阅读说明：本技术 一种led封装结构 (LED packaging structure ) 是由 周建华 易巨荣 张振强 于 2020-12-16 设计创作，主要内容包括：本发明涉及LED加工技术领域,公开了一种LED封装结构,包括设置有至少一个第一晶片的正极焊盘、设置有至少一个第二晶片的负极焊盘和分隔支架的晶片支架,正极焊盘的面积与负极焊盘的面积不相等,第一晶片与正极焊盘通过第一焊线连接,第一晶片与第二晶片通过第二焊线连接,第三晶片与负极焊盘通过第三焊线连接,焊线包括第一焊球、第一弧段、第二弧段、第三弧段、第四弧段和第二焊球,且焊线在俯视状态下为“J”形；焊线在侧视状态下,第一弧段朝远离第二焊球的方向凸起,第二弧段向下凹陷,第三弧段向上凸起,第四弧段向下凹陷。本发明能够有效分散、缓冲焊线的三维应力,提高焊线的抗冷热冲击能力与耐拉扯能力,提高散热效果。(The invention relates to the technical field of LED processing, and discloses an LED packaging structure which comprises an anode bonding pad provided with at least one first wafer, a cathode bonding pad provided with at least one second wafer and a wafer support for separating the support, wherein the area of the anode bonding pad is not equal to that of the cathode bonding pad, the first wafer is connected with the anode bonding pad through a first welding wire, the first wafer is connected with the second wafer through a second welding wire, the third wafer is connected with the cathode bonding pad through a third welding wire, the welding wire comprises a first welding ball, a first arc section, a second arc section, a third arc section, a fourth arc section and a second welding ball, and the welding wire is in a J shape in a overlooking state; the bonding wire is at the side view state, and first segmental arc is protruding towards the direction of keeping away from the second solder ball, and the second segmental arc is sunken downwards, and the third segmental arc is upwards protruding, and the fourth segmental arc is sunken downwards. The invention can effectively disperse and buffer the three-dimensional stress of the welding wire, improve the cold and hot impact resistance and the pulling resistance of the welding wire and improve the heat dissipation effect.)

1. An LED packaging structure is characterized by comprising a wafer support, wherein the wafer support comprises a positive electrode bonding pad, a negative electrode bonding pad and a separation support for separating the positive electrode bonding pad from the negative electrode bonding pad, the area of the positive electrode bonding pad is not equal to that of the negative electrode bonding pad, at least one first wafer is arranged on the positive electrode bonding pad, at least one second wafer is arranged on the negative electrode bonding pad, the first wafer is connected with the positive electrode bonding pad through a first bonding wire, the first wafer is connected with the second wafer through a second bonding wire, the third wafer is connected with the negative electrode bonding pad through a third bonding wire, the first welding wire, the second welding wire and the third welding wire comprise a first welding ball, a first arc section, a second arc section, a third arc section, a fourth arc section and a second welding ball which are sequentially connected, and the linear type of the welding wire is integrally J-shaped in a top view state; in a side view state of the wire type of the bonding wire, the first arc section protrudes towards a direction far away from the second solder ball, the second arc section is downwards concave, the third arc section protrudes upwards, and the fourth arc section is downwards concave.

2. The LED package structure of claim 1, wherein said first arc segment projects half of a position of said first solder ball away from said second solder ball.

3. The LED package structure of claim 1, wherein the second arc segment is recessed downward by 2-3 wire diameter positions of the second arc segment.

4. The LED package structure of claim 3, wherein the third arc segment protrudes upwards by 2-3 wire diameters of the third arc segment.

5. The LED package structure of claim 1, wherein a transition section is connected between the first solder ball and the first arc section, the transition section extending upward from the first solder ball and smoothly transitioning with the first arc section.

6. The LED package structure of claim 1, wherein the first wire bond, the second wire bond, and the third wire bond are metal lines.

7. The LED package structure of claim 1, wherein a first die is disposed on the positive bonding pad, two second dies are disposed on the negative bonding pad, two adjacent second dies are connected by a fourth bonding wire, and the fourth bonding wire has a structure identical to that of the first bonding wire.

8. The LED package structure of claim 7, wherein the first solder ball of the first wire is bonded to the negative electrode of the first die, the second solder ball of the first wire is bonded to the positive electrode pad, the first solder ball of the second wire is bonded to the positive electrode of the first die, the second solder ball of the second wire is bonded to the negative electrode of the second die adjacent to the separation frame, the first solder ball of the fourth wire is bonded to the positive electrode of the second die adjacent to the separation frame, the second solder ball of the fourth wire is bonded to the negative electrode of the second die away from the separation frame, the first solder ball of the third wire is bonded to the positive electrode of the second die away from the separation frame, and the second solder ball of the third wire is bonded to the negative electrode pad.

9. The LED package structure of claim 1, wherein two first dies are disposed on the positive bonding pad, one second die is disposed on the negative bonding pad, two adjacent first dies are connected by a fifth bonding wire, and the structure of the fifth bonding wire is the same as that of the first bonding wire.

10. The LED package structure of claim 9, wherein the first solder ball of the first wire is bonded to the negative electrode of the first die away from the separation frame, the second solder ball of the first wire is bonded to the positive electrode pad, the first solder ball of the fifth wire is bonded to the positive electrode of the first die away from the separation frame, the second solder ball of the fifth wire is bonded to the negative electrode of the first die adjacent to the separation frame, the first solder ball of the second wire is bonded to the positive electrode of the first die adjacent to the separation frame, the first solder ball of the second wire is bonded to the negative electrode of the second die, the first solder ball of the third wire is bonded to the positive electrode of the second die, and the second solder ball of the third wire is bonded to the negative electrode pad.

Technical Field

The invention relates to the technical field of LED processing, in particular to an LED packaging structure.

Background

The LED is used as a novel light source, has the advantages of low energy consumption, no pollution, small size, convenience and flexibility in use and the like, and is widely applied to various fields; in the existing LED packaging technology, in order to achieve a higher luminous effect and meet the requirements of customer products, a packaging mode of connecting multiple wafers in series is adopted, usually, a plurality of wafers are only arranged on a negative electrode bonding pad or a positive electrode bonding pad, and the wafers are connected through thin metal wires to form an electric path, so that the situation that the heat on a single bonding pad is too high and the heat is difficult to dissipate in time is easily caused, further, the light conversion efficiency is poor, and the service life of the LED is reduced; the bonding wire is a very important link in LED production, and the LED bracket and a wafer electrode are welded through a metal thin wire, so that the wafer is electrically connected with the outside to enable the wafer to emit light. In the process of welding the wire, the welding wire expands with heat and contracts with cold due to the physical property of the welding wire, and the existing welding wire is relatively straight, so that the welding wire is pulled under the action of cold and heat shock and external force, stress is generated in the welding wire, and the welding wire and the welding point are easily broken to cause the lamp to be dead.

Disclosure of Invention

The invention aims to provide an LED packaging structure which can effectively disperse and buffer the three-dimensional stress of a bonding wire, improve the heat dissipation effect, improve the cold and hot impact resistance and the pulling resistance of the bonding wire and prolong the service life.

In order to achieve the above object, the present invention provides an LED package structure, comprising a die pad, the wafer support comprises a positive electrode bonding pad, a negative electrode bonding pad and a separation support for separating the positive electrode bonding pad from the negative electrode bonding pad, the area of the positive electrode bonding pad is not equal to that of the negative electrode bonding pad, at least one first wafer is arranged on the positive electrode bonding pad, at least one second wafer is arranged on the negative electrode bonding pad, the first wafer is connected with the positive electrode bonding pad through a first bonding wire, the first wafer is connected with the second wafer through a second bonding wire, the third wafer is connected with the negative electrode bonding pad through a third bonding wire, the first welding wire, the second welding wire and the third welding wire comprise a first welding ball, a first arc section, a second arc section, a third arc section, a fourth arc section and a second welding ball which are sequentially connected, and the linear type of the welding wire is integrally J-shaped in a top view state; in a side view state of the wire type of the bonding wire, the first arc section protrudes towards a direction far away from the second solder ball, the second arc section is downwards concave, the third arc section protrudes upwards, and the fourth arc section is downwards concave.

As a preferable aspect of the present invention, the first arc segment protrudes by half the position of the first solder ball in a direction away from the second solder ball.

Preferably, the second arc segment is recessed downwards by 2-3 positions of the line diameter of the second arc segment.

Preferably, the third arc segment protrudes upwards by 2-3 positions of the wire diameter of the third arc segment.

As a preferred aspect of the present invention, a transition section is connected between the first solder ball and the first arc section, and the transition section extends upward from the first solder ball and is in smooth transition with the first arc section.

As a preferable aspect of the present invention, the first bonding wire, the second bonding wire, and the third bonding wire are metal wires.

As a preferable scheme of the present invention, a first wafer is disposed on the positive electrode bonding pad, two second wafers are disposed on the negative electrode bonding pad, two adjacent second wafers are connected by a fourth bonding wire, and a structure of the fourth bonding wire is the same as that of the first bonding wire.

As a preferable aspect of the present invention, the first solder ball of the first bonding wire is welded to the negative electrode of the first wafer, the second solder ball of the first bonding wire is welded to the positive electrode pad, the first solder ball of the second bonding wire is welded to the positive electrode of the first wafer, the second solder ball of the second bonding wire is welded to the negative electrode of the second wafer of the negative electrode pad adjacent to the separation bracket, the first solder ball of the fourth bonding wire is welded to the positive electrode of the second wafer adjacent to the separation bracket, the second solder ball of the fourth bonding wire is welded to the negative electrode of the second wafer far from the separation bracket, the first solder ball of the third bonding wire is welded to the positive electrode of the second wafer far from the separation bracket, and the second solder ball of the third bonding wire is welded to the negative electrode pad.

As a preferable scheme of the present invention, two first dies are disposed on the positive electrode bonding pad, one second die is disposed on the negative electrode bonding pad, two adjacent first dies are connected by a fifth bonding wire, and a structure of the fifth bonding wire is the same as that of the first bonding wire.

As a preferable aspect of the present invention, the first solder ball of the first bonding wire is soldered to the negative electrode of the first chip far from the separation bracket, the second solder ball of the first bonding wire is soldered to the positive electrode pad, the first solder ball of the fifth bonding wire is soldered to the positive electrode of the first chip far from the separation bracket, the second solder ball of the fifth bonding wire is soldered to the negative electrode of the first chip adjacent to the separation bracket, the first solder ball of the second bonding wire is soldered to the positive electrode of the first chip adjacent to the separation bracket, the first solder ball of the second bonding wire is soldered to the negative electrode of the second chip, the first solder ball of the third bonding wire is soldered to the positive electrode of the second chip, and the second solder ball of the third bonding wire is soldered to the negative electrode pad.

Compared with the prior art, the LED packaging structure provided by the embodiment of the invention has the beneficial effects that:

in the embodiment of the invention, the wire type of the welding wire is integrally J-shaped in an overlooking state, the damage of a ceramic nozzle to the welding wire in the welding wire process can be reduced, the first arc is in a convex state and can buffer the stress of the welding wire in the vertical direction and the longitudinal direction, the continuous wave band formed by matching the second arc section and the third arc section is in a non-tightening state and can buffer the stress of the welding wire in the longitudinal direction and the transverse direction, the welding wire can be more smoothly transited to the second welding ball through the fourth arc section, the change damage between the tail end of the welding wire and the second welding ball is reduced, and the improvement of the pulling force and the pushing force of the second welding ball is; in addition, the at least one wafer is arranged on the anode bonding pad and the cathode bonding pad respectively, and the wafers can be arranged in a dispersed manner, so that the heat dissipation effect is improved, the light efficiency is improved, and the service life of the LED lamp is prolonged; therefore, the invention can effectively disperse and buffer the three-dimensional stress of the welding wire in the vertical direction, the horizontal direction and the longitudinal direction, avoid the stress buffer dead angle, improve the cold and hot impact resistance and the pulling resistance of the welding wire, improve the yield of the LED, improve the heat dissipation effect and prolong the service life of the LED.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly described below.

Fig. 1 is a schematic structural diagram of an LED package structure provided in the present invention;

FIG. 2 is a schematic structural diagram of another LED package structure provided by the present invention;

FIG. 3 is a front view of a first wire arc;

FIG. 4 is a top view of a first wire arc;

in the figure, 1 is a wafer holder; 11 is a positive electrode pad; 12 is a negative electrode bonding pad; 13 is a separation bracket; 2 is a first wafer; 3 is a second wafer; 4 is a first bonding wire; 41 is a first solder ball; 42 is a first arc segment; 43 is a second arc segment; 44 is a third arc segment; 45 is a fourth arc segment; 46 is a second solder ball; 47 is a transition section; 5 is a second bonding wire; 6 is a third bonding wire; 7 is a fourth bonding wire; and 8 is a fifth bonding wire.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

As shown in fig. 1 to 4, an LED package structure according to a preferred embodiment of the present invention includes a wafer support 1, where the wafer support 1 includes an anode pad 11, a cathode pad 12, and a separation support 13 for separating the anode pad 11 from the cathode pad 12, an area of the anode pad 11 is not equal to an area of the cathode pad 12, at least one first wafer 2 is disposed on the anode pad 11, at least one second wafer 3 is disposed on the cathode pad 12, the first wafer 2 is connected to the anode pad 11 by a first bonding wire 4, the first wafer 2 is connected to the second wafer 3 by a second bonding wire 5, the third wafer is connected to the cathode pad 12 by a third bonding wire 6, and the first bonding wire 4, the second bonding wire 5, and the third bonding wire 6 include a first solder ball 41, a second solder ball, and a third solder ball connected in sequence, The welding wire comprises a first arc section 42, a second arc section 43, a third arc section 44, a fourth arc section 45 and a second welding ball 46, wherein the wire type of the welding wire is integrally J-shaped in a top view state; in the wire bonding pattern, in a side view, the first arc section 42 is convex in a direction away from the second solder ball 46, the second arc section 43 is concave downward, the third arc section 44 is convex upward, and the fourth arc section 45 is concave downward. It should be noted that the top view direction is a direction perpendicular to the plane of the bonding pad, and the side view direction is shown as a direction in fig. 1; the vertical direction is the Z direction in fig. 3, the horizontal direction is the X direction in fig. 3, and the vertical direction is the Y direction in fig. 4.

It can be seen that the wire type of the bonding wire in the embodiment of the present invention is overall "J" shape in a top view state, which can reduce the damage of the ceramic nozzle to the bonding wire in the bonding wire process, and the first arc is a convex state, which can buffer the stress of the bonding wire in the vertical and longitudinal directions, and the continuous wave band formed by the matching of the second arc section 43 and the third arc section 44 is in a non-tight state, which can buffer the stress of the bonding wire in the longitudinal and transverse directions, and the bonding wire can be more smoothly transited to the second solder ball 46 through the fourth arc section 45, so as to reduce the variation damage between the tail end of the bonding wire and the second solder ball 46, which is helpful to improve the pulling force and pushing force of; in addition, at least one wafer is arranged on the anode bonding pad 11 and the cathode bonding pad 12 respectively, and the wafers can be arranged in a dispersed manner, so that the heat dissipation effect is improved, the light efficiency is improved, and the service life of the LED lamp is prolonged; therefore, the invention can effectively disperse and buffer the three-dimensional stress of the welding wire in the vertical direction, the horizontal direction and the longitudinal direction, avoid the stress buffer dead angle, improve the cold and hot impact resistance and the pulling resistance of the welding wire, improve the yield of the LED, improve the heat dissipation effect and prolong the service life of the LED.

It should be further noted that the first chip 2, the second chip 3, the first bonding wire 4, the second bonding wire 5, and the third bonding wire 6 are all coated with LED glue.

Illustratively, the first arc section 42 protrudes by half the first solder ball 41 in the direction away from the second solder ball 46, so that the vertical and longitudinal stresses on the bonding wire caused by thermal expansion and contraction of the bonding wire and the thermal expansion and contraction of the LED glue during operation can be effectively buffered.

Illustratively, the second arc segments 43 are recessed downwards at the positions of 2-3 wire diameters of the second arc segments 43; the third arc section 44 protrudes upwards for 2-3, and the position of the line diameter of the third arc section 44 can effectively buffer the vertical and transverse stress of the bonding wire generated by expansion with heat and contraction with cold of the bonding wire and expansion with heat and contraction with cold of the LED glue during working.

Illustratively, a transition section 47 is connected between the first solder ball 41 and the first arc section 42, the transition section 47 extends upward from the first solder ball 41 and smoothly transitions with the first arc section 42, and by providing the transition section 47, the first arc can be buffered, so that the first arc is prevented from being broken due to the fact that the first arc is directly bent from the first solder ball 41, and thus the reliability of the LED package structure is improved.

Illustratively, the first bonding wire 4, the second bonding wire 5 and the third bonding wire 6 are metal wires, which may be gold wires, silver wires, copper wires or alloy wires; in the present embodiment, the first bonding wire 4, the second bonding wire 5, and the third bonding wire 6 are preferably gold wires, which can ensure good conductivity of the bonding wires, and have high stability, are not easy to age, and prolong the service life of the LED.

It should be noted that, when two or more second chips 3 are provided, the adjacent second chips 3 are connected by a fourth bonding wire 7, and the structure and material of the fourth bonding wire 7 are the same as those of the first bonding wire 4. When two or more first chips 2 are arranged, the adjacent first chips 2 are connected through a fifth welding line, and the structure and the material of the fifth welding line are the same as those of the first welding line 4.

Taking a three-crystal LED bead as an example, as shown in fig. 1, a first wafer 2 is disposed on the positive electrode bonding pad 11, two second wafers 3 are disposed on the negative electrode bonding pad 12, the first wafer 2 and the second wafer 3 are disposed in a staggered manner, a first solder ball 41 of the first bonding wire 4 is welded to the negative electrode of the first wafer 2, a second solder ball 46 of the first bonding wire 4 is welded to the positive electrode bonding pad 11, a first solder ball of the second bonding wire 5 is welded to the positive electrode of the first wafer 2, a second solder ball of the second bonding wire 5 is welded to the negative electrode of the second wafer 3 of the negative electrode bonding pad 12 adjacent to the separation support 13, a first solder ball of the fourth bonding wire 7 is welded to the positive electrode of the second wafer 3 adjacent to the separation support 13, a second solder ball of the fourth bonding wire 7 is welded to the negative electrode of the second wafer 3 far from the separation support 13, and a first solder ball of the third bonding wire 6 is welded to the positive electrode of the second wafer 3 far from the separation support 13 And the second welding balls of the third welding wires 6 are welded on the cathode bonding pads 12, and wafers can be dispersedly arranged on the anode bonding pads 11 and the cathode bonding pads 12, so that the heat dissipation effect is improved, the light efficiency is improved, and the service life of the LED lamp is prolonged. Specifically, the end of the fourth arc segment 45 of the first bonding wire 4 extends downward and is close to the positive electrode bonding pad 11, the end of the fourth arc segment of the second bonding wire 5 extends downward and is close to the second wafer 3 adjacent to the separation support 13, the end of the fourth arc segment of the fourth bonding wire 7 extends downward and is close to and away from the second wafer 3 of the separation support 13, and the end of the fourth arc segment of the third bonding wire 6 extends downward and is close to the negative electrode bonding pad 12, so that the change damage between the end of the bonding wire and the second bonding ball 46 is effectively reduced.

As shown in fig. 2, in another embodiment, two first dies 2 are disposed on the positive electrode bonding pad 11, one second die 3 is disposed on the negative electrode bonding pad 12, the first dies 2 and the second dies 3 are disposed in parallel, two adjacent first dies 3 are connected by a fifth bonding wire 8, and the structure of the fifth bonding wire 8 is the same as that of the first bonding wire 4; the first solder ball 41 of the first bonding wire 4 is soldered on the negative electrode of the first chip 3 far away from the separation bracket 13, the second solder ball 46 of the first bonding wire 4 is soldered on the positive electrode bonding pad 11, the first solder ball of the fifth bonding wire 8 is soldered on the positive electrode of the first chip 2 far away from the separation bracket 13, the second solder ball of the fifth bonding wire 8 is soldered on the negative electrode of the first chip 2 adjacent to the separation bracket 13, the first solder ball of the second bonding wire 5 is soldered on the positive electrode of the first chip 2 adjacent to the separation bracket 13, the first solder ball of the second bonding wire 5 is soldered on the negative electrode of the second chip 2, the first solder ball of the third bonding wire 6 is soldered on the positive electrode of the second chip 3, the second solder ball of the third bonding wire 6 is soldered on the negative electrode bonding pad 12, and the chips can be dispersedly arranged on the positive electrode bonding pad 11 and the negative electrode bonding pad 12, thereby improving the heat dissipation effect and further improving the lighting effect and prolonging the service life of the LED lamp.

It should be noted that the number of wafers on the wafer support 1 can be set as desired, the number of the first wafers 2 on the positive electrode pads 11 and the number of the second wafers 3 on the negative electrode pads 12 can be matched as desired, the area of the positive electrode pads 11 can be adjusted according to the number of the first wafers 2, and the area of the negative electrode pads 12 can be adjusted according to the number of the second wafers 3.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "connected" and "connected" are to be interpreted broadly, e.g., as being fixed or detachable or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions should also be regarded as the protection scope of the present invention.