CN101226975A - High-power light-emitting diode chip packaging structure and manufacturing method - Google Patents

Abstract

The invention discloses a packaging structure of a high-power light-emitting diode chip and a manufacturing method thereof. The packaging structure is mainly characterized by comprising a base which is formed by integrally molding a metal material and an insulating material. The metal materials respectively form a heat dissipation seat which is respectively penetrated out from the upper surface of the base and the lower surface or the side surface of the base; and a plurality of electrodes positioned at appropriate positions around the heat sink and respectively projected from the upper surface of the base and the lower surface or side surface of the base. The insulating material is positioned between the heat dissipation seat and the electrodes, so that the heat dissipation seat is insulated and bonded with any one of the electrodes and any two of the electrodes. The light emitting diode chip is adhered to the upper surface of the heat sink, the positive and negative electrodes of the light emitting diode chip are respectively connected to the upper surface electrode of the base through the wires, and the external power supply supplies current to the chip through the lower surface electrode of the base, the upper surface electrode of the base and the wires to enable the chip to emit light.

Description

High-power light-emitting diode chip packaging structure and manufacturing method

technical field

The invention relates to a light-emitting diode, in particular to a package structure of a high-power light-emitting diode chip and a manufacturing method thereof.

Background technique

High Power LEDs are a part of the rapid development of the semiconductor industry in recent years. Regarding the packaging of high-power LED chips, the most important consideration is how to properly handle the high temperature and high heat generated by the high-power LED chips, so as to avoid affecting their performance and lifespan.

Fig. 1a shows a side view of a conventional LED chip packaging structure. As shown in FIG. 1a, a light emitting diode chip (Chip or Die) 16 is disposed on a substrate 19 made of BT resin (Bismaleimide Triazine Resin). The electrodes of the diode chip 16 are connected to the pre-set copper foil 15 on the substrate 19 to provide electrical connection to the outside through wires (Bonding Wire) 13 . A reflector 14 is arranged around the diode chip 16 , and finally the diode chip 16 and the wire 13 are sealed with resin 17 . The advantage of this packaging method is that it is suitable for packaging a large number of light-emitting diode chips in production, so the production cost is low. But its disadvantage is that resin is not a good heat-conducting material, so the high heat generated by the chip 16 mainly depends on the thin copper foil 15 to dissipate. This kind of packaging method that integrates the electrical channel and the heat dissipation channel is not suitable for high-power LED chips. .

US Patent No. 6,274,924 proposes a packaging structure for high-power light-emitting diode chips in which electrical channels and heat dissipation channels are separated. For convenience of explanation, the representative figure of US Patent No. 6,274,924 is referred to as FIG. 1b of this specification. As shown in FIG. 1 b , this structure mainly seals a metal lead frame (LeadFrame) 12 in a colloid made of insulating high-temperature-resistant plastic. The LED chip 16 is disposed on a thermally conductive but electrically insulating submount 18 , and both are disposed together on a metal heat sinking element 10 (usually a copper pillar). A reflector 14 may be disposed on the heat dissipation element 10 . The heat dissipation element 10 together with the diode chip 16 and the sub-mount 18 are placed in the reserved space in the glue. Electrodes of the diode chip 16 are connected to the lead frame 12 through wires (not shown). Finally, the colloid is covered by a preformed transparent colloid light-transmitting protective mirror cover 20 , which is filled with resin (not shown) to protect the diode chip 16 and the wires.

The structure proposed in US Patent No. 6,274,924 achieves quite effective heat dissipation due to the separation of electrical channels and heat dissipation channels. However, considering the above manufacturing process, the manufacturing process of US Patent No. 6,274,924 is quite complicated, and the production cost is not easy to reduce. Moreover, for example, the colloid covering the lead frame 12 and the light-transmitting protective mirror cover 20 all need to be molded and made in advance by plastic injection molding. The cost of mold opening is certainly a considerable burden, but the main The problem is that the flexibility in production is low. For example, if more than one diode chip 16 is to be packaged in the structure shown in FIG.

Contents of the invention

Therefore, the main purpose of the present invention is to provide a high-power light-emitting diode chip packaging structure and its manufacturing method. On the one hand, the electrical channel and the heat dissipation channel are completely separated to achieve excellent heat dissipation efficiency; It can be mass-produced to reduce the production cost, so as to solve the unsatisfactory aspects of heat dissipation and manufacturing process of the aforementioned existing packaging structure.

The high-power LED chip packaging structure proposed by the present invention at least includes a base, a reflector, a LED chip, and a plurality of wires connected to the LED chip, and a translucent filler or light-transmitting filler for protecting the LED chip and the wire. Protective mirror cover. The base is integrally formed of metal material and insulating material and has a flat shape. The metal material respectively constitutes a heat sink that is kept at an appropriate distance from the periphery of the base and penetrates through the upper surface of the base and the lower surface or side of the base; Electrodes that protrude from the surface or sides, respectively. The insulating material is located between the heat sink and the electrodes, so that the heat sink is insulatively bonded to any electrode and any two electrodes.

The packaged light-emitting diode chip is glued on the upper surface of the heat sink, and the positive and negative electrodes of the light-emitting diode chip are respectively connected to the electrodes on the upper surface of the base by the wires. The reflector is fixed on the base in an appropriate combination. The reflecting plate has a through hole through up and down to expose the light emitting diode chip on the cooling seat of the base, so that the light emitted by the light emitting diode chip can be emitted upward and outward. The reflector is made of metal material with high reflectivity, or is made of non-metal material but coated with high reflectivity film on the perforated wall surface. The through hole is filled with a translucent filler made of resin or similar transparent material or a translucent protective mirror cover to form a light channel and protect the light emitting diode chip and wires at the same time.

This packaging structure is suitable for mass production because the base structure is simple and integrally formed. The production method proposed by the present invention uses a large metal plate to simultaneously manufacture the bases of the packaging structural units of a plurality of light-emitting diode chips. The metal plate forms the heat sink and electrode pattern of the base of these packaged structural units by etching once or separately on both sides, and then fills the insulating material between the heat sink and the electrode, and glues the reflector on the base, and then the heat sink The upper surface is solidified, the chip is connected to the upper surface electrode of the base with wires, the light-transmitting material is filled in the through hole of the reflector, and finally each package structure unit is cut and separated.

Please cooperate with the accompanying drawings, the detailed description of the embodiments and the patent scope of the application, and describe the above and other purposes and advantages of the present invention in detail. However, it can be understood that the accompanying drawings are only for illustrating the spirit of the present invention, and should not be regarded as limiting the scope of the present invention. For the definition of the scope of the present invention, please refer to the claims.

Description of drawings

Fig. 1a is a side view of a conventional LED chip packaging structure;

Figure 1b shows a representative drawing of US Patent No. 6,274,924;

Figure 2a shows a side sectional view of a first embodiment of a packaging structure of the present invention;

Fig. 2b shows the structural exploded view of the first embodiment of the packaging structure of the present invention;

Figure 2c shows a side sectional view of a second embodiment of the packaging structure of the present invention;

Figure 2d is a side sectional view of a third embodiment of a packaging structure of the present invention;

FIG. 2e is a side sectional view of a fourth embodiment of a packaging structure of the present invention;

FIG. 2f is a side sectional view of a fifth embodiment of the packaging structure of the present invention;

Figure 3a shows a base and a perspective view of an embodiment of the present invention implemented in a dual chip package;

Fig. 3b shows a base and a perspective view of an embodiment of the present invention implemented in a three-chip package;

4a-4g show various steps of an embodiment of the manufacturing method of the present invention.

10 heat dissipation element 12 lead frame

13 Conductor 14 Reflector

15 Copper Foil 16 Diode Chip

17 resin 18 vehicles

20 Translucent protective mirror cover

100 base 102 heat sink

103 mirror surface 104 electrode

105 Phosphor 106 Insulator

110 reflector 120 wire

130 Translucent filler 150 Diode chip

160 Bonding agent 170 Translucent protective mirror cover

180 Frame 190 Metal Plate

200 Packaging structure unit 210 Reflecting plate body

Detailed ways

2a and 2b are side sectional views and structural exploded views of the first embodiment of the present invention. As shown in the figure, the high-power LED chip packaging structure of this embodiment at least includes a base 100 , a reflector 110 , a LED chip 150 , a plurality of wires 120 , and a translucent filler 130 . The base 100 is integrally formed by a heat sink 102 , a plurality of electrodes 104 , and an insulator 106 and has a flat shape. Both the heat sink 102 and the electrode 104 are made of metal materials with high conductivity and high thermal conductivity. The insulator 106 is made of resin or similar insulating material.

The heat sink 102 is located inside the base 100 , keeps an appropriate distance from the periphery of the base 100 , and protrudes from the upper surface of the base 100 and at least one of the lower surface and the side of the base 100 . In this embodiment, the heat dissipation seat 102 extends outwards and penetrates from other positions of the base 100 to increase the heat dissipation area. Please note that the shape of the heat sink 102 shown in FIGS. 2a and 2b is just an example and not limited to this shape. The electrodes 104 are located at proper positions around the heat sink 102 , and protrude from the upper surface of the base 100 , and at least one of the lower surface and the side surface respectively, so as to provide the external electrical connection of the diode chip 150 . Likewise, the shape of the electrode 104 shown in FIGS. 2a and 2b is just an example and not limited to this shape. In principle, in the case of the single crystal package of this embodiment, the number of electrodes 104 is two, while in other embodiments providing polycrystalline packages, the number of electrodes 104 is twice the number of chips. The rest of the base is filled with insulation 106 . The insulator 106 is therefore located between the heat sink 102 and the electrode 104 , so that the heat sink 102 is insulatively bonded to any electrode 104 and any two electrodes 104 . The manufacturing method of the base 100 will be explained in detail later.

The reflection plate 110 has a shape of a flat plate, and a perforation hole with a proper diameter and extending upwards and downwards is formed at a proper position inside it. The reflector 110 is made of a metal material with high reflectivity (such as aluminum), or is made of resin or similar insulating material but is coated with white coating on the perforated wall surface, or is coated with a film with high reflectivity (such as silver plating). ). The reflection plate 110 is adhered to the base 100 through a suitable adhesive 160 . When the reflector 110 is made of metal material, the bonding agent 160 also provides electrical insulation between the reflector 110 and the electrode 104 of the base 100 . The position and aperture of the perforation of the reflection plate 110 are properly set, so that after bonding with the base 100, the penetration of the heat sink 102 on the upper surface of the base 100 can be exposed for the penetration of the crystal bonding part and each electrode 104. Part of the area is at least enough for wiring. Therefore, when the LED chip 150 is placed on the upper surface through which the heat sink 102 penetrates, the light emitted by it can be emitted upwards and outwards through the through holes. Please note that in this embodiment, the perforation has a circular diameter and is wide at the top and narrow at the bottom, but this is only an example, and the geometric shape of the perforation is not limited thereto.

The LED chip 150 is bonded to the upper surface of the heat sink 102, and the positive and negative electrodes of the LED chip 150 are respectively connected to the upper surface of the electrode 104 of the base 100 through wires 120, thereby completely separating the electrical channel and the heat dissipation channel to achieve excellent performance. cooling effect. The perforations of the reflection plate 110 are filled with translucent fillers 130 made of resin or similar transparent materials to seal and protect components in the packaging structure such as the LED chips 150 and wires 120 . In this embodiment, the filler 130 is to completely fill the perforation of the reflector 110, but in the second and second embodiments shown in Figure 2c, it is also possible to use a light-transmitting protective mirror cover 170 as shown in the figure to make the luminous Diode chips 150, wires 120 and other components are protected or light-transmitting protective mirror covers (such as convex mirror covers) of other shapes.

Figures 2d, 2e and 2f show the third, fourth and fifth embodiments of the present invention. In the third embodiment shown in FIG. 2 d , a slightly concave reflective mirror surface 103 may be formed between the upper surface of the heat sink 102 and the LED chip 150 . The reflective mirror surface 103 can be formed by a reflective material of metal or metal compound (such as silver, aluminum, aluminum oxide, etc.) with thermal conductivity, or coated with a reflective material without thermal conductivity, so as to improve the performance of the LED chip 150 after packaging. brightness. The fourth embodiment shown in Fig. 2e is mainly aimed at the application of generating white light by exciting phosphors. In this embodiment, the blue light-emitting diode chip 150 is wrapped in the yellow phosphor 105 , and the yellow light generated by the phosphor 105 after being excited is complementary to the blue light used for excitation to generate white light with two wavelengths. Alternatively, the ultraviolet light-emitting diode chip 150 is wrapped in the red, green, and blue phosphor 105, and the three-color light generated after being excited by the phosphor 105 is converted into three-wavelength white light. The fifth embodiment shown in Fig. 2f is a comprehensive implementation of the third and fourth embodiments. There have been many related inventions and researches related to the mirror surface 103 and the excitation technology of the phosphor 105 , not limited to the aforementioned methods.

Figures 3a and 3b are perspective views of the submount 100 and package completion of embodiments of the present invention implemented in dual-die and triple-die packages. As shown in the figure, the packaging structure proposed by the present invention can be easily used to package a larger number of LED chips 150 , the only difference is that the appropriate number and positions of the electrodes 104 are formed on the base 100 . The polycrystalline package as shown in the figure is very suitable for achieving combinations of various colors of light. Taking the three-crystalline package shown in FIG. 3b as an example, the three LED chips 150 can be red, green, and blue LED chips respectively. 150, and the mixed light of these three colors forms white light. Based on the aforementioned embodiments, it can be clearly seen that the packaging structure proposed by the present invention can be applied to LED chips 150 of various colors, does not limit the number of LED chips 150, and can realize various single-light Combine with shades of full color.

4a-4g show various steps of an embodiment of the manufacturing method of the present invention. First, as shown in FIG. 4a, a large metal plate 190 with high electrical conductivity and high thermal conductivity is prepared to be used later to simultaneously form the bases 100 of multiple packaging structural units 200, and the formed bases 100 of these units are in a matrix form. In an arrangement, the unit bases 100 are connected to each other or to the frame 180 . The formation method is to use general etching and mechanical processing to etch away the part of the base 100 of each package structure unit that will be filled with the insulator 106 in the future, leaving only the heat sink 102 and the electrode 104. The result is shown in Figure 4b, and then Filling the etched part with the insulator 106 completes the manufacture of the base 100 of the plurality of packaging structural units 200, and the result is shown in FIG. 4c.

Depending on the shape and complexity of the heat sink 102 and the electrode 104 in the unit base 100, the aforementioned etching and machining can be performed on the upper and lower main surfaces of the metal plate 190, and all the heat sink 102 and electrodes 104 in the unit base 100 can be completed at one time. pattern formation, and then the insulator 106 is filled and bonded. Or, if the shapes of the heat sink 102 and the electrode 104 in the unit base 100 are quite complicated, one main surface of the metal plate 190 can be etched and filled with the insulator 106 first, and then the other main surface of the metal plate 190 can be etched. Etching and filling of the insulator 106 can complete the fabrication of all unit bases 100 .

Next, as shown in FIG. 4d , a pre-prepared board body 210 including a plurality of reflective boards 110 is adhered to the finished product in FIG. 4c with an appropriate adhesive (not shown). Then, as shown in FIG. 4 e , the die-bonding and wire-bonding of the light-emitting diode chip 150 are performed on each package structure unit 200 respectively. After the die-bonding and wire bonding of all the chips 150 are completed, the through-holes of each unit reflector 110 are filled with a translucent filler 130 such as resin to seal each package structure unit 200, and the result is shown in FIG. 4f. Finally, as shown in FIG. 4g , each package structure unit 200 is cut and separated.

With the help of the above detailed description of the preferred embodiments, it is hoped that the characteristics and spirit of the invention can be described more clearly, rather than the scope of the invention is limited by the preferred embodiments disclosed above. On the contrary, the purpose is to cover various changes and equivalent arrangements within the scope of the patent application for this creation.

Claims (16)

1. A packaging structure for a light-emitting diode chip, characterized in that it at least includes: at least one light emitting diode chip; A base is integrally formed by a heat sink, a plurality of electrodes, and an insulator. The heat sink and the electrodes are made of a metal material. The insulator is arranged on the heat sink and the electrodes. Between the plurality of electrodes, so that the heat sink and the plurality of electrodes are bonded together, and the heat sink is electrically insulated from any one of the electrodes, and between any two of the electrodes. The light emitting diode chip is glued to the upper surface of the heat sink; A reflective plate, bonded to the upper surface of the base by a suitable bonding agent, has a perforation with a proper diameter and penetrates up and down at an appropriate position inside it, so as to expose the upper surface of the heat sink for die bonding , and at least a partial area of the upper surface of the plurality of electrodes, the perforated inner wall has a high reflectivity; a plurality of wires connecting the electrodes of the light emitting diode chip and the plurality of electrodes; and A filler, made of a light-transmitting material, is located in the through hole of the reflection plate to seal the LED chip and the plurality of wires. 2. The package structure according to claim 1, wherein the heat dissipation seat of the base is located inside the base, keeping an appropriate distance from the periphery of the base, and is formed by the upper surface of the base and the At least one of the lower surface and the side of the base is respectively exposed. 3. The packaging structure according to claim 1, wherein the plurality of electrodes of the base are located at appropriate positions around the heat sink, and are formed by the upper surface of the base, the lower surface and the side surfaces of the base. At least one of the two is revealed separately. 4. The package structure according to claim 1, wherein the reflector is made of a metal material with high reflectivity. 5 . The package structure according to claim 1 , wherein the reflecting plate is made of an insulating material, and the through-hole wall has a high reflectivity white coating. 6 . 6 . The package structure according to claim 1 , wherein the reflection plate is made of an insulating material, and the wall surface of the through hole is coated with a film with high reflectivity. 6 . 7 . The package structure according to claim 1 , wherein there is a reflective mirror between the upper surface of the heat sink and the LED chip. 8. The package structure according to claim 1, wherein the LED chip is wrapped in a suitable fluorescent body. 9. A method for manufacturing a packaging structure of a light-emitting diode chip, characterized in that the packaging structure for simultaneously producing a plurality of light-emitting diode chips at least includes the following steps: (1) On a metal plate, a plurality of unit bases of the plurality of packaging structures are formed, each unit base includes a heat sink and a plurality of electrodes, and the plurality of electrodes maintain an appropriate distance from the heat sink, Between the heat dissipation seat of each unit base and the plurality of electrodes, an insulator is filled, so that between the heat dissipation seat of each unit base and the plurality of electrodes, and between the plurality of electrodes are insulating bonded; (2) Adhere a pre-prepared plate body of multiple reflectors containing the plurality of packaging structural units with the finished product completed in step (1) with an appropriate adhesive, and inside each reflector There is a perforation with a proper caliber at an appropriate position, which penetrates up and down and has a high reflectivity on the inner wall, so that after bonding, the perforation exposes at least part of the upper surface of the heat sink of a corresponding unit and the upper surface of the plurality of electrodes area; (3) On the upper surface of the heat sink of each unit, at least one light-emitting diode chip is solidified, and the electrodes of the light-emitting diode chip are respectively connected to the plurality of electrodes of the unit by a plurality of wires upper surface; (4) Cover the light-emitting diode chip and the plurality of wires exposed by the through hole with a light-transmitting filler in the through hole of each reflecting plate; and (5) Cutting and separating the plurality of packaging structural units. 10. The manufacturing method of the package structure according to claim 9, wherein the heat sinks of the plurality of unit bases are formed inside the unit base, keep an appropriate distance from the periphery of the unit base, and are formed by the plurality of unit bases. The upper surface of the unit base, and at least one of the lower surface and side surfaces of the unit base are respectively exposed. 11. The manufacturing method of the package structure according to claim 9, wherein the plurality of electrodes of the plurality of unit bases are formed at appropriate positions around the heat sink of the unit base, and are formed by the upper surface of the unit base , and at least one of the lower surface and the side surface of the unit base is respectively exposed. 12. The manufacturing method of the packaging structure according to claim 9, wherein the step (1) is carried out on the two main surfaces of the metal plate simultaneously by etching and metal processing, and then the insulator is filled and bonded , to form the plurality of unit bases. 13. The manufacturing method of the packaging structure according to claim 9, wherein in the step (1), a main surface of the metal plate is first filled with an insulator by etching and metal processing, and then The other major surface of the metal plate is filled with an insulator to form the plurality of unit bases. 14. The manufacturing method of the package structure according to claim 9, wherein the reflecting plate body is made of a metal material with high reflectivity. 15 . The manufacturing method of the packaging structure according to claim 9 , wherein the body of the reflecting plate is made of an insulating material, and the perforated wall of each reflecting plate has a white coating with high reflectivity. 16 . 16 . The manufacturing method of the packaging structure according to claim 9 , wherein the reflecting plate body is made of an insulating material, and the perforated wall surface of each reflecting plate is coated with a film with high reflectivity. 16 .

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