JP2011151201A - Method of manufacturing electronic circuit unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an electronic circuit unit that suppresses a range of solder paste to be applied to a periphery of a through hole on a substrate during reflow soldering. <P>SOLUTION: The method of manufacturing the electronic circuit unit includes: applying solder paste p1 to the through hole 55 and its periphery on a first mounting surface 52 of the substrate 50; melting the paste p1 by heating to make the paste flow in the through hole as solder (h); applying paste p2 to the through hole 55 and its periphery on a second mounting surface 52; arranging a connector 10 so that a tip of a connector terminal 12 is mounted on solder (h) solidified in the through hole 55; and in this state, melting the solidified solder (h) by heating to sink the tip of the connector terminal 12 mounted on the melted solidified solder (h), in the through hole 55, and making the paste p2 applied to the second mounting surface 52, flow in the through hole 55 as the solder (h). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an electronic circuit unit in which a plurality of mounting parts including connectors are mounted on both sides of a printed circuit board.

  Conventionally, as a method of manufacturing an electronic circuit unit by mounting a connector on a printed circuit board provided with a through hole (hereinafter, also simply referred to as “printed circuit board manufacturing method”), the reflow solder described in Patent Document 1 is used. A method of manufacturing an electronic circuit unit by attaching is known.

  In this method of manufacturing an electronic circuit unit, a printed circuit board 101 having a through hole shown in FIG. 4A is prepared. As shown in FIG. 4B, the through hole 102 of the printed circuit board 101 and its surroundings are prepared. The solder paste P is applied to Then, as shown in FIG. 4C, the connector 106 is arranged on the printed circuit board 101 so that the connector terminal 104 passes through the through hole 102 from the solder paste P application surface side of the printed circuit board 101. Thereafter, the printed circuit board 101 in which the connector 106 is disposed is heated in a reflow furnace. The solder paste P is melted by this heating, and the through hole and the solder applied to the periphery thereof flow into the through hole 102 due to the surface tension, and as shown in FIG. The space between the inner peripheral surface of the hole 102 is filled with the solder H, whereby the connector terminal 104 and the through hole 102 are electrically connected using the solder H as a medium. Thus, the electronic circuit unit 100 is manufactured by soldering the connector 106 to the printed circuit board 101.

JP 7-263857 A

  In the method of manufacturing an electronic circuit unit by reflow soldering as described above, between the outer peripheral surface of the connector terminal 104 and the inner peripheral surface of the through hole 102, that is, in the through hole 102 in a state where the connector terminal 104 is inserted. An amount of solder paste P that can be filled with solder needs to be applied to the through hole 102 of the printed circuit board 101 and the periphery thereof before the reflow process (see FIG. 4C). In this reflow soldering, it is necessary to fill the space between the outer peripheral surface of the connector terminal 104 and the inner peripheral surface of the through hole 102 with solder, so that a lot of solder H is required as compared with the case where the surface mount connector is soldered to the printed circuit board. Therefore, it is necessary to apply a solder paste to a wide area around the through hole 102 on the printed circuit board 101.

  Therefore, in the manufacturing method of the electronic circuit unit described above, in order to avoid the solder paste applied around the through hole 102 on the printed circuit board 101 when mounting other mounting components besides the connector 106 on the printed circuit board 101. It was difficult to reduce the size of the electronic circuit knit 100 because other mounting components could not be arranged in a wide range around the through hole 102.

  Therefore, in view of the above problems, the present invention provides an electronic circuit unit manufacturing method capable of suppressing the range of solder paste applied around a through hole on a printed circuit board during reflow soldering. Let it be an issue.

  Therefore, in order to solve the above problems, the present invention has a printed circuit board having a through hole, and a plurality of mounting parts mounted on the printed circuit board. The plurality of mounting parts include connector terminals, A connector housing that has a bottom surface that is in contact with a mounting surface of the printed circuit board when mounted on the printed circuit board, and holds the connector terminal such that a tip portion protrudes from the bottom surface toward the mounting surface side; A first printing step of applying a solder paste to the through hole and its periphery on a first mounting surface, which is one mounting surface of the printed circuit board, including a connector comprising: A solder paste for mounting the other mounting component is applied to the mounting position of the mounting component other than the connector on the first mounting surface. A second printing step, a first arrangement step of arranging the other mounting component at the planned mounting position on the first mounting surface to which the solder paste is applied in the second printing step, and a solder paste in the first printing step. And the solder paste applied in the first printing step flows into the through hole as solder by heating the printed circuit board in a state where the other mounting components are arranged in the first arranging step. And a first reflow process for fixing the other mounting component to the first mounting surface with the solder paste applied in the second printing process, and the first mounting surface on the printed circuit board after the first reflow process. A third printing step of applying a solder paste to the through hole and its periphery on the second mounting surface facing the opposite side, and the third printing process On the second mounting surface of the printed circuit board with the second mounting surface coated with the solder paste facing up, it is cooled and solidified in the through-hole that has flowed in by heating in the first reflow process. A second arrangement step of arranging the connector so that the tip of the connector terminal is placed on the solder; and heating the printed circuit board in a state where the connector is arranged on the second mounting surface in the second arrangement step. As a result, the solidified solder is melted and the tip of the connector terminal placed thereon is lowered in the through hole and the solder paste applied in the third printing step is used as solder in the through hole. And a second reflow process to be introduced.

  According to such a configuration, a plurality of mounting components including connectors are soldered to both surfaces (first mounting surface and second mounting surface) of the printed board. At this time, in order to solder the connector, an amount of solder paste necessary to fill the space between the outer peripheral surface of the connector terminal and the inner peripheral surface of the through hole with the solder is applied separately to the first mounting surface and the second mounting surface. By doing so, it is possible to narrow the application range of the solder paste on each mounting surface compared to the case where the solder paste is applied only to one mounting surface.

  Specifically, on the first mounting surface, a solder paste is applied to the through hole and the periphery thereof, and a solder paste for mounting another mounting component is applied to the predetermined mounting position. Place mounting components. Then, by heating this printed circuit board in the first reflow step, other mounting components are soldered to the first mounting surface, while the through holes and the solder paste applied to the periphery thereof are melted to form liquid solder. The solder flows into the through hole due to the surface tension. Next, solder paste is applied to the through hole on the second mounting surface and the periphery thereof, and the second mounting surface is directed upward, and then flows into the through hole in the first reflow process. The connector is arranged so that the tip of the connector terminal is placed on the solder that has been cooled and solidified. In this state, by heating in the second reflow process, the solder solidified in the through hole is melted, and the tip of the connector terminal descends in the through hole. In the third printing process, the through hole in the second mounting surface is lowered. In addition, the solder paste applied to the periphery thereof is melted to form a liquid solder, and the solder flows into the through hole by the surface tension. As described above, the solder paste applied to the through holes and the periphery thereof on both the first mounting surface and the second mounting surface can contribute to the soldering of the connector. As a result, it is possible to mount other mounting components near the through hole as compared with the manufacturing method of the electronic circuit unit in which the solder paste is applied only to one surface of the printed circuit board.

  In the method of manufacturing an electronic circuit unit according to the present invention, the connector includes a fixing member that protrudes from the bottom surface in the same direction as the protruding direction of the tip of the connector terminal that protrudes from the bottom surface of the connector housing. When the fixing member is arranged on the second mounting surface in the second arranging step, the fixing member cooperates with the connector terminal so that the bottom surface faces the second mounting surface and the second mounting surface. The connector housing is supported in a floating state, and the printed circuit board has the fixing member at a position corresponding to the fixing member when the connector is arranged on the second mounting surface in the second arrangement step. A fixing through hole having an inner diameter that can be passed, and in the first printing step, the fixing through hole on the first mounting surface and the periphery thereof are also soldered. In the first reflow step, the through hole and the solder paste applied to the periphery thereof flow into the through hole as solder on the first mounting surface by the heating in the first reflow step. In addition, the solder paste applied to the fixing through-hole and the periphery thereof flows into the fixing through-hole as solder, and in the third printing step, the fixing through-hole and the periphery thereof on the second mounting surface In the second arrangement step, the tip of the connector terminal is placed on the solder that is cooled and solidified in the through-hole that has flowed in due to the heating in the first reflow step, and the first reflow is applied. The fixing part on the solder solidified by cooling in the fixing through-hole that has flowed in due to heating in the process In the second reflow step, the solder solidified in the through-hole is melted by heating, and the tip of the connector terminal placed on the connector is placed in the through-hole. And the solder paste applied in the third printing step is caused to flow into the through hole as solder, and the solidified solder in the fixing through hole is melted and placed on the solder paste. It is preferable that the tip of the fixing member is lowered in the fixing through hole and the solder paste applied in the third printing process is caused to flow into the fixing through hole as solder.

  According to such a configuration, in addition to the connector terminal, the fixing member having a tip protruding from the bottom surface of the connector housing to the printed circuit board side is provided, so that the connector can be used without using a support member or a support means in the second arrangement step. By using the terminals and the fixing members as legs, the connector can be stably made to stand on the printed circuit board (that is, disposed).

  In addition, by allowing the connector terminal and the fixing member tip to be placed on the portion, the connector terminal and the fixing member tip are applied with the weight of the connector from the tip of the connector terminal and the fixing member. . Thereby, only by heating in the second reflow step, the connector housing that has floated from the second mounting surface is lowered until it comes into contact with the second mounting surface. That is, by the heating in the second reflow process, the solder solidified in the through hole and the fixing through hole is melted, respectively, and the tip of the connector terminal and the tip of the fixing member placed thereon are in the through hole and Each of the connector housings descends in the fixing through hole, and the connector housing also descends toward the second mounting surface along with the descending.

  Moreover, in the manufacturing method of the electronic circuit unit of this invention, a work process can be decreased by performing the said 1st printing process and the said 2nd printing process simultaneously.

  As described above, according to the present invention, it is possible to provide a method of manufacturing an electronic circuit unit that can suppress the range of solder paste applied around the through hole on the printed circuit board during reflow soldering.

It is a figure which shows the connector which concerns on this embodiment, Comprising: (a) is a front view, (b) is a side view. It is a figure explaining the manufacturing method of the electronic circuit unit which concerns on the same embodiment, Comprising: (A) shows the printed circuit board before a solder paste is apply | coated, (B) is a solder paste being apply | coated to the 1st mounting surface. (C) shows a state in which other mounting components other than the connector are arranged on the first mounting surface to which the solder paste is applied. It is a figure explaining the manufacturing method of the electronic circuit unit which concerns on the embodiment, Comprising: (A) shows the state by which the solder paste was apply | coated to the 2nd mounting surface after the 1st reflow process, (B) is soldering A state where the connector is arranged on the second mounting surface where the paste is applied is shown, and (C) shows a state of the electronic circuit unit after the second reflow process. It is a figure explaining the mounting method of the connector on the conventional printed circuit board, Comprising: (A) shows the printed circuit board before a solder paste is apply | coated, (B) shows the state by which the solder paste was apply | coated to the mounting surface (C) shows the state where the connector is arranged on the mounting surface to which the solder paste is applied, and (D) shows the state of the electronic circuit unit after the reflow process.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In this embodiment, an electronic circuit unit is manufactured by mounting a plurality of electronic components (mounting components) including connectors on both surfaces (both mounting surfaces) of a printed circuit board. Specifically, as shown in FIGS. 1 to 3C, an electronic component (other electronic component) 30 other than the connector 10 is mounted on one surface (first mounting surface) 51 of the printed circuit board 50. Then, the electronic circuit unit 1 is manufactured by mounting the connector 10 on the second mounting surface 52 facing the side opposite to the first mounting surface 51.

  Hereinafter, although described in detail, first, the connector 10 mounted on the printed circuit board 50 will be described.

  The connector 10 has a plurality of connector terminals (hereinafter also simply referred to as “terminals”) 12, an insulating housing (hereinafter also simply referred to as “housing”) 14 that holds the plurality of terminals 12, and the housing 14 is printed. And a fixing member 20 for fixing to the substrate 50 (see FIG. 2A).

  The housing 14 is integrally formed of an insulating material such as synthetic resin, and has a substantially rectangular parallelepiped shape extending in the left-right direction (the left-right direction in FIG. 1A). When mounted on the printed circuit board 50, the housing 14 is perpendicular to the printed circuit board 50 (see FIG. 3C) and extends in the left-right direction. 1 (b) right side), a top wall 17 extending forward from the upper end of the back wall 15, and side walls 18 respectively extending forward from both side ends of the back wall 15. And when mounting on the printed circuit board 50, it mounts with the attitude | position which the bottom wall 16 and the mounting surface 52 (refer FIG.3 (c)) of the printed circuit board 50 face.

  Support portions 19 are respectively formed on the side wall surfaces 18 and 18 so as to protrude from the lower side toward the outside (in the left-right direction in FIG. 1A). A fixing member 20 that protrudes downward (downward in FIG. 1A) from the support portion 19 is provided on the lower end surface of the support portion 19 (the bottom surface 16a of the housing 14).

  The terminal 12 is formed by bending a metal bar-shaped member, and is held in the housing 14 (specifically, the back wall 15 of the housing 14) while the housing 14 is in the left-right direction (terminal arrangement direction). Are arranged along.

  Each terminal 12 is held by the housing 14 (back wall 15) at a portion passing through the back wall 15 of the housing 14, that is, a terminal holding portion. The front side of the back wall 15 of the terminal 12 protrudes from the back wall 15 into a fitting space surrounded by the bottom wall, the top wall, and the pair of side walls 18 and 18. The mating connector is inserted into the fitting space, and the protruding terminal 12 and the female terminal of the mating connector are fitted by this insertion. On the other hand, the rear side of the back wall 15 of the terminal 12 protrudes in the direction orthogonal to the back wall 15 from the back wall 15 to the back side, and then the direction is changed by 90 ° to the bottom wall 16 side along the back wall 15. Head over. The terminal extending along the back wall 15 extends to a position where the tip (mounting end) 12 a protrudes downward from the bottom surface of the bottom wall 16 in front view, that is, the bottom surface of the housing 14. This downward projecting portion (mounting end) 12a is inserted into the through hole 55 (see FIG. 3C) of the printed circuit board 50 and soldered to fix the terminal 12 to the through hole 55. And electrically connected.

  The fixing member 20 protrudes from the bottom surface 16a of the housing 14 in the same direction as the front end of the terminal 12 protruding downward from the bottom surface 16a of the housing 14. In this embodiment, the member extends straight from the lower surface of the support portion 19 downward. In the fixing member 20, the length dimension of the portion extending downward from the bottom surface 16 a of the housing 14 is the same as the length dimension of the portion of the terminal 12 protruding downward from the bottom surface 16 a of the housing 14. It is almost the same. By setting the fixing member 20 to such a length, when the connector 10 is placed on the horizontal surface with the terminals 12 and the tips of the fixing member 20 facing downward, the fixing member 20 and the terminal 12 are placed. And the housing 14 can be supported with the bottom surface 16a facing the horizontal plane and floating from the horizontal plane. That is, the connector 10 can be self-supported on the horizontal plane with the terminal 12 and the fixing member 20 as legs (see FIG. 3B).

  The connector 10 configured as described above is mounted on the following printed circuit board 50 when the electronic circuit unit 1 is manufactured.

  The printed circuit board 50 is a circuit board on which a circuit or the like is printed. The printed board 50 is provided with a through hole 55 at a position corresponding to the mounting end 12a of each terminal 12 of the connector 10 at a portion where the connector 10 is mounted, and is fixed at a position corresponding to the fixing member 20. A through hole 56 is provided. The fixing through hole 56 is a hole in the thickness direction of the printed circuit board 50 and has an inner diameter through which the fixing member 20 of the connector 10 can be inserted in the axial direction.

  Next, a process of manufacturing the electronic circuit unit 1 by mounting a plurality of electronic components (mounting components) 30 including the connector 10 on the printed circuit board 50 by reflow processing will be described with reference to FIGS. 2 (A) to 3 (C). However, it will be explained.

<Printing process of solder paste p1 on the first mounting surface 51>
First, as shown in FIG. 2A, a printed circuit board 50 having a through hole 55 and a fixing through hole 56 is prepared, and conveyed to the printing position of the solder paste p with the first mounting surface 51 facing upward. Is done.

  When the printed board 50 is conveyed to the printing position, the solder paste p1 is printed (applied) on a predetermined portion of the first mounting surface 51 of the printed board 50. Specifically, a mask (not shown) with a hole in a predetermined portion is overlaid on the first mounting surface 51 of the printed circuit board 50, whereby the first mounting surface 51 is left leaving a portion where the solder paste p1 is desired to be applied. Covered by a mask. In this state, the solder paste p <b> 1 supplied on the mask is spread by a squeegee (not shown), and then the mask is removed from the first mounting surface 51. At this time, the mask is provided with holes at portions corresponding to the through holes 55 and the periphery thereof, the fixing through holes 56 and the periphery thereof, and the planned mounting positions of the other electronic components 30. Therefore, when this mask is overlaid on the first mounting surface 51, only the portion provided with the hole in the first mounting surface 51 is not covered with the mask, and therefore, after the solder paste p1 is spread by the squeegee When the mask is removed, the solder paste p1 is applied to the portion of the first mounting surface 51 with a constant thickness (mask thickness) (see FIG. 2B).

  The application amount of the through hole 55 on the first mounting surface 51 and the solder paste p1 applied around the through hole 55 is such that the terminal 12 is inserted into the through hole 55 and the outer peripheral surface of the terminal 12 and the inner peripheral surface of the through hole 55. In other words, the through hole 55 with the terminal 12 inserted therein can be filled with the solder h generated by melting the solder paste p1 with heat.

  Specifically, when the solder paste p1 applied to the first mounting surface 51 and the second mounting surface 52 is melted by the reflow process and flows into the through hole 55 as the solder h, both the mounting surfaces 51 and 52 are mounted. The total amount of solder inflow from the terminal 12 is determined so as to satisfy the space between the outer peripheral surface of the terminal 12 and the inner peripheral surface of the through hole 55. The application amount (application range) of the through hole 55 and the surrounding solder paste p1 on the first mounting surface 51 and the application amount of the through hole 55 and the surrounding solder paste p2 on the second mounting surface 52 in this embodiment. (Application range) is set to be equal. Thus, in order to solder the connector 10, the first mounting surface 51 is filled with an amount of solder paste p 1, p 2 necessary to fill the space between the outer peripheral surface of the terminal 12 and the inner peripheral surface of the through hole 55 with the solder h. And the second mounting surface 52 are applied separately, so that the solder paste on each mounting surface 51 (52) is compared to the case where the solder paste p1 (p2) is applied only to one mounting surface 51 (or 52). The application range of p1 and p2 can be narrowed. This makes it possible to mount the other electronic component 30 near the through hole 55 as compared with the manufacturing method of the electronic circuit unit in which the solder paste is applied only to one mounting surface.

  Also, the application amount (application range) of the fixing paste through hole 56 on the first mounting surface 51 and the solder paste p1 applied to the periphery thereof is the same as the application amount of the solder paste p1 to the through hole 55 and the periphery thereof. Determined.

<Arrangement process of other electronic components 30>
When the solder paste p1 is applied to the first mounting surface 51, as shown in FIG. 2 (C), another electronic component 30 is arranged at the intended mounting position where the solder paste p1 is applied.

<First reflow process>
As described above, when the solder paste p1 is applied to a predetermined portion of the first mounting surface 51 and another electronic component 30 is arranged at the planned mounting position, the printed circuit board 50 in this state is heated in a reflow furnace (not shown). (Reflow) is performed, and soldering of the other electronic component 30 to the first mounting surface 51 is performed.

  At this time, the solder paste p1 applied to the through hole 55 and the periphery thereof is melted by reflow to become the solder h, and the molten solder h flows into the through hole 55 by the surface tension. Similarly, the fixing through hole 56 and the solder paste p1 applied around the fixing through hole 56 are also melted by reflow to become solder h, and the melted solder h flows into the fixing through hole 56 by the surface tension.

<Cooling and reversal process>
The printed circuit board 50 subjected to the reflow process in the first reflow process is then cooled. Due to this cooling, the solder h at the planned mounting position is solidified, and the other electronic component 30 is electrically connected to the circuit and the like of the first mounting surface 51 via the solder h and the first mounting surface by the solder h. 51 is fixed. On the other hand, in the through hole 55, the solder h flowing in in the first reflow process is cooled and solidified. Similarly, in the fixing through hole 56, the solder h flowing in in the first reflow process is cooled and solidified. At this time, the through hole 55 and the fixing through hole 56 are closed by the solidified solder h (see FIG. 3A).

  The printed circuit board 50 cooled in this way is inverted so that the second mounting surface 52 is in an upward orientation (see 3 (A)).

<Printing process of solder paste p2 on the second mounting surface 52>
When the printed circuit board 50 is in the posture in which the second mounting surface 52 faces upward in the reversing step, the solder paste p2 is applied to the through hole 55 and the periphery thereof and the fixing through hole 56 and the periphery thereof on the second mounting surface 52. Each is applied. At this time, similarly to the application of the solder paste p1 to the first mounting surface 51, a mask (not shown) in which holes are provided in predetermined portions is used, and predetermined portions (through holes 55 and their surroundings) in the second mounting surface 52 are used. Then, the solder paste p2 is applied to the fixing through-hole 56 and the periphery thereof with a certain thickness.

  At this time, the application amount of the through hole 55 in the second mounting surface 52 and the solder paste p2 applied to the periphery thereof is set to the application amount of the through hole 55 in the first mounting surface 52 and the solder paste p1 applied to the periphery thereof. Determined based on. That is, when the solder pastes p1 and p2 applied to the first mounting surface 51 and the second mounting surface 52 are melted by the reflow process and flow into the through hole 55 as the solder h, both the mounting surfaces 51 and 52 are mounted. The total amount of inflow of solder from the terminal 12 is determined so that the space between the outer peripheral surface of the terminal 12 and the inner peripheral surface of the through hole 55 can be filled with the solder h. In this embodiment, as described above, the application amount (application range) of the through-hole 55 and the surrounding solder paste p1 on the first mounting surface 51 and the through-hole 55 and the surrounding solder paste p2 on the second mounting surface 52. The application amount (application range) is set to be equal.

  Further, the application amount (application range) of the fixing through hole 56 on the second mounting surface 52 and the solder paste p2 applied to the periphery thereof is the same as the application amount of the solder paste p2 to the through hole 55 and the periphery thereof. Determined.

<Arrangement process of connector 10>
When the solder paste p <b> 2 is applied to the second mounting surface 52, the connector 10 is disposed on the second mounting surface 52. Specifically, as shown in FIG. 3B, the connector 10 has the tip of the terminal 12 placed on the solder h solidified in the through hole 55 and the solder 10 solidified in the fixing through hole 56. The tip of the fixing member 20 is placed on the housing 14 so that each housing 12 and the fixing member 20 are legs, and the housing 14 is free-standing in a state where it floats from the second mounting surface 52. By arranging the connector 10 in this manner, the weight of the connector 10 is solidified in the solder h and the fixing through hole 56 which are solidified in the through hole 55 from the tip of the terminal 12 and the tip of the fixing member 20. Each solder h is in a state of being added.

<Second reflow process>
When the connector 10 is thus arranged on the second mounting surface 52, the printed circuit board 50 in this state is reflowed in a reflow furnace (not shown), and the soldering of the connector 10 to the second mounting surface 52 is performed. . Specifically, the printed circuit board 50 is in a posture in which the second mounting surface 52 faces upward and the connector 10 is self-supported on the second mounting surface 52 with the terminal 12 and the fixing member 20 as legs. Reflowed. The solder h solidified in the through hole 55 and the fixing through hole 56 is melted by the heat of the reflow. Since the weight of the connector 10 is applied to the solder h from the tip of the terminal 12 and the fixing member 20 placed on the solder h, when the solidified solder h is melted and softened, the terminals 12 and The through hole 55 and the fixing through hole 56 are lowered so that the front end of the fixing member 20 sinks into the solder h. As the terminal 14 and the through hole 55 of the fixing member 20 and the fixing through hole 56 are lowered, the bottom surface 16a of the housing 14 which is arranged in a state of floating from the second mounting surface 52 is the second mounting surface 52. Descend until it touches. At the same time, the solder paste p2 applied to the through hole 55 and the periphery thereof on the second mounting surface 52 and the fixing through hole 56 and the periphery thereof is melted to become the solder h, and the solder h becomes a through hole due to its surface tension. 55 and the fixing through hole 56 respectively.

  Thus, in the first reflow process and the second reflow process, the solder pastes p1 and p2 applied to both the mounting surfaces 51 and 52 of the printed circuit board 50 are melted to form the solder h in the through hole 55 and the fixing through hole 56, respectively. By flowing in, as shown in FIG. 3C, between the outer peripheral surface of the terminal 12 and the inner peripheral surface of the through hole 55 in a state where the terminal 12 is inserted into the through hole 55, and the fixing through hole The space between the outer peripheral surface of the fixing member 20 and the inner peripheral surface of the fixing through-hole 56 in a state where the fixing member 20 is inserted through 56 is filled with the solder h.

  Note that other electronic components 30 are already soldered and fixed to the first mounting surface 51 facing downward in the second reflow process, but these other electronic components 30 are fixed to the first mounting surface 51. The solder h that has been fixed in this manner is melted by the reflow in the second reflow process. However, these other electronic components 30 do not fall from the first mounting surface 51 due to the surface tension of the melted solder h.

<Cooling process>
The printed circuit board 50 that has been reflowed in the second reflow process is cooled. By this cooling, the solder h in the through hole 55 is solidified so that the terminal 12 and the through hole 55 are electrically connected via the solder h and the terminal 12 is fixed to the through hole 55, The solder h in the fixing through hole 56 is solidified in the same manner as the solder h in the through hole 55, and the fixing member 20 is fixed to the fixing through hole 56. Thereby, the connector 10 is fixed to the second mounting surface 52.

  In addition, the solder for fixing the other electronic component 30 to the first mounting surface 51 is solidified on the first mounting surface 51 melted in the second reflow process, and the other electronic component 30 is fixed to the first mounting surface 51. Is done.

  As described above, a plurality of electronic components (mounting components) 30 including the connector 10 are mounted on both mounting surfaces 51 and 52 of the printed circuit board 50. At this time, in order to solder the connector 10, an amount necessary to fill the space between the outer peripheral surface of the terminal 12 (fixing member 20) and the inner peripheral surface of the through hole 55 (fixing through hole 56) with the solder h. The solder pastes p1 and p2 are separately applied to the first mounting surface 51 and the second mounting surface 52, so that the solder paste p1 (p2) is applied only to one mounting surface 51 (or 52). Thus, the application range of the solder paste p1 (p2) on each mounting surface 51 (52) can be narrowed.

  Specifically, on the first mounting surface 51, the solder paste p1 for applying the solder paste p1 to the through hole 55 (fixing through hole 56) and the periphery thereof and mounting the other electronic component 30 at the planned mounting position is provided. Is applied, and another electronic component 30 is placed at the planned mounting position. Then, by reflowing (heating) the printed circuit board 50 in the first reflow process, another electronic component 30 is soldered to the first mounting surface 51, while the through hole 55 (fixing through hole 56) and The solder paste p1 applied to the periphery melts to become solder h and flows into the through hole 55 (fixing through hole 56) by surface tension. Next, solder paste p2 is applied to and around the through hole 55 (fixing through hole 56) of the second mounting surface 52, and the second mounting surface 52 is directed upward in the first reflow process. The tip of the terminal 12 (fixing member 20) is placed on the solder h that has flowed into the hole 55 (fixing through hole 56) and cooled and solidified in the through hole 55 (fixing through hole 56). The connector 10 is disposed. By reflowing (heating) in the second reflow process in this state, the solder h solidified in the through hole 55 (fixing through hole 56) is melted, and the inside of the through hole 55 (fixing through hole 56) is a terminal. 12 (fixing member 20) passes, and the through hole 55 (fixing through hole 56) in the second mounting surface 52 and the solder paste p2 applied to the periphery of the second mounting surface 52 melt and become solder, and the melted solder h It flows into the through hole 55 (fixing through hole 56) due to surface tension. In this way, the through holes 55 (fixing through holes 56) and the solder pastes p1 and p2 applied to the periphery of both of the first mounting surface 51 and the second mounting surface 52 contribute to the soldering of the connector 10. be able to. As a result, other mounting components are placed near the through hole 55 (fixing through hole 56) as compared with the manufacturing method of the electronic circuit unit in which the solder paste is applied only to one mounting surface 51 (or 52) of the printed circuit board 50. It can be implemented.

  In addition, the connector 10 of this embodiment includes a fixing member 20 whose tip protrudes toward the printed circuit board 50 side from the bottom surface 16a of the housing 14 in addition to the terminals 12, so that a support member is provided in the second arrangement step. Even without using the support means, the connector 10 can be stably and independently (ie, disposed) on the printed circuit board 50 using the terminals 12 and the fixing member 20 as legs. In addition, the self-weight of the connector 10 is applied from the distal end of the terminal 12 and the fixing member 20 to the portion on which the distal end of the terminal 12 and the distal end of the fixing member 20 are placed by being self-supporting as described above. State.

  In addition, the manufacturing method of the electronic circuit unit of this invention is not limited to said embodiment, Of course, various changes can be added within the range which does not deviate from the summary of this invention.

  In the above embodiment, the fixing member 20 is provided in the connector 10, but the fixing member 20 may not be provided. That is, it is only necessary that the connector 10 can be disposed on the second mounting surface 52 so that the tip of the terminal 12 is placed on the solder h solidified in the through hole 55 during the reflow in the second reflow process.

  In the above embodiment, only the connector 10 is mounted on the second mounting surface 52, but another electronic component (mounting component) 30 may be mounted. In this case, when the solder paste p <b> 2 is applied to the second mounting surface 52, the solder paste p <b> 2 for mounting the other electronic component 30 is applied to the position where the other electronic component 30 is to be mounted on the second mounting surface 52. Then, another electronic component 30 may be disposed at the planned mounting position of the second mounting surface 52 to which the solder paste p2 is applied.

  In the above-described embodiment, the mounting surface 51 (52) facing upward in the printing process of the solder paste p1 on the first mounting surface 51 and the printing process of the solder paste p2 on the second mounting surface 52. When the solder paste p1 (p2) is applied, if the solder paste p1 (p2) can be applied in a desired thickness and in a desired range, the solder paste p1 (p2) is applied. The mounting surface 51 (52) may face in any direction.

1 Electronic circuit unit 10 Connector 12 Connector terminal 14 Insulating housing (connector housing)
16a Bottom surface 20 Fixing member 30 Electronic component (mounting component)
50 printed circuit board 51 first mounting surface 52 second mounting surface 55 through hole 56 fixing through hole h solder p1, p2 solder paste

Claims (3)

A printed circuit board having a through-hole and a plurality of mounting parts mounted on the printed circuit board. The plurality of mounting parts include a connector terminal and the printed circuit board when mounted on the printed circuit board. A method of manufacturing an electronic circuit unit including a connector having a bottom surface in contact with a mounting surface, and a connector housing that holds the connector terminal so that a tip end portion projects from the bottom surface toward the mounting surface side Because
A first printing step of applying a solder paste to the through hole and its periphery on the first mounting surface which is one mounting surface of the printed circuit board;
A second printing step of applying a solder paste for mounting the other mounting component at a planned mounting position on the first mounting surface of the mounting component other than the connector;
A first arrangement step of arranging the other mounting component at the planned mounting position on the first mounting surface to which the solder paste is applied in the second printing step;
Solder paste applied in the first printing step is soldered by heating the printed circuit board in which the solder paste is applied in the first printing step and the other mounting components are arranged in the first arranging step. A first reflow step of fixing the other mounting component to the first mounting surface with the solder paste applied in the second printing step and flowing into the through hole as
After the first reflow step, a third printing step of applying a solder paste to the through hole and its periphery on the second mounting surface facing the opposite side of the first mounting surface of the printed board;
On the second mounting surface of the printed circuit board in a posture in which the second mounting surface coated with the solder paste in the third printing step faces upward, the second mounting surface is cooled in the through hole that has flowed in due to the heating in the first reflow step. A second arrangement step of arranging the connector so that the tip of the connector terminal is placed on the solidified solder;
By heating the printed circuit board in a state where the connector is disposed on the second mounting surface in the second arrangement step, the solidified solder is melted and the connector terminal placed on the connector terminal is heated. And a second reflow step of lowering the tip in the through hole and flowing the solder paste applied in the third printing step into the through hole as solder. In the manufacturing method of the electronic circuit unit according to claim 1,
The connector includes a fixing member that protrudes from the bottom surface in the same direction as the protruding direction of the tip of the connector terminal that protrudes from the bottom surface of the connector housing, and the fixing member is the first member in the second arrangement step. When the connector is disposed on the two mounting surfaces, the connector housing is supported in a state where the bottom surface faces the second mounting surface and floats from the second mounting surface in cooperation with the connector terminal;
The printed circuit board includes a fixing through hole having an inner diameter through which the fixing member can pass at a position corresponding to the fixing member when the connector is arranged on the second mounting surface in the second arrangement step. ,
In the first printing step, a solder paste is applied also to the fixing through hole and the periphery thereof on the first mounting surface,
In the first reflow process, due to the heating in the first reflow process, the through hole and the solder paste applied to the periphery of the first mounting surface flow into the through hole as solder and the fixing through Solder paste applied to the hole and its periphery flows into the fixing through hole as solder,
In the third printing step, a solder paste is applied also to the fixing through hole and the periphery thereof on the second mounting surface,
In the second arrangement step, the tip of the connector terminal is placed on the solder that is cooled and solidified in the through-hole that has flowed in by the heating in the first reflow step, and flows in by the heating in the first reflow step. The connector is arranged so that the tip of the fixing member is placed on the solder solidified by cooling in the fixing through hole,
In the second reflow step, the solder solidified in the through hole is melted by heating, and the tip of the connector terminal placed thereon is lowered in the through hole and applied in the third printing step. The solder paste is allowed to flow into the through-hole as solder, and the solidified solder in the fixing through-hole is melted to place the tip of the fixing member placed on the fixing through-hole into the fixing through-hole. And the solder paste applied in the third printing step is allowed to flow into the fixing through hole as solder. In the manufacturing method of the electronic circuit unit of Claim 1 or 2,
The method for manufacturing an electronic circuit unit, wherein the first printing step and the second printing step are performed simultaneously.

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