TWI241033B - Packaging structure of light emitting diode and its packaging method - Google Patents

Abstract

A packaging structure of light emitting diode and its packaging method is disclosed, wherein the lead frame, the metal base, and the plastic housing are bonded by embedded injection. The opening of the top of metal base and the plastic housing forms one reflection cup with high reflectivity to enable the light emitting diode bonded onto the metal base to irradiate the generated light toward large-angle range with low loss. Moreover, the design of lead frames can enable multiple chip packages and provide the effect of mixed-color or full-color light output.

Description

1241033 V. Description of the invention (1) [The invention belongs to the method of the present invention, especially the method with a plastic shell. [The previous technology has good convenience in heat dissipation during the process of emitting light. For the double material of the base material, please refer to the structure '. First, a metal top surface is punched into the body. 1 Q when combined, the shooting cup 16 exposes the anti-LI of the block 1 2 2. The technical field of L2 welding after plastic is related to a kind of continuous good material in the shape of the diode, which often requires a quality structure. Figure 1 uses the shooting block 12 2 to be out of shape, and is worn in the plastic shooting cup 1 6 1 4 Complete the body 10 into a package. This structure conducts to the outside world at a specific angle range. However, the package structure of the above-mentioned junction and light-emitting diodes and its packaging method, including the f-injection method, and the lead-frame, metal base n-reflectivity reflective cup packaging structure In the technical field of packaging and sealing, since the light-emitting chip generates t-heat, the light-emitting chip must be directly set on the shell (such as metal); however, plastic materials must be used for packaging. However, the plastic and the heat-dissipating part have defects in the bonding strength. 'In the conventional technology, a light-emitting diode (LED) is encapsulated to form a plastic body 10 that covers a lead frame 11 and then a perforation 17 under the plastic body 10; the metal block 1 2 is a concave reflection cup 16 When the metal block 12 and the plastic body pass through the perforation 17 of the plastic body 10 stepwise, and the top surface of the anti-body 10 is connected to the bottom of the gold cup 13; the light-emitting chip i 3 and the lead frame ii Behind the pins, the external circuit of the light-emitting chip 13 is formed; and a lens j 5 is connected to the top of the light-emitting chip 13 and the reflection cup 16 of the metal block 12 can be used to make the light source enter the enclosure; Block 12 can directly use the light-emitting chip 1 3 ′ for heat dissipation. The architecture has some drawbacks. It uses adhesive bonding

1241033 -------______ V. Description of the invention (2) '' ------ ^ The metal block 12 and the plastic body 10 are prone to h-shaped unevenness and voids, which may cause the metal block to fall off and displace, water The gas enters the packaging structure, causing the product to fail. In addition, the metal block 丨 2: The reflectivity of the inner wall surface of the cup U is not good. It is effective to reflect the light irradiated on the second and second sides of the light for high efficiency reflection and loss; secondly, the design of the straight wire U can only be used for a single chip Packaging, unable to make multi-chips' Packaging is early: the packaging structure cannot achieve mixed color or full-color light source output. ^ Figure 2 shows another conventional technology of a light-emitting diode sealing structure. The top surface of the substrate with high heat dissipation coefficient is covered with an insulating layer. The surface copper layer is provided on the insulating edge layer. 06, 07 And the surface copper layers 06 and 07 have surface = brush layer 05. First, drill a hole through the insulation layer 〇1, exposing the substrate ⑽; fix the wafer 〇2 on the substrate oo in the blind hole 08, and then connect the bonding wire 03 to the surface copper layer 06 〇7; Finally, apply grease 〇4 in the blind hole 以 to encapsulate the bonding wire 03 and the wafer 〇2 'This completes the package; the copper layers 06 and 〇7 exposed on the printed surface 05 are the product's Two electrodes. Although this structure does not have the problem of the bonding strength of the structure shown in Figure 1, because the ability of the inner wall surface of the blind hole 08 on the substrate 00 to reflect the lateral light of the wafer 02 is extremely poor, even if it is to be improved by plating, it is also because of its structural design. The problem is that it is not possible to locally plate only at the position of the blind hole 08; the low reflectance of the blind hole 08 reduces the body brightness. Therefore, the existing light-emitting diode packaging technology is not yet sufficient for thermal energy 1, structural strength and light wheel output efficiency; in fact, there is also considerable room for improvement in process reliability 1 product reliability. [Summary of the Invention] ^

1241033 V. Description of the invention (3) In view of the problems of the above-mentioned conventional technology, the present invention has a high-power, ancient four-pointer, H is a light-emitting diode packaging structure that provides complex τA efficiency, and a sealing method. The heat dissipation capability and light output efficiency of the H-theta-liter package structure are wider, and the multi-chip package achieves the effect of color mixing and full color. The vehicle can be used for construction, and the light-emitting diode package provided by Ming Dynasty is composed of a base, a lead frame, and a plastic case. Among them, the guide plus anti-guru + ^ — Lens Saki f, 丄, 、, and Izumi have several pins, each pin has a recording, Izumi &, extended some bonding wire area around, with, covered with metal crystal ring around the wire The upper part of the apple; m edge, the central area of the top surface of the plastic shell package Hi: There is an opening to expose the metal crystal base and the welding wire bar.::ΐ 丄 Reflection cup, and expose the outer ends of all pins and red lines &, And the light-emitting chip is combined with the gold: shell ϊ borrow: ϊγγ " in the reflective cup to connect the bonding wire area; the lens uses two plastics ❹α to protect the thin light-emitting chip and the bonding wire. Incidence 2; ΐ! Ming provides the following steps: First, bury the shot = cut out a plurality of forming ㈣㈣--a plurality of lead frame surface of the bracket: cook ^, the knife does not join the light-emitting chip in the metal base of the reflective cup After the top &, a plurality of bonding wires are used to electrically connect the light emitting chip and the ” and then each plastic crystal base is packaged. f. Spring, in addition, the present invention provides a light-emitting diode lead frame, bean spoon bow, each pin comprises an inner pin and an outer bow connected to each other, inner: dagger: and-light-emitting chip Electrical connection, it has-a bend: to make the stand 2 into a higher bending level at the end, and the outer pin is for connection with the external circuit / for the review board of the fishing bureau and people familiar with this skill , Can clear

Page 8

1241033 V. Description of the invention (4) To understand the technical means, features, and effects of the present invention, # 幺 歹 幺 歹 will give you examples with detailed illustrations as follows. Μ [Embodiment] Please refer to Figs. 3A-3D. The first preferred embodiment of the present invention is a household light-emitting diode package structure, which is composed of a plastic housing 20, a lead frame 21, 18, and a base 22. The light emitting chip 24 and the lens 38 are composed.卞 Metal The metal base 22 for heat dissipation is a disk-shaped object, in which Mai is an ancient ^ I ^ _ protruding platform 2 2 0, and the periphery has an outwardly extending extension 2 2 1. The lead frame 21 has four pins LI, L2, L3, and L4, respectively, and has independent bonding wire areas 210, 211, 212, and 213 surrounding the platform 220, as shown by the dashed line in the figure 3A. The detailed structure of the lead frame will be matched with the figure π in this example. In this example, the plastic housing 20 is made of PP material (Polyphthalamide, poly (acetic acid)) with a surface with a 90% reflectivity after molding. The injection technology enables the plastic housing 20 to be ejected "and the metal base 22, and covered with two springs above the platform 220 of the metal base 22" to form a ring-shaped reflective cup 23; ': Above the soil seat 22, and bonding the light-emitting chip 24 and the wire bonding area of the lead frame 21. 211 = 112, 213 can be connected by welding wire, and then the lens 38 can be used to complete the break-through. 『F 爹 体 体 2 0 peripheral edge to form a higher side wall 2 〇1, such as in the 3 B, 3 C :: = 201 is The lower joint part 202 can be used to form various types of lens junctions and lenses, which will be described in detail in Figures 4-7B. π, 3 <: Fig. 10, it can be seen that the metal base 22 is protruded with a white edge (extended in combination with the plastic casing 20's buried entrance design), making the two

^ 41033 Yu and Fa ΐ ⑸ ~ ^ " '~ 一 ----- t tightly combined to improve product reliability; and because there is no need for packaging process A = followed by metal base 2 2 (as shown in Figure 1) (Conventional technology), also improve the process, force and reduce process variability. ◦ Second, the light-emitting crystal will be heated on the metal base 22, and thermal energy will be directly transmitted through the metal base 22, as long as the bottom of the metal base 22 Then contact a heat-dissipating substrate, that is, a good thermal energy transmission and heat-dissipating effect is achieved in February. ^ Secondly, please refer to FIG. 3E. The light-emitting diode encapsulation lead frame 2 60 provided by the present invention is located on a bracket 26 before packaging, and the figure 2 frame 260 has four lead wires. Each of the pins 261 includes an inner bow U62 and an outer pin 263 connected to each other. Each outer pin 2 6 3 is generally rectangular for connection to the outside; each inner pin 26 2 is also generally in the shape of a strip, and a through hole 4 ′ is provided on the outer pin to increase the bonding strength after the plastic is injected. In particular, the inner pins have eight. 'Test the folding section 2 6 5 so that it forms a bending stage with a higher end; this requires = $ the base 22 emits a higher surface, which will relatively make the reflection cup 23 have a larger inter-ice degree'. The light mixing effect of the light-emitting chip can be improved. At Z, the bonding wire area of the inner pins 2 62 can be closer to the surface of the metal base 22 for # -line operation. In addition, the end edge of the inner pin 2 6 2 is concavely curved, and the concave arc-shaped edge at the end of the inner pin 2 6 2 is almost co-circular. 3 can have larger space for light emitting crystals. After Yuancheng plastic injection operation, the four inner pins 2 62 are partially exposed in the 1 field, respectively, and are used as bonding wire areas (such as bonding wire areas 210, 211, 212, and 213 in Figure A). ). 2.% mai read Figures 4-7B. After the wire bonding operation is completed, different packaging methods can be used according to different products.

1241033 i. Description of the invention (6) In the fourth figure, the semi-finished σ field weight completed by the welding wire is clicked into the resin 33 from the top and completely covered; the sealing method of Erjianyi is that the grease 33 is hardened, and the seal is completed. . ;; =, 25 structure, the laser material 34 to be used for tree color can be light output efficiency or mixed laser material 34 for packaging. ^ In resin 33, or directly in the pure = 5 picture, the semi-finished product completed by the welding wire can be spotted with internal glue ^, but only covers the light-emitting chip 24, the welding wire 25 and the wire ^ κ 〒, the welding wire area of Mizuki 21 After hardening, click on resin 3 3 on the outside to strengthen the inner rubber 35 or resin 33, or the light-emitting material 34 can be mixed with, or replaced by eight private allowances; especially the laser material 34 When it is within ¥ 35, it can provide good excitation uniformity. Feng: Whatever is not shown in the figure 'First, complete the encapsulation in Fig. 5 as the sealant. 33 First click into the groove 3 6 0 of the mold pellet 36 (Fig. 6A); For the semi-finished product, the mold particles are attached to the opening downward, and the package is completed after hardening and demolding, and a lens 38 necessary for light refraction is generated (Figure 6C). To = as shown in Figures 7A-7B, to complete the encapsulation operation of the internal rubber 35 and resin 3 in Figure 5 except that the resin 33 is not cured (Figure 7A), and the f ^ 7β lens 38 is bonded to the top 'Resin 33 is hardened and adhered to complete the package (Figure 7B). Refer to Figures 8A-8C for details. Regardless of the final package form, the present invention uses the top surface of the Dongzao a + Mongolia platform and the opening of the plastic casing to form a 1 ^ cup 23 = leaf. Good light output. The light-emitting chip 2 4 is prepared. In addition to light that directly penetrates the lens or resin, the side light and the light reflected back to the reflection cup by the driver ’s tilt are based on the high

Page 11 1241033 V. Description of the invention (7) Reflective plastic case This can reduce the light output and form a point light source. In addition, please refer to the lead frame 21 and the large-area, multi-weld hair extension base 2. 2 buried incident or multi-chip, without removing the 2 1 design, can be used for multiple drawings) can also refer to the 10A package structure at the same time, the present invention lies in the multiple guides of the metal base and the "bracket" The structure includes the following steps (such as injection molding of a plurality of plastics 41), and each plastic shell cup exposes a line area on the metal base; then, separate faces (step 4 2): Ran line area (Step 43); 4 4) ° and the loss of the platform of the metal crystal base, and maintain the "": Han shot out "as the title. Large light diffusion angle, not shown in Figure 9A-9B, right ..., the platform belongs to Its ^ 〇 丨 feet and four bonding wire area on the chip 22, can be used to package a single large chip, or to provide a polycrystalline χ out design, even if the i-suit is sealed. Due to the gold drop displacement question ί ::: :: Integrated light-emitting chip light-emitting chip bonding wire connection, ^: of the lead frame package structure Light-connected color chip (㈣ provides-a kind of packaging method of light-emitting diode and diode 4 Satoshi, which is in a plastic shell, which is combined by buried injection; '= on (, picture), and this bracket as The main light-emitting diode packaging operation. The packaging method of the light-emitting diode provided by the Ming, mainly shown in Figure 1): First & Cover the metal with and open it to form a reflective top surface, and expose the multiple soldered light-emitting chips of each lead frame to the top of the metal base in the reflection cup, and then electrically connect the light-emitting chips with several bonding wires. And soldering last 'then encapsulate each plastic crystal holder (step

Page 1212410 V. Description of the invention (8) Of course, it can also include in practice—the steps of punching and separating the packaged lead frame I cutting the bracket, as shown in the figure, with various different sealing steps. It can be covered with-inner rubber to cover the reflective cup as in Section 4_7B. For example, after the encapsulation step can be more encapsulated, the following steps can be performed in the zinc wire area to complete the inner rubber one mold pellet, and a resin P material is injected into the groove. (1) Provide a plastic case with a groove, which fits down to the concave part of the mold pellet. 2)% After the encapsulated plastic material has hardened, release the plastic case. And (3) the resin material is defined to limit the present invention. ‘It ’s not after use that it is modified to replace the old, and those who are skilled in this art create it through the disclosure of this invention. 3. All of them are derivative changes based on the technical idea of the present invention: embossed on ;: the equality made within the scope of the technical idea of the present invention. ”White should be included in the scope of patent application of the present invention. Page 13 1241033 Scheme Brief description of FIG. 1 is a light emitting diode package structure of the prior art; FIG. 2 is another light emitting diode of the prior art; FIG. 3B is a cross-sectional sound diagram taken along the line AA of FIG. 3A. FIG. 3C A cross-sectional view g along the line B-B in FIG. 3A; 'Figure 3D is a schematic bottom view of the first preferred embodiment of the present invention; Figure 3E is a schematic view of the lead frame structure of the first preferred embodiment of the present invention A schematic cross-sectional view of the second preferred embodiment of the present invention; FIG. 2i A schematic cross-sectional view of the third preferred embodiment of the present invention; FIG. 6A-6C are schematic diagrams of the sealing process of the fourth preferred embodiment of the present invention. 7A-7B is a schematic diagram of the packaging process of the fifth preferred embodiment of the present invention =) -8C is a schematic diagram of the light scattering and thermal energy transmission of the present invention; "9A-9B are the sixth preferred embodiment of the present invention The package structure is not intended;

1 10 A-1 0 B are the n-Qin A sounds and pictures of the present invention; and the package flow chart of the preferred embodiment of the T umbrella heart VII. The 11 is the umbrella for the present invention. ^ Mj π The main flow chart of the first polar package method. [Illustration of Symbols]

Pins LI, L2, u, U substrate 0 0

Page 14 1241033

Page 15 1241033 Brief description of drawings Welding wire 2 5 Bracket 26 Lead frame 260 Pin 261 Inner pin 262 Outer pin 263 Through hole 2 6 4 Bend 265 Resin 3 3

Laser material 34 Inner rubber 3 5 Mould pellets 3 6 Groove 3 6 0 Lens 38 Step 4 1 Shoot out a plurality of plastic casings by burying and inserting on a plurality of lead frames of a bracket

Step 4 2 Join the light emitting chip to the top surface of the metal base in the reflective cup. Step 4 3 Connect the light emitting chip and the wire bonding area electrically with several bonding wires. Step 4 4 Package each plastic crystal holder.

Page 16

Claims (1)

1241033 6. Scope of patent application 1. A light emitting diode package structure comprising: a metal base; a lead frame with a plurality of pins, each of which has a wire bonding area, and the wire bonding areas are arranged in a circle At the top edge of the metal base; a plastic shell covering the periphery of the metal crystal base and the lead frame, which has an opening to expose the central area of the top surface of the metal crystal base to form a reflective cup and expose the The outer ends of the leads and the bonding wire areas; at least one light emitting chip combined with the top surface of the metal base in the reflection cup, and electrically connecting the bonding wire areas through a plurality of bonding wires; and a lens, package The plastic case. 2. The light-emitting diode packaging structure according to item 1 of the scope of the patent application, wherein the top surface of the metal base has a platform in the reflective cup, and the light-emitting chip is located on the platform. 3. The light-emitting diode packaging structure according to item 1 of the scope of the patent application, wherein the metal base has an extension protruding from the periphery. 4. The light emitting diode package structure described in item 1 of the scope of patent application, wherein each of the pins has an inner pin and an outer pin connected, and each inner pin has a bent portion to form The higher bending level at the end, and the aforementioned bonding wire area is located on the inner pins, and the outer pins are for connection with external circuits. 5. The light emitting diode package structure as described in item 4 of the scope of the patent application, wherein the end edges of the inner pin ends are concave arc-shaped, and the concave arc-shaped end edges of all the inner pin ends are co-circular. 6. The light emitting diode package structure as described in the first patent application scope, wherein 1241033 The number of pins of the lead frame and the bonding area is four. 7. The light emitting diode packaging structure according to item 丨 in the scope of the patent application, wherein the periphery of the plastic casing has a higher side wall. 8. The light-emitting diode packaging structure according to item 7 of the scope of the patent application, wherein the inside wall of the 50H has a joint lower than the height of the side wall. 9. The light emitting diode packaging structure according to item 丨 of the patent application scope, wherein the plastic case is made of PPA material (Polyphthala ^ de). 10 · The light emitting diode packaging structure according to item 1 of the scope of patent application, wherein the lens is formed of a laser material. Π The light emitting diode package structure as described in item 丨 of the patent application range, wherein the lens is formed of a resin containing a laser material. 12. The light-emitting diode packaging structure according to item 1 of the scope of patent application, further comprising an inner rubber covering the reflection cup and the bonding wire areas. 13. The light-emitting diode packaging structure according to item 12 of the scope of the patent application, wherein the inner glue contains a laser material. 1 4 · The light-emitting diode packaging structure described in item # 2 of the application # patent scope, in which the inner rubber is a laser material. 〃 1 5 · — A light emitting diode packaging method, including the following steps: a plurality of plastic cases are injection-molded on a plurality of lead frames of a bracket in a buried injection manner, and each of the plastic cases is respectively covered with a metal base, And forming a reflection cup on the exposed top surface of the metal base, and exposing a plurality of bonding wire areas of each of the lead frames; the knife is engaged with the gold of at least one light emitting chip in each reflection cup 1241033 丨 · 丨 · 6. The scope of patent application belongs to the top surface of the base with a plurality of wire bonding electric pots; and each of the light-emitting chips and the bonding wires are used to package the plastic crystal base. 16. As described in the scope of the patent application, the white-light-emitting diode sealing party, the earth-cube package 3-stamping and cutting should be carried out, and these lead frames are installed. ", To separate the luminescence described in the completed patent application No. 15 of the patent application, the top surface of the metal base has-platforms located on each; f, and each of the light emitting chips is bonded to each of the platforms." In the reflection cup, 18. The peripheral edge of each of the metal bases in the light-emitting diode described in item 15 of the patent scope projects an extension. ， 去 ， 19. As described in the scope of the patent application No. 15 of the light-emitting diode body of the plastic casing injection molding one of the higher one ^ /, 20. According to the scope of the patent-application patent No. 15 Each of the lead frames in the body seal has a plurality of pins, each of the pins has an inner pin and an outer pin, and each of the inner pins has a bend ^ connected to form a higher end fold Bend level, and the aforementioned bonding wire area is located on the inner pins of j, and these outer pins are for connection with external circuits. ;. Hai et al. 2 1 · As described in Item 20 of the scope of the patent application, the light emitting diode sealing skirt is in the shape of a concave arc at the end of the inner pin, and all the concave arc ends of the inner lead are at the end. Round. Feet 2 2 · According to the light-emitting diode packaging method described in item 15 of the scope of patent application, the packaging step is to cover the rugged plastics with a resin material. Page 19 1241033 6. Application scope. 2 3 · The light emitting diode packaging method according to item 22 of the scope of patent application, wherein the resin material contains a laser material. 2 4. The method of packaging light emitting diodes as described in item 15 of the scope of patent application, wherein the packaging step is to cover the plastic cases with a laser material. 25. The light emitting diode packaging method as described in item 15 of the scope of the patent application, wherein the packaging step includes a step of covering the reflective cups and the fresh line areas with an inner glue. 26. The light-emitting diode packaging method according to item 25 of the scope of patent application, further comprising the step of covering the inner rubber with a resin material. 2 7. The light-emitting diode packaging method as described in item 26 of the scope of patent application, which further includes the step of bonding a resin material to the resin material with a lens. 2 8. The light-emitting diode packaging method according to item 25 of the scope of patent application, further comprising the following steps: providing a mold pellet having a groove, the groove is filled with a resin material; and the inner rubber is encapsulated The plastic shells are attached downward in the grooves of the mold pellets; and after the resin material has hardened, the plastic shells are demolded. 2 9. —A lead frame for a light emitting diode, comprising a plurality of pins, each of which includes an inner pin and an outer pin connected, wherein each of the inner pins is used to electrically connect a light emitting chip. Connection, and it has a bent portion, so that it forms a bending stage with a higher end, and the outer pin is for external use Page 20 1241033 6. Scope of patent application Circuit connection. 30. The lead frame of the light-emitting diode as described in item 29 of the scope of the patent application, wherein the ends of the inner pin ends are concavely arc-shaped, and all the ends of the inner pin ends are concavely arc-shaped. Round. 3 1. The leadframe of the light-emitting diode as described in item 29 of the patent application scope, wherein the number of the pins is four. 3 2. The lead frame of the light-emitting diode according to item 29 of the patent application scope, wherein the inner pin has a through hole.