conductor layer and the through conductor can be reliably adhered to each other on the flat surface of the boundary portion, as in the prior art. Open defects are less likely to occur.

  The wiring board is provided on a lower layer side of the resin insulation part, in which a plurality of resin insulation layers and a plurality of wiring conductor layers are laminated, and a plurality of ceramic insulation layers and a plurality of conductor layers are laminated. A multilayer wiring board provided with a ceramic substrate part may be used. The multilayer wiring board may be used as an electronic component inspection wiring board. In this case, since the wiring conductor layers of the respective layers are reliably connected through the through conductors, a multilayer wiring board having excellent connection reliability can be obtained. Furthermore, since the connection reliability between the wiring conductor layer and the through conductor in the wiring board for inspecting electronic components can be ensured, it is possible to reliably inspect electronic components in which a large number of terminals are densely arranged.

  The through conductor may be formed so that the position of the end face of the through conductor is inside the opening of the large diameter portion in the through hole. If it does in this way, since a penetration conductor does not protrude and spread from a penetration hole by pressurization at the time of lamination, miniaturization and densification of wiring in a wiring board can be attained.

  When the thickness of the large diameter portion is 50% or more of the thickness of the wiring conductor layer, the through conductor can be reliably filled and formed in the large diameter portion. In addition, the diameter of the large diameter portion may be 1.1 times or more the diameter of the small diameter portion. When the diameter of the large diameter portion is increased in this way, sufficient adhesion between the through conductor and the wiring conductor layer can be ensured.

  The diameter of the through conductor may be 50 μm or less, and the thickness of the metal foil may be 10 μm or less. Thus, if the diameter of the through conductor is reduced and the metal foil (wiring conductor layer) is thinned, the wiring on the wiring board can be miniaturized and densified.

  Wiring conductor layers are provided on both the upper and lower surfaces of the resin insulating layer, and the through conductor is a conductor that penetrates the upper wiring conductor layer, the lower wiring conductor layer, and the resin insulating layer. A portion that penetrates the wiring conductor layer and the wiring conductor layer on the lower surface side may be provided with a large diameter portion and a small diameter portion. Even if it does in this way, the contact area of a penetration conductor and a wiring conductor layer increases, and the adhesiveness of these penetration conductors and a wiring conductor layer can be improved.

  The resin insulating layer may include a first resin layer made of a polyimide-based thermosetting resin and a second resin layer formed on both surfaces of the first resin layer and made of a polyimide-based thermoplastic resin. . In this case, since the second resin layer functions as an adhesive layer by applying pressure and heating, a multilayer wiring board in which a plurality of resin insulating layers are integrated can be reliably manufactured.

  The resin insulating layer may be formed using a resin other than a polyimide-based resin, and can be appropriately selected in consideration of insulation, heat resistance, moisture resistance, and the like. In addition, the resin insulation layer is formed on a composite material of resin and glass fiber (glass woven fabric or glass nonwoven fabric) or organic fiber such as polyamide fiber, or a three-dimensional network fluorine resin base material such as continuous porous PTFE. A resin-resin composite material impregnated with a curable resin may be used.

  Further, as another means (means 2) for solving the above-mentioned problem, there is provided a method for manufacturing a wiring board according to means 1, wherein the wiring is provided on one or both sides of a resin insulating material to be the resin insulating layer. A preparation step of preparing a resin film on which a metal layer to be a conductor layer is formed, a first portion that is a non-through hole that does not penetrate the metal layer of the resin film and is the large-diameter portion, the metal layer, and A through-hole forming step for forming a through-hole penetrating the resin insulating material and forming the second portion serving as the small-diameter portion; and filling the first portion and the second portion with a conductive paste There is a method for manufacturing a wiring board, comprising: a through conductor forming step for forming the through conductor; and a conductive layer forming step for patterning the wiring conductor layer by etching the metal layer.

  According to the invention described in Means 2, in the through hole forming step, a first portion that does not penetrate the metal layer of the resin film (a non-through hole that becomes a large diameter portion) is formed, and penetrates the metal layer and the resin insulating material. A second portion (a through hole that becomes a small diameter portion) is formed. Thereafter, in the through conductor forming step, the first portion and the second portion are filled with the conductive paste to form the through conductor. In the conductor layer forming step, the wiring conductor layer connected to the through conductor is patterned by etching the metal layer. Thus, since the large diameter portion is provided in the through hole forming the through conductor, the contact area between the through conductor and the wiring conductor layer is increased. Therefore, the adhesion between the through conductor and the wiring conductor layer can be improved, and a wiring board with high connection reliability can be manufactured.

  In the through hole forming step, after forming the non-through hole by laser processing, a through hole that opens at the center of the bottom surface may be formed so that the center coincides with the non-through hole. In this case, the small diameter portion and the large diameter portion in the through hole can be reliably formed with high positional accuracy. Further, in the through hole forming step, after forming the through hole, a non-through hole may be formed around the through hole. Even if it does in this way, the through-hole which has a small diameter part and a large diameter part can be formed.

  In the preparation step, a resin film with a metal foil in which a metal foil as a metal layer is attached on the surface of the resin insulating material may be prepared. Moreover, in a preparatory process, you may prepare the resin film which formed the plating layer and sputter | spatter layer as a metal layer on the surface of the resin insulating material.

  The metal foil of the resin film may be a copper foil, and the conductive paste used in the through conductor forming process may be a silver paste. In this case, since a resin film with a copper foil and a silver paste, which are general-purpose materials that are generally used, can be used, the manufacturing cost of the wiring board can be kept low.

  Further, the conductor layer forming step may be performed after the through hole forming step and the through conductor forming step, or the conductor layer forming step may be performed before the through conductor forming step. However, if the through conductor forming process is performed after the conductor layer forming process, the conductive paste may adhere to the end of the wiring conductor layer in the through conductor forming process. In that case, the conductive paste may be wiped off, etc. An extra step is required. On the other hand, when the conductor layer forming step is performed after the through conductor forming step, a work step such as wiping off the conductive paste is not required, and the wiring board can be manufactured relatively easily.

  In the case of manufacturing a multilayer wiring board, it may further include a laminating step of laminating a plurality of resin insulating layers patterned with wiring conductor layers in the thickness direction. In this case, since the through conductor does not protrude from the through hole due to the pressurization during the lamination process, the wiring in the multilayer wiring board can be miniaturized.

Sectional drawing which shows schematic structure of the wiring board for electronic component inspection in this Embodiment. The expanded sectional view which shows the connection part of a wiring conductor layer and a via conductor. Explanatory drawing which shows the through-hole formation process of a ceramic substrate part. Explanatory drawing which shows the formation process of the via conductor of a ceramic substrate part, and a conductor layer. Explanatory drawing which shows the lamination process of a ceramic substrate part. Explanatory drawing which shows the preparation process of a resin film. Explanatory drawing which shows a through-hole formation process. Explanatory drawing which shows a through-hole formation process. Explanatory drawing which shows a penetration conductor formation process. Explanatory drawing which shows a conductor layer formation process. Explanatory drawing which shows a lamination process. Sectional drawing which shows the through hole and via conductor of another embodiment. Sectional drawing which shows the through hole and via conductor of another embodiment. Explanatory drawing which shows the conventional wiring board. Explanatory drawing which shows the conventional wiring board. Explanatory drawing which shows the conventional wiring board.

  Hereinafter, an embodiment in which the present invention is embodied in an electronic component inspection wiring board will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a schematic configuration of an electronic component inspection wiring board according to the present embodiment.

  An electronic component inspection wiring board 10 shown in FIG. 1 is a component used in a part of an inspection apparatus for performing an electrical inspection of an IC chip. The electronic component inspection wiring board 10 includes a resin insulating portion 20 and a ceramic substrate portion 30 provided on the lower layer side of the resin insulating portion 20. The electronic component inspection wiring substrate 10 is a substrate having a length and width of about 10 cm and a thickness of about 4 mm, and the main surface 11 (the surface of the resin insulating portion 20) of the wiring substrate 10 is an inspection target in use. Arranged toward the electronic component.

  A plurality of ceramic insulating layers 31, 32, 33 and a plurality of conductor layers 34 are laminated on the ceramic substrate portion 30. The ceramic insulating layers 31 to 33 are, for example, alumina sintered bodies, and the conductor layer 34 is a metallized layer such as tungsten or molybdenum. In the ceramic substrate portion 30, each ceramic insulating layer 31 to 33 is formed with a through hole 36 penetrating in the thickness direction, and a via conductor 37 connected to the interlayer conductor layer 34 is formed in the through hole 36. Is formed. Each through-hole 36 has a circular cross section, and the inner diameter thereof is about 60 μm. Each via conductor 37 also has a circular cross section, and the outer diameter thereof is about 60 μm. The via conductor 37 is made of a metallized layer such as tungsten or molybdenum in the same manner as the conductor layer 34. Further, on the back surface 12 of the wiring substrate 10 (the surface of the ceramic substrate portion 30), a plurality of back surface side terminals 38 are formed in an array over almost the entire area. Each back terminal 38 has a circular cross section, and the diameter of the back terminal 38 is set to about 1.0 mm.

  A plurality of resin insulation layers 21 and 22 and a plurality of wiring conductor layers 23 are laminated on the resin insulation portion 20. The resin insulating layers 21 and 22 are insulating layers made of, for example, a polyimide resin. Specifically, the resin insulating layers 21 and 22 are formed on both surfaces of the first resin layer 24 made of a polyimide-based thermosetting resin and the first resin layer 24, and are made of a second resin made of a polyimide-based thermoplastic resin. And a resin layer 25. In the present embodiment, the thickness of the first resin layer 24 constituting the resin insulating layers 21 and 22 is about 20 μm, and the thickness of the second resin layer 25 is about 5 μm. That is, the resin insulating layers 21 and 22 are about 30 μm. The wiring conductor layer 23 is a conductor layer made of, for example, copper and has a thickness of about 5 μm. In the resin insulating portion 20, a through hole 26 penetrating the resin insulating layers 21 and 22 and the wiring conductor layer 23 is formed, and a via conductor 27 (connected to the interlayer wiring conductor layer 23 in the through hole 26 ( (Through conductor) is formed. The through hole 26 and the via conductor 27 of the resin insulating portion 20 also have a circular cross section.

  In addition, a plurality of main surface side terminals 28 (component connection terminals) constituting the wiring conductor layer 23 are formed in an array at a central portion on the main surface 11 (surface of the resin insulating portion 20) of the wiring board 10. ing. The main surface side terminal 28 has a circular cross section, and its diameter is set to about 50 μm, for example.

  As shown in FIG. 1 and FIG. 2, the through hole 26 is formed on the inner layer side (resin insulating layer 21) of the wiring conductor layer 23 in a portion that penetrates the wiring conductor layer 23 (main surface side terminal 28 or inner layer wiring pattern). , 22) and a small-diameter portion 51 formed by the inner wall surface of the wiring conductor layer 23, and a surface layer side of the wiring conductor layer 23 (the surface of the resin insulating layers 21, 22 away from the small-diameter portion 51). And a large diameter portion 52 provided at a position). The small diameter portion 51 has a diameter D1 equal to the through hole 26 in the resin insulating layers 21 and 22, and the diameter D1 is about 35 μm. The large-diameter portion 52 is formed so that the diameter of the inner wall surface of the wiring conductor layer 23 is larger than the small-diameter portion 51, and the diameter D2 is about 40 μm. The via conductor 27 is filled in the through hole 26 including the small diameter portion 51 and the large diameter portion 52. Therefore, the via conductor 27 has a diameter of about 35 μm at the small diameter portion 51 and a diameter of about 40 μm at the large diameter portion 52. The large diameter portion 52 has a thickness of about 3 μm, which is 50% or more of the thickness of the wiring conductor layer 23.

  In the present embodiment, a step surface 53 extending from the inner wall surface of the small diameter portion 51 toward the inner wall surface of the large diameter portion 52 is formed at the boundary portion between the small diameter portion 51 and the large diameter portion 52 in the through hole 26. Further, the step surface 53 has a flat surface 54 parallel to the surface of the wiring conductor layer 23 at the boundary between the small diameter portion 51 and the large diameter portion 52. In addition to the inner wall surfaces of the small diameter portion 51 and the large diameter portion 52, the via conductor 27 is formed in close contact with the step surface 53.

  As shown in FIG. 1, in the electronic component inspection wiring substrate 10, each main surface side terminal 28 is connected to an inner layer side wiring conductor layer 23 via a via conductor 27, and further, a conductor layer of the ceramic substrate portion 30. 34 and via conductors 37 are connected to the back-side terminals 38.

  Next, a method for manufacturing the electronic component inspection wiring board 10 in the present embodiment will be described.

  First, a plurality of green sheets are formed using a ceramic material mainly composed of alumina powder. Then, a plurality of through holes 36 are formed at predetermined positions by drilling the plurality of green sheets 41 by laser irradiation processing, punching processing, drill processing, or the like (see FIG. 3). Thereafter, a conductive paste (for example, tungsten or molybdenum paste) is filled in the through holes 36 of each green sheet 41 by using a conventionally known paste press-fitting and filling device (not shown) to form an unfired via conductor 37. Further, a conductive paste is printed using a conventionally known paste printing apparatus to form the unfired conductor layer 34 and the back-side terminal 38 (see FIG. 4). The order of press-fitting and printing with the conductive paste may be reversed.

  Then, after the conductive paste is dried, the plurality of green sheets 41 are stacked and disposed, and a pressing force is applied in the sheet stacking direction, whereby the green sheets 41 are bonded and integrated to form a ceramic laminate 43. (See FIG. 5). Next, the ceramic laminate 43 is degreased and fired at a predetermined temperature for a predetermined time. As a result, the alumina of the green sheet 41 and the copper in the paste are simultaneously sintered, and the ceramic substrate portion 30 is formed.

  Moreover, the resin insulation part 20 is produced with the following method. Specifically, as shown in FIG. 6, copper having a copper foil 47 to be the wiring conductor layer 23 formed on one surface 46 (upper surface in FIG. 6) of the resin insulating material 45 to be the resin insulating layers 21 and 22. A resin film 48 with foil is prepared (preparation step). The resin insulating material 45 includes a first resin layer 24 made of a polyimide-based thermosetting resin, and a second resin layer 25 made of a polyimide-based thermoplastic resin disposed on both surfaces of the first resin layer 24. Composed. A copper foil 47 having a thickness of 5 μm is attached to the upper surface 46 side of the resin insulating material 45.

  Next, as shown in FIG. 7, a first portion that is a non-through hole that does not penetrate the copper foil 47 of the resin film 48 and becomes the large-diameter portion 52 is formed by laser processing (see FIG. 7). The non-through hole of the first portion 52 has a diameter of about 40 μm and a depth of about 3 μm. Then, the 2nd part which is a through-hole which penetrates the copper foil 47 and the resin insulating material 45, and becomes the small diameter part 51 is formed by laser processing (refer FIG. 8). Here, the second portion 51 (through hole) that opens at the center of the bottom surface is formed so that the center coincides with the first portion 52 (non-through hole). The diameter of the through hole of the second portion 51 is about 35 μm. In this way, the resin insulating material 45 and the copper foil 47 of the resin film 48 are continuously penetrated, and the through hole 26 having the small diameter portion 51 and the large diameter portion 52 is formed in the through portion of the copper foil 47 (through hole formation). Process).

  Next, using a paste press-fitting and filling device (not shown), as shown in FIG. 9, a silver paste as a conductive paste is filled into the through hole 26 of the resin film 48 to form a via conductor 27 (through). Conductor formation process). Here, the via conductor 27 is formed so that the position of the end face of the via conductor 27 is inside the opening of the large diameter portion 52 in the through hole 26.

  Thereafter, the copper foil 47 of the resin film 48 is patterned by a subtractive method to form the wiring conductor layer 23 (main surface side terminal 28) on the resin insulating layer 21 (see FIG. 10). Specifically, a dry film is laminated on the upper surface 46 and the lower surface 49 of the resin insulating material 45, and the dry film is exposed and developed. Thus, an etching resist is formed on the lower surface 49 of the resin insulating layer 21 so as to cover the entire surface, and an etching resist having a predetermined pattern is formed on the upper surface 46 of the resin insulating layer 21. In this state, each main surface side terminal 28 is formed on the resin insulating layer 21 by performing patterning by etching on the copper foil 47 of the resin film 48 (conductor layer forming step). Thereafter, by contacting with the stripping solution, the etching resist remaining on each main surface side terminal 28 is removed, and the etching resist on the back surface 49 side is removed.

  Through such a process, the resin insulating layer 21 having each main surface side terminal 28 and the via conductor 27 connected to each terminal 28 is formed. Moreover, the resin insulating layer 22 which has the wiring pattern of the wiring conductor layer 23 and the via conductor 27 connected to the wiring pattern is formed by performing the preparation process-conductor layer formation process mentioned above similarly.

Next, the resin insulating layer 21 and the resin insulating layer 22 are laminated and pressed with a pressure of about 20 kgf / cm ² while heating to a temperature of about 180 ° C. As a result, as shown in FIG. 11, the resin insulation layers 21 and 22 are pressure-bonded to form the resin insulation part 20 (lamination process). And the resin insulation part 20 is laminated | stacked and arrange | positioned on the upper layer side of the ceramic substrate part 30, and it pressurizes with the pressure of about 75 kgf / cm < ² >, heating to the temperature of about 350 degreeC. As a result, as shown in FIG. 1, the electronic component inspection wiring substrate 10 in which the resin insulating portion 20 and the ceramic substrate portion 30 are integrated is manufactured. In the above manufacturing process, the electronic component inspection wiring substrate 10 may be manufactured by laminating the resin insulating layer 21 and the resin insulating layer 22 simultaneously with the ceramic substrate portion 30.

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

  (1) In the electronic component inspection wiring board 10 of the present embodiment, the through hole 26 in which the via conductor 27 is formed has a smaller diameter portion 51 and a wiring than the small diameter portion 51 at a portion that penetrates the wiring conductor layer 23. And a large-diameter portion 52 formed so that the diameter of the inner wall surface of the conductor layer 23 is increased. In this way, the contact area between the via conductor 27 and the wiring conductor layer 23 is increased as compared with the through hole 104 (see FIG. 4) having a straight wall with the same diameter as in the prior art. And the wiring conductor layer 23 can be improved in adhesion. Therefore, the connection reliability in the vicinity of the interface between the wiring conductor layer 23 and the via conductor 27 can be increased, and the open defect as in the prior art is less likely to occur.

  (2) In the electronic component inspection wiring board 10 of the present embodiment, the boundary between the small diameter portion 51 and the large diameter portion 52 in the through hole 26 is located from the inner wall surface of the small diameter portion 51 to the inner wall surface of the large diameter portion 52. A step surface 53 extending toward the surface is formed, and a flat surface 54 parallel to the surface of the wiring conductor layer 23 exists on the step surface 53. In this case, even when the via conductor 27 contracts and a gap is generated in the wall surface of the through hole 26, the wiring conductor layer 23 and the via conductor 27 can be reliably adhered to each other on the flat surface 54 at the boundary portion. Open defects like technology are less likely to occur.

  (3) In the electronic component inspection wiring board 10 of the present embodiment, the via conductor 27 is formed so that the position of the end face of the via conductor 27 is inside the opening of the large diameter portion 52 in the through hole 26. . In this case, the via conductor 27 does not protrude from the through hole 26 due to the pressurization at the time of lamination, so that the wiring in the electronic component inspection wiring board 10 can be miniaturized and densified. Further, since the end portion of the via conductor 27 does not protrude from the opening of the large-diameter portion 52 in the through hole 26, the surface of the wiring conductor layer 23 is not uneven after the resin insulating layers 21 and 22 are laminated.

  (4) In the case of the present embodiment, in the through hole forming step, a non-through hole (a first portion that becomes the large diameter portion 52) that does not penetrate the copper foil 47 of the resin film 48 is formed by laser processing. Thereafter, a through hole (second portion that becomes the small diameter portion 51) that is opened at the center of the bottom surface is formed by laser processing so that the center coincides with the non-through hole. If it does in this way, the small diameter part 51 and the large diameter part 52 in the through-hole 26 can be reliably formed with a sufficient positional accuracy.

  (5) In the case of this embodiment, since the resin film 48 with copper foil and silver paste, which are general-purpose materials that are generally used, are used, the manufacturing cost of the electronic component inspection wiring board 10 is kept low. Can do.

  (6) In the case of the present embodiment, the conductor layer forming step is performed after the through conductor forming step. On the contrary, if the through conductor forming process is performed after the conductor layer forming process, the conductive paste may adhere to the end of the wiring conductor layer, etc. In such a case, an excess of the conductive paste is wiped off. A process is required. On the other hand, when the conductor layer forming step is performed after the through conductor forming step as in the present embodiment, a work step such as wiping off the conductive paste is not required, and the wiring board 10 is manufactured relatively easily. be able to.

  (7) In the electronic component inspection wiring board 10 of the present embodiment, the diameter D2 of the inner wall surface of the large diameter portion 52 is about 40 μm, and 1.1 of the diameter D1 (about 35 μm) of the inner wall surface of the small diameter portion 51. It is more than double. Further, the depth of the large diameter portion 52 is 3 μm, which is ½ or more of the thickness of the wiring conductor layer 23. When the large diameter portion 52 is formed in this way, the via conductor 27 can be reliably filled and formed in the large diameter portion 52, and sufficient adhesion between the via conductor 27 and the wiring conductor layer 23 can be ensured.

  (8) In the electronic component inspection wiring substrate 10 of the present embodiment, the resin insulating layers 21 and 22 are formed on both surfaces of the first resin layer 24 made of a polyimide-based thermosetting resin and the first resin layer 24. The second resin layer 25 is made of a polyimide-based thermoplastic resin. In this case, since the second resin layer 25 functions as an adhesive layer by applying pressure and heating in the laminating process of the resin insulating layers 21 and 22, a wiring board in which a plurality of resin insulating layers 21 and 22 are integrated. 10 can be manufactured reliably.

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

  In the electronic component inspection wiring substrate 10 of the above embodiment, the through hole 26 forming the via conductor 27 has the flat surface 54 formed at the boundary portion between the small diameter portion 51 and the large diameter portion 52. It is not limited. For example, like the through hole 26 shown in FIG. 12, the large-diameter portion 52 may be formed so as to gradually increase in diameter toward the opening side, that is, to have a tapered inner wall surface. The through hole 26 of FIG. 12 is also formed so that the diameter D1 of the small diameter portion 51 is about 35 μm and the diameter D2 of the large diameter portion 52 is about 40 μm. Here, the diameter D1 of the small diameter portion 51 is a value measured at a position farthest from the surface of the resin insulating layer 21 in the small diameter portion 51. Further, the diameter D2 of the large diameter portion 52 is a value measured at a position closest to the surface of the resin insulating layer 21 in the large diameter portion 52. Even if the through hole 26 is formed in this way, the contact area between the via conductor 27 and the wiring conductor layer 23 increases, and the adhesion between the via conductor 27 and the wiring conductor layer 23 can be improved.

  The method for forming the through hole 26 is not limited to laser processing as in the above embodiment, and other methods such as etching and punching may be used. Specifically, for example, after forming the first portion (non-through hole) that becomes the large diameter portion 52 by etching the copper foil 47, the second portion (through hole) that becomes the small diameter portion 51 is formed by laser processing. It may be formed. Furthermore, after forming the 1st part (non-through-hole) used as the large diameter part 52 in the surface of the copper foil 47 by giving a concave process (for example, engraving process) using a press etc., the small diameter part 51 and The second part (through hole) to be formed may be formed by laser processing. When the through hole 26 is formed by this method, as shown in FIG. 13, the wiring conductor layer 23 has a shape in which the inner layer side around the through hole 26 protrudes toward the resin insulating layer 21 side by denting the surface layer side. Become. Even if the via conductor 27 is filled and formed in the through hole 26 formed in this way, the contact area between the via conductor 27 and the wiring conductor layer 23 is increased, and the adhesion between the via conductor 27 and the wiring conductor layer 23 is improved. be able to.

  In the above embodiment, the electronic component inspection wiring substrate 10 including the resin insulating portion 20 and the ceramic substrate portion 30 is embodied. However, the present invention may be embodied in a wiring substrate used for other applications. . For example, the present invention may be embodied in a multilayer wiring board composed of a plurality of resin insulation layers, or may be embodied in a wiring board composed of a single resin insulation layer. In the case of manufacturing a wiring board made of a single resin insulating layer, a copper foil in which a copper foil 47 to be the wiring conductor layer 23 is formed on both the upper surface 46 and the lower surface 49 of the resin insulating material 45 in the preparation step. The attached resin film 48 is prepared. Then, similarly to the above embodiment, a through hole forming step is performed, and a first portion (a non-through hole that becomes the large diameter portion 52) and a second portion are formed on the copper foil 47 on both surfaces 46 and 49 of the resin insulating material 45. A through hole 26 having a portion (a through hole that becomes the small diameter portion 51) is formed. Thereafter, the via conductor 27 is formed by filling the through hole 26 with a conductive paste. In this way, the small diameter portion 51 and the large diameter portion 52 are provided in a portion that penetrates the wiring conductor layer 23 on the upper surface side and the wiring conductor layer 23 on the lower surface side of the through hole 26. As a result, the contact area between the via conductor 27 and the wiring conductor layer 23 increases, and the adhesion between the via conductor 27 and the wiring conductor layer 23 can be improved.

  -In the said embodiment, although silver paste was used as an electrically conductive paste, it is not limited to this, You may use other electrically conductive pastes, such as a copper paste.

  Next, in addition to the technical ideas described in the claims, the technical ideas grasped by the embodiments described above are listed below.

  (1) In the wiring board according to the first aspect, the large diameter portion is formed so as to gradually increase in diameter toward the opening side.

  (2) The wiring board characterized in that in the means 1, the through conductor is formed so that the position of the end face of the through conductor is located inside the opening of the large diameter portion in the through hole.

  (3) In the means 1, the wiring board is characterized in that the thickness of the large diameter portion is 50% or more of the thickness of the wiring conductor layer.

  (4) The wiring board according to (1), wherein the diameter of the inner wall surface of the large diameter portion is 1.1 times or more than the diameter of the inner wall surface of the small diameter portion.

  (5) The wiring board according to means 1, wherein the through conductor has a diameter of 50 μm or less.

  (6) The wiring board according to means 1, wherein the thickness of the metal foil is 10 μm or less.

  (7) In means 1, the resin insulation layer is formed on both surfaces of the first resin layer made of a polyimide-based thermosetting resin and the polyimide-based thermoplastic resin. A wiring board comprising a layer.

  (8) In the means 1, the wiring board is an electronic component inspection wiring board for inspecting an electronic component.

  (9) In the means 1, the wiring conductor layer is provided on both the upper surface and the lower surface of the resin insulating layer, and the penetrating conductor includes the wiring conductor layer on the upper surface, the wiring conductor layer on the lower surface, and the resin insulating layer. The large diameter portion and the small diameter portion are provided in a portion penetrating the wiring conductor layer on the upper surface side and the wiring conductor layer on the lower surface side of the through hole. Wiring board.

  (10) The method of manufacturing a wiring board according to (2), wherein, in the through hole forming step, after the through hole is formed, the non-through hole is formed around the through hole.

  (11) The method of manufacturing a wiring board according to the method 2, wherein the conductor layer forming step is performed after the through hole forming step and the through conductor forming step.

  (12) The method for manufacturing a wiring board according to (2), further comprising a laminating step of laminating a plurality of the resin insulating layers formed by patterning the wiring conductor layers in the thickness direction.

DESCRIPTION OF SYMBOLS 10 ... Wiring board for electronic component inspection as a wiring board 21, 22 ... Resin insulating layer 23 ... Wiring conductor layer 26 ... Through hole 27 ... Via conductor as penetrating conductor 28 ... Main surface side terminal constituting wiring conductor layer 45 ... Resin insulating material 46 ... Upper surface as one surface of resin insulating material 47 ... Copper foil as metal layer 48 ... Resin film 49 ... Lower surface as one surface of resin insulating material 51 ... Small diameter portion 52 ... Large diameter portion

Claims (8)

A resin insulating layer; a wiring conductor layer formed on a surface of the resin insulating layer; a through hole that continuously passes through the wiring conductor layer and the resin insulating layer; and a conductive paste is filled in the through hole. A wiring board comprising a through conductor formed and connected to the wiring conductor layer,
The through hole has a small diameter portion formed by an inner wall surface of the wiring conductor layer located on the surface side of the resin insulating layer in a portion penetrating the wiring conductor layer, and the resin insulating layer more than the small diameter portion. A large-diameter portion formed so that the diameter of the inner wall surface of the wiring conductor layer is increased with respect to the small-diameter portion provided at a position away from the surface;
The wiring board according to claim 1, wherein the through conductor is filled in the through hole including the small diameter portion and the large diameter portion.   A stepped surface extending from an inner wall surface of the small diameter portion toward an inner wall surface of the large diameter portion is formed at a boundary portion between the large diameter portion and the small diameter portion of the wiring conductor layer. The wiring board according to claim 1.   The wiring board according to claim 2, wherein the stepped surface has a flat surface parallel to the surface of the wiring conductor layer.   A resin insulation part in which a plurality of resin insulation layers and a plurality of wiring conductor layers are laminated, and a ceramic in which a plurality of ceramic insulation layers and a plurality of conductor layers are laminated on a lower layer side of the resin insulation part The wiring board according to claim 1, further comprising a board portion. A method of manufacturing a wiring board according to any one of claims 1 to 4,
A preparation step of preparing a resin film in which a metal layer to be the wiring conductor layer is formed on one side or both sides of the resin insulating material to be the resin insulating layer;
A first portion that is a non-through hole that does not penetrate the metal layer of the resin film and serves as the large diameter portion, and a second portion that is a through hole that penetrates the metal layer and the resin insulating material and serves as the small diameter portion. A through hole forming step for forming a portion of
A through conductor forming step of filling the first portion and the second portion with a conductive paste to form the through conductor; and
And a conductor layer forming step of patterning the wiring conductor layer by etching the metal layer.   The said through-hole formation process forms the said through-hole opened in the center of the bottom face so that a center may correspond with the said non-through-hole after forming the said non-through-hole by laser processing. 5. A method for manufacturing a wiring board according to 5.   The method for manufacturing a wiring board according to claim 5 or 6, wherein in the preparation step, a resin film with a metal foil is prepared by attaching a metal foil as the metal layer on the surface of the resin insulating material. .   The method for manufacturing a wiring board according to claim 7, wherein the metal foil is a copper foil, and the conductive paste used in the through conductor forming step is a silver paste.

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