TW202013823A - Electrical connector - Google Patents

Abstract

The present invention relates to an electrical connector comprising an insulative housing and a plurality of power contact pairs. The insulative housing includes a mounting portion for installing on a printed circuit board, a tongue portion extending forwardly from the mounting portion and a plurality of contact-receiving slots extending along a front-and-back direction. The power contact pairs are received in the relative contact-receiving slots and divided into at least two rows arranged in a height direction, and each power contact pair in each row includes two power contacts, each power contact defines a retaining portion held in the corresponding contact-receiving slot, a plurality of contacting portions extending forwardly from a front end of the retaining portion, a soldering portion extending from a back end of the retaining portion. The soldering portion defines a plurality of soldering legs extending downwards, and the contacting portions of the two power contacts of each power contact pair are arranged alternately in a transverse direction.

Description

Electrical connector

The invention relates to an electrical connector, in particular to an electrical connector capable of effectively improving the heat generation of conductive terminals.

The power terminal of the traditional electrical connector is usually formed from the front end of the metal sheet or divided into a plurality of contact arms. When the electrical connector transmits current, the highest temperature of the power terminal of the electrical connector is the contact point area of the contact arm. The contact method of the contact point is only line contact, which restricts the current channel. In the case of the limited width of the power terminal, the power terminal is likely to generate heat due to the current impedance, which may cause the temperature of the contact point to be too high.

In view of this, it is indeed necessary to further improve the traditional electrical connector to solve the above problems.

An object of the present invention is to provide an electrical connector that can effectively suppress heat generation of conductive terminals.

In order to achieve the above object, the present invention provides an electrical connector, which has:

The insulating body has a mounting portion for mounting on the circuit board, a butting portion extending forward from the mounting portion, and a plurality of terminal slots extending in the front-rear direction; and

The plural power terminal pairs are fixed in the corresponding terminal grooves of the aforementioned insulating body and are divided into at least two rows arranged along the height direction. Each of the aforementioned power terminal pairs in each row includes two power terminals, and each power terminal includes a Corresponding to the holding portion in the terminal groove, a plurality of contact portions extending forward from the front end of the holding portion, and a welding portion extending from the rear end of the holding portion, the welding portion having a plurality of solder legs extending downward;

The contact portions of the two power terminals in each of the aforementioned power terminal pairs are alternately and cyclically arranged in the lateral direction.

As a further improvement of the present invention, the power supply terminal pairs are arranged in pairs in the height direction to form a group, and two power supply terminal pairs in each group of power supply terminal pairs are opposed and spaced apart in the height direction.

As a further improvement of the present invention, the contact portions of the power supply terminal pairs located in the same row are arranged in two rows staggered in the front-rear direction.

As a further improvement of the present invention, the contact area of the contact portion of the aforementioned power terminal pair in the same row is in the same horizontal plane when docked with the docking element.

As a further improvement of the present invention, two adjacent contact portions located in the same row are staggered along the front-rear direction.

As a further improvement of the present invention, wherein the two power terminals in each of the aforementioned power terminal pairs are an outer terminal and an inner terminal, respectively, the holding portions of the two power terminals in each of the aforementioned power terminal pairs are arranged along the height direction, And it is installed and fixed in the same first terminal groove forward from the back side of the aforementioned mounting portion.

As a further improvement of the present invention, the angle between the contact arm of the outer terminal and the horizontal plane is greater than the angle between the contact arm of the inner terminal and the horizontal plane.

As a further improvement of the present invention, in the top-down direction, the length of the holding portions of the four power terminals of each pair of power terminal pairs in the foregoing group along the front-rear direction decreases in sequence.

As a further improvement of the present invention, the top wall of the insulating body is provided with a plurality of first heat dissipation grooves penetrating it in the height direction, and the first heat dissipation groove communicates with the first terminal groove corresponding to the inside thereof.

As a further improvement of the present invention, each of the aforementioned first heat dissipation grooves has a long shape extending in the front-rear direction, and is located above the corresponding aforementioned contact portion to expose the contact portion outward.

Compared with the prior art, the electrical connector of the present invention arranges the contact portions of the two power terminals centered in the power terminals in a row along the height direction to form the same row of contact portions, and the plural contact portions of the two power terminals alternate in the lateral direction The cyclic setting can effectively increase the current channel, improve the heat generation of the power terminal, and improve the transmission reliability of the electrical connector.

Please refer to the first to ninth figures for the first preferred embodiment of the electrical connector of the present invention. The electrical connector 100 includes an insulating body 1 and a plurality of power terminal pairs 2 fixed to the insulating body 1. For ease of explanation, the following will consider the mating end of the electrical connector 100 as the front end, and the other end opposite to the mating end as the rear end, that is, the front-back direction is the electrical connector 100 and the mating element (not shown) The docking direction, in addition, defines one direction perpendicular to the front-rear direction as the lateral direction, and the other direction perpendicular to the front-rear direction as the height direction. In this embodiment, the dimension of the insulating body 1 in the lateral direction is greater than its height The dimensions in the direction and the front-rear direction.

Please refer to the first to fourth figures in conjunction with the eighth to ninth figures. In the present invention, the insulating body 1 has a mounting portion 11, a butting portion 12 extending forward from the mounting portion 11, a plurality of edges The first terminal groove 13 extending in the front-rear direction and the plurality of partitions 14 extending in the front-rear direction are provided with the foregoing partition 14 between every two adjacent first terminal grooves 13. The first terminal groove 13 penetrates the insulating body 1 in the front-rear direction, and the partition 14 extends forward from the mounting portion 11 to the front end surface 121 of the butting portion 12.

The docking portion 12 has a docking space 120 opened forward to receive a docking element, and the first terminal groove 13 communicates with the docking space 120.

In this embodiment, the aforementioned insulating body 1 has upper and lower rows of first terminal slots 13 and a partition wall 15 formed between the upper row of first terminal slots 13 and the lower row of first terminal slots 13. It extends inside the mounting portion 11 in the lateral direction, and separates the first terminal grooves 13 in the upper and lower rows. Further, the partition wall 15 extends forward to the front end surface of the mounting portion 11, and it does not extend forward into the docking portion 12.

The rear side of the mounting portion 11 has a first mounting surface 111, a second mounting surface 112, and a third mounting surface 113 spaced along the front-rear direction, wherein the third mounting surface 113, the second mounting surface 112, and the first mounting surface 111 are sequentially arranged in the front-rear direction.

Referring to the fourth and ninth figures, in this embodiment, the first terminal groove 13 includes a through groove 131 penetrating the mounting portion 11 in the front-rear direction and a plurality of fixing grooves communicating with the through groove 131 132, the fixing grooves 132 are arranged in pairs and symmetrically. In this embodiment, the first terminal groove 13 has two pairs of fixing grooves 132 spaced apart along the height direction, and two fixing grooves 132 in each pair are separated On both sides of the aforementioned through slot 131 in the lateral direction. In the same first terminal groove 13, the extension length of the fixing groove 132 on the upper side in the front-rear direction is greater than the extension length of the fixing groove 132 on the lower side.

As shown in the fifth to ninth figures, the power supply terminal pair 2 is accommodated in the corresponding first terminal slot 13, and each power supply terminal pair 2 includes two power supply terminals 21, each of which is provided with There are a holding portion 201 held in the first terminal groove 13, a plurality of contact portions 202 extending forward from one end of the holding portion 201, and a welding portion 203 extending from the other end of the holding portion 201, each of the aforementioned power terminals The contact portions 202 of the two pieces of power terminals 21 in line 2 are arranged in a row in the height direction, and the plural contact portions 202 of the two pieces of power terminals 21 are alternately and cyclically arranged in the lateral direction.

The power supply terminal pair 2 is divided into two rows arranged oppositely in the height direction, that is, an upper row power supply terminal pair and a lower row power supply terminal pair, and the power supply terminal pair 2 is arranged in a pair along the height direction to form a group, and each group of power supply terminals The two power supply terminal pairs 2 in the pair 2 are opposed and spaced apart along the aforementioned height direction. In the front-rear direction, the welding part 203 of the upper row of power terminal pairs is located on the rear side of the second mounting surface 102, and the welding part of the lower row of power terminal pairs is located between the second mounting surface 102 and the third mounting surface 103.

In this embodiment, each power terminal 21 has three contact portions 202 extending forward from its holding portion 201. The holding portion 201 is a sheet-like structure parallel to the horizontal plane, and the contact portion 202 is curved, and It has a contact area 2020 that protrudes toward the aforementioned partition wall 15.

The contact portions 202 of the aforementioned power terminal pair 2 in the same row are arranged in two rows staggered in the front-rear direction. At the same time, the contact areas 2020 of the contact portions 202 of the aforementioned power terminal pair 2 in the same row are on the same horizontal plane. Further, two adjacent contact portions 202 located in the same row are staggered in the front-rear direction. In this way, when the docking element is inserted, the contact portions 202 arranged in two rows staggered in the front-rear direction can successively contact the docking element respectively, so as to realize multi-level and multi-contact contact, making the contact more sufficient and enhancing the electrical connection The stability and the stability of the current transmission, in addition, make the distribution of the insertion and extraction force between the butt components uniform, reduce the heat generation of the contact surface.

The two power terminals 21 in each of the aforementioned power terminal pairs 2 are respectively an external terminal 211 and an internal terminal 212, wherein compared to the external terminal 211, the holding portion 201 and the contact portion 202 of the internal terminal 212 are closer to the insulating body 1的间壁15。 The partition wall 15. In the front-rear direction, the contact portion 202 of the outer terminal 211 is disposed forward of the contact portion 202 of the inner terminal 212. The contact portion 202 of the outer terminal 211 first contacts the docking element, and the contact portion 202 of the inner terminal 212 contacts the docking element. This reduces the insertion and extraction force, making the insertion and removal feel better, and avoids the elastic contact arm after long insertion and removal Deformation and failure to ensure long-term electrical connection.

The holding portions 201 of the two power terminals 21 in each of the power terminal pairs 2 are spaced apart along the height direction, and are mounted and fixed in the same first terminal slot 13 from the rear side of the mounting portion 11 forward. Each of the two holding portions 201 in the lateral direction is provided with an interference portion 2011 protruding outward, and the interference portion 2011 interferes with the corresponding fixing groove 132 of the first terminal groove 13.

As shown in the seventh figure, in the direction from top to bottom, the length of the holding portion 201 of the four power terminals 21 of each power terminal pair 2 in the foregoing group decreases sequentially along the front and rear directions, that is, in the upper row Of the two power terminals 21 in the power terminal pair 2, the length of the holding portion 201 of the outer terminal 211 in the front-rear direction is greater than the length of the holding portion 201 of the inner terminal 212; the two power terminals 21 in the lower power terminal pair 2 In the middle, the length of the holding portion 201 of the inner terminal 212 in the front-rear direction is greater than the length of the holding portion 201 of the outer terminal 211. In addition, the length of the holding portion 201 of the inner terminal 212 in the upper row of power terminal pairs 2 in the front-rear direction is greater than the length of the holding portion 201 of the inner terminal 212 in the lower row of power terminal pairs 2.

The welding portion 203 includes a plate-shaped portion 2031 bent downward and extending from the rear end of the holding portion 201 and a plurality of solder legs 2032 extending downward from the bottom end of the plate-shaped portion 2031. In this embodiment, the plate-shaped portion 2031 The portion 2031 is disposed parallel to the vertical plane, and the aforementioned solder leg 2032 extends in the vertical direction to be inserted into an external circuit board (not shown).

Each of the aforementioned power terminals 21 has a plurality of elastic contact arms 204 extending forward from the front end of its holding portion 201, the contact portion 202 is located on the front side of the corresponding contact arm 204 to be in contact with the docking element, and the contact arm 204 is forward It passes through the first terminal groove 13 and is accommodated in the docking portion 12.

The angle between the contact arm 204 of the outer terminal 211 and the horizontal plane is greater than the angle between the contact arm 204 of the inner terminal 212 and the horizontal plane. In this embodiment, the inner terminal 212 further has a connecting arm 205 connecting the contact arm 204 and the holding portion 201. The bending extension direction of the connecting arm 205 and the contact arm 204 is opposite to make the angle between the two The opening faces inward (that is, toward the aforementioned partition wall 15).

Specifically, taking the upper power terminal pair 2 as an example, the connecting arm 205 extends forward and downward from the front end of the holding portion 201, and the contact arm 204 extends forward and downward from the front end of the connecting arm 205 , So that the angle opening between the contact arm 204 and the connection arm 205 faces downward. Further, the two holding portions 201 of the upper power terminal pair 2 and the portion (including the plurality of contact arms 204, the connecting arms 205, and the contact portion 202) on the front side of the foregoing holding portion 201 are held by the two lower power terminal pairs 2 The portion 201 and the portion on the front side of the holding portion 201 are provided in mirror symmetry.

Please refer to the first to third figures in conjunction with the ninth figure. In this embodiment, the electrical connector 100 further has a plurality of signal terminals 3 on one side of the power terminal pair 2 in the lateral direction. The insulating body 1 further has a plurality of second terminal grooves 16 on the side of the first terminal groove 13.

Each signal terminal 3 includes a fixing portion 31, a plug portion 32 extending from one end of the fixing portion 31, and a pin 33 extending from the other end of the fixing portion 31. The fixing portion 31 is inserted into and fixed in the second terminal groove 16 from the rear side of the mounting portion 11, and the insertion portion 32 on the front side of the fixing portion 31 protrudes into the docking portion 12 to realize electrical connection with the docking device Sexual connection. In this embodiment, barbs 311 are provided on both sides of the fixing portion 31, and the barbs 311 interfere with the mounting portion 11 to achieve the fixation of the signal terminal 3 in the insulating body 1 to prevent the docking device The signal terminal 3 shakes during docking to improve docking stability.

In the electrical connector 100 of the present invention, the contact portions 202 of the two power terminals aligned in the power terminal are arranged in a row along the height direction to form the same row of contact portions, and the plural contact portions 202 of the two power terminals are alternately and cyclically arranged in the lateral direction. It can effectively increase the current channel, improve the heat generation of the power terminal pair 2, and improve the transmission reliability of the electrical connector 100.

Please refer to the tenth to thirteenth figures for the second preferred embodiment of the electrical connector of the present invention. The electrical connector 100' includes an insulating body 1'and a plurality of power terminals fixed to the insulating body 1' Pair 2', wherein the basic structure and assembly relationship of the insulating body 1'and the power terminal pair 2'are the same as the electrical connector 100 in the first preferred embodiment, which will not be repeated here, and only the differences will be described below Description:

A plurality of first heat dissipation grooves 171' are formed on the top wall 17' of the insulating body 1', the first heat dissipation grooves 171' penetrate the top wall 17' along the height direction, and the first heat dissipation groove corresponds to the first The terminal grooves 13' are in communication. Further, in this embodiment, the top wall 17' defines two rows of the first heat dissipation grooves 171' aligned in the front-rear direction, and each row of the first heat dissipation grooves 171' is arranged side by side in the lateral direction In the direction, the length of the first heat dissipation groove 171' located in the front row in the front-rear direction is greater than the length of the first heat dissipation groove 171' located in the rear row in the front-rear direction.

Each of the power terminal pairs 2'at least on the upper side of the power terminal 21' has at least one second heat dissipation slot 206', the second heat dissipation slot 206' is opened on the corresponding holding portion 201' and extends along the height direction The holding portion 201' is penetrated. In this embodiment, the holding portion 201' of the two power terminals 21' in each upper row of power terminal pairs 2'is provided with the aforementioned second heat dissipation slot 206', and the Of the two power terminals 21', only the power terminal located on the upper side (that is, the inner terminal 212' in the lower row power terminal pair 2') is provided with the aforementioned second heat dissipation groove 206'.

Since the holding portion 201' is fixed in the corresponding first terminal slot 13', the heat generated by the power supply terminal 21' can be passed through the second heat dissipation slot 206', the first terminal slot 13' and the first heat dissipation slot 171' is dissipated to avoid heat accumulation inside the insulating body 1'.

In addition, at least one third heat dissipation slot 207' is formed in the plate-shaped portion 2031' of each power supply terminal 21' in the upper row of power terminal pairs 2', and in the height direction, the third heat dissipation slot on the outer terminal 211' The length of 207' is greater than the length of the third heat sink 207' on the inner terminal 212'. In addition, the projection of the third heat dissipation slot 207' on the two power supply terminals 21' of each of the two power supply terminals 21' in the upper row on the vertical plane at least partially overlaps, and the third heat dissipation slot 207' on the vertical plane Of the first terminal slot 13' of the lower row falls inside the projection of the vertical plane, that is, the third heat dissipation slot 207' is aligned with the first terminal slot 13' of the lower row along the front-rear direction. In this embodiment, the projection of the third heat dissipation groove 207' on the inner terminal 212' on the vertical plane falls inside the projection of the third heat dissipation groove 207' on the outer terminal 211' on the vertical plane. In this way, the heat dissipation channel on the outer side is larger, so as to quickly dissipate the heat on the power terminal.

Please refer to the fourteenth to seventeenth figures, which is the third preferred embodiment of the electrical connector of the present invention. The electrical connector 100'' includes an insulating body 1'' and is fixed to the insulating body 1'' The plural power terminal pairs 2" and the signal terminals 3", wherein the basic structure and the assembly relationship of the insulating body 1" and the power terminal pairs 2" are the same as the electrical connector 100 in the first preferred embodiment. This will not be repeated here, and the following only explains the differences:

The first heat dissipation groove 171'' of the insulating body 1'' is opened at the front of the top wall 17'' and is elongated in the front-rear direction. The first heat dissipation groove 171'' is located at the corresponding contact portion 202 ”Above to expose the contact 202 ″ to the outside. The top wall 17'' is also provided with a plurality of notches 172'' at the rear thereof, the notches 172'' communicates with the corresponding first terminal slots, and the rear of the pair of power terminals protrudes from the corresponding notches Slot 172".

Each of the aforementioned power terminal pairs 2'' middle and outer terminals 211'' has a contact portion 202'' and a base portion 208'' located on the front side of the contact arm 204'', and the aforementioned contact portion 202'' and the base portion 208'' are both from the aforementioned The contact arm 204'' extends forward, and the base portion 208'' is located on one side of the contact portion 202'' in the lateral direction; in this embodiment, the contact portion 202'' of the outer terminal 211'' is The side portion of the aforementioned base portion 208'' is formed by tearing downward and curved inwardly so that its contact area 2020'' and the contact area 2020'' of the corresponding inner terminal 212'' are substantially aligned .

When not docked with the docking element, the contact area 2020'' of the aforementioned outer terminal 211'' is located inside the contact area 2020'' of the corresponding inner terminal 212''; when docked with the docking element, the pair of power terminals in the same row The contact area 2020'' of the 2'' contact portion 202'' is on the same horizontal plane. Furthermore, in this embodiment, in the front-rear direction, the contact area 2020'' of the contact portion 202'' of the outer terminal 211'' is greater than the contact area 2020' of the contact portion 202'' of the inner terminal 212'' 'Set back.

In addition, the inner terminal 212'' and the outer terminal 211'' of the aforementioned power terminal pair 2'' are arranged along the height direction, and have a fixing structure combining each other to stack and fix the two. In this embodiment, the aforementioned The fixing structure is a convex portion 2112" and a positioning groove 2121" that cooperate with each other. Further, the outer terminal 211" has at least one convex portion 2112" formed to protrude toward the inner terminal 212". The inner terminal The 212" has a positioning groove 2121" into which the aforementioned convex portion 2112" is inserted and fixed.

The electrical connector 100'' further includes a positioning seat 4'' that simultaneously fixes the signal terminal 3'' and the power supply terminal pair 2'' in the insulating body 1''. The positioning seat 4'' is elongated and It has a plurality of through holes 41'' for soldering feet 2032'' and pins 33''.

In particular, it should be pointed out that for those of ordinary skill in the art, equivalent changes made to the present invention under the teaching of the present invention should still be included in the scope claimed by the patent application scope of the present invention.

100, 100', 100'': electrical connectors 1, 1', 1'': insulating body 11: Installation Department 111: first mounting surface 112: second mounting surface 113: third mounting surface 12: Docking Department 120: docking space 121: front face 13, 13': the first terminal slot 131: through slot 132: fixed groove 14: Partition 15: partition 16: Second terminal slot 17', 17'': top wall 171', 171'': the first heat sink 172'': Notch 2, 2', 2'': power terminal pair 201, 201': holding part 2011: Interference Department 202, 202'': contact 2020, 2020'': contact area 203: Welding Department 2031, 2031': plate-shaped part 2032, 2032'': Welding feet 204: contact arm 205: connecting arm 206': second heat sink 207': third heat sink 208'': base 21, 21': power terminal 211, 211', 211'': external terminals 2112'': convex 212, 212', 212'': inner terminal 2121'': positioning groove 3.3'': signal terminal 31: fixed part 311: Barbed 32: Dock 33, 33'': Pin 4'': positioning seat 41'': through hole

The first figure is a perspective assembly view of the first preferred embodiment of the electrical connector of the present invention. The second figure is an exploded perspective view of the electrical connector shown in the first figure. The third diagram is another view of the electrical connector shown in the first diagram. The fourth figure is a perspective schematic view of the insulating body of the electrical connector shown in the second figure. The fifth figure is a perspective view of a set of power terminal pairs of the electrical connector shown in the second figure. The sixth figure is an exploded perspective view of a pair of power terminal pairs of the electrical connector shown in the fifth figure. The seventh figure is a side view of a pair of power terminal pairs of the electrical connector shown in the fifth figure. The eighth figure is a schematic cross-sectional view of the electrical connector shown in the first figure. The ninth figure is a schematic cross-sectional view of the electrical connector shown in the first figure after one of the power terminal pairs is removed. Figure 10 is a perspective assembly view of the second preferred embodiment of the electrical connector of the present invention. Figure 11 is an exploded perspective view of the electrical connector shown in Figure 10. Figure 12 is an exploded view of a set of power terminal pairs of the electrical connector shown in Figure 11. Figure 13 is a schematic cross-sectional view of the electrical connector shown in Figure 10. Figure 14 is a perspective assembly view of a third preferred embodiment of the electrical connector of the present invention. Figure 15 is an exploded perspective view of the electrical connector shown in Figure 14. Figure 16 is a partial exploded view of a pair of power terminal pairs of the electrical connector shown in Figure 15. Figure 17 is a side view of a pair of power terminal pairs of the electrical connector shown in Figure 15.

201: Holding Department

2011: Interference Department

202: contact

203: Welding Department

204: contact arm

Claims (10)

An electrical connector, including: The insulating body has a mounting portion for mounting on the circuit board, a butting portion extending forward from the mounting portion, and a plurality of terminal slots extending in the front-rear direction; and The plural power terminal pairs are fixed in the corresponding terminal grooves of the aforementioned insulating body and are divided into at least two rows arranged along the height direction. Each of the aforementioned power terminal pairs in each row includes two power terminals, and each power terminal includes a Corresponding to the holding portion in the terminal groove, a plurality of contact portions extending forward from the front end of the holding portion, and a welding portion extending from the rear end of the holding portion, the welding portion having a plurality of solder legs extending downward; The contact portions of the two power terminals in each of the aforementioned power terminal pairs are alternately and cyclically arranged in the lateral direction. The electrical connector as described in item 1 of the patent application range, wherein the power supply terminal pairs are arranged in pairs in the height direction to form a group, and two power supply terminal pairs in each group of power terminal pairs are opposed and spaced apart in the height direction . The electrical connector as described in item 2 of the patent application scope, wherein the contact portions of the power supply terminal pairs located in the same row are arranged in two rows staggered in the front-rear direction. The electrical connector as described in item 3 of the patent application scope, wherein the contact area of the contact portion of the aforementioned power terminal pair in the same row is on the same horizontal plane when docked with the docking element. The electrical connector as described in item 3 or 4 of the patent application scope, wherein two adjacent contact portions in the same row are staggered along the front-rear direction. The electrical connector as described in item 2 of the patent application scope, wherein the two power terminals of each of the aforementioned power terminal pairs are an outer terminal and an inner terminal, respectively, and the holding portions of the two power terminals of each of the aforementioned power terminal pairs They are arranged along the aforementioned height direction, and are installed and fixed in the same first terminal groove from the back side of the aforementioned mounting portion. The electrical connector as described in item 6 of the patent application range, wherein the angle between the contact arm of the outer terminal and the horizontal plane is greater than the angle between the contact arm of the inner terminal and the horizontal plane. The electrical connector as described in item 6 of the patent application scope, wherein in the top-down direction, the lengths of the holding portions of the four power terminals of each pair of power terminals in the foregoing group of power terminals are sequentially reduced along the front and rear directions. The electrical connector as described in item 6 of the patent application range, wherein the top wall of the insulating body is provided with a plurality of first heat dissipation grooves penetrating it in the height direction, and the first heat dissipation groove and the first terminal groove corresponding to the inside thereof Connected. The electrical connector as described in item 9 of the patent application range, wherein each of the aforementioned first heat dissipation grooves is a long strip extending in the front-rear direction, and is located above the corresponding aforementioned contact portion to expose the contact portion outward.

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