Electrical connector

Abstract

An electrical connector (1) comprises: receptacle assemblies (2U, 2L) provided with contact pins (21U, 21L) and insulating housings (22U, 22L); a shell (4) which is made of metal and holds the receptacle assemblies (2U, 2L); and a cover (5) attached to the shell (4). The cover (5) is provided with: a bottom plate (51); an insertion hole (53) which is formed in the bottom plate (51) and through which a cylindrical portion (42) of the shell (4) is inserted; and through holes (57, 58) which are formed in order to expose a body portion (41) of the shell (4) to the outside.

Description

Electrical Connector Cross - reference to related applications

[0001] This application claims priority based on Japanese Patent Application No. 2025 - 026181 (invention name: “Electrical Connector”) filed on February 20, 2025, and further, the content of this Japanese patent application is hereby incorporated by reference in its entirety into this specification.

[0002] The present invention generally relates to an electrical connector, and more specifically, to an electrical connector used to provide a coaxial connection with a coaxial cable.

[0003] In order to provide an electrical connection via a cable between an electronic device and another electronic device, a combination of a receptacle connector and a plug connector is widely used. Also, with the improvement in the processing power of electronic devices in recent years, the amount of data transmitted from an electronic device to another electronic device via a cable has been increasing. In order to transmit a large amount of data in a short time, it is necessary to transmit a high - frequency signal via a cable, and there is a need to improve the signal transmission characteristics of the cable, particularly the signal transmission characteristics of the cable in the high - frequency band. In response to such needs, coaxial cables having high signal transmission characteristics in the high - frequency band are widely used. As is well known, a coaxial cable has a coaxial structure in which a core wire for transmitting a signal, an inner insulating layer covering the core wire, an outer conductor layer (braided layer) covering the inner insulating layer, and an outer insulating layer covering the outer conductor layer are concentrically arranged.

[0004] In order to provide such a coaxial connection with a coaxial cable, an electrical connector including a contact pin electrically connected to the core wire of the coaxial cable, an insulating housing that holds the contact pin inside, a metal shell that covers the housing from the outside, and a cover attached to the shell is widely used. For example, Patent Document 1 discloses a receptacle - type electrical connector 500 as shown in FIG. 1. FIG. 1 is a perspective view showing the electrical connector 500. FIG. 2 is a perspective view of the cover 540 of the electrical connector 500.

[0005] As shown in Figure 1, the electrical connector 500 includes a pair of contact pins 510, an insulating housing 520 that holds the pair of contact pins 510 spaced apart from each other, a metal shell 530 that covers the housing 520 from the outside, and an insulating cover 540 that covers the shell 530 from the outside. The shell 530 includes a box-shaped main body 531, a cylindrical portion 532 that extends from the front end of the main body 531 toward the front end and into which the housing 520 is inserted, and four ground terminals 533 that extend downward from the lower end of the main body 531.

[0006] As shown in Figure 2, the cover 540 of the electrical connector 500 includes a bottom plate 541 facing the front end surface of the main body portion 531 of the shell 530, a cylindrical portion 542 extending from the bottom plate 541 toward the front end, an insertion hole 543 formed in the bottom plate 541 that penetrates in the insertion / removal direction of the mating connector, through which the cylindrical portion 532 of the shell 530 is inserted, and a pair of protruding pieces 544 extending from the bottom plate 541 toward the base end of the cover 540. As shown in Figure 1, when the cover 540 is attached to the shell 530, the front end surface of the main body portion 531 of the shell 530 is covered from the front end by the bottom plate 541. In addition, a pair of sides of the main body portion 531 are covered by the pair of protruding pieces 544. In this way, several areas of the main body portion 531 are covered by the cover 540 and are not exposed to the outside.

[0007] The electrical connector 500 is mounted on the circuit board of any device, with the terminal portion 511 of the contact pin 510 and the ground terminal 533 of the shell 530 connected to the corresponding terminals. A plug-type mating connector, connected to the end of a coaxial cable, is inserted into the electrical connector 500 from the tip end, connecting the electrical connector 500 and the mating connector. When the electrical connector 500 and the mating connector are connected, the contact portion 512 of the contact pin 510 contacts the contact pin of the mating connector, and further, the cylindrical portion 532 of the shell 530 contacts the metal outer contact of the mating connector. This provides a coaxial connection between the circuit board on which the electrical connector 500 is mounted and the coaxial cable to which the mating connector is connected, via the electrical connector 500 and the mating connector.

[0008] In order to mount the electrical connector 500 onto the circuit board, a reflow process is performed. In the reflow process, first, the ground terminals 533 are inserted into the boss holes (terminal holes) formed on the circuit board. Then, hot air is applied to the electrical connector 500 and the circuit board to melt the solder paste filled in the boss holes and to perform soldering between the ground terminals 533 and the terminals provided in the corresponding boss holes. By applying hot air, the surface temperature of the metal shell 530 rises, and the solder in the boss holes melts. As a result, the ground terminals 533 and the terminals provided in the corresponding boss holes on the circuit board are joined, and an electrical connection is established between the electrical connector 500 and the circuit board.

[0009] However, as shown in Figure 1, the hot air does not directly hit the portion of the shell 530 that is covered by the cover 540 (for example, the tip surface of the main body portion 531 of the shell 530 or the portion covered by the protruding piece 544 on the side of the main body portion 531). Therefore, as the area of ​​the shell 530 covered by the cover 540 increases, the area of ​​the shell 530 exposed to the outside decreases, and the surface area that is directly hit by the hot air decreases, resulting in a problem in which the efficiency of raising the surface temperature of the shell 530 in the reflow process decreases.

[0010] Furthermore, if the surface area of ​​the shell 530 exposed to the outside is small, the surface temperature of the shell 530 does not rise easily, and in the reflow process, it is necessary to apply hotter hot air to raise the temperature to the desired level within a predetermined time. However, if the temperature of the hot air is excessively high in the reflow process, expansion and deformation of the shell 530 and cover 540 occur, causing instability in the electrical connection between the electrical connector 500 and the mating connector, and between the electrical connector 500 and the circuit board, resulting in a decrease in the contact reliability of the electrical connector 500. In addition, overheating of the circuit board can cause expansion, deformation, or damage to the circuit board, increasing the risk of short circuits and connection failures, and impairing the contact reliability of the circuit board.

[0011] Japanese Patent Publication No. 2024-107626

[0012] This invention addresses the above-mentioned conventional problems, and its objective is to provide an electrical connector with high contact reliability by enabling a reflow process with lower temperature hot air when mounting the electrical connector to a circuit board, thereby preventing expansion, deformation, or damage due to overheating of the electrical connector and circuit board.

[0013] Such objectives are achieved by the present invention as defined in (1) below: (1) An electrical connector connectable to a mating connector inserted from the tip side, comprising: a receptacle assembly comprising: contact pins and an insulating housing that houses the contact pins inside; a metal shell that holds the receptacle assembly; and a cover attached to the shell to guide the connection of the mating connector to the electrical connector, wherein the shell comprises: a box-shaped body portion and a cylindrical portion extending from the body portion toward the tip side into which the receptacle assembly is inserted; and the cover comprises: a bottom plate facing the body portion of the shell from the tip side; a cylindrical portion extending from the bottom plate toward the tip side; an insertion hole formed in the bottom plate so as to penetrate in the insertion / removal direction of the mating connector and through which the cylindrical portion of the shell is inserted; and a through hole formed to expose the body portion of the shell to the outside.

[0014] In the electrical connector of the present invention, since the shell is exposed to the outside through a through hole formed in the cover, the surface area of ​​the shell exposed to the outside is increased, and the surface area exposed to hot air during the reflow process is increased. As a result, the efficiency of raising the surface temperature of the shell is improved, and the rise in the surface temperature of the shell proceeds more effectively and uniformly. Consequently, the reflow process can be performed with lower temperature hot air, which prevents expansion, deformation, or damage due to overheating of the electrical connector and circuit board, and improves the contact reliability of the electrical connector. Furthermore, since the reflow process can be performed with lower temperature hot air, the energy cost of the reflow process can be reduced.

[0015] Figure 1 is a perspective view showing a conventional electrical connector. Figure 2 is a perspective view of the cover of the electrical connector shown in Figure 1. Figure 3 is a perspective view showing the electrical connector of the present invention and a circuit board on which the electrical connector of the present invention is mounted. Figure 4 is a perspective view showing the electrical connector of the present invention. Figure 5 is a perspective view of the electrical connector of the present invention from a different angle. Figure 6 is a cross-sectional view of the YZ plane including the contact pins of the electrical connector shown in Figure 4. Figure 7 is an exploded perspective view of the electrical connector shown in Figure 4. Figure 8 is an exploded perspective view of the upper receptacle assembly of the electrical connector shown in Figure 4. Figure 9 is a perspective view of the housing of the upper receptacle assembly shown in Figure 8 from a different angle. Figure 10 is an exploded perspective view of the lower receptacle assembly of the electrical connector shown in Figure 4. Figure 11 is a perspective view of the housing of the lower receptacle assembly shown in Figure 10 from a different angle. Figure 12 is a cross-sectional view of the XZ plane of the electrical connector along the line A-A shown in Figure 4. Figure 13 is a perspective view of the shell of the electrical connector shown in Figure 4. Figure 14 is a perspective view of the shell of the electrical connector shown in Figure 13, viewed from a different angle. Figure 15 is a perspective view of the cover of the electrical connector shown in Figure 4. Figure 16 is a perspective view of the cover shown in Figure 15, viewed from a different angle. Figure 17 is a perspective view showing the covers shown in Figures 15 and 16 attached to the shells shown in Figures 13 and 14. Figure 18 is a perspective view of the cover and shell shown in Figure 17, viewed from a different angle. Figure 19 is a diagram showing a modified example of the cover shown in Figure 15. Figure 20 is a cross-sectional view of the electrical connector in the XZ plane along the line B-B shown in Figure 4.

[0016] The electrical connector of the present invention will be described below based on preferred embodiments shown in the accompanying drawings. The figures referenced below are schematic diagrams prepared for the purpose of explaining the present invention. The dimensions (length, width, thickness, etc.) of each component shown in the drawings do not necessarily reflect the actual dimensions. In each figure, the same or corresponding elements are given the same reference numeral. In the following description, the positive direction of the Z axis in each figure may be referred to as the "tip side" or "front side," the negative direction of the Z axis may be referred to as the "base side" or "rear side," the positive direction of the Y axis may be referred to as the "upper side," and the negative direction of the Y axis may be referred to as the "lower side." In addition, the Z direction may be referred to as the "front-back direction" or "insertion / removal direction of the mating connector," the Y direction may be referred to as the "height direction," and the X direction may be referred to as the "width direction."

[0017] Figure 3 is a perspective view showing the electrical connector of the present invention and a circuit board on which the electrical connector of the present invention is mounted. Figure 4 is a perspective view showing the electrical connector of the present invention. Figure 5 is a perspective view of the electrical connector of the present invention from a different angle. Figure 6 is a cross-sectional view of the YZ plane including the contact pins of the electrical connector shown in Figure 4. Figure 7 is an exploded perspective view of the electrical connector shown in Figure 4. Figure 8 is an exploded perspective view of the upper receptacle assembly of the electrical connector shown in Figure 4. Figure 9 is a perspective view of the housing of the upper receptacle assembly shown in Figure 8 from a different angle. Figure 10 is an exploded perspective view of the lower receptacle assembly of the electrical connector shown in Figure 4. Figure 11 is a perspective view of the housing of the lower receptacle assembly shown in Figure 10 from a different angle. Figure 12 is a cross-sectional view of the XZ plane of the electrical connector along the line A-A shown in Figure 4. Figure 13 is a perspective view of the shell of the electrical connector shown in Figure 4. Figure 14 is a perspective view of the shell of the electrical connector shown in Figure 13 from a different angle. Figure 15 is a perspective view of the cover of the electrical connector shown in Figure 4. Figure 16 is a perspective view of the cover shown in Figure 15 from a different angle. Figure 17 is a perspective view showing the covers shown in Figures 15 and 16 attached to the shells shown in Figures 13 and 14. Figure 18 is a perspective view of the cover and shell shown in Figure 17 from a different angle. Figure 19 shows a modified example of the cover shown in Figure 15. Figure 20 is a cross-sectional view of the electrical connector in the XZ plane along the B-B line shown in Figure 4.

[0018] As shown in Figure 3, the electrical connector 1 of the present invention is a receptacle connector mounted on a circuit board 100 provided within any device. When mating connectors (plug connectors) attached to the ends of four coaxial cables, each having a pair of core wires, are inserted into the electrical connector 1 from the end side, and the electrical connector 1 and the mating connectors are connected, an electrical connection is provided between the four coaxial cables and the circuit board 100 via the electrical connector 1 and the mating connectors.

[0019] In the illustrated configuration, the electrical connector 1 includes two pairs of upper receptacle assemblies 2U and lower receptacle assemblies 2L arranged side by side in the height direction of the electrical connector 1. However, the electrical connector 1 is not limited to this configuration; it may include at least one pair of upper receptacle assemblies 2U and lower receptacle assemblies 2L arranged side by side in the height direction.

[0020] Furthermore, in the illustrated embodiment, the electrical connector 1 comprises an upper receptacle assembly 2U with a pair of upper contact pins 21U and a lower receptacle assembly 2L with a pair of lower contact pins 21L, but the present invention is not limited thereto. Embodiments in which each of the two upper receptacle assemblies 2U comprises one or more upper contact pins 21U, and each of the two lower receptacle assemblies 2L comprises one or more lower contact pins 21L are also within the scope of the present invention. Hereinafter, the description will be provided assuming that the electrical connector 1 is a multi-pin connector (8-pin connector) for automotive Ethernet, comprising two pairs of upper receptacle assemblies 2U and lower receptacle assemblies 2L arranged side by side in the lateral direction, each of the upper receptacle assemblies 2U comprising a pair of upper contact pins 21U, and each of the lower receptacle assemblies 2L comprising a pair of lower contact pins 21L.

[0021] As shown in Figures 3 to 7, and in particular in Figure 7, the electrical connector 1 includes two lower receptacle assemblies 2L, two upper receptacle assemblies 2U located above and at the base end of the two lower receptacle assemblies 2L, a shielding member 3 located between the lower receptacle assemblies 2L and the upper receptacle assemblies 2U, a metal shell 4 that holds the two lower receptacle assemblies 2L, the two upper receptacle assemblies 2U, and the shielding member 3, and a cover 5 attached to the tip portion of the shell 4 to guide the connection of the mating connector to the electrical connector 1.

[0022] The two lower receptacle assemblies 2L and the two upper receptacle assemblies 2U are held by the shell 4 and are connected to the corresponding plug assemblies of the mating connector, respectively. As shown in Figure 6, when held by the shell 4, one lower receptacle assembly 2L and one upper receptacle assembly 2U are paired and aligned in the height direction. The upper receptacle assembly 2U is also held by the shell 4 so that it is positioned above and at the base end of the corresponding lower receptacle assembly 2L.

[0023] Since the two upper receptacle assemblies 2U have the same configuration as each other, one upper receptacle assembly 2U will be described in detail below as a representative example. As shown in Figure 8, the upper receptacle assembly 2U includes a pair of upper contact pins 21U, each in contact with a corresponding contact pin of the mating connector, and an insulating upper housing 22U that holds the pair of upper contact pins 21U.

[0024] Each of the pair of upper contact pins 21U is an L-shaped member made of a conductive material such as a copper alloy. When the electrical connector 1 and the mating connector are connected, the upper contact pins 21U come into contact with the corresponding contact pins of the mating connector, providing an electrical connection between the mating connector and the electrical connector 1. Since each of the pair of upper contact pins 21U has the same configuration, the configuration of the upper contact pin 21U located on the +X side will be described in detail below as a representative example.

[0025] The upper contact pin 21U includes a horizontal extension portion 211 that extends linearly in the front-rear direction (Z direction), a downward extension portion 212 that extends linearly downward from the base end of the horizontal extension portion 211, a contact portion 213 that extends linearly from the tip end of the horizontal extension portion 211 toward the tip, and a terminal portion 214 that extends linearly downward from the lower end of the downward extension portion 212.

[0026] The horizontal extension portion 211 is a plate-like portion that extends linearly in the front-rear direction. The downward extension portion 212 is a plate-like portion that extends linearly downward from the base end of the horizontal extension portion 211. As shown in Figure 6, when the upper contact pin 21U is press-fitted into the corresponding insertion hole 223 formed in the cylindrical portion 221 of the upper housing 22U, the horizontal extension portion 211 is positioned inside the cylindrical portion 221, and furthermore, the downward extension portion 212 is positioned inside the downward extension portion 222 of the upper housing 22U.

[0027] Returning to Figure 8, the contact portion 213 is a cylindrical portion that extends linearly from the tip of the horizontal extension portion 211 toward the tip. Also, when the upper contact pin 21U is held by the upper housing 22U, the contact portion 213 protrudes toward the tip from the cylindrical portion 221 of the upper housing 22U and is exposed. When the electrical connector 1 and the mating connector are connected, the contact portion 213 contacts the corresponding contact pin of the mating connector, providing an electrical connection between the mating connector and the electrical connector 1.

[0028] The terminal portion 214 is formed to protrude downward from the lower end of the downward extension portion 212, and its lower end is a rod-shaped portion with a substantially conical shape. When the upper contact pin 21U is held by the upper housing 22U, the terminal portion 214 extends downward from the downward extension portion 222 of the upper housing 22U and is exposed. The terminal portion 214 is connected to the corresponding terminal 120 (see Figure 3) of the circuit board 100 on which the electrical connector 1 is mounted.

[0029] The upper contact pin 21U described above is press-fitted into the insertion hole 223 of the upper housing 22U and held by the upper housing 22U. The upper housing 22U is made of an elastic insulating material such as a resin material (for example, liquid crystal polymer (LCP)). As shown in Figures 8 and 9, the upper housing 22U includes a cylindrical portion 221 that extends in the front-rear direction (Z direction) and a downwardly extending portion 222 that extends downward from the base end of the cylindrical portion 221.

[0030] The cylindrical portion 221 is a cylindrical part that extends linearly in the front-rear direction. In a plan view from the Z direction, the cylindrical portion 221 has a rounded rectangular planar shape. In a plan view from the Z direction, the length of the cylindrical portion 221 in the width direction (X direction) is greater than the length in the height direction (Y direction). The upper and lower surfaces of the cylindrical portion 221 are flat surfaces that extend in the front-rear direction, spaced apart from each other, while the two surfaces of the cylindrical portion 221 in the X direction are curved surfaces that extend in the front-rear direction, spaced apart from each other.

[0031] The cylindrical portion 221 includes a pair of grooves 2211 formed on the upper and lower surfaces of the cylindrical portion 221, a pair of through holes 223 penetrating the cylindrical portion 221 in the front-rear direction, four first pressing ribs 224 located on the upper and lower surfaces of the cylindrical portion 221 and extending in the front-rear direction, a pair of second pressing ribs 225 located on both sides of the cylindrical portion 221 in the X direction and extending in the front-rear direction, a block portion 226 provided on the lower surface of the cylindrical portion 221 so as to protrude downward, and an engaging recess 227 formed on the block portion 226 so as to open downward.

[0032] The pair of grooves 2211 are located on the upper and lower surfaces of the cylindrical portion 221 and are recesses formed to extend linearly from the tip to the base of the cylindrical portion 221. The pair of grooves 2211 are located between two first pressing ribs 224 formed on the upper surface of the cylindrical portion 221 and between two first pressing ribs 224 formed on the lower surface of the cylindrical portion 221. The pair of grooves 2211 are provided to facilitate the elastic deformation of the cylindrical portion 221 when the cylindrical portion 221 is inserted into the corresponding through hole 43 of the shell 4. Furthermore, the pair of grooves 2211 have the function of maintaining a constant distance between each upper contact pin 21U and the cylindrical portion 42 of the shell 4 by fitting with a corresponding pair of protrusions of a mating connector (not shown). As a result, the electric field distribution of the electrical connector 1 becomes uniform and the capacitance of the entire electrical connector 1 becomes constant. As a result, local impedance fluctuations within the electrical connector 1 are suppressed, and the impedance stabilizes, thereby improving the signal transmission characteristics of the electrical connector 1.

[0033] The pair of through holes 223 are arranged in parallel in the width direction, spaced apart from each other, and extending linearly in the front-rear direction. Each of the pair of through holes 223 penetrates the cylindrical portion 221 in the front-rear direction. A pair of upper contact pins 21U are press-fitted into the pair of insertion holes 223. The through holes 223 have a shape corresponding to the horizontally extended portion 211 of the upper contact pins 21U, and in a plan view from the Z direction, they have a substantially rectangular planar shape.

[0034] The four first pressing ribs 224 are formed to prevent the upper contact pin 21U from shifting toward the base end or detaching from the insertion hole 223 of the upper housing 22U, and to prevent the cylindrical portion 221 from detaching from the insertion hole 43, when the cylindrical portion 221 of the upper housing 22U is inserted into the insertion hole 43 of the shell 4. The four first pressing ribs 224 are projections that extend linearly in the front-rear direction while being spaced apart from each other. Two of the four first pressing ribs 224 are formed on the upper surface and two on the lower surface of the cylindrical portion 221. As shown in Figure 8, each of the four first pressing ribs 224 is a stepped projection whose height increases in stages from the tip side to the base side, and the base end side of the first pressing rib 224 is a high-backed portion with a greater projection in the Y direction than the tip side.

[0035] As shown in Figure 6, when the upper housing 22U is held by the shell 4, the height (length in the Y direction) of the first pressing rib 224 is set such that at least a portion of the outer surface (the surface perpendicular to the Y direction) of the first pressing rib 224 (the raised back portion on the base end side of the first pressing rib 224) contacts the inner circumferential surface of the insertion hole 43 of the shell 4. In addition, the base ends of the two first pressing ribs 224 formed on the lower surface of the cylindrical portion 221 are connected to the front end surface of the block portion 226.

[0036] In a natural state where no external force is applied to the upper housing 22U, the sum of the outer diameter of the cylindrical portion 221 in the height direction (Y direction) and the height (protrusion amount) of the pair of first pressing ribs 224 is slightly larger than the inner diameter of the insertion hole 43 of the shell 4 in the Y direction. With this configuration, when the cylindrical portion 221 is inserted into the insertion hole 43, the outer surfaces of the first pressing ribs 224 come into contact with the inner circumferential surface of the insertion hole 43 and are pressed inward, so that the upper housing 22U is held by the shell 4. Furthermore, since the upper housing 22U is made of an elastic insulating material, the cylindrical portion 221 is elastically deformable inward. Therefore, when the upper housing 22U is inserted into the insertion hole 43, the outer surfaces of the four first pressing ribs 224 are pressed inward by the inner circumferential surface of the insertion hole 43, and as a result, the portion of the cylindrical portion 221 on which the first pressing ribs 224 are formed is elastically deformed inward. This allows for stronger contact between the inner surface of the insertion hole 223 of the upper housing 22U and the horizontally extended portion 211 of the upper contact pin 21U, preventing the upper contact pin 21U from shifting within the insertion hole 223 and from detaching from the insertion hole 223.

[0037] Returning to Figures 8 and 9, the pair of second pressing ribs 225 are formed to prevent the upper contact pin 21U from shifting toward its base end or detaching from the insertion hole 223 of the upper housing 22U, and to prevent the cylindrical portion 221 from detaching from the insertion hole 43, when the cylindrical portion 221 of the upper housing 22U is inserted into the insertion hole 43 of the shell 4. The pair of second pressing ribs 225 are projections that extend linearly in the front-rear direction while being spaced apart from each other. The pair of second pressing ribs 225 face each other at an angular interval of 180 degrees via the pair of insertion holes 223. The pair of second pressing ribs 225 are formed on both sides (both sides in the X direction) of the cylindrical portion 221. As shown in Figure 8, each of the pair of second pressing ribs 225 is a stepped projection whose height increases in stages from the tip side to the base side, and the base side of each of the pair of second pressing ribs 225 is a high back portion that protrudes more in the X direction than the tip side.

[0038] The second pressing rib 225 is provided to contact the inner circumferential surface of the insertion hole 43 of the shell 4 when the upper housing 22U is held by the shell 4, thereby preventing the cylindrical portion 221 of the upper housing 22U from detaching from the insertion hole 43. Furthermore, in a natural state where no external force is applied to the upper housing 22U, the sum of the outer diameter of the cylindrical portion 221 in the width direction (X direction) and the height (protrusion amount) of the pair of second pressing ribs 225 is slightly larger than the inner diameter of the insertion hole 43 of the shell 4 in the width direction. With this configuration, when the cylindrical portion 221 is inserted into the insertion hole 43, the outer surface of the second pressing rib 225 contacts the inner circumferential surface of the insertion hole 43 and is pressed inward, thereby holding the upper housing 22U by the shell 4. Moreover, as described above, the cylindrical portion 221 is elastically deformable inward. Therefore, when the upper housing 22U is inserted into the insertion hole 43, the outer surface of the second pressing rib 225 comes into contact with the inner circumferential surface of the insertion hole 43 and is pressed inward, causing the portion of the cylindrical part 221 where the second pressing rib 225 is formed to elastically deform inward. This makes the inner surface of the insertion hole 223 of the upper housing 22U and the horizontally extended portion 211 of the upper contact pin 21U come into stronger contact, preventing the upper contact pin 21U from shifting within the insertion hole 223 and from detaching from the insertion hole 223.

[0039] The block portion 226 is a block-shaped portion formed on the lower surface of the cylindrical portion 221, projecting downward from above the base end adjacent to the downward extension portion 222. The tip surface of the block portion 226 is connected to the base ends of the two first pressing ribs 224 formed on the lower surface of the cylindrical portion 221. Furthermore, the base end surface of the block portion 226 is connected to the downward extension portion 222. The tip surface of the block portion 226 is a flat surface perpendicular to the front-rear direction, and the lower surface of the block portion 226 is a flat surface perpendicular to the height direction. Also, as shown in Figure 8, a recess 2261 is formed on the tip surface of the block portion 226 in the portion adjacent to the base ends of the two first pressing ribs 224, allowing elastic deformation (bending) of the lower end of the block portion 226 in the front-rear direction.

[0040] The engaging recess 227 is a rectangular recess formed on the lower surface of the block portion 226, opening downwards. The engaging recess 227 extends linearly in the width direction (X direction) on the lower surface of the block portion 226. Both ends of the engaging recess 227 in the width direction are not closed and are open to the outside. The width of the engaging recess 227 in the Z direction is approximately equal to the thickness of the shield member 3.

[0041] As shown in Figure 6, when the electrical connector 1 is assembled, the upper end of the shield member 3 is inserted into the engagement recess 227. In this state, the main body 31 of the shield member 3 contacts the inner surface on the front end and the inner surface on the base end of the engagement recess 227. As will be described later, the shield member 3 is press-fitted into the slit 49 (see Figure 14) of the shell 4 and fixed to the shell 4, so it does not move in the front-rear direction. Therefore, by inserting the shield member 3 into the engagement recess 227 and engaging the cylindrical portion 221 of the upper housing 22U with the shield member 3, the shift of the upper housing 22U toward the base end within the shell 4 can be reliably prevented. With this configuration, the shift of the upper receptacle assembly 2U within the shell 4 can be prevented, the position of the upper contact pin 21U within the shell 4 can be stabilized, and the contact reliability of the electrical connector 1 can be improved.

[0042] Returning to Figures 8 and 9, the downward extension portion 222 is the portion that houses the downward extension portion 212 of the upper contact pin 21U when the upper contact pin 21U is held by the upper housing 22U. The downward extension portion 222 includes a front plate 2221 that extends downward from the lower part of the base end of the cylindrical portion 221, a pair of side wall portions 2222 that extend from both ends in the width direction of the front plate 2221 toward the base end, and a central wall portion 2223 that is between the pair of side wall portions 2222 and extends toward the base end from the center in the width direction of the front plate 2221, while being spaced apart from the pair of side wall portions 2222.

[0043] The front plate 2221 is a plate-like portion that extends vertically downward from the lower portion of the base end of the cylindrical portion 221. The pair of side wall portions 2222 are plate-like portions that extend from both end portions in the width direction of the front plate 2221 toward the base end side. Two internal spaces for accommodating the respective downward extending portions 212 of the pair of upper contact pins 21U are defined by the base end surface of the front plate 2221, the inner surfaces of the pair of side wall portions 2222, and the outer surface of the central wall portion 2223. As shown in FIG. 6, when the pair of upper contact pins 21U are held by the upper housing 22U, the respective downward extending portions 212 of the pair of upper contact pins 21U are located in the two internal spaces of the downward extending portion 222, respectively.

[0044] Returning to FIG. 9, the central wall portion 2223 is a plate-like portion that extends from the center in the width direction of the front plate 2221 toward the base end side. The central wall portion 2223 is located between the pair of side wall portions 2222 and faces both of the pair of side wall portions 2222 with a gap therebetween. The central wall portion 2223 separates the two internal spaces described above. Further, since the separation distance in the X direction between the side wall portion 2222 and the central wall portion 2223 gradually decreases from the base end side to the tip end side, the internal space defined by the side wall portion 2222 and the central wall portion 2223 has a tapered shape with a wider opening width on the base end side. When inserting the horizontal extending portion 211 of the upper contact pin 21U into the insertion hole 223 of the upper housing 22U from the base end side, the downward extending portion 222 of the upper contact pin 21U slides on the inner surface of the side wall portion 2222 or the outer surface of the central wall portion 2223, and the insertion of the upper contact pin 21U is guided. Therefore, the insertion of the upper contact pin 21U into the upper housing 22U becomes easy.

[0045] Next, referring to FIG. 10, the two lower receptacle assemblies 2L will be described in detail. Since the two lower receptacle assemblies 2L have the same configuration as each other, one lower receptacle assembly 2L will be described in detail as a representative below. As shown in FIG. 10, the lower receptacle assembly 2L includes a pair of lower contact pins 21L that respectively contact the corresponding contact pins of the mating connector, and an insulating lower housing 22L that holds the pair of lower contact pins 21L.

[0046] Each of the pair of lower contact pins 21L has the same configuration as the upper contact pin 21U described above, except that the lengths of the horizontal extension portion 211 and the lower extension portion 212 are shorter. Therefore, the description of the upper contact pin 21U is also applied to each of the pair of lower contact pins 21L.

[0047] The lower housing 22L has the same configuration as the upper housing 22U described above, except that the lengths of the cylindrical portion 221 and the lower extension portion 222 are shorter, each of the pair of side wall portions 2222 includes a locking piece 228 and a locking projection 229, and the block portion 226 and the engaging recess 227 are omitted. Hereinafter, the differences between the lower housing 22L and the upper housing 22U will be described in detail, and the description of the common points between the lower housing 22L and the upper housing 22U will be omitted.

[0048] As shown in FIGS. 10 and 11, each of the pair of side wall portions 2222 of the lower extension portion 222 of the lower housing 22L has an elastically deformable locking piece 228 and a locking projection 229 that extends outward from the base end side edge portion of the outer surface of the locking piece 228. The locking piece 228 extends from both ends in the width direction of the front plate 2221 toward the base end side and is a plate-like portion that can be elastically deformed inward and outward. The base end portion of the locking piece 228 is a flat surface orthogonal to the front-rear direction. Each of the upper end portion and the lower end portion of the locking piece 228 is separated from the upper portion and the lower portion (the portion other than the locking piece 228) of the side wall portion 2222 by a notch. Thereby, the elasticity of the locking piece 228 in the inner and outer (X direction) directions is provided.

[0049] As shown in FIG. 12, the locking projection 229 has a function of contacting the inner surface of the main body portion 41 of the shell 4 when the lower receptacle assembly 2L is held inside the shell 4 and preventing the lower receptacle assembly 2L from shifting toward the base end side inside the shell 4.

[0050] Returning to Figures 10 and 11, the locking projection 229 is a tapered portion that protrudes outward from the base end edge of the outer surface of the locking piece 228. The tip surface of the locking projection 229 is an inclined surface that slopes outward from the tip side to the base end side. The outer surface (the surface facing outward) of the inclined surface of the locking projection 229 that extends from the base end side to the base end side is a flat surface perpendicular to the width direction. The base end surface of the locking projection 229 is a flat surface perpendicular to the front-rear direction and is continuous with the flat surface of the base end of the locking piece 228. When inserting the lower receptacle assembly 2L into the shell 4, the inclined surface on the tip side of the locking projection 229 slides forward towards the tip while sliding on the inclined surface formed at the base end of the stopper portion 48 (see Figure 14) of the shell 4, which will be described later. As shown in Figure 12, with the lower receptacle assembly 2L held inside the shell 4, the outer surface of the locking projection 229 is in contact with the inner surface of the main body portion 41 of the shell 4 (the inner surface of the side wall 412 or the side surface of the central wall portion 414). The base end surface of the locking projection 229 faces the tip surface of the stopper portion 48 with a gap in between.

[0051] Returning to Figure 7, each of the two shielding members 3 is press-fitted into the slits 49 of the shell 4 from below, and has the function of preventing electromagnetic interference between adjacent lower contact pins 21L and upper contact pins 21U in the front-rear direction. The two shielding members 3 are arranged in parallel in the width direction while held in the two slits 49 of the shell 4 (see Figure 12). Each of the two shielding members 3 can improve the signal transmission characteristics of the electrical connector 1 by preventing electromagnetic interference between adjacent lower contact pins 21L and upper contact pins 21U in the front-rear direction.

[0052] As shown in Figure 5, the shield member 3 is a plate-shaped member made of a metal material, which is press-fitted into the slit 49 of the shell 4 and held by the shell 4 so as to be positioned between the downward extension 212 of the lower contact pin 21L and the downward extension 212 of the upper contact pin 21U. As shown in Figure 7, the shield member 3 comprises a plate-shaped main body portion 31 and two pairs of press-fit protrusions 32 formed on the main body portion 31.

[0053] The main body portion 31 is a plate-shaped portion extending in the XY plane. As shown in Figure 6, when the shield member 3 is press-fitted into the slit 49 of the shell 4, the upper end of the main body portion 31 is inserted into the engagement recess 227 of the lower housing 22L. At this time, the upper end of the main body portion 31 contacts and engages with the inner surface on the tip side and the inner surface on the base side of the engagement recess 227, thereby engaging the shield member 3 with the cylindrical portion 221 of the upper housing 22U. This engagement prevents the upper receptacle assembly 2U from shifting inside the shell 4, stabilizes the position of the upper contact pin 21U inside the shell 4, and improves the contact reliability of the electrical connector 1.

[0054] Two pairs of press-fit protrusions 32 are formed at both ends of the main body portion 31 in the width direction. Each pair of press-fit protrusions 32 is formed side by side in the height direction. One of the pair of press-fit protrusions 32 that are side by side in the height direction protrudes toward the tip, and the other protrudes toward the base. Specifically, of the pair of press-fit protrusions 32 formed at the +X direction end of the main body portion 31, the lower press-fit protrusion 32 protrudes toward the base, and the upper press-fit protrusion 32 protrudes toward the tip. Of the pair of press-fit protrusions 32 formed at the -X direction end of the main body portion 31, the lower press-fit protrusion 32 protrudes toward the tip, and the upper press-fit protrusion 32 protrudes toward the base. By press-fitting the shield member 3 into the slit 49 of the shell 4, the two pairs of press-fit protrusions 32 come into contact with the slit 49 of the shell 4. This configuration prevents the shield member 3 from coming out of the slit 49.

[0055] Returning to Figure 7, the shell 4 functions as a housing for containing each component of the electrical connector 1, and as an electrical path that electrically connects the electrical connector 1 to the terminals provided in the boss holes (terminal holes) 110 on the circuit board 100 on which the electrical connector 1 is mounted. As shown in Figures 13 and 14, the shell 4 is a box-shaped member made of a metal material.

[0056] The shell 4 comprises a main body 41 consisting of a front plate 411, a pair of side walls 412, a top plate 413, and a central wall portion 414; four cylindrical portions 42 extending from the front end surface of the front plate 411 toward the front end of the main body 41; four through holes 43 for inserting the upper housing 22U or the lower housing 22L; four ground terminals 44 extending downward from the lower end of the main body 41; a pair of wall portions 45 formed on each of the pair of side walls 412 of the main body 41 so as to extend in the Z direction spaced apart from each other; a cover receiving portion 46 formed on the outer surface of each of the pair of side walls 412; four fitting recesses 47 formed on the front end surface of the front plate 411; four stopper portions 48 protruding from the inner surfaces of the pair of side walls 412 and both sides of the central wall portion 414, respectively; and two slits 49 formed on the lower surface of the main body 41.

[0057] The main body 41 includes a plate-shaped front plate 411 perpendicular to the insertion / removal direction of the mating connector, a pair of side walls 412 extending from both ends of the front plate 411 in the width direction toward the base end, a top plate 413 extending from the upper end of the front plate 411 toward the base end, and a central wall portion 414 located between the pair of side walls 412, and has a box-like shape that is open toward the base end and downward. Furthermore, two storage spaces are formed by the inner surfaces of the pair of side walls 412 and both sides of the central wall portion 414. A pair of lower receptacle assemblies 2L and upper receptacle assemblies 2U are housed in one storage space. As shown in Figure 6, within the storage space, the horizontal extension portion 211 of the upper housing 22U is located above the horizontal extension portion 211 of the lower housing 22L, and furthermore, the downward extension portion 212 of the upper housing 22U is located closer to the base end than the downward extension portion 212 of the lower housing 22L.

[0058] Returning to Figures 13 and 14, the four cylindrical portions 42 are cylindrical members formed to protrude from the front surface of the front plate 411 of the main body portion 41 toward the front end, forming a 2x2 matrix. The cylindrical portions 42 function as external conductors that cover the cylindrical portions 221 of the upper housing 22U or the lower housing 22L from the outside. When the mating connector is connected to the electrical connector 1, the cylindrical portions 42 each contact the corresponding outer contacts of the mating connector, making the ground potential of the electrical connector 1 and the mating connector equal.

[0059] The four through holes 43 are elliptical through-holes formed to extend linearly in the front-rear direction, into which the cylindrical portion 221 of the upper housing 22U or the lower housing 22L is inserted. Each of the two upper through holes 43 is formed to penetrate the main body 41 and the upper cylindrical portion 42 in the front-rear direction. Inside the main body 41, the lower sides of the two upper through holes 43 are cut out and open downwards. Each of the two lower through holes 43 is formed to penetrate the lower cylindrical portion 42 in the front-rear direction. The width of the inner diameter of each through hole 43 (length in the X direction) is greater than the height of the inner diameter of the through hole 43 (length in the Y direction), corresponding to the rounded rectangular planar shape of the cylindrical portion 221 of the upper housing 22U or the lower housing 22L.

[0060] As shown in Figure 6, when the cylindrical portion 221 of the upper housing 22U or the lower housing 22L is inserted into the through hole 43, the inner circumferential surface of the through hole 43 contacts the outer surfaces of the four first pressing ribs 224 of the upper housing 22U or the lower housing 22L. As a result, the outer surfaces of the four first pressing ribs 224 are pressed inward, and the portion of the cylindrical portion 221 where the first pressing ribs 224 are formed is elastically deformed inward. Furthermore, when the cylindrical portion 221 of the upper housing 22U or the lower housing 22L is inserted into the through hole 43, the inner circumferential surface of the through hole 43 presses the outer surfaces of the pair of second pressing ribs 225 of the upper housing 22U or the lower housing 22L inward, and the portion of the cylindrical portion 221 where the pair of second pressing ribs 225 are formed is elastically deformed inward. This elastic deformation of the cylindrical portion 221 inward allows the upper contact pin 21U or the lower contact pin 21L to be locked into the insertion hole 223 of the upper housing 22U or the lower housing 22L.

[0061] Returning to Figures 13 and 14, the four ground terminals 44 are inserted into boss holes 110 formed in the circuit board 100 on which the electrical connector 1 is mounted during the reflow process described later. Then, hot air is applied to the electrical connector 1 and the circuit board 100 to melt the solder paste filled in the boss holes 110, thereby joining the four ground terminals 44 to the terminals provided in the four boss holes 110 (see Figure 3). Since the ground terminals 44 are fixed in the boss holes 110 of the circuit board 100, the electrical connector 1 is mechanically held on the circuit board 100. Furthermore, the shell 4 is electrically connected to the terminals provided in the boss holes 110 of the circuit board 100 via the ground terminals 44, so that the ground potential of the electrical connector 1 and the ground potential of the circuit board 100 are equal.

[0062] The pair of wall portions 45 are provided on the pair of side walls 412 of the main body portion 41 to form a pair of cover receiving portions 46 for receiving a pair of protruding pieces 54 (see Figure 15) of the cover 5. One of the pair of wall portions 45 is formed on the upper side (+Y direction) of each of the pair of side walls 412, and the other is formed on the lower side (-Y direction) of each of the pair of side walls 412, and they face each other via the cover receiving portions 46.

[0063] Each of the pair of cover receiving portions 46 is formed on the outer surfaces of the pair of side walls 412 of the main body portion 41, between the pair of wall portions 45. The pair of cover receiving portions 46 each have the function of receiving the pair of protruding pieces 54 of the cover 5. The cover receiving portion 46 is defined by the outer surfaces of the side walls 412 of the main body portion 41 and the inner surfaces of the pair of wall portions 45. The cover receiving portion 46 includes a flat portion 461 which is a flat surface perpendicular to the width direction, and an engaging wall 462 formed on the flat portion 461 and extending in the height direction within the cover receiving portion 46.

[0064] The flat portion 461 is a flat surface that extends from the tip to the base of the side wall 412 on the YZ plane. As shown in Figure 20, when the cover 5 is attached to the shell 4, the outer surface of the flat portion 461 faces the inner surfaces of the pair of protruding pieces 54 of the cover 5 with a gap in between. Furthermore, a portion of the outer surface of the flat portion 461 is exposed to the outside through a second through hole 58 formed in each of the pair of protruding pieces 54 of the cover 5, which will be described later.

[0065] Returning to Figures 13 and 14, the engaging wall 462 extends linearly in the height direction on the flat portion 461 and is a projection that protrudes outward from the flat portion 461 at a constant height. The engaging wall 462 is formed to engage with the engaging projection 55 of the cover 5, which will be described later, and to attach the cover 5 to the shell 4. The engaging wall 462 connects the inner surfaces (inner surfaces in the Y direction) of the pair of wall portions 45. The tip surface of the engaging wall 462 is an inclined surface, and the base end surface of the engaging wall 462 is a flat surface perpendicular to the front-rear direction.

[0066] The four fitting recesses 47 are rectangular recesses formed on the front surface of the front plate 411 of the main body 41. The four fitting recesses 47 are formed to position the cover 5 relative to the shell 4 by fitting with the four fitting projections 56 (see Figure 16) of the cover 5. The four fitting recesses 47 are formed at the upper end, lower end, and both ends in the width direction of the front plate 411. The fitting recess 47 at the upper end of the front plate 411 extends linearly downward from the center in the width direction of the upper end of the front plate 411 between the two upper cylindrical parts 42. The fitting recess 47 at the upper end is formed to open forward and upward. The fitting recess 47 at the lower end of the front plate 411 extends linearly upward from the center in the width direction of the lower end of the front plate 411 between the two lower cylindrical parts 42. The fitting recess 47 at the lower end is formed to open forward and downward. The fitting recesses 47 at both ends in the X direction are formed at the center in the height direction of both ends of the front plate 411, and are located between the upper cylindrical portion 42 and the lower cylindrical portion 42 which are parallel in the height direction. Each of the fitting recesses 47 at both ends opens outward in the forward and width directions. The four fitting recesses 47 are formed by cutting out the front end surface of the front plate 411 toward the base end, in a position and shape corresponding to the four fitting projections 56 of the cover 5, which will be described later. By inserting the four fitting projections 56 into the four fitting recesses 47, the cover 5 is positioned relative to the shell 4. Furthermore, the fitting of the four fitting recesses 47 and the four fitting projections 56 prevents the cover 5 from shifting in the width direction and height direction, and stabilizes the position of the cover 5 relative to the shell 4.

[0067] As shown in Figure 14, the four stopper portions 48 are projections that protrude inward from the inner surfaces of the pair of side walls 412 and from both sides of the central wall portion 414, from locations facing the pair of side walls 2222 of the downward extension portion 222 of the lower housing 22L. As shown in Figure 12, each stopper portion 48 is formed at a location closer to the base end than the locking piece 228 and locking projection 229 of the downward extension portion 222 of the lower housing 22L when the lower housing 22L is housed in the shell 4. The stopper portion 48 has a tapered shape in which the width in the front-rear direction (Z direction) gradually decreases as it moves away from the inner surface of the side wall 412 or the side of the central wall portion 414. The tip surface of the stopper portion 48 is a flat surface perpendicular to the front-rear direction. The base end surface of the stopper portion 48 is an inclined surface that slopes outward from the tip side to the base end side. Furthermore, when the lower housing 22L is housed within the shell 4, the stopper portion 48 is spaced apart from the locking piece 228 and the locking projection 229 of the downward extension portion 222 of the lower housing 22L. The tip surface of the stopper portion 48 faces the base end surface of the locking piece 228 and the base end surface of the locking projection 229 with a gap in between.

[0068] As the cylindrical portion 221 of the lower housing 22L is inserted into the cylindrical portion 42 of the shell 4, the tip surface of the locking projection 229 of the downward extension portion 222 of the lower housing 22L slides on the inclined surface which is the base end surface of the stopper portion 48. As the downward extension portion 222 advances toward the tip, the locking pieces 228 of each of the pair of side wall portions 2222 of the downward extension portion 222 gradually elastically deform inward. When the base end surface of the locking projection 229 exceeds the tip surface of the stopper portion 48, the locking pieces 228 elastically return to their outward position, and the side surface located on the outside of the locking projection 229 comes into contact with the inner surface of the main body portion 41 of the shell 4. The locking projection 229 is pressed against the inner surface of the main body portion 41 of the shell 4 by the elastic restoring force of the locking piece 228, thereby improving the holding force of the lower housing 22L inside the shell 4 and effectively preventing the lower housing 22L from shifting towards the base end inside the shell 4.

[0069] Returning to Figure 14, the two slits 49 are portions for press-fitting the two shield members 3, respectively. The two slits 49 are formed on the inner surfaces of the pair of side walls 412 and on both sides of the central wall 414, extending upward from the lower surface of the main body 41. The slits 49 are positioned such that when the shield members 3 are press-fitted into the slits 49, the shield members 3 are located between the downward extension portion 222 of the upper housing 22U and the downward extension portion 222 of the lower housing 22L. The slits 49 are also divided into left and right sections by the storage space of the main body 41.

[0070] Returning to Figure 7, the cover 5 is attached to the front end portion of the shell 4 and has the function of guiding the connection between the electrical connector 1 and the mating connector. As shown in Figures 15 and 16, the cover 5 comprises a bottom plate 51 facing the main body portion 41 of the shell 4 from the front end, a rectangular cylindrical portion 52, four through holes 53 formed in the bottom plate 51, a pair of protruding pieces 54 extending from the bottom plate 51 toward the base end, two pairs of engaging protrusions 55 extending inward from the base end edge of the inner surface of each of the pair of protruding pieces 54, four fitting protrusions 56 protruding toward the base end from the base end surface of the bottom plate 51, a first through hole 57 formed in the bottom plate 51, and a second through hole 58 formed in each of the pair of protruding pieces 54.

[0071] The base plate 51 is a plate-shaped portion extending in the XY plane. When the cover 5 is attached to the shell 4, the base end surface of the base plate 51 faces the front end surface of the front plate 411 of the main body portion 41 of the shell 4 (see Figure 6). The cylindrical portion 52 is a rectangular cylindrical member that extends linearly from the front end surface of the base plate 51 toward the front end. The front end of the cylindrical portion 52 is open, and the connection between the electrical connector 1 and the mating connector is guided by inserting the mating connector into the opening at the front end of the cylindrical portion 52. The four insertion holes 53 are formed in the base plate 51 so as to penetrate in the insertion / removal direction (Z direction) of the mating connector, and are holes through which the cylindrical portion 42 of the shell 4 is inserted from the base end side. The four insertion holes 53 are formed to allow each of the four cylindrical portions 42 of the shell 4 to be inserted. The cover 5 is attached to the front end of the shell 4 from the front end so that the corresponding cylindrical portion 42 is inserted into each of the four insertion holes 53.

[0072] The pair of protruding pieces 54 are plate-like portions that extend from both ends in the width direction toward the base end of the base end surface of the bottom plate 51. The pair of protruding pieces 54 face each other with a gap between them. Each of the pair of protruding pieces 54 has a shape corresponding to each of the pair of cover receiving portions 46 of the shell 4 described above, and when the cover 5 is attached to the shell 4, the pair of protruding pieces 54 are housed within the pair of cover receiving portions 46. As shown in Figure 20, when the cover 5 is attached to the shell 4, the inner surfaces of each of the pair of protruding pieces 54 of the cover 5 face the outer surfaces of the respective flat portions 461 of the pair of cover receiving portions 46 of the shell 4 with a gap between them.

[0073] Returning to Figure 16, each pair of the two pairs of engaging projections 55 is formed to engage with the corresponding engaging wall 462 of the shell 4 and to perform the attachment of the cover 5 to the shell 4. A pair of engaging projections 55 is formed on each protruding piece 54. Each of the pair of engaging projections 55 is a tapered portion that protrudes inward from the base end edge of the inner surface of the protruding piece 54. The base end surface of each engaging projection 55 is an inclined surface, and the tip surface of each engaging projection 55 is a flat surface perpendicular to the front-rear direction.

[0074] Referring to Figure 20, the attachment of the cover 5 to the shell 4 will be described in detail. When attaching the cover 5 to the shell 4, a pair of protruding pieces 54 of the cover 5 are inserted into a pair of cover receiving portions 46 of the shell 4. When the cover 5 is pressed against the shell 4 in this state, a pair of engaging projections 55 of the protruding pieces 54 slide along the leading edge surface of the corresponding engaging wall 462 of the shell 4, and the pair of protruding pieces 54 open outwards. Once the pair of engaging projections 55 of the cover 5 have overcome the corresponding engaging wall 462, the pair of protruding pieces 54 elastically return inwards, and the pair of engaging projections 55 engage with the corresponding engaging wall 462. The cover 5 is fixed to the shell 4 by this snap-fit. When the cover 5 is attached to the shell 4, the inner surfaces of the pair of protruding pieces 54 of the cover 5 face the outer surfaces (flat portions 461) of the pair of side walls 412 of the shell 4 with a gap between them. This gap communicates with the outside through the second through hole 58.

[0075] Returning to Figure 16, the four fitting projections 56 are formed to protrude from the base end surface of the bottom plate 51 toward the base end. The four fitting projections 56 are provided to fit into the four fitting recesses 47 of the shell 4 and to position the cover 5 relative to the shell 4. Each of the four fitting projections 56 is formed in a position and shape (rectangular prism shape) corresponding to each of the four fitting recesses 47, and the positioning of the cover 5 relative to the shell 4 is achieved by inserting each of the four fitting projections 56 into the four fitting recesses 47. The upper fitting projections 56 are located between the two upper insertion holes 53 and above the first through hole 57. The lower fitting projections 56 are located between the two lower insertion holes 53 and below the first through hole 57. Each of the fitting projections 56 on both sides in the X direction is located between the upper fitting projection 56 and the lower fitting projection 56, which are formed vertically in the height direction, and its outer surface is in contact with the inner surface of the adjacent projection 54.

[0076] As shown in Figure 18, when the cover 5 is attached to the shell 4, the upper fitting projection 56 is housed in a fitting recess 47 formed in the upper end of the front plate 411 of the shell 4. The other three fitting projections 56 (the lower and the fitting projections 56 on both sides in the X direction) are similarly housed in their respective fitting recesses 47 (the fitting recesses 47 at both ends in the lower and X directions). This structure prevents the cover 5 from shifting in the left-right and up-down directions, and stabilizes the position of the cover 5 relative to the shell 4.

[0077] Returning to Figure 16, each of the upper and lower fitting projections 56 has a projection 561 that protrudes from the base end surface toward the base end. The projection 561 is a conical projection whose diameter gradually decreases from the tip end toward the base end. When the cover 5 is attached to the shell 4, the projection 561 is in contact with the bottom surface (base end surface) of the fitting recess 47 of the shell 4 and is sandwiched between the bottom surface of the fitting recess 47 and the base end surface of the fitting projection 56.

[0078] Returning to Figure 15, the first through-hole 57 is a circular hole that penetrates the bottom plate 51 in the front-to-back direction (the direction in which the mating connector is inserted and removed). The first through-hole 57 is formed to expose the front plate 411 (the tip surface of the main body 41) of the shell 4 to the outside. The first through-hole 57 is formed approximately at the center of the bottom plate 51 in the width and height directions. Furthermore, the first through-hole 57 is formed in the bottom plate 51 so as to be spaced apart from the four insertion holes 53 and not in communication with the four insertion holes 53.

[0079] Figures 17 and 18 show the cover 5 attached to the shell 4. For the sake of simplicity, only the cover 5 and shell 4 are shown in Figures 17 and 18, and other components are omitted. As shown in Figure 17, with the cover 5 attached to the shell 4, the front end surface of the front plate 411 of the shell 4 (the front end surface of the main body 41) is exposed to the outside through the first through hole 57. As a result, the exposed area of ​​the shell 4 to the outside increases, and the surface area of ​​the shell 4 that is hit by the hot air W1 (see Figure 20) in the reflow process described later increases. This improves the efficiency of the rise in the surface temperature of the shell 4, and the rise in the surface temperature of the shell 4 proceeds more effectively and uniformly. As a result, the electrical connector 1 can be mounted on the circuit board 100 in a reflow process with lower temperature hot air, preventing expansion, deformation, or damage due to overheating of the electrical connector 1 and the circuit board 100, and improving the contact reliability of the electrical connector 1. Furthermore, since the reflow process uses lower temperature hot air, it becomes possible to mount the electrical connector 1 onto the circuit board 100, thus reducing the energy cost of the reflow process.

[0080] The number and shape of the first through-holes 57 are not limited to a single circular hole as shown in the figure, and are not particularly limited as long as the front end surface of the front plate 411 of the shell 4 (the front end surface of the main body 41) can be exposed to the outside. The shape of the first through-holes 57 may be elliptical, polygonal, irregular, etc., and the number of first through-holes 57 may be two or more, depending on the required exposed area of ​​the main body 41 of the shell 4.

[0081] Returning to Figure 16, the pair of second through-holes 58 are circular holes that penetrate the pair of protruding pieces 54 of the cover 5 in a width direction perpendicular to the insertion / removal direction of the mating connector. The pair of second through-holes 58 are formed to expose the pair of side walls 412 of the shell 4 to the outside. As shown in Figure 18, when the cover 5 is attached to the shell 4, the flat portions 461 of the outer surfaces of the pair of side walls 412 of the shell 4 are exposed to the outside through the second through-holes 58. As a result, as shown in Figure 20, the area of ​​the outer surfaces of the pair of side walls 412 of the shell 4 that are exposed to the outside increases, and therefore the surface area of ​​the shell 4 that is directly hit by the hot air W2 in the reflow process described later increases.

[0082] Furthermore, the inner surfaces of the pair of protruding pieces 54 of the cover 5 and the outer surfaces (flat portions 461) of the pair of side walls 412 of the shell 4 face each other with a gap in between. The gap between the protruding pieces 54 of the cover 5 and the flat portions 461 of the shell 4 is in communication with the outside through a second through hole 58. Therefore, in the reflow process, hot air W2 flows from the outside into the gap between the inner surfaces of the pair of protruding pieces 54 and the outer surfaces of the pair of side walls 412 through the pair of second through holes 58. As a result, even the portions of the pair of side walls 412 that are covered by the cover 5 are hit by the hot air W2, so the surface area of ​​the shell 4 that is directly hit by the hot air W2 is further increased. This further improves the efficiency of the surface temperature rise of the shell 4, and the surface temperature rise of the shell 4 proceeds more effectively and uniformly.

[0083] In the figure, one second through-hole 58 is formed in each protruding piece 54, and the shape of the second through-hole 58 is circular. However, the number and shape of the second through-hole 58 are not limited to this, and are not particularly limited as long as the outer surfaces of the pair of side walls 412 of the main body portion 41 of the shell 4 can be exposed to the outside. The shape of the second through-hole 58 may be elliptical, polygonal, irregular, etc., and the number of second through-holes 58 may be two or more, depending on the required exposed area of ​​the main body portion 41 of the shell 4. Also, in the figure, the second through-hole 58 is formed in both of the pair of protruding pieces 54, but this is not limited to this, and it is sufficient if the second through-hole 58 is formed in at least one of the protruding pieces 54.

[0084] Figures 19(A) to (D) show modified examples of the second through-hole 58. For example, in the modified example of the second through-hole 58 shown in Figure 19(A), one horizontally elongated D-shaped second through-hole 58 is formed in the protruding piece 54. In the modified example of the second through-hole 58 shown in Figure 19(B), three elongated rectangular second through-holes 58 extending along the Z direction are formed in the protruding piece 54 and are arranged parallel to the height direction. In the modified example of the second through-hole 58 shown in Figure 19(C), six elongated rectangular second through-holes 58 extending along the Z direction are formed in the protruding piece 54 and are arranged in a matrix of three vertically and two horizontally. In the modified form of the second through-hole 58 shown in Figure 19(D), four triangular second through-holes 58 are formed in the protruding piece 54, with three second through-holes 58 arranged alternately at the tip end (the two upper and lower ones with the triangular vertices facing the base end, and the central one with the triangular vertices facing the tip end), and furthermore, one second through-hole 58 is positioned with the triangular vertices facing the base end towards the central of the three second through-holes 58 at the tip end. Embodiments using the modified forms of the second through-hole 58 shown in Figures 19(A) to (D), respectively, are also within the scope of the present invention.

[0085] Next, the method for mounting the electrical connector 1 onto the circuit board 100 will be described in detail. In order to mount the electrical connector 1 onto the circuit board 100, a reflow process is performed. The circuit board 100 is provided with four boss holes 110 for inserting the four ground terminals 44 of the shell 4, and eight terminals 120 for inserting the eight terminal portions 214 of the contact pins 21U and 21L, respectively (see Figure 3). The four boss holes 110 and the eight terminals 120 are terminal holes formed on the circuit board 100. The four boss holes 110 and the eight terminals 120 are provided to establish an electrical connection between the electrical connector 1 and the circuit board 100. Solder paste is pre-filled into the four boss holes 110 and the eight terminals 120.

[0086] In the reflow process, first, the four ground terminals 44 of the shell 4 are inserted into the four boss holes 110, and the eight terminal portions 214 of the contact pins 21U and 21L are inserted into the eight terminals 120. Then, hot air is applied to the electrical connector 1 and the circuit board 100 to perform soldering between the four ground terminals 44 and the terminals provided in the four boss holes 110, and between the eight terminal portions 214 of the contact pins 21U and 21L and the eight terminals 120. By applying hot air to the electrical connector 1 in this way, the surface temperature of the metal shell 4 rises, and the solder in the boss holes 110 and terminals 120 melts. As a result, the four ground terminals 44 and the terminals provided in the four boss holes 110, and the eight terminal portions 214 and the eight terminals 120 are connected, respectively. This establishes an electrical connection between the electrical connector 1 and the circuit board 100.

[0087] In the reflow process, heaters and fans (not shown) are installed above and below the circuit board 100 and the electrical connector 1 to generate hot air, and hot air is blown onto the electrical connector 1 from all directions (front, back, left, right, up, and down). Arrows W1 and W2 in Figure 20 typically show a portion of the hot air flow in the reflow process. Arrow W1 shows a portion of the hot air hitting the electrical connector 1 from the front, and arrow W2 shows a portion of the hot air hitting the electrical connector 1 from the left and right.

[0088] As described above, a first through-hole 57 is formed in the bottom plate 51 of the cover 5 so as to penetrate in the front-to-back direction, and the leading edge surface of the front plate 411 of the shell 4 is exposed to the outside through the first through-hole 57. Therefore, in the reflow process, the hot air W1 directly hits the leading edge surface of the front plate 411 that is exposed through the first through-hole 57. In this way, the area of ​​the shell 4 exposed to the outside increases, and the area directly hit by the hot air W1 increases. As a result, the efficiency of raising the surface temperature of the shell 4 is improved.

[0089] Furthermore, each of the pair of protruding pieces 54 of the cover 5 has a second through-hole 58 formed therein, penetrating in a width direction perpendicular to the insertion / removal direction of the mating side. The flat portion 461 of the cover receiving portion 46 formed on the outer surface of each of the pair of side walls 412 of the shell 4 is exposed to the outside through the second through-hole 58. In this way, the area of ​​the shell 4 exposed to the outside is increased, and the surface area of ​​the shell 4 that is directly hit by the hot air W2 is increased. As a result, the efficiency of raising the surface temperature of the shell 4 is improved.

[0090] Furthermore, as described above, when the cover 5 is attached to the shell 4, the inner surfaces of the pair of protruding pieces 54 face the outer surfaces (flat portions 461) of the pair of side walls 412 with a gap between them. A second through hole 58 is formed in each of the pair of protruding pieces 54, and the gap between the inner surfaces of the protruding pieces 54 of the cover 5 and the flat portions 461 of the shell 4 communicates with the outside through the second through hole 58. Therefore, the hot air W2 flows into the gap between the protruding pieces 54 and the side walls 412 through the second through hole 58, and the hot air W2 directly hits the outer surface of the side wall 412 facing the gap. As a result, the hot air W2 also hits the outer surface of the side wall 412 that is covered by the protruding pieces 54 and not exposed to the outside, further increasing the surface area of ​​the shell 4 that is directly hit by the hot air W2. This allows the surface temperature of the shell 4 to rise even more efficiently.

[0091] As described above, a first through-hole 57 is formed in the bottom plate 51 of the cover 5, and a second through-hole 58 is formed in the protruding piece 54 of the cover 5. Therefore, the front end surface of the front plate 411 of the shell 4 (the front end surface of the main body 41) is exposed to the outside through the first through-hole 57, and furthermore, the flat portion 461 of the side wall 412 of the shell 4 is exposed to the outside through the second through-hole 58. As a result, the area in which the hot air W1 and hot air W2 directly contact the shell 4 increases during the reflow process, so that the surface temperature of the shell 4 rises effectively and uniformly. As a result, the temperature rise efficiency of the shell 4 surface temperature is improved, so that the surface temperature of the shell 4 can be raised to the desired temperature within a predetermined time even when using lower temperature hot air. In this way, by making it possible to mount the electrical connector 1 to the circuit board 100 in a reflow process using lower temperature hot air, overheating of the electrical connector 1 and the circuit board 100 can be prevented, and expansion, deformation, and damage can be prevented. As a result, the contact stability of the electrical connector 1 can be improved. Furthermore, since the reflow process uses hot air at a lower temperature than conventional methods, it becomes possible to mount the electrical connector 1 onto the circuit board 100, thereby reducing energy costs in the reflow process.

[0092] As described above, in the electrical connector 1 of the present invention, the cover 5 is provided with a first through hole 57 and a second through hole 58, and the main body portion 41 of the shell 4 is exposed to the outside through the first through hole 57 and the second through hole 58. As a result, the surface area of ​​the shell 4 that is directly hit by the hot air W1 and W2 during the reflow process increases, improving the efficiency of the rise in the surface temperature of the shell 4, and allowing the rise in the surface temperature of the shell 4 to proceed more effectively and uniformly. As a result, it becomes possible to mount the electrical connector 1 to the circuit board 100 in a reflow process with lower temperature hot air, preventing expansion, deformation, or damage due to overheating of the electrical connector 1 and the circuit board 100, and improving the contact reliability of the electrical connector 1. Furthermore, since it becomes possible to mount the electrical connector 1 to the circuit board 100 in a reflow process with lower temperature hot air, the energy cost of the reflow process can be reduced.

[0093] Although the electrical connector of the present invention has been described above based on the illustrated embodiment, the present invention is not limited thereto. Each component of the present invention can be replaced with any component that can perform a similar function, or any component can be added to each component of the present invention.

[0094] Those skilled in the art and the field to which the present invention pertains will be able to modify the configuration of the electrical connector of the present invention as described without significantly departing from the principles, concepts, and scope of the present invention, and the electrical connector having the modified configuration will also be within the scope of the present invention.

[0095] Furthermore, the number and types of electrical connector components shown in Figures 3 to 20 are merely illustrative examples, and the present invention is not necessarily limited thereto. Embodiments in which any components are added or combined, or any components are removed, are also within the scope of the present invention, without departing from the principles and intent of the present invention.

[0096] In the electrical connector of the present invention, since the shell is exposed to the outside through a through hole formed in the cover, the surface area exposed to the outside of the shell is increased, and the surface area exposed to hot air during the reflow process is increased. As a result, the efficiency of raising the surface temperature of the shell is improved, and the rise in the surface temperature of the shell proceeds more effectively and uniformly. Consequently, the reflow process can be performed with lower temperature hot air, which prevents expansion, deformation, or damage due to overheating of the electrical connector and circuit board, and improves the contact reliability of the electrical connector. Furthermore, since the reflow process can be performed with lower temperature hot air, the energy cost of the reflow process can be reduced. Therefore, the present invention has industrial applicability.

Claims

1. An electrical connector that can be connected to a mating connector inserted from the tip side, comprising: a receptacle assembly comprising: contact pins and an insulating housing that houses the contact pins inside; a metal shell that holds the receptacle assembly; and a cover attached to the shell to guide the connection of the mating connector to the electrical connector, wherein the shell comprises: a box-shaped body portion and a cylindrical portion extending from the body portion toward the tip side into which the receptacle assembly is inserted; and the cover comprises: a bottom plate facing the body portion of the shell from the tip side; a cylindrical portion extending from the bottom plate toward the tip side; an insertion hole formed in the bottom plate so as to penetrate in the insertion / removal direction of the mating connector, through which the cylindrical portion of the shell is inserted; and a through hole formed to expose the body portion of the shell to the outside.

2. The electrical connector according to claim 1, wherein the through hole of the cover is formed in the bottom plate so as to penetrate the insertion and removal direction of the mating connector, and the front surface of the main body of the shell is exposed to the outside through the through hole.

3. The electrical connector according to claim 2, wherein the through hole of the cover is spaced apart from the insertion hole and formed in the bottom plate so as not to communicate with the insertion hole.

4. The electrical connector according to claim 1, wherein the cover further comprises a protruding piece extending toward the base end from the bottom plate of the cover, the through hole of the cover is formed in the protruding piece of the cover so as to penetrate through in a width direction perpendicular to the insertion / removal direction of the mating connector, the main body of the shell includes a front plate perpendicular to the insertion / removal direction of the mating connector, and a side wall extending toward the base end from the width end of the front plate, and the side wall of the main body of the shell is exposed to the outside through the through hole of the cover.

5. The electrical connector according to claim 4, wherein the outer surface of the side wall of the main body of the shell has a flat portion perpendicular to the width direction and an engaging wall protruding outward from the flat portion, and the flat portion of the outer surface of the side wall is exposed to the outside through the through hole of the cover.

6. The electrical connector according to claim 5, wherein a gap exists between the protruding piece of the cover and the flat portion of the shell, and the gap communicates with the outside through the through hole.

7. The electrical connector according to claim 1, wherein the electrical connector is mounted on a circuit board, the shell has a ground terminal extending downward from the main body of the shell, and the ground terminal of the shell is connected to a corresponding boss hole of the circuit board by soldering.

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