JP2010118510A - Connection structure and connection method of board and lead line - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connection structure of a printed circuit board and a lead wire and its connection method capable of connecting the board and the lead wires with high reliability, downsizing connection portion, and sealing the board and the lead wires with resin with high reliability even if the lead wires are packed in a bundle using a jacket and the like. <P>SOLUTION: The connection structure includes: a printed circuit board 1 formed with a plurality of through-holes 3 and a plurality of lead wires 2 taken out to the side of the board 1 and packed in a bundle. In the connection structure of the board 1 and the lead wire 2, ends 5 of the plurality of lead wires 2 are inserted into the through-holes 3, and fixed with solder 6. The plurality of lead wires 2 include a lead wire 2 inserted into a through-hole 3 from the side of the front surface 8 of the board 1, and a lead wire 2 inserted into a through-hole 3 from the side of the rear surface 10 of the board 1. The plurality of the lead wires 2 and the board 1 are covered and sealed with resin. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a connection structure and a connection method when connecting a lead wire to a substrate.

  Conventionally, as a method of connecting multiple lead wires to a printed circuit board etc., connect the female connector terminal to the board side with solder etc., connect the connector terminal to the lead wire side by crimping, etc. There is a method of fitting and connecting. However, in recent years, the demand for downsizing of the connecting portion is severe, and the method of connecting a substrate and a plurality of lead wires via a connector terminal has a problem that it requires extra space for the connector terminal and cannot be downsized. As a method for solving such a problem, there is a method in which a plurality of lead wires are directly connected to a substrate with solder. For example, Patent Document 1 discloses a method of soldering a flat cable to a substrate surface. According to this connection method, the connection portion can be reduced in size, but there is a problem that the reliability with respect to the tensile stress and thermal stress of the cable portion is poor. Patent Document 2 describes a method of inserting a cable into a substrate through hole and soldering as a highly reliable connection. According to this connection method, the connection portion can be reduced in size without impairing the connection reliability.

JP-A-5-183264 JP 2002-299783 A JP 62-40944 A

  However, when a plurality of lead wires are bundled together with a jacket or the like for improved handling, since the connection method described in Patent Document 2 is connected to the substrate without a gap between the plurality of lead wires, When the substrate and the lead wire connected to the substrate are covered with a resin and sealed, there is a problem that the resin does not rotate around the cable and the sealing reliability is lowered. Covering the jacket part with resin increases the reliability but increases the size. Also, when the interval between the through holes is increased, the resin periphery is improved, but the size is increased.

  Therefore, the object of the present invention is to solve the above problems, connect the substrate and the lead wire with high reliability, reduce the size of the connecting portion, and even if the lead wire is bundled by a jacket or the like, the substrate It is another object of the present invention to provide a connection structure and a connection method between a substrate and a lead wire that can seal the lead wire with a resin with high reliability.

  In order to solve the above-described problems, the present invention includes a substrate on which a plurality of through holes are formed, and a plurality of lead wires that are taken out to the side of the substrate and grouped into a bundle, and the plurality of lead wires The lead is inserted into the through hole and fixed with solder, and the lead is connected to the lead through the plurality of lead wires inserted into the through hole from the surface side of the substrate. And the lead wires inserted into the through holes from the back side of the substrate, and the plurality of lead wires and the substrate are covered with a resin and sealed.

  By inserting a plurality of lead wires into the through holes from both the front and back surfaces of the substrate, the substrate becomes a spacer, and a gap is formed between the lead wires inserted on the front and back surfaces. For this reason, the resin rotates well around the lead wire, and the reliability of sealing with the resin increases. In addition, by inserting the lead wires from both sides of the substrate, the lead wires are arranged almost vertically (front and back) symmetrically with respect to the substrate axis, so that the lead wire is connected and the substrate sealed with resin is used as a jig When attaching to the etc., the directionality of attachment can be eliminated.

  The through holes may be formed in a row or in a row on the substrate, and the lead wires may be inserted into the through holes alternately from the front and back sides of the substrate in the order of the through holes. .

  The gap between the lead wires is further vacant, and the periphery of the resin is further improved.

  The resin may be a heat shrinkable tube.

  Since the symmetry with respect to the front and back directions of the substrate is good, a highly reliable connection structure can be obtained by resin sealing with a cylindrical heat-shrinkable tube.

  Also, a plurality of through holes are formed in the substrate, and the leading ends of the lead wires bundled in the through holes are inserted one by one and fixed with solder, and these lead wires are laterally moved from the substrate. In the lead wire connecting method, when the lead wires are inserted into the plurality of through holes, the lead wires are divided into two groups, and one group of lead wires is inserted into the through holes from the surface side of the substrate. The other group of lead wires are inserted into the through holes from the back side of the substrate and fixed with solder, and the substrate and the plurality of lead wires are covered with resin and sealed.

  According to the present invention, the substrate and the lead wire can be connected with high reliability, the connecting portion can be reduced in size, and the substrate and the lead wire can be connected with high reliability even if the lead wires are bundled in a jacket or the like. Can be sealed with resin.

  Preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a side view of a connecting portion between a substrate and a lead wire, and FIG. 2 is a plan view of FIG.

  As shown in FIGS. 1 and 2, when connecting the substrate 1 and a plurality of bundled lead wires 2, a plurality of through-holes 3 are formed on the substrate 1 so as to be arranged in a dust shape. In addition, the tip portions 5 of the lead wires 2 bundled in the jacket 4 are inserted one by one and fixed with the solder 6. Specifically, the bundle 7 of the lead wires 2 is arranged on the side of the substrate 1, the first group 9 extending the lead wires 2 toward the front surface 8 of the substrate 1, and the second group 11 extending toward the back surface 10 side. The lead wires 2 of the first group 9 are inserted into the through holes 3 from the front surface 8 side of the substrate 1 and soldered, and the lead wires 2 of the second group 11 are transferred from the back surface 10 side of the substrate 1 to the through holes 3. Insert and solder. At this time, the lead wires 2 of the first group 9 and the lead wires 2 of the second group 11 are alternately arranged in the order of the through holes 3. That is, the lead wires 2 are alternately inserted into the through holes 3 from the front surface 8 side and the back surface 10 side of the substrate 1 in the order of the through holes 3. Thereby, the lead wires 2 along the front surface 8 or the back surface 10 of the substrate 1 are evenly separated. The lead wire 2 is obtained by coating a core wire 12 made of a conductor with an outer skin 13 made of an insulator, and the tip portion 5 is in a state where the outer skin 13 is peeled in advance and the core wire 12 is exposed.

  Thereafter, as shown in FIG. 3, the substrate 1 and the plurality of lead wires 2 are covered and sealed with a heat shrinkable tube 14 which is a resin. The heat shrinkable tube 14 is made of a polyamide or polyester hot melt material. Specifically, the heat shrinkable tube 14 is formed of a two-layer shrinkable tube having a hard outer layer 15 and an inner layer 16 having good adhesiveness. A two-layer shrinkable tube cannot be coated well unless it is symmetrical with respect to the central axis, but the substrate 1 to be sealed and the plurality of lead wires 2 are almost vertically (front and back) symmetrical with respect to the substrate axis, so it is easy. Can be sealed with high reliability. The two-layer shrinkable tube is resistant to impact and thermal stress, has excellent sealing reliability, and shrinks only by applying heat for several seconds, so that the processing cost is low. Since the lead wires 2 along the front surface 8 or the back surface 10 of the substrate 1 are separated from each other, the heat-shrinkable tube 14 rotates well around the lead wire 2 and a highly reliable resin sealing can be performed.

  The sealing resin is not limited to the hot melt material. As the sealing resin, an epoxy-based, silicone-based, or urethane-based potting material may be used.

  The connection structure of the substrate 1 and the lead wire 2 formed in this way is the substrate 1 in which the plurality of through holes 3 are formed, and the plurality of lead wires 2 taken out to the side of the substrate 1 and collected in a bundle. The leading ends 5 of the plurality of lead wires 2 are inserted into the through holes 3 and fixed by the solder 6, and the plurality of lead wires 2 are formed through the through holes from the surface 8 side of the substrate 1. 3 and the lead wire 2 inserted into the through hole 3 from the back surface 10 side of the substrate 1, and the plurality of lead wires 2 and the substrate 1 are sealed with a heat shrinkable tube 14. It will be a thing.

  Thus, when the lead wires 2 are inserted into the plurality of through holes 3, the lead wires 2 are divided into two groups 9, 11, and the lead wires 2 of the first group 9 are connected to the through holes 3 from the surface 8 side of the substrate 1. The lead wire 2 of the second group 11 is inserted into the through hole 3 from the back surface 10 side of the substrate 1 and fixed with the solder 6, and the substrate 1 and the plurality of lead wires 2 are made of resin. Since it is covered and sealed, the substrate 1 and the lead wire 2 can be connected with high reliability, the connecting portion 17 can be reduced in size, and the lead wire 2 is bundled in a jacket 4 or the like. In addition, gaps can be formed between the plurality of lead wires 2, and the substrate 1 and the lead wires 2 can be sealed with resin with high reliability. In particular, since the resin turns well around the lead wire 2, the reliability of resin sealing is high.

  Further, through holes 3 are formed in a row or in a row in the substrate 1 and lead wires 2 are alternately inserted into the through holes 3 in the order of the through holes 3 from the front surface 8 side and the back surface 10 side. Therefore, the resin around the lead wire 2 is further improved, and the reliability of resin sealing can be further improved.

  Since the sealing resin is made of the heat-shrinkable tube 14, it can be easily sealed simply by applying heat for several seconds, and can be sealed with high reliability and low cost. Further, since the symmetry of the connecting structure of the substrate 1 and the lead wire 2 with respect to the front and back directions of the substrate 1 is good, the resin of the cylindrical heat-shrinkable tube 14 is evenly coated on the front and back of the substrate 1. For this reason, the reliability of sealing by the heat-shrinkable tube 14 can be increased, and thus a highly reliable connection structure can be obtained.

  In the above-described embodiment, the plurality of through holes 3 are formed in the form of being arranged in the substrate 1, but the present invention is not limited to this. For example, as shown in FIGS. 4 and 5, a plurality of through holes 3 may be formed in a line in the substrate 20. In this case as well, as described above, the bundle 7 of the lead wires 2 is arranged on the side of the substrate 20, the first group 9 extending the lead wires 2 to the front surface 21 side, and the second group extending to the back surface 22 side. The lead wires 2 of the first group 9 are inserted into the through holes 3 from the surface 21 side of the substrate 20 and soldered, and the lead wires 2 of the second group 11 are passed through from the back surface 22 side of the substrate 20. It is good to insert into the hole 3 and solder. The same effect as the above-described embodiment can be obtained. It is further preferable that the lead wires 2 are alternately inserted into the through holes 3 from the front surface 21 side and the back surface 22 side of the substrate 1 in the order of the through holes 3. The resin around the lead wire 2 can be further improved, and the reliability of resin sealing can be further improved.

  An example of the lead wire connection structure according to the present invention and a comparative example of the conventional lead wire connection structure will be described.

Example 1
The lead wire connection structure shown in FIGS. The substrate dimensions are length 18 mm x width 10 mm x thickness 1.6 mm. The substrate 1 was provided with six through holes 3 having a hole diameter of 1.2 mm in a dust-like arrangement as shown in FIG.

  6 lead wires 2 (outer diameter 1.4 mm, core wire: strand diameter 0.26 mm, strands of strands, strand material: copper, outer sheath, which are gathered on the substrate 1 with a jacket 4 (material: PVC) Three materials (vinyl chloride) were alternately inserted into the through holes 3 from the substrate surface 8 side and three from the substrate back surface 10 side. After that, the core wire 12 and the through hole 3 of the lead wire 2 are soldered with lead-free solder 6 (product name: M705-GRN360-K2-V (Sn96.5 / Ag3.0 / Cu0.5) made by Senju Metal). The heat shrinkable tube 14 is a two-layer shrinkable tube (manufactured by Tyco Electronics Amplifier Co., Ltd., ES2000-3) is placed on the connecting portion 17 between the substrate 1 and the lead wire 2 and heated at 160 ° C. for 1 minute to heat shrink and seal. Went. The two-layer shrinkable tube was covered up to six lead wires in front of the jacket 4.

  As a result, the inner layer 16 of the two-layer shrinkable tube was neatly filled around the lead wire outer skin 13, and the sealing performance was good. Further, the length (wrap amount) from the tip of the substrate 1 to the end of the two-layer shrinkable tube was as small as 5 mm, and the size could be reduced. Further, since the structure is almost vertical (front and back) symmetrical with respect to the substrate axis, it is necessary to care about the direction when the lead wire 2 is connected and the substrate 1 sealed with resin is attached to a jig or the like. Is gone.

(Example 2)
The lead wire connection structure shown in FIGS. The substrate dimensions are length 16 mm × width 13 mm × thickness 1.6 mm. The substrate 20 was provided with five through holes 3 having a hole diameter of 1.2 mm in the arrangement shown in FIG. 4 (arrangement that can be arranged in a line).

  Five lead wires 2 (outer diameter: 1.4 mm, core wire: strand diameter: 0.26 mm, strands: strand material: copper, outer sheath, which are gathered on the substrate 20 by a jacket 4 (material: PVC) Three materials (vinyl chloride) were alternately inserted into the through holes 3 from the substrate surface 21 side and from the substrate back surface 22 side. After that, solder the lead wire 2 core wire 12 and the through hole 3 with lead-free solder (Senju Metal, trade name M705-GRN360-K2-V (Sn96.5 / Ag3.0 / Cu0.5)) A two-layer shrinkable tube (manufactured by Tyco Electronics Amplifier Co., Ltd., ES2000-3) was placed on the connection portion 23 between the substrate 20 and the lead wire 2 and heated at 160 ° C. for 1 minute to heat shrink and seal. The two-layer shrinkable tube was covered up to five lead wires in front of the jacket 4.

  As a result, the inner layer 16 of the two-layer shrinkable tube was neatly filled around the lead wire outer skin 13, and the sealing performance was good. Further, the length (wrap amount) from the tip of the substrate 20 to the end of the two-layer shrinkable tube was as small as 5 mm, and the size could be reduced. In addition, since the structure is symmetric with respect to the substrate axis (front and back), when the lead wire 2 is connected and the substrate 20 sealed with resin is attached to a jig or the like, it is necessary to care about the directionality. lost.

(Comparative Example 1)
A conventional lead wire connection structure shown in FIGS. 6 and 7 was prototyped using the same substrate 1 as in Example 1, the same bundle 7 of the lead wires 2, the same solder 6, and the same two-layer shrinkable tube.

  The lead wire 2 is inserted into the through hole 3 of the substrate 1 from the substrate surface 8 side, the core wire 12 of the lead wire 2 and the through hole 3 are soldered with lead-free solder, and the two-layer shrinkable tube as the heat shrinkable tube 14 is formed on the substrate. 1 and the lead wire 2 were covered and heated at 160 ° C. for 1 minute to heat shrink and seal. The two-layer shrinkable tube was covered up to six lead wires in front of the jacket 4.

  As a result, since there is no space between the six lead wires 2, the inner layer 16 of the two-layer shrinkable tube is not filled around the lead wire sheath 13, and the sealing performance is insufficient. Further, since the lead wire 2 has a structure that is biased with respect to the substrate axis, the upper and lower sides (front and back) of the substrate 1 become asymmetrical, and the lead wire 2 is connected and the substrate 1 sealed with resin is used as a jig or the like. When installing, it has become necessary to care about the direction.

(Comparative Example 2)
The same substrate 20 as in the second embodiment, the same bundle 7 of the lead wires 2, the same solder 6, and the same two-layer shrinkable tube are used, and the five lead wires 2 are all inserted from the front surface side of the substrate 20 as in the second embodiment. A conventional lead wire connection structure with the same structure was prototyped.

  As a result, since the space between the five lead wires 2 is insufficient, the inner layer 16 of the two-layer shrinkable tube is not filled around the lead wire outer sheath 13, and the sealing performance is insufficient. Further, since the lead wire 2 has a structure that is biased with respect to the substrate axis, the top and bottom (front and back) of the substrate 20 is asymmetrical, and the lead wire 2 is connected and the substrate 20 sealed with resin is used as a jig or the like. When installing, it has become necessary to care about the direction.

It is a side view of the connection part of the board | substrate and lead wire which shows suitable embodiment of this invention. It is a top view of FIG. It is a side view of the connection part covered and sealed with the heat-shrinkable tube. It is a top view of the connection part of the board | substrate and lead wire which shows other embodiment. FIG. 5 is a side view of FIG. 4. It is a side view of the connection part of the conventional board | substrate and a lead wire. FIG. 7 is a plan view of FIG. 6.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Lead wire 3 Through-hole 5 Tip part 6 Solder 8 Front surface 9 1st group 10 Back surface 11 2nd group 14 Heat-shrinkable tube (resin)

Claims (6)

  A substrate having a plurality of through-holes and a plurality of lead wires taken out to the side of the substrate and assembled into a bundle, and the leading ends of the plurality of lead wires are inserted into the through-holes And a lead wire connecting structure fixed by solder together with the lead wires inserted into the through hole from the front surface side of the substrate and the through hole from the back surface side of the substrate. A structure for connecting a substrate and a lead wire, wherein the plurality of lead wires and the substrate are covered with a resin and sealed.   The through holes are formed in a row or in a row on the substrate, and the lead wires are inserted into the through holes alternately from the front surface side and the back surface side of the substrate in the order of the through holes. 1. Connection structure of substrate and lead wire according to 1.   The substrate and lead wire connection structure according to claim 1, wherein the resin is a heat shrinkable tube.   A substrate in which a plurality of through holes are formed in the substrate, and the leading ends of the lead wires bundled into the through holes are inserted one by one and fixed with solder, and the lead wires are taken out from the substrate to the side. In the lead wire connecting method, when inserting the lead wires into the plurality of through holes, the lead wires are divided into two groups, and one group of lead wires is inserted into the through holes from the surface side of the substrate. It is fixed with solder, the other group of lead wires are inserted into the through holes from the back side of the substrate and fixed with solder, and the substrate and the plurality of lead wires are covered with resin and sealed. To connect the board to the lead wire.   5. The substrate according to claim 4, wherein the through holes are formed in a row or in a row in the substrate, and the lead wires are alternately inserted into the through holes in the order of the through holes from the front surface side and the back surface side. And lead wire connection method.   The method for connecting a substrate and a lead wire according to claim 4 or 5, wherein the resin comprises a heat shrinkable tube.

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