Glue brushing device and glue brushing method for COB LED packaging

Abstract

The present invention proposes a glue brushing device and glue brushing method for COB LED packaging, comprising a base jig, a steel mesh and a glue brushing tool. The COB substrate to be glued is fixed by the base jig, and then the steel mesh is covered on the COB substrate. The glue brushing tool is used to print the prepared fluorescent glue through the through holes on the steel mesh onto the corresponding light-emitting area on the COB substrate. Not only is the glue amount control more accurate and the yield rate higher, but the entire glue brushing process is formed in one step, the process is simple, the production efficiency is improved, and multiple COB substrates can be printed at one time, which can achieve mass production. In addition, the fluorescent glue with high viscosity is selected, which is not easy to precipitate, thereby ensuring the consistency before and after production.

Description

Technical Field

[0001] The invention relates to the field of LEDs, in particular to a glue brushing device for COB LED packaging, and also to a glue brushing method using the glue brushing device. Background Art

[0002] The existing COB glue filling process usually includes the following steps: using a glue dispenser, first use the dam glue to surround the dam, then inject a certain amount of glue into the dam, and the glue spreads and flows level by gravity. The existing COB glue filling process has the following disadvantages:

[0003] (1) Using a dispensing machine to dispense glue is limited by the glue output accuracy of the dispensing machine, and the BIN consistency of the product is poor;

[0004] (2) The glue viscosity is low (it relies on gravity to level after injection), the phosphor is easy to precipitate, and the light parameters before and after a can of glue are different;

[0005] (3) The glue pouring process requires the following steps: dam enclosing → short baking → glue injection → long baking, which is a complicated process. Summary of the invention

[0006] In order to solve the above problems, the present invention proposes a glue applying device for COB LED packaging, and also proposes a method for applying glue using the glue applying device.

[0007] The main contents of the present invention include:

[0008] A glue brushing device for COB LED packaging, comprising a plurality of interconnected glue brushing units, wherein a single glue brushing unit comprises a steel mesh, a glue scraping tool and a base fixture, wherein the base fixture is provided with a COB fixing structure; the steel mesh covers the COB substrate, and a plurality of through holes are opened on the steel mesh, and the through holes correspond one to one with the COB light-emitting areas; a fluorescent glue loading position is provided on one side above the steel mesh; the glue scraping tool is arranged above the steel mesh, and reciprocates above the steel mesh.

[0009] Preferably, the base fixture includes a fixture body, the COB fixing structure includes a COB fixing groove, the COB fixing groove is opened on the fixture body, and a plurality of negative pressure suction cups are arranged at the bottom of the COB fixing groove.

[0010] Preferably, finger grooves are provided at both ends of the COB fixing groove, and the finger grooves are communicated with both end edges of the COB fixing groove.

[0011] Preferably, the steel mesh includes a steel mesh body, an organic coating is coated on the steel mesh body, the thickness of the organic coating is between 0.15mm and 0.3mm, the hardness of the organic coating is HV800, and the roughness is Ra3.2~6.4; the through hole passes through the organic coating and the steel mesh body.

[0012] Preferably, the inner wall of the through hole is coated with the organic coating; and the material of the steel mesh body is metal steel.

[0013] Preferably, the scraper tool comprises a tool body and a scraper, the scraper is arranged obliquely below the tool body, and the angle between the scraper and its forward direction is 55°.

[0014] Preferably, the scraper surface is coated with an organic coating, and the scraper is made of metal steel.

[0015] Preferably, the distance between the lower end of the scraper and the steel mesh is between 0.08 mm and 0.12 mm.

[0016] Preferably, the plurality of glue-brushing units are arranged in an array or the plurality of base fixtures are integrally formed.

[0017] The present invention also proposes a glue application method using the glue application device for COB LED packaging, comprising the following steps:

[0018] Step 1: prepare fluorescent glue so that the viscosity of the fluorescent glue is 10000-14000 mPa.s / 25°C;

[0019] Step 2: Stirring and degassing: put the prepared fluorescent glue into a vacuum degassing mixer. The speed of the vacuum degassing mixer is set in stages as follows: 300r / min 30s, 600r / min 30s, 900r / min 20s, 1200r / min 10s, and the vacuum degree is set to -90kpa;

[0020] Step 3: using plasma thermal spraying technology to coat the organic coating on the steel mesh and the brushing tool, wherein the thickness of the organic coating is 0.15-0.3 mm, the hardness is HV800, the roughness is Ra3.2-6.4, and the temperature resistance range is 0-450° C.;

[0021] Step 4: Placement: Install the COB substrate on the COB fixing structure of the base fixture, and cover the steel mesh on the COB substrate, and then load the fluorescent glue that has been stirred and degassed in step 2 to the fluorescent glue loading position;

[0022] Step 5: Printing: Move the glue brushing tool at a speed of 50 mm / s, and keep the angle between the glue brushing tool and the steel mesh at 55°, so as to print the fluorescent glue at the upper material position of the fluorescent glue through the through holes on the steel mesh onto the light-emitting area of ​​the COB substrate;

[0023] Step 6: Curing: Take out the glue-coated COB substrate, put it into the LED photoelectric oven, set the baking temperature to 100°, bake for 1 hour, then set the baking temperature to 150°, bake for 3 hours, and finally set the baking temperature to 170°, bake for 3 hours to cure the COB substrate.

[0024] The beneficial effects of the present invention are as follows: the present invention proposes a glue brushing device for COB LED packaging, wherein the COB substrate to be glued is fixed by a base fixture, and then a steel mesh is covered on the COB substrate, and a glue brushing tool is used to print the prepared fluorescent glue through the through holes on the steel mesh onto the corresponding light-emitting area on the COB substrate. Not only is the glue amount control more precise and the yield rate higher, but the entire glue brushing process is formed in one step, the process is simple, the production efficiency is improved, and multiple COB substrates can be printed at one time, which can realize mass production; in addition, the use of high-viscosity fluorescent glue is not easy to precipitate, thereby ensuring consistency before and after production. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the steel mesh of the present invention;

[0026] Figure 2 It is a structural schematic diagram of the base fixture of the present invention. DETAILED DESCRIPTION

[0027] The technical solution protected by the present invention is described in detail below with reference to the accompanying drawings.

[0028] Please refer to Figure 1 and Figure 2 The present invention proposes a glue brushing device for COB LED packaging, which eliminates the dam used in the existing glue dispensing process, simplifies the process of coating fluorescent glue, avoids problems such as voids caused by glue pouring and inconsistent glue thickness, improves the yield rate, and improves production efficiency.

[0029] The glue brushing device of the present invention includes a base fixture 9 for fixing the COB substrate, the COB substrate to be brushed with glue is arranged on the base fixture 9, and then the COB substrate is covered with a steel mesh 5, a plurality of through holes 6 are opened on the steel mesh 5, and the through holes 6 correspond to the luminous area on the COB substrate, and the through holes 6 can be any shape that is the same as the luminous area on the COB substrate, such as a circle or a square; a fluorescent glue loading position 8 is arranged on one side of the steel mesh 5, and the fluorescent glue to be printed is placed at the fluorescent glue loading position 8, and a glue scraping tool 7 for scraping glue is arranged on the outside of the fluorescent glue loading position 8, and above the steel mesh 5, the glue scraping tool 7 can move back and forth on the steel mesh 5, so as to apply the fluorescent glue through the through holes 6 to the luminous area of ​​the COB substrate. The entire printing process is formed in one step, and there is no need to first build a dam, which simplifies the processing flow, and the glue amount is more accurately controlled, the BIN is more concentrated, and the yield rate is improved.

[0030] In one embodiment, the viscosity of the fluorescent glue to be coated is limited to 1000-14000 mPa.s / 25°C to avoid the problem of high fluidity and difficulty in molding due to too low viscosity, and difficulty in coating due to too high viscosity.

[0031] In one embodiment, the base fixture 9 includes a fixture body, a COB fixing groove 90 is provided on the fixture body, and a finger groove 11 is also provided on the fixture body. The finger groove 11 is located at both ends of the COB fixing groove. The COB substrate is placed in the COB fixing groove 90. The finger groove 11 is connected to the COB fixing groove to facilitate the placement of the COB substrate. In other embodiments, a plurality of negative pressure suction cups 10 are provided at the bottom of the COB fixing groove 90 to further fix the COB substrate when the steel mesh 5 is picked up to prevent it from being taken away.

[0032] In one of the embodiments, the steel mesh 5 includes a steel mesh body, and the steel mesh body is coated with an organic coating. The material of the steel mesh body is metal steel. The organic coating adopts plasma thermal spraying technology, uses nickel-based alloy dispersion combined with polymer anti-sticking material, and uses the "bionic lotus leaf effect", so that the organic coating has extremely low adhesive peeling force and excellent wear resistance. The hardness of the organic coating is HV800, the roughness is Ra3.2~6.4, and the temperature resistance range is: within 0-450℃. In one of the embodiments, the thickness of the organic coating is 0.15~0.3MM, which is used to avoid glue adhesion residue and better ensure the consistency of glue amount of each product; further, the inner wall of the through hole 6 is also coated with the organic coating.

[0033] In one of the embodiments, the scraper 7 includes a tool body 71 and a scraper 70, and the scraper 70 is arranged below the tool body 71. The tool body 71 drives the scraper 70 to move back and forth, and the angle between the scraper 70 and its forward direction is 55°. If the angle is too small, the fluorescent glue will be pushed away prematurely, resulting in a lack of glue at the contact point between the scraper and the steel mesh; if the angle is too large, the fluorescent glue cannot rely on the downward pressure of the scraper, and only relying on gravity will result in incomplete molding; because the running speed of the scraper will also affect the filling effect of the fluorescent glue, in one of the embodiments, the moving speed of the scraper is set to 50mm / s to ensure the quality of printing.

[0034] More specifically, the surface of the scraper 70 is coated with an organic coating, and the scraper is made of metal steel.

[0035] In one embodiment, in order to ensure the quality of printing, the distance between the lower end of the scraper 70 and the upper surface of the steel mesh 5 is specifically between 0.08 mm and 0.12 mm, and preferably, the distance between the two is 0.1 mm.

[0036] In one embodiment, printing can be completed on one COB substrate at a time. In other embodiments, multiple COB substrates can be arranged in a certain order and printed at the same time, that is, multiple base fixtures 9 are arranged in sequence end to end, or multiple base fixtures 9 are arranged in an array manner, such as a four-connected plate manner consisting of a 2*2 matrix. In other embodiments, multiple base fixtures 9 can also be integrally formed into a whole, and a number of COB fixing grooves 90 are sequentially opened on the entire base fixture 9; accordingly, the steel mesh 5 and the scraper tool 7 can also be one or more.

[0037] The method for applying glue using the glue applying device of the present invention comprises the following specific steps:

[0038] Step 1: prepare fluorescent glue so that the viscosity of the fluorescent glue is 10000-14000 mPa.s / 25°C;

[0039] Step 2: Stirring and degassing: put the prepared fluorescent glue into a vacuum degassing mixer. The speed of the vacuum degassing mixer is set in stages as follows: 300r / min 30s, 600r / min 30s, 900r / min 20s, 1200r / min 10s, and the vacuum degree is set to -90kpa;

[0040] Step 3: using plasma thermal spraying technology to coat the organic coating on the steel mesh and the brushing tool, wherein the thickness of the organic coating is 0.15-0.3 mm, the hardness is HV800, the roughness is Ra3.2-6.4, and the temperature resistance range is 0-450° C.;

[0041] Step 4: Placement: Install the COB substrate on the COB fixing structure of the base fixture, and cover the steel mesh on the COB substrate, and then load the fluorescent glue that has been stirred and degassed in step 2 to the fluorescent glue loading position;

[0042] Step 5: Printing: Move the glue brushing tool at a speed of 50 mm / s, and keep the angle between the glue brushing tool and the steel mesh at 55°, so as to print the fluorescent glue at the upper material position of the fluorescent glue through the through holes on the steel mesh onto the light-emitting area of ​​the COB substrate;

[0043] Step 6: Curing: Take out the glue-coated COB substrate, put it into the LED photoelectric oven, set the baking temperature to 100°, bake for 1 hour, then set the baking temperature to 150°, bake for 3 hours, and finally set the baking temperature to 170°, bake for 3 hours to cure the COB substrate.

[0044] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A glue brushing device for COB LED packaging, characterized in that: It comprises a plurality of glue brushing units connected to each other, wherein a single glue brushing unit comprises a steel mesh, a glue scraping tool and a base fixture, wherein a COB fixing structure is arranged on the base fixture; the steel mesh covers the COB substrate, and a plurality of through holes are opened on the steel mesh, wherein the through holes correspond to the COB light-emitting areas one by one; a fluorescent glue loading position is arranged on one side above the steel mesh; the glue scraping tool is arranged above the steel mesh, and reciprocates above the steel mesh; The viscosity of the fluorescent glue is 10000~14000mPa.s / 25℃; The steel mesh comprises a steel mesh body, an organic coating is coated on the steel mesh body, the thickness of the organic coating is between 0.15 mm and 0.3 mm, the organic coating is a nickel-based alloy dispersion combined with a polymer anti-sticking material; the hardness of the organic coating is HV800, and the roughness is Ra3.2-6.4; the through hole penetrates the organic coating and the steel mesh body; The scraper tool comprises a tool body and a scraper, the scraper is tiltedly arranged below the tool body, and the angle between the scraper and its forward direction is 55°; The distance between the lower end of the scraper and the steel mesh is between 0.08 mm and 0.12 mm.

2. The glue brushing device for COB LED packaging according to claim 1, characterized in that: The base fixture comprises a fixture body, the COB fixing structure comprises a COB fixing groove, the COB fixing groove is arranged on the fixture body, and a plurality of negative pressure suction cups are arranged at the bottom of the COB fixing groove.

3. The glue brushing device for COB LED packaging according to claim 2, characterized in that: Finger grooves are provided at both ends of the COB fixing groove, and the finger grooves are communicated with the edges at both ends of the COB fixing groove.

4. The glue brushing device for COB LED packaging according to claim 1, characterized in that: The inner wall of the through hole is coated with the organic coating; the material of the steel mesh body is metal steel.

5. The glue brushing device for COB LED packaging according to claim 1, characterized in that: The scraper surface is coated with an organic coating, and the scraper is made of metal steel.

6. A glue brushing device for COB LED packaging according to any one of claims 1 to 5, characterized in that: The plurality of glue applying units are arranged in an array or the plurality of base fixtures are integrally formed.

7. A method for applying glue using a glue applying device for COB LED packaging as claimed in any one of claims 1 to 6, characterized in that: The steps include: Step 1: prepare fluorescent glue so that the viscosity of the fluorescent glue is 10000-14000 mPa.s / 25°C; Step 2: Stirring and degassing: put the prepared fluorescent glue into a vacuum degassing mixer. The speed of the vacuum degassing mixer is set in stages as follows: 300r / min 30s, 600r / min 30s, 900r / min 20s, 1200r / min 10s, and the vacuum degree is set to -90kpa; Step 3: using plasma thermal spraying technology to coat the organic coating on the steel mesh and the brushing tool, wherein the thickness of the organic coating is 0.15-0.3 mm, the hardness is HV800, the roughness is Ra3.2-6.4, and the temperature resistance range is 0-450°C; Step 4: Placement: Install the COB substrate on the COB fixing structure of the base fixture, and cover the steel mesh on the COB substrate, and then load the fluorescent glue that has been stirred and degassed in step 2 to the fluorescent glue loading position; Step 5: Printing: Move the glue brushing tool at a speed of 50 mm / s, and keep the angle between the glue brushing tool and the steel mesh at 55°, so as to print the fluorescent glue at the upper material position of the fluorescent glue through the through holes on the steel mesh onto the light-emitting area of ​​the COB substrate; Step 6: Curing: Take out the glue-coated COB substrate, put it into the LED photoelectric oven, set the baking temperature to 100°, bake for 1 hour, then set the baking temperature to 150°, bake for 3 hours, and finally set the baking temperature to 170°, bake for 3 hours to cure the COB substrate.

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