JP4776576B2 - Printed wiring board - Google Patents

Description

  The present invention relates to a printed wiring board having a laminated insulating layer and a conductor layer, and having a through hole for inserting a press-fit connection terminal.

In recent years, for example, as the performance of electronic devices mounted on vehicles has improved, the components to be mounted have been reduced in size and weight. As a means for achieving the reduction in size and weight of such components, there is an increasing demand for reduction in size and weight of the connector for connecting each module, and a press-fit connection structure is known as an effective means for reducing the size and weight of this connector. (For example, see Patent Document 1 and Patent Document 2).
JP 2005-353567 A JP 2004-273256 A

  The so-called press-fit connection using press-fit connection terminals is an excellent connection method that can be electrically and mechanically bonded without using a bonding agent such as solder by simply inserting a specially shaped terminal into the through hole of the printed wiring board. . However, as a result of intensive observation and analysis of past usage examples, the inventors found the following problems in most cases.

  First, as a first problem, when a press-fit connection terminal is inserted into the through hole of the printed wiring board, the terminal is inserted into the insulating resin layer of the printed wiring board through the plated layer wall of the through hole near the terminal insertion opening. When force is applied, a crack is generated between the glass fiber and the resin in the insulating resin layer of the printed wiring board.

  FIG. 7 is a sectional view showing the crack between the glass fiber and the resin in an easy-to-understand manner. The inside of the insulating layer 520 is filled between the glass fiber 520a in the warp knitting direction and the glass fiber 520b in the weft knitting direction. It can be seen that the glass fiber is peeled (delamination) D in the glass fiber.

  FIG. 8 shows a state in which press-fit connection terminals T (T1, T2,...) Are inserted into the conventional printed wiring board 5, and through holes 530 (531, 532) are formed in the insulating layer 520 at a predetermined narrow interval. ,... Are formed, and press-fit connection terminals T (T1, T2...) Are inserted from the upper through-hole lands 530a (531a, 532a,...).

  On the other hand, FIG. 9 shows a problem of the conventional example that may actually occur. When the through hole 530 (531, 532,...) Is formed adjacent to the insulating layer 520, the press-fit connection terminal T ( T1, T2,...) Are inserted from the terminal insertion port of the upper through-hole land 530a (531a, 532a,...), So that between the glass fiber and the resin in the vicinity of the through-hole terminal insertion port of the insulating layer 520. It can be seen that peeling D occurs.

When cracks between the glass fibers and resin in the insulating resin layer of such a printed circuit board occurs, to lower the insulation resistance of the printed wiring board absorbs moisture from the portion of the crack in an environment of high temperature and high humidity.

  Another problem is that the press-fit connection terminal pushes up the glass fiber through the wall of the through-hole plating layer near the terminal insertion port of the through-hole of the printed wiring board, and the through-hole land formed in the outer layer is removed. The point made to peel is mentioned.

  In press-fit connection, a plurality of press-fit connection terminals are generally used for connector connection without being used alone for one printed wiring board. However, in this case, the distance between the adjacent terminals is narrowed from 1 mm to 2.5 mm, and the above-mentioned problem is remarkable.

  In order to avoid such problems, conventionally, the following measures have been taken.

  For example, as described in Patent Literature 1 and Patent Literature 2, the first countermeasure is a countermeasure for changing the structure of the press-fit connection terminal so that uneven stress is not applied to the plating layer.

  The second countermeasure is to reduce the force applied to the wall surface of the through-hole when inserting the terminal by making the insertion angle of the insertion guide portion of the terminal gentle, or by reducing the surface roughness of the press-fit terminal to the through-hole. This is a measure for minimizing the stress acting between the terminal and the through hole, such as reducing the friction between the terminal and the through hole when the terminal is inserted.

  A third measure is to provide a taper in the vicinity of the press-fit connection terminal insertion opening of the through hole of the printed wiring board, and reduce the contact of the press-fit connection terminal in the vicinity of the terminal insertion opening, thereby reducing the terminal insertion force. It is a measure to disperse.

  Even when the above measures are taken, in the press-fit connection in which a large number of press-fit connection terminals are press-fitted into through-holes formed at narrow intervals, the respective terminal insertion forces are superimposed on each other. Therefore, the insulating resin layer between the terminals is more than twice as stress as the single terminal, and the glass fiber and the resin in the insulating resin layer are cracked. Don't be.

  In view of these points, there is an example in which the countermeasure is to use an insulating material that is stronger than a material generally used for a resin layer of a printed wiring board. However, such a measure uses an insulating material that is more expensive than a general printed wiring board material, which increases the cost of the printed wiring board itself and is not appropriate. That is, each attempt as described above cannot be a sufficient measure for solving the problems of the present invention.

  An object of the present invention is to provide a printed wiring board which realizes prevention of peeling of an insulating resin layer and prevention of peeling of a through-hole land at a low cost when inserting a press-fit connection terminal.

In order to solve the above-mentioned problem, a printed wiring board according to claim 1 of the present invention is
A printed wiring board having a plurality of through holes for inserting a plurality of press-fit connection terminals in a predetermined region, having a laminated insulating layer and a conductor layer,
A reinforcing layer having a thickness of 0.2 mm or more is interposed between the plurality of through holes inside the insulating layer, and at least a part of the reinforcing layer interposed between the through holes is at least one of the through holes. It is characterized by being connected . At this time, a metal core may be used as the reinforcing layer.

  The printed wiring board according to claim 1 of the present invention has such a reinforcing layer in the insulating layer of the printed wiring board, so that a plurality of press-fit connections are made to a plurality of through holes formed in a predetermined region of the printed wiring board. The region of the insulating layer affected by the terminal insertion force generated when inserting the terminal is reduced, and the separation of the insulating layer and the through-hole land due to the deformation of the insulating layer in this portion are prevented as much as possible.

Moreover, when a metal core is used as the reinforcing layer in the insulating layer, the printed wiring board according to the present invention can be manufactured in a normal printed wiring board manufacturing process without requiring a special manufacturing process.
In addition, by inserting at least part of the reinforcing layer with at least part of the through hole, terminal insertion that occurs when inserting a plurality of press-fit connection terminals into the plurality of through holes formed in a predetermined region of the printed wiring board The region of the insulating layer affected by the force is further reduced, and the peeling of the insulating layer in this portion and the peeling of the through-hole land due to the deformation of the insulating layer are prevented as much as possible.

Moreover, the printed wiring board according to claim 2 of the present invention is the printed wiring board according to claim 1,
At least a part of the conductor layer is made of an outer layer conductor, and the distance in the thickness direction from the outer layer conductor to the reinforcing layer is 0.3 mm or less . At this time, it is sufficient that a part of the reinforcing layer is directly below the outer layer conductor.

  By forming the reinforcing layer at such a position in the insulating layer, it is affected by the terminal insertion force generated when inserting a plurality of press-fit connection terminals into a plurality of through holes formed in a predetermined region of the printed wiring board. The region of the insulating layer to be received is further reduced, and the separation of the insulating layer in this portion and the separation of the through-hole land due to the deformation of the insulating layer are prevented as much as possible.

Further, by defining the distance from the outer layer conductor to the reinforcing layer to such a dimension, the region of the insulating layer that is affected by the effect of the present invention, that is, the terminal insertion force is further reduced, and the insulating layer is peeled off at this portion. The effect of preventing the peeling of through-hole lands accompanying deformation of the insulating layer as much as possible is exhibited.

Moreover, the printed wiring board according to claim 3 is the printed wiring board according to claim 1 or 2 ,
A distance between the reinforcing layer and the through hole in the radial direction of the through hole is 0.5 mm or less.

  By defining the distance between the reinforcing layer and the through hole in such a dimension, when inserting a plurality of press-fit connection terminals into a plurality of through holes formed in a predetermined region of the printed wiring board, these terminal insertion forces The region of the insulating layer affected by the above is further reduced, and the peeling of the insulating layer in this portion and the peeling of the through-hole land due to the deformation of the insulating layer are prevented as much as possible.

  According to the present invention, it is possible to provide a printed wiring board that realizes prevention of peeling of an insulating resin layer and prevention of peeling of a through-hole land at low cost when a press-fit connection terminal is inserted into a through-hole.

Hereinafter, a printed wiring board according to an embodiment of the present invention will be described. As shown in FIG. 1, the printed wiring board 1 according to an embodiment of the present invention is laminated on a reinforcing layer 111, insulating layers 121 and 122 that are sandwiched from both sides, and insulating layers 121 and 122, respectively. The printed wiring board includes the conductor layers 112 and 113 and the through holes 130 (131, 132,...) Into which the press-fit connection terminals T are inserted. A plurality of through holes 130 into which a plurality of press-fit connection terminals T (T1, T2,...) Are inserted are formed at predetermined intervals in a predetermined region of the printed wiring board 1, and are provided inside the insulating layer. A reinforcing layer 111 having a thickness of 0.2 mm or more is interposed between the through holes 130. Here, the reinforcing layer 111 is a metal core . In the present embodiment, the interval between adjacent through holes is 1 to 2.5 mm.

  More specifically, as shown in the figure, the insulating layers 121 and 122 of the printed wiring board 1 according to the present embodiment are composed of an upper insulating layer 121 and a lower insulating layer 122 that sandwich the reinforcing layer 111, and each of them is heated. It is made of a general glass epoxy resin called an FR-4 material having an expansion coefficient of 45 to 70 ppm. In the present embodiment, the thickness of each of the insulating layers 121 and 122 in FIG. 1 is 0.2 mm.

  The reinforcing layer 111 sandwiched between the insulating layers of the printed wiring board 1 uses a metal core made of a rolled copper foil having a thickness of 0.2 to 0.4 mm. In addition, between the reinforcing layer 111 and the insulating layers 121 and 122, a known roughening process is performed on the surface to produce an anchor effect and firmly adhere.

  In the reinforcing layer 111, through holes 111a, 111b,... For forming through holes are opened, and a printed wiring board is manufactured between the prepared holes 111a, 111b,. It is embedded with a resin material that has flowed out of the insulating layer during substrate pressing. In addition, the distance (A11, A12, ... in FIG. 1) between the pilot holes 111a, 111b, ... of the reinforcement layer 111 and the metal plating 140 of the through hole 130 is 0.5 mm or less.

  Further, outer layer conductors 112 and 113 made of electrolytic copper foil are laminated outside the insulating layers 121 and 122. The outer layer conductors 112 and 113 are formed in a predetermined circuit pattern by a known etching process, and as shown in FIG. 1, the upper and lower outer layer conductors are connected to each other through a metal plating 140 of a through hole. In FIG. 1, the outer layer conductors 112 and 113 are shown as through-hole lands 130a (131a, 132a,...), And the reinforcing layer 111 and the metal plating 140 of the through-hole 130 are not connected.

  For example, a large number of through-holes 130 are formed at predetermined intervals in a predetermined region of the printed wiring board 1 in order to form a connector portion on the printed wiring board 1, and as shown in FIG. T2,... Are inserted into the through holes 130 (131, 132,...) From one substrate surface side (above the substrate in FIG. 1).

  The distances (B11, B12,... In FIG. 1) between the surface of the outer layer conductor 112 on the press-fit connection terminal insertion side, that is, the surface of the through-hole land 130a, and the press-fit connection terminal insertion side surface of the reinforcing layer 111 are as follows. 0.3 mm.

  In addition, in this embodiment, the inner diameter of the through hole 130 (131, 132,...) Is 1.0 mm, a metal plating 140 having a thickness of 0.05 mm is applied, and a press fit having an outer diameter of 1.1 mm. The connection terminal is inserted into the through hole in a press-fit state. Moreover, the diameter of the through-hole land 130a (131a, 132a, ...) of the through-hole 130 is 1.6 mm in this embodiment.

  Then, the manufacturing method of the printed wiring board 1 which has this structure is demonstrated. 2A to 2I are side cross-sectional views for explaining a method for manufacturing the printed wiring board 1. First, as shown in FIG. 2A, a reinforcing layer 111 made of rolled copper foil having a thickness of 0.2 to 0.4 mm is prepared. As shown in FIG. 2B, the front and back surfaces of the reinforcing layer 111 are prepared. , And circuit patterns are formed by etching, punching, or the like. Here, the hole diameter d of the through holes 111a, 111b,... For the through hole of the reinforcing layer 111 is such that the distance between the through hole and the lower hole of the reinforcing layer is 0.5 mm or less when the through hole is completed. And As a method for forming the prepared hole in the reinforcing layer 111, a general prepared hole forming method such as press punching, drilling, or etching is used.

  Then, as shown in FIG.2 (c), both surfaces of the reinforcement layer 111 using the metal core which consists of rolled copper foil are roughened. As a method of forming a rough surface on the surface of the reinforcing layer 111, a method of forming an oxide on the surface of the reinforcing layer 111, as is generally performed in a method of manufacturing a printed wiring board, the shape of the oxide layer And reducing to metal copper with a reducing agent (see, for example, Japanese Patent No. 3395854), or a method of forming metal copper having a coarse particle diameter by electroless plating or electrolytic plating.

  2D, insulating layers 121 and 122 made of a resin having a thermal expansion coefficient of 45 to 70 ppm called a so-called FR-4 material having a thickness of 0.2 mm are stacked, and the insulating layers 121 and 122 are also laminated. The outer layer conductors 112 and 113 made of an electrolytic copper foil having a thickness of 70 μm are laminated on both sides, and are pressed in a heated state to integrate them as shown in FIG. At this time, the resin of the insulating layers 121 and 122 flows into the portions of the reinforcing layer 111 processed as through-hole pilot holes 111a, 111b,.

  Subsequently, as shown in FIG. 2 (f), through holes for through holes that penetrate the outer layer conductors 112 and 113 are formed.

  Subsequently, as shown in FIG. 2G, copper plating 140 is formed on the through holes and the outer layer conductors 112 and 113.

  Subsequently, as shown in FIG. 2H, the outer layer conductors 112 and 113 on both surfaces of the substrate are etched to form a circuit pattern.

  Subsequently, although not shown, the resist 150 is applied to the through hole for the through hole and the outer layer conductors 112 and 113 to complete the manufacture of the printed wiring board in which the through hole 130 is formed.

  Since the printed wiring board 1 according to the present embodiment has such a reinforcing layer 111 in the insulating layer of the printed wiring board 1, the reinforcing layer 111 serves as a reinforcing layer in the insulating layer, and the printed wiring board 1 The region of the insulating layer affected by the terminal insertion force generated when the plurality of press-fit connection terminals T are inserted into the plurality of through holes 130 formed in the predetermined region is reduced, and the insulating layer 121 is peeled off or insulated in this portion. The through-hole land 130a is prevented from being peeled off as much as possible due to the deformation of the layer 121.

  Further, by using the metal core as the reinforcing layer 111 in the insulating layer, the printed wiring board according to the present invention can be manufactured in a normal printed wiring board manufacturing process without requiring a special manufacturing process. Become. Further, it is not necessary to use a special press-fit connection terminal or a high-cost insulating material having sufficient strength as in the conventional case.

  Subsequently, various modified examples of the printed wiring board according to the above-described embodiment of the present invention will be described. In addition, about the structure equivalent to the above-mentioned embodiment, a corresponding code | symbol is attached | subjected and detailed description is abbreviate | omitted. As shown in FIG. 3, the printed wiring board 2 according to the first modification of the above-described embodiment includes a reinforcing layer 211 that is pressed out of the outer layer conductors 212 and 213 of the printed wiring board 2 via insulating layers 221 and 222. It is arranged directly under the outer layer conductor 212 on the fitting connection terminal insertion side. Specifically, the distance (B21, B22,... In FIG. 3) from the outer layer conductor 212 on the press-fit connection terminal insertion side of the printed wiring board 2 to the reinforcing layer 211 disposed immediately below the outer layer conductor is 0. It is smaller than 3 mm. Further, the distances (A21, A22,... In FIG. 3) between the prepared holes 211a, 211b,... Of the reinforcing layer 211 and the metal plating 240 of the through holes 230 (231, 232,. It is 0.5 mm or less.

  Since the printed wiring board 2 according to the first modification has such a configuration, the region of the insulating layer 221 that is affected by the terminal insertion force is further reduced, and the insulating layer 221 is peeled or the insulating layer 221 is deformed in this portion. The through-hole land 230a (231a, 232a,...) Accompanying the above is exerted as much as possible.

  Subsequently, a printed wiring board 3 according to a second modification of the above-described embodiment will be described. As shown in FIG. 4, the printed wiring board 3 according to the second modification includes a press-fit connection terminal of a through hole 330 (331, 332,...) In addition to one insulating layer 321 sandwiching the reinforcing layer 311. Two inner layer conductors 313 and 314 are laminated on the insulating layer opposite to the insertion side via three insulating layers 322, 323 and 324. The inner layer conductors 313 and 314 are electrically connected between the outer layer conductors 312 and 315 in any combination by the metal plating 340 of the through hole 330. Note that the distance from the outer layer conductor 312 on the press-fit connection terminal insertion side of the printed wiring board 3 to the reinforcing layer 311 disposed immediately below the outer layer conductor is smaller than 0.3 mm as in the first modification described above. Yes. Further, the distance between the reinforcing layer 311 and the through hole 310 is the same as that in the above-described embodiment and the first modified example.

  Even if the printed wiring board 3 according to the second modified example has such a configuration, the region of the insulating layer 321 affected by the terminal insertion force is further reduced, and the insulating layer 321 is peeled off or the insulating layer 321 in this portion. The through-hole lands 330a (331a, 332a,.

  Subsequently, a printed wiring board 4 according to a third modification of the above-described embodiment will be described. The printed wiring board 4 according to the third modification has a configuration in which a reinforcing layer 411 interposed between through holes is connected to a plurality of through holes 430 (431, 432,...) As shown in FIG. ing. The distance between the through-hole land 430 (431a, 432a,...) And the through-hole terminal entrance side surface of the reinforcing layer 411 is the same as in the above-described embodiment.

  Since the printed wiring board 4 according to the third modification has such a configuration, a plurality of press-fit connection terminals T (T1, T2,...) Are inserted into the plurality of through holes 430 formed in a predetermined region of the printed wiring board 4. The area of the insulating layer that is affected by the terminal insertion force generated when inserting ..) is further reduced, and through-hole lands 430a (431a, 432a,. ) Is prevented as much as possible.

  In this case, the reinforcing layer 411 does not need to be connected to all of the plurality of through holes 430, and the above-described effect is obtained even if a part of the reinforcing layer 411 is connected to at least one of the plurality of through holes 430. Can be played.

  Hereinafter, since the evaluation test which proves the usefulness of this invention was done, this test result is demonstrated. In the evaluation test of the present invention, various printed wiring boards corresponding to FIG. 1 were manufactured. Specifically, it is a printed wiring board in which the distance from the through hole of the reinforcing layer is 0 mm, 0.3 mm, 0.5 mm, 0.7 mm, and 1.0 mm, and the distance from the reinforcing layer to the through hole is different. Many printed wiring boards were manufactured. The specifications common to these printed wiring boards were as follows.

  The printed wiring board used is a glass epoxy resin insulating material made of FR-4 material having a thickness of 0.2 mm, a longitudinal elastic modulus of 25 GPa and a Poisson's ratio of 0.3, and an electrolytic copper foil of thickness 0.07 mm. An outer layer conductor made of The through-hole hole diameter was 1.0 mm, the press-fit terminal diameter was 1.1 mm, the press-fitting allowance was 0.1 mm, the through-hole plating thickness was 0.05 mm, and the land diameter was 1.6 mm. Moreover, the thickness of the whole printed wiring board was 1.05 mm.

  And after inserting the press fit connection terminal of the general structure mentioned above into these printed wiring boards, the thermal shock test of 3000 cycles which applied the thermal shock of -40 degreeC-120 degreeC was performed about these printed wiring boards, The printed wiring board was examined for the presence of peeling of the glass cloth in the vicinity of the through hole and for the peeling of the outer layer through hole land.

  Table 1 in FIG. 6 is a list showing the evaluation test results of each printed wiring board. At this time, the distance between the reinforcing layer and the through hole was 0.3 mm. As can be seen from the results of this evaluation test, the printed wiring board having a reinforcing layer thickness of 0 mm, that is, without the reinforcing layer, peeled off the glass cloth in the vicinity of the through hole after the evaluation test, and peeled off the through hole land of the outer layer. It was.

  Further, the printed wiring board having a reinforcing layer thickness of 0.1 mm had the glass cloth peeled off in the vicinity of the through hole after the evaluation test, and the outer layer through hole land was slightly peeled off.

  On the other hand, the printed wiring boards having the reinforcing layer thicknesses of 0.2 mm, 0.3 mm, and 0.4 mm did not peel off the glass cloth in the vicinity of the through hole after the evaluation test, and did not peel off the through hole land of the outer layer. .

  Further, Table 2 in FIG. 6 is a list showing the evaluation test results of each printed wiring board. The reinforcing layer of the printed wiring board at this time was a metal core made of a rolled copper foil having a thickness of 0.2 mm, a longitudinal elastic modulus of 118 GPa, and a Poisson's ratio of 0.33. As can be seen from the evaluation test results, the printed wiring board having a distance between the reinforcing layer and the through hole of 1.0 mm has the glass cloth peeling near the through hole after the evaluation test, and the through hole land of the outer layer is peeled off. there were.

  Further, the printed wiring board having a distance between the reinforcing layer and the through hole of 0.7 mm had peeling of the glass cloth in the vicinity of the through hole after the evaluation test, and slight peeling of the through hole land of the outer layer.

  On the other hand, printed wiring boards having a distance between the reinforcing layer and the through hole of 0.5 mm, 0.3 mm, and 0 mm have no peeling of the glass cloth in the vicinity of the through hole after the evaluation test, and no peeling of the through hole land of the outer layer. It was.

  From the above evaluation test results, a printed wiring board having the configuration of the present invention, that is, a plurality of through holes into which a plurality of press-fit connection terminals are inserted is formed in a predetermined region of the printed wiring board, and a plurality of through holes are formed inside the insulating layer. A printed wiring board having a configuration in which a reinforcing layer having a thickness of 0.2 mm to 0.4 mm is interposed between the through-holes and the distance between the reinforcing layer and the through-hole is 0.5 mm or less is used for press-fit connection terminal insertion. It was proved that the problem involved was solved.

  From the knowledge of the evaluation test, when inserting a plurality of press-fit connection terminals into a plurality of through holes of the printed wiring board to ensure the connection, a copper foil is provided between the through holes of the printed wiring board into which each terminal is inserted. It was found that by inserting a reinforcing layer such as a reinforcing layer, it was possible to greatly prevent damage during terminal insertion.

  Specifically, breakage of the through hole could be prevented by interposing a reinforcing layer having a thickness of 0.2 mm to 0.4 mm between the press-fit connecting terminal through holes.

  In addition, it turned out that the reinforcement layer may be connected to the through hole, or may be separated if the distance is within 0.5 mm.

  When the reinforcing layer is arranged so as to be offset toward the terminal insertion port side, it is considered that breakage of the through hole of the printed wiring board at the time of terminal insertion can be further greatly prevented.

  Further, even if the conductor layer has a three-layer structure, or even a multilayer structure of four or more layers, the thickness of the reinforcing layer is 0.2 mm to 0.4 mm, and 0.3 mm from the through-hole land on the press-fit connection terminal insertion side. The same effect can be expected if the through hole insertion side surface of the reinforcing layer is disposed within.

  As described above, according to the present invention, it is possible to provide an inexpensive printed wiring board that is less damaged when a press-fit connection terminal is inserted.

  In addition, it was possible to obtain a connection that can withstand harsh thermal shock environments without any special device for the press-fit terminal.

  Moreover, a printed wiring board suitable for press-fit connection could be manufactured without adopting a special process.

  In addition, although the material of the reinforcement layer was described as a metal core in the Example, it is not restricted to this. However, when the reinforcing layer is a metal core, it can also be used as a heat dissipation function or a ground circuit function. Moreover, although the rolled copper foil was used as the material of the metal core, other copper alloys, stainless steel, and aluminum alloys may be used.

  In addition, instead of using a metal core as the reinforcing layer as in the above-described embodiment and its modifications, the effect of the present invention can be produced even if a material having a low cost and strength equivalent to this is used as the reinforcing layer. Needless to say.

It is sectional drawing shown in the board | substrate thickness direction along the central axis of a through hole with the press-fit connection terminal which connects the printed wiring board concerning one Embodiment of this invention to this. It is process drawing of the manufacturing process of the printed wiring board shown in FIG. It is a figure corresponding to FIG. 1 which shows the 1st modification of the printed wiring board concerning one Embodiment of this invention shown in FIG. It is a figure corresponding to FIG. 1 which shows the 2nd modification of the printed wiring board concerning one Embodiment of this invention shown in FIG. It is a figure corresponding to FIG. 1 which shows the 3rd modification of the printed wiring board concerning one Embodiment of this invention shown in FIG. It is a table | surface which shows the evaluation test result of this invention. It is sectional drawing explaining the peeling which arose in the insulating layer. It is sectional drawing which showed the printed wiring board concerning one conventional embodiment in the wiring board thickness direction along the center axis line of a through hole. It is explanatory drawing which shows the malfunction which arose in the insulating layer of the conventional printed wiring board shown in FIG.

Explanation of symbols

1, 2, 3, 4, 5 Printed wiring board 111 Reinforcing layer 111a, 111b,... Pilot hole 112, 113 Conductor layer 121 (Upper side) Insulating layer 122 (Lower side) Insulating layer 130 (131, 132,... Through hole 130a (131a, 132a, ...) Through hole land 140 Metal plating 211 Reinforcing layer 211a, 211b, ... Pilot hole 212, 213 Outer layer conductor 221, 222 Insulating layer 230 (231, 232, ... Through hole 230a (231a, 232a,...) Through hole land 240 Metal plating 311 Reinforcing layer 312 Outer layer conductor 313, 314 Inner layer conductor 315 Outer layer conductor 321, 322, 323, 324 Insulating layer 330 (331, 332,. ..) Through hole 330a (331a, 332a,...) Through Luland 340 Metal plating 411 Reinforcement layer 430 (431, 432,...) Through hole 430a (431a, 432a,...) Through hole land 520 Insulating layer 520a, 520b Glass fiber 520c Insulating resin material 530 (531, 532,. ..) Through hole 530a (531a, 532a,...) Through hole land D Peeling (delamination)
T (T1, T2 ...) Press-fit connection terminal

Claims (3)

A printed wiring board having a plurality of through holes for inserting a plurality of press-fit connection terminals in a predetermined region, having a laminated insulating layer and a conductor layer,
A reinforcing layer having a thickness of 0.2 mm or more is interposed between the plurality of through holes inside the insulating layer, and at least a part of the reinforcing layer interposed between the through holes is at least one of the through holes. A printed wiring board characterized by being connected . 2. The printed wiring board according to claim 1, wherein at least a part of the conductor layer is made of an outer layer conductor, and a distance in a thickness direction from the outer layer conductor to the reinforcing layer is 0.3 mm or less. . The distance between the reinforcing layer and the through hole in the radial direction of the through hole is 0. The printed wiring board according to claim 1, wherein the printed wiring board is 5 mm or less.

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