JP5950777B2 - Terminal and board connector connection structure - Google Patents

Description

The present invention relates to a connection structure for a terminal and a board connector .

  Conventionally, as a terminal inserted into a circular through hole formed so as to penetrate through a substrate, for example, one described in Patent Document 1 below is known. This terminal is formed by performing surface treatment using a wire having a square cross-section as a base material, and then cutting out to a certain length and pressing. When soldering by inserting a terminal into a through hole, the corner of the terminal cross section is closest to the inner wall of the through hole, so the hole diameter of the through hole is determined according to the cross sectional shape of the terminal. become. On the other hand, since the distance to the inner wall of the through hole is the longest at the center of each side in the cross section of the terminal, the amount of solder increases. Here, when soldering by flow soldering, it is possible to perform soldering by sucking up solder from the molten solder tank into the through hole, so even if the amount of required solder increases, the pitch between terminals Can be reduced.

JP 2010-277889 A

  However, in the case of reflow soldering in which solder paste is printed on the surface of the board and then soldered through a reflow furnace, the range wider than the land of the through hole, taking into account the amount of solder flowing into the through hole It is necessary to print the solder paste, and the pitch between the through holes must be set so that the solder pastes do not overlap. Therefore, in order to reduce the pitch between terminals, it is necessary to reduce the amount of solder as much as possible and to reduce the printing range of each solder paste as much as possible.

  The present invention has been completed based on the above circumstances, and the amount of solder required for connection in reflow soldering is reduced to reduce the printing range of each solder paste, thereby reducing the pitch between terminals. The purpose is to make it smaller.

The present invention is a terminal that is inserted into a through-hole formed in a substrate and connected by solder, the terminal having a polygonal cross section, and having a pair of surfaces that extend in the horizontal direction and are arranged in parallel. and which has each of the pair of tapered surfaces in the horizontal direction both side edges of the pair of surfaces are formed continuously, the horizontal dimensions of the pair of surfaces and L1, the horizontal dimensions of the tapered surface and L2 , L3 = L2 + L1 + L2, the difference between the through hole diameter and the outer diameter of the terminal is constant , and when L2 / L3 is defined as the chamfering ratio R, the chamfering ratio R is 0.30 or more and 0.35 or less. It is preferable.
The present invention also includes a plurality of through holes arranged in a straight line on the substrate at the same pitch, a plurality of terminals connected to the through holes, and a housing holding the plurality of terminals. terminal a connection structure of a circuit board connector disposed aligned linearly in the housing, the terminals are electrically connected to the through hole by soldering are inserted into the through holes, together with the pin forms a cross-sectional multi-angle shape A pair of contact surfaces that extend in the horizontal direction and are arranged in parallel to each other, and a terminal connection portion to which the counterpart terminal is connected to be conductive and a substrate connection portion that is connected to the through hole by solder. in a and has a pair of contact surfaces for contacting a mating terminal, horizontal in the horizontal respectively in directions opposite side edges and a pair of tapered surfaces are formed continuously, a pair of contact surfaces of the pair of contact surfaces Direction dimension is L And then, the horizontal dimensions of the tapered surface and L2, and L3 = L2 + L1 + L2, when defining the L2 / L3 chamfered ratio R, chamfering ratio R is preferably 0.23 or more 0.43 or less.

  The effect of the present invention will be described with reference to the graph of FIG. In FIG. 10, the horizontal dimension L3 of the terminal is set to 0.650 mm, and the difference between the through hole diameter and the maximum dimension of the terminal is set to 0.089 mm. Further, the chamfer dimension of the X axis in FIG. 10 corresponds to the “horizontal dimension L2 of the C plane” of the present invention. The Y-axis solder amount is the amount of solder paste required for reflow soldering. Furthermore, R-attachment is a terminal having a cross-sectional shape in which an R surface is formed at a corner, and the C surface is a terminal having an octagonal cross-section in which a C surface is formed at a corner. Is a terminal having a hexagonal cross section in which a tapered surface is formed at a corner.

  In FIG. 10, when the chamfer ratio R is 0.23 (from L2 = R × 0.65), the chamfer dimension is 0.150 mm. Further, when the chamfer ratio R is 0.43, the chamfer dimension is 0.275 mm. That is, in the range where the chamfer dimension is 0.150 mm or more and 0.275 mm or less, the amount of solder paste can be reduced on the C surface than on the hexagon.

  Further, the chamfer ratio R is more preferably 0.30 or more and 0.35 or less. When the chamfer ratio R is 0.30, the chamfer dimension is 0.200 mm. Further, when the chamfer ratio R is 0.35, the chamfer dimension is 0.225 mm. That is, in the range where the chamfer dimension is 0.200 mm or more and 0.225 mm or less, the amount of solder paste can be reduced on the C surface rather than on the R surface.

  According to the present invention, it is possible to reduce the printing range of each solder paste by reducing the amount of solder required for connection in reflow soldering, thereby reducing the pitch between terminals.

Front view of board connector in the embodiment Left side view of board connector Bottom view of board connector Sectional view showing the state before inserting the terminal into the through hole Sectional view showing the state after inserting the terminal into the through hole Sectional view of the terminal and through-hole connection section cut in the vertical direction after reflow Sectional drawing showing dimensions of C-plane terminal with chamfer dimension of 0.200mm Sectional drawing showing each dimension of R-attached terminal with R dimension of 0.200mm Sectional drawing showing dimensions of hexagonal terminal with chamfer dimension of 0.200mm Graph showing the relationship between R and chamfer dimensions and solder amount Sectional drawing which shows the connection state of C surface terminal and chamfering dimension of 0.100mm Sectional drawing which showed the connection state of the C surface terminal with a chamfer dimension of 0.150 mm and a through hole Sectional drawing which shows the connection state of C surface terminal and chamfering dimension of 0.200mm Sectional drawing which showed the connection state of the C surface terminal of chamfering dimension 0.250mm, and a through hole Sectional drawing which showed the connection state of the C surface terminal of chamfering dimension 0.275mm, and a through hole

<Embodiment>
An embodiment of the present invention will be described with reference to the drawings of FIGS. As shown in FIG. 1, the connector in the present embodiment is a board connector that is mounted on a board B, and includes a housing 50 made of synthetic resin and a plurality of terminals 10 held by the housing 50. Has been. The housing 50 has a hood portion 51 that opens forward, and a plurality of terminals 10 are arranged side by side in the vertical direction and the left-right direction so as to protrude forward from the back wall 52 of the hood portion 51. A mating connector (not shown) can be fitted inside the hood portion 51.

  The terminal 10 is formed by performing a surface treatment such as tin plating using a wire made of copper or a copper alloy as a base material, and then cutting out the substrate with a certain length and performing a pressing process or the like. The terminal 10 includes a terminal connection portion 11 that protrudes forward from the back wall 52 of the hood portion 51, and a board connection portion 12 that protrudes downward from the back wall 52 of the hood portion 51. When the mating connector is fitted inside the hood 51, the mating terminal provided on the mating connector is connected to the terminal connection portion 11 so as to be conductive.

  Although not illustrated, the mating terminal has a box portion having a rectangular tube shape, and an elastic contact piece having a cantilever shape is formed inside the box portion. When the terminal 10 is fitted inside the box portion, the terminal 10 is sandwiched between the elastic contact piece and the ceiling wall disposed facing the elastic contact piece. The terminal connection portion 11 of the terminal 10 includes a lower contact surface 13 that contacts the elastic contact piece and an upper contact surface 14 that contacts the ceiling wall, so that the upper and lower contact surfaces 13 and 14 are parallel to each other. It is arranged. In addition, since the terminal 10 is formed from the same wire, not only the terminal connection part 11 but also the board connection part 12 includes upper and lower side contact surfaces 13 and 14, and the tip part 15 of the board connection part 12. Is formed in a tapered shape.

  Next, a method for connecting the substrate connecting portion 12 to the through hole B1 by solder B2 by reflow will be described. First, the substrate B is placed on the substrate table of the printing machine, and after fixing the substrate B, a mask in which a round hole is formed at the position of the through hole B1 is brought into close contact with the substrate B. Then, by pressing and moving the squeegee against the mask, the solder paste is embedded in the round hole, and the solder paste is printed on the through hole B1. As shown in FIG. 4, the solder paste B3 is printed in a range wider than the land of the through hole B1, and when the board connecting portion 12 is inserted into the through hole B1, the solder paste B3 is formed as shown in FIG. A part is pushed into the through hole B1. Subsequently, when the substrate B is heated through a reflow furnace, as shown in FIG. 6, solder B2 is formed, and fillets are formed in the land portions on the upper and lower sides of the through hole B1.

  Now, the terminal 10 of this embodiment has an octagonal cross section as shown in FIGS. The board connecting portion 12 of the terminal 10 is inserted into a through hole B1 formed through the board B and connected by solder B2. On the other hand, in the terminal connection part 11, it is necessary to form so that the dimension between the upper and lower contact surfaces 13 and 14 may become constant so that the bending amount of the elastic contact piece of the other party terminal may become constant. Further, the inner diameter of the through hole B1 must be formed larger than the outer diameter of the terminal 10 so that the corner portion of the board connecting portion 12 does not contact the inner wall of the through hole B1.

  Therefore, in the present embodiment, the minimum clearance formed between the corner portion of the substrate connecting portion 12 and the inner wall of the through hole B1 is 0.089 mm, and the dimension between the upper and lower contact surfaces 13 and 14 (terminal 10). Under the precondition that the thickness of the terminal is 0.640 ± 0.010 mm, the terminal shape was optimized as to which terminal shape would minimize the amount of solder.

  First, each dimension in the cross-sectional shape of the terminal will be described with reference to FIGS. The terminal in FIG. 7 is a terminal having an octagonal cross section in which a C surface is formed at a corner, and is hereinafter referred to as a C surface terminal 20. 7 to 9, the horizontal direction is the horizontal direction. The C-plane terminal 20 has a pair of contact surfaces 21 extending in the horizontal direction and arranged in parallel. The terminal in FIG. 8 is a terminal having a cross-sectional shape in which an R surface is formed at a corner, and is hereinafter referred to as an R-attached terminal 30. The R-attached terminal 30 has a pair of contact surfaces 31 extending in the horizontal direction and arranged in parallel. The terminal of FIG. 9 is a terminal having a hexagonal cross section in which a tapered surface is formed at a corner, and is hereinafter referred to as a hexagonal terminal 40. The hexagonal terminal 40 has a pair of contact surfaces 41 extending in the horizontal direction and arranged in parallel.

L1 in FIG. 7 is a dimension in the horizontal direction of the contact surface 21 of the C-plane terminal 20, and is hereinafter referred to as a contact surface dimension L1. A pair of C-surfaces 22 are continuously formed on both side edges of the C-surface terminal 20 in the horizontal direction. Both C surfaces 22 are formed symmetrically with respect to the contact surface 21 at an inclination angle of 45 °. L2 is a dimension in the horizontal direction of the C surface 22, and is hereinafter referred to as a chamfer dimension L2. The chamfer dimension L2 corresponds to C0.025 to C0.325 of C surface treatment in Table 1. Therefore, for example, C0.025 in Table 1 means that the chamfer dimension L2 is 0.025 mm. CL, which has a difference between the outer diameter D _TER of the through hole diameter D _TH and C face terminal 20 divided by 2, which corresponds to the minimum clearance in Table 1. L4 is a dimension between the pair of contact surfaces 21 and 21, and corresponds to the thickness of the terminal in Table 1. On the other hand, L3 is a dimension calculated by the equation L3 = L2 + L1 + L2, and corresponds to the terminal width in Table 1.

The C-plane terminal 20 shown in FIG. 11 has a chamfer dimension L2 of 0.100 mm. As shown in Table 1, the amount of solder at this time is 0.472 mm ³ . The C-plane terminal 20 shown in FIG. 12 has a chamfer dimension of 0.150 mm, and the amount of solder at this time is 0.396 mm ³ . The C-plane terminal 20 shown in FIG. 13 has a chamfer dimension of 0.200 mm, and the amount of solder at this time is 0.362 mm ³ . The C surface terminal 20 shown in FIG. 14 has a chamfer dimension L2 of 0.250 mm, and the amount of solder at this time is 0.371 mm ³ . The C-surface terminal 20 shown in FIG. 15 has a chamfer dimension L2 of 0.275 mm, and the amount of solder at this time is 0.392 mm ³ .

  As can be seen from the C-plane terminal 20 of FIGS. 11 to 15, when the chamfer dimension L2 is set to 0.200 mm to 0.250 mm, the cross-sectional shape approaches a perfect circle from a square, so the amount of solder decreases. I can see it going. However, if the chamfering dimension L2 is excessively increased, the contact surface dimension L1 is decreased, so that an increase in contact resistance must be considered.

L1 in FIG. 8 is a dimension in the horizontal direction of the contact surface 31 of the R-attached terminal 30, and is hereinafter referred to as a contact surface dimension L1. A pair of R surfaces 32 are formed on both side edges of the R-attached terminal 30 in the horizontal direction. Both R surfaces 32 are formed symmetrically. L2 is a dimension in the horizontal direction of the R surface 32, and is hereinafter referred to as a chamfer dimension L2. This chamfer dimension L2 corresponds to R0.025 to R0.32 of R treatment in Table 2. Therefore, for example, R0.025 in Table 2 means that the chamfer dimension L2 is 0.025 mm. CL, which has a difference between the outer diameter D _TER of the through hole diameter D _TH and R with the terminal 30 is divided by 2, which corresponds to the minimum clearance in Table 2. L4 is a dimension between the pair of contact surfaces 31, 31 and corresponds to the thickness of the terminal in Table 2. On the other hand, L3 is a dimension calculated by the equation L3 = L2 + L1 + L2, and corresponds to the terminal width in Table 2.

図１０は、面取り寸法を０ｍｍ以上０．３２５ｍｍ以下の範囲で変化させた場合における半田ペーストの量の推移を、Ｃ面端子２０とＲ付け端子３０と６角形端子４０とについて比較したものである。また、図１０のグラフの元データは、表４に記載したとおりである。表４の単位のうち面取り寸法はｍｍであり、他はｍｍ²であり、表４においては単位を省略して記載してある。

まず、Ｃ面端子２０の傾向としては、面取り寸法Ｌ２が０．２００ｍｍ以上０．２２５ｍｍ以下のときに、最も半田ペーストの量が少なくなることがわかる。また、６角形端子４０の傾向としては、０．２２５ｍｍ以上０．２７５ｍｍ以下のときに、最も半田ペーストの量が少なくなることがわかる。一方、Ｒ付け端子３０については、面取り寸法Ｌ２を大きくするほど半田ペーストの量が少なくなることがわかる。これは、Ｒ付け端子３０の面取り寸法Ｌ２を大きくすれば大きくするほど、断面形状が真円形状に近づくためである。 L1 in FIG. 9 is a dimension in the horizontal direction of the contact surface 41 of the hexagonal terminal 40, and is hereinafter referred to as a contact surface dimension L1. A pair of tapered surfaces 42 are formed on both side edges of the hexagonal terminal 40 in the horizontal direction. Both the tapered surfaces 42 are formed to be bilaterally symmetrical with a steeper slope than the C surface 22 of the octagonal terminal 20. L2 is a dimension in the horizontal direction of the tapered surface 42, and is hereinafter referred to as a chamfer dimension L2. The chamfer dimension L2 corresponds to the hexagonal 0.025 × 0.3 to 0.325 × 0.3 in Table 3. Here, for example, 0.025 × 0.3 means that the chamfer dimension L2 is 0.025 mm and the dimension of the tapered surface 42 in the vertical direction is 0.3 mm. CL is the difference between the through-hole diameter _DTH and the outer diameter _DTER of the hexagonal terminal 40 divided by 2, and corresponds to the minimum clearance in Table 3. L4 is a dimension between the pair of contact surfaces 41 and 41, and corresponds to the thickness of the terminal in Table 3. On the other hand, L3 is a dimension calculated by the equation L3 = L2 + L1 + L2, and corresponds to the terminal width in Table 3.

FIG. 10 compares the transition of the amount of solder paste when the chamfer dimension is changed in the range of 0 mm or more and 0.325 mm or less for the C-face terminal 20, the R-attached terminal 30, and the hexagonal terminal 40. . In addition, the original data of the graph of FIG. 10 is as described in Table 4. Of the units in Table 4, the chamfer dimension is mm, and the others are mm ^{2. In} Table 4, the units are omitted.

First, as a tendency of the C-plane terminal 20, it can be seen that when the chamfer dimension L2 is 0.200 mm or more and 0.225 mm or less, the amount of solder paste is the smallest. Further, as a tendency of the hexagonal terminal 40, it can be seen that the amount of the solder paste is the smallest when it is 0.225 mm or more and 0.275 mm or less. On the other hand, for the R-attached terminal 30, it can be seen that the amount of solder paste decreases as the chamfer dimension L2 increases. This is because the larger the chamfer dimension L2 of the R-attached terminal 30 is, the closer the cross-sectional shape is to a perfect circle shape.

  However, if the chamfer dimension L2 is increased, it means that the contact surface dimension L1 in the terminal connection portion 11 fitted to the mating connector is reduced accordingly. Therefore, from the viewpoint of preventing an increase in contact resistance, the chamfering dimension L2 is reduced. The dimension L2 is preferably as small as possible, and it can be said that it is ideal that the amount of solder paste can be reduced while the chamfer dimension L2 is small. Then, it can be said that the C surface terminal 20 that can reduce the amount of the solder paste when the chamfer dimension L2 is small is most ideal.

When the chamfer dimension L2 of the C surface terminal 20 is 0.150 mm, the amount of solder paste is 0.792 mm ³ , and when the chamfer dimension L2 is 0.275 mm, the amount of solder paste is 0.783 mm ³ , When the dimension L2 is 0.150 mm or more and 0.275 mm or less, the amount of solder paste is suppressed to 0.800 m ³ or less. On the other hand, the amount of the solder paste of the hexagonal terminal 40 is the smallest when the chamfer dimension L2 is 0.250 mm, and the amount is 0.813 mm ³ . Therefore, it can be seen that if the chamfer dimension L2 of the C-plane terminal is set to 0.150 mm or more and 0.275 mm or less, the amount of solder paste of the hexagonal terminal 40 can be surely reduced.

Here, (chamfer dimension L2) / (terminal width L3) is defined as a chamfer ratio R. Further, as described in Tables 1 to 3, the terminal width L3 is 0.64 mm ± 0.01 mm, and when the upper limit value of 0.650 mm is L3, the chamfer ratio is R is calculated as follows.
<When chamfer dimension L2 is 0.150 mm>
Chamfer ratio R = L2 / L3 = 0.150 / 0.650 = 0.231
<When chamfer dimension L2 is 0.275 mm>
Chamfer ratio R = L2 / L3 = 0.275 / 0.650 = 0.423
Therefore, if the chamfering ratio R is set to 0.23 or more and 0.43 or less, the chamfering dimension L2 necessarily includes the range of 0.150 mm or more and 0.275 mm or less. Therefore, if the chamfering ratio R is set to 0.23 or more and 0.43 or less, the amount of solder paste can be reduced in the C surface terminal 20 than in the hexagonal terminal 40.

Furthermore, when the chamfer dimension L2 of the C-face terminal 20 is 0.200 mm, the amount of solder paste is 0.725 mm ³ , and when the chamfer dimension L2 is 0.225 mm, the amount of solder paste is 0.725 mm ³ . . Therefore, if the chamfer dimension L2 is set to 0.200 mm or more and 0.225 mm or less, the amount of solder paste for the C-plane terminal 20 can be further reduced. When the chamfer dimension L2 is 0.225 mm, the amount of solder paste on the R-attached terminal 30 is 0.769 mm ³ , so that the amount of solder paste on the C-face terminal 20 can be smaller than that on the R-attached terminal 30. The chamfer ratio R when the chamfer dimension L2 is 0.200 mm and 0.225 mm is as follows.
<When chamfer dimension L2 is 0.200 mm>
Chamfering ratio R = L2 / L3 = 0.200 / 0.650 = 0.308
<When chamfer dimension L2 is 0.225 mm>
Chamfer ratio R = L2 / L3 = 0.225 / 0.650 = 0.346
Therefore, if the chamfering ratio R is set to 0.30 or more and 0.35 or less, the chamfering dimension L2 necessarily includes the range of 0.200 mm or more and 0.225 mm or less. Therefore, if the chamfering ratio R is set to 0.30 or more and 0.35 or less, the amount of solder paste on the C-plane terminal 20 can be minimized, and the amount of solder paste can be less than that on the R-attached terminal 30. it can.

  If the amount of solder paste can be reduced in this way, the pitch between through holes can be reduced, and the pitch between terminals can be reduced.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the above embodiment, the amount of solder paste is calculated on the precondition that the minimum clearance CL is 0.089 mm and the terminal width and thickness are 0.64 ± 0.01 mm. The minimum clearance CL and the width and thickness of the terminal are not limited to these.

DESCRIPTION OF SYMBOLS 10 ... Terminal 20 ... C surface terminal 21 ... Contact surface 22 ... C surface B ... Board | substrate B1 ... Through-hole B2 ... Solder CL ... Minimum clearance (Difference with a through-hole diameter and a terminal outer diameter)
D _TER ... outside diameter of terminal D _TH ... through hole diameter L1 ... contact surface dimension (horizontal dimension of contact surface)
L2 ... Chamfer dimension (horizontal dimension of C surface)
L3 ... terminal width (L2 + L1 + L2)
R ... Chamfer ratio

Claims (2)

A terminal that is inserted into a through hole formed in the substrate and connected by solder,
Together with the pin forms a polygonal section, has a pair of surfaces disposed in parallel and extending in a horizontal direction, a pair of tapered surfaces respectively formed continuously in the horizontal direction both side edges of the pair of surfaces And
The pair of the horizontal dimension of the surface and L1, the and the horizontal dimensions of the tapered surface L2, and L3 = L2 + L1 + L2, the difference between the outer diameter of the through hole diameter the terminals is constant,
A terminal characterized in that, when L2 / L3 is defined as a chamfer ratio R, the chamfer ratio R is 0.30 or more and 0.35 or less. A plurality of through holes are arranged in a straight line on the substrate at the same pitch, and have a plurality of terminals connected to the through holes and a housing holding the plurality of terminals, and the plurality of terminals are A board connector connection structure arranged in a straight line in a housing,
The terminal is inserted into the through hole and electrically connected to the through hole with solder,
Together with the pin forms a cross-sectional multi-angle shape, includes a terminal connection portion which mating terminals are electrically conductively connected, and a board connecting portion which is the connection by soldering to the through hole, the terminal connecting portion, the horizontal A pair of contact surfaces that extend in the direction and are arranged in parallel and have a pair of contact surfaces that come into contact with the counterpart terminal, and a pair of tapered surfaces on each side edge in the horizontal direction of the pair of contact surfaces. Formed continuously,
The horizontal dimension of the pair of contact surfaces is L1, the horizontal dimension of the tapered surface is L2, and L3 = L2 + L1 + L2.
When L2 / L3 is defined as a chamfering ratio R, the chamfering ratio R is 0.23 or more and 0.43 or less.

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