A blanking type EMC5050 LED support and a manufacturing method thereof

Abstract

The application discloses a blanking type EMC5050 LED support and a manufacturing method thereof. The support comprises a metal lead frame strip and an EMC injection body. The metal lead frame strip is provided with a plurality of support units arranged in an array. Each support unit is independently connected to the strip through a connecting rib. A transition area between the connecting rib and the support unit is provided with a pre-breaking weakened micro groove. The EMC injection body is wrapped on the metal lead frame to form a support body. The EMC injection body does not penetrate into the pre-breaking weakened micro groove. The injection mold is provided with a sealing boss at a position corresponding to the pre-breaking weakened micro groove. The height of the sealing boss matches the thickness of the connecting rib. The application realizes metal pad detection before injection molding and three-stage online sampling through the process sequence of "blanking first and then injection molding", combined with a selective surface roughening process and a pre-breaking weakened micro groove anti-penetration design. The cutting stress after injection molding is eliminated, and the product reliability and yield are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor LED packaging technology, and in particular to a drop-type EMC5050 LED bracket and its manufacturing method. Background Technology

[0002] The LED package bracket is the core structural component of an LED device, directly determining the chip's heat dissipation performance, optical light extraction efficiency, and product reliability. Currently, the two core plastic materials of the EMC5050 LED bracket are both EMC (epoxy molding compound), with an embedded metal lead frame providing electrical connections and heat dissipation channels. The traditional etched integrated EMC5050 bracket is currently the most common mass production solution. Its typical process flow is: metal plate - chemical etching to create an integrated frame - injection molding - cutting / dicing - electroplating. This solution involves chemically etching multiple interconnected frame units onto a single metal plate, i.e., the lead frame, first performing overall injection molding, and finally using specialized cutting equipment to cut the packaged assembly into individual LED chips.

[0003] Traditional etched integrated EMC5050 LED brackets have the following problems: First, online sampling inspection is impossible. After injection molding, traditional etched integrated brackets are a single, continuous structure. Individual bracket units cannot be independently removed for sampling inspection without damaging the overall structure. Final inspection can only be carried out after packaging and separation into individual devices. The intermediate quality status of core processes such as die bonding, wire bonding, and dispensing cannot be monitored through sampling inspection. Second, bottom inspection is impossible. The bottom of traditional etched integrated brackets, i.e., the chip mounting surface and the surface containing the metal pads, is sealed as a single continuous structure by EMC material after injection molding. Before packaging, it is impossible to independently inspect the morphology, flatness, oxidation, and solderability of the bottom pads of individual bracket units. Third, batch process monitoring is impossible. Due to the above two limitations, traditional etched integrated brackets lack effective online process quality control methods throughout the entire LED packaging process. SPC (Statistical Process Control) cannot obtain real-time quality data for key processes, and fluctuations in product yield cannot be effectively controlled. Fourth, post-injection molding cutting introduces stress that affects reliability. Traditional etched integrated substrates separate the units by cutting after injection molding. The cutting operation inevitably introduces mechanical and thermal stress, which may lead to problems such as broken bonding wires of the packaged chip, cracked die bond layer, and microcracks in the package.

[0004] Therefore, existing technologies have shortcomings and need to be improved. Summary of the Invention

[0005] The technical problem to be solved by the embodiments of the present invention is that the traditional etched integrated EMC5050 bracket in the prior art cannot achieve online sampling, bottom inspection and process batch monitoring, and the published literature does not provide a complete technical solution that systematically integrates "bracket structure with blanking before injection molding", "selective surface roughening process", "pre-break weakening micro-groove parameter optimization" and "three-level online sampling + SPC closed-loop control".

[0006] To address the aforementioned issues, this invention provides a blanking-type EMC5050 LED bracket, comprising a metal lead frame strip and an EMC injection molded body. The metal lead frame strip has multiple bracket units arranged in an array, each bracket unit being independently connected to the strip via a connecting rib. A pre-break weakening microgroove is provided in the transition area between the connecting rib and the bracket unit. The EMC injection molded body wraps around the metal lead frame to form the bracket body, and the EMC injection molded body does not penetrate into the pre-break weakening microgroove. A sealing boss is provided at the corresponding position of the pre-break weakening microgroove in the injection mold, and the height of the sealing boss matches the thickness of the connecting rib.

[0007] In some embodiments, the pre-break weakening microgroove is V-shaped or U-shaped, with a width of 0.05 mm to 0.15 mm and a depth of 40% to 60% of the metal strip thickness.

[0008] In some embodiments, each of the support units is a dual-cavity structure, comprising a first functional cavity and a second functional cavity arranged side by side, with a middle partition between the two cavities; the support units are arranged on the material belt in a matrix of 12 rows × 24 columns.

[0009] In some embodiments, the metal lead frame strip is made of copper alloy or iron-nickel alloy strip.

[0010] In some embodiments, the width of a single functional cavity of the dual-cavity body is 1.99±0.10mm, the total width of the dual-cavity body is 4.24±0.10mm, and the thickness of the intermediate partition is 0.24±0.05mm.

[0011] This invention also provides a method for manufacturing a drop-type EMC5050 LED bracket, comprising the following steps: S1. Chemical etching is performed on the metal strip to form a lead frame pattern; S2. A strip with connecting ribs and pre-broken weakening microgrooves is formed by stamping and separating through a blanking die. Each support unit is independently suspended on the strip through the connecting ribs. S3. Use photomask technology to selectively roughen the metal surface of the EMC-enclosed area, while leaving the pad area unroughened. S4. EMC injection molding is performed through an injection mold, wherein the injection mold is provided with a sealing and fitting structure at the corresponding position of the pre-fracture weakening microgroove to prevent EMC melt from penetrating into the pre-fracture weakening microgroove. S5. Perform electroplating treatment.

[0012] In some embodiments, the selective roughening process in step S3 specifically involves: covering the pad area with a photosensitive protective film, exposing only the EMC-encapsulated area, and then immersing the masked strip in a chemical roughening solution for roughening treatment, so that the surface roughness Ra of the metal in the EMC-encapsulated area reaches 0.8 μm to 1.5 μm; after roughening, removing the protective film from the pad area, the metal surface of the pad area remains in its original smooth state, and the surface roughness Ra is less than 0.2 μm after subsequent electroplating.

[0013] In some embodiments, the chemical roughening solution is an acidic oxidation system, the roughening temperature is 30°C to 40°C, and the processing time is 30 seconds to 90 seconds.

[0014] In some embodiments, an online sampling inspection step is further included after step S3. The online sampling inspection includes a three-level system: Level 1, before injection molding, the solderability of the pads and the bottom morphology of a single metal support unit are tested; Level 2, after die bonding, 3 to 5 units are removed from the strip every 500 units to test the die bonding position accuracy, silver paste coverage and chip cracks; Level 3, after wire bonding, 3 to 5 units are removed every 500 units to test the push-pull force and inspect the wire bonding morphology.

[0015] In some embodiments, the electroplating process in step S5 involves sequentially plating a barrier layer and a reflective layer, wherein the thickness of the barrier layer is 1.5 μm to 2.0 μm and the thickness of the reflective layer is 2.0 μm to 3.0 μm.

[0016] Compared with the prior art, the technical effects achieved by the embodiments of the present invention include: This invention provides a structural basis for independently usable units through a "pre-feeding and post-injection molding" approach, enabling selective coarsening, i.e., precise masking of exposed pad areas before injection molding, and making three-level online sampling, i.e., usable metal units before injection molding, feasible. It also allows for precise forming of pre-cut microgrooves in their metallic state before injection molding. At the same time, selective coarsening enhances EMC bonding strength and compensates for the potential problem of insufficient EMC-metal bonding strength that may arise from "pre-feeding and post-injection molding". The mold sealing structure solves the technical problem of EMC filling of pre-cut microgrooves under high-pressure injection molding environment. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0020] Figure 1 This is a structural diagram of the metal lead frame strip of the blanking type EMC5050 LED bracket of the present invention.

[0021] Figure 2 for Figure 1 Enlarged view of point A in the middle. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Similar component reference numerals in the drawings represent similar components. Obviously, the embodiments described below are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0023] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0024] It should also be understood that the terminology used in this specification of embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of the invention. As used in this specification of embodiments of the invention and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0025] like Figure 1-2 As shown, an embodiment of the present invention, the drop-type EMC5050 LED bracket, is a continuous strip structure, and the whole is in the shape of a long strip plate. It includes a metal lead frame strip 1, an EMC injection body, a connecting rib structure 6, a positioning and conveying structure, and a pre-break weakening structure 7.

[0026] Specifically, the metal lead frame strip 1 is formed from copper alloy or iron-nickel alloy strip through chemical etching and blanking stamping, and has an overall elongated flat structure. The total length L of the strip is 158.40±0.15mm, and the length L1 of the effective support unit 2 arrangement area is 151.80±0.10mm; the total width W of the strip is 75.00±0.10mm, and the width W1 of the effective support unit 2 arrangement area is 72.00±0.08mm; the thickness of the metal strip is 0.25±0.02mm. Process edges are provided on the top and bottom sides of the strip for equipment clamping, conveying, and positioning.

[0027] Multiple support units 2 are evenly arranged in a matrix of 12 rows × 24 columns within the effective area of ​​the material strip, totaling 288 support units 2 / strip. The longitudinal row spacing P1 is 5.6 mm, and the transverse column spacing P2 is 6.6 mm. The external dimensions of each support unit 2 are (5.10±0.10) mm × (5.00±0.10) mm. Each support unit 2 has a double-cavity structure, namely a cup-shaped area, containing a first functional cavity 3 and a second functional cavity 4 arranged side by side, with a partition 5 between the two cavities. The partition thickness D is 0.24±0.05 mm. The width W2 of a single functional cavity is 1.99±0.10 mm, and the total width W3 of the double cavity is 4.24±0.10 mm. The sidewall thickness of the support unit 2 is 0.70 mm.

[0028] After blanking and stamping, each support unit 2 is connected to adjacent support units 2 and the strip process frame via connecting ribs 6. The width of the connecting ribs 6 is 0.30mm to 0.60mm, preferably 0.45mm. A pre-break weakening structure 7 is provided in the transition area between the connecting ribs 6 and the support units 2. This pre-break weakening structure 7 is directly formed by the die during blanking and stamping, and is a V-shaped or U-shaped pre-cut micro-groove. The width of the micro-groove is 0.05mm to 0.15mm, preferably 0.10mm, and the depth is 40% to 60% of the strip thickness, preferably 50%, i.e., 0.125mm. The tensile strength of the connecting ribs 6 in the metallic state is greater than 15N, ensuring the integrity of the strip structure in subsequent injection molding, electroplating, and encapsulation processes.

[0029] During subsequent EMC injection molding, the injection pressure is typically between 80 MPa and 120 MPa. EMC melt may seep into the pre-fractured microgroove, causing it to fill completely. This results in a decreased fracture quality during final inspection, potentially leading to the removal of EMC debris or a significant increase in separation force. To address this issue, this invention incorporates a sealing and bonding structure (not shown) at a corresponding location on the injection mold. In the area of ​​the pre-fractured microgroove, the mold cavity surface of the injection mold is tightly fitted to the area of ​​the connecting rib 6, with a bonding gap of less than 0.02 mm. This utilizes the physical sealing effect of the mold cavity surface to prevent EMC melt from entering the pre-fractured microgroove. This sealing and bonding structure is achieved by setting a protruding sealing boss in the corresponding area of ​​the mold. Its height matches the thickness of the connecting rib 6, and its width covers the pre-fractured microgroove area and at least 0.1 mm on each side. After injection molding, the pre-fractured microgroove remains empty and unfilled by EMC, ensuring a clean fracture without EMC debris during final inspection.

[0030] Furthermore, positioning hole groups 8 are provided on the upper and lower process edges of the strip body, including two different diameter positioning holes: a large hole with a diameter of 1.50 mm and a small hole with a diameter of 1.20 mm. The first positioning hole is 3.30 mm away from the edge of the strip end, and the positioning holes are arranged at equal intervals along the longitudinal direction of the strip. The positioning holes are formed simultaneously during the etching process and are used for precise positioning and stepping transport of subsequent blanking molds, injection molding machines, packaging equipment, etc. Each support unit 2 has a metal lead frame with pins for electrical connection and heat dissipation, and the pins extend from the outside of the support unit 2 to the process edge area of ​​the strip. The pad area is located at the bottom of the functional cavity. The metal substrate is preferably C7025 copper alloy or 42 iron-nickel alloy.

[0031] EMC material is used to encapsulate a metal lead frame through injection molding to form the support body. To enhance the bonding between EMC and the metal, this invention performs selective surface roughening on the metal strip after blanking and stamping. "Selective roughening" means that only the metal surface of the EMC injection-molded area, i.e., the support body area, is roughened, while the pad area, i.e., the bottom of the functional cavity, is not roughened or only slightly roughened before electroplating to restore the plating surface to smoothness. Specifically, a photomask process is used to cover the pad area with a protective film, exposing only the EMC encapsulation area. Then, a chemical roughening solution is used to roughen the exposed area, achieving a surface roughness Ra of 0.8 μm to 1.5 μm in the EMC encapsulation area, forming a micro-rough structure for mechanical interlocking with the EMC resin. After roughening, the protective film in the pad area is removed, leaving the metal surface in the pad area with its original smooth state, Ra less than 0.3 μm. After electroplating, the surface roughness Ra of the silver plating layer in the pad area is less than 0.2μm, ensuring good adhesion and heat dissipation between the chip and the pad during die bonding. Meanwhile, the newly formed cut surface generated by the blanking stamping is located in the area of ​​connecting rib 6. This area is enclosed by EMC during injection molding. Therefore, the roughening of the cut surface at the blanking point can be completed in the selective roughening process. The connecting rib 6 area is part of the EMC-enclosed area and is included within the roughening range, ensuring that there are no weak areas in the EMC-metal bonding force.

[0032] As some embodiments, the present invention provides a method for manufacturing a drop-type EMC5050 LED bracket, comprising the following steps: Step S1: Metal strip preparation and etching. C7025 copper alloy coil, 0.25mm thick, is selected. The coil surface is pretreated by degreasing and acid pickling activation. The lead frame pattern is transferred to both sides of the metal strip through a film lamination, exposure, and development process. Then, a chemical etching solution—copper chloride acidic etching solution—is used to etch the complete lead frame pattern, including the support unit shape, dual-cavity structure, lead traces, positioning holes, connecting rib areas, and pre-cut weakening microgroove preparation positions. The etching accuracy is ±0.02mm. After etching, the photosensitive film is removed.

[0033] Step S2: Blanking and Stamping. The etched metal strip is fed into a precision blanking die. The die guide pin passes through the positioning hole for precise positioning. The blanking die performs the following actions: a) Stamping a V-shaped pre-cut micro-groove in the transition area between the connecting rib and the support unit, with a width of 0.10mm, a depth of 0.125mm (50% of the material thickness), and an opening angle of 60°; b) Stamping and separating along the outer contour of the support unit, retaining the connecting rib, with a width of 0.45mm, so that the unit is suspended on the strip; c) Cutting into single strips at a set length of 158.40mm. After blanking, each metal unit is independently suspended by the connecting rib, and the bottom pads are fully exposed. The tensile strength of the connecting rib in the metallic state is greater than 15N.

[0034] Step S3: Selective Surface Roughening. Selective roughening is performed on the blanked metal strip: Masking Step - A photosensitive protective film is applied to the pad area of ​​the metal strip, i.e., the bottom area of ​​the functional cavity, exposing only the EMC-encapsulated area, specifically the support body area, including sidewalls, partitions, and the outer side of the connecting ribs. The connecting rib area is within the EMC-encapsulated range and is not covered by the protective film. The blanking cut surface, i.e., the newly formed cross-section at the connecting rib, is also included in the exposure range; Roughening Step - The masked strip is immersed in a chemical roughening solution - an acidic oxidation system, specifically 80g / L ammonium persulfate + 50mL / L sulfuric acid, at a temperature of 30℃ to 40℃ for 30 to 90 seconds, roughening the exposed metal surface to form a micro-rough structure. After roughening, the surface roughness Ra of the metal in the EMC-encapsulated area reaches 0.8μm to 1.5μm; Film Removal Step - The photosensitive protective film in the pad area is removed, restoring the metal surface in the pad area to its original roughness after etching, with Ra less than 0.3μm.

[0035] Step S4: Injection Molding. The selectively roughened metal strip is fed into a precision injection molding machine. A key design feature of the injection mold is the presence of a sealing boss at the corresponding position of the pre-broken weakened microgroove. The height of the sealing boss matches the thickness of the connecting rib, approximately 0.25mm, and its width covers the pre-broken microgroove area and at least 0.1mm on each side. When the mold closes, the gap between the cavity surface and the connecting rib area is less than 0.02mm. Under injection pressures of 80MPa to 120MPa, the sealing boss effectively prevents EMC melt from penetrating into the pre-broken microgroove. The EMC material encapsulates the metal lead frame to form the support body, i.e., a double-cavity cup structure. The EMC resin penetrates into the microscopic rough structure of the roughened area, forming a strong mechanical interlocking bond. Injection parameters: material temperature 170℃ to 190℃, mold temperature 160℃ to 175℃.

[0036] Step S5: Electroplating. The injection-molded strip is sequentially plated with a barrier layer, specifically a nickel plating layer with a thickness of 1.5 μm to 2.0 μm, and a reflective layer, specifically a silver plating layer with a thickness of 2.0 μm to 3.0 μm. The surface roughness Ra of the solder pad area after silver plating is less than 0.2 μm. An organic anti-oxidation protective film is then applied.

[0037] Step S6: Three-level online sampling inspection. First level, completed before injection molding: After selective roughening in step S3, solderability testing and 3D morphology measurement are performed on individual metal units on the strip. 5 to 10 units are sampled according to the AQL sampling plan to check solder coverage (specifically, greater than 95%) and pad flatness. Second level, after die bonding: In the LED packaging die bonding process, 3 to 5 die-bonded units are removed from the strip for every 500 units to check die bonding position accuracy, silver paste coverage, and chip cracks. Data is entered into the SPC system. Third level, after wire bonding: 3 to 5 wire-bonded units are randomly sampled for every 500 units to perform push-pull force testing and wire bonding morphology inspection. Data is entered into the SPC system. An automatic warning is triggered when the process capability index (CPK) falls below 1.33.

[0038] Step S7: Final Inspection and Separation. After passing the final inspection of photoelectric performance, individual LED devices are separated from the strip along the pre-broken weakened microgrooves. Since the microgrooves remain empty and are not filled with EMC, the separation results in a clean break without EMC debris.

[0039] The blanking-type EMC5050 LED bracket manufactured using the method of this invention fully exposes the bottom pads of each metal unit after blanking and before injection molding, allowing for direct morphology inspection, plating inspection, and solderability assessment. Compared to traditional etching-integrated solutions, this shifts the quality control checkpoint from "final packaging inspection" to "pre-injection molding," enabling the detection and interception of pad-related quality issues before injection molding. Based on the "blanking before injection molding" bracket structure, a three-level online sampling inspection system is established, consisting of pre-injection molding pad inspection, post-die bonding sampling inspection, and post-wire bonding sampling inspection. The sampling data is uniformly integrated into the SPC system to form a closed-loop control. An automatic warning is issued when the process capability index (CPK) falls below 1.33, significantly improving the stability and consistency of product yield. Since blanking is completed before injection molding, the EMC package after injection molding no longer undergoes any cutting or separation operations, fundamentally eliminating the damage to the wire bonding, die bonding layer, and encapsulant caused by cutting stress. High and low temperature cycling and damp heat aging reliability tests show that the failure rate of blanking-type products is significantly lower than that of traditional etched integrated products. The selective roughening process only roughens the metal surface of the EMC-encapsulated area, forming an EMC-metal mechanical interlock structure, which significantly improves the bonding strength. At the same time, the pad area remains smooth, ensuring the quality of die bonding. This solves the contradiction between roughening to enhance bonding strength and pad flatness. Through the injection mold sealing and bonding structure, EMC melt is effectively prevented from penetrating into the pre-fractured microgroove under injection pressure of 80MPa to 120MPa, keeping the microgroove empty. After final inspection, the fracture is clean and no EMC debris is brought out, ensuring the realization of the "easy separation" advantage. The blanking process only requires a precision blanking mold, eliminating the need for expensive laser cutting machines or precision scribing machines, greatly reducing equipment investment. The high blanking and stamping speed is suitable for continuous large-scale production, significantly reducing overall manufacturing costs. The "blanking before injection molding" method provides a structural basis for independently usable units, making selective coarsening (i.e., precise masking of exposed pad areas before injection molding) feasible, enabling three-level online sampling (i.e., usable metal units before injection molding), and allowing precise forming of pre-cut microgrooves in their metallic state before injection molding. At the same time, selective coarsening enhances EMC bonding strength, compensating for the potential problem of insufficient EMC-metal bonding strength that may arise from "blanking before injection molding". The mold sealing structure solves the technical problem of EMC filling of pre-cut microgrooves under high-pressure injection molding environment. The various features support and reinforce each other, producing technical effects that go beyond the simple superposition of features.

[0040] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0041] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0042] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0043] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0044] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0045] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0046] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Since these modifications and variations fall within the scope of the claims and their equivalents, this invention also intends to include these modifications and variations.

[0047] The above description describes specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A drop-type EMC5050 LED bracket, characterized in that: The device includes a metal lead frame strip and an EMC injection molded body. The metal lead frame strip has multiple support units arranged in an array. Each support unit is independently connected to the strip via a connecting rib. A pre-break weakening microgroove is provided in the transition area between the connecting rib and the support unit. The EMC injection molded body wraps around the metal lead frame to form a support body, and the EMC injection molded body does not penetrate into the pre-break weakening microgroove. The injection mold has a sealing boss at the corresponding position of the pre-break weakening microgroove, and the height of the sealing boss matches the thickness of the connecting rib.

2. The blanking type EMC5050 LED bracket according to claim 1, characterized in that: The pre-break weakening microgroove is V-shaped or U-shaped, with a width of 0.05 mm to 0.15 mm and a depth of 40% to 60% of the metal strip thickness.

3. The blanking type EMC5050 LED bracket according to claim 1, characterized in that: Each of the support units is a dual-cavity structure, comprising a first functional cavity and a second functional cavity arranged side by side, with a middle partition between the two cavities; the support units are arranged on the material belt in a matrix of 12 rows × 24 columns.

4. The blanking type EMC5050 LED bracket according to claim 1, characterized in that: The metal lead frame strip is made of copper alloy or iron-nickel alloy strip.

5. The blanking type EMC5050 LED bracket according to claim 3, characterized in that: The width of a single functional cavity in the dual-cavity body is 1.99±0.10mm, the total width of the dual cavities is 4.24±0.10mm, and the thickness of the intermediate partition is 0.24±0.05mm.

6. A method for manufacturing a drop-type EMC5050 LED bracket, characterized in that: Includes the following steps: S1. Chemical etching is performed on the metal strip to form a lead frame pattern; S2. A strip with connecting ribs and pre-broken weakening microgrooves is formed by stamping and separating through a blanking die. Each support unit is independently suspended on the strip through the connecting ribs. S3. Use photomask technology to selectively roughen the metal surface of the EMC-enclosed area, while leaving the pad area unroughened. S4. EMC injection molding is performed through an injection mold, wherein the injection mold is provided with a sealing and fitting structure at the corresponding position of the pre-fracture weakening microgroove to prevent EMC melt from penetrating into the pre-fracture weakening microgroove. S5. Perform electroplating treatment.

7. The manufacturing method of the blanking type EMC5050 LED bracket according to claim 6, characterized in that: The selective roughening process in step S3 specifically involves: covering the pad area with a photosensitive protective film, exposing only the EMC-encapsulated area, and then immersing the masked strip in a chemical roughening solution for roughening treatment, so that the surface roughness Ra of the metal in the EMC-encapsulated area reaches 0.8 μm to 1.5 μm; after roughening, the protective film in the pad area is removed, and the metal surface in the pad area remains in its original smooth state, with a surface roughness Ra of less than 0.2 μm after subsequent electroplating.

8. The manufacturing method of the blanking type EMC5050 LED bracket according to claim 6, characterized in that: The chemical roughening solution is an acidic oxidation system, the roughening temperature is 30°C to 40°C, and the processing time is 30 seconds to 90 seconds.

9. The manufacturing method of the blanking type EMC5050 LED bracket according to claim 6, characterized in that: Following step S3, an online sampling inspection step is also included. The online sampling inspection includes a three-level system: Level 1, before injection molding, the solderability of the pads and the bottom morphology of each individual metal support unit are tested; Level 2, after die bonding, 3 to 5 units are removed from the strip every 500 units to test the die bonding position accuracy, silver paste coverage and chip cracks; Level 3, after wire bonding, 3 to 5 units are removed every 500 units to test the push-pull force and inspect the wire bonding morphology.

10. The manufacturing method of the blanking type EMC5050 LED bracket according to claim 6, characterized in that: The electroplating process in step S5 involves sequentially plating a barrier layer and a reflective layer. The barrier layer has a thickness of 1.5 μm to 2.0 μm, and the reflective layer has a thickness of 2.0 μm to 3.0 μm.

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