CN101814572A - Light-emitting diode packaging structure - Google Patents

Abstract

The present invention discloses a photodiode packaging structure, which is applied to a photodiode crystal, and the packaging structure comprises: a substrate having a first surface; a bearing space, the top opening of which is located on the first surface of the substrate, and the bottom of which is used to bear the photodiode crystal; and an optical material layer, which covers the photodiode crystal and has a microlens array structure, wherein the microlens array structure is located above the photodiode crystal to transmit the light emitted by the photodiode crystal and define the light type. The present invention can effectively improve the alignment and fixation problems caused by the relative displacement between the lens structure and the packaging base, and does not cause complicated processes and increased costs.

Description

Photodiode Package Structure

technical field

The invention relates to a photodiode packaging structure, in particular to a photodiode packaging structure applied to a photodiode crystal grain.

Background technique

Light Emitting Diode (Light Emitting Diode hereinafter referred to as LED) is a light-emitting device that can directly convert electrical energy into visible light and radiant energy. The principle of light emission is to apply voltage to the positive and negative terminals in the semiconductor. When combined with holes, the remaining energy is released in the form of light. Depending on the material used, the energy level makes the photon energy produce light of different wavelengths. Therefore, light-emitting diodes (LEDs) usually have low operating voltage, With a series of characteristics such as low power consumption, high luminous efficiency, extremely short luminous response time, pure light color, firm structure, impact resistance, vibration resistance, stable and reliable performance, light weight, small size and low cost, the development of light-emitting diodes can be said It is advancing by leaps and bounds, and now it can mass-produce high-brightness and high-performance products in various colors in the entire visible spectrum. The production process of light-emitting diodes (LEDs) in the industry can be mainly divided into the upstream is the production of light-emitting diode (LED) substrate chips and substrates, the midstream industry is the design and manufacture of light-emitting diode (LED) chips, and the downstream is light-emitting diode (LED) chip design and production. (LED) packaging and testing, among which the packaging of light-emitting diodes (LEDs) is an important key technology that affects whether the finished products of light-emitting diodes (LEDs) are excellent.

The packaging structure of light emitting diodes is to fix single or multiple light emitting diodes (LEDs) on the bracket or substrate, and connect the positive and negative electrodes of the light emitting diodes (LEDs) with the electrodes on the bracket or substrate by wire bonding or eutectic. The light-emitting diode (LED) is encapsulated with epoxy resin or silicone by dispensing glue or compression molding. Please refer to FIG. 1 , which is a schematic diagram of a known LED package structure with a lens structure. We can clearly see from the figure that the light emitting diode package structure 1 includes a package base 10 and a lens structure 11, wherein the package base 10 has a carrying space 12 for carrying a light emitting diode chip 100, and The lens structure 11 is bonded and fixed to the light-emitting surface 101 of the package base 10 through an adhesive 13 (for example, silicone resin (Silicone) or epoxy resin (Epoxy)). However, in the known LED packaging structure 1 with a lens structure, when the lens structure 11 is bonded to the package base 10, the lens structure 11 often cannot be accurately aligned with the light-emitting surface 101 of the package base 10. center point (marked by the triangle symbol in the figure), resulting in a deviation between the lens structure 11 and the package base 10, or in the bonding process, the adhesive 13 is not Both lead to the tilting of the lens structure 11 and the package base 10 .

2a-2c, which are schematic diagrams showing the offset or inclination of the lens structure 11 after bonding with the package base 10. Referring to FIG. As shown in FIGS. 2a and 2b, when the lens structure 11 is bonded to the package base 10, as shown in FIG. 2a, the lens structure 11 cannot be accurately aligned with the center of the light-emitting surface 101 of the package structure 10. point (indicated by the triangle symbol), as shown in FIG. 2b, the lens structure 11 will generate unidirectional (X direction) or bidirectional (X direction and Y direction) relative to the light-emitting surface 101 of the packaging structure 10. linear offset. As shown in FIG. 2 c , during the bonding process, the bonding glue 13 is deformed due to uneven application of force, resulting in a deflection angle of the lens structure 11 relative to the light-emitting surface 101 of the package base 10 . The above-mentioned poor bonding between the lens structure 11 and the package base 10 will cause the relative positional deviation of the light emitting diode die 100 and the lens structure 11 to be too large, resulting in a decrease in luminous efficiency and a light pattern. change. In addition, after the lens structure 11 is bonded to the package base 10, the following situation will occur. As shown in the top view of FIG. 2d, we can clearly see that if the lens structure 11 is inscribed on the package base 10, the lens structure 11 cannot completely cover the package base 10 (the four corners of the package base are exposed outside the package base 10 as shown in the figure), thus wasting the The area of the package base 10; in another case, as shown in the top view of FIG. Part of the lens structure 11 protrudes from the package base 10 , and the area of the lens structure 11 is wasted. Both of the above situations will result in an increase in production cost.

In order to improve the problems of alignment fixation and waste of production cost caused by the relative displacement between the lens structure and the package base, a micro lens optical system (Micro lens optical system) that can be combined with many optical components has been developed. As shown in Figures 3a to 3e, the spherical lens 200 (as shown in Figure 3a) is first produced by the photoresist thermal reflow method (Reflow process); then a polymer material 201 is cast (Cast) on the spherical lens in Figure 3a (as shown in Figure 3b); obtain a polymer material mold 202 (Figure 3c) after curing; then in the manner of spin coating, the material coating of microlens array 203 is coated on the polymer material obtained in Figure 3c on the mold 202 (as shown in FIG. 3 d ); finally, after a film release procedure is performed, an elastic microlens array 203 can be obtained. After the above description of the production procedure of the microlens array 203, we can clearly see that the known microlens array 203 must be manufactured through a series of casting film forming processes, and then the individual single lenses of the microlens array 203 The microlens structure is bonded to the package base of a single light-emitting diode to form a package structure as shown in FIG. problem, but such a complicated process will inevitably lead to an increase in production cost, therefore, how to improve the above-mentioned defects is the main purpose of the present invention.

Contents of the invention

In view of the defects of the prior art, the purpose of the present invention is to provide a photodiode packaging structure, which is applied to a photodiode crystal grain, and the packaging structure includes: a substrate, which has a first surface; a carrying space, which a top opening is located on the first surface of the substrate, and the bottom thereof is used to carry the photodiode die; and an optical material layer is formed in the carrying space and covers the photodiode die and has a microlens array structure, wherein the microlens array structure is located above the photodiode crystal grain, and is used to transmit the light emitted by the photodiode crystal grain. light type.

According to the above idea, in the photodiode packaging structure of the present invention, the substrate is a silicon semiconductor substrate with a (100) lattice direction, a (110) lattice direction or a (111) lattice direction.

According to the idea above, in the photodiode packaging structure of the present invention, the substrate is a ceramic substrate made of aluminum oxide or aluminum nitride.

According to the idea above, in the photodiode packaging structure of the present invention, the substrate is a metal substrate made of aluminum metal or copper metal.

According to the above idea, in the photodiode packaging structure of the present invention, the carrying space is surrounded by a plurality of slopes, and the included angle between the multiple slopes and the bottom of the carrying space is less than 90 degrees.

According to the idea above, in the photodiode packaging structure of the present invention, the shape of the carrying space is a cone, a cube, a rectangle, a semi-ellipse or a semi-cone.

According to the above idea, the photodiode packaging structure of the present invention further includes a via hole, the bottom opening of which is located on a second surface of the substrate, and the top of the via hole communicates with the bottom of the carrying space.

According to the idea above, in the photodiode packaging structure of the present invention, the optical material layer and the microlens array structure are a thermosetting or thermoplastic optical colloid with a certain light transmittance.

According to the above idea, in the photodiode packaging structure of the present invention, the optical material layer is a thermosetting or thermoplastic optical colloid with a certain light transmittance, and the microlens array structure is a photosensitive material, A thermosetting material or a thermoplastic material.

According to the above idea, in the photodiode packaging structure of the present invention, the microlens array structure is bonded on the optical material layer by a mold core or formed by a dry mold and bonded to the first surface of the substrate and The optical material is layered on top to finish.

According to the above idea, in the photodiode packaging structure of the present invention, the microlens array structure is composed of a plurality of microlens structures, and the microlens structures can be arc-curved upward hemispherical three-dimensional microstructures or two-axis Half-elliptical three-dimensional microstructures with varying lengths.

According to the idea above, in the photodiode packaging structure of the present invention, the plurality of microlens structures can be semi-spherical three-dimensional microstructures curved downwards or semi-elliptical three-dimensional microstructures with two axial lengths of different lengths.

According to the above idea, in the photodiode packaging structure of the present invention, the plurality of microlens structures can be a trihedral cone structure or a tetrahedron cone structure.

According to the idea above, in the photodiode packaging structure of the present invention, the microlens array structure is located on the first surface of the substrate or in the carrying space.

According to the idea above, in the photodiode packaging structure of the present invention, the photodiode die used is a light emitting diode or a laser diode.

The beneficial effect of the present invention is that it can effectively improve the problems of alignment and fixation caused by the relative displacement between the lens structure and the packaging base, without complicating the process and increasing the cost.

Description of drawings

FIG. 1 is a schematic diagram of a known LED package structure with a lens structure.

2a to 2e are schematic diagrams of the lens structure being bonded to the package base to cause offset or inclination and waste the area of the package base.

3a to 3e are schematic flow charts of a manufacturing method of a microlens array.

FIG. 4 is a schematic diagram of the first preferred embodiment of the photodiode packaging structure of the present invention.

FIGS. 5 a to 5 c are schematic flowcharts of the manufacturing method of the microlens array structure contained in the photodiode package base structure described in the first preferred embodiment of the present invention.

6a to 6b are schematic diagrams of the second preferred embodiment of the photodiode packaging structure of the present invention.

7a to 7d are schematic diagrams of embodiments of different shapes of a plurality of microlens structures included in the microlens array structure.

Wherein, the reference signs are explained as follows:

LED package structure 1 package base 10

Lens structure 11 Bearing space 12

Adhesive 13 LED Die 100

Light-emitting surface 101

Spherical lens 200 Polymer material 201

Polymer material mold 202 microlens array 203

LED Die 200

Photodiode Package Structure 3

Substrate 30 Bearing space 31

Via holes 32, 33 Optical material layer 34

Microlens array structure 35 first surface 301

Second surface 302 Inclined surface 306

Microlens mold core 3016 photodiode grain 300

Substrate 40 Bearing space 41

Via holes 42, 43 Optical material layer 44

Microlens array structure 45 first surface 401

Second surface 402 Inclined surface 406

Micro lens mold core 4016 photodiode grain 400

Semi-elliptical microlens structure 50

60 microlens structures with circular arcs and downward semicircles

Arc curved downward semi-elliptical microlens structure 70

Tapered Microlens Structure 80

Detailed ways

Please refer to FIG. 4, which is a schematic diagram of a first preferred embodiment of a photodiode packaging structure developed by the present invention to improve the defects produced by the existing photodiode packaging structure, and the packaging structure described in the present invention is applied to a During the packaging process of the photodiode die 300 of a light emitting diode (LED) or a laser diode (Laser Diode). We can clearly see from the figure that the photodiode package structure 3 of the present invention includes a substrate 30 having a first surface 301 and a second surface 302, a carrying space 31, and via holes 32, 33 , an optical material layer 34 and a microlens array structure 35, wherein the substrate 30 is a silicon semiconductor substrate with a (100) lattice direction, a (110) lattice direction or a (111) lattice direction, such semiconductor The substrate can provide heat dissipation with high thermal conductivity. In addition, the material of the substrate 30 can also be a ceramic substrate made of aluminum oxide or an aluminum nitride material, or a metal substrate made of an aluminum metal or a copper metal. , can also provide heat dissipation with high thermal conductivity; the carrying space 31 is mainly surrounded by a plurality of slopes 306, and its top opening is located on the side of the first surface 301 of the substrate 30, and the bottom of the carrying space 31 is mainly used for carrying the photodiode crystal grain 300; the bottom opening of the via hole 32 is located on the second surface 302 side of the substrate 30, and the top of the via hole 32, 33 is connected to the bottom of the carrying space 31, and this The most important technical means of the photodiode packaging structure described in the invention is that the carrying space 31 has the optical material layer 34 covering the photodiode die 300, and the optical material layer 34 is connected with the microlens The array structure 35, the microlens array structure 35 is located above the photodiode crystal grain 300, and is mainly used to transmit the light emitted by the photodiode crystal grain 300. At the same time, the shape of a single microlens and the arrangement of the array can effectively Improve the light efficiency and change the light type. The photodiode package structure described in the present invention will be described in detail below.

According to the above technical description, usually the carrying space 31 and the via holes 32, 33 located on the first surface 301 and the second surface 302 of the substrate 30 are connected via the first surface 301 and the second surface 302 of the substrate 30. The second surface 302 is etched to complete, according to the lattice characteristics of the substrate 30, the carrying space is formed on the first surface 301 and the second surface 302, and the angle between the bottom and the slope 306 is less than 90 degrees. 31, the via holes 32, 33, and the bearing space surrounded by a plurality of slopes 306 can be in the shape of a cone, a cube, a rectangle, a semi-ellipse or a semi-cone. The optical material layer 34 is a thermosetting (such as: silica gel, epoxy resin) or a thermoplastic (such as: polyester with high glass transition temperature...) optical colloid with a certain light transmittance, The microlens array structure 35 is a photosensitive material (such as: photoresist), a thermosetting material or a thermoplastic material.

Please refer to FIG. 5 a to FIG. 5 ( c ), which are schematic flowcharts of the manufacturing method of the microlens array structure 35 contained in the photodiode package base structure 3 described in the first preferred embodiment of the present invention. We can clearly see from the figure that the microlens structure 35 is mainly completed through a molding process, and its step flow can be clearly seen from Figures 5a to 5c. First, as shown in Figure 5a, we Coat another optical material layer 350 on the original optical material layer 34 (this optical material layer 350 can be made by using silica gel); as shown in FIG. On the layer 350; as shown in FIG. In addition, the microlens array structure 35 can also be formed in the form of a dry mold and then directly attached to the first surface 301 of the substrate 30 .

Please refer to FIG. 6 a and FIG. 6 b , which are schematic diagrams of a second preferred embodiment of a photodiode packaging structure developed by the present invention to improve the defects of the known photodiode packaging structure. From FIG. 6a we can clearly see that the photodiode package structure 4 of the present invention includes a substrate 40 having a first surface 401 and a second surface 402, a carrying space 41, a via hole 42, 43. An optical material layer 44. The difference between the photodiode packaging structure 4 described in this embodiment and the first preferred embodiment is that we only form the optical material layer 44 in the carrying space 41, and no further In addition, another optical material layer is formed on the optical material layer 44 to make a microlens array structure, that is, the microlens array structure 45 in this embodiment is integrally formed with the optical material layer 44, and the method for making it is as follows As shown in FIG. 6b, a microlens mold core 4016 is directly pressed onto the uncured optical material layer 44, and then the microlens mold core 4016 can be formed on the optical material layer 44 as shown in FIG. 6a. The microlens array structure shown in 45. However, some technical means of this preferred embodiment are the same as those of the first preferred embodiment, so details will not be repeated here.

The microlens mold cores 3016, 4016 described above in the first preferred embodiment and the second preferred embodiment are mainly carried out by a volume expansion method, a hot melt method, a surface tension method or a hot extrusion method. production, and then complete the microlens mold cores 3016, 4016 through a molding process.

In addition, in the manufacturing process steps of the above-mentioned different embodiments, we can clearly see that the thickness of the optical material layer 34, 44 determines the formation position of the microlens array structure 35, 45, for example, in FIG. 4, the microlens array structure The forming position of the lens array structure 35 is located on the first surface 301 of the substrate 30, and in FIG. 6a, the forming position of the microlens array structure 45 is located in the carrying space 31. As a preferred embodiment of the present invention, the optical material layer 34, 44 can also be coated with a uniform thickness along the periphery of the photodiode die 300, 400, and the optical material layer 34, 44 does not necessarily need to be coated with a uniform thickness. 44 to fill up the bearing space 31,41.

Please refer to FIG. 7 a to FIG. 7 d , which are schematic diagrams of embodiments of different shapes of the microlens array structures 35 , 45 . In the description of the above-mentioned first preferred embodiment and the second preferred embodiment, the multiple micro-lens structures included in the micro-lens array structures 35, 45 are all described by taking a hemispherical three-dimensional structure as an example, However, in addition to the hemispherical three-dimensional microstructure, the plurality of microlens structures included in the microlens array structure of the present invention can also be semi-elliptical with different axial lengths as shown in Figure 7a Three-dimensional microstructure 50, a hemispherical three-dimensional microstructure 60 with a curved downward arc as shown in FIG. . A trihedral or tetrahedral pyramidal structure 80 as shown in FIG. 7d.

Based on the above descriptions of different embodiments, we can clearly understand that the photodiode structure completed by the technical means of the present invention does solve the defects of the known packaging structure, and then realize the main purpose of the present invention . Those skilled in the art should realize that changes and modifications made without departing from the scope and spirit of the present invention disclosed by the appended claims of the present invention are within the protection scope of the claims of the present invention.

Claims (10)

1. A photodiode package structure applied to a photodiode crystal grain, the package structure comprising: a substrate having a first surface; a carrying space, the top opening of which is located on the first surface of the substrate, and the bottom of which is used to carry the photodiode die; and An optical material layer, which is formed in the carrying space and covers the photodiode crystal grain and has a microlens array structure, wherein the microlens array structure is located above the photodiode crystal grain for transmitting the light The light emitted by the diode die and the defined light pattern. 2. The photodiode packaging structure according to claim 1, wherein the substrate is a silicon semiconductor substrate with a (100) lattice direction, a (110) lattice direction or a (111) lattice direction Or a ceramic substrate made of an aluminum oxide or an aluminum nitride material, or a metal substrate made of an aluminum metal or a copper metal. 3. The photodiode packaging structure according to claim 1, wherein the carrying space is surrounded by a plurality of slopes, and the angle between the multiple slopes and the bottom of the carrying space is less than 90 degrees, and the carrying space The shape of the space is a cone, a regular cube, a rectangle, a half ellipse or a half cone. 4. The photodiode packaging structure according to claim 1, wherein the photodiode packaging structure further comprises a via hole, the bottom opening of which is located on a second surface of the substrate, the via hole The top of the bearing space communicates with the bottom of the carrying space. 5. The photodiode packaging structure according to claim 1, wherein the optical material layer and the microlens array structure are a thermosetting or thermoplastic optical colloid with a certain light transmittance . 6. The photodiode packaging structure according to claim 1, wherein the optical material layer is a thermosetting or thermoplastic optical colloid with a certain light transmittance, and the microlens array The structure is a photosensitive material, a thermosetting material or a thermoplastic material. 7. The photodiode package base structure according to claim 1, wherein the microlens array structure is bonded to the optical material layer by a mold core or formed by a dry mold and bonded to the substrate The first surface is made with the layer of optical material. 8. The photodiode packaging base structure according to claim 1, wherein the microlens array structure is composed of a plurality of microlens structures, and the plurality of microlens structures are arc-curved upward Hemispherical three-dimensional microstructure or arc curved upward two-axis semi-elliptical three-dimensional microstructure with different lengths or arc curved downward hemispherical three-dimensional microstructure or arc curved downward two axes The semi-elliptical three-dimensional microstructure with different lengths is either a trihedral cone microstructure or a tetrahedron cone microstructure. 9 . The photodiode package structure according to claim 1 , wherein the microlens array structure is located on the first surface of the substrate or in the carrying space. 10 . The photodiode package structure according to claim 1 , wherein the photodiode die used is a light emitting diode or a laser diode. 11 .

Images