JP5163547B2 - Card edge terminal manufacturing method for printed wiring board - Google Patents

Description

  The present invention relates to a method for producing a card edge terminal of a printed wiring board, and relates to a technique preferably applied to the production of a printed wiring board having a card edge connector that does not require a lead wire for connection to an electrode.

  Conventionally, in order to internally mount a printed circuit board in an electronic device, a card edge connector mounting substrate that is mounted by being directly inserted and fitted into a card edge connector provided in the device using the edge portion of the printed circuit board as a connection terminal portion has been used. ing. Each terminal printed on the connection terminal portion of the mounting substrate is often subjected to electrolytic gold plating in order to improve conductivity. In this electrolytic gold plating, an electrode connection lead wire is indispensable for electrically connecting the connection terminal portions.

  After the electrolytic gold plating is thus applied to the connection terminal portion and a predetermined circuit is formed, the printed circuit board is processed (cut) into a required size by a mechanical device such as a router to become a final substrate. Here, when the extension region of the connection terminal portion is cut out in this outer shape processing, the connection lead wire extending from the connection terminal portion is cut, and the connection lead wire is turned up and flashed. Separation may occur. Also, there is a risk of short-circuiting with the adjacent terminal due to turning or flashing of the connecting lead wire.

  On the other hand, as a technique for preventing the connection lead wire from being turned over or flashing, a method of arranging the connection lead wire in the inner layer is disclosed in Patent Document 1, for example. Further, for example, in Patent Document 2, as a technique for efficiently electroplating a metal exposed portion such as a terminal in a wiring board, all terminals of an internal net of the wiring board are temporarily short-circuited and connected to an external terminal, An electrolytic plating method is disclosed in which this external terminal is connected to an electrode to perform electroplating, and then a short circuit is released and a short circuit portion of each terminal is post-treated.

JP-A-9-162508 JP 59-165491 A

  Although the invention of Patent Document 2 can certainly plate each terminal of the internal net at once by simply connecting the electrode to the external terminal of the wiring board, it cannot cope with turning or flashing of the connecting lead wire. The invention of Patent Document 1 tries to prevent the connection lead wire from being turned over or flashed by arranging the connection lead wire inside the substrate. However, it takes a certain amount of steps to arrange the connection lead wire. Moreover, there is a concern about the generation of corrosion products on the exposed portions of the lead wires.

  Therefore, the present invention provides a method for manufacturing a card edge terminal of a printed wiring board, wherein the connection terminal portion is formed by electrolytic plating on the edge portion of the substrate without forming connection lead wires as power supply means for performing electrolytic plating. The purpose is to do.

  In order to achieve such an object, the card edge terminal manufacturing method for a printed wiring board according to the present invention uses a copper thin film formed on the entire surface of the printed wiring board as an electrode for power feeding, and electrolyzes a predetermined region on the printed wiring board. A terminal forming step of forming a terminal by performing gold plating; and a circuit forming step of forming a circuit wiring pattern on the printed wiring board after the terminal forming step and performing external processing.

  According to the present invention, in the method for manufacturing a card edge terminal of a printed wiring board, the connection terminal portion is formed by electrolytic plating on the edge portion of the substrate without forming a connection lead wire as a power supply means for performing electrolytic plating. It becomes possible to do.

It is the flowchart which showed the card edge terminal manufacturing method of the printed wiring board which concerns on this invention. It is the flowchart which showed the card edge terminal manufacturing method of the printed wiring board which concerns on this invention. It is the flowchart which showed the card edge terminal manufacturing method of the printed wiring board which concerns on this invention. It is the figure which showed the connecting terminal part formed with the card edge terminal manufacturing method of the printed wiring board concerning this invention. It is the figure which showed the connection terminal part formed with the card edge terminal manufacturing method of the conventional printed wiring board. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention. It is a figure for demonstrating the card edge terminal manufacturing method of the printed wiring board which concerns on embodiment of this invention.

  In this invention, as shown in FIG. 1, the card edge terminal manufacturing method of a printed wiring board has terminal formation process S10 and circuit formation process S20. The terminal forming step S10 is a step of forming a terminal by performing electrolytic gold plating on a predetermined region on the printed wiring board using a copper thin film formed on the entire surface of the printed wiring board as a power feeding electrode, as shown in FIG. Thus, it may have a conductive thin film forming step S11, a gold plating region forming step S12, and a gold plating step S13. The circuit forming step S20 is a step of forming a circuit wiring pattern on the printed wiring board after the terminal forming step S10 and performing outline processing. As shown in FIG. 3, the copper tin plating region forming step S21, the copper plating step You may have S22, tin plating process S23, copper thin film removal process S24, tin thin film removal process S25, and post-processing process S26.

  Conductive thin film forming step S11 is a first step in which a copper thin film is formed on the entire surface of the printed wiring board. In the gold plating region forming step S12, a photosensitive dry film is applied to the entire surface of the printed wiring board after the copper thin film forming step S11, and a region where the terminals are formed (terminal forming region) and a region used for power feeding (power feeding). In this step, the photosensitive dry film in the region is removed to secure a region for gold plating. The gold plating step S13 is a step of forming a terminal by energizing the power feeding region formed in the gold plating region forming step S12 to perform electrolytic gold plating on the terminal forming region.

  In the copper tin plating region forming step S21, a photosensitive dry film is applied to the entire surface of the printed wiring board after the terminal forming step S10, and a region where a circuit is formed (circuit forming region) and a region used for power feeding (power feeding). In this step, the photosensitive dry film in the region is removed to secure a region for copper plating or tin plating. The copper plating step S22 is a step of energizing the power feeding region formed in the copper tin plating region forming step S21 to perform copper plating on the circuit forming region. The tin plating step S23 is a step of energizing the power feeding region formed in the copper tin plating region forming step S21 and performing tin plating on the circuit forming region in which the copper thin film is formed in the copper plating step S22. The copper thin film removing step S24 is a step of removing the copper thin film remaining on the printed wiring board after the tin plating step S23. The tin thin film removing step S25 is a step of removing the tin thin film formed in the tin plating step S23 after the copper thin film removing step S24. The post-processing step S26 is a step in which a solder resist is applied to the printed wiring board after the tin thin film removing step S25, and external processing such as substrate cutting is performed.

  FIG. 4 is a diagram illustrating a connection terminal portion formed by a method for manufacturing a card edge terminal of a printed wiring board according to the present invention, and FIG. 5 is a connection formed by a method for manufacturing a card edge terminal of a conventional printed wiring board. It is the figure which showed the terminal part. As shown in FIG. 4, in the printed circuit board card edge terminal manufacturing method according to the present invention, the terminal 1 is formed on the board edge portion of the printed circuit board 2 without forming the electrode connecting lead 3 which is essential in the conventional method. Can be formed. In the present invention, before the printed wiring board is subjected to outer shape processing, the copper thin film is formed on the entire surface and is in a conductive state. There is no need to form a connection lead wire for performing connection, and there is no connection lead wire on the substrate after the connection terminal is formed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
First, while forming an inner layer pattern about shield board core 4-1, lamination is performed, such as producing shield board surface layer copper foil 4-2, and shield board 4 is manufactured (Drawing 6). This is a process corresponding to the copper thin film forming process S11 of FIG. Next, a through-hole pilot hole 5 is drilled in the shield plate 4 (FIG. 7).

  Then, a photosensitive dry film 6 is stretched on the surface of the shield plate 4 (FIG. 8), and after exposure, the dry film of the terminal portion 7 and the feeding portion 8 at the time of electrolytic gold plating is developed and removed with sodium carbonate or the like (FIG. 9). . This is a step corresponding to the gold plating region forming step S12 of FIG. Next, electricity is passed through the power feeding portion 8 to generate electrolytic gold plating 9 on the terminal portion 7 (FIG. 10). This is a step corresponding to the gold plating step S13 of FIG. Next, the dry film 6 is peeled off with sodium hydroxide or the like (FIG. 11).

  Subsequently, a photosensitive dry film 10 is stretched on the shield plate 4 on which the electrolytic gold plating 9 is formed (FIG. 12), and after the exposure, the photosensitive dry film of the circuit / through hole portion 11 and the feeding portion 8 is developed with sodium carbonate or the like. It is removed (FIG. 13). This is a step corresponding to the copper tin plating region forming step S21 of FIG.

  Next, electricity is passed through the power feeding portion 8 to form a copper plating 12 on the circuit / through hole portion 11 (FIG. 14). This is a process corresponding to the copper plating process S22 of FIG. Next, tin plating 13 is formed as an etching resist (FIG. 15). This is a step corresponding to the tin plating step S23 of FIG. Next, the photosensitive dry film 10 remaining on the shield plate 4 is peeled off with sodium hydroxide or the like (FIG. 16).

  Then, the copper portion exposed by the shield plate 4 is removed by etching with an etching solution that does not affect the electrolytic gold plating 9 and the tin plating 13 (FIG. 17). This is a process corresponding to the copper thin film removing process S24 of FIG. Next, the tin plating 13 is removed by etching with an etching solution that does not affect the electrolytic gold plating 9 (FIG. 18). This is a process corresponding to the copper thin film removing process S25 of FIG. Through the above steps, the edge terminal 1, the circuit 14, and the through hole 15 in which the electroplating 9 is formed without the electrode connecting lead wire can be obtained.

  Thereafter, a printed wiring board is completed by applying a solder resist, external processing, and the like. This is a step corresponding to the post-processing step S26 in FIG.

[Second Embodiment]
A manufacturing method using panel plating will be described as a second embodiment of the present invention. First, the shield plate 4 is manufactured by forming the inner layer pattern, generating the shield plate surface layer copper foil 4-2, and the like (FIG. 6). Then, through holes 5 for through holes are made in the shield plate 4 (FIG. 7). The process up to this point is the same as in the first embodiment.

  Next, copper plating 20 is performed on the shield plate 4 to form through holes 21 (FIG. 19). This is a process corresponding to the copper thin film forming process S11 of FIG. Then, a photosensitive dry film 22 is stretched on the surface of the shield plate 4 (FIG. 20), and after exposure, the dry film of the terminal portion 23 and the power feeding portion 24 during electrolytic gold plating is developed and removed with sodium carbonate or the like (FIG. 21). . This is a step corresponding to the gold plating region forming step S12 of FIG. Next, electricity is passed through the power supply portion 8 to generate electrolytic gold plating 25 on the terminal portion 23 (FIG. 22). This is a step corresponding to the gold plating step S13 of FIG. Next, the dry film 22 is peeled off with sodium hydroxide or the like (FIG. 23).

  Subsequently, a photosensitive dry film 26 is stretched on the surface of the shield plate 4 (FIG. 24), and the dry film other than the portion where conductors such as circuits and through-holes need to be left after exposure is developed and removed with sodium carbonate or the like (FIG. 24). 25). This is a step corresponding to the copper tin plating region forming step S21 of FIG. At this time, in order to prevent the overhang 27 (FIG. 28) of the electrolytic gold plating 25, the photosensitive dry film 26 is left in a wider range than the electrolytic gold plating 25.

  Next, the copper portion exposed by the shield plate 4 is removed by etching with an etching solution that does not affect the gold plating portion (FIG. 26). This is a process corresponding to the copper thin film removing process S24 of FIG. In the second embodiment, since copper plating is performed on the entire surface of the substrate in FIG. 19, there are no steps corresponding to the copper plating step S22, the tin plating step S23, and the tin thin film removing step S25 in FIG. Then, the photosensitive dry film 26 is peeled off with sodium hydroxide or the like (FIG. 27). Through the above steps, the edge terminal 1, the circuit 26, and the through hole 21 in which the electrolytic plating 25 is formed without the electrode connecting lead wire can be obtained.

  Thereafter, solder resist coating, outer shape processing, and the like are performed to complete the printed wiring board. This is the same as the first embodiment and corresponds to the post-processing step S26 in FIG.

  The above-described embodiment is a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiment alone, and various modifications are made without departing from the gist of the present invention. Implementation is possible.

DESCRIPTION OF SYMBOLS 1 Edge terminal 2 Printed circuit board 3 Electrode connection lead wire 4 Shield board 4-1 Shield board core 4-2 Shield board surface layer copper foil 5,21 Pilot hole for through-hole 6,10,22,26 Photosensitive dry film 7,23 Terminal portion 8,24 Power feeding portion 9,25 Electrolytic gold plating 11 Circuit / through hole portion 12 Copper plating 13 Tin plating 14 Circuit 15 Through hole 20 Copper plating 27 Overhang

Claims (5)

Using a copper thin film formed on the entire surface of the printed wiring board as a power supply electrode, a terminal forming step of forming a terminal by performing electrolytic gold plating on a predetermined region on the printed wiring board;
A circuit forming step of forming a wiring pattern of a circuit on the printed wiring board after the terminal forming step and performing external processing;
A card edge terminal manufacturing method for a printed wiring board, comprising: The terminal forming step includes
A copper thin film forming step for forming a copper thin film on the entire surface of the printed wiring board;
Forming a gold plating region for applying a photosensitive dry film to the entire surface of the printed wiring board after the copper thin film forming step and removing the photosensitive dry film in the terminal forming region where the terminals are formed and the power feeding region used for power feeding Process,
A gold plating step in which the power supply region formed in the gold plating region formation step is energized to perform electrolytic gold plating on the terminal formation region;
The card edge terminal manufacturing method of a printed wiring board according to claim 1, wherein: The circuit forming step includes
Forming a copper tin plating area for applying a photosensitive dry film to the entire surface of the printed wiring board after the terminal forming step and removing the photosensitive dry film in the circuit forming area where the circuit is formed and the power feeding area used for power feeding Process,
A copper plating step of conducting copper plating on the circuit forming region by energizing the power feeding region formed in the copper tin plating region forming step;
A tin plating step of energizing the power feeding region formed in the copper tin plating region forming step, and performing tin plating on the circuit forming region in which a copper thin film is formed after the copper plating step;
The card edge terminal manufacturing method of a printed wiring board according to claim 1 or 2, wherein The circuit forming step includes
A copper thin film removal step of removing the copper thin film formed on the printed wiring board after tin plating is applied on the circuit wiring pattern of the printed wiring board;
A tin thin film removing step for removing a tin thin film formed by tin plating after the copper thin film removing step;
The card edge terminal manufacturing method of a printed wiring board according to any one of claims 1 to 3, wherein:   In the circuit forming step, after the copper thin film formed on the printed wiring board and the tin thin film formed on the circuit wiring pattern of the substrate are removed, a solder resist is applied to the printed wiring board to form an outer shape. A method for manufacturing a card edge terminal of a printed wiring board according to any one of claims 1 to 4, further comprising a post-processing step.

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