Light-emitting diode (LED) device manufacturing method and LED device

Abstract

The present application relates to a light-emitting diode (LED) device manufacturing method and an LED device. The LED device manufacturing method comprises: eutectically bonding LED chips onto pads of a substrate, and placing a film in a light-emitting region of each LED chip (S1); adsorbing a release film onto an upper mold core of a mold pressing device (S2); placing the substrate on a lower mold core (S3); and clamping the upper mold core and the lower mold core, with the release film covering the surfaces of the films, and performing molding of a white reflective wall compound (S4).

Description

Preparation method of light emitting diode (LED) device and LED device

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on January 26, 2024, with application number 202410116364.X. The entire contents of this application are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of LED technology, for example, to a method for preparing an LED device and an LED device. Background Art

[0003] A light emitting diode (LED) is a semiconductor device that is a solid-state light-emitting device that can convert electrical energy into light energy. It has the advantages of small size, low power consumption, and long life, and is widely used in lighting, display, and communication fields.

[0004] Please refer to Figure 1. The LED device includes a substrate 1, an LED chip 2, a membrane 3 and white wall glue 4. The LED chip 2 is placed on the front of the substrate 1. The membrane 3 is bonded to the light-emitting area of ​​the LED chip 2 through an adhesive. The white wall glue 4 wraps the LED chip 2 and fits the front of the substrate 1. The surface of the white wall glue 4 is flush with the surface of the membrane 3.

[0005] In the related art, white glue 4 is typically applied to the substrate 1, LED chip 2, and membrane 3 through molding, and then the adhesive 4 covering the membrane 3 is removed through grinding and polishing. However, in LED devices manufactured using this method, a certain amount of separation occurs around the edges where the adhesive 4 and membrane 3 are bonded, and this separation is exacerbated after thermal shock tests. Summary of the Invention

[0006] The present application provides a method for preparing an LED device and an LED device.

[0007] The present application provides a method for preparing an LED device, comprising:

[0008] Eutectic LED chip on the pad of the substrate, and placing the membrane on the light emitting area of ​​the LED chip;

[0009] Adsorb the release film onto the upper mold core of the molding equipment;

[0010] placing the substrate on a lower mold core;

[0011] The upper mold core and the lower mold core are closed together, the release film covers the surface of the diaphragm, and the white wall glue is plastic-sealed.

[0012] In one embodiment, the release film is coated with a high-temperature adhesive layer, and the high-temperature adhesive layer contacts the diaphragm.

[0013] In one embodiment, the upper mold core is provided with a laminating unit; adsorbing the release film on the upper mold core of the molding equipment includes: unfolding the release film under the upper mold core through the laminating unit, and adsorbing the release film on the upper mold core.

[0014] In one embodiment, the distance difference between the surfaces of different membranes on the substrate and the front surface of the substrate is less than 50 μm.

[0015] In one embodiment, the upper mold core includes a plurality of movable blocks and a movable block control unit. The movable blocks are protruding from the upper mold core. The positions and numbers of the movable blocks correspond to the LED chips on the substrate. The movable block control unit is used to control the movement of the movable blocks.

[0016] In one embodiment, the movable block is circular.

[0017] In one embodiment, the area of ​​the movable block is greater than or equal to the area of ​​the membrane, and less than or equal to the area of ​​the LED device.

[0018] In one embodiment, the protruding height of the movable block is greater than the distance difference between different membranes on the substrate and the front surface of the substrate.

[0019] In one embodiment, the movable block control unit includes at least one cylinder, and the cylinder controls each movable block individually.

[0020] The present application also provides an LED device, comprising a substrate, an LED chip, a membrane and white wall glue, wherein the LED chip is arranged on the front side of the substrate, the membrane is arranged in the light-emitting area of ​​the LED chip, the white wall glue wraps the LED chip and is adhered to the front side of the substrate, the surface of the white wall glue around the membrane is lower than the white wall glue in other areas, and the surface of the membrane is flush with the surface of the white wall glue in other areas. The LED device is manufactured by any of the above methods for preparing an LED device.

[0021] The present application also provides an LED device, comprising a substrate, an LED chip, a membrane, and white wall glue, wherein the LED chip is arranged on the front side of the substrate, the membrane is arranged in the light-emitting area of ​​the LED chip, the white wall glue wraps the LED chip and is attached to the front side of the substrate, the surface of the white wall glue is lower than the surface of the membrane, and the surface of the white wall glue around the membrane is lower than the white wall glue in other areas. The LED device is obtained by the above-described method for preparing an LED device.

[0022] The present application also provides an LED device, comprising a substrate, an LED chip, a membrane, and white wall glue, wherein the LED chip is arranged on the front side of the substrate, the membrane is arranged in the light-emitting area of ​​the LED chip, the white wall glue wraps the LED chip and is attached to the front side of the substrate, the surface of the white wall glue around the membrane is lower than the white wall glue in other areas, and the surface of the white wall glue in other areas is higher than the surface of the membrane, and the LED device is obtained by the above-described method for preparing an LED device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 is a schematic structural diagram of an LED device in the related art;

[0024] FIG2 is a schematic diagram of molded white wall adhesive when the upper mold core is flat according to one embodiment of the present application;

[0025] FIG3 is a cross-sectional schematic diagram of an LED device according to an embodiment of the present application;

[0026] FIG4 is a schematic diagram of molding white wall adhesive when the upper mold core is provided with a protruding movable block according to one embodiment of the present application;

[0027] FIG5 is a cross-sectional schematic diagram of another LED device provided by the present application;

[0028] FIG6 is a cross-sectional schematic diagram of another LED device provided by the present application;

[0029] FIG7 is a schematic flow chart of a method for preparing an LED device according to an embodiment of the present application. DETAILED DESCRIPTION

[0030] The following describes the embodiments of the present application in conjunction with the accompanying drawings. Many details are set forth in the following description to facilitate understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the embodiments disclosed below.

[0031] Technicians analyzed the separation problem of white wall glue and diaphragm and found that a major factor affecting it is the grinding and polishing process of the white wall glue covering the upper part of the diaphragm. The grinding and polishing process can destroy the bonding strength between the diaphragm and the white wall glue, and can also cause other problems such as damage to the diaphragm. Based on this, the present application uses a release film adsorbed on the upper mold core of the molding equipment to mold the white wall glue. This can prevent the white wall glue from covering the upper surface of the diaphragm during plastic sealing, thus eliminating the need for grinding and polishing the diaphragm, avoiding damage to the diaphragm caused by grinding and polishing, and preventing separation at the junction of the white wall glue and the diaphragm.

[0032] The embodiments of the present application are described below with reference to the accompanying drawings.

[0033] Example 1

[0034] The method for preparing the LED device of the present application, as shown in FIG7 , includes the following steps.

[0035] Step S1: eutecticize an LED chip on a substrate and place a film on a light-emitting area of ​​the LED chip.

[0036] In step S1, an LED chip 11 is eutecticized on the soldering pad of the substrate 10, and a diaphragm 12 is placed in the light-emitting area of ​​the LED chip 11. Please refer to Figure 2. At least one soldering pad is provided on the substrate 10, at least one LED chip 11 is eutecticized on the soldering pad, and a diaphragm 12 is placed in the light-emitting area of ​​each LED chip 11. The diaphragm 12 can be a fluorescent diaphragm or a transparent diaphragm. When the LED device emits green, red, yellow, white or other colored light, a fluorescent diaphragm is used, and the blue light emitted by the LED chip 11 excites the fluorescent diaphragm to emit the corresponding light color; when the LED device emits monochromatic light such as blue, red, yellow-green or other monochromatic light, a transparent diaphragm is used, and the monochromatic light emitted by the LED chip 11 is emitted through the transparent diaphragm. In this embodiment, the diaphragm 12 is bonded to the LED chip 11 by an adhesive.

[0037] Step S2: adsorbing the release film onto the upper mold core of the molding equipment.

[0038] Referring to Figure 2 , the upper mold core 20 is flat and is equipped with a laminating unit. The laminating unit unrolls a release film 30 beneath the upper mold core 20 and adheres the release film 30 to the upper mold core 20. Exemplarily, the laminating unit includes a reel device configured to unroll the release film 30 beneath the upper mold core 20 and a vacuum pump configured to adhere the release film 30 to the upper mold core 20.

[0039] Step S3: placing the substrate and the colloid or powder of the white wall glue on the lower mold core of the molding equipment.

[0040] In this embodiment, the lower mold core of the molding device includes a mold cavity and a sleeve, the substrate 10 is placed in the mold cavity, and the colloid or powder of the white wall glue is placed in the sleeve. In step S3, the substrate 10 is placed in the lower mold core.

[0041] Step S4: close the upper mold core and the lower mold core, cover the surface of the membrane with a release film, and seal the white wall glue.

[0042] After the upper and lower mold cores are closed, the colloid or powder in the sleeve changes from solid to liquid under the action of temperature and rotation pressure, and is injected onto the surface of the substrate 10 through the flow channel of the lower mold core, completing the plastic sealing of the white wall glue 13.

[0043] After the upper and lower mold cores are closed, the release film covers the diaphragm, which can prevent the white wall glue from covering the upper surface of the diaphragm during the plastic sealing. In this embodiment, a high-temperature adhesive layer is coated on the release film, and the high-temperature adhesive layer contacts the diaphragm. On the one hand, because the diaphragm is obtained by cutting the entire surface of the diaphragm during preparation, the pressure of the cutting tool during the cutting process will cause the edge of the diaphragm to have jagged edges, such as cracked edges, so that the edge and the center of the diaphragm are not in the same plane, and there is a height difference. When the white wall glue is plastic sealed, if no high-temperature adhesive is added and the diaphragm is only contacted through the release film, the thickness of the release film needs to be increased to compensate for this height difference. On the other hand, if no high-temperature adhesive is added and the diaphragm is only contacted through the release film, a large pressure needs to be applied to the release film to cause the release film to deform so that the release film can fully contact the upper surface of the diaphragm. However, the deformation of the release film is limited, and too much pressure on the equipment may cause damage to the chip. Therefore, in this embodiment, the high-temperature adhesive layer is applied to ensure good contact between the release film and the diaphragm.

[0044] Because the upper mold core is flat, the distance from the entire release film to the substrate remains constant after the upper and lower mold cores are joined. However, if the substrate has multiple solder pads, the height of the LED chip and the film on each pad—that is, the distance between the film surface and the front of the substrate—may vary. If the distance difference between the film surface and the front of the substrate is too large, the white wall adhesive may cover part of the film surface. Therefore, in this embodiment, the distance difference between the surfaces of different film sheets and the front of the substrate is less than 10 μm.

[0045] Referring to Figures 1, 3, and 5, unlike the related art where the surface of white wall glue 4 is flush with the surface of diaphragm 3, the LED device produced by the LED device manufacturing method of the present application has white wall glue 13 around diaphragm 12 that is concave, meaning the surface of white wall glue 13 around diaphragm 12 is lower than that of white wall glue 13 in other areas. Except for the area around diaphragm 12, the surface of white wall glue 13 in other areas is flush with the surface of diaphragm 12 (as shown in Figure 5) or lower than the surface of diaphragm 12 (as shown in Figure 3).

[0046] Compared with the related art, the present application first adsorbs the release film on the upper mold core and then molds the white wall glue, which can avoid the white wall glue covering the upper surface of the membrane during plastic sealing, thereby eliminating the need to grind or polish the membrane, avoiding damage to the membrane caused by grinding and polishing, and preventing separation at the junction of the white wall glue and the membrane.

[0047] Example 2

[0048] The preparation method of the second embodiment is substantially the same as that of the first embodiment, with the only difference being the upper mold core structure and step S4.

[0049] Please refer to Figure 4. The upper mold core 20 also includes a plurality of movable blocks 202 and a movable block control unit. The movable blocks 202 are protruding from the upper mold core 20. The positions and numbers of the movable blocks 202 correspond to the diaphragm 12 on the substrate 10. The movable block control unit is configured to control the movement of the movable blocks 202.

[0050] The protruding height of the movable block 202 is greater than the distance difference between different diaphragms 12 on the substrate 10 and the front of the substrate 10, thereby ensuring that the movable block 202 can contact the upper surface of all diaphragms 12. The upper mold core 20 is provided with a coating unit. Exemplarily, the coating unit unfolds the release film 30 below the upper mold core 20 and adsorbs the release film 30 on the upper mold core 20. At this time, the bottom of the movable block 202 is covered with the release film 30, and all the movable blocks 202 are in a protruding state. In step S4, when the upper and lower mold cores are closed, due to the height difference between the surfaces of different diaphragms 12 and the front of the substrate 10, some of the movable blocks 202 will first contact the upper surface of the diaphragm 12. At this time, the other movable blocks 202 fail to contact the upper surface of the diaphragm 12. The movable block control unit controls the movable blocks 202 that have contacted the upper surface of the diaphragm 12 to move upward, and at the same time, the movable block control unit controls these movable blocks 202 to always keep in contact with the upper surface of the diaphragm 12. When all the movable blocks 202 contact the upper surface of the diaphragm 12, the upper and lower mold cores are closed. The colloid or powder of the white wall glue 13 is placed on the lower mold core to plastic-seal the white wall glue 13.

[0051] The movable block 202 is circular. On the one hand, a circular movable block 202 is easier to process. On the other hand, a circular shape eliminates sharp corners, preventing the movable block 202 from cutting through the release film 30 and causing adhesive leakage. In this embodiment, the area of ​​the movable block 202 is greater than or equal to the area of ​​the diaphragm 12 and less than or equal to the area of ​​the LED device. This allows the movable block 202 to completely cover the upper surface of the diaphragm 12, preventing the white wall glue 13 from covering the upper surface of the diaphragm 12 during plastic sealing.

[0052] As shown in Figure 4, the length of a single diaphragm 12 is a, the diameter of a single movable block 202 is b, the shortest distance between the movable block 202 and the edge of the upper mold core 20 is c, the spacing between adjacent movable blocks 202 is d, the length of a single LED device is e, and the width of the cut path on the substrate 10 is f. Both a and e must be determined based on the performance requirements of the LED device. The size of a single movable block 202 must satisfy the following: a ≤ b ≤ e. This can be adjusted based on the machine accuracy of the upper mold core of the eutectic machine, film laminating machine, and laminator. The width of the cut path on the substrate 10 is the width of the cutting blade. The choice of cutting blade depends on the substrate material, product structure, and cost considerations. Generally, f is between 0.06 and 0.3 mm. In one embodiment, e = 3a, b = 2a, f = 0.2a, c = 0.6a, and d = 2c.

[0053] The movable block control unit is a cylinder, and the cylinder controls each movable block 202 individually. The number of cylinders can be at least one. Since the distance between the surface of different diaphragms 12 on the substrate 10 and the front of the substrate 10 is different, by individually controlling the cylinders, it is possible to avoid the upper surface of the diaphragm 12 being covered by the white wall glue 13, thereby improving the production yield of the LED device. Therefore, this embodiment is applicable to situations where the distance difference between the surface of different diaphragms 12 on the substrate 10 and the front of the substrate 10 is large. For example, the distance difference between the surface of different diaphragms 12 on the substrate 10 and the front of the substrate 10 is less than 50 μm.

[0054] The present application can have various variations. For example, the movable block 202 can be shaped like a curved polygon or other non-angular structure, as long as it can cover the upper surface of the membrane 12. In addition, when the difference in distance between the surfaces of different membranes 12 on the substrate 10 and the front surface of the substrate 10 is less than 10 μm, a single cylinder can be used to control them.

[0055] Similar to Example 1, the LED device fabricated in Example 2 has a recessed white adhesive 13 surrounding the membrane 12, meaning the surface of the white adhesive 13 surrounding the membrane 12 is lower than that of the white adhesive 13 in other areas. In Example 2, each movable block 202 contacts the surface of a single membrane 12, and there is a distance difference between the surfaces of different membranes 12 and the front surface of the substrate 10. Therefore, except for the area surrounding the membrane 12, the surface of the white adhesive 13 in other areas is flush with the surface of the membrane 12 (as shown in FIG. 5 ) or higher than the surface of the membrane 12 (as shown in FIG. 6 ).

[0056] The present application provides an LED device, comprising a substrate 10, an LED chip 11, a diaphragm 12, and white wall glue 13, wherein the LED chip 11 is disposed on the front surface of the substrate 10, the diaphragm 12 is disposed in the light-emitting area of ​​the LED chip 11, the white wall glue 13 wraps around the LED chip 11 and is bonded to the front surface of the substrate 10, the surface of the white wall glue 13 around the diaphragm 12 is lower than the white wall glue 13 in other areas, and the surface of the diaphragm 12 is flush with the surface of the white wall glue 13 in other areas (as shown in FIG5 ), and the LED device is manufactured by any of the above methods for manufacturing an LED device. The diaphragm 12 covers the top of the LED chip 11, and it can be understood that the light-emitting area of ​​the LED chip 11 is the area above the LED chip 11.

[0057] The present application also provides an LED device, including a substrate 10, an LED chip 11, a membrane 12 and white wall glue 13. The LED chip 11 is arranged on the front side of the substrate 10, the membrane 12 is arranged in the light-emitting area of ​​the LED chip 11, the white wall glue 13 wraps the LED chip 11 and is attached to the front side of the substrate 10, the surface of the white wall glue 13 is lower than the surface of the membrane 12, and the surface of the white wall glue 13 around the membrane 12 is lower than the white wall glue 13 in other areas (as shown in Figure 3). The LED device is obtained by the above method for preparing the LED device.

[0058] The present application also provides an LED device, including a substrate 10, an LED chip 11, a membrane 12 and white wall glue 13. The LED chip 11 is arranged on the front side of the substrate 10, the membrane 12 is arranged in the light-emitting area of ​​the LED chip 11, the white wall glue 13 wraps the LED chip 11 and is attached to the front side of the substrate 10, the surface of the white wall glue 13 around the membrane 12 is lower than the white wall glue 13 in other areas, and the surface of the white wall glue 13 in other areas is higher than the surface of the membrane 12 (as shown in Figure 6). The LED device is obtained by the above method for preparing the LED device.

[0059] The multiple technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the multiple technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The above-described embodiments merely represent several implementation methods of the present application and should not be construed as limiting the scope of the patent application. A person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present application, and all such modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A method for preparing a light-emitting diode (LED) device, comprising: Eutectically bonding an LED chip on a pad of a substrate, and placing a diaphragm on the light-emitting area of the LED chip; Adsorbing a release film on an upper die core of a molding device; Placing the substrate on a lower die core; Closing the upper die core and the lower die core, with the release film covering the surface of the diaphragm, and encapsulating white wall glue.

2. The method according to claim 1, wherein The release film is coated with a high-temperature glue layer, and the high-temperature glue layer contacts the diaphragm.

3. The method according to any one of claims 1 to 2, wherein The upper die core is provided with a film covering unit; the step of adsorbing the release film on the upper die core of the molding device includes: unfolding the release film below the upper die core through the film covering unit, and adsorbing the release film on the upper die core.

4. The method according to claim 3, wherein, The distance difference between the surface of different diaphragms on the substrate and the front surface of the substrate is less than 50 μm.

5. The method according to claim 3, wherein, The upper die core includes a plurality of movable blocks and a movable block control unit. The movable blocks protrude from the upper die core, and the positions and numbers of the movable blocks correspond to the LED chips on the substrate; the method further includes: controlling the movement of the movable blocks through the movable block control unit.

6. The method according to claim 5, wherein, The movable blocks are circular.

7. The method according to claim 5, wherein, The area of the movable blocks is greater than or equal to the area of the diaphragm and less than or equal to the area of the LED device.

8. The method according to claim 5, wherein The height by which the movable blocks protrude from the upper die core is greater than the distance difference between different diaphragms on the substrate and the front surface of the substrate.

9. The method according to claim 5, wherein, The movable block control unit includes at least one cylinder; the method further includes: individually controlling each movable block through the cylinder.

10. A light-emitting diode (LED) device, comprising a substrate, an LED chip, a diaphragm and white wall glue. The LED chip is disposed on the front surface of the substrate. The diaphragm is disposed in the light-emitting area of the LED chip. The white wall glue wraps the LED chip and adheres to the front surface of the substrate, wherein, The surface of the white wall glue around the diaphragm is lower than the surface of the white wall glue in other areas, and the surface of the diaphragm is flush with the surface of the white wall glue in other areas. The LED device is obtained by the method for preparing an LED device according to any one of claims 1 to 9.

11. A light-emitting diode (LED) device, comprising a substrate, an LED chip, a diaphragm, and a white wall adhesive. The LED chip is disposed on the front surface of the substrate. The diaphragm is disposed in the light-emitting region of the LED chip. The white wall adhesive wraps the LED chip and adheres to the front surface of the substrate. Among them, The surface of the white wall glue is lower than the surface of the diaphragm, and the surface of the white wall glue around the diaphragm is lower than the surface of the white wall glue in other areas. The LED device is obtained by the method for preparing an LED device according to any one of claims 1 to 4.

12. A light-emitting diode (LED) device, comprising a substrate, an LED chip, a diaphragm, and a white wall adhesive. The LED chip is disposed on the front surface of the substrate. The diaphragm is disposed in the light-emitting region of the LED chip. The white wall adhesive wraps the LED chip and adheres to the front surface of the substrate, wherein, The surface of the white wall glue around the diaphragm is lower than the surface of the white wall glue in other areas, and the surface of the white wall glue in other areas is higher than the surface of the diaphragm. The LED device is obtained by the method for preparing an LED device according to any one of claims 5 to 9.

Images