JP4434856B2 - WIRING BOARD MANUFACTURING METHOD AND CONNECTED WIRING BOARD - Google Patents

Description

  The present invention relates to a method for manufacturing a wiring board and a connection wiring board. In particular, the present invention relates to a technique for manufacturing an organic wiring board in which electrical connection is made between a terminal on the front side of the substrate and a terminal on the back side of the substrate through a through hole.

  As a multilayer wiring board used for chip connection such as IC or LSI, an organic wiring board having a structure in which dielectric layers made of a polymer material and conductor layers are alternately laminated is well known. Terminals for mounting the semiconductor chip directly or via an intermediate substrate are formed on one main surface side of such a wiring substrate. On the other main surface side, a terminal for connecting the wiring board to another board such as a mother board is formed.

  In the recent mainstream build-up wiring boards, in order to provide a support function for the build-up layer, a plate-like core formed with plated through holes is arranged at the center. The terminal on the front side of the substrate and the terminal on the back side are electrically connected through a plated through hole provided in the plate-like core. The plated through hole is filled with resin.

  As a method of filling the plated through hole with resin, a printing method using a mask is generally used. However, in a drying process after filling the resin, a so-called bleed-out phenomenon occurs in which a portion protruding from the substrate surface spreads out of the resin paste filled in the plated through hole. When a bleed-out phenomenon occurs and the resin paste amount in the plated through hole is reduced and dried and hardened, a dent is generated at the plated through hole position. The protruding portion can be flattened by polishing, but it is very troublesome to improve the dent. Also, if the dent remains, it will adversely affect the formation of the build-up layer, so it cannot be left alone.

Therefore, as shown in Patent Documents 1 to 3 below, a technique for preventing a bleed-out phenomenon by printing a resin paste around plated through holes and vias has been proposed. In fact, it has been found that the bleed-out phenomenon can be effectively suppressed by employing this technique.
JP 2000-124604 A JP 2001-7514 A JP 2001-203439 A

  Recently, however, there have been cases where dents cannot be completely prevented by simply printing a resin paste around the plated through hole. When the present inventors examined the cause in detail, the following knowledge was obtained. That is, as shown in FIG. 9, after the plating through hole 91 is filled with the resin paste 92, the resin paste 92 flows out to the back side along with the bleed-out phenomenon to the printing side. When the dummy resin printing part 92k is provided around the through hole, the effect of preventing the flow out to the back side is insufficient. This problem is particularly noticeable in regions where through holes are sparse.

  Up to now, since the through-hole diameter was large and a resin paste having a relatively high viscosity could be used, it is considered that the problem of flowing out to the back side did not surface. As the fine pitch of the wiring board has progressed, the through-hole diameter tends to decrease, and the need to use a low-viscosity resin paste with excellent filling properties has arisen. Accordingly, there is an urgent need not only to suppress the bleed out phenomenon on the front surface side, but also to take measures against the flow out to the back surface side.

  In view of the above circumstances, the present invention provides a method for manufacturing a wiring board that can prevent the formation of a dent due to the resin paste flowing out in the process of filling a through hole with a resin, and does not hinder the subsequent build-up process. The issue is to provide. It is another object of the present invention to provide a connection wiring board in which through-holes are reliably filled with resin and have excellent surface flatness.

Means for Solving the Problems and Effects of the Invention

The present invention for solving the above-Ru are arranged so as to closely spacing the through holes adjacent to each other penetrating in the thickness direction over the whole inside of the product part to be a wiring board (A) a wiring board work A through-hole forming region is formed, and a through-hole conductor is provided on the inner side of the through-hole to carry out a conductive connection between the front-side terminal and the back-side terminal of the wiring board, and the product part is to be separated from the product part. wherein the through hole forming the non-product portion surrounding the region, with to such a row of several along the periphery of the through-hole forming region of the product portion, conduction of the surface-side terminals and the back-side terminals Forming a dummy through hole not used for connection; (B) filling the through hole and the dummy through hole with a resin paste; and (C) the above Curing the fat paste is mainly characterized in that it comprises a.

  As explained above, when resin paste is filled into the through hole, and then dried and cured, the resin paste is removed from the wiring board workpiece (specific example: plate core) until the resin paste is sufficiently cured. It spreads out and flows out. It has already been explained that the wetting spread and the outflow occur on both sides. On the other hand, according to the present invention, by providing the dummy through hole, it is possible to reduce the area where the formation density of the through hole is sparse. As shown in FIG. 4, when the through holes 12, 12, 51 are formed densely, the wetting spread / flow-out of the resin paste 31 from the adjacent through holes 12, 12 interferes with each other and the blocking action works. It becomes like this. However, as in the rightmost through hole 51 in FIG. 4, when there is no other through hole adjacent to the hole, the blocking action is insufficient, and a dent HW is inevitably generated. A feature of the present invention is that the through hole 51 in which the dent HW is generated is a dummy through hole 51. In short, sacrificing the dummy through hole 51 prevents the through holes 12 and 12 that play an important role in the final product from being recessed. Thereby, when building up a dielectric material layer and a conductor layer on top, formation accuracy of these dielectric material layers and a conductor layer can be made favorable.

  Specifically, the above-described wiring board workpiece can be configured to include a product part to be a wiring board and a non-product part to be separated from the product part. In this case, a dummy through hole may be formed in the non-product part. Even if a dent is formed in the dummy through hole, it is a non-product part that is finally removed by cutting or the like, and thus there is no effect on the product part.

  Further, the product portion described above has a through hole forming region in which the through holes are densely arranged at regular intervals. And a dummy through hole can be provided in a non-product part so that the row | line surrounding this may be made along the circumference | surroundings of the through hole formation area | region. As described above with reference to FIG. 4, the dent is likely to occur in a through hole that is not surrounded by other through holes. That is, even in a product part in which through holes are formed relatively densely, a dent is likely to occur in the end hole. Therefore, if a dummy through hole is provided so as to surround the through hole formation region of the product part, the dent suppression effect can be sufficiently obtained even for the through hole at the extreme end of the through hole formation region.

  Further, the blocking action of the resin paste cannot be sufficiently obtained unless the through holes are dense to some extent. Therefore, the dummy through hole formation interval may be adjusted in accordance with the through hole formation interval. However, if the formation interval of the dummy through holes is too small, the formation of the dummy through holes itself may be difficult, and filling of the resin paste may be difficult. For these reasons, it is desirable to adjust the formation interval of the dummy through holes to be larger than 0.3d and not more than 2.8d with respect to the shortest formation interval d between adjacent through holes.

  If a plurality of rows of dummy through holes are provided, an effect of blocking the flow of the resin paste can be obtained more effectively, and the dent suppressing effect is enhanced. Further, if the dummy through holes are provided not only in a plurality of rows but also in a staggered pattern, a higher dent suppressing effect can be expected.

  In another preferred embodiment, the product section described above has a form in which a plurality of unit workpieces which are to be individual wiring boards are integrated in a lattice shape. Then, a frame-like non-product part can be provided so as to surround the product part from the periphery, and a dummy through hole can be provided only in the non-product part. Generally, as a method of manufacturing a wiring board, a method of manufacturing a plurality of wiring boards in a large format and cutting them into individual wiring boards at the end of the process is employed. According to this method, the frame-shaped non-product part is provided on the outer peripheral part of the wiring board workpiece being manufactured. Since the through holes are originally densely formed in the product portion, the function of blocking the flow of the resin paste is sufficient, and it can be said that it is not particularly necessary to provide dummy through holes. Rather, it may be difficult to provide a dummy through hole in the product part due to a design problem. Therefore, it is desirable to provide a dummy through hole only in a non-product part facing the through hole at the end which tends to be insufficient for blocking the flow of the resin paste. In addition, since the non-product part is a part that is finally cut and removed, it is an optimum part for providing a dummy through hole. Of course, if the design allows, a dummy through hole may be provided in the product portion.

The connection wiring board obtained by the manufacturing method as described above is as follows. That is, a product part in which a plurality of wiring boards sharing a plate-like core are arranged in a grid pattern, and the product part and the plate-like core are shared and integrated, and are provided in a form surrounding the product part. and a frame-like non-product portion, the through-hole forming region interval through holes are adjacent to each other penetrating it in the thickness direction in the plate-shaped core is arranged so as to be dense in the interior entire region of the product portion In the through hole, a through hole conductor responsible for conducting connection between the front surface side terminal and the back surface side terminal of the wiring board is provided together with a resin hole filling material, while surrounding the through hole forming region of the product portion. wherein the said plate-like core of the non-product portion a plurality of rows surrounding the product portion along the periphery of the through-hole forming region, using the conductive connection of the surface-side terminals and the back-side terminals The resin filling material dummy through hole is formed is mainly characterized in that it is filled not.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 schematically shows a cross-sectional structure of a wiring board 1 obtained by the present invention. The wiring board 1 has a predetermined pattern on both surfaces of a plate-like core 2 made of a heat-resistant resin plate (for example, bismaleimide-triazine resin plate) or a fiber reinforced resin plate (for example, glass fiber reinforced epoxy resin). Core conductor layers M1 and M11 (also simply referred to as conductor layers) forming wiring metal layers are formed. These core conductor layers M1 and M11 are formed as a plane conductor pattern that covers most of the surface of the plate-like core 2, and are used as a power supply layer or a ground layer. On the other hand, a through-hole 12 drilled by a drill or the like is formed in the plate-like core 2, and a through-hole conductor 30 that connects the core conductor layers M 1 and M 11 to each other is formed on the inner wall surface thereof. The through hole 12 is filled with a resin hole filling material 31 such as an epoxy resin.

  In addition, first dielectric layers (build-up layers) V1 and V11 made of the thermosetting resin composition 6 are formed on the upper layers of the core conductor layers M1 and M11, respectively. Further, first conductor layers M2 and M12 each having a metal wiring 7 are formed on the surface by Cu plating. The core conductor layers M1 and M11 and the first conductor layers M2 and M12 are interconnected by vias 34, respectively. Similarly, second dielectric layers (build-up layers) V2 and V12 using the thermosetting resin composition 6 are formed on the first conductor layers M2 and M12, respectively. On the surface, second conductor layers M3 and M13 having metal terminal pads 10 and 17 are formed. The first conductor layers M2, M12 and the second conductor layers M3, M13 are connected to each other by vias 34. The via 34 includes a via hole 34h, a via conductor 34s provided on the inner peripheral surface thereof, a via pad 34p provided so as to be electrically connected to the via conductor 34s on the bottom surface side, and a via conductor 34h on the opposite side to the via pad 34p. A via land 341 projecting outward from the periphery of the opening.

  On the first main surface MP1 of the plate-like core 2, the core conductor layer M1, the first dielectric layer V1, the first conductor layer M2, and the second dielectric layer V2 form the first wiring laminated portion L1. . On the second main surface MP2 of the plate-like core 2, the core conductor layer M11, the first dielectric layer V11, the first conductor layer M12, and the second dielectric layer V12 form the second wiring laminated portion L2. ing. In either case, dielectric layers and conductor layers are alternately laminated so that the first main surface CP is formed of the dielectric layer 6. Metal terminal pads 10 and 17 are respectively formed. The metal terminal pad 10 on the first wiring laminated portion L1 side constitutes a solder land 10 for flip-chip connection of an integrated circuit chip or the like. Further, the metal terminal pad 17 on the second wiring laminated portion L2 side is a back surface land (PGA pad, BGA pad) for connecting the wiring board itself to a mother board or the like by a pin grid array (PGA) or a ball grid array (BGA). It is used as.

  Solder lands 10 are arranged in a lattice pattern at a substantially central portion of the first main surface of the wiring substrate 1 and form chip mounting portions together with solder bumps 11 formed thereon. The back surface lands 17 in the second conductor layer M13 are also arranged in a lattice pattern. Solder resist layers 8 and 18 (SR1 and SR11) made of a photosensitive or thermosetting resin composition are formed on the second conductor layers M3 and M13, respectively. In any case, in order to expose the solder land 10 or the back surface land 17, the openings 8 a and 18 a are formed in a one-to-one correspondence with each land. The solder bump 11 of the solder resist layer 8 formed on the first wiring laminated portion L1 side is made of, for example, solder that does not substantially contain Pb, such as Sn—Ag, Sn—Cu, Sn—Ag—Cu, and Sn—Sb. Can be configured. On the other hand, the metal terminal pad 17 on the second wiring laminated portion L2 side is configured to be exposed in the opening 18a of the solder resist layer 18.

  The wiring board 1 can be manufactured by forming the wiring laminated portions L1 and L2 on both main surfaces MP1 and MP2 of the plate-like core 2 by a known build-up method or the like. Before performing the build-up process for forming the wiring laminated portions L1 and L2, the through-hole 12 is provided in the plate-like core 2 in advance, and the through-hole conductor 30 is formed in the through-hole 12 by plating. Fill. This will be specifically described below.

  First, as shown in FIG. 3 (3-1), a metal foil such as a Cu foil 2a was formed on both surfaces of a fiber reinforced resin plate or the like as a plate-like core 2 having a function of supporting the wiring laminated portions L1 and L2. Prepare things. However, the Cu foil 2a is not essential before the through hole is formed. The plate-like core 2 is composed of a product part 39 that finally becomes a product and a non-product part 41 as a disposal allowance that does not become a product. The planned cutting line DL is the boundary between the product part 39 and the non-product part 41.

  As shown in FIG. 3 (3-2), through holes 12 and 12 are formed in the product portion 39 of the plate-like core 2. Similarly, a through hole 51 is formed in the non-product portion 41. The through hole 51 of the non-product portion 41 is a dummy through hole 51 that is not included in the wiring substrate 1 that is the final product. The dummy through hole 51 is provided with the aim of preventing the resin paste in the through hole 12 of the product part 39 from spreading or flowing out by being filled with the resin paste in the same manner as the through hole 12.

  The through hole 12 and the dummy through hole 51 can be drilled with a drill or a laser. The diameter of the through hole 12 can be, for example, not less than 50 μm and not more than 550 μm. In the present embodiment, the diameter of the through hole 12 is about 300 μm, and the diameter of the dummy through hole 51 is also the same. After the perforating process is performed in this manner, a desmear process for removing the smear (residue) by cleaning the inside of the through hole 12 and the dummy through hole 51 with a chemical solution is performed. Thereafter, the through-hole conductor 30 is formed by electroless Cu plating and electrolytic Cu plating. However, the through-hole conductor 30 may be formed only by electroless Cu plating.

  Next, in a state where the plate-like core 2 is kept substantially horizontal, a metal mask 53 is overlaid on one main surface thereof. The metal mask 53 is aligned so that the opening pattern matches the through hole 12 and the dummy through hole 51 of the plate-like core 2. The opening diameter of the metal mask is preferably adjusted to be slightly larger than the diameters of the through hole 12 and the dummy through hole 51. Then, the resin paste 31 is filled into the through hole 12 and the dummy through hole 51 at once using a printing tool such as a squeegee (not shown). Even if a dummy through hole is provided, the labor of printing does not change.

  The plate-like core 2 is subjected to a printing process in a state where the non-product portion 41 is supported by the jig 57 and is floated from the work table 58. This makes it difficult for bubbles to be caught in the through hole 12 and the dummy through hole 51. Further, since the resin paste 31 does not adhere to the work table 58, the labor of cleaning can be saved. In this embodiment, the resin paste 31 is filled using the metal mask 53, but a direct filling method without using the metas mask 53 can also be employed.

  The resin paste 31 is not particularly limited as long as it can fill and fill the through holes 12 and the dummy through holes 51, but preferably has a thermal expansion coefficient similar to that of the plate core 2. This is because the generation of thermal stress can be reduced. Further, as described above, in the resin curing step, the resin surface in the through-hole 12 and the dummy through-hole 51 has less thermosetting shrinkage in order to suppress as much as possible that the surface of the resin is recessed from the surface of the plate core 2. For example, an epoxy resin, a polyimide resin, a BT resin, or the like can be appropriately selected and used.

  Further, the resin paste 31 should be uniformly filled in the through-hole 12 and the dummy through-hole 51, be free from entrainment of bubbles, and have physical properties so as not to swell, crack or peel off later. is important. The viscosity characteristic that greatly affects the ease of filling can be adjusted by mixing an inorganic powder such as silica or alumina into the resin paste 31. In addition, instead of insulating inorganic powders such as silica and alumina, or conductive powders such as Cu powder and Ag powder may be contained together with these, the resin paste 31 may be provided with conductivity.

  When the filling of the resin paste 31 into the through hole 12 and the dummy through hole 51 is completed, the filled resin paste 31 is dried and cured. The step of drying and curing the resin paste 31 can be performed by leaving the plate-like core 2 in an atmosphere (eg, 130 ° C.) heated from room temperature. This step may be performed with the side filled with the resin paste 31 facing up and the plate-like core 2 kept substantially horizontal. If it is slanted, the effect of preventing the occurrence of dents cannot be obtained sufficiently.

  As shown in FIG. 4 (4-1), immediately after the resin paste filling process of FIG. 3 is finished, the resin paste 31 filled in the through holes 12 and the dummy through holes 51 is approximately the thickness of the metal mask 53 (for example, About 100 μm), which rises from the surface of the plate-like core 2, but wets and spreads to the upper surface side and flows out to the lower surface side until it is sufficiently dried and cured. If the resin paste 31 is a thermosetting type, when placed in a heated atmosphere, the resin paste 31 fluidizes once and then hardens, so that wetting and spreading are likely to occur at that time.

  In the present invention, since the dummy through hole 51 is provided so that the distance between the through hole 12 and the dummy through hole 51 is close, the resin paste 31 is actively wet from the through hole 12 of the product portion 39. It can be prevented from spreading or flowing out. As a result, as shown in FIG. 4 (4-2), since the dummy through hole 51 is not surrounded by other through holes, the outflow amount of the filled resin paste 31 increases and the dent HW is likely to occur. Become. On the other hand, in the product portion 39, the main surface of the plate-shaped core 2 is immediately covered with the resin paste 31, so that the resin paste 12 filled in the through holes 12 is not so small and no dent is generated.

  In this embodiment, the plate core 2 is placed in a heated atmosphere so that the resin paste 31 is dried and cured. However, depending on the composition adjustment of the resin paste 31, it can be naturally dried at room temperature. It is.

  In FIG. 5, the whole schematic diagram of the plate-shaped core 2 is shown. As can be seen from FIG. 5, the product section 39 includes a plurality of unit workpieces 1 a that are to be individual wiring boards 1 arranged in a lattice pattern. All the unit works 1a share a single plate-like core 2, and the planned cutting line DL is the boundary between the individual unit works 1a. Further, a frame-like non-product part 41 is provided so as to surround the product part 39. The dummy through hole 51 described with reference to FIGS. 3 and 4 is provided only in the non-product portion 41. By providing only in the non-product part 41, it is not necessary to change the design of the wiring board 1 as a product.

  Further, fine points in FIG. 5 represent the through hole 12 and the dummy through hole 51. As can be seen from this, in this embodiment, dummy through holes 51 are formed around the entire product portion 39. The product portion 39 constitutes a through hole forming region in which the through holes 12 are densely arranged. As shown in FIG. 6, dummy through holes 51 are provided in the non-product portion 41 so as to form a row surrounding the through hole forming region (product portion 39). According to such a configuration, all the through holes 12 of the product portion 39 are located on the other sides of the other through holes 12 or the dummy through holes 51, and as a result, the blocking action of the resin paste 31 is all the through holes. 12 will work.

  As shown in FIG. 6, the dummy through holes 51 may be provided in a plurality of rows along the outer periphery of the product portion 39. By doing so, it is possible to more effectively suppress the spread and wetting of the resin paste 31. However, in consideration of cost effectiveness, this embodiment having two rows is preferable.

Further, the formation interval of the dummy through holes 51 can be set as follows. As shown in FIG. 7, when the formation interval of the through holes 12 in the through hole formation region (product part 39) is d ₁ and the formation interval of the dummy through holes 51 is d ₂ , 0.3d ₁ <d ₂ ≦ 2. 8d ₁ can be set. The formation interval d ₁ of the through hole 12 is intended to mean the centers of adjacent through holes 12, 12 (between the axes) distance. The same applies to the dummy through hole 51. If the dummy through hole 51 is positioned within such a range, the blocking action of the resin paste 31 can be imparted to the through hole 12 on the opposite side across the planned cutting line DL without excess or deficiency.

  The through hole 12 and the dummy through hole 51 can be arranged so as to be symmetric with respect to the planned cutting line DL. That is, the dummy through hole 51 may be provided at a position that is a mirror image of the through hole 12 of the product portion 39 arranged along the planned cutting line DL except for a portion located at the corner. In this way, it is possible to effectively suppress wetting and spreading of the resin paste 31 in the through hole 12 of the product portion 39.

  6 and 7 show an example in which the through holes 12 of the product portion 39 are regularly formed. However, the formation form of the through holes 12 is mixed with a regular region and an irregular region. Sometimes. In such a case, the formation form of the dummy through hole 51 does not depend on the formation form of the through hole 12 of the product part 39, and it is preferable to provide them at a constant interval from the viewpoint of design easiness. Of course, the formation interval of the dummy through holes 51 may be changed according to the density of the through holes 12 of the product portion 39. Even in these cases, the dummy through holes 51 are preferably arranged in a plurality of rows.

  As described above, after the step of filling and curing the resin paste 31, the surface of the plate core 2 is polished, and the resin surface in the through hole 12 and the dummy through hole 51 and the plate core 2 are polished. It is processed so that the surface of the surface becomes flush. Thereafter, the Cu foil 2a on the surface of the plate-like core 2 is patterned to form the core conductor layers M1 and M11. Then, the first wiring laminated portion L1 and the second wiring laminated portion L2 are formed by a known build-up method. Further, solder resist layers SR1 and SR11 are formed, and Ni / Au plating is applied to the conductor layers M3 and M13 exposed in the openings 8a and 18a of the solder resist layers SR1 and SR11, whereby terminal pads 10 and 17 are obtained. After completion of the Ni / Au plating process, a lead-free solder paste such as Sn—Ag—Cu is filled in the opening 8a of the solder resist layer SR1, and a reflow process is performed. As a result, solder bumps 11 are formed on the terminal pads 10.

  The step of patterning the Cu foil 2a to form the core conductor layers M1 and M11 can be performed prior to the resin paste filling step described with reference to FIGS. According to this method, irregularities are formed on the surface of the plate-like core 2 as much as the patterns of the core conductor layers M1 and M11 are formed, thereby making it possible to weaken the action of spreading and flowing out of the resin paste 31. Therefore, it is preferable.

  By performing the above steps, it is possible to obtain a connection wiring substrate 100 in which a plurality of wiring substrates 1 are arranged in a lattice pattern. The connection wiring board 100 includes a product part 39 ′ composed of the wiring board 1 and a non-product part 41 ′ around the product part 39 ′. The non-product portion 41 ′ is integrated with the product portion 39 ′ and the plate-like core 2, and is provided in a form surrounding the product portion 39 ′. The non-product portion 39 'is necessary for handling and fixing the workpiece in the manufacturing process. As already described, the dummy through hole 51 is formed in the portion of the plate-like core 2 of the non-product portion 41 ′ and filled with the resin hole filling material 31. The connection wiring board 100 is cut along a predetermined planned cutting line DL and divided into individual wiring boards 1. The non-product part 41 is separated from the wiring board 1.

  In the above description, the connection wiring board 100 having many wiring boards 1 is taken as an example. Then, it has been described that the dummy through holes 51 are provided so as to form a row surrounding the entire product portion 39 ′. However, if there is enough space, it is possible to provide the dummy through holes 51 so as to surround individual product parts. As shown in FIG. 8, for the plate-like core 22 in which the workpiece 1b that finally becomes one product is surrounded by the non-product portion 45, dummy through holes 51 are formed so as to surround each workpiece 1b. Such a form is preferable.

Experimental example

  In order to confirm the effect of the dummy through hole, the following test was conducted. First, a known copper-clad laminate (resin thickness 800 μm, Cu thickness 25 μm) is prepared as a plate-like core, and through holes are provided at intervals of 0.6 mm in product parts (100 pieces), and non-product parts are provided in non-product parts. Dummy through holes were formed at intervals of 2.0 mm or 1.0 mm. In addition, about the plate-shaped core of the formation space | interval of 1.0 mm, what provided the dummy through hole by 1 row-3 rows was produced, respectively. For comparison, a plate core without dummy through holes was also produced in the same manner.

  Next, resin paste (silica filler-containing epoxy resin) was filled into the through holes and the dummy through holes by a printing method using a metal mask for all the plate-like cores. Thereafter, the resin paste was dried and cured at 130 ° C. in a drying furnace with the printed side up. Then, select 35 unit workpieces located on the outermost periphery of the product part as test pieces, and check whether there are dents in the through holes and dummy through holes (determined by whether they are recessed from the surface of the plate core) Was confirmed with a magnifying glass. The results are shown in Table 1.

  Table 1 summarizes the number of test pieces in which dents of through holes and dummy through holes were recognized. As for the test piece which does not provide a dummy through hole, generation | occurrence | production of the dent of the through hole was recognized by all 35 products. On the other hand, in the test piece provided with the dummy through hole, the dent of the through hole in the product portion was reduced or no dent was generated. In particular, when two or more rows of dummy through holes were provided, no dent was generated in the through holes in the product portion. From the viewpoint of manufacturing cost, it can be said that the dummy through holes are most preferably two rows.

The figure which shows an example of the cross-section of a wiring board. The schematic diagram of a connection wiring board. Manufacturing process explanatory drawing of a wiring board. Manufacturing process explanatory drawing following FIG. The schematic diagram of a plate-shaped core. The schematic diagram which shows the formation form of a dummy through hole. The enlarged view of FIG. The schematic diagram which shows another embodiment. The figure explaining the problem of the conventional method.

Explanation of symbols

1 Wiring board 1a, 1b Unit work 2, 22 Plate core 10 Terminal pad (surface side terminal)
12 Through hole 17 Terminal pad (Back side terminal)
30 Through-hole conductor 31 Resin paste (resin filling material)
39 Product part 41, 45 Non-product part 51 Dummy through hole 100 Connection wiring board DL Cutting line HW Depression

Claims (6)

(A) together with the interval through holes are adjacent to each other penetrating in the thickness direction over the whole inside of the product part to be a wiring substrate of the wiring substrate workpiece to form a through-hole forming region that will be arranged so as to be dense, the through The non-product that includes a through-hole conductor that is in charge of electrical connection between the front-side terminal and the back-side terminal of the wiring board inside the hole, and surrounds the through-hole forming region of the product part that is to be separated from the product part the parts, with to such a row of several along the periphery of the through-hole forming region of the product portion, the step of forming a dummy through hole which is not used for conductive connection of the surface-side terminals and the back-side terminals When,
(B) filling the resin paste into the through hole and the dummy through hole;
(C) curing the resin paste ;
A method for manufacturing a wiring board, comprising:   The method of manufacturing a wiring board according to claim 1, wherein dummy through holes are formed so as to surround individual product portions of the product portion.   3. The wiring according to claim 1, wherein the formation interval of the dummy through holes is adjusted to be greater than 0.3 d and less than or equal to 2.8 d with respect to the shortest formation interval d between the adjacent through holes in the through hole formation region. A method for manufacturing a substrate.   The product part has a form in which a plurality of unit workpieces that are to be the individual wiring boards are integrated in a grid shape, and the frame-like non-product part is formed so as to surround the product part from the periphery. The method for manufacturing a wiring board according to claim 1, wherein the dummy through hole is provided only in the non-product part. A product part in which a plurality of wiring boards sharing a plate-like core are arranged in a grid, and a frame shape provided in a form that is integrated with the product part and the plate-like core and surrounds the periphery of the product part A non-product portion, and the plate-like core in the entire interior of the product portion has a through-hole forming region in which through-holes penetrating in the thickness direction are arranged so as to be closely spaced from each other. In the through hole, a through hole conductor responsible for conducting connection between the front surface side terminal and the back surface side terminal of the wiring board is provided together with a resin filling material, while the non- hole surrounding the through hole forming region of the product portion is provided. the said plate-shaped core of the product portion a plurality of rows surrounding the product portion along the periphery of the through-hole forming region, is not used for conductive connection of the surface-side terminals and the back-side terminals da Connecting wiring board in which the resin filling material over the through hole is formed is characterized in that it is filled.   The connection wiring board according to claim 5, wherein dummy through holes are provided so as to surround individual product parts of the product part.

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