Male connector having solder barrier layer and connector assembly

A male connector is attached to a circuit board and fits with a female connector in a fitting direction perpendicular to a surface of the circuit board. A terminal of the male connector extends outside a housing thereof in parallel to the circuit board. The terminal has a connection portion to be connected with a circuit portion of the circuit board with solder. When the male connector and the female connector are fitted with each other, the connection portion has a facing region facing a top face of a peripheral wall of a housing of the female connector. The terminal includes a solder barrier layer formed at least in a nearest facing region of the facing region. The nearest facing region is situated to be closest to the top face.

BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT

The present invention relates to a male electrical connector to be attached to a circuit board (hereinafter called “male connector”) and an electrical connector assembly for a circuit board (hereinafter called “connector assembly”) having the male electrical connector and a female electrical connector (hereinafter called “female connector”) to be attached to another circuit board.

Publication Reference has disclosed a connector assembly for a circuit board. According to Publication Reference, each of a male connector and a female connector is attached to a circuit board. Further, the male connector and the female connector are fitted with each other to connect in a direction perpendicular to a surface of the circuit board. Accordingly, when the male connector and the female connector are fitted, the circuit boards become parallel to each other. A terminal of the male connector forms a connection portion in a portion that extends outside a housing thereof along a surface of the circuit board. Further, the connection portion is connected to a corresponding circuit portion of the circuit board with solder.

Publication Reference: Japanese Utility Model Publication No. 3055703

In the female connector, a peripheral wall of a housing is situated outside with respect to a fitting portion of the male connector. Further, a top face of the peripheral wall faces a connection portion of the male connector. The top face of the peripheral wall is adjacent to and faces the connection portion of a terminal of the male connector.

The terminal of the male connector is connected with the circuit portion of the circuit board with solder in the connection portion. Molten solder rises from a solder connection surface of the connection portion due to surface tension. Further, the molten solder may reach a surface other than the solder connection surface that is tangent to the circuit portion. That is, a phenomenon called a “solder rising” occurs.

The molten solder rises to a side edge surface of the connection portion due to the solder rising; thereby forming a fillet shape portion between a side edge surface and a surface of the circuit portion, thereby improving strength of the solder connection.

The solder rising does not stop at the side edge surface of the connection portion. Instead, the solder rising proceeds further to reach a facing region in which the solder connection surface faces an opposite side surface of the solder connection surface, or a top face of a peripheral wall of the female connector (mating connector).

Further, a swelling in the facing region of the connection portion may be formed there. The solder connection of the connection surface can be visually confirmed due to the solder rising. On the other hand, the connection portion may collide with the top face of the housing peripheral wall of the female connector due to the solder swelling in the facing region of the connection portion, thereby making it difficult to fit the male connector and the female connector.

To this end, in Publication Reference, a space is formed as an escape portion, so that it is easy to fit the male connector and the female connector even when the male connector has the solder swelling in the connection portion. The escape portion is recessed from the top face of the housing peripheral wall of the female connector.

According to Publication Reference, the escape portion of the female connector can prevent a trouble caused by the solder swelling in the connection portion of the terminal of the male connector. It should be noted, however, that it is necessary to provide the escape portion with a depth sufficiently larger than an expected amount of the solder swelling to certainly prevent the trouble. When a size of the escape portion increases, a size of the female connector increases as well in a fitting direction unless a special attention is paid to a size and an arrangement of the terminal.

As described above, the solder swelling caused by the solder rising can inhibit a complete fitting of the male connector and the female connector. Further, when an automatic quantitative soldering is conducted, an amount of the solder may become insufficient in the solder connection portion by an amount corresponding to the solder rises, thereby decreasing the connection strength. Accordingly, the escape portion of the female connector may prevent the problem in the first case, but does not in the latter case.

In view of the problems described above, an object of the present invention is to provide a male connector for a circuit board and a connector assembly comprising the male connector and a female connector for a circuit board. In the present invention, it is possible to prevent the male connector from insufficiently fitting to the female connector, and to provide solder with a sufficient amount in a solder connection portion. Further, it is possible to minimize a solder rising and maintain strength of a fillet shape portion.

Further objects of the invention will be apparent from the following description of the invention.

SUMMARY OF THE INVENTION

In order to attain the objects described above, according to the present invention, a male connector is attached to a circuit board and fits with a female connector in a fitting direction perpendicular to a surface of the circuit board. A terminal of the male connector extends outside a housing thereof in parallel to the surface of the circuit board. The terminal has a connection portion that is connected with a circuit portion of the circuit board with solder. When the male connector and the female connector are fitted with each other, the connection portion has a facing region which faces a top face of a peripheral wall of a housing of the female connector in the fitting direction.

According to the present invention, the terminal includes a solder barrier layer formed at least in a nearest facing region of the facing region of the connection portion of the terminal. The nearest facing region is situated to be closest to the top face of the peripheral wall in the fitting direction.

In the present invention, the solder barrier layer is a surface layer of the terminal that is provided as a region in which molten solder has poor solderability property with respect to the terminal.

In general, the terminal is plated with nickel as a base layer. The nickel plated layer has poor solderability property and is not suitable as the solder connection portion of the terminal. Accordingly, the terminal is often plated with copper or gold on a top of the nickel plate. The copper or gold plated surface has good solderability property.

In this case, for example, a partial region that is not plated with copper or gold may be provided. A surface layer of such a region becomes a layer plated with nickel, which can be a solder barrier layer.

In the present invention, a material forming the solder barrier layer or a method of forming the solder barrier layer is not limited, and may be operable by any publicly known method. For example, a surface layer may be formed of an oxide layer, a resist ink, and the like as the solder barrier layer. It is sufficient that a material having poorer solderability than that of a portion to be connected to the terminal with solder is provided as the solder barrier layer in the nearest facing region.

In the present invention, the solder barrier layer is formed at least in the nearest facing region of the facing region in which the connection portion of the terminal of the male connector faces the female connector. Accordingly, a solder swelling due to solder rising does not occur in the nearest facing region.

Accordingly, it is easy to fit the male connector to the female connector to a specific depth. Further, an influence of a solder shortage in the solder connection surface is minimized. At the same time, the solder barrier layer is not provided on a side edge surface of the connection portion, thereby allowing the solder rising. Accordingly, the solder connection strength is sufficiently obtained in the fillet shape portion.

According to the present invention, it is preferred that the solder barrier layer in the nearest facing region extends from a portion on a base portion side toward a peripheral surface of the terminal in a band shape in an extending direction of the connection portion. The solder barrier layer having a band shape revolves around the peripheral surface.

Accordingly, the solder barrier layer prevents solder from traveling from the connection portion of the terminal to the base portion side at any position in a circular direction of the terminal. Further, the solder barrier layer having a band shape is situated on the base portion side in the extending direction. Accordingly, almost an entire range in the connection portion has good solderability, thereby ensuring solder strength.

According to the present invention, it is preferred that the nearest facing region be formed on the base portion side in the extending direction of the connection portion. Accordingly, the solder swelling is prevented in an inner range in the connection portion extending direction more than in a portion in which the nearest facing region is provided, thereby ensuring a sufficient fitting depth of the male connector in the range.

In this case, a facing direction distance with the female connector outside the range is longer than that of the range. Accordingly, the fitting of the male connector is not inhibited even when the solder swelling occurs outside the range. Further, the solder connection portion has a sufficient amount of solder and connection strength is improved due to the solder rising. Further, solder can be visually confirmed.

According to the present invention, a connector assembly comprises the male connector and the female connector. The male connector and the female connector are attached to the respective circuit boards and fitted with each other in the fitting direction perpendicular to the surfaces of the circuit boards.

Further, the connector assembly includes at least the connection portion and the facing region. In the connection portion, the terminal of the male connector extends outwardly from the housing thereof in parallel to the surface of the circuit board. Further, the connection portion is connected to the circuit portion of the circuit board with solder. In the facing region, the connection portion of the terminal of the male connector faces the top face of the peripheral wall of the housing of the female connector in the fitting direction when the male connector and the female connector are fitted with each other.

According to the present invention, the connector assembly includes the solder barrier layer d at least in the nearest facing region in which the connection portion of the terminal of the male connector is situated nearest to the peripheral wall top face in the fitting direction of the facing region.

As described above, the solder barrier layer is provided in the nearest facing region in the connection portion of the terminal of the male connector. Accordingly, there is no solder swelling in the region. Further, the fitting of the connector assembly is ensured up to a specific depth. Accordingly, the connectors are connected with each other securely. Further, a height of the connector assembly in the fitting direction does not have to be excessively large in consideration of the solder swelling, thereby reducing a size of the connector assembly in the direction.

According to the present invention, the peripheral wall top face of the housing of the female connector may be formed so that a portion that corresponds to the facing region of the connection portion of the terminal of the male connector comprises an adjacent portion that corresponds to the nearest facing region and a residual portion. The residual portion is recessed from the adjacent portion in the fitting direction.

In this case, the connection portion of the terminal of the male connector is provided with the solder barrier layer in the nearest facing region and there is no solder swelling there. Accordingly, the male connector and the female connector are fitted with each other up to a specific depth without any obstructions. The solder barrier layer is not necessarily provided in a region other than the nearest facing region. Accordingly, there can be the solder swelling. When the residual portion is recessed from the adjacent portion in the female connector, it is easy to deal with the solder swelling.

According to the present invention, it is preferred that the terminal of the male connector be formed of a metal band body bending in a plate thickness direction thereof. Further, it is preferred that a terminal of the female connector be formed of a metal sheet maintaining a flat plate surface thereof.

In the configuration described above, the plate thickness direction of the connection portion of the terminal of the male connector is aligned with the fitting direction of the male connector, and the plate surface becomes the solder connection surface. Accordingly, an area of the solder connection surface is enlarged, thereby increasing the solder connection strength and reducing a size of the connector assembly in the fitting direction due to the solder barrier layer.

As described above, according to the present invention, the solder barrier layer is provided in the nearest facing region of the facing region that faces the female connector in the connection portion of the terminal of the male connector. The male connector is connected to the circuit board with solder. Further, the facing region that faces the female connector is situated on the opposite side of the solder connection surface.

Accordingly, it is possible to prevent the solder rising to the nearest facing region, and no solder swelling occurs in the region. Accordingly, the male connector can be very close to or adjacent to the housing peripheral wall of the female connector in the region, thereby making it easy to fit the male connector to the female connector.

Further, the connectors can be low-profiled. Further, there is no solder rising; thereby preventing the solder connection strength from being deteriorated without causing a shortage of solder in the solder connection portion. In addition, the solder rising occurs from the solder connection surface on the side edge surface of the connection portion in which the solder barrier layer is not provided. Accordingly, the fillet shape portion is provided there, thereby ensuring the solder connection strength.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereunder, embodiments of the present invention will be explained with reference to the accompanying drawings.

In the embodiment, a connector assembly comprises a male connector and a female connector. The male connector and the female connector are fitted with each other to be connected. Each of the male connector and the female connector is attached to a circuit board, so that surfaces of the circuit boards are parallel to each other. Further, the male connector and the female connector are fitted with each other in a direction perpendicular to the surfaces of the circuit boards.

In the embodiment, the male connector has a housing portion having a protruding shape, while the female connector has a housing portion having a recess shape. A contact portion of a terminal that is attached to the housing is situated in the housing portion. The male connector and the female connector are fitted with each other at the protruding portion and the recess portion described above, so that the contact potions contact with each other. Accordingly, the male connector and the female connector are electrically connected.

FIG. 1is a perspective view showing a male connector10according to an embodiment of the present invention. InFIG. 1, a circuit board to which the male connector10is attached is not shown. A recess portion12is formed in a center portion of a housing11of the male connector10. The housing11is flat and has a planar shape of approximate rectangle. Further, a peripheral wall13that protrudes from the housing11is provided in the male connector10. The peripheral wall13comprises two sidewalls14in a longitudinal direction of the housing11and edge walls15that connect the sidewalls14on the both edges of the longitudinal direction.

A plurality of a terminal20is arranged and held at specific intervals in the longitudinal direction of the sidewall14. A metal fixture26is attached to be adjacent to the terminal20that is arranged on each edge of the rows of the plurality of the terminal20. The terminal20and the metal fixture26will be explained below.

Dent portions15A are formed in center positions of the edge walls15of the housing11. The dent portion15pierces the edge wall15in the longitudinal direction in which the sidewalls14extend. Further, the dent portion15opens upward.

The male connector10connects the dent portions15A of the edge walls15that face each other. Further, the male connector10is symmetrical with respect to an axis line that extends in the longitudinal direction. Further, the male connector10is symmetrical with respect to a centerline that is perpendicular to the axis line in a center of the longitudinal direction thereof.

As shown inFIG. 1, the male connector10is attached to a circuit board P1. The terminal20of the male connector10is made through bending and forming a metal member having a band shape in a plate thickness direction thereof. Further, the terminals20are arranged and held at specific intervals in the sidewalls14of the housing11.

FIGS. 3(A) and 3(B)are sectional views showing the male connector10and the female connector30taken along a line that passes through the terminals. More specifically,FIG. 3(A)is a sectional view showing the male connector10and the female connector30before the male connector10is fitted into the female connector30.FIG. 3(B)is a sectional view showing the male connector10and the female connector30after the male connector10is fitted into the female connector30.

The male connector10shown inFIGS. 3(A) and 3(B)faces with respect to the female connector30, a mating connector in a fitting direction. That is, the male connector10is vertically flipped from that shown inFIG. 1.

The terminal20comprises an attached portion21, a contact portion22, and a connection portion23. The attached portion21is formed to fit into a terminal holding groove16from the top face of the sidewall14of the housing11(a top face inFIG. 1, a lower surface inFIG. 3(A)).

The terminal holding groove16is formed to extend to the inner and outer wall surfaces of the sidewall14. The contact portion22is formed in the inner and outer surfaces of the attached portion21. The connection portion23is bent in an L-character shape outside of the sidewall14and extends along a surface of the circuit board P1. The contact portion22comprises a first contact portion22A and a second contact portion22B.

In the embodiment, the first contact portion22A is formed inside of the sidewall14, or the inner surface that faces the recess portion12. Further, the second contact portion22B is situated outside of the sidewall14. Locking portions22A-1and22B-1are provided in the first contact portion22A and the second contact portion22B, respectively, in order to maintain a stable contact position with a corresponding contact portion of the terminal of the female connector, or the mating connector. The locking portions22A-1and22B-1are slightly recessed.

When the male connector10is fitted into the female connector30, the connection portion23has a region that faces the housing of the female connector30on the opposite surface of the surface that is tangent to the circuit board P1.

The female connector30will be explained below. In the embodiment, the region is called a “facing region”. In the embodiment, a surface of the facing region is a surface layer24, which has poorer solderability than that of surfaces of the other portions. The surface layer with poor solderability is called a solder barrier layer24.

A corresponding portion of the housing of the female connector that the facing region faces in the embodiment can form a surface having a step shape. In the embodiment, a portion of the facing region that is nearest to the corresponding portion is called the nearest facing region. Similarly, when the connection portion forms a surface having a step shape, the region in which the facing surfaces are nearest to each other is called the nearest facing region.

In the embodiment, the terminal20is nickel plated as an under layer. Further, the terminal20is copper plated or gold plated. The copper plate and the gold plate have good conduction and solderability, while the nickel plate has poor solderability.

In the embodiment, the nickel plate as an under layer is exposed to form the solder barrier layer24while preventing a necessary portion of the facing region from being copper plated or gold plated.

FIG. 4is an enlarged perspective view showing the connection portion23of the male connector10according to the embodiment of the present invention. As shown inFIG. 4, a whole surface of a material23A of the connection portion23is plated with a nickel plate23B as an under layer. The material23A has a flat band shape. Further, the whole surface of the material23A of the connection portion23except the facing region is further plated with a gold plate23C.

A required portion of the facing region is masked after plated with the nickel plate23B as an under layer. Further, the terminal is gold plated. When the masking is removed, the nickel plate23B forms the solder barrier layer24in the required portion of the facing region.

FIG. 5is an enlarged perspective view showing a modified example of the connection portion23of the male connector10according to the embodiment of the present invention. As shown inFIG. 5, the solder barrier layer24ofFIG. 4further have a revolving solder barrier layer24A. The revolving solder barrier layer24A extends in a band shape on a surrounding surface of the connection portion23.

In the embodiment, each of the metal fixtures26is attached to the sidewall14, along with the terminals20, on the outer positions with respect to an arrangement range of a set of the terminals20that is arranged and held on the sidewalls14of the housing11. The metal fixture26is manufactured in a similar way with the terminal20except that the metal fixture26does not have a contact portion.

The metal fixture26comprises an attached portion26A and a fixed portion26B. The attached portion26A is bent in the plate thickness direction thereof to form an L-character shape. Further, the attached portion26A is attached to and held by a holding groove that is formed on an outer surface of the sidewall14of the housing11. The fixed portion26B extends in parallel and along with the connection portion23of the terminal20.

Similar to the connection portion23of the terminal20, the fixed portion26B is connected to the circuit board P1with solder on the surface that faces the circuit board P1. The surface of the opposite side is the facing region that faces the female connector. Accordingly, similar to the case of the terminal20, the facing region is provided with a solder barrier layer.

In the embodiment, the female connector30that receives the male connector10has an appearance as shown inFIG. 2and a section as shown inFIG. 3(A).

As shown inFIG. 2, the female connector30is attached to a circuit board P2(not shown inFIG. 2) when used. Further, terminals50and a metal fixture58are attached to a housing31.

The housing31is provided with a receiving recess portion32inside of a peripheral wall33. The peripheral wall33comprises two sidewalls34and edge walls35. The sidewall34extends in a longitudinal direction. The longitudinal direction is a terminal arrangement direction. The edge wall35is provided on each end of the longitudinal direction. Further, the housing31has a protruding portion36having an island shape.

The protruding portion36is surrounded by the receiving recess portion32. The connecting portions37connect the protruding portion36to the edge walls35to reinforce on both ends of the longitudinal direction. The receiving recess portion32receives the peripheral wall13of the male connector10. Further, the protruding portion36fits into the recess portion12of the male connector10.

At that time, the connecting portion37enters into the dent portion15A of the male connector10. Further, a top face34A of the sidewall34is recessed in a step shape with respect to a top face35A of the edge wall35. When the male connector10and the female connector30are fitted with each other, the facing region of the connection portion23of the terminal20of the male connector10is substantially tangent to the top face34A of the sidewall34of the female connector30.

The terminal50of the female connector30has an outer shape in which a metal sheet is processed while maintaining the planarity of the metal sheet. As shown inFIG. 3(A), the terminal50of the female connector30is held by the housing31at a position that corresponds to the terminal20of the male connector10in the longitudinal direction.

As shown inFIG. 3(A), the terminal50comprises a base portion51, a first contact arm52, a second contact arm53, a first attached arm54, a second attached arm55, a third attached arm56, and a connection portion57.

The base portion51is positioned in a lower surface of the housing31and extends to be parallel to the lower surface. The first contact arm52and the second contact arm53extend upward from the base portion51in a middle portion of a direction in which the base portion51extends. The first attached arm54, the second attached arm55, and the third attached arm56extend upward from the base portion51on both sides with respect to the first contact arm52and the second contact arm53, respectively. Further, the base portion51extends outside of the housing to form the connection portion57. Further, a first contact portion52A and a second contact portion53A are formed in the first contact arm52and the second contact arm53, respectively.

The first contact portion52A and the second contact portion53A face each other and protrude on the top edges thereof. The first attached arm54is situated on a backside of the first contact arm52. Further, the first attached arm54is positioned in a center side of the connector.

The second attached arm55and the third attached arm56are situated on a back of the second contact arm53. Further, the second attached arm55and the third attached arm56are positioned near an outer side of the connector. The first contact arm52and the second contact arm53have an elasticity to bend in a direction in which the first contact portion52A and the second contact portion53A are away from each other, respectively. The first contact arm52and the second contact arm53are bent when a contact pressure is received from the terminal20of the male connector10, the mating connector, in the first contact portion52A and the second contact portion53A, respectively.

In the embodiment, metal fixtures58are attached to corresponding grooves of the housing31outside of arrangement ranges of the terminals50. The metal fixture58has a plate shape. Further, a lower edge of the metal fixture is exposed from a bottom surface of the connector to be fixed to the circuit board with solder.

Terminal holding grooves38are formed in the housing31to correspond to a shape of the terminals50. The terminal holding groove38is situated in a position that corresponds to each terminal20of the male connector10in a longitudinal direction of the housing31and holds the terminal50there. As shown inFIG. 3(A), a bottom groove39covers a range from the protruding portion36to the sidewall34in the terminal holding groove38in the lower surface of the housing31. Further, branched grooves of a variety extend upward.

As shown inFIG. 3(A), an inner holding groove40and an outer holding groove41are formed to open toward the receiving recess portion32on an inner surface of the wall portion of the receiving recess portion32. The inner holding groove40and the outer holding groove41face each other and extend upward from the bottom groove39of terminal holding groove38.

A first holding groove42, a second holding groove43, and a third holding groove44are provided on the opposite side of the receiving recess portion32with respect to the inner holding groove40. The first holding groove42extends inside of the protruding portion36having an island shape and passes through upward. The second holding groove43extends inside of the sidewall34. The third holding groove44is provided on an outer surface of the sidewall34.

The first contact arm52and the second contact arm53of the terminal50are stored in the inner holding groove40and the outer holding groove41of the terminal holding groove38, respectively. The first attached arm54is stored in the first holding groove42. Further, the second attached arm55and the third attached arm56are stored in the second holding groove43and the third holding groove44, respectively.

The first attached arm54is loosely fitted into the first holding groove42. The second attached arm55is pressed to fit into the second holding groove43. The third attached arm56is pressed by a bottom surface of the third holding groove44. Accordingly, the terminal50is held.

The male connector10and the female connector30of the embodiment are constituted as described. The male connector10and the female connector30are used as described below.

First, the male connector10and the female connector30are attached to the circuit boards P1and P2, respectively. That is, the male connector10and the female connector30are connected to the respective corresponding circuit portion in the connection portion23of the terminal20and the connection portion57of the terminal50, respectively, with solder. Further, the metal fixture26of the male connector10and the metal fixture58of the female connector30are fixed to the respective corresponding portion of the circuit board with solder.

When the terminal20of the male connector10is connected with the corresponding circuit portion of the circuit board P1in the connection portion23with solder, molten solder connects the male connector10and the circuit board P1in the tangent area of the connection portion23and the corresponding circuit portion with solder. Further, the molten solder reaches the side faces of the connection portion23in which a fillet portion is formed. Accordingly, a contact area between the connection portion23and the corresponding circuit portion is increased; and thereby improving the electrical property and strengthening a retention force in the circuit board of the connector.

The molten solder can further rise from the side faces of the connection portion23to a free surface on the opposite side of the tangent area; that is, the facing region. Further, the molten solder can rise from the free surface to the base portion of the connection portion23. In the embodiment, however, as shown inFIGS. 1,3(A), and4, the solder barrier layer24is provided in the facing region that is the free surface of the connection portion23. Accordingly, even if the molten solder rises from the side faces of the connection portion23, the molten solder does not reach the facing region. Accordingly, the solder does not adhere to the facing region or is not swollen due to an adhesion. Similarly, the solder is not swollen in the fixed portion26B of the metal fixture26of the male connector.

As shown inFIG. 5, when the revolving solder barrier layer24A is provided, the molten solder does not proceed toward the housing side of the revolving solder barrier layer24A.

Accordingly, as shown inFIG. 3(B), the male connector10that is attached to the circuit board P1and the female connector30that is attached to the circuit board P2are fitted with each other in a direction perpendicular to the surfaces of the circuit boards P1and P2so that the circuit boards P1and P2are parallel to each other.

In the male connector10, the two contact portions22, or the first contact portion22A and the second contact portion22B, of the terminal20that are supported on the sidewalls14enter inside of the receiving recess portion32of the female connector30. Further, the protruding portion36of the female connector30enters into the recess portion12of the male connector10. The protruding portion36has an island shape.

Accordingly, the first contact portion22A and the second contact portion22B elastically contact with the first contact portion52A and the second contact portion53A of the two contact arms of the terminal50, or the first contact arm52and the second contact arm53, respectively. The facing region in which the connection portion23of the terminal20of the male connector10faces the top face of the sidewall34of the female connector30contacts or becomes near the top face. Accordingly, the connectors are completely fitted with each other to a specific depth.

The present invention is not limited to the embodiments shown inFIGS. 1 to 5, and various changes can be made.FIG. 6is an enlarged perspective view showing another modified example of the connection portion23of the male connector10according to the embodiment of the present invention.

First, in the male connector10, as shown inFIG. 6, it is not necessary to form a solder barrier layer in the distal area23C when the connection portion23extends long in the facing region of the connection portion23of the terminal20and the distal area23C does not face the top face34A of the sidewall34of the housing31of the female connector30, the mating connector.

The solder barrier layer24can be formed except the distal area23C. Solder swelling occurs in the distal area23C. Accordingly, the solder connection at the connection portion23becomes stronger. Further, the solder connection can be visually confirmed with ease due to the solder swelling. Accordingly, when the solder barrier layer24is formed except the distal area23C, the revolving solder barrier layer24A can be formed as in the case ofFIG. 5.

FIG. 7is an enlarged perspective view showing a further modified example of the connection portion23of the male connector10according to the embodiment of the present invention. It is preferred that the revolving solder barrier layer24A be formed near a border position with the second contact portion22B.FIG. 7shows a case in which the solder barrier layer is not formed in the distal area23C in the revolving solder barrier layer24A.

FIGS. 8(A) and 8(B)are sectional views showing the male connector10and the female connector30according to another embodiment of the present invention. More specifically,FIG. 8(A)is a sectional view showing the male connector10and the female connector30before the male connector10is fitted into the female connector30, andFIG. 8(B)is a sectional view showing the male connector10and the female connector30after the male connector10is fitted into the female connector20.

In the female connector30, when the solder barrier layer24is formed only in a portion of the base portion side of the connection portion23of the terminal20of the male connector10in the extending direction of the connection portion23, as shown inFIG. 8(A), the top face34A of the sidewall34of the housing31is formed to be in a step shape and a residual portion34A-2is recessed with respect to an adjacent portion34A-1. A portion that corresponds to the solder barrier layer24is the adjacent portion34A-1with respect to the solder barrier layer24. An area that corresponds to the adjacent portion34A-1with respect to the male connector10is the nearest facing region.

Accordingly, the connection portion23of the terminal20of the male connector10can broaden the distal area in which the solder barrier layer is not formed. As a result, the solder swelling improves the connection strength. Further, solder can be confirmed visually with ease. Further, the residual portion34A-2that corresponds to the distal area is recessed from the adjacent portion34A-1in the sidewall34of the housing31of the female connector30. Accordingly, even if there is solder swelling, as shown inFIG. 8(B), the solder swelling is not adjacent to the top face34A of the sidewall34upon fitting of the connectors. That is, the fitting of the connectors is not inhibited.

The disclosure of Japanese Patent Application No. 2007-150054, filed on Jun. 6, 2007 is incorporated in the application by reference.