Tin climbing prevention structure for welding of flat connector

Abstract

The invention discloses a flat connector welding tin climbing prevention structure, a plurality of terminals of a flat connector can be accommodated in terminal accommodating grooves in a plastic shell, each terminal comprises a holding part, a welding part and an elastic supporting arm, the holding parts can be fixedly connected with the terminal accommodating grooves, and the welding parts are fixedly connected with the elastic supporting arms. A welding surface located on the outer side of the lower end of the plastic shell is formed on a welding part arranged at the lower end of the holding part, the welding surface can be flatly attached to and welded to the PAD surface on the circuit board, the lower end of the elastic supporting arm is fixedly connected with the welding part, and a conduction contact part used for elastic contact conduction is formed at the upper end of the elastic supporting arm. A scaling powder containing groove of a concave structure is formed in the inner side wall of the lower end of each terminal containing groove of the plastic shell, redundant soldering tin and scaling powder generated when the welding parts of the terminals are welded to the circuit board can be contained in the scaling powder containing grooves, the stability of signal transmission is guaranteed, the high-frequency transmission performance of the connector is guaranteed, and the service life of the connector is prolonged. And the welding strength of the terminal and the circuit board is also improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of terminals for connector, in particular to a kind of flat connector soldering anti-tin climbing structure. BACKGROUND

[0002] Chip module 10 and circuit board 20 are generally connected by flat connector 30 to achieve functional expansion, and the conductive terminal of the flat connector is a crimping structure, which includes a holding portion, a soldering portion, an elastic support arm and an elastic contact arm 14. The soldering portion of the terminal is located outside the lower end of the plastic shell, and the lower side of the soldering portion forms a horizontal soldering surface. The soldering surface of the soldering portion is soldered to the circuit board to achieve electrical connection between the terminal and the circuit board. The holding portion of the terminal is used for fixing and positioning the terminal in the plastic shell. The elastic contact arm is located at the upper end of the holding portion, and a protruding upper contact point 141 is formed on the elastic contact arm outside the upper end of the plastic shell. The lower contact point 142 of the elastic contact arm is also provided inside the plastic shell. When the upper contact point on the elastic contact arm is pressed down by the chip module, the lower contact point on the elastic contact arm is in close contact with the conductive contact portion at the upper end of the elastic support arm. At this time, the terminal forms a closed loop, and a double-channel signal transmission structure is formed between the chip module and the circuit board to improve the high-frequency performance of the flat connector.

[0003] During the SMT soldering process of the soldering portion of the terminal with the circuit board, the metal tin in the solder paste is melted by heating in the reflow soldering furnace. After the reflow soldering furnace cools down, the metal tin solidifies, so that the terminal is soldered to the surface of the PAD of the circuit board. During the dissolution of the solder paste, the main components of the solder paste are metal tin beads, flux (rosin), activator, etc. The active substances in the solder paste have good flowability, which can carry the dissolved flux to the conductive contact portion at the upper end of the elastic support arm of the terminal. After the flux solidifies, it adheres to the surface of the conductive contact portion, causing poor contact between the conductive contact portion at the upper end of the elastic support arm of the terminal and the lower contact point of the elastic contact arm, which seriously affects the high-frequency performance of the connector during signal transmission. SUMMARY

[0004] To make up for the above shortcomings, the present application provides a flat connector soldering anti-tin climbing structure, which can prevent the flux from flowing to the surface of the conductive contact portion at the upper end of the elastic support arm of the terminal during soldering of the terminal with the circuit board, thereby fully ensuring the signal transmission stability and high-frequency transmission performance of the flat connector.

[0005] The technical scheme adopted by the present application to solve its technical problems is: a flat connector soldering anti-tin climbing structure, the flat connector comprises a plastic shell and a terminal, a plurality of terminal accommodating grooves are arranged in the plastic shell, a plurality of terminals can be accommodated in each terminal accommodating groove, the terminal comprises a holding part, a soldering part and an elastic support arm, the holding part can be fixedly connected with the terminal accommodating groove, the soldering part is arranged at the lower end of the holding part, a soldering surface is formed on the soldering part and located outside the lower end of the plastic shell, the soldering surface can be flatly and soldered on the PAD surface of the circuit board, the lower end of the elastic support arm is fixedly connected with the soldering part, a conductive contact part for elastic contact and conduction is formed on the upper end of the elastic support arm, a recessed structure of a flux containing groove is formed on the inner side wall of the lower end of each terminal accommodating groove of the plastic shell, and the excess solder and flux generated when the soldering part of the terminal is soldered with the PAD surface of the circuit board can be contained in the flux containing groove.

[0006] As a further improvement of the present application, the flux containing groove is arranged on the side wall of the terminal accommodating groove close to the holding part of the terminal.

[0007] As a further improvement of the present application, the lower end of the terminal accommodating groove forms a stepped structure with an outwardly expanded size, at least one protrusion is arranged on the stepped surface of the stepped structure, and the lower end surface of the protrusion is higher than the lower end surface of the plastic shell, the flux containing groove is a gap between the protrusion and the inner side wall of the lower end of the terminal accommodating groove and the adjacent protrusion or a groove structure on the side wall of the protrusion.

[0008] As a further improvement of the present application, a sink structure is formed at the lower end of the plastic shell, and each terminal accommodating groove is arranged on the bottom surface of the sink structure.

[0009] As a further improvement of the present application, the flux containing groove is a through hole groove penetrating through the side wall of the plastic shell.

[0010] As a further improvement of the present application, one side of the terminal accommodating groove forms a terminal holding groove with a width greater at the upper end than at the lower end, the holding part of the terminal is a T-shaped structure with a width greater at the upper end than at the lower end, an outward protruding holding clamping point is formed on the side edge of the upper end of the terminal holding part along the width direction, the holding part of the terminal can be closely inserted into the terminal holding groove, the holding clamping point on the side edge of the holding part of the terminal can interfere with the side wall of the terminal holding groove, the stepped surface between the upper and lower ends of the holding part of the terminal is stopped on the stepped surfaces of the upper and lower ends of the terminal holding groove, and the flux containing groove is located on the side wall of the terminal holding groove along the thickness direction of the terminal holding part.

[0011] As a further improvement of the present application, a communicating siphon groove is formed on the holding part and the soldering part of the terminal, and the siphon groove on the terminal is in communication with the flux containing groove on the plastic shell.

[0012] As a further improvement of the present application, the siphon groove on the terminal is located at one end of the terminal holding portion, which is lower in height than the height of the conducting contact portion at the upper end of the elastic support arm.

[0013] As a further improvement of the present application, the siphon groove on the terminal is located at one end of the terminal holding portion, which is lower in height than the height of the conducting contact portion at the upper end of the elastic support arm.

[0014] As a further improvement of the present application, the siphon groove on the terminal is located at one end of the terminal holding portion, which is lower in height than the height of the conducting contact portion at the upper end of the elastic support arm.

[0015] The present application has the beneficial technical effects that: the solder flux containing groove is formed on the side wall of the lower end of the terminal containing groove of the plastic shell, when the terminal welding portion of the flat connector is welded with the circuit board, the excess solder paste and solder flux enter the solder flux containing groove, thereby reducing the flow of the solder flux to the conducting contact portion at the upper end of the elastic support arm, and further preventing the molten solder paste from climbing along the elastic support arm to the surface of the conducting contact portion, thereby ensuring that when the upper contact point of the elastic contact arm of the terminal of the chip module is pressed, the lower contact point of the elastic contact arm stably contacts and conducts with the surface of the conducting contact portion at the upper end of the elastic support arm, thereby ensuring the stability of the signal transmission and the high frequency transmission performance of the connector. The siphon groove is further provided on the terminal to contain the solder flux and the excess solder, and further increase the welding area of the terminal with the circuit board, improve the welding strength of the terminal with the circuit board, and effectively prevent the welding from being opened under the action of the pulling force. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 isometric view of the chip module and the circuit board electrically connected through the flat connector of the present application;

[0017] Figure 2 isometric view of the chip module and the circuit board electrically connected through the flat connector of the present application;

[0018] Figure 3 isometric view of the chip module and the circuit board electrically connected through the flat connector of the present application;

[0019] Figure 4 isometric view of the chip module and the circuit board electrically connected through the flat connector of the present application;

[0020] Figure 5 isometric view of the chip module and the circuit board electrically connected through the flat connector of the present application;

[0021] Figure 6 isometric view of the chip module and the circuit board electrically connected through the flat connector of the present application;

[0022] Figure 7 This is an exploded perspective view of the present invention;

[0023] Figure 8 This is a first perspective view of the first structure of the present invention;

[0024] Figure 9 This is a second perspective view of the first type of terminal of the present invention;

[0025] Figure 10 for Figure 9 Enlarged view of section A in the middle;

[0026] Figure 11 for Figure 9 Sectional view along the BB direction;

[0027] Figure 12 for Figure 11 Central C-section defense map;

[0028] Figure 13 This is a front view of the first structure of the present invention in the state of being soldered to the circuit board;

[0029] Figure 14 for Figure 13 Enlarged view of section D in the middle;

[0030] Figure 15 This is a perspective view of the plastic shell of the first structure of the present invention;

[0031] Figure 16 for Figure 15 Enlarged view of section E in the middle;

[0032] Figure 17 This is a perspective view of the second type of terminal of the present invention;

[0033] Figure 18 for Figure 17 Enlarged view of section F in the middle;

[0034] Figure 19 for Figure 17 Central GG-direction sectional view;

[0035] Figure 20 for Figure 19 Central H-section defense map;

[0036] Figure 21 This is a front view of the second structure of the present invention in its soldered state with the circuit board;

[0037] Figure 22 for Figure 21 Enlarged view of the middle section (I);

[0038] Figure 23 This is a perspective view of the plastic shell of the second structure of the present invention;

[0039] Figure 24 For Figure 23 Enlarged view of middle J section. DETAILED DESCRIPTION

[0040] Embodiment: A flat connector soldering anti-tin climbing structure, the flat connector comprises a plastic shell 2 and a terminal 1, a plurality of terminal accommodating grooves 21 are arranged in the plastic shell 2, a plurality of terminals 1 can be accommodated in each terminal accommodating groove 21, the terminal 1 comprises a holding part 11, a soldering part 12 and an elastic support arm 13, the holding part 11 can be fixedly connected with the terminal accommodating groove 21, the soldering part 12 is arranged at the lower end of the holding part 11, a soldering surface is formed on the soldering part 12, which is located outside the lower end of the plastic shell 2, the soldering surface can be flatly and soldered on the PAD surface on the circuit board, the lower end of the elastic support arm 13 is fixedly connected with the soldering part 12, a conduction contact part 131 for elastic contact conduction is formed at the upper end of the elastic support arm 13, a recessed structure of flux 4 containing groove 22 is formed on the inner side wall of the lower end of each terminal accommodating groove 21 of the plastic shell 2, the excess solder tin 3 and the flux 4 generated when the soldering part 12 of the terminal 1 is soldered with the PAD surface on the circuit board can be contained in the flux 4 containing groove 22.

[0041] The flux 4 containing groove 22 is arranged on the side wall of the lower end of the terminal accommodating groove 21 of the plastic shell 2 of the flat connector, when soldering, the flux 4 in the molten state flows into the flux 4 containing groove 22, and after solidification, the flux 4 is solidified inside the flux 4 containing groove 22, so that the amount of flux 4 flowing onto the surface of the elastic support arm 13 during soldering is greatly reduced, thereby ensuring that the terminal 1 forms a stable closed loop conduction structure when the chip module is pressed downward, ensuring stable transmission of signals by the terminal 1 in the connector, and ensuring double-channel high-frequency transmission.

[0042] The flux 4 containing groove 22 is arranged on the side wall of the lower end of the terminal accommodating groove 21 of the plastic shell 2 of the flat connector, when soldering, the flux 4 in the molten state flows into the flux 4 containing groove 22, and after solidification, the flux 4 is solidified inside the flux 4 containing groove 22, so that the amount of flux 4 flowing onto the surface of the elastic support arm 13 during soldering is greatly reduced, thereby ensuring that the terminal 1 forms a stable closed loop conduction structure when the chip module is pressed downward, ensuring stable transmission of signals by the terminal 1 in the connector, and ensuring double-channel high-frequency transmission.

[0043] The lower end of the terminal accommodating groove 21 forms a stepped structure with an outwardly expanded size, at least one protrusion 23 is arranged on the stepped surface of the stepped structure, and the lower end surface of the protrusion 23 is higher than the lower end surface of the plastic shell 2, the flux 4 containing groove 22 is a gap between the protrusion 23 and the inner side wall of the lower end of the terminal accommodating groove 21 and the adjacent protrusion 23 or a groove structure on the side wall of the protrusion 23. By arranging the protrusion 23, the height of the lower end of the flux 4 containing groove 22 can be reduced, so that it is closer to the soldering surface, thereby fully absorbing the excess solder tin 3 and the flux 4.

[0044] The lower end of the plastic shell 2 is formed with a sink structure, and each terminal receiving groove 21 is arranged on the bottom surface of the sink structure. The sink structure can realize the entry of the PAD on the circuit board, reduce the overall height after the connector is connected with the circuit board, and make the lower end surface of the flat plate connector flatly contact the surface of the circuit board to form stable support.

[0045] The flux 4 receiving groove 22 is a through hole groove 25 penetrating the side wall of the plastic shell 2 upward and downward. The through hole groove 25 forms an upward and downward through structure, which can play a siphon role on the flux 4. When the solder paste is melted, the flux 4 can be sequentially absorbed into the through hole groove 25. The upward climbing of the flux 4 along the elastic support arm 13 is avoided.

[0046] One side of the terminal receiving groove 21 is formed with a terminal holding groove 24 with a width greater at the upper end than at the lower end. The holding part 11 of the terminal 1 is in a T-shaped structure with a width greater at the upper end than at the lower end. The holding part 11 of the terminal 1 is tightly inserted into the terminal holding groove 24, and the holding clamping point 111 on the side of the holding part 11 of the terminal 1 is in interference with the side wall of the terminal holding groove 24. The step surface between the upper and lower ends of the holding part 11 of the terminal 1 is stopped on the step surface between the upper and lower ends of the terminal holding groove 24. The flux 4 receiving groove 22 is located on the side wall of the terminal holding groove 24 in the thickness direction of the holding part 11 of the terminal 1. When the terminal 1 is inserted into the terminal receiving groove 21, the holding part 11 of the terminal 1 is inserted into the terminal holding groove 24. When the terminal 1 is inserted to a certain depth, the lower end step surface of the holding part 11 of the terminal 1 is blocked by the step surface of the terminal holding groove 24 and cannot continue to be inserted downward, thereby limiting the insertion depth of the terminal 1. Meanwhile, the holding clamping point 111 on the holding part 11 of the terminal 1 is fixedly connected with the side wall of the terminal holding groove 24 in an embedded manner to form fixed positioning. Since the soldering part 12 of the terminal 1 is soldered on the circuit board, the terminal 1 cannot be pulled upward, thereby realizing the fixed positioning of the terminal 1 and the plastic shell 2. The flux 4 receiving groove 22 arranged on the side wall of the terminal holding groove 24 can guide the flow of the solder 3 and the flux 4 together with the holding part 11 of the terminal 1.

[0047] The holding part 11 and the soldering part 12 of the terminal 1 are formed with a continuous siphon groove 112. The siphon groove 112 on the terminal 1 is in communication with the flux 4 receiving groove 22 on the plastic shell 2. Meanwhile, when the metal tin solidifies, the solder 3 and the flux 4 flow upward along the siphon groove 112 on the holding part 11 of the terminal 1, avoiding the upward flow along the elastic support arm 13. Meanwhile, the siphon groove 112 contains the metal tin, which can increase the soldering area and the soldering force.

[0048] The siphon groove 112 on the terminal 1 is located at one end of the holding part 11 of the terminal 1, and the height of the siphon groove 112 is lower than the height of the conductive contact part 131 at the upper end of the elastic support arm 13. Since the height of the siphon groove 112 is lower than the height of the conductive contact part 131 at the upper end of the elastic support arm 13, the flux 4 cannot reach the surface of the conductive contact part 131 at the upper end of the elastic support arm 13.

[0049] The siphon groove 112 on the terminal 1 is located at one end of the holding part 11 of the terminal 1, and the height of the siphon groove 112 is lower than the height of the conductive contact part 131 at the upper end of the elastic support arm 13. Since the height of the siphon groove 112 is lower than the height of the conductive contact part 131 at the upper end of the elastic support arm 13, the flux 4 cannot reach the surface of the conductive contact part 131 at the upper end of the elastic support arm 13.

[0050] The holding part 11, the welding part 12 and the elastic support part of the terminal 1 are formed as an integrated structure by bending, and the holding part 11 and the welding part 12 are connected by an outer circular arc bent edge, and the elastic support part and the welding part 12 are also connected by an outer circular arc bent edge. In this way, a gap for accommodating the solder 3 can be formed between the welding part 12 of the terminal 1 and the surface of the PAD of the circuit board, and the welding firmness is ensured.

Claims

1. A solder-resistant anti-climbing structure for a flat panel connector, the flat panel connector comprising a plastic shell (2) and terminals (1), wherein a plurality of terminal receiving slots (21) are spaced apart inside the plastic shell, and a plurality of terminals can be accommodated in each terminal receiving slot, the terminals comprising a retaining part (11), a soldering part (12) and an elastic support arm (13), the retaining part being fixedly connected to the terminal receiving slot, the soldering part being disposed at the lower end of the retaining part, and a soldering surface being formed on the soldering part located on the outer side of the lower end of the plastic shell, the soldering surface being able to be flatly attached to and soldered to the PAD surface on the circuit board, the lower end of the elastic support arm being fixedly connected to the soldering part, and a conductive contact part (131) for elastic contact conduction being formed at the upper end of the elastic support arm, characterized in that: The lower inner wall of each terminal receiving groove of the plastic shell has a recessed flux receiving groove (22), and the excess solder (3) and flux (4) generated when the welding part of the terminal is welded to the PAD surface on the circuit board can be contained in the flux receiving groove.

2. The anti-tin creep structure for flat panel connectors according to claim 1, characterized in that: The flux receiving groove is located on the side wall of the terminal receiving groove, which is close to the holding part of the terminal.

3. The anti-tin creep structure for flat panel connectors according to claim 1 or 2, characterized in that: The lower end of the terminal receiving groove forms a stepped structure with an outward expansion. At least one protrusion (23) is provided on the stepped surface of the stepped structure, and the lower end face of the protrusion is higher than the lower end face of the plastic shell. The flux receiving groove is the gap between the protrusion and the inner side wall of the lower end of the terminal receiving groove and the adjacent protrusion or the groove structure on the side wall of the protrusion.

4. The anti-tin creep structure for flat panel connectors according to claim 3, characterized in that: The lower end of the plastic shell has a recessed groove structure, and the terminal receiving slots are arranged at intervals on the bottom surface of the recessed groove structure.

5. The anti-tin creep structure for flat panel connectors according to claim 1 or 2, characterized in that: The flux receiving tank is a through-hole groove (25) that runs vertically along the side wall of the plastic shell.

6. The anti-tin creep structure for flat panel connectors according to claim 1, characterized in that: A terminal holding groove (24) with an upper width greater than a lower width is formed on one side of the terminal receiving groove. The terminal holding part is a T-shaped structure with an upper width greater than a lower width. A protruding holding point (111) is formed on the side of the upper end of the terminal holding part along its width direction. The terminal holding part can be tightly inserted into the terminal holding groove, and the holding point on the side of the terminal holding part can interfere with the side wall of the terminal holding groove. The step surface between the upper and lower ends of the terminal holding part stops on the step surface at the upper and lower ends of the terminal holding groove. The flux receiving groove is located on the side wall of the terminal holding groove along the thickness direction of the terminal holding part.

7. The anti-tin creep structure for flat panel connectors according to claim 1, characterized in that: A siphon groove (112) is formed on the holding part and the welding part of the terminal, and the siphon groove on the terminal is directly connected to the flux receiving groove on the plastic shell.

8. The anti-tin creep structure for flat panel connectors according to claim 7, characterized in that: The siphon groove on the terminal is located at one end of the terminal holding part at a height lower than the height of the conductive contact part at the upper end of the elastic support arm.

9. The anti-tin creep structure for flat panel connectors according to claim 7, characterized in that: The siphon groove on the terminal forms an enlarged receiving cavity at one end of the terminal holding part.

10. The anti-tin creep structure for flat panel connectors according to claim 1, characterized in that: The terminal's retaining part, welding part, and elastic support part are an integral structure formed by bending, and the retaining part and welding part are connected by an outer arc bending edge, and the elastic support part and welding part are also connected by an outer arc bending edge.

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