Substrate-free flexible filament, packaging structure and production process thereof

Abstract

The invention relates to a substrate-free flexible lamp filament, a packaging structure and a production process thereof. According to the technical scheme, the process is characterized by comprising the steps that a carrier is manufactured in advance; a tin sheet is placed on the carrier, a conductive metal sheet and a plurality of LED chips are adhered to the tin sheet through glue, and the glue is cured; connecting the conductive metal sheet and the plurality of LED chips into a path, coating glue on the tin sheet, and curing to obtain a first glue layer wrapping the tin sheet, the plurality of LED chips and part of the conductive metal sheet; performing reflow soldering on the carrier together with the first glue layer and the conductive metal sheet to melt the tin sheet and separate the tin sheet from the first glue layer, the plurality of LED chips and the conductive metal sheet; the back face of the LED chip is coated with glue to generate a back face glue layer, and the substrate-free flexible lamp filament is obtained after curing; according to the flexible filament packaging structure, a PI film and a copper layer are removed, and the solder paste can absorb and consume light emitted by the chip, so that the light emitting efficiency of an LED can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of lighting equipment, and more specifically, to a substrate-free flexible filament, a packaging structure, and a production process thereof. Background Art

[0002] Flexible LED filament light source has long service life, low power consumption, strong flexibility, and the filament has a certain degree of bending, which can be constructed into different shapes, which conforms to the European and American retro lighting style.

[0003] Traditional LED flexible filament packaging methods usually require the use of a substrate to fix and support the LED chip, which not only increases production costs, but also due to the transmittance of the substrate (polyimide), material properties, prefabricated circuits on the substrate, and solder paste, all of which will block, absorb, and affect the transmittance of light, thereby reducing the light output efficiency of the LED. At the same time, there are problems such as large color difference in double-sided luminescence and low heat conduction efficiency. Summary of the invention

[0004] In view of the deficiencies in the prior art, the object of the present invention is to provide a substrate-free flexible filament, a packaging structure, and a production process thereof to solve the above-mentioned technical problems.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions: A production process of a substrate-free flexible filament, comprising: S1, pre-fabricating a carrier;

[0006] S2, placing a tin sheet on the carrier, adhering a conductive metal sheet and a plurality of LED chips to the tin sheet by glue, and curing the glue;

[0007] S3, connecting the conductive metal sheet and the plurality of LED chips into a path, coating glue on the tin sheet, and curing to obtain a first glue layer that wraps the tin sheet, the plurality of LED chips, and a portion of the conductive metal sheet;

[0008] S4, reflow soldering the carrier together with the first glue layer and the conductive metal sheet, so that the tin sheet is melted and separated from the first glue layer, the plurality of LED chips, and the conductive metal sheet;

[0009] S5. Apply glue on the back side of the LED chip to generate a back side glue layer, and obtain a substrate-free flexible filament after curing.

[0010] Optionally, the carrier includes: an outer frame; a plurality of tin sheet support blocks are arranged on the inner side of the outer frame; a first limit block corresponding to the conductive metal sheet is arranged on the outer frame; a movable block is slidably arranged on the outer frame; a spring is arranged between the movable block and the outer wall of the outer frame; one end of the spring is fixed to the outer wall of the outer frame, and the other end is fixed to the movable block; a second limit block corresponding to the conductive metal sheet is arranged on the movable block.

[0011] Optionally, the step of adhering the conductive metal sheet and the plurality of LED chips to the tin sheet by glue comprises:

[0012] Adhere a plurality of LED chips to the tin sheet using die-bonding glue in a preset arrangement order;

[0013] The positive conductive metal sheet is sleeved on the first limiting block, and the negative conductive metal sheet is sleeved on the second limiting block. The ends of the positive conductive metal sheet and the negative conductive metal sheet are bonded to the tin sheet by glue.

[0014] Optionally, the conductive metal sheet and the plurality of LED chips are connected to form a path, glue is coated on the tin sheet, and a first glue layer is obtained by curing the tin sheet, the plurality of LED chips, and a portion of the conductive metal sheet, including:

[0015] Use conductive wires to connect the conductive metal sheet and several LED chips into a path;

[0016] Applying a first glue on the tin sheet to cover the electrode surface of the LED chip, the tin sheet, and the ends of the positive conductive metal sheet and the negative conductive metal sheet;

[0017] The first glue is baked and cured to obtain a first glue layer that wraps a plurality of LED chips, tin sheets, and ends of the positive conductive metal sheet and the negative conductive metal sheet.

[0018] Optionally, the conductive metal sheet and the plurality of LED chips are connected to form a path, glue is coated on the tin sheet, and a first glue layer is obtained by curing the tin sheet, the plurality of LED chips, and a portion of the conductive metal sheet, including:

[0019] Use conductive wires to connect the conductive metal sheet and several LED chips into a path;

[0020] Apply glue above each LED chip on the tin sheet, the glue covers the LED chips and the conductive wires, and after curing, a second glue layer covering the LED chips and the conductive wires is obtained;

[0021] The movable block on the outer frame is stretched to make the second glue flat, and glue is coated on the second glue layer by glue coating equipment. The glue covers the second glue layer, the tin sheet, and the ends of the positive conductive metal sheet and the negative conductive metal sheet. After curing, the first glue layer is obtained, which wraps the first glue layer, the tin sheet, and the ends of the positive conductive metal sheet and the negative conductive metal sheet.

[0022] Optionally, reflow soldering the carrier together with the first glue layer and the conductive metal sheet to melt the tin sheet and separate it from the first glue layer, the plurality of LED chips, and the conductive metal sheet includes:

[0023] The carrier is placed on a steel plate, and the steel plate is placed in a reflow soldering device to perform reflow soldering on the steel plate, wherein the reflow soldering temperature is set to 260° C. and the time is set to 60 seconds;

[0024] The tin sheet is melted in the reflow soldering equipment and separated from the first glue layer, several LED chips, and the conductive metal sheet. The melted solder paste is collected in a steel tray.

[0025] Optionally, after coating glue on the back of the LED chip to form a back glue layer and curing to obtain a substrate-free flexible filament, the method further includes:

[0026] The substrate-free flexible filament is cut to obtain a substrate-free flexible filament of a predetermined width.

[0027] The present application also provides a substrate-free flexible filament, which is manufactured using the production process for the substrate-free flexible filament as described above.

[0028] The present application also provides a packaging structure of a substrate-free flexible filament, including: a first glue layer, a back glue layer, a positive conductive metal sheet, a negative conductive metal sheet, a plurality of LED chips, and a plurality of conductive wires corresponding to the plurality of LED chips; the plurality of LED chips and the plurality of conductive wires are correspondingly connected and conducted to form an LED chipset with conductive wires at both ends; the positive conductive metal sheet and the negative conductive metal sheet are respectively connected to the two ends of the LED chipset; the first glue layer covers the LED chipset, and part of the positive conductive metal sheet and the negative conductive metal sheet; the back glue layer is arranged on the back of the first glue layer.

[0029] The present application also provides a packaging structure of a substrate-free flexible filament, including: a first glue layer, a second glue layer, a back glue layer, a positive conductive metal sheet, a negative conductive metal sheet, a plurality of LED chips, and a plurality of conductive wires corresponding to the plurality of LED chips; the plurality of LED chips and the plurality of conductive wires are correspondingly connected and conducted to form an LED chipset with conductive wires at both ends; the positive conductive metal sheet and the negative conductive metal sheet are respectively connected to the two ends of the LED chipset; the second glue layer covers the LED chipset; the first glue layer covers the LED chipset, and part of the positive conductive metal sheet and the negative conductive metal sheet; the back glue layer is arranged on the back of the first glue layer.

[0030] In summary, the present invention has the following beneficial effects:

[0031] The substrate-free packaging structure does not require a substrate to fix and support the LED chip, which not only effectively reduces production costs, but also avoids the effects of the substrate on light transmission, such as blocking, absorption, and transmittance, thereby improving the light output efficiency of the LED. And since there is no need for a PI film, there is no need to consider the risk of high-temperature yellowing and embrittlement of the PI film. The power and temperature conditions of the product can be improved, the rated brightness of the product can be greatly improved, and at the same time, better heat dissipation can be achieved, thereby increasing the service life of the product. By using a carrier to carry the tin sheet, fix the position of the tin sheet, fix the position of the pins, and stretch the glue film, the problem of displacement of the LED chip during the production and use process is effectively avoided, thereby ensuring product quality and operability. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a process flow chart of the production process of the present invention;

[0033] Figure 2 It is a schematic diagram of the LED filament structure of the present invention;

[0034] Figure 3 is a schematic diagram of a conductive metal sheet of the present invention;

[0035] Figure 4 It is a front view schematic diagram of the carrier board in the present invention;

[0036] Figure 5 is a schematic side cross-sectional view of a carrier board in the present invention;

[0037] Figure 6 It is a schematic diagram of the welding wire material on the front side of the carrier board in the present invention;

[0038] Figure 7 It is a schematic diagram of the front-point outer layer adhesive material in the present invention;

[0039] Figure 8 It is a schematic diagram of the material after reflow soldering and tin removal on the back side of the carrier board of the present invention;

[0040] Fig. 9 It is a schematic diagram of the material after the back glue is dispensed in the present invention;

[0041] Fig.10 It is a schematic diagram of the material after the carrier plate is removed in the present invention;

[0042] Fig.11 This is a schematic diagram of filament cutting and root division in the present invention;

[0043] Fig.12 is a cross-sectional schematic diagram of Embodiment 4 of the present invention;

[0044] Fig.13 It is a cross-sectional schematic diagram of embodiment 5 of the present invention.

[0045] In the figure: 1. chip; 2. conductive wire; 3. first glue layer; 4. conductive metal sheet; 5. back glue layer; 6. conductive metal sheet process edge; 7. conductive metal sheet end; 8. positive conductive metal sheet marking hole; 9. carrier; 91. outer frame; 92. tin sheet support block; 93. first limit block; 94. movable block; 95. spring; 96. second limit block; 10. tin sheet; 11. conductive metal sheet bonding glue; 12. solid crystal glue; 13. second glue layer. DETAILED DESCRIPTION

[0046] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings. Several embodiments of the present invention are shown in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0047] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0048] In the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, the first feature being "above", "above" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature. The terms "vertical", "horizontal", "left", "right", "above", "below" and similar expressions are for illustrative purposes only, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0049] The present invention is described in detail below in conjunction with the accompanying drawings and embodiments.

[0050] Embodiment 1

[0051] This embodiment provides a production process for a substrate-free flexible filament. Figure 1-13 As shown, including:

[0052] S1, pre-fabricate a carrier 9;

[0053] S2, placing a tin sheet 10 on the carrier 9, adhering the conductive metal sheet 4 and a plurality of LED chips 1 to the tin sheet 10 by glue, and curing the glue;

[0054] S3, connecting the conductive metal sheet 4 and the plurality of LED chips 1 into a path, coating the tin sheet 10 with glue, and curing to obtain a first glue layer 3 that wraps the tin sheet 10, the plurality of LED chips 1, and a portion of the conductive metal sheet 4;

[0055] S4, reflow soldering the carrier 9 together with the first glue layer 3 and the conductive metal sheet 4, so that the tin sheet 10 is melted and separated from the first glue layer 3, the plurality of LED chips 1, and the conductive metal sheet 4;

[0056] S5, coating glue on the back side of the LED chip 1 to form a back side glue layer 5, and obtaining a substrate-free flexible filament after curing.

[0057] Specifically, the pre-set carrier 9 has the functions of carrying the tin sheet 10, fixing the position of the tin sheet 10, fixing the pin position of the conductive metal sheet 4, and stretching the glue film. Subsequent solid crystal, wire bonding, and glue dispensing are all performed on the carrier 9. The tin sheet 10 is fixed to the corresponding position on the carrier, the LED chip 1 and the conductive metal sheet 4 are adhered to the tin sheet 10 with glue, and the glue is cured to fix the LED chip 1 and the conductive metal sheet 4 on the tin sheet 10; after the LED chip 1 and the conductive metal sheet 4 are connected into a path, glue is applied to the tin sheet 10, and cured to obtain a first glue layer 3 that can fix the LED chip 1, the tin sheet 10 and part of the conductive metal sheet 4; and the carrier 9 together with the LED chip 1, the tin sheet 10 on the carrier 9 is fixed. 0. The conductive metal sheet 4 and the first glue layer 3 are put into the reflow soldering equipment together, and the reflow soldering treatment is performed at a preset temperature. The tin sheet 10 melts in the reflow soldering equipment and falls off from the first glue layer 3. After the reflow soldering treatment, the first glue layer 3 only connects the conductive metal sheet 4 and the LED chip 1, and then the back glue is covered on one side of the bottom of the LED chip 1. After curing, a flexible filament with only the LED chip 1 and the conductive metal sheets 4 at both ends wrapped only by the first glue layer 3 and the back glue layer 5 can be obtained.

[0058] Since the flexible filament packaging method of this scheme does not require a substrate and adopts a positive chip 1, the light output efficiency of the LED is effectively improved; because a substrate-free packaging structure is adopted, the influence of the substrate on the propagation of light, such as blocking, absorption, and transmittance, is eliminated, and at the same time, the production cost can be effectively reduced, meeting the market demand for improved light efficiency of flexible filament products.

[0059] Optionally, the carrier 9 includes: an outer frame 91; a plurality of tin sheet support blocks 92 are arranged on the inner side of the outer frame 91; a first limit block 93 corresponding to the conductive metal sheet 4 is arranged on the outer frame 91; a movable block 94 is slidably arranged on the outer frame 91; a spring 95 is arranged between the movable block 94 and the outer wall of the outer frame 91; one end of the spring 95 is fixed to the outer wall of the outer frame 91, and the other end is fixed to the movable block 94; a second limit block 96 corresponding to the conductive metal sheet 4 is arranged on the movable block 94.

[0060] Specifically, the tin sheet 10 is placed on the tin sheet support block 92, and then the LED chip 1 is set on the tin sheet 10. The process end of the positive conductive metal sheet 4 is sleeved on the first limit block 93, and the positive conductive metal sheet 4 is partially overlapped on the tin sheet 10; the process end of the negative conductive metal sheet 4 is sleeved on the second limit block 96, and the negative conductive metal sheet 4 is partially overlapped on the tin sheet 10, and the subsequent crystal bonding, wire bonding, and glue dispensing processes can be carried out on the carrier 9.

[0061] Optionally, the step of adhering the conductive metal sheet 4 and the plurality of LED chips 1 to the tin sheet 10 by glue comprises:

[0062] Adhere a plurality of LED chips 1 to the tin sheet 10 using a bonding adhesive 12 in a preset arrangement order;

[0063] The positive conductive metal sheet 4 is sleeved on the first limiting block 93 , and the negative conductive metal sheet 4 is sleeved on the second limiting block 96 . The ends of the positive conductive metal sheet 4 and the negative conductive metal sheet 4 are bonded to the tin sheet 10 by glue.

[0064] A plurality of LED chips 1 are adhered to the tin sheet 10 with a crystal bonding glue 12 in a preset arrangement order using a crystal bonding device, thereby fixing the position of the LED chips 1. Subsequently, the ends of the positive conductive metal sheet 4 and the negative conductive metal sheet 4 are bonded to the tin sheet 10 with glue to fix the position of the positive conductive metal sheet 4 and the negative conductive metal sheet 4. An oven or a tunnel oven is then used to solidify the glue to form a whole. The temperature of the oven and the tunnel oven is set to 170°C, and the baking time is set to 2 hours.

[0065] Optionally, the conductive metal sheet 4 and the plurality of LED chips 1 are connected to form a path, glue is coated on the tin sheet 10, and a first glue layer 3 wrapping the tin sheet 10, the plurality of LED chips 1, and a portion of the conductive metal sheet 4 is obtained after curing, including:

[0066] Use conductive wire 2 to connect the conductive metal sheet 4 and a plurality of LED chips 1 into a path;

[0067] A first glue is applied on the tin sheet 10 to cover the electrode surface of the LED chip 1, the tin sheet 10, and the ends of the positive conductive metal sheet 4 and the negative conductive metal sheet 4;

[0068] The first glue is baked and cured to obtain a first glue layer 3 that wraps the plurality of LED chips 1 , the tin sheet 10 , and the ends of the positive electrode conductive metal sheet 4 and the negative electrode conductive metal sheet 4 .

[0069] Use wire bonding equipment to connect the conductive metal sheet 4 and several LED chips 1 into a path with conductive wires 2. The conductive wires 2 can be gold wires, alloy wires, silver wires, copper wires, etc. Use glue coating equipment, glue scraping equipment, etc. to coat the first glue on the electrode surface of the chip 1 at the position of the LED chip 1 on the tin sheet 10, covering the tin sheet 10, the LED chip 1, the conductive wires 2, and part of the conductive metal sheet 4, and bake to shape the glue. The first glue can be filled with phosphors of different proportions or phosphors with other particles to achieve different color temperature and brightness requirements.

[0070] Optionally, the carrier 9 together with the first glue layer 3 and the conductive metal sheet 4 is subjected to reflow soldering to melt the tin sheet 10 and separate it from the first glue layer 3, the plurality of LED chips 1, and the conductive metal sheet 4, including:

[0071] The carrier 9 is placed on a steel plate, and the steel plate is placed in a reflow soldering device to perform reflow soldering on the steel plate, with the reflow soldering temperature set to 260° C. and the time set to 60 seconds;

[0072] The tin sheet 10 is melted in the reflow soldering equipment and separated from the first glue layer 3, the LED chips 1, and the conductive metal sheet 4. The melted solder paste is stored in a steel tray.

[0073] By setting the reflow soldering temperature to a specified temperature, the tin sheet 10 is completely melted in the reflow soldering equipment and separated from the first glue layer 3 and the LED chip 1. The melted solder paste is stored in the steel tray for reuse. After the carrier 9 is taken out of the reflow soldering equipment, the first glue layer 3 with the tin sheet 10 removed is cleaned and placed in an oven for dehumidification. The oven temperature is set to 60°C and the time is set to 1 hour.

[0074] The spring 95 and screws on the carrier are used to move the movable block 94 outwards for a certain distance, so that the first glue layer 3 is stretched and leveled, and then glue is injected using glue coating equipment, spraying equipment, glue scraping equipment or glue injection equipment to cover the bottom side of the LED chip 1 with glue on the back of the chip 1, and then bake to form the glue. The glue on the back of the chip 1 is used in conjunction with the appearance of the first glue layer 3 on the electrode surface of the chip 1, and can be phosphor, a combination of phosphors mixed with other particles, etc.

[0075] Optionally, after coating glue on the back of the LED chip 1 to form the back glue layer 5 and curing to obtain the substrate-free flexible filament, the method further includes:

[0076] The substrate-free flexible filament is cut to obtain a substrate-free flexible filament of a predetermined width.

[0077] The process edge of the conductive metal sheet 4 is cut off by using a die-cutting device to form a single metal conductive pin, which is then cut into filaments of corresponding width according to the appearance requirements of the filament.

[0078] The flexible filament of the present application has no substrate, and a cut tin sheet 10 is used as an operating platform. The thickness of the tin sheet 10 is preferably 0.5-1.5 mm. The tin sheet 10 melts during the reflow process and is separated from the chip 1 and the glue layer. The LED chip 1 is preferably a non-back-plated front-mounted chip 1; the first glue and the back glue can be applied using simple coating methods such as printing and dispensing, and the appearance of the product can be arc-shaped or flat according to customer requirements. And the first glue layer 3 and the back glue layer 5 can be set in multiple layers. The first glue and the back glue are made of silicone resin or silica gel, mixed with a certain proportion of granular material, which can be only fluorescent powder, or a mixture of fluorescent powder and other particles. Other particles can be heat dissipation particles such as silicon dioxide and aluminum oxide, or PET flash powder, titanium dioxide, different colors of mineral powder and other particles that change the appearance color.

[0079] Embodiment 2

[0080] This embodiment provides a production process for a substrate-free flexible filament. Figure 1-13 As shown, it includes: S1, pre-fabricating a carrier 9;

[0081] S2, placing a tin sheet 10 on the carrier 9, adhering the conductive metal sheet 4 and a plurality of LED chips 1 to the tin sheet 10 by glue, and curing the glue;

[0082] S3, connecting the conductive metal sheet 4 and the plurality of LED chips 1 into a path, coating the tin sheet 10 with glue, and curing to obtain a first glue layer 3 that wraps the tin sheet 10, the plurality of LED chips 1, and a portion of the conductive metal sheet 4;

[0083] S4, reflow soldering the carrier 9 together with the first glue layer 3 and the conductive metal sheet 4, so that the tin sheet 10 is melted and separated from the first glue layer 3, the plurality of LED chips 1, and the conductive metal sheet 4;

[0084] S5, coating glue on the back side of the LED chip 1 to form a back side glue layer 5, and obtaining a substrate-free flexible filament after curing.

[0085] Optionally, the carrier 9 includes: an outer frame 91; a plurality of tin sheet support blocks 92 are arranged on the inner side of the outer frame 91; a first limit block 93 corresponding to the conductive metal sheet 4 is arranged on the outer frame 91; a movable block 94 is slidably arranged on the outer frame 91; a spring 95 is arranged between the movable block 94 and the outer wall of the outer frame 91; one end of the spring 95 is fixed to the outer wall of the outer frame 91, and the other end is fixed to the movable block 94; a second limit block 96 corresponding to the conductive metal sheet 4 is arranged on the movable block 94.

[0086] Optionally, the step of adhering the conductive metal sheet 4 and the plurality of LED chips 1 to the tin sheet 10 by glue comprises:

[0087] Adhere a plurality of LED chips 1 to the tin sheet 10 using a bonding adhesive 12 in a preset arrangement order;

[0088] The positive conductive metal sheet 4 is sleeved on the first limiting block 93 , and the negative conductive metal sheet 4 is sleeved on the second limiting block 96 . The ends of the positive conductive metal sheet 4 and the negative conductive metal sheet 4 are bonded to the tin sheet 10 by glue.

[0089] Optionally, the conductive metal sheet 4 and the plurality of LED chips 1 are connected to form a path, glue is coated on the tin sheet 10, and a first glue layer 3 wrapping the tin sheet 10, the plurality of LED chips 1, and a portion of the conductive metal sheet 4 is obtained after curing, including:

[0090] Use conductive wire 2 to connect the conductive metal sheet 4 and a plurality of LED chips 1 into a path;

[0091] Glue is applied on the top of each LED chip 1 on the tin sheet 10, and the glue covers the LED chips 1 and the conductive wires 2. After curing, a second glue layer 13 wrapping the LED chips 1 and the conductive wires 2 is obtained;

[0092] The movable block 94 on the stretch outer frame 91 is stretched to make the second glue flat, and glue is coated on the second glue layer 13 by the glue coating equipment. The glue covers the second glue layer 13, the tin sheet 10, and the ends of the positive conductive metal sheet 4 and the negative conductive metal sheet 4. After curing, the first glue layer 3 that wraps the first glue layer 3, the tin sheet 10, and the ends of the positive conductive metal sheet 4 and the negative conductive metal sheet 4 is obtained.

[0093] Use glue coating equipment to coat glue on each LED chip 1 on the tin sheet 10, so that the glue only covers the chip 1 and the conductive wire 2, and bake to shape the glue, so as to obtain a second glue layer 13 that wraps a plurality of LED chips 1 and the conductive wire 2. The second glue layer 13 on the electrode surface of the chip 1 can be filled with phosphors of different proportions or phosphors with other particles to achieve different color temperature and brightness requirements.

[0094] Then, the spring 95 and screws on the carrier are arranged to make the carrier movable block 94 a certain distance away, so that the glue film is stretched and flat, and then glue coating equipment, glue scraping equipment and other equipment are used to apply glue on the second glue layer 13 on the electrode surface of the chip 1, and the first glue layer 3 on the electrode surface of the chip 1 covers all the second glue layer 13 on the electrode surface of the chip 1, the tin sheet 10, and part of the conductive metal sheet 4, and the glue is baked to form the glue. The first glue layer 3 on the electrode surface of the chip 1 can be filled with phosphors of different proportions or phosphors with other particles to achieve different color temperature and brightness requirements.

[0095] Optionally, the carrier 9 together with the first glue layer 3 and the conductive metal sheet 4 is subjected to reflow soldering to melt the tin sheet 10 and separate it from the first glue layer 3, the plurality of LED chips 1, and the conductive metal sheet 4, including:

[0096] The carrier 9 is placed on a steel plate, and the steel plate is placed in a reflow soldering device to perform reflow soldering on the steel plate, with the reflow soldering temperature set to 260° C. and the time set to 60 seconds;

[0097] The tin sheet 10 is melted in the reflow soldering equipment and separated from the first glue layer 3, the LED chips 1, and the conductive metal sheet 4. The melted solder paste is stored in a steel tray.

[0098] Use glue coating equipment, spraying equipment, glue scraping equipment or glue injection equipment to cover the other side of LED chip 1 with glue on the back of chip 1, and then bake to form the glue. The glue on the back of chip 1 is used in conjunction with the appearance of the glue on the back of chip 1, and can be fluorescent powder, a combination of fluorescent powders mixed with other particles, ceramic powder, titanium dioxide powder, PET glitter and other colored particle glues.

[0099] Optionally, after coating glue on the back of the LED chip 1 to form the back glue layer 5 and curing to obtain the substrate-free flexible filament, the method further includes:

[0100] The substrate-free flexible filament is cut to obtain a substrate-free flexible filament of a predetermined width.

[0101] Embodiment 3

[0102] This embodiment provides a substrate-free flexible filament, which is manufactured using the production process for the substrate-free flexible filament described in the first or second embodiment.

[0103] The substrate-free flexible filament produced by the production process of Example 1 or Example 2 adopts a substrate-free packaging structure, and there is no need to use a substrate to fix and support the LED chip 1, which not only effectively reduces the production cost, but also avoids the influence of the substrate on the blocking, absorption, and transmittance of light propagation, thereby improving the light extraction efficiency of the LED. And because the PI film is not required, there is no need to consider the risk of high-temperature yellowing and embrittlement of the PI film, the product power and temperature conditions can be improved, the product rated brightness can be greatly improved, and at the same time, a better heat dissipation effect can be achieved, and the service life of the product can be improved. By using a carrier 9 to carry the tin sheet 10, fix the position of the tin sheet 10, fix the position of the pin, and stretch the glue film, the problem of displacement of the LED chip 1 during the production and use process is effectively avoided, thereby ensuring product quality and operability.

[0104] Embodiment 4

[0105] This embodiment provides a packaging structure of a flexible filament without a substrate based on the production process of the flexible filament without a substrate in Example 1. Fig.12 As shown, it includes: a first glue layer 3, a back glue layer 5, a positive conductive metal sheet 4, a negative conductive metal sheet 4, a plurality of LED chips 1, and a plurality of conductive wires 2 corresponding to the plurality of LED chips 1; the plurality of LED chips 1 and the plurality of conductive wires 2 are correspondingly connected and conducted to form a group of LED chips 1 with conductive wires 2 at both ends; the positive conductive metal sheet 4 and the negative conductive metal sheet 4 are respectively connected to the two ends of the LED chip group 1; the first glue layer 3 covers the LED chip group 1, and part of the positive conductive metal sheet 4 and the negative conductive metal sheet 4; the back glue layer 5 is arranged on the back of the first glue layer 3.

[0106] Embodiment 5

[0107] This embodiment provides a packaging structure of a flexible filament without a substrate based on the production process of the flexible filament without a substrate in the second embodiment. Fig.13 As shown, it includes: a first glue layer 3, a second glue layer 13, a back glue layer 5, a positive conductive metal sheet 4, a negative conductive metal sheet 4, a number of LED chips 1, and a number of conductive wires 2 corresponding to the number of LED chips 1; the number of LED chips 1 and the number of conductive wires 2 are correspondingly connected and conducted to form a group of LED chips 1 with conductive wires 2 at both ends; the positive conductive metal sheet 4 and the negative conductive metal sheet 4 are respectively connected to the two ends of the LED chip group 1; the second glue layer 13 covers the LED chip group 1; the first glue layer covers the LED chip group 1, and part of the positive conductive metal sheet 4 and the negative conductive metal sheet 4; the back glue layer 5 is arranged on the back of the first glue layer 3.

[0108] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A production process for a substrate-free flexible filament, characterized in that: include: S1. Prepare a carrier in advance; S2, placing a tin sheet on the carrier, adhering a conductive metal sheet and a plurality of LED chips to the tin sheet by glue, and curing the glue; S3, connecting the conductive metal sheet and the plurality of LED chips into a path, coating glue on the tin sheet, and curing to obtain a first glue layer that wraps the tin sheet, the plurality of LED chips, and a portion of the conductive metal sheet; S4, reflow soldering the carrier together with the first glue layer and the conductive metal sheet, so that the tin sheet is melted and separated from the first glue layer, the plurality of LED chips, and the conductive metal sheet; S5. Apply glue on the back side of the LED chip to generate a back side glue layer, and obtain a substrate-free flexible filament after curing.

2. The production process of a substrate-free flexible filament according to claim 1, characterized in that: The carrier includes: an outer frame; a plurality of tin sheet support blocks are arranged on the inner side of the outer frame; a first limit block corresponding to the conductive metal sheet is arranged on the outer frame; a movable block is slidably arranged on the outer frame; a spring is arranged between the movable block and the outer wall of the outer frame; one end of the spring is fixed to the outer wall of the outer frame, and the other end is fixed to the movable block; a second limit block corresponding to the conductive metal sheet is arranged on the movable block.

3. The production process of a substrate-free flexible filament according to claim 2, characterized in that: The step of adhering the conductive metal sheet and a plurality of LED chips to the tin sheet by means of glue comprises: Adhere a plurality of LED chips to the tin sheet using die-bonding glue in a preset arrangement order; The positive conductive metal sheet is sleeved on the first limiting block, and the negative conductive metal sheet is sleeved on the second limiting block. The ends of the positive conductive metal sheet and the negative conductive metal sheet are bonded to the tin sheet by glue.

4. The production process of a substrate-free flexible filament according to claim 2 is characterized in that: The conductive metal sheet and the plurality of LED chips are connected to form a path, glue is coated on the tin sheet, and a first glue layer covering the tin sheet, the plurality of LED chips, and part of the conductive metal sheet is obtained after curing, including: Use conductive wires to connect the conductive metal sheet and several LED chips into a path; Applying a first glue on the tin sheet to cover the electrode surface of the LED chip, the tin sheet, and the ends of the positive conductive metal sheet and the negative conductive metal sheet; The first glue is baked and cured to obtain a first glue layer that wraps a plurality of LED chips, tin sheets, and ends of the positive conductive metal sheet and the negative conductive metal sheet.

5. The production process of a substrate-free flexible filament according to claim 2, characterized in that: The conductive metal sheet and the plurality of LED chips are connected to form a path, glue is coated on the tin sheet, and a first glue layer covering the tin sheet, the plurality of LED chips, and part of the conductive metal sheet is obtained after curing, including: Use conductive wires to connect the conductive metal sheet and several LED chips into a path; Apply glue above each LED chip on the tin sheet, the glue covers the LED chips and the conductive wires, and after curing, a second glue layer covering the LED chips and the conductive wires is obtained; The movable block on the outer frame is stretched to make the second glue flat, and glue is coated on the second glue layer by glue coating equipment. The glue covers the second glue layer, the tin sheet, and the ends of the positive conductive metal sheet and the negative conductive metal sheet. After curing, the first glue layer is obtained, which wraps the first glue layer, the tin sheet, and the ends of the positive conductive metal sheet and the negative conductive metal sheet.

6. The production process of a substrate-free flexible filament according to claim 1, characterized in that: The method of reflow soldering the carrier together with the first glue layer and the conductive metal sheet to melt the tin sheet and separate it from the first glue layer, the plurality of LED chips, and the conductive metal sheet comprises: The carrier is placed on a steel plate, and the steel plate is placed in a reflow soldering device to perform reflow soldering on the steel plate, wherein the reflow soldering temperature is set to 260° C. and the time is set to 60 seconds; The tin sheet is melted in the reflow soldering equipment and separated from the first glue layer, several LED chips, and the conductive metal sheet. The melted solder paste is collected in a steel tray.

7. The production process of a substrate-free flexible filament according to claim 1, characterized in that: After the back side of the LED chip is coated with glue to form a back side glue layer, and the back side glue layer is cured to obtain a substrate-free flexible filament, the method further includes: The substrate-free flexible filament is cut to obtain a substrate-free flexible filament of a predetermined width.

8. A substrate-free flexible filament, characterized in that: The flexible filament is manufactured by the production process of the substrate-free flexible filament as claimed in any one of claims 1 to 7.

9. A packaging structure of a flexible filament without a substrate, characterized in that: include: A first glue layer, a back glue layer, a positive conductive metal sheet, a negative conductive metal sheet, a number of LED chips, and a number of conductive wires corresponding to the number of LED chips; the number of LED chips and the number of conductive wires are correspondingly connected and conducted to form an LED chipset with conductive wires at both ends; the positive conductive metal sheet and the negative conductive metal sheet are respectively connected to the two ends of the LED chipset; the first glue layer covers the LED chipset, and part of the positive conductive metal sheet and the negative conductive metal sheet; the back glue layer is arranged on the back of the first glue layer.

10. A packaging structure of a flexible filament without a substrate, characterized in that: include: The first glue layer, the second glue layer, the back glue layer, the positive conductive metal sheet, the negative conductive metal sheet, a number of LED chips, and a number of conductive wires corresponding to the number of LED chips; the number of LED chips and the number of conductive wires are correspondingly connected and conducted to form an LED chipset with conductive wires at both ends; the positive conductive metal sheet and the negative conductive metal sheet are respectively connected to the two ends of the LED chipset; the second glue layer covers the LED chipset; the first glue layer covers the LED chipset, and part of the positive conductive metal sheet and the negative conductive metal sheet; the back glue layer is arranged on the back of the first glue layer.

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