CN107464803A - It is a kind of based on wafer-level package can be from the LED filament preparation method of color-temperature regulating - Google Patents

Abstract

The invention discloses a method for preparing LED filaments with self-adjustable temperature based on chip-level packaging, which includes: preparing fluorescent adhesive films, preparing chip-level packaging flip-chips with different color temperatures, etching conductive lines on a substrate, and installing chips. The present invention provides a method for preparing LED filaments with self-adjustable temperature based on chip-level packaging. This method can meet the requirements of different luminous flux, color temperature, display index and light color, and meet the requirements of the actual living environment for light emission. By adjusting the magnitude of the line current where chips with different color temperatures are located, the desired lighting effect can be cleverly coupled. At the same time, it also increases the flexibility and scope of application of the LED filament, and is also suitable for large-scale industrial production.

Description

A kind of LED filament preparation method based on chip-scale packaging with self-adjustable temperature

technical field

The invention belongs to the lighting technology of LED lamps, and in particular relates to a method for preparing LED filaments with self-adjustable temperature based on chip-level packaging.

Background technique

Light Emitting Diode (Light Emitting Diode) light source, as a new type of green lighting source, has been widely used around the world for its characteristics of no pollution, long life, low loss, pure light color, and shock resistance. Chip-scale packaged LEDs have attracted wide attention due to their small package size, good heat dissipation performance, uniform light emission, and long life, and have become the industry's new favorite in recent years due to their high flexibility.

At present, large LED companies in Taiwan, Japan, South Korea, Europe and the United States have released similar chip-scale package LED products. Combining the products of various companies, the common feature is that based on the basis of flip chip, the packaging volume is smaller, and the optical and thermal performance is better. At the same time, because the steps of lead frame and wire bonding are omitted, the subsequent process is more convenient. At present, the production of CSP (ChipScale Package) LEDs in China is too much but not refined. They only achieve small-volume packaging. While the cost increases, its performance cannot meet expectations. The fundamental reason is that domestic manufacturers have not formed a scientific understanding of CSP. , while breaking through the CSP production technology, we made full use of the packaging advantages of CSP, applied CSP to LED filaments for the first time, and prepared LED filaments with self-adjustable temperature.

In recent years, LED filaments have become increasingly popular, and are sought after by people because of their own retro feelings. Some people have tried to prepare LED filaments: Huizhou Huarui Light Source Technology Co., Ltd., Ma Wenbo of Huarui Optoelectronics (Huizhou) Co., Ltd., etc. A LED filament ("LED filament", patent publication number: 105161597A) has been developed. This patent only protects the structure of a LED filament, but does not protect its performance and method. Jiang Tao of Jiaxing Shanpu Lighting Appliance Co., Ltd. developed a LED filament ("LED filament", patent publication number: 106838660A), which also improves the structure and optimizes the packaging material, and cannot achieve chip-level packaging flip-chip. Luminescence stability. Zhangzhou Lidaxin Optoelectronics Technology Co., Ltd. Zeng Maojin and others have developed an LED filament lamp, (LED filament lamp, patent publication number: 105485534A), but it is still only optimizing the structure for heat dissipation, and can only achieve a single luminous effect, and the luminescence is not flexible enough. , the applicable effect is not good. Not suitable for mass production. The current published literature and patents are all about the simple manufacturing process of LED filaments. The optimized structure and materials have not explained the performance, and there are no examples of multi-color temperature chips working together to emit light. We make additional improvements to the above problems and prepare chip-based Level packaging flip-chip LED filament with self-adjustable color temperature.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for preparing LED filaments with self-adjustable temperature based on chip-level packaging. According to the requirement of lighting, the user can ingeniously couple the required lighting effect by adjusting the magnitude of the line current where the chips with different color temperatures are located. At the same time, it also increases the flexibility and scope of application of the LED filament, and is also suitable for large-scale industrial production.

In order to solve the above problems, the technical solution of the present invention is:

A method for preparing an LED filament with self-adjustable temperature based on chip-scale packaging, comprising the steps of:

S1: Prepare fluorescent film;

Preferably, mix silica gel A, B glue with fluorescent powder, and make a fluorescent adhesive film by spin coating or screen printing, with a thickness between 0.2 and 0.6 mm;

S2: Prepare chip-scale package flip-chips with different color temperatures;

Preferably, the flip-chip blue light chip is laminated in the prepared fluorescent adhesive film, and after the fluorescent adhesive film is cured, it is cut with a dicing machine, and the pads and dicing chips inside the pressing machine are cut. Controlling the thickness of the machine blade to obtain a chip with a specified top package thickness and a specified side package thickness, and with different top package thicknesses and side package thicknesses, the chip-scale package flip chip with different color temperatures can be obtained;

S3: Etching conductive lines on the substrate: etching two or more conductive lines on the strip-shaped substrate, and leaving a preset bonding position between the conductive lines;

S4: chip installation: the packaged chip-level package flip-chips are alternately installed on the long on the preset crystal-bonding position on the strip substrate.

In the step S3, the elongated substrate is a rigid substrate or a flexible substrate.

In an embodiment of the present invention, the hard substrate is made of glass.

In an embodiment of the present invention, the hard substrate is made of light-transmitting ceramics.

In an embodiment of the present invention, the material of the flexible substrate is a metal substrate with good heat dissipation performance.

In an embodiment of the present invention, the material of the flexible substrate is a non-metallic substrate with good heat dissipation performance.

In the step S3, the conductive lines are connected in parallel, which is characterized in that the conductive lines share a positive pole of the power supply, and each conductive line is individually output as a first negative pole and a second negative pole.

Compared with the prior art, the present invention has the following advantages and positive effects due to the adoption of the above technical scheme:

The invention creatively uses chip-level packaged flip-chip combinations of various color temperatures to make LED filaments. During use, users can skillfully couple required lighting effects by adjusting the magnitude of line currents where chips with different color temperatures are located.

The present invention uses a chip-level packaged flip-chip instead of an ordinary front-mounted or flip-chip, which has a series of advantages such as high excitation efficiency, stable physical and chemical properties, high uniformity, high thermal conductivity, and simple post-processing technology, and overcomes the need for fluorescent powder packaging. Poor stability, easy aging and other issues; the flip-chip structure LED chip bonding process is simple, good heat dissipation; the present invention uses multi-color temperature chip parallel combination and can be matched with front and back crystal bonding, which can achieve different luminous flux, color temperature, CRI and The light color requirements meet the requirements of the actual living environment for light emission; the packaging process of the chip-scale package is simple, and the manufacturing process of the LED filament is simple, which is suitable for large-scale industrial production.

Description of drawings

FIG. 1 is a schematic diagram of a chip-scale packaged flip-chip Blu-ray chip in the present invention.

Fig. 2 is a schematic diagram of the LED filament in the present invention.

1-Fluorescent film

2-Chip Scale Package Flip-Chip 2-1 Flip-Chip Blu-ray Chip

3- LED filament 3-1 Conductive circuit 3-2 Strip substrate

4- Positive power supply

5-1 The first negative pole 5-2 The second negative pole

detailed description

A method for preparing an LED filament with self-adjustable temperature based on chip-scale packaging proposed by the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Advantages and features of the present invention will be apparent from the following description and claims. It should be noted that the drawings are all in a very simplified form and use imprecise ratios, which are only used to facilitate and clearly assist the purpose of illustrating the embodiments of the present invention.

A method for preparing an LED filament with self-adjustable temperature based on chip-scale packaging, comprising the steps of:

S1: Prepare fluorescent adhesive film 1;

Preferably, mix silica gel A, B glue with fluorescent powder, and make a fluorescent adhesive film by spin coating or screen printing, with a thickness between 0.2 and 0.6 mm;

S2: preparing chip-scale package flip-chips 2 with different color temperatures;

Preferably, the flip-chip blue-ray chip 2-1 is pressed into the prepared fluorescent adhesive film 1, and after the fluorescent adhesive film 1 is cured, it is cut with a dicing machine, and the pads and scribes inside the pressing machine are cut. Chip machine blade thickness control, to obtain chips with specified top package thickness and specified side package thickness, with different top package thicknesses and side package thicknesses, chip-level package flip chips with different color temperatures can be obtained2;

The present invention uses a chip-level packaged flip-chip instead of an ordinary front-mounted or flip-chip, which has a series of advantages such as high excitation efficiency, stable physical and chemical properties, high uniformity, high thermal conductivity, and simple post-processing technology, and overcomes the need for fluorescent powder packaging. Poor stability, easy aging and other problems.

S3: Etching conductive lines 3-1 on the substrate: etching two or more conductive lines 3-1 on the elongated substrate 3-2, and leaving a preset bonding position between the conductive lines 3-1;

S4: Chip installation: The packaged chip-scale package flip-chips 2 are installed on the strip-shaped substrate alternately according to the method of connecting chip-scale package flip-chips 2 with the same color temperature in series and chip-scale package flip-chips 2 with different color temperatures in parallel. 3-2 on the preset crystal bonding position.

The invention creatively uses chip-level packaged flip-chip combinations of various color temperatures to make LED filaments. During use, users can skillfully couple required lighting effects by adjusting the magnitude of line currents where chips with different color temperatures are located.

The present invention adopts parallel combination of multi-color temperature chips and can be matched with front and back solid crystals, which can meet different luminous flux, color temperature, display index and light color requirements, and meet the requirements for light emission in the actual living environment; the packaging process of the chip-level packaging is simple, and LED The filament manufacturing process is simple and suitable for large-scale industrial production.

In step S3, the elongated substrate 3-2 is a rigid substrate or a flexible substrate.

In a specific embodiment, the hard substrate is made of glass.

In a specific embodiment, the hard substrate is made of light-transmitting ceramics.

In a specific embodiment, the material of the flexible substrate is a metal substrate with good heat dissipation performance.

In a specific embodiment, the material of the flexible substrate is a non-metallic substrate with good heat dissipation performance.

In step S3, the conductive lines 3-1 are connected in parallel, which is characterized in that the conductive lines 3-1 share a power supply positive pole 4, and each conductive line 3-1 is separately output as a first negative pole 5-1 and a second negative pole 5-2.

The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and equivalent technologies, they still fall within the protection scope of the present invention.

Claims (6)

1. a kind of LED filament preparation method based on chip-scale packaging can self-adjust temperature, it is characterized in that, comprises the steps: S1: Prepare fluorescent adhesive film (1); S2: Prepare chip-scale package flip-chips with different color temperatures (2); S3: Etching conductive lines (3-1) on the substrate: etching two or more conductive lines (3-1) on the elongated substrate (3-2), and ) to reserve a preset crystal bonding position; S4: chip installation: connect the packaged chip-scale package flip-chips (2) in series according to the chip-scale package flip-chips (2) of the same color temperature, and connect the chip-scale package flip-chips (2) of different color temperatures in parallel installed alternately on the preset crystal-bonding positions on the elongated substrate (3-2). 2. A chip-scale package-based LED filament preparation method with self-adjustable temperature as claimed in claim 1, characterized in that, in the step S1, silica gel is mixed with fluorescent powder, and spin coating or filament coating is used to The fluorescent adhesive film (1) is prepared by a screen printing method, and the thickness of the fluorescent adhesive film (1) is between 0.2 mm and 0.6 mm. 3. A kind of LED filament preparation method based on chip-scale packaging as claimed in claim 1, characterized in that, in the step S3, the strip-shaped substrate (3-2) is hard Substrates or flexible substrates. 4. A method for preparing LED filaments with self-adjustable temperature based on chip-scale packaging as claimed in claim 3, wherein the hard substrate is made of glass or light-transmitting ceramics. 5 . The method for preparing an LED filament with self-adjustable temperature based on chip scale packaging as claimed in claim 3 , wherein the flexible substrate is made of a metal or non-metal substrate with good heat dissipation performance. 5 . 6. A chip-scale package-based LED filament preparation method capable of self-adjusting temperature as claimed in claim 1, characterized in that, in the step S3, the conductive lines (3-1) are connected in parallel , which is characterized in that the conductive lines (3-1) share a positive power supply (4), and each conductive line (3-1) is independently output as a first negative pole (5-1) and a second negative pole (5- 2).