CN215527721U

CN215527721U - High-strength small-spacing LED welding structure

Info

Publication number: CN215527721U
Application number: CN202121787242.1U
Authority: CN
Inventors: 常飞; 王化锋; 杨凤琴; 朱鹏
Original assignee: Jiashan Sansi Photoelectric Technology Co Ltd
Current assignee: Jiashan Sansi Photoelectric Technology Co Ltd
Priority date: 2021-08-02
Filing date: 2021-08-02
Publication date: 2022-01-14
Anticipated expiration: 2031-08-02

Abstract

A high-strength small-spacing LED welding structure comprises a circuit board, a bonding pad, an LED and solder paste. The LED comprises a body and pins. The pin includes a connection section, and a soldering section. The welding section comprises a welding surface and a binding surface. The distance between the edge of the bonding pad and the welding surface is equal to the height of the welding section, the included angle between the inclined plane of the solder paste and the plane of the welding surface is 45 degrees, the included angle can adapt to the natural optimal tin climbing angle formed by the surface tension when the solder paste is melted, and the stability is realized. The welding section is welded with the welding plate by the three welding surfaces, so that the welding area is increased, and the wetting force generated when the solder paste wets the welding surface of the element only acts on the welding surface. The outer side wall of the pin is not affected by wetting force, so that the LED is prevented from being inclined during welding, the welding strength is guaranteed, and the stability during welding is guaranteed.

Description

High-strength small-spacing LED welding structure

Technical Field

The utility model relates to the technical field of LEDs, in particular to a high-strength small-spacing LED welding structure.

Background

The LED display screen is composed of a plurality of LED modules, and the LED modules are formed by orderly arranging and welding a plurality of LEDs according to a uniform interval. Due to the high cost of early LEDs, the spacing between multiple LEDs on indoor and outdoor displays is generally large. Because the visible distance is enough outdoors, even if the distance between the LEDs is larger, the actual effect is not influenced, but the LEDs are watched at a close distance indoors, and products with large distance cannot meet the requirements. With the development of technology, the price of the LED chip is greatly reduced in recent years, so that the popularization of the indoor display screen with small space becomes possible, and the LED display screen is applied to various indoor industries at present. The distance between the LEDs is smaller and smaller, so that the packaging size of the LEDs is smaller, the welding strength is in direct proportion to the welding area, the welding strength is smaller and smaller, the LEDs are easy to fall off in the production and installation processes, and the contradiction exists between the welding strength and the welding area.

As shown in fig. 6, the lead 100 and the pad 200 of the LED soldering structure in the prior art are connected by solder paste 300, and the lead 100 and the pad 200 are not in contact with each other during soldering. The amount of the solder paste is increased in order to improve the soldering strength, but an unreasonable increase may cause the LED400 to be warped in soldering, and a tombstoning phenomenon occurs. In the reflow stage, the solder paste 300 begins to melt, the adhesion of the solder paste 100 begins to disappear, the liquid solder paste has an upward buoyancy due to the action of the surface tension of the liquid before the liquid solder paste wets the leads 100, and the LED400 actually floats on the surface of the liquid solder paste. However, when the solder paste 300 begins to wet the bonding surface of the lead 100, a downward-inclined wetting force is generated, and the smaller the surface tension of the bonding surface of the lead 100, the faster the wetting speed and the stronger the wetting force. When the moment generated by the wetting force and the buoyancy is larger than the weight of the LED400, the pin 100 tilts the LED400 with the bending point thereof as a fulcrum, thereby tilting the LED 400. When the soldering paste is too thick, the probability that the soldering paste on a plurality of pads is not melted simultaneously is greatly increased, so that the tension of a plurality of welding surfaces of the pins is more easily unbalanced, and different skews of a plurality of LEDs are caused. The phenomenon of opposite brightness appears when the LED display screen is seen from left to right, and the phenomenon of yin and yang faces is commonly referred to in the industry.

SUMMERY OF THE UTILITY MODEL

In view of the above, the present invention provides a high-strength small-pitch LED bonding structure to solve the above technical problems.

A high-strength small-spacing LED welding structure comprises a circuit board, at least four welding pads arranged on the circuit board, an LED arranged on the welding pads, and at least four solder pastes connected with the LED and the welding pads. The LED comprises a body and at least four pins arranged on the body. The pin comprises a connecting section connected with the body and a welding section connected with the welding disc. One end of the connecting section is connected with the body, and the other end of the connecting section is connected with the welding section. The welding section comprises three adjacent welding surfaces connected with the solder paste and a binding surface attached to the bonding pad. The welding surface and the edge of the welding pad are arranged at intervals, and the distance between the edge of the welding pad and the welding surface is equal to the height of the welding section. The plane of the attaching surface is perpendicular to the plane of the welding surface and attached to the pad. The solder paste is connected the welding face with the pad is being followed on the cross-section of welding section's center pin the solder paste is right triangle and two right-angle sides's length equals, the inclined plane of solder paste with the contained angle between the place plane of welding face is 45 degrees.

Further, each side of the body is provided with at least two pins.

Further, the plane of the welding section is parallel to the plane of the welding pad.

Further, the lengths of the two right-angle sides of the solder paste are equal on the section along the central axis of the welding section.

Further, the pins are integrally formed, the pins are L-shaped, and the opening direction of the pins faces the body.

Compared with the prior art, the welding section of the high-strength small-spacing LED welding structure comprises three adjacent welding surfaces connected with the solder paste and a joint surface jointed with the bonding pad. The welding surface and the edge of the welding pad are arranged at intervals, and the distance between the edge of the welding pad and the welding surface is equal to the height of the welding section. The messenger is in along on the cross-section of welding section's the center pin, the solder paste is right triangle and two length on right angle limit equal to make the inclined plane of solder paste with the contained angle between the place plane of face of weld is 45 degrees, and the natural best that surface tension formed when this angle can adapt to the solder paste and melts climbs tin angle to have stability. The welding section depends on three welding surfaces and the welding pads for welding, so that the welding area is increased, the welding strength is improved, and the stress is more uniform by means of welding of a plurality of surfaces. When reflow soldering is carried out, the wetting force generated when the solder paste wets the element welding surface can only act on the welding surface, so that the outer side wall of the welding section is not subjected to the wetting force, the pin is prevented from taking the bending point of the pin as a fulcrum, the LED tilts, and the LED is prevented from being tilted during welding. The binding face with the pad laminating has further improved stability, has guaranteed welding strength promptly like this, has guaranteed the steady when welding again.

Drawings

Fig. 1 is a schematic structural diagram of a high-strength small-pitch LED bonding structure according to the present invention.

Fig. 2 is a schematic structural view of an LED and solder paste included in the high-strength small-pitch LED bonding structure of fig. 1.

Fig. 3 is a schematic structural diagram of a lead of the high-strength small-pitch LED bonding structure of fig. 1.

Fig. 4 is a cross-sectional view of a pin, solder paste and pad with the high-strength, small-pitch LED bonding structure of fig. 1.

Fig. 5 is a top view of a bond pad and a bond segment with the high strength, small pitch LED bond structure of fig. 1.

Fig. 6 is a schematic structural diagram of a prior art LED bonding structure.

Detailed Description

Specific examples of the present invention will be described in further detail below. It should be understood that the description herein of embodiments of the utility model is not intended to limit the scope of the utility model.

As shown in fig. 1 to 5, which are schematic structural diagrams of the high-strength small-pitch LED bonding structure provided by the present invention. The high-strength small-pitch LED soldering structure comprises a circuit board 10, at least four pads 20 arranged on the circuit board 10, an LED30 arranged on the pads 20, and at least four solder pastes 40 connecting the LED30 and the pads 20. It is contemplated that the high-strength small-pitch LED soldering structure further includes other functional modules, such as flux, etc., which are well known to those skilled in the art and will not be described herein.

The circuit board 10 is used for disposing the pad 20 and the LED30 and providing a stable output voltage for the LED 30. Which is per se prior art and will not be described in further detail herein.

The solder pads 20 are rectangular in configuration and are used to solder the LEDs 30.

The LED30 includes a body 31 and at least four pins 32 disposed on the body 31. The four pins 32 are respectively located on two sides of the body 31, and at least two pins 32 are arranged on each side of the body 31. The pin 32 is L-shaped and opens toward the body 31. The pins 32 may be integrally formed. The lead 32 includes a connecting section 321 connected to the body 31, and a soldering section 322 connected to the pad 20.

The connecting section 321 is connected to the body 31 at one end and connected to the welding section 322 at the other end, thereby connecting the welding section 322 and the body 31.

The plane of the soldering section 322 is parallel to the plane of the soldering land 20. The soldering segment 322 has a rectangular parallelepiped structure and includes three adjacent soldering surfaces 3221 connected to the solder paste 40 and an engaging surface 3222 engaging with the soldering land 20.

The bonding surface 3221 is spaced apart from the edge of the bonding pad 20, and the distance from the edge of the bonding pad 20 to the bonding surface 3221 is equal to the height of the bonding segment 322, so that the solder paste 40 can be stably bonded. The plane of the attaching surface 3222 is perpendicular to the plane of the welding surface 3221 and is attached to the pad 20, so that the welding section 322 directly contacts with the pad 20, so as to support the body 31 and is not easy to tilt.

The solder paste 40 connects the bonding surface 3221 and the bonding pad 20. In a cross section along the central axis of the soldering segment 322, the solder paste 40 is in a right triangle shape, and since the distance from the edge of the pad 20 to the soldering surface 3221 is equal to the height of the soldering segment 322, the lengths of the two right-angled edges of the solder paste 40 in the cross section along the central axis of the soldering segment 322 are equal, so that the included angle between the inclined surface of the solder paste 40 and the plane where the soldering surface 3221 is located is 45 degrees, the solder paste 40 can be stably soldered to the soldering surface 3221 and the pad 20, the soldering strength is improved, and the angle is adapted to the natural optimal tin climbing angle formed by the surface tension when the solder paste is melted. The welding section 322 is welded with the bonding pad 20 by means of the three welding surfaces 3221, so that the welding area is increased, and the welding strength is improved. In addition, during reflow soldering, the wetting force generated when solder paste wets the soldering surface of the component only acts on the soldering surface 3221, so that the outer side wall of the soldering section 322 is not subjected to the wetting force, and the LED31 is prevented from being tilted by the pin 32 with the bending point thereof as a fulcrum, so that the LED31 is prevented from being inclined during soldering. And the bonding surface 3222 is bonded to the pad 20, so that the leads 32 are more stable, and the stability is further improved.

Compared with the prior art, the soldering segment 322 of the high-strength small-pitch LED soldering structure provided by the utility model comprises three adjacent soldering surfaces 3221 connected with the solder paste 40 and an attaching surface 3222 attached to the soldering land 20. The bonding surface 3221 is spaced apart from the edge of the bonding pad 20, and a distance between the edge of the bonding pad 20 and the bonding surface 3221 is equal to the height of the bonding segment 322. The solder paste 40 is in a right triangle shape on the cross section along the central axis of the soldering section 322, and the lengths of the two right-angle sides are equal, so that the included angle between the inclined plane of the solder paste 40 and the plane of the soldering surface 3221 is 45 degrees, the angle can adapt to the natural optimal tin climbing angle formed by the surface tension when the solder paste is melted, and the stability is achieved. The welding section 322 is welded with the bonding pad 20 by the three welding surfaces 3221, so that the welding area is increased, the welding strength is improved, and the stress is more uniform by welding a plurality of surfaces. During reflow soldering, the wetting force generated when the solder paste wets the element soldering surface only acts on the soldering surface 3221, so that the outer side wall of the soldering segment 322 is not subjected to the wetting force, the phenomenon that the LED31 tilts up by taking the bending point of the pin 32 as a fulcrum is avoided, and the LED31 is prevented from being inclined during soldering. The bonding surface 3222 is bonded to the pad 20, so that stability is further improved, and thus, not only is welding strength ensured, but also stability during welding is ensured.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the scope of the present invention, and any modifications, equivalents or improvements that are within the spirit of the present invention are intended to be covered by the following claims.

Claims

1. The utility model provides a booth of high strength is apart from LED welded structure which characterized in that: the high-strength small-spacing LED welding structure comprises a circuit board, at least four welding pads arranged on the circuit board, an LED arranged on the welding pads, and at least four solder pastes connected with the LED and the welding pads, wherein the LED comprises a body and at least four pins arranged on the body, the pins comprise a connecting section connected with the body and a welding section connected with the welding pads, one end of the connecting section is connected with the body, the other end of the connecting section is connected with the welding section, the welding section comprises three adjacent welding faces connected with the solder pastes and an attaching face attached to the welding pads, the welding faces and the edges of the welding pads are arranged at intervals, the distance between the edges of the welding pads and the welding faces is equal to the height of the welding sections, and the plane of the attaching face is perpendicular to the plane of the welding faces and attached to the welding pads, the solder paste is connected the welding face with the pad is being followed on the cross-section of welding section's center pin the solder paste is right triangle and two right-angle sides's length equals, the inclined plane of solder paste with the contained angle between the place plane of welding face is 45 degrees.

2. The high strength, small pitch LED bonding structure of claim 1, wherein: at least two pins are arranged on each side of the body.

3. The high strength, small pitch LED bonding structure of claim 1, wherein: the plane of the welding section is parallel to the plane of the bonding pad.

4. The high strength, small pitch LED bonding structure of claim 1, wherein: the lengths of the two right-angle sides of the solder paste are equal on the section along the central axis of the welding section.

5. The high strength, small pitch LED bonding structure of claim 1, wherein: the pins are integrally formed, and are L-shaped, and the opening direction of the pins faces the body.