WO2020010920A1

WO2020010920A1 - Bendable and cuttable flexible light strip and fabrication method therefor

Info

Publication number: WO2020010920A1
Application number: PCT/CN2019/087378
Authority: WO
Inventors: 任瑞奇
Original assignee: 深圳市宇辰星光电有限公司
Priority date: 2018-07-13
Filing date: 2019-05-17
Publication date: 2020-01-16
Also published as: CN208687433U

Abstract

The present invention relates to a bendable and cuttable flexible light strip and a fabrication method therefor, and the light strip comprises a coating layer that extends along the length direction of the light strip, several flexible circuit board units distributed along the length direction of the light strips, and several LED light-emitting chips; the LED light-emitting chips employ a flip-chip structural form to be fixed onto the flexible circuit board units; a surface of the flexible circuit board units and LED light-emitting chips is spray-coated with a florescent powder layer, and the flexible circuit board units and the LED light-emitting chips are packaged by using a packaging adhesive; and the surface of the flexible circuit board units and LED light-emitting chips that carries the packaging adhesive and that is coated with the florescent powder layer is a glare-free light-emitting surface. The described light strip is convenient to mount, has a compact structure, may be flexibly applied, is easy to fabricate, has low costs and is easily promoted.

Description

Bendable and cuttable flexible light strip and manufacturing method thereof

Technical field

The invention relates to the technical field of lamp strips, in particular to a flexible lamp strip that can be bent and cut and a manufacturing method thereof.

Background technique

Various lighting sources are used to outline buildings and bridges, as well as lighting projects such as park squares and advertising lighting. Therefore, the application of flexible light strips is becoming more and more widespread.

The light strip is a LED lamp that is welded to a copper wire or a strip-shaped flexible circuit board using a special processing technology, and then connected to a power source to emit light. It is named because it is shaped like a light strip when it emits light.

At present, soft light strips on the market are usually made by patching LED (light emitting diode) light sources onto flexible circuit boards. The thickness of the light strip is limited by the height of the LED (light emitting diode), and the existing COB (on-chip package) ) Most of the light sources are aluminum substrates, copper substrates, ceramic substrates, etc. Similar substrates are rigid materials, which cannot be bent and cut at will. There are certain limitations in use, and the cost is high and it is not easy to maintain.

technical problem

In view of this, it is necessary to provide a flexible and flexible flexible light strip with a simple manufacturing process and low cost and a manufacturing method thereof.

Technical solutions

A bendable and cuttable flexible light strip includes a covering layer extending along the length direction of the light strip, a plurality of flexible circuit board units arranged along the length direction of the light strip, and a plurality of LED light emitting chips. The LED light emitting chips are flip-chip mounted. The chip structure is fixed on the flexible circuit board unit. The surface of the flexible circuit board unit and the LED light-emitting chip is sprayed with a phosphor layer. The flexible circuit board unit and the LED light-emitting chip are encapsulated by packaging glue. The side of the flexible circuit board unit of the encapsulant and the LED light-emitting chip coated with the phosphor layer is a non-glare light-emitting surface.

In a preferred solution, a groove extending in the direction of the light strip is provided on the upper surface of the flexible circuit board, the LED light-emitting chip is disposed in the groove, and an edge of the groove is sealed with a dam glue.

More preferably, positive and negative electrode pads are provided on both sides of the upper surface of the flexible circuit board, the positive and negative electrode pads are provided at the connection of the flexible circuit board unit, and the upper surfaces of the positive and negative electrode pads are provided. With cutout.

In one optional solution of the present invention, a current-limiting resistor is provided on the flexible circuit board. In another optional solution, a constant-current chip is provided on the flexible circuit board. A current resistor is used to limit the current of the flexible circuit board unit and the LED light emitting chip and play a voltage dividing role; when a constant current chip is provided, a constant current chip is provided on the flexible circuit board, and the constant current chip Provide a constant current for the flexible circuit board unit and the LED light emitting chip.

Preferably, the positive and negative electrode pads are provided in the cladding layer, and the cladding layer is provided on the flexible circuit board unit and an outer layer of the LED light emitting chip and its encapsulant. An electrode pad is electrically connected to the flexible circuit board unit, and a conductive plating layer is provided on the surface of the positive and negative electrode pads, so that the positive and negative electrode pads can be connected to an external circuit.

Preferably, a plurality of flexible circuit board units arranged along the length of the light strip are connected through a cutable conductive contact end, which is a positive terminal and a negative electrode end of each flexible circuit board unit, and a plurality of the flexible circuit board units are arranged along the length of the light strip. The flexible circuit board units are directly connected by welding with the same polarity electrode or directly by welding with the opposite polarity electrode.

Further, the LED light emitting chip uses a high power and small volume LED light emitting chip, so that the width of the light strip is reduced to 1 mm to 2 mm.

Further, the LED light emitting chip is provided on the light emitting surface in a regular arrangement or an irregular arrangement, and the light emitting surface is provided on all or part of an upper surface of the flexible circuit board unit.

And, a method for manufacturing a bendable and cuttable flexible light strip for manufacturing the bendable and cuttable flexible light strip as described above, which includes the following steps:

Making a number of flexible circuit board units, and arranging a number of flexible circuit board units along the length of the light strip and electrically connecting them together;

Forming a plurality of LED light emitting chips on each flexible circuit board unit by using a flip-chip process;

Fluorescent powder glue is continuously applied along the length of the light strip, and the LED light-emitting chip is covered by the fluorescent powder glue to form a continuous fluorescent glue layer to make the flexible and flexible light strip.

Further, after the phosphor glue is coated, the flexible circuit board unit is covered with a transparent packaging material to form an illumination light source.

Further, after the flexible lamp band that can be bent and cut is manufactured, the lamp band is further wound and collected.

Further, before manufacturing a plurality of flexible circuit board units, a full version of the multiple flexible circuit boards is provided, and the multiple flexible circuit boards are connected side by side into one body. Each flexible circuit board is a number of flexible circuit board units arranged along the length direction. After flip-chip forming a chip and coating the phosphor powder, each flexible circuit board is cut and separated, and then wound and collected.

Beneficial effect

In the above-mentioned bendable and cuttable flexible light strip and the manufacturing method thereof, the LED light emitting chip is flip-chip mounted on the flexible circuit board unit, and is coated with phosphor powder, which causes the LED light emitting chip to emit light. The light is softer and does not generate glare. After being encapsulated by the encapsulant, several flexible circuit board units are arranged in sequence to form a flexible light strip. Under the action of the current limiting resistor or the constant current chip, The voltage distribution of the lamp strip is realized, and a stable working voltage and current are provided for each of the flexible circuit board units, so that the flexible lamp strip can be infinitely extended and arbitrarily cut. Convenient installation, compact structure, flexible application, easy manufacture, low cost and easy promotion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural diagram of a bendable and cuttable flexible lamp strip according to an embodiment of the present invention.

FIG. 2 is a schematic structural diagram of the entire covered light emitting surface of the flexible lamp strip that can be bent and cut according to the embodiment of the present invention.

FIG. 3 is a schematic structural diagram of a part of a flexible light strip that can be bent and cut and covered with a light emitting surface according to an embodiment of the present invention.

Embodiments of the invention

The present invention will be described in detail below with reference to specific embodiments and drawings.

Please refer to FIG. 1, FIG. 2, and FIG. 3, which shows a flexible and flexible light strip 100 including a covering layer (not shown) extending along the length of the light strip, and several light strips arranged along the length of the light strip. Flexible circuit board unit 10 and several LED light emitting chips 20, the LED light emitting chip 20 is fixed to the flexible circuit board unit 10 in a flip-chip structure, and the flexible circuit board unit 10 and the LED light emitting chip 20 A phosphor layer is spray-coated on the surface, and the flexible circuit board unit 10 and the LED light-emitting chip 20 are encapsulated by an encapsulant 30. The flexible circuit board unit 10 with the encapsulant and the LED light-emitting chip 20 are spray-coated with phosphor. One side of the layer is a non-glare light-emitting surface.

Further, a groove 11 extending along the direction of the light strip is provided on the upper surface of the flexible circuit board. The LED light-emitting chip 20 is provided in the groove 11, and an edge of the groove 11 is packaged with a dam glue 12. .

Further, the LED light emitting chip 20 is provided on the light emitting surface in a regular arrangement or an irregular arrangement manner, and the light emitting surface is provided on all or part of the upper surface of the flexible circuit board unit 10.

Specifically, the flexible circuit board unit 10 and the LED light-emitting chip 20 adopt a chip-on-chip packaging process. The LED light-emitting chip 20 is disposed in the groove 11 and is enclosed by a dam glue 12 so that Dispens uniformly without climbing, and then directly encapsulate the gel mixed with fluorescent powder. The light-emitting surface can cover the entire surface or part of the surface of the flexible circuit board unit 10 as required, so that the flexible light strips have different widths.

Preferably, the encapsulant 30 is made of high-toughness gel, which is tightly combined with the flexible circuit board unit 10 and the LED light emitting chip 20 to increase the toughness and strength of the flexible light strip.

Further, positive and negative electrode pads 40 are respectively provided on the upper and lower sides of the flexible circuit board unit 10, preferably on both sides of the groove 11, and the positive and negative electrode pads 40 are provided on the flexible circuit board unit 10. At the connection, a shear mark 50 is provided on the upper surface of the positive and negative electrode pads 40. A conductive plating layer is provided on the surface of the positive and negative electrode pads 40, and the conductive plating layer is preferably a gold plating layer, a copper layer, or a tin plating layer, etc., so that the positive and negative electrode pads 40 can be connected to external lines. The positive and negative electrode pads 40 are disposed in the cladding layer, and the positive and negative electrode pads 40 are electrically connected to the flexible circuit board unit 10.

Specifically, the cutting mark 50 is provided on the positive and negative electrode pads 40, and the flexible light strip is cut along the cutting mark 50. The positive and negative electrode pads 40 are cut at the same time, cut and The exposed positive and negative electrode pads 40 can be connected to a power source for supplying power to the flexible light strip.

A plurality of flexible circuit board units 10 arranged along the length of the light strip are connected through a cutable conductive contact end, which is a positive terminal and a negative terminal of each flexible circuit board unit 10, and a number of flexible lines arranged along the length of the light strip. The circuit board unit 10 is directly connected by welding with the same polarity electrode or directly by welding with the opposite electrode.

In an optional solution of the present invention, a current limiting resistor 60 is provided on the flexible circuit board, so as to limit the magnitude of the current. In another alternative, for example, in a LED light source requiring a constant current, a constant current chip 70 is provided on the flexible circuit board. Wherein, when the current limiting resistor 60 is provided, the current of the flexible circuit board unit 10 and the LED light-emitting chip 20 and the voltage dividing function are provided; when the current limiting resistor 60 is provided, when the constant current chip 70 is provided, the The flexible circuit board 10 is provided with a constant current chip 70 that provides a constant current and voltage for the flexible circuit board unit 10 and the LED light emitting chip 20.

Specifically, the current-limiting resistor 60 and the constant-current chip 70 provide an operating voltage and an operating current for the flexible circuit board, so that the flexible lamp strip can extend indefinitely.

Further, the covering layer is provided on the outer layers of the flexible circuit board unit 10 and the LED light emitting chip 20 and its encapsulant 30, and the covering layer protects and supports the entire flexible light strip. Role.

Further, the LED light-emitting chip 20 uses a high-power and small-volume LED light-emitting chip 20 to reduce the width of the flexible light strip to 1 mm to 2 mm. The thickness of the flexible light strip can also be made very thin, for example, about 1 mm.

Specifically, the use of on-chip chip packaging technology and flip-chip technology not only solves the heat dissipation problem of the LED light emitting chip 20, but also prevents the LED light emitting chip 20 from being exposed to the air, polluted and damaged, and can greatly Reduce the volume and weight of the flexible light strip. At the same time, with the development of chip technology, the size of the LED light emitting chip 20 is getting smaller and smaller, so that the width of the flexible light strip is also greatly reduced.

In another aspect of the embodiments of the present invention, a method for manufacturing the flexible and flexible lamp strip 100 described above is provided, which includes the following steps:

S10, making a plurality of flexible circuit board units, and aligning the plurality of flexible circuit board units along the length of the light strip and electrically connecting them together;

S20, forming a plurality of LED light emitting chips on each flexible circuit board unit by using a flip-chip process;

S30. Fluorescent powder glue is continuously applied along the length of the light strip, and the LED light-emitting chip is covered with the fluorescent powder glue to form a continuous fluorescent glue layer to form the flexible and flexible light strip.

In practical applications, after coating the phosphor glue, the flexible circuit board unit is covered with a transparent packaging material to form an illumination light source. Specifically, a long strip of arrangable lighting strips can also be formed by installing the strips in a pre-made package. The package is a flexible structure that can also be rolled or tiled or embedded on the surface of a display.

In addition, after the flexible lamp band that can be bent and cut is manufactured, the lamp band is further wound and collected. For example, the light strip is rolled up by a take-up disc with a winding groove, and the length can be several meters or tens of meters, or even longer. When a predetermined length of light strip is required, it can be cut as needed.

In a preferred embodiment, before manufacturing a plurality of flexible circuit board units, a full version of the multiple flexible circuit boards is provided, and the multiple flexible circuit boards are connected side by side into one body. Each flexible circuit board is a plurality of flexible circuit boards arranged along the length direction. After the flexible circuit board unit is flip-chip-formed and coated with phosphor powder, the flexible circuit boards are cut and separated from each other, and then wound and collected.

In the above-mentioned bendable and cuttable flexible light strip 100, the LED light emitting chip 20 is flip-chip mounted on the flexible circuit board unit 10, and is sprayed with phosphor powder, which causes the light emitted by the LED light emitting chip 20 to emit light. It is softer and does not generate glare. After being encapsulated by the encapsulant 30 as a whole, a number of the flexible circuit board units 10 are arranged in sequence to form a flexible light strip. The current limit resistor 60 or the constant current chip 70 Under the action, the voltage and current distribution of the lamp strip is realized, and a stable working voltage and current is provided for each of the flexible circuit board units 10, so that the flexible lamp strip can be infinitely extended and arbitrarily cut. The installation structure of the invention is simple, easy to implement, low in cost, and convenient for popularization.

It should be noted that the present invention is not limited to the above embodiments. According to the creative spirit of the present invention, those skilled in the art can also make other changes. These changes made according to the creative spirit of the present invention should be included in the present invention. Within the scope of the claimed invention.

Claims

A bendable and cuttable flexible light strip is characterized in that it includes a covering layer extending along the length direction of the light strip, a plurality of flexible circuit board units arranged along the length direction of the light strip, and a plurality of LED light emitting chips. The LED emits light. The chip is fixed on the flexible circuit board unit with a flip-chip structure. The surface of the flexible circuit board unit and the LED light emitting chip is sprayed with a phosphor layer, and the flexible circuit board unit and the LED light emitting chip are packaged by a package. The surface of the flexible circuit board unit with the packaging glue and the LED light-emitting chip coated with the phosphor layer is a non-glare light-emitting surface.
The flexible light strip that can be bent and cut according to claim 1, wherein a groove extending in the direction of the light strip is provided on an upper surface of the flexible circuit board, and the LED light emitting chip is provided in the groove Inside, the edge of the groove is sealed with dam glue.
The flexible lamp strip that can be bent and cut according to claim 1, wherein positive and negative electrode pads are provided on both sides of the upper surface of the flexible circuit board, and the positive and negative electrode pads are provided on the flexible circuit board. At the connection of the flexible circuit board unit, a shear mark is provided on the upper surface of the positive and negative electrode pads.
The flexible lamp strip that can be bent and cut according to claim 1, wherein positive and negative electrode pads are provided on both sides of the upper surface of the flexible circuit board, and the positive and negative electrode pads are provided on the flexible circuit board. At the connection of the flexible circuit board unit, a shear mark is provided on the upper surface of the positive and negative electrode pads.
The flexible lamp strip that can be bent and cut according to claim 1, wherein positive and negative electrode pads are provided on both sides of the upper surface of the flexible circuit board, and the positive and negative electrode pads are provided on the flexible circuit board. At the connection of the flexible circuit board unit, a shear mark is provided on the upper surface of the positive and negative electrode pads.
The flexible and flexible light strip according to claim 1, wherein a plurality of flexible circuit board units arranged along the length of the light strip are connected by a cutable conductive contact end, and the conductive contact ends are each flexible The positive terminal and the negative terminal of the circuit board unit, and a plurality of flexible circuit board units arranged along the length of the lamp strip are directly connected by welding with the same electrode or directly by welding with the opposite electrode.
The flexible and flexible light strip as claimed in claim 1, wherein the LED light-emitting chip uses a high-power and small-volume LED light-emitting chip to reduce the width of the light strip to 1 mm to 2 mm .
The flexible and flexible lamp strip according to claim 1, wherein the LED light emitting chips are arranged on the light emitting surface in a regular or irregular arrangement, and the light emitting surface is provided on the flexible surface. All or part of the upper surface of the circuit board unit.
A method for manufacturing a flexible and flexible light strip for manufacturing a flexible and flexible light strip according to any one of claims 1-8, comprising the following steps:

Making a number of flexible circuit board units, and arranging a number of flexible circuit board units along the length of the light strip and electrically connecting them together;

Forming a plurality of LED light emitting chips on each flexible circuit board unit by using a flip-chip process;

Fluorescent powder glue is continuously applied along the length of the light strip, and the LED light-emitting chip is covered by the fluorescent powder glue to form a continuous fluorescent glue layer to make the flexible and flexible light strip.
The method for manufacturing a flexible and flexible flexible lamp strip according to claim 9, wherein after the fluorescent glue is coated, the flexible circuit board unit is covered with a transparent packaging material to form an illumination light source.
The method for manufacturing a bendable and cuttable flexible lamp strip according to claim 9, wherein after the bendable and cuttable flexible lamp strip is made, the lamp strip is further rolled and collected.
The method for manufacturing a flexible and flexible flexible light strip according to claim 11, characterized in that, before manufacturing a plurality of flexible circuit board units, a full-scale multi-circuit flexible circuit board is provided, and the multi-channel flexible circuit boards are connected side by side to One, each flexible circuit board is a number of flexible circuit board units arranged along the length direction. After the chips are flipped and coated with phosphor glue, each flexible circuit board is cut and separated, and then wound and collected.