CN215008265U

CN215008265U - LED packaging assembly

Info

Publication number: CN215008265U
Application number: CN202023287575.6U
Authority: CN
Inventors: 张汉春; 江忠永
Original assignee: Hangzhou Multi Color Optoelectronics Co ltd
Current assignee: Hangzhou Multi Color Optoelectronics Co ltd
Priority date: 2020-12-30
Filing date: 2020-12-30
Publication date: 2021-12-03
Anticipated expiration: 2030-12-30

Abstract

The application discloses LED encapsulation subassembly includes: a lead frame having a carrier pad, a plurality of leads spaced apart from one another, and a plurality of external pads; the first LED element, the second LED element and the third LED element are fixed on the bearing pad of the lead frame and are electrically connected with the bearing pad and the pins; and an encapsulant for covering the lead frame and allowing light to pass therethrough; a plurality of first conductive holes positioned at corners of the lead frame to electrically connect the plurality of pins with the plurality of external pads, respectively; the bearing pad is separated from the plurality of pins and comprises extension regions serving as the pins; the plurality of pins are electrically connected with the plurality of external bonding pads through first conductive holes at corresponding corners of the lead frame respectively; and the second conductive hole is positioned on the extension area of the bearing pad so as to electrically connect the bearing pad with the corresponding external bonding pad. This application will bear the weight of pad and outside pad intercommunication through the second electrically conductive hole, can adopt electroplating process to form the plating layer on the lead frame surface, reduce cost.

Description

LED packaging assembly

Technical Field

The present invention relates to LED packaging technology, and more particularly, to a LED package assembly for a LED display screen.

Background

The LED display screen has the following advantages: high gray scale, wide viewing angle, rich color, and customizable screen shape. Therefore, the LED display screen is widely used in various fields such as industry, traffic, commercial advertisement, information distribution, sports competition, and the like.

The pixel elements used in LED display screens are LEDs. The pixel element is, for example, an LED package component in a Surface Mounted Device (SMD) package manner. Each LED package assembly may include a lead frame, three LED elements respectively displaying three colors of red, green, and blue mounted on the lead frame, and a resin encapsulant covering the lead frame and allowing light to pass therethrough. The light emitting side of each of the three LED elements is the side covered by the packaging material. When displaying an image, the brightness of the three LED elements of each LED package assembly is controlled, so that full-color light emission can be realized with color mixing.

In the above-described LED package assembly, the LED is mounted on the lead frame. The lead frame is manufactured by a PCB manufacturing process, for example, and the surface of the metal layer of the lead frame can be plated with gold, silver and other noble metals to improve the conductivity. The lead frame has a carrier pad, a plurality of leads spaced apart from one another, and a plurality of external pads, the carrier pad and the plurality of leads being spaced apart from one another to implement an isolated island technique. The LED elements on the bearing pad are electrically connected with the plurality of pins through bonding wires. However, since the carrier pad and the plurality of leads are electrically isolated from each other, the surface of the carrier pad can only be plated by electroless gold plating, which is costly.

Therefore, it is desirable to further reduce the cost of plating the surface of the metal layer of the lead frame in the LED package.

SUMMERY OF THE UTILITY MODEL

In view of the above, it is an object of the present invention to provide an improved LED package assembly, which can form a plating layer on the surface of the metal layer of the lead frame by using a plating process through the second conductive via to connect the carrier pad and the back pad, thereby reducing the cost.

According to an aspect of the utility model, a provide a LED encapsulation subassembly, include: a lead frame having a carrier pad, a plurality of leads spaced apart from one another, and a plurality of external pads; a first LED element, a second LED element and a third LED element which are fixed on the bearing pad of the lead frame and are electrically connected with the bearing pad and the pins; and an encapsulant for covering the lead frame and allowing light to pass therethrough; a plurality of first conductive holes positioned at corners of the lead frame to electrically connect the plurality of pins with the plurality of external pads, respectively; wherein the carrier pad and the plurality of pins are spaced apart from each other, and the carrier pad includes an interconnection region electrically connected with the plurality of pins and an extension region as a pin; the plurality of pins are electrically connected with the plurality of external bonding pads through first conductive holes at corresponding corners of the lead frame respectively; and the second conductive hole is positioned on the extension area of the bearing pad so as to electrically connect the bearing pad with the corresponding external bonding pad.

Preferably, the LED package assembly further comprises: and a plurality of plating leads for forming a plating layer on the surface of the lead frame.

Preferably, the plurality of pins and the surface of the carrier pad comprise a plated layer.

Preferably, the plated leads are located on the first surface of the lead frame and connected to the extended regions of the carrier pad and/or the plurality of leads.

Preferably, the surfaces of the plurality of outer pads include a plating layer.

Preferably, the plated leads are located on the second surface of the lead frame and connected to the plurality of external pads.

Preferably, the extension region extends toward one corner of the lead frame and is spaced apart from the first conductive hole located at the corner.

Preferably, the first LED element, the second LED element and the third LED element include an anode electrode and a cathode electrode, respectively, the first LED element is a vertical chip, and the second LED element and the third LED element are front-mounted chips.

Preferably, the carrier pad is connected to an anode electrode or a cathode electrode of one of the first LED element, the second LED element and the third LED element.

Preferably, the anode electrode and the cathode electrode of the first LED element are formed on opposite surfaces, the cathode electrode of the first LED element being electrically connected to the carrier pad.

Preferably, anode electrodes of the first LED element, the second LED element, and the third LED element are commonly connected to a common pin among the plurality of pins.

Preferably, cathode electrodes of the first LED element, the second LED element and the third LED element are commonly connected to an extension region of the carrier pad.

Preferably, the first LED element, the second LED element, and the third LED element emit at least one of red light, green light, and blue light, respectively, and the arrangement order is not limited.

Preferably, the LED package assembly further comprises: a plurality of bonding wires, the first LED element, the second LED element, the third LED element being connected to the plurality of leads via respective ones of the plurality of bonding wires, respectively.

Preferably, the light emitting side of each of the first LED element, the second LED element and the third LED element is a side covered by the encapsulant.

Preferably, the first LED element is fixed on the carrier pad by using a conductive adhesive.

Preferably, the lead frame is a double-layer circuit board, the lead frame includes a PCB substrate, the bearing pad and the plurality of pins are located on a first surface of the PCB substrate, the plurality of external pads are located on a second surface of the PCB substrate, and the plurality of pins are electrically connected with the plurality of external pads through the first conductive holes between the first surface and the second surface, respectively.

Preferably, the interconnection region of the carrier pad comprises a first interconnection region, wherein the first LED element is located on the first interconnection region, the first interconnection region being connected to the extension region and to the corresponding external pad through a second conductive via.

Preferably, the second LED element and the third LED element are both located on the first interconnect region.

Preferably, the interconnection region of the carrier pad further comprises a second interconnection region spaced apart from the first interconnection region, the second LED element and the third LED element being located on the second interconnection region.

Preferably, the interconnection region of the carrier pad further comprises a second interconnection region and a third interconnection region spaced apart from the first interconnection region; the second and third LED elements are located on the second and third interconnect regions, respectively.

Preferably, the first LED element is a vertical chip.

Preferably, at least one of the plurality of leads has a shape of a truncated diamond that retains only one full corner, the full corner pointing towards the carrier pad, and the interconnect region is located at the top of the full corner.

According to the utility model discloses LED encapsulation subassembly, the second electrically conductive hole that bears the pad in the lead frame through the extension region is connected with an outside pad electricity at the back, can adopt electroplating process to form the plating layer, reduce cost on the metal level surface of lead frame.

Furthermore, the surface of the metal layer of the lead frame can be electroplated by utilizing the electroplating lead on the front surface or the back surface of the lead frame, so that the cost is reduced.

Furthermore, the bearing pad in the lead frame comprises an extension area used as a pin, the extension area does not need to extend to the corner of the PCB substrate in the lead frame, and the extension area only needs to extend to a position where the extension area can be electrically connected with an external bonding pad through the corresponding second conductive hole, so that the surface area of the bearing pad exposed on the bottom surface of the packaging material formed by packaging is reduced.

In a preferred embodiment, at least one of the leads has a shape of a diamond with a cut corner, which only has one complete corner, so that the surface area of the at least one lead exposed on the bottom surface of the encapsulation material of the encapsulation molding is reduced without increasing the length of the bonding wire.

The change of the shape of the lead frame and the change of the connection mode of the lead frame and the LED element obviously reduce the proportion of the metal surface of the lead frame in the bottom surface of the packaging material formed by packaging. When the LED element does not emit light, the reflection of the metal surface of the lead frame to the ambient light is correspondingly reduced, so that the contrast of the LED display screen is improved.

Further, the area of the lead frame bearing pad is reduced, and the shape of the lead frame bearing pad is regular, so that after packaging, the stress between the packaging material and the lead frame can be reduced, the stress is distributed uniformly, and the lead frame bearing pad is not easy to deform.

Furthermore, the bonding force between the packaging material and the PCB substrate is far greater than that between the packaging material and the gold and silver plating layers, so that the sealing property of the product can be improved.

Furthermore, the extension area of the bearing pad is directly electrically connected with the external bonding pad through the second conductive hole, so that the number of the internal bonding pads is reduced, the number of bonding wires is reduced, and the bonding wire efficiency is improved.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings.

Fig. 1 shows an exploded perspective view of a LED package assembly according to an embodiment of the present invention.

Fig. 2a and 2b show schematic plan views of a LED package assembly according to an embodiment of the invention, respectively;

fig. 3-7 respectively show exploded perspective views of LED package assemblies according to alternative embodiments of the present invention;

fig. 8 shows a flowchart of a method for manufacturing an LED package assembly according to an embodiment of the present invention.

Detailed Description

Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Like elements in the various figures are denoted by the same or similar reference numerals. For purposes of clarity, the various features in the drawings are not necessarily drawn to scale.

The present invention may be presented in a variety of forms, some of which are described below.

The LED package assembly 200 includes a lead frame 210, LED elements 220 to 240, and an encapsulant

250, wherein the LED elements 220 to 240 are mounted on the lead frame 210, and the encapsulant 250 is a light-transmitting material covering the surface of the lead frame 210. In the drawings, the encapsulant 250 of the package assembly 200 is shown separated from other parts for clarity.

The lead frame 210 is a two-layer wiring board manufactured by a PCB process, and includes a PCB substrate 217, a plurality of external pads 216, a carrier pad 211 (or referred to as a "die attach") and a plurality of leads 212. The plurality of leads 212 and the carrier pad 211 are located on the same side of the PCB substrate 217 and respectively opposite to the plurality of external pads 216 located on the other side of the PCB substrate 217, and the plurality of leads 212 and the corresponding plurality of external pads 216 are electrically connected through first conductive holes 218 in the PCB substrate 217. The first conductive via 218 is located at a corner of the lead frame 210.

The carrier pads 211 are used to provide mechanical support for the LED elements 220 to 240. The carrier pad 211 and the plurality of leads 212 are spaced apart from each other, and the carrier pad 211 includes an interconnection region for electrical connection with the plurality of leads and an extension region as a separate lead, which extends toward one corner of the lead frame 210 and is spaced apart from the first conductive hole 218 located at the corner. Second conductive vias 219 are located on the extended regions of the carrier pads to electrically connect the carrier pads with corresponding external pads; the extension regions of the carrier pads 211 are electrically connected to the corresponding outer pads 216 via second conductive vias 219. The diameter of the second conductive hole 219 is in a range including, but not limited to, 0.08 to 0.15 mm.

The plurality of leads 212 are spaced apart from each other for electrical connection with the LED elements 220-240 and extend to the outside of the encapsulant to provide electrical connection between the LED elements 220-240 and an external circuit. The lead frame 210 may define the shape of the carrier pad and the pins in a PCB fabrication process. Among them, the surfaces of the carrier pad and the plurality of pins in the lead frame 210 may further include an additional plating layer to improve conductivity, for example, a plating layer formed of a material selected from a metal such as nickel silver, nickel gold, nickel silver gold, etc., to the carrier pad 211 and the plurality of pins 212. The additional electroplated layer is electroplated to form a plated layer.

Further, referring to fig. 2a and 2b, the lead frame 210 may include a plurality of plated leads 260, the plurality of leads 212 are respectively connected to leads of adjacent LED packages via respective ones of the plurality of plated leads 260, or the extension region of the carrier pad 211 is connected to leads of adjacent LED packages via respective ones of the plurality of plated leads 260, or the outer pad 216 is respectively connected to an outer pad of adjacent LED packages via respective ones of the plurality of plated leads 260. The carrier pad 211 in the lead frame 210 is electrically connected to an external pad 216 on the back surface through the second conductive via 219 of the extension region, and the plating process is performed using the plating lead 260, thereby reducing the cost. The plating leads 260 may be wired on the front surface of the lead frame 210 or on the back surface of the lead frame 210. Referring to fig. 2a, a plurality of plated leads 260 are routed on the front side of the lead frame 210 to connect adjacent leads; referring to fig. 2b, a plurality of plated leads 260 are routed on the back side of the lead frame 210 to connect adjacent external pads. The thinner the lines of the plated leads 260, the better, the current flow is satisfied. The preferred wiring method is front diagonal wiring. The embodiment of the utility model provides a can utilize the electroplating lead to electroplate the metal layer surface of lead frame, it is specific, electroplate the reduce cost to a plurality of pins on lead frame surface, bear pad and a plurality of outside pad.

Further, the lead frame 210 may include internal pads 214 for receiving solder for electrical connection with the LED element.

The LED elements 220 to 240 are light emitting elements, the LED elements 220 to 240 respectively emit at least one of red light, green light and blue light, and the arrangement order of the

LED elements

220 and 240 is not limited. Therefore, the

LED elements

220 and 240 can emit light of the same color, two colors, or three colors at the same time, and thus the LED package structure can emit monochromatic light, dual-color light, or three-color light. For example, the LED element 220 is shown in fig. 1 as a red LED element in a vertical structure, and an anode electrode 221 and a cathode electrode (not shown) are formed on opposite surfaces, respectively. In the embodiment of the present invention, the anode electrode 221 of the LED element 220 is disposed on the upper surface of the LED element 220. The

LED elements

230 and 240 are a blue LED element and a green LED element, respectively, in a front-mount structure. For example, the anode electrode 231 and the cathode electrode 232 of the LED element 230 are respectively disposed on the upper surface of the LED element 230 and spaced apart from each other, and the anode electrode and the cathode electrode of the LED element 240 are respectively disposed on the upper surface of the LED element 240 and spaced apart from each other. However, the present invention is not limited thereto, and the red LED element, the green LED element, and the blue LED element may be vertical structures or upright structures, and may be selected according to design requirements.

The LED element 220 is fixed on the support pad 211 of the lead frame 210 by using a conductive adhesive (e.g., silver adhesive), so that the cathode electrode of the LED element 220 is electrically connected to the support pad 211. The cathode electrodes of the LED elements 220 are connected to the corresponding external pads 216 through the second conductive vias 219. With the bonding wires 215, cathode electrodes of the

LED elements

230 and 240 are connected to respective ones of the plurality of leads 212, and anode electrodes of the LED elements 220 to 240 are connected to a common one of the plurality of leads 212. The plurality of pins 212 connect the cathode electrodes of the

LED elements

230 and 240, and the anode electrodes of the LED elements 220 to 240 to the respective external pads 216 through the first conductive holes 218.

The encapsulant 250 allows light generated from the LED elements 220 to 240 to pass through, and the material of the encapsulant 250 is, for example, epoxy resin. The packaged LED package assembly has a thickness of about 0.5mm to 1.5mm, a length of about 0.5mm to 2mm, and a width of about 0.5mm to 2mm, but is not limited thereto.

The external pads 216 are used for electrical connection with an external circuit. For example, the external pads 216 of the LED package assembly may be fixed on a printed circuit board with solder and further connected to the display driving circuit via the printed circuit board.

The display driver circuit is operative to provide driving signals to the LED elements 220-240 of the LED package assembly 250 to control the brightness of the respective LED elements to produce desired color emission and desired brightness. After the LED packaging assembly is used as a pixel unit to form the LED display screen, the LED display screen can display image content under the control of the driving circuit.

In the LED package assembly of this embodiment, the carrier pad 211 is used to provide mechanical support for the LED elements 220 to 240 and to provide internal electrical connections for the LED element 220. The carrier pad 211 may include only an interconnection region for supporting the LED elements 220 to 240, and an extension region for providing the second conductive hole. In the LED package assembly 200 of this embodiment, the carrier pad 211 includes an extension region as a lead, which does not need to extend to the corner of the PCB substrate in the lead frame, and can be electrically connected to the corresponding external pad 216 through the corresponding second conductive via 219, thereby reducing the surface area of the carrier pad exposed on the bottom surface of the package material.

Further, the plurality of leads 212 respectively include a first portion for electrically connecting with the LED elements 220 to 240, a second portion connected with the external pad 216 through the first conductive via 218, and an intermediate portion extending between the first portion and the second portion. A first portion of the plurality of leads 212 is used to provide an interconnect region for electrical connection with bonding wires 215. In the example shown in fig. 1, the first portion of only one of the plurality of leads 212 is in the shape of a strip, and the first portions of the remaining two leads are in the shape of a triangle (i.e., one corner portion of the strip, i.e., a right triangle). The metal surface of the leadframe 210 exposed at the bottom surface of the package 250 of the encapsulation molding includes a first portion of the plurality of leads 212. However, since the shape of at least one of the leads is changed such that the first portion has a triangular shape, the pad is disposed at the tip of the triangle, thereby reducing the surface area of the lead 212 exposed on the surface of the PCB substrate 217.

The shape of the lead frame 210 and the connection manner between the lead frame 210 and the LED element significantly reduce the ratio of the metal surface of the lead frame 210 to the bottom surface of the encapsulant 250. When the LED element is not emitting light, the reflection of the ambient light by the metal surface of the lead frame 210 is also reduced, thereby improving the contrast of the LED display screen.

In the embodiment shown in fig. 1, the carrier pad 211 in the LED package assembly 200 is integrally formed, and the carrier pad 211 includes the interconnection region (first interconnection region) and the extension region connected to each other. The LED elements 220 to 240 are located on the interconnect region (first interconnect region). As an alternative embodiment, as shown in fig. 3, the interconnection region of the carrier pad 211 includes a first interconnection region and a second interconnection region spaced apart from each other, the first interconnection region being connected with the extension region; the LED element 220 is located on the first interconnect region;

LED elements

230 and 240 are located on the second interconnect region.

As another alternative embodiment, as shown in fig. 4, the interconnection region of the carrier pad 211 includes a first interconnection region, a second interconnection region and a third interconnection region spaced apart from each other, the first interconnection region being connected with the extension region; the LED elements 220 to 240 are located on the first, second and third interconnection regions, respectively.

In the embodiment shown in fig. 3 and 4, the LED element 220 is a vertical structure LED element, the second conductive via on the extension region is electrically connected to the external pad, and a plating layer may be formed on the first interconnection region by using a plating process. The second interconnection area and the third interconnection area can be formed with conductive plating layers by means of electroless plating.

In the embodiment shown in fig. 1, the LED elements 220 to 240 in the LED package assembly 200 are connected in a common anode manner. As an alternative embodiment, as shown in fig. 5, the LED elements 220 to 240 in the LED package assembly 200 are connected in a common cathode manner, for example, in fig. 5, the LED element 220 is shown as a vertically structured LED element, an anode electrode 221 and a cathode electrode (not shown) are respectively formed on opposite surfaces, the anode electrode 221 of the LED element 220 is disposed on an upper surface of the LED element 220, the cathode electrode of the LED element 220 is electrically connected to the carrying pad 211, the cathode electrode 232 of the LED element 230 and the cathode electrode 242 of the LED element 240 are connected to an extension region of the carrying pad 211 through a bonding wire 215, that is, the cathode electrodes of the LED elements are commonly connected to the extension region of the carrying pad 211 and electrically connected to the external pad 216 on the back side through the second conductive hole 219, so as to realize the common cathode connection of the LED elements 220 to 240.

In the embodiment shown in fig. 5, the carrier pad 211 in the LED package assembly 200 is integrally formed, and the carrier pad 211 includes the interconnection region (first interconnection region) and the extension region connected to each other. The LED elements 220 to 240 are located on the interconnect region (first interconnect region). As an alternative embodiment, as shown in fig. 6, the interconnection region of the carrier pad 211 includes a first interconnection region and a second interconnection region spaced apart from each other, the first interconnection region being connected with the extension region; the LED element 220 is located on the first interconnect region;

LED elements

230 and 240 are located on the second interconnect region.

As another alternative embodiment, as shown in fig. 7, the interconnection region of the carrier pad 211 includes a first interconnection region, a second interconnection region and a third interconnection region spaced apart from each other, the first interconnection region being connected with the extension region; the LED elements 220 to 240 are located on the first, second and third interconnection regions, respectively.

In the embodiment shown in fig. 6 and 7, the LED element 220 is a vertical structure LED element, the electrical connection is achieved through the second conductive via on the extension region and the external pad, and a plating layer may be formed on the first interconnection region using a plating process. The second interconnection area and the third interconnection area can be formed with conductive plating layers by means of electroless plating.

In step S10, the manufacturing of the lead frame is completed using a PCB fabrication process. For example, a plurality of first conductive holes from the first surface to the second surface of the PCB substrate are punched at the positions where a plurality of pins are located, a second conductive hole from the first surface to the second surface of the PCB substrate is punched at the extension region of the carrier pad, the shapes of the carrier pad and the pins are defined on the first surface of the PCB substrate by using a mask, a metal layer including the carrier pad and the plurality of pins is formed by an etching method, and a plating lead on the front surface or the back surface of the lead frame is also formed by etching; the plurality of pins are electrically connected with the external bonding pads on the second surface of the corresponding PCB substrate through the plurality of first conductive holes respectively, and the extension area of the bearing pad is used as an independent pin and is electrically connected with the external bonding pads on the second surface of the corresponding PCB substrate through the second conductive holes, so that the main structure of the lead frame is formed. As described above, the carrier pad of the lead frame employed in the LED package assembly according to the embodiment of the present invention is a separate element spaced apart from the pins.

In step S20, preferably, a lead frame surface treatment is performed. This step includes, for example, surface cleaning and formation of a plating layer. Plating layers made of a material selected from metals such as nickel, gold, silver, etc., such as nickel silver, nickel gold silver, etc., are formed on the surfaces of the carrier pads, the leads, and the external pads of the lead frame using the plating leads. The plating layer can improve conductivity, as well as provide wettability of the solder.

In a preferred embodiment, the interconnection region includes a first interconnection region and a second interconnection region spaced apart from each other, the first interconnection region is connected to the extension region, and the electrical connection is made to the external pad through the second conductive hole on the extension region, and the plating layer may be formed on the first interconnection region using a plating process. The second interconnection region forms a conductive coating by means of chemical plating

In a preferred embodiment, the interconnection region includes a first interconnection region, a second interconnection region and a third interconnection region spaced apart from each other, the first interconnection region is connected to the extension region, the electrical connection is achieved with the external pad through the second conductive hole on the extension region, and the plating layer may be formed on the first interconnection region using a plating process. And the second interconnection area and the third interconnection area are provided with conductive plating layers in an electroless plating mode.

In step S30, a plurality of LED elements are fixed to the pads of the lead frame using an adhesive. For a vertical structure LED element, the anode electrode and the cathode electrode are respectively located on the opposite surfaces of the LED element, so that a conductive adhesive (e.g. silver adhesive) can be used to adhere the vertical LED element to the carrier pad of the lead frame and to electrically connect the two.

In step S40, the electrodes of the LED element are connected to the plurality of leads using bonding wires. This step includes, for example, placing solder on the interconnect region of the lead, reflowing the solder by heating, and soldering the bonding wire to the interconnect region of the lead.

In step S50, the lead frame to which the LED element has been fixed is placed in a mold, and an encapsulant such as resin is injected to perform compression molding. The encapsulant may be a light transmissive material that allows light generated by the LED element to pass out. The encapsulant may also be formed with a light exit port, such as a frustum-shaped light exit port formed in the resin encapsulant, and the light exit sides of the three LED elements are exposed to the bottom of the light exit port.

In step S60, the LED packages formed in the above steps are separated into individual LED packages by dicing.

In the above embodiments, a method of directly forming a main structure of a lead frame using a PCB fabrication process is described. In an alternative embodiment, a stamping machining method is used to define the shapes of the carrier pad and the leads by using a die shape, and an additional support frame may be further included to temporarily support the carrier pad and the leads, and after the package is completed, a punch is used to cut off the connection between the lead frame and the support frame so that the LED package assembly forms an independent element, thereby forming the main body structure of the lead frame.

In accordance with the embodiments of the present invention as set forth above, these embodiments are not exhaustive and do not limit the invention to the precise embodiments described. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and its various embodiments with various modifications as are suited to the particular use contemplated. The protection scope of the present invention should be subject to the scope defined by the claims of the present invention.

Claims

1. An LED package assembly, comprising:

a lead frame having a carrier pad, a plurality of leads spaced apart from one another, and a plurality of external pads;

a first LED element, a second LED element and a third LED element which are fixed on the bearing pad of the lead frame and are electrically connected with the bearing pad and the pins; and

the packaging material is used for covering the lead frame and allowing light to penetrate out;

a plurality of first conductive holes positioned at corners of the lead frame to electrically connect the plurality of pins with the plurality of external pads, respectively;

wherein the carrier pad and the plurality of pins are spaced apart from each other, and the carrier pad includes an interconnection region electrically connected with the plurality of pins and an extension region as a pin;

the plurality of pins are electrically connected with the plurality of external bonding pads through first conductive holes at corresponding corners of the lead frame respectively;

and the second conductive hole is positioned on the extension area of the bearing pad so as to electrically connect the bearing pad with the corresponding external bonding pad.

2. The LED package assembly of claim 1, further comprising:

and a plurality of plating leads for forming a plating layer on the surface of the lead frame.

3. The LED package assembly of claim 2, wherein the plurality of leads and the surface of the carrier pad comprise a plated layer.

4. The LED package assembly of claim 2, wherein the plated leads are on the first surface of the leadframe and are connected to the extended regions of the carrier pad and/or the plurality of leads.

5. The LED package assembly of claim 2, wherein the surfaces of the plurality of outer pads comprise a plated layer.

6. The LED package assembly of claim 2, wherein the plated leads are on the second surface of the leadframe and are connected to the plurality of external pads.

7. The LED package assembly of claim 1, wherein the extended region extends toward a corner of the leadframe and is spaced apart from the first conductive via at the corner.

8. The LED package assembly of claim 1, wherein the first LED element, the second LED element, and the third LED element comprise an anode electrode and a cathode electrode, respectively, the first LED element is a vertical chip, and the second LED element and the third LED element are front mounted chips.

9. The LED package assembly of claim 1 or 8, wherein the carrier pad is connected to an anode electrode or a cathode electrode of one of the first LED element, the second LED element and the third LED element.

10. The LED package assembly of claim 1 or 8, wherein the anode and cathode electrodes of the first LED element are formed on opposing surfaces, the cathode electrode of the first LED element being electrically connected to the carrier pad.

11. The LED package assembly of claim 1 or 8, wherein anode electrodes of the first LED element, the second LED element and the third LED element are commonly connected to a common pin of the plurality of pins.

12. The LED package assembly of claim 1 or 8, wherein cathode electrodes of the first LED element, the second LED element and the third LED element are commonly connected to an extension of the carrier pad.

13. The LED package assembly of claim 1, wherein the first LED element, the second LED element and the third LED element emit at least one of red light, green light and blue light, respectively, and are arranged in an unlimited order.

14. The LED package assembly of claim 1, further comprising:

a plurality of bonding wires, the first LED element, the second LED element, the third LED element being connected to the plurality of leads via respective ones of the plurality of bonding wires, respectively.

15. The LED package assembly of claim 1, wherein the light exit side of each of the first, second and third LED elements is the side covered by the encapsulant.

16. The LED package assembly of claim 1, wherein the first LED element is secured to the carrier pad using a conductive adhesive.

17. The LED package assembly of claim 1, wherein the leadframe is a dual layer circuit board, the leadframe includes a PCB substrate, the carrier pad and the plurality of leads are located on a first surface of the PCB substrate, the plurality of external pads are located on a second surface of the PCB substrate, and the plurality of leads are electrically connected to the plurality of external pads through the first conductive vias between the first and second surfaces, respectively.

18. The LED package assembly of claim 1, wherein the interconnection region of the carrier pad comprises a first interconnection region, wherein the first LED element is located on the first interconnection region, the first interconnection region being connected to the extension region and to a corresponding external pad through a second conductive via.

19. The LED package assembly of claim 18, wherein the second LED element and the third LED element are both located on the first interconnect region.

20. The LED package assembly of claim 18, wherein the interconnection region of the carrier pad further comprises a second interconnection region spaced apart from the first interconnection region, the second LED element and the third LED element being located on the second interconnection region.

21. The LED package assembly of claim 18, wherein the interconnection region of the carrier pad further comprises a second interconnection region and a third interconnection region spaced apart from the first interconnection region;

the second and third LED elements are located on the second and third interconnect regions, respectively.

22. The LED package assembly of claim 20 or 21, wherein the first LED element is a vertical chip.

23. The LED package assembly of claim 1, wherein at least one of the plurality of leads is shaped as a missing corner diamond that leaves only one complete corner, the complete corner pointing toward the carrier pad, and the interconnect region is located at a top end of the complete corner.