JP5041893B2 - Board and connector terminals for preventing corrosion of current-carrying parts and connector dropout, and mounting method thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to mounting a connector by press-fitting it onto a board on which printed wiring frequently used for electronic components is mounted, and particularly when mounting a solderless connector called a “press-fit connector” on the board. The present invention relates to a substrate and a connector for preventing corrosion of the current-carrying portion and connector from falling off, and a mounting method thereof.

In recent years, the number of cases in which a solderless press-fit connector “press-fit connector” is employed in an assembly process of an apparatus using a substrate is increasing. While conventional connectors are connected by soldering when mounted on a substrate, the press-fit connector method can be mounted by a simple method by press-fitting, and the process can be simplified.
In addition, there is an active social movement to reduce harmful substances and environmentally hazardous substances, and manufacturing industries are required to make products that do not contain these substances regardless of the field. In particular, there is an urgent need to eliminate the use of solder lead, which is an electrical connection material. Furthermore, it is desired to separate and discard the substrate and the like, and the press-fit connector is a manufacturing method suitable for the times.
Since the press-fit connector can be mounted on the substrate simply by press-fitting, it is possible to eliminate the extra heating step for the surface mount component, which is a previous step, and contributes to lead-free. However, since a mechanical contact load is generated in the terminal and the through-hole to energize, the contact portion may deteriorate the energization performance due to corrosion due to vibration or oxidation.

  As shown in FIGS. 3 and 4, in the press-fit connector, a plurality of terminals 21 provided in the press-fit connector 20 are inserted into the through holes 10 formed in the substrate 8, and the wall plating layer 11 of the terminals 21 and the through holes 10 is inserted. Are energized by contacting each other. The inner diameter of the through hole 10 in FIG. 4 is about 0.6 mm, and the interval between the ribs 112 of the wall surface plating layer 11 is about 1 mm. The width of the printed wiring 12 is a narrow pitch of about 0.1 to 0.2 mm.

  The connection state between the terminal 21 of the conventional press-fit connector 20 and the through hole 10 is as shown in FIG. A through hole 22 is formed in the central portion of the portion where the terminal 21 is inserted, and the terminal 21 is widened to form a bulging portion 23.

The bulging portion 23 is formed wider than the diameter of the through hole 10 opened in the substrate 8. When the press-fit connector 20 is press-fitted, the bulging portion 23 is deformed in the direction of the through hole 22 and inserted into the through hole 10. Therefore, the wall surface plating layer 11 and the bulging portion 23 of the through hole 10 are in an interference fit state, and the bulging portion 23 and the wall surface plating layer 11 are in an interference fit state at the contact portion 25 so that they can be reliably contacted and energized.

  However, when inserting with an interference fit, the swelled portion 23 and the wall surface plating layer 11 may rub against each other to generate plating scraps. In the case of the conventional method, the metal scrap is scattered by cooling air or vibration. However, since the wiring 12 is formed with a narrow pitch pattern as shown in FIG. 4, if plating scraps adhere, it causes a short circuit failure.

In order to prevent such a short circuit failure, as proposed in Patent Document 1 (Japanese Patent Laid-Open No. 6-13735), it is proposed to laminate the both sides of the substrate 8 with a thin plastic film to prevent the scattering of the metal dust. There is something.
JP-A-6-13735

  As described above, when the terminal 21 of the press-fit connector 20 is press-fitted into the through hole 10, plating dust is generated and scattered, which may cause a short circuit failure. Furthermore, even if the wall plating layer 11 of the through hole 10 and the bulging portion 23 of the terminal 21 are energized by the contact portion 25 during assembly, they may oxidize and corrode over time, resulting in poor electrical conductivity. It was.

  In addition, when the substrate 8 on which the press-fit connector 20 is mounted is used in a place with a lot of vibration such as an automobile, the interference fit between the terminal 21 and the through hole 10 is loosened and may be slightly moved. As a result, the electrical conductivity may be further hindered by a synergistic effect with the oxidation of the contact portion 25.

If the bulging portion 23 is too wide at the time of press-fitting, the wall surface plating layer 11 of the through hole 10 may be mounted with the plating layer cracking. In this case, power is supplied at the time of mounting, but since the terminal 21 is not inserted in an interference fit state, there is a possibility that the power supply performance may be hindered as soon as slight movement is caused by slight vibration. In addition, the shaving pieces generated when the plating is cracked may cause a short circuit between the wiring patterns.

As described in Patent Document 1 described above, the method of laminating both surfaces of the substrate 8 with a thin plastic film can prevent the scattering of the plating dust, but the terminal 21 is inserted by breaking the laminated plastic film. Because of this method, it is impossible to deal with loosening of the contact portion 25 caused by plating cracking or vibration. Further, it is considered that it is not possible to cope with a failure in energization due to oxidation of the contact portion 25 that occurs due to contact with air.

Therefore, a method of mounting the connector on the substrate by inserting a terminal of a connector wider than the through-hole diameter into a through hole opened in the substrate, and applying a paste-like curable resin to the terminal; A press-fitting procedure for press-fitting the terminal coated with the paste-like curable resin into the through-hole with a set pressure, and a fixing procedure for fixing the terminal to the through-hole by curing the paste-like curable resin. Connector mounting method.
In addition, a connector that is inserted into a through-hole of a board and is mounted, and is wider than the through-hole and inserted by press-fitting into the through-hole, and the paste-like curability applied to the terminal The present invention provides a press-fit connector characterized by comprising a resin.

And, a method of mounting the connector on the substrate by inserting a connector terminal wider than the through-hole diameter into the through-hole opened in the substrate, and filling the through-hole with a paste-like curable resin A procedure, a press-fitting procedure for press-fitting the terminal into the through-hole filled with the paste-like curable resin at a set pressure, and fixing the connector mounted on the substrate by curing the paste-like curable resin A connector mounting method consisting of an adhering procedure.
And a board on which a terminal of the connector is inserted and mounted, the terminal being wide and press-fitted, and a through-hole opened in the board, and a paste-like curable resin filled in the through-hole The board | substrate for press-fit type connectors characterized by having been provided is provided.
The pasty curable resin is characterized by being cured by heat, characterized by being cured by UV light, and being cured by reacting with air.

In the present invention, as shown in FIG. 1, the paste-like curable resin 7 is applied to the terminals 21 of the press-fit connector 20 and inserted into the through-hole 10 or the paste-like curable resin 7 is inserted into the through-hole 10. Then, the terminal 21 is inserted to fill the through hole 10 with the paste curable resin. This prevents the terminal 21 and the wall surface plating layer 11 from coming into contact with air, thereby preventing corrosion due to oxidation of the contact portion 25 and preventing long-term conductivity from deteriorating.

In addition, the paste-like curable resin 7 is a thermosetting resin, so that the paste-like curable resin 7 is cured by applying heat to the substrate 8 on which the press-fit connector 20 is mounted. By preventing the eleven contact portions 25 from moving, it is intended to prevent deterioration of the conductivity due to fine movement caused by vibration.

Further, by using a conductive paste-like curable resin 7, even if the contact portion 25 is deteriorated and the conductivity is deteriorated, the cured paste-like curable resin 7 is energized by energization. It is possible to maintain the current-carrying performance for a long time more reliably.

As shown in FIGS. 3 and 4, the press-fit connector 20 is attached by being pressed from above so that the terminal 21 is inserted into the through hole 10 of the substrate 8. At that time, the press-fit connector 20 is press-fitted with an upper jig and a lower jig that are specially made. For example, Japanese Patent Application No. 20077-142697 and Japanese Patent Application No. 2007-159971 are used as the press-fitting device.

  FIG. 5 shows a cross section of the through hole 10 opened in the substrate 8. A wall surface plating layer 11 is provided on the inner peripheral surface of the through hole 10, and the upper and lower hole surfaces of the substrate 8 are integrated with the flange 112. A wire 12 is connected to the collar 112 and is energized.

  The terminals 21 of the press-fit connector 20 are energized by contacting the wall plating layer 11. For this purpose, the bulging portion 23 of the terminal 21 is made slightly wider than the inner diameter of the through hole 10, and the through-hole 22 is opened in the terminal 21 so that the bulging portion 23 is compressed and tightly fitted when press-fitted. ing.

  The principle of connection of the press-fit connector 20 will be described with reference to FIG. As shown in FIGS. 2 and 1, the inner diameter c of the through hole 10 is slightly smaller than the width e of the bulging portion 23 of the terminal 21. Further, a through hole 22 is formed in the central portion of the terminal 21 so that the width e of the bulging portion 23 can be reduced to the width c by press-fitting. The terminal 21 is inserted into the through hole 10 by pressure P in an interference fit.

  As shown in FIGS. 2 and 2, when the terminal 21 is press-fitted into the through hole 10, the bulging portion 23 is inserted into the through hole 10 while being compressed and deformed in the direction of arrow G. At this time, the bulging portion 23 and the wall surface plating layer 11 come into contact with each other, and in some cases, metal scraps scraped by the bulging portion 23 and the wall surface plating layer 11 may be generated.

  In general, tin (Sn) or silver (Ag) plating is applied to the surface of the terminal 21 and the wall plating layer 11 to improve the electrical conductivity. As described above, the press-fitting of (2) in FIG. It is often peeled off to generate gold dust.

  When the terminal 21 is inserted as shown in (3) of FIG. 2, the bulging portion 23 is in a contracted state, so that a contact load H is generated in the direction of the arrow H, and the contact portion 25 is constantly compressed. Energized state is secured. Based on the above principle, the terminal 21 of the press-fit connector 20 is inserted into the through-hole 10 and becomes energized.

  Next, the gist of the present invention will be described with reference to FIG. FIG. 1 (1) shows a state in which the paste-like curable resin 7 is applied to the bulging portion 23 and the through hole 22 of the terminal 21. Since the paste-like curable resin 7 is sticky and has a high surface tension, it is kept in the applied state and does not flow down. Application can be easily performed by using a spraying device, an adhesive application device (bonder), or the like. Further, it can be applied by immersing the terminal 21 portion of the press-fit connector 20 in the paste-like curable resin 7.

  When the terminal 21 is inserted into the through hole 10, the state shown in FIG. As described above, the paste-like curable resin 7 does not flow down due to adhesiveness and surface tension, and is in the state of the paste-like curable resin 7 in the hatched portion in FIG. The contact portion 25 between the bulging portion 23 and the wall surface plating layer 11 is fitted in an interference-fitted state while generating the plating dust, so that it can be directly contacted and energized even if partially.

  When the terminal 21 is inserted into the through-hole 10, the paste-like curable resin 7 is excluded from the contact portion 25 and filled in the non-contact portion. The metal scrap generated at the time of insertion is prevented from being mixed into the paste-like curable resin 7 and scattered.

FIG. 1 (2) shows a state in which the through-hole 10 is filled with the paste-like curable resin 7 in advance. As for the filling method, it is only necessary to inject with a syringe or the like, and since a device for automatically creating a through hole at a predetermined position and a device for applying an adhesive at a predetermined position are commercially available, it is easy. The through-hole 10 can be filled with the paste-like curable resin 7.
As in the case of (1) in FIG. 1, when the terminal 21 is inserted into the through hole 10, the state of (3) in FIG. The effect is the same as described above, and it is possible to prevent the metal dust from being mixed into the paste-like curable resin 7 and scattered.

  The substrate 8 in which the terminal 21 is inserted into the through hole 10 and is in the state of (3) in FIG. 1 is heated in a furnace or the like and heated to about 150 ° C., and the paste-like curable resin 7 is cured. As the paste-like curable resin 7, a thermosetting resin is used and is cured at around 150 ° C. Incidentally, heat resistance tests at around 150 ° C have been performed on substrates used in automobiles.

  If the paste-like curable resin 7 is cured by heating and the paste-like curable resin 7 is hardened as shown in FIG. 1 (3), the terminal 21 is fixed while being fitted in the through hole 10. As a result, the terminal 21 comes off due to vibrations or is finely moved, and the conductivity of the contact portion 25 with the wall surface plating layer 11 is not deteriorated, and long-term safety is ensured.

  In addition, since the through hole 10 and the terminal 21 are covered with the paste-like curable resin 7 and sealed, it is possible to prevent the contact portion 25 from being oxidized and corroded without being exposed to air, thereby preventing deterioration of conductivity. It is possible to ensure stable energization performance for a period.

  In this embodiment, the paste-like curable resin 7 is a thermosetting resin. However, a UV curable resin may be used and cured by ultraviolet irradiation (UV light). For example, when a component having low heat resistance is used for the substrate 8, it is desirable to use a UV curable paste-like curable resin 7 to avoid a thermal effect.

  Furthermore, the paste-like curable resin 7 may be non-conductive or conductive. In the case of the non-conductive paste-like curable resin 7, the contact portion 25 is sealed and fixed by thermosetting, thereby preventing deterioration of the conductivity due to fine movement of the terminal 21 or corrosion due to oxidation.

  In addition, even if a large amount of non-conductive paste-like curable resin 7 is applied and protrudes from the ridge 112 of the wall surface plating layer 11 and flows out into contact with the ridge 112 of other through holes 10, a short circuit failure occurs. There is nothing to do. In some cases, the press-fit connector 20 can be reliably fixed to the substrate 8 without any problem even if it is applied between the press-fit connector 20 and the substrate 8 and bonded together.

  Next, it will be explained that the paste-like curable resin 7 may be a conductive material. In recent years, thermosetting conductive paste-like curable resins containing silver (Ag) and the like have been put on the market as solder lead-free has progressed.

  Of course, when the conductive paste-like curable resin 7 is cured as shown in FIGS. 1 and 3, it is possible to prevent the deterioration of the conductivity due to the fine movement or oxidation of the contact portion 25 as described above. However, since the paste-like curable resin 7 is conductive, the entire inside of the through hole 10 can be energized, and reliable energization is ensured.

  However, as described for the non-conductive paste-like curable resin, when the conductive paste-like curable resin 7 comes into contact with the flange 112 of the other through-hole 10, a short-circuit failure occurs, so the paste-like curable resin It is necessary to accurately determine the amount of the resin 7 to be applied and the position to be applied by an experiment or the like. However, when the conductive paste-like curable resin 7 is applied and cured as shown in (3) of FIG. 1, reliable and stable energization is possible and the effect is remarkable.

As described above, the present invention applies the paste-like curable resin 7 to the terminal 21 regardless of conductivity or non-conductivity or fills the through hole 10 and then inserts the terminal 21 into the through hole 10. It is what I did. The paste-like curable resin 7 is applied to the terminal 21 using both (1) and (2) of FIG. 1 and simultaneously filled in the through hole 10, and then the terminal 21 is inserted into the through hole 10. Can be assembled.

Since the paste-like curable resin 7 has high surface tension and adhesiveness, it is applied to the terminal 21 without flowing down until it is thermally cured, and is filled in the through hole 10. Therefore, when both are assembled, the paste-like curable resin 7 is filled in the through hole 10 as shown in FIG. Then, the contact portion is protected by curing the paste-like curable resin 7 in the state of (3) in FIG.

With the configuration and method as described above, the metal scrap generated at the time of assembly is mixed into the paste-like curable resin 7, so that it does not scatter and does not cause a short circuit failure. In addition, since the paste-like curable resin 7 covers and seals the entire through-hole 10, it is possible to prevent deterioration of conductivity due to fine movement of the contact portion 25 or corrosion due to oxidation.

In addition, since the conductive property can be improved by using the conductive paste-like curable resin 7, the bulging portion e is larger than the inner diameter c of the through hole 10 and the wall plating layer 11 is not cracked. Even if it is generated, it is possible to prevent the plating cracks from expanding due to the paste-like curable resin 7 being cured. In particular, it is often impossible to judge a crack that has occurred during assembling by means of an electrical inspection alone. Even if a plating crack occurs by using the conductive paste-like curable resin 7, it is possible to prevent the crack from expanding more than the current state, so that the energization performance can be ensured for a long time.
In addition, the paste-like curable resin 7 regardless of conductivity or non-conductivity can be prevented from decreasing the contact load H caused by plating cracking because the paste-like curable resin 7 is in close contact with the through hole 10 and the terminal 11 and cured.

Similarly, even if the bulging portion e is smaller than the inner diameter c of the through hole 10 and the terminal 21 has a minute contact portion, the conductive paste-like curable resin 7 can be used to reliably energize. it can. Further, when the paste-like curable resin 7 contains an oil component, the insertion of the terminal 11 into the through hole 10 becomes smooth, the set pressure can be reduced, and the generation of plating dust can be prevented.

The present invention can be applied not only to the mounting of the press-fit connector 20 but also to various terminals on the substrate.

It is detail drawing when the terminal and through-hole which apply | coated paste-form curable resin are assembled. It is detail drawing which shows the connection principle when inserting a terminal in a through hole. It is a schematic diagram when mounting a press-fit connector on a substrate. It is a detail drawing of a through hole and wiring of a substrate. It is detail drawing when a conventional terminal and a through hole are assembled.

Explanation of symbols

7
Paste curable resin
8
substrate
10 Through hole
11 Wall plating layer
12 Wiring
20 Press-fit connector
21 terminals
22 Through hole
23 bulge
25 Contact area
112 鍔
c Inside diameter of through hole
e Width of bulge
G Compression load
H Contact load
P pressure

Claims (2)

Than the through hole diameter that has been subjected to said wall surface plated layer in the through-hole that has been subjected to wall plating layer drilled in the substrate by inserting the terminal of the wide connector to a method of mounting the connector to said substrate,
An application procedure for applying a paste-like curable resin to the terminal;
A press-fitting procedure for press-fitting the terminal coated with the paste-like curable resin into a through-hole provided with the wall plating layer at a set pressure;
It comprises an adhering procedure for adhering the terminal to the through-hole provided with the wall surface plating layer by curing the paste-like curable resin,
In the press-fitting procedure, the bulging portion provided in the terminal by the through-hole provided in the central portion of the terminal contracts the terminal and the wall surface plating when the terminal is compressed through the through-hole provided with the wall surface plating layer. The layered through hole is inserted with an interference fit, and the paste-like cured resin is excluded from the contact portion of the through hole with the terminal and the wall plating layer so that the non-contact portion is filled. West,
A connector characterized by preventing scattering of plating scraps and expansion of plating cracks caused by contact between the bulging portion provided in the terminal and the wall plating layer of the through-hole provided with the wall plating layer. Mounting method. Than the through hole diameter that has been subjected to said wall surface plated layer in the through-hole that has been subjected to wall plating layer drilled in the substrate by inserting the terminal of the wide connector to a method of mounting the connector to said substrate,
A filling procedure for filling a paste-like curable resin into the through-hole provided with the wall surface plating layer ;
A press-fitting procedure for press-fitting the terminal with a set pressure into a through-hole provided with the wall plating layer filled with the paste-like curable resin;
It comprises an adhering procedure for adhering the connector mounted on the substrate by curing the paste-like curable resin,
In the press-fitting procedure, the bulging portion provided in the terminal by the through-hole provided in the central portion of the terminal contracts the terminal and the wall surface plating when the terminal is compressed through the through-hole provided with the wall surface plating layer. The layered through hole is inserted with an interference fit, and the paste-like cured resin is excluded from the contact portion of the through hole with the terminal and the wall plating layer so that the non-contact portion is filled. West,
A connector characterized by preventing scattering of plating scraps and expansion of plating cracks caused by contact between the bulging portion provided in the terminal and the wall plating layer of the through-hole provided with the wall plating layer. Mounting method.