Packaging mode of fused convex lens SMD (Surface Mounted Device) product

Abstract

The invention discloses a packaging mode of a fused convex mirror SMD (Surface Mounted Device) product, which comprises the following steps of: welding and fixing an LED (Light Emitting Diode) chip on a bonding pad base, welding a hardware bending piece below the bonding pad base, forming a plurality of mold locking holes in the hardware bending piece, coating the bonding pad base with inner glue through an injection molding process, and performing injection molding on outer glue below the inner glue to obtain an LED bracket, epoxy resin glue is encapsulated in each bonding pad base cavity through a dispensing process, epoxy resin is respectively molded on the epoxy resin glue and around the LED support, a convex mirror is formed on the epoxy resin glue, and packaging of the fusion type LED packaging structure is completed; the white glue and the black glue are coated on the bonding pad base, the contrast ratio is improved, the epoxy resin glue added with the colored glue is filled in the cavity of the bonding pad base, the brightness of the LED lamp is improved, the mold locking hole is formed in the hardware bending piece, the connection strength of the black glue and the hardware bending piece is improved, and the service life of the LED lamp is prolonged.

Description

Technical Field

[0001] The invention belongs to the field of LED packaging, and in particular relates to a packaging method of a fusion-type convex mirror SMD product. Background Art

[0002] At present, the LED lamp beads used in the display industry mainly have two packaging forms: direct plug-in type (LAMP) and surface mount type (SMD). LAMP is a monochrome lamp, and the base color of the display screen is three colors. Outdoor direct plug-in LAMP LED has the advantages of high brightness, high reliability, and low failure rate, but it also has disadvantages such as high price, slow heat dissipation, low production efficiency, high maintenance and replacement costs, and thick screen body. Due to the height and large size of the lamp beads, the module is thick and the spacing is large; the current direct plug-in lamp beads are only suitable for screens above P12, resulting in a thick and heavy screen body, which is not easy to install and maintain. Overheating may occur in high temperature environments, affecting the stability and life of the lamp. Compared with traditional lamps, the price of direct plug-in LED headlights is relatively high, which increases the initial investment cost. Abandoned LED lamps may pollute the environment.

[0003] The SMD lamp beads of the patch package adopt a bowl-cup method to solidify three colors. The original three lamps form a group, but one lamp emits three colors, which greatly reduces the packaging cost and improves efficiency. The thickness of the SMD lamp beads is only 1-2.5mm, which is about 3 times shorter than the direct plug-in. It can reduce the thickness of the module, reduce the weight of the template, facilitate installation and replacement, and be safer to use. However, the outdoor LED display has very high requirements on brightness, and while maintaining high brightness, it also needs to have good sealing and service life, and it is easy to disassemble and install, and easy to maintain.

[0004] Patent CN104752595A discloses a packaging method for a flip-chip LED chip and a flip-chip LED chip using the packaging method, wherein solder paste is arranged on a substrate, and the electrodes of the LED chip are soldered to the substrate after reflow soldering, and a thin film is melted by heat during the reflow soldering process and covers the LED chip, and then cooled and solidified to form a packaging layer; however, the packaging layer in this scheme is easily oxidized and falls off under long-term exposure to ultraviolet light outdoors, resulting in poor sealing, short service life, and low brightness, and is not suitable for outdoor use.

[0005] Patent CN112635447A discloses an LED packaging structure and manufacturing method, which increases the brightness of the LED lamp packaged with black glue by laying a transparent glue layer on a substrate and covering the LED chip, setting a white glue layer outside the transparent glue layer, and setting a black glue layer outside the white glue layer; however, internal stress will be generated between different glue layers in this scheme, and layer cracking will easily occur after long-term outdoor ultraviolet irradiation, causing the LED lamp to lose its sealing, easily get water in and cause damage, have a short service life, and be inconvenient to repair and replace. Summary of the invention

[0006] The purpose of the present invention is to provide a packaging method for a fused convex mirror SMD product to solve the problem of how to maintain high brightness while having good sealing and service life and easy disassembly and installation.

[0007] The present invention combines the advantages of both direct-insert and surface-mount LED packaging forms, improves contrast by coating the pad base with white glue and black glue, improves brightness of the LED lamp by filling epoxy resin glue with colored glue in the cavity of the pad base, and opens a locking hole on the metal bending part, the locking hole has an elliptical structure with a size of 0.3*0.2mm, thereby improving the connection strength between the black glue and the metal bending part, and improving the service life of the LED lamp. At the same time, it is easy to replace with lower cost.

[0008] The purpose of the present invention can be achieved through the following technical solutions:

[0009] A packaging method for a fused convex mirror SMD product includes the following steps:

[0010] Step 1: Solder and fix the LED chip on the pad base to complete the LED chip's die bonding process.

[0011] Step 2: Weld the bent metal parts under the pad base. A plurality of locking holes are evenly opened on the bent metal parts. The pad base is covered with inner glue through the injection molding process. The outer glue is injection molded under the inner glue to obtain the LED bracket.

[0012] Step 3. Fill the cavity of each pad base with epoxy resin glue through the glue dispensing process to wrap the LED chip with epoxy resin glue. After the glue dispensing is completed, use the double-channel molding process to mold the epoxy resin on the epoxy resin glue and around the LED bracket respectively, forming a convex mirror on the epoxy resin glue, and forming an epoxy resin coating around the LED bracket. Bend the pin part of the hardware bending part so that the bottom of the pin is 0.05-0.1mm higher than the bottom of the outer glue, and there is a 0.05mm gap between the inner side of the pin and the outer glue to complete the packaging of the fusion LED packaging structure.

[0013] In step 1, the number of LED chips is N+1, where N is a natural number.

[0014] In step 2, the color of the inner glue is one of white, gray and cyan, and the color of the outer glue is black.

[0015] Furthermore, the die bonding wire process in step 1 is a face-up process or a flip-down process.

[0016] Furthermore, the steps of the formal process are:

[0017] Use primer to fix the LED chip on the pad base, use wire bonding to connect the current, and connect the gold wire in series between the positive and negative poles of the LED chip and the copper foil. When welding the gold wire, another gold wire is welded between the gold wire welding point on the copper foil and the copper foil to form a double wire to obtain a solid crystal pad.

[0018] Furthermore, in the method of welding the gold wire, the arc of the gold wire is stretched before approaching the wire bonding point, parallel to the copper foil, to form a "zero wire arc".

[0019] Furthermore, the steps of the flip chip process are:

[0020] The electrodes of the LED chip are directly combined with the pad base through flip-chip welding technology to obtain a die-bonding pad.

[0021] Furthermore, in step 2, the position where the mold locking hole is opened is the contact point between the metal bending part and the outer rubber.

[0022] Furthermore, the material of the inner and outer glue in step 2 is one of PPA resin, EMC and epoxy resin glue.

[0023] Furthermore, the materials of the inner rubber and the outer rubber are both PPA resin.

[0024] Furthermore, in step three, different colored glues are added to the epoxy resin glue according to the display colors of the LED chips to form epoxy resin glues of different colors.

[0025] Furthermore, blue-grey epoxy resin glue is poured into the cavity of the solder pad base of the red LED chip.

[0026] Furthermore, in step three, the shape of the convex mirror is hemispherical, elliptical or other special shapes.

[0027] Beneficial effects of the present invention:

[0028] The packaging method of the present invention combines the advantages of both direct-insert and surface-mount LED packaging methods, which not only improves the brightness and durability of the LED, but also facilitates replacement at a lower cost; by combining multiple LED chips, the display effect of the color combination is enriched, and the efficiency of maintenance and replacement is improved; by coating the pad base with inner glue, the inner glue is set to different colors according to the contrast and brightness requirements, thereby improving the brightness and contrast of the LED chip to different degrees; a double-wire process is used when the LED chip is wired to connect, thereby avoiding the phenomenon of dead lights after desoldering; by forming a "zero-line arc" when the gold wire is welded, the internal stress and external extrusion force are buffered, and the compressive strength of the LED lamp is improved; by opening a locking mold hole on the hardware bending part, the connection strength between the hardware bending part and the LED bracket is improved; by using the same resin, the fusion of the inner glue and the outer glue is improved, and it is not easy to produce layer cracking, thereby improving the durability and service life of the LED. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below in conjunction with the accompanying drawings.

[0030] Figure 1 It is a schematic diagram of the LED packaging structure obtained by the present invention;

[0031] Figure 2 It is a schematic diagram of the structure of hardware bending parts;

[0032] Figure 3 It is a cross-sectional view of an LED bracket formed by injection molding of inner and outer rubber;

[0033] Figure 4 Schematic diagram of the structure of the die-bonding pad, inner glue and outer glue in the present invention, where A is a double-line structure;

[0034] Figure 5 This is a schematic diagram of the LED chip welding structure of the present invention, where point B is the "zero line arc".

[0035] In the figure: 1. Hardware bending parts; 101. Pins; 102. Locking holes; 2. LED bracket; 3. Inner glue; 4. Outer glue. DETAILED DESCRIPTION

[0036] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Example 1

[0038] A packaging method for a fusion type LED packaging structure comprises the following steps:

[0039] Step 1: Use the normal mounting process to fix the red, green and blue LED chips on the pad base with primer and connect the current with wires. Figure 5 As shown, connect the gold wire in series between the positive and negative electrodes of the LED chip and the copper foil. When welding the gold wire, stretch the arc of the gold wire before approaching the wire-bonding point, parallel to the copper foil, to form a "zero line arc". Please refer to Figure 4 As shown, another gold wire is welded between the gold wire welding point on the copper foil and the copper foil to form a double wire, completing the die bonding wire process of the LED chip to obtain a die bonding pad.

[0040] By welding another gold wire between the gold wire welding point on the copper foil and the copper foil to form a double-wire structure, the phenomenon of dead light after the LED chip and the copper foil welding point are detached can be avoided, the service life of the LED lamp can be increased, and the internal stress and external extrusion force can be buffered by forming a "zero line arc", thereby improving the compressive strength of the LED lamp.

[0041] Step 2: Weld the bent metal parts under the pad base to get the metal terminals. Figure 3-4 As shown, the pad base is covered with white PPA resin through injection molding, and black PPA resin is injected under the white PPA resin to form a bracket. Three locking holes are opened where the metal bending part contacts the black PPA resin. For the structure of the locking holes, please refer to Figure 2 As shown, the size of the locking hole is an elliptical structure of 0.3*0.2 mm, and an LED bracket is obtained.

[0042] By coating the pad base with inner glue and setting the inner glue to different colors according to the contrast and brightness requirements, the brightness of the LED chip can be improved to different degrees. By filling the outer glue outside the inner glue, the contrast is improved, and the problem of uneven color when brushing ink on the surface of the white LED bracket in the traditional process is solved. By using the same resin, the fusion of the inner glue and the outer glue is improved, and the problem of layer cracking after oxidation is solved. At the same time, good air tightness, high waterproof performance and long service life are guaranteed. The locking hole size is an elliptical structure of 0.3*0.2mm. If the locking hole is too large, the metal is easy to break when bending, and if it is too small, the glue cannot be locked. Under the size structure of the present invention, the bonding strength between the hardware bending parts and the glue can be improved.

[0043] Step 3: Fill the three pad base cavities with epoxy resin glue through the glue dispensing process to wrap the LED chip with epoxy resin glue. Different color glue is added to the epoxy resin glue according to the color of the LED chip. Fill the blue-gray epoxy resin glue in the pad base cavity of the red LED chip. After the glue dispensing is completed, use the double-channel molding process to mold the epoxy resin on the epoxy resin glue and around the LED bracket respectively to form a convex mirror on the epoxy resin glue. The convex mirror is oval and forms an epoxy resin coating around the LED bracket. Please refer to Figure 1 As shown, the pin part of the metal bending part is bent so that the bottom of the pin is 0.07mm higher than the bottom of the outer glue, and there is a 0.05mm gap between the inner side of the pin and the outer glue, completing the packaging of the fusion type LED packaging structure to obtain a fusion type LED packaging structure.

[0044] Epoxy resin glue is poured into the cavity of the pad base. The epoxy resin glue has a good reflective effect, improves the brightness and refractive index, and different color glues are added to the epoxy resin glue according to the different colors of LED chips. The complementarity of colors is used to improve the brightness and contrast, and improve the display effect of the LED display under strong light. A convex mirror is molded on the epoxy resin glue using a dual-channel molding process. The convex mirror can focus light, thereby increasing the brightness of the LED chip. Epoxy resin is coated around the LED bracket to protect the LED bracket and improve the mechanical strength and service life of the LED packaging structure. The setting of the pins can allow the tin to be more fully integrated and penetrated more completely during soldering, forming a wrapping effect, making the soldering more firm and reliable. The bottom of the pin is higher than the bottom of the outer glue, which can make the product board smoother after soldering.

[0045] Example 2

[0046] Step 1: Use the positive assembly process to fix the red LED chip on the pad base with primer, use wire bonding to connect the current, and connect the gold wire in series between the positive and negative electrodes of the red LED chip and the copper foil. When welding the gold wire, stretch the gold wire arc before approaching the wire bonding point, parallel to the copper foil, to form a "zero line arc", and weld another gold wire between the gold wire welding point on the copper foil and the copper foil to form a double wire, completing the LED chip's die bonding wire process to obtain a die bonding pad.

[0047] Step 2: Weld the bent metal parts under the pad base to obtain the hardware terminal, cover the pad base with gray EMC through injection molding, and inject black EMC under the gray EMC to form a bracket. A locking hole is evenly opened at the place where the bent metal parts contact the black EMC to obtain the LED bracket.

[0048] Step three, fill the epoxy resin glue in the pad base cavity through the glue dispensing process, so that the epoxy resin glue wraps the LED chip, and fill the blue-gray epoxy resin glue in the pad base cavity of the red LED chip. After the glue dispensing is completed, use a double-channel molding process to mold the epoxy resin on the epoxy resin glue and around the LED bracket respectively, and form a convex mirror on the epoxy resin glue. The convex mirror is semicircular, and an epoxy resin coating is formed around the LED bracket. Bend the pin part of the hardware bending part so that the bottom of the pin is 0.05mm higher than the bottom of the outer glue, and there is a 0.05mm gap between the inner side of the pin and the outer glue. The packaging of the fusion LED packaging structure is completed to obtain a fusion LED packaging structure.

[0049] Example 3

[0050] Step 1: Use the positive mounting process to fix 3 LED chips on the pad base with primer. The LED chips are red, green and blue. Use wire bonding to connect the current. Connect the gold wire in series between the positive and negative electrodes of the LED chip and the copper foil. When welding the gold wire, stretch the gold wire arc before approaching the wire bonding point and make it parallel to the copper foil to form a "zero line arc". Then weld another gold wire between the gold wire welding point on the copper foil and the copper foil to form a double wire. The LED chip's solid crystal wire bonding process is completed to obtain a solid crystal pad.

[0051] Step 2: Weld the bent metal parts under the pad base to obtain the hardware terminal, cover the pad base with cyan epoxy resin glue through the injection molding process, and inject black epoxy resin glue under the cyan epoxy resin glue to form a bracket. Five locking holes are evenly opened at the place where the bent metal parts contact the black epoxy resin to obtain the LED bracket.

[0052] Step three, fill the epoxy resin glue in each pad base cavity through the glue dispensing process, so that the epoxy resin glue wraps the LED chip, add different color glues to the epoxy resin glue according to the color of the LED chip, fill the blue-gray epoxy resin glue in the pad base cavity of the red LED chip, and after the glue dispensing is completed, use a double-channel molding process to mold the epoxy resin on the epoxy resin glue and around the LED bracket respectively, and form a convex mirror on the epoxy resin glue. The convex mirror is semicircular, and an epoxy resin coating is formed around the LED bracket. Bend the pin part of the hardware bending part so that the bottom of the pin is 0.1mm higher than the bottom of the outer glue, and there is a gap of 0.05mm between the inner side of the pin and the outer glue. The packaging of the fusion type LED packaging structure is completed to obtain a fusion LED packaging structure.

[0053] Example 4

[0054] Step 1: Use the flip-chip process to directly combine the electrode of a red LED chip with the pad base through flip-chip welding technology to complete the LED chip's die-bonding wire process and obtain a die-bonding pad.

[0055] Step 2: Weld the bent metal parts under the pad base to obtain the hardware terminal, cover the pad base with white PPA resin through injection molding, and inject black PPA resin under the white PPA resin to form a bracket. A locking hole is opened at the place where the bent metal parts contact the black PPA resin to obtain the LED bracket.

[0056] Step three, fill the epoxy resin glue in the pad base cavity through the glue dispensing process, so that the epoxy resin glue wraps the LED chip, and fill the blue-gray epoxy resin glue in the pad base cavity of the red LED chip. After the glue dispensing is completed, use a double-channel molding process to mold the epoxy resin on the epoxy resin glue and around the LED bracket respectively, and form a convex mirror on the epoxy resin glue. The convex mirror is semicircular, and an epoxy resin coating is formed around the LED bracket. Bend the pin part of the hardware bending part so that the bottom of the pin is 0.05mm higher than the bottom of the outer glue, and there is a 0.05mm gap between the inner side of the pin and the outer glue. The packaging of the fusion LED packaging structure is completed to obtain a fusion LED packaging structure.

[0057] Example 5

[0058] Step 1: Use the flip-chip process to directly combine the electrodes of the red, green and blue LED chips with the pad base through flip-chip welding technology to complete the LED chip bonding wire process and obtain a bonding pad.

[0059] Step 2: Weld the bent metal parts under the pad base to obtain the hardware terminal, cover the pad base with gray EMC through injection molding, and inject black EMC under the gray EMC resin to form a bracket. Three locking holes are opened where the bent metal parts contact the black EMC to obtain the LED bracket.

[0060] Step three, fill the three pad base cavities with epoxy resin glue through the glue dispensing process, so that the epoxy resin glue wraps the LED chip. Different color glues are added to the epoxy resin glue according to the color of the LED chip. Fill the blue-gray epoxy resin glue in the pad base cavity of the red LED chip. After the glue dispensing is completed, use a double-channel molding process to mold the epoxy resin on the epoxy resin glue and around the LED bracket respectively, and form a convex mirror on the epoxy resin glue. The convex mirror is elliptical, and an epoxy resin coating is formed around the LED bracket. Bend the pin part of the hardware bending part so that the bottom of the pin is 0.07mm higher than the bottom of the outer glue, and there is a gap of 0.05mm between the inner side of the pin and the outer glue. The packaging of the fusion LED packaging structure is completed to obtain a fusion LED packaging structure.

[0061] Example 6

[0062] Step 1: Use the flip-chip process to directly combine the electrodes of the three LED chips with the pad base through flip-chip welding technology. The LED chips are red, green, and blue. Complete the LED chip bonding wire process to obtain a bonding pad.

[0063] Step 2: Weld the bent metal parts under the pad base to obtain the hardware terminal, cover the pad base with cyan epoxy resin glue through the injection molding process, and inject black epoxy resin glue under the cyan epoxy resin glue to form a bracket. Five locking holes are opened where the bent metal parts contact the black epoxy resin glue to obtain the LED bracket.

[0064] Step three, fill the epoxy resin glue in each pad base cavity through the glue dispensing process, so that the epoxy resin glue wraps the LED chip, add different color glues to the epoxy resin glue according to the color of the LED chip, fill the blue-gray epoxy resin glue in the pad base cavity of the red LED chip, and after the glue dispensing is completed, use a double-channel molding process to mold the epoxy resin on the epoxy resin glue and around the LED bracket respectively, and form a convex mirror on the epoxy resin glue. The convex mirror is elliptical, and an epoxy resin coating is formed around the LED bracket. Bend the pin part of the hardware bending part so that the bottom of the pin is 0.1mm higher than the bottom of the outer glue, and there is a gap of 0.05mm between the inner side of the pin and the outer glue. The packaging of the fusion type LED packaging structure is completed to obtain a fusion LED packaging structure.

[0065] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0066] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A packaging method for a fused convex mirror SMD product, characterized in that: The following steps are involved: Step 1: Fix the LED chip on the pad base by using a die bonding wire process; Step 2: Weld the metal bending part under the pad base, evenly open a plurality of locking holes on the metal bending part, cover the pad base with the inner glue by injection molding, and inject the outer glue under the inner glue to obtain the LED bracket; Step 3: Fill epoxy resin glue into each pad base cavity, and then use a double-channel molding process to mold epoxy resin on the epoxy resin glue and around the LED bracket respectively, forming a convex mirror on the epoxy resin glue to complete the packaging of the fusion LED packaging structure.

2. The packaging method of a fusion type convex mirror SMD product according to claim 1 is characterized in that: The number of LED chips in step 1 is N+1, where N is a natural number.

3. The packaging method of a fusion type convex mirror SMD product according to claim 1 is characterized in that: The die bonding wire process described in step 1 is a positive assembly process, including the following steps: Use primer to fix the LED chip on the pad base, use wire bonding to connect the current, and connect the gold wire in series between the positive and negative poles of the LED chip and the copper foil. When welding the gold wire, another gold wire is welded between the gold wire welding point on the copper foil and the copper foil to form a double wire to obtain a solid crystal pad.

4. The packaging method of a fusion type convex mirror SMD product according to claim 1 is characterized in that: The die bonding wire process described in step 1 is a flip-chip process, comprising the following steps: The electrodes of the LED chip are directly combined with the pad base through flip-chip welding technology to obtain a die-bonding pad.

5. The packaging method of a fusion type convex mirror SMD product according to claim 3 is characterized in that: In the method for welding the gold wire, the arc of the gold wire is stretched before approaching the wire bonding point, parallel to the copper foil, to form a "zero wire arc".

6. The packaging method of a fusion type convex mirror SMD product according to claim 1 is characterized in that: The bottom of the pin of the metal bending part described in step 2 is 0.05-0.1mm higher than the bottom of the outer rubber, and there is a gap of 0.05mm between the inner side of the pin and the outer rubber.

7. The packaging method of a fusion type convex mirror SMD product according to claim 1 is characterized in that: The position of the locking hole in step 2 is the contact point between the metal bending part and the outer rubber, and the size of the locking hole is an elliptical structure of 0.3*0.2mm.

8. The packaging method of a fusion type convex mirror SMD product according to claim 1, characterized in that: The color of the inner glue in step 2 is one of white, gray and cyan, the color of the outer glue is black, and the materials of the inner glue and the outer glue are one of PPA, EMC and epoxy resin glue.

9. The packaging method of a fusion type convex mirror SMD product according to claim 1, characterized in that: In step 3, different colored glues are added to the epoxy resin glue according to the display colors of the LED chips to form epoxy resin glues of different colors, and the blue-gray epoxy resin glue is poured into the pad base cavity of the red LED chip.

10. The packaging method of a fusion type convex mirror SMD product according to claim 1, characterized in that: The shape of the convex mirror in step three is hemispherical or elliptical.

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