CN213425006U

CN213425006U - LED packaging structure

Info

Publication number: CN213425006U
Application number: CN202021954540.0U
Authority: CN
Inventors: 马志华
Original assignee: Shenzhen Lepower Opto Electronics Co ltd
Current assignee: Shenzhen Lepower Opto Electronics Co ltd
Priority date: 2020-09-09
Filing date: 2020-09-09
Publication date: 2021-06-11
Anticipated expiration: 2030-09-09

Abstract

The utility model discloses a LED packaging structure, include: the base plate, positive pad and reverse side pad, positive pad sets up in the front of base plate, reverse side pad sets up the reverse side at the base plate, positive pad is connected with reverse side pad electricity, enclose the frame spare, set up in the front of base plate, it is cyclic annular to enclose the frame spare, it sets up around positive pad to enclose the frame spare, it sets up with positive pad interval to enclose the frame spare, it is equipped with the welded layer on the frame spare to enclose, the chip, be fixed in on the positive pad, the closing cap, the surface that is close to enclosing the frame spare is equipped with the metal level, metal level and welded layer fixed connection, so that the closing cap. The utility model discloses, through the direct and closing cap welding of welding layer, effectual unable secondary high temperature reflow soldering when having solved the LED encapsulation does not have the encapsulation of organic matter simultaneously, also can not receive illumination influence and lead to the closing cap to drop easily.

Description

LED packaging structure

Technical Field

The utility model relates to a LED encapsulates technical field, especially relates to a LED packaging structure.

Background

The LED ultraviolet light on the market is also called uv LED and is divided into uv-a LED, uv-b LED, uv-c LED and uv-c LED. However, some organic adhesives are used for the packaging of the ultraviolet LED, and the organic adhesives have a problem that the ultraviolet light irradiation easily causes organic failure, so that the quartz glass or other sealing covers of the packaging are peeled off, and the problem can not be effectively solved.

SUMMERY OF THE UTILITY MODEL

In view of the above, it is necessary to provide an LED package structure.

There is provided an LED package structure including,

a substrate;

the front bonding pad is arranged on the front side of the substrate, the back bonding pad is arranged on the back side of the substrate, and the front bonding pad is electrically connected with the back bonding pad;

the surrounding frame piece is arranged on the front side of the substrate and is annular, the surrounding frame piece is arranged around the front side bonding pad and is arranged at an interval with the front side bonding pad, and a welding layer is arranged on the surrounding frame piece;

the chip is fixed on the front bonding pad;

and the surface of the sealing cover, which is close to the surrounding frame piece, is provided with a metal layer, and the metal layer is fixedly connected with the welding layer so that the sealing cover is fixed on the surrounding frame piece.

The substrate is provided with a through hole, conductive metal is filled in the through hole, the front surface pad and the back surface pad are respectively fixed on the two sides of the front surface and the back surface of the conductive metal, and the front surface pad and the back surface pad are respectively electrically connected with the conductive metal.

The through holes are arranged in pairs, and the front bonding pads are provided with welding holes matched with the through holes, and the welding holes are arranged in pairs.

Wherein the metal layer is a gold layer, and the thickness of the gold layer is 0.01-0.1 μm.

Wherein, the welding layer is tin-antimony alloy tin paste or reinforced tin paste.

The front surface bonding pad comprises a first bonding pad, and the chip is fixed on the first bonding pad.

The front bonding pad further comprises a second bonding pad, the first bonding pad and the second bonding pad are arranged on the front surface of the substrate at intervals, and the chips are fixed on the first bonding pad and the second bonding pad respectively.

The chip comprises a UV chip and a diode, the UV chip is located in the center area of the rectangle formed by splicing the first bonding pad and the second bonding pad, and the diode is located in the edge area of the rectangle formed by splicing the first bonding pad and the second bonding pad.

Wherein, the UV chip is flip UV chip, flip UV chip one side set up in on the first pad, flip UV chip another side set up in on the second pad.

Wherein the first bonding pad and the second bonding pad are both rectangular.

Adopt the embodiment of the utility model provides a, following beneficial effect has: the utility model discloses a welding layer is direct will enclose frame spare and closing cap welding together, does not have any organic fixed connection, and the effectual LED encapsulation of having solved can not receive illumination influence and lead to the closing cap to take off easily.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Wherein:

fig. 1 is a schematic view of an LED package structure according to an embodiment of the present invention;

fig. 2 is a cross-sectional view a-a of the LED package structure shown in fig. 1.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

Referring to fig. 1 and 2, an LED package structure is provided, which includes a substrate 10, a front pad 20, a back pad 30, a frame 40, a chip 50, a cover 70, the front pad 20 and the back pad 30, wherein the front pad 20 is disposed on the front side of the substrate 10, the back pad 30 is disposed on the back side of the substrate 10, the front pad 20 is electrically connected to the back pad 30, and the back pad 30 is a heat conducting pad, which functions as heat conduction. This type of packaging is called thermoelectric separation, which has many advantages, mainly due to the thermal design of the LED. Enclose frame 40, set up in the front of base plate 10, enclose frame 40 and be cyclic annular, enclose frame 40 and set up around front pad 20, enclose frame 40 and front pad 20 interval setting, be equipped with welding layer 50 on enclosing frame 40, chip 60 is fixed in on the front pad 20, closing cap 70, the surface that is close to enclosing frame 40 is equipped with the metal layer, metal layer and welding layer 50 fixed connection to make closing cap 70 be fixed in on enclosing frame 40.

In this embodiment, the substrate 10 may be an aluminum nitride substrate or an aluminum oxide substrate, the cap 70 is a metalized cap made of quartz glass or sapphire glass, and the cap 70 may have a planar structure or a 3D angled structure. The quartz glass metalized sealing cover 70 is formed by performing surface metallization processing on planar quartz glass, attaching a layer of kovar metal to the surface of the quartz glass, wherein the kovar metal is 5-200 μm thick, the kovar metal can be a mixture of silver paste and glass powder, is attached to the surface of the quartz glass through screen printing, and is sintered at the high temperature of 600-1400 ℃, so that the effect of surface metallization of the quartz glass is achieved, and an effective carrier is provided for subsequent fixed connection with the surrounding frame piece 40.

Wherein, the thickness of the whole surface of the sealing cover 70 is 0.1 μm-0.5 μm, and the sealing cover 70 is metallized first. A whole piece of quartz glass or sapphire glass is firstly cleaned by ultrasonic clear water, silk-screen printing silver paste and a glass powder layer are used for 8-12 microns at the corresponding welding position of the glass, the first curing is carried out at the low temperature of 150 ℃ and 200 ℃, then the printing is carried out at the same position, then the high-temperature co-firing is carried out by a ceramic sintering furnace, the co-firing temperature is 550-750 ℃, the time is about 0.5H-2H, the silk-screen printing twice is used for improving the adhesive force of the silver paste on the glass, the welding of the sealing cover 40 and the substrate 10 can be obviously improved, the glass is prevented from falling in the welding process, in the embodiment, an aluminum nitride substrate is taken as an example, the aluminum nitride can be manufactured by a bare plate with the thickness of 0.38mm or 0.5mm, and upper and lower surface circuit copper layers.

The surrounding frame member 40 is made of general copper alloy metal, the height of the surrounding dam is determined according to the height of the wafer, and is usually between 0.4 mm and 0.55mm, a gold layer is plated on the surface of the copper alloy metal frame, the plating thickness is between 0.1 μm and 0.9 μm, the surrounding frame member 40 can also be metal such as copper, copper alloy, gold, silver and the like, or a non-ferrous metal frame body after surface plating, or a ceramic surrounding frame member 40 with a copper layer plated at the bottom.

The utility model discloses be inorganic matter or metal in all materials and the process, do not have organic matter composition, so the encapsulation utility model discloses a full inorganic packaging technology, the encapsulation of solution ultraviolet UVC LED that can be perfect meets the illumination and easily takes place the problem that the closing cap 70 drops.

As shown in fig. 1 and 2, through

holes

12 and 13 are formed in the substrate 10, conductive metal is filled in the through

holes

12 and 13, the front pads 20 and the back pads 30 are respectively fixed on both sides of the front and back surfaces of the conductive metal, and the front pads 20 and the back pads 30 are respectively electrically connected to the conductive metal. The through

holes

12 and 13 are arranged in pairs, and the front pad 20 is provided with welding holes matched with the through

holes

12 and 13, and the welding holes are arranged in pairs. Accordingly, an electrode pair is formed on the reverse land, and this packaging method is called thermoelectric separation.

Preferably, the front surface bonding pad 20 includes a first bonding pad 21, the chip 60 is fixed on the first bonding pad 21, the front surface bonding pad 20 further includes a second bonding pad 22, the first bonding pad 21 and the second bonding pad 22 are disposed on the substrate 10 at an interval, and the chip 60 is fixed on the first bonding pad 21 and the second bonding pad 22, respectively. The number of the first pads 21 may be one or more, and is not limited, which is also required according to the actual use situation.

Preferably, the metal layer is a gold layer having a thickness of 0.01 μm to 0.1 μm. The solder layer 50 is tin-antimony alloy paste or reinforced solder paste. The metal layer can also be a copper layer, an aluminum layer, a silver layer and other metal layers, and the thickness of different gold layers is different. The tin-antimony alloy solder paste or the reinforced solder paste can be other tin-antimony alloys such as tin-antimony alloy solder sheet, gold-tin alloy solder paste, gold-tin alloy solder sheet and the like, the melting point of the tin-antimony alloy is 245-255 ℃, the melting point of the reinforced solder paste is about 270 ℃, and the poor ultraviolet LED caused by reflow soldering of the high-temperature solder paste again in the application process can be avoided through reflow soldering of the high-temperature solder paste again.

Preferably, the front surface pads 20 include first pads 21, and the chip 60 is fixed on the first pads 21. If the pad has only the first pad 21, the chip 60 is fixed to the first pad 21. The front bonding pad 21 further includes a second bonding pad 22, the first bonding pad 21 and the second bonding pad 22 are disposed on the front surface of the substrate 10 at an interval, and the chip 60 is fixed on the first bonding pad 21 and the second bonding pad 22, respectively.

Preferably, the chip 60 includes a UV chip 61 and a diode 62, the UV chip 61 is located in a central region where the first pad 21 and the second pad 22 are spliced to form a rectangle, and the diode 62 is located in an edge region where the first pad 21 and the second pad 22 are spliced to form a rectangle. The first pad 21 and the second pad 22 may be formed in a rectangular shape, but may be formed in other shapes such as a circular shape, an oval shape, a triangular shape, a hexagonal shape, and a trapezoidal shape.

Preferably, the UV chip 61 is a flip UV chip, one side of which is disposed on the first pads 21 and the other side of which is disposed on the second pads 22. The back bonding pad of the flip chip is treated by a gold-tin layer, soldering paste serving as die attach adhesive is used for die attach, the flip chip UVC chip and the diode are fixed on the die attach bonding pad 4 dipped with the soldering paste, the temperature of the common eutectic furnace is gradually increased in 4 sections, the time of each section of temperature is 30-100S, and the highest temperature zone is about 310-340 ℃. The eutectic is completed. The fixing of the inverted UVC wafer and the diode is firmer.

Preferably, the first pad 21 and the second pad 22 are rectangular. Of course, the first pad 21 and the second pad 22 may have other matching shapes, such as a semi-circle.

The above disclosure 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 invention, which is defined by the appended claims.

Claims

1. An LED package structure, comprising:

a substrate;

the chip is fixed on the front bonding pad;

2. The LED package structure of claim 1, wherein a through hole is formed in the substrate, the through hole is filled with a conductive metal, the front pad and the back pad are respectively fixed on two sides of the front surface and the back surface of the conductive metal, and the front pad and the back pad are respectively electrically connected to the conductive metal.

3. The LED package structure of claim 2, wherein the through holes are arranged in pairs, and the front pad has solder holes matching the through holes, and the solder holes are arranged in pairs.

4. The LED package structure of claim 1, wherein the metal layer is a gold layer having a thickness of 0.01-0.1 μm.

5. The LED package structure of claim 1, wherein the solder layer is a tin-antimony alloy solder paste or a reinforced solder paste.

6. The LED package structure of any of claims 1-5, wherein the front side bonding pad comprises a first bonding pad, and the chip is fixed on the first bonding pad.

7. The LED package structure of claim 6, wherein the front bonding pad further comprises a second bonding pad, the first bonding pad and the second bonding pad are disposed on the front surface of the substrate at an interval, and the chip is fixed on the first bonding pad and the second bonding pad respectively.

8. The LED package structure of claim 7, wherein the chip comprises a UV chip and a diode, the UV chip is located in a central region where the first pad and the second pad are spliced to form a rectangle, and the diode is located in an edge region where the first pad and the second pad are spliced to form a rectangle.

9. The LED package structure of claim 8, wherein the UV chip is a flip UV chip, one side of the flip UV chip is disposed on the first bonding pad, and the other side of the flip UV chip is disposed on the second bonding pad.

10. The LED package structure of claim 9, wherein the first and second pads are each rectangular.