CN102130227B - Encapsulation process for white light LED with optical lens - Google Patents

Abstract

The invention relates to a packaging process of a white light LED with an optical lens, and relates to a fluorescent powder coating process and a packaging process thereof. It solves the problems of uneven coating of phosphor powder and luminescence attenuation due to heating of phosphor powder in the existing method. Coating process: process a cylindrical groove at the center of the bottom surface of the LED optical lens, mix the phosphor powder with the glue, drop it into the cylindrical groove and let it stand until the glue solidifies to form a phosphor coating. Packaging process: Process the ring-shaped adhesive groove on the edge of the reflective cup on the copper base; fix the light-emitting chip in the reflective cup on the copper base and connect it to the printed circuit on the copper base; insert it into the reflective cup on the copper base Excessive injection of silica gel; buckle and fix the LED optical lens coated with phosphor layer on the copper base. The invention is suitable for the process of producing white light LED.

Description

Packaging process of white light LED with optical lens

technical field

The invention relates to a fluorescent powder coating process and its packaging process.

Background technique

As a light source, LED has many advantages such as low energy consumption, less heat generation, and long service life. It has been more and more widely used in lighting and decorative lamps. Step into the market of high-efficiency lighting sources.

At present, there are three common processes for realizing white light LEDs: the blue chip is coated with YAG phosphor powder; multiple chips or multiple devices of RGB three primary colors emit light and mix colors into white light; and the ultraviolet light chip is coated with RGB phosphor powder.

At present, the first process is commonly used, that is, the blue chip is coated with YAG phosphor powder, and the blue light excites the yellow-green light emitted by the phosphor powder and the blue light to synthesize white light. Usually, the phosphor is mixed with the glue and then applied to the chip with a dispenser and heated and cured.

In the above-mentioned process, there are three key problems: First, during the operation, because the viscosity of the carrier gel is a dynamic parameter, the specific gravity of the phosphor is greater than that of the carrier gel, resulting in precipitation, and the accuracy of the dispenser, the process fluorescence It is difficult to control the uniformity of the powder coating amount, which leads to uneven white light color; second, it is difficult to achieve consistent thickness of the glue on a single chip. Since the glue dispensed by the dispenser is approximately spherical each time, after curing The phosphor coating must be thick in the middle and thin in the periphery, and the light chromaticity of the final packaged LED is inconsistent from the middle to the periphery, yellowish in the middle and blue in the periphery; the third is the luminous attenuation problem caused by the heating of the phosphor, due to the current The LED packaging process is to directly dispense the mixture of phosphor powder and silica gel onto the chip, and when the chip is working, it will emit a lot of heat, which will cause the temperature around the chip to rise rapidly. As a result, the luminous efficiency of the phosphor powder will decrease due to heat. The continuous decline will eventually directly affect the life of the LED.

Contents of the invention

The purpose of the present invention is to solve the problems of uneven coating of phosphor powder and luminescence attenuation due to heating of phosphor powder in the existing method, so as to provide a packaging process of white light LED with optical lens.

The packaging process of the white light LED of the optical lens, the optical lens is obtained by the following phosphor powder coating process, the phosphor powder coating process is: a cylindrical groove is processed at the center of the bottom surface of the LED optical lens, and the Phosphor powder and glue are evenly mixed and then dropped into the cylindrical groove and left to stand until the glue solidifies. The phosphor is integrated with the optical lens through the glue and formed in the cylindrical groove at the bottom of the LED optical lens Phosphor coating;

The packaging process of white light LED with optical lens is realized by the following steps:

Step 1. Centering on a reflective cup on the copper base, process an annular glue groove on the copper base;

Step 2: Fix the light-emitting chip at the center of the inner bottom surface of the reflective cup, and connect the two electrodes of the light-emitting chip to the conductive copper foil on the copper base, and the conductive copper foil is insulated from the copper base;

Step 3: Inject an excessive amount of silica gel into the reflective cup on the copper base, so that the reflective cup is filled with silica gel, and let the excess silica gel flow into the adhesive groove;

Step 4, buckle and fix the LED optical lens coated with the phosphor layer on the copper base, and set the light-emitting chip at the center of the phosphor layer of the LED optical lens to realize the packaging of white light LED;

The area of the phosphor layer of the LED optical lens is greater than the area of the reflective cup mouth on the copper base, and the outer diameter of the annular glue groove is greater than or equal to the diameter of the cylindrical groove on the LED optical lens and less than or equal to the diameter of the LED optical lens. The largest diameter of an optical lens.

In the second step, the light-emitting chip is fixed in the reflective cup on the copper base by silver glue.

Beneficial effects: the phosphor powder after the process treatment of the present invention is evenly distributed and has a strong thickness consistency, and the silica gel is used to isolate the phosphor layer from the light-emitting chip, so that the heat of the phosphor powder is reduced, thereby effectively reducing the problem of luminous attenuation. The invention can greatly improve the color consistency of the LED and the service life of the LED.

Description of drawings

Fig. 1 is a schematic structural view of an optical lens obtained by the process of the first embodiment of the present invention; Fig. 2 is a schematic structural view of a white light LED obtained by the process of the second embodiment of the present invention; Fig. 3 is a process of the second embodiment of the present invention Schematic diagram of the structure of the obtained white LED group.

Detailed ways

Embodiment 1. The phosphor powder coating process of LED optical lens is characterized in that: its process is: processing a cylindrical groove at the center position of the bottom surface of LED optical lens 1, after mixing phosphor powder and glue evenly Drop into the cylindrical groove and stand until the glue is solidified, the phosphor is integrated with the optical lens through the glue and forms a phosphor coating 2 in the cylindrical groove at the bottom of the LED optical lens 1 .

The amount of the fluorescent powder and the glue liquid mixture dropped is less than or equal to the capacity of the cylindrical groove.

The mass percentage of the fluorescent powder in the mixture of the fluorescent powder and the glue solution is 60%-80%, and the balance is the glue solution. The glue is silicone.

The structure of the optical lens obtained by using the process in this embodiment is shown in FIG. 1 .

Specific embodiment two, adopt the white light LED encapsulation process of the optical lens that specific embodiment one obtains, it is realized by the following steps:

Step 1. Centering on a reflective cup 5 on the copper base 4, process the annular glue groove 7 on the copper base 4;

Step 2: Fix the light-emitting chip 6 at the center of the inner bottom surface of the reflective cup 5, and connect the two electrodes of the light-emitting chip 6 to the conductive copper foil on the copper base 4 respectively, and the conductive copper foil is connected to the copper base 4 Insulation between;

Step 3, excessively injecting silica gel 3 into the reflective cup 5 on the copper base 4, so that the reflective cup 5 is filled with silica gel 3, and the excess silica gel 3 flows into the glue introduction groove 7;

Step 4: Fasten and fix the LED optical lens 1 coated with the phosphor layer 2 on the copper base 4, and set the light-emitting chip 6 at the center of the phosphor layer 2 of the LED optical lens 1 to realize white light LED package;

The area of the phosphor layer 2 of the LED optical lens 1 is larger than the area of the cup mouth of the reflective cup 5 on the copper base 4, and the outer diameter of the annular glue groove 7 is larger than or equal to the cylindrical groove on the LED optical lens 1 The diameter is less than or equal to the maximum diameter of the LED optical lens 1 .

In this embodiment, the annular glue introduction groove 7 is composed of two semi-annular glue introduction grooves, and a circuit wiring area is left between the two semi-annular glue introduction grooves.

In step 2, the light-emitting chip 6 is fixed in the reflective cup 5 on the copper base 4 through silver glue. Eutectic bonding, adhesion, welding, etc. may also be used.

In step 4, before the silica gel is solidified, the LED optical lens 1 coated with the phosphor layer 2 is buckled and fixed on the copper base 4, and the optical lens 1 and the uncured silica gel are connected without gaps through extrusion. The structure of the white light LED obtained by adopting the process in this embodiment is shown in FIG. 2 .

In this embodiment, by setting up a plurality of reflective cups 5 on the copper base 4, and then repeating the above-mentioned steps for each reflective cup 5, that is, excessive glue injection and fastening of the LED optical lens 1 coated with the phosphor layer 2, the An LED group is obtained, and electrodes of a plurality of LEDs are connected in series to form an LED group as shown in FIG. 3 .

Claims (2)

1. The encapsulation process of the white light LED of the optical lens, the optical lens is obtained by the following phosphor coating process, the phosphor coating process is: processing a cylinder at the center of the bottom surface of the LED optical lens (1) shaped groove, mix the fluorescent powder and glue evenly, drop it into the cylindrical groove and let it stand until the glue solidifies, the fluorescent powder is integrated with the optical lens through the glue and is placed on the LED optical lens (1) A phosphor coating (2) is formed in the cylindrical groove at the bottom; It is characterized in that the encapsulation process of the white light LED of the optical lens is realized by the following steps: Step 1, centering on a reflective cup (5) on the copper base (4), process an annular glue groove (7) on the copper base (4); Step 2: Fix the light-emitting chip (6) at the center of the inner bottom surface of the reflective cup (5), and connect the two electrodes of the light-emitting chip (6) to the conductive copper foil on the copper base (4) respectively, so that Insulation between the conductive copper foil and the copper base (4); Step 3: Inject an excessive amount of silica gel (3) into the reflective cup (5) on the copper base (4), so that the reflective cup (5) is filled with silica gel (3), and let the excess silica gel (3) flow into the adhesive groove (7); Step 4. Fasten and fix the LED optical lens (1) coated with the phosphor layer (2) on the copper base (4), and set the light-emitting chip (6) to the fluorescent light of the LED optical lens (1). The center of the powder layer (2) realizes the encapsulation of white light LEDs; The area of the fluorescent powder layer (2) of the LED optical lens (1) is greater than the area of the cup mouth of the reflective cup (5) on the copper base (4), and the outer diameter of the annular glue groove (7) is greater than or equal to The diameter of the cylindrical groove on the LED optical lens (1) is less than or equal to the maximum diameter of the LED optical lens (1). 2. The packaging process of the white light LED of the optical lens according to claim 1, characterized in that in step 2, the light-emitting chip (6) is fixed in the reflective cup (5) on the copper base (4) by silver glue.

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