LED packaging structure for yellow light chamber

Abstract

The utility model discloses an LED packaging structure for a yellow light chamber, and belongs to the technical field of semiconductors. Comprising a lead frame; the bowl cup is positioned on the upper surface of the lead frame and is internally provided with an accommodating cavity; the at least one blue light chip is positioned in the bowl cup accommodating cavity and is fixedly connected with the lead frame; the fluorescent glue layer is located in the bowl cup containing cavity and wraps the blue light chip; and the high-folding glue layer is positioned in the bowl cup accommodating cavity and is arranged at the upper part of the fluorescent glue layer. According to the utility model, the volume distribution of different layers and the height distribution of different layers of the bowl containing cavity are creatively carried out, and the high folding glue layer is additionally arranged, so that the energy of blue light is reduced, the purity of yellow light is improved, and the overall brightness of the LED is improved.

Description

Technical Field

[0001] The utility model relates to a yellow light room LED packaging structure, belonging to the technical field of semiconductors. Background Art

[0002] LED (light emitting diode) has many advantages, such as energy saving, long life, high luminous efficiency, no radiation, impact resistance, etc. More and more traditional lighting fixtures are being replaced by LED lamps, and the application scope of LED is still expanding and promoting.

[0003] Photoresist Room is a photolithography process used in semiconductor device manufacturing. In semiconductor processing, the photoresist room is used to expose the coating of photosensitizer to form light shadows on the surface, which can be processed through other processing steps to form the desired device structure.

[0004] The wavelength range of yellow light is about 570nm to 620nm, which is far away from the UV range, so it will not cause accidental exposure of the photoresist; yellow light usually does not contain ultraviolet rays, and photosensitive materials are protected from unnecessary exposure; yellow light is softer and more friendly to the human eye, reducing eye fatigue and irritation.

[0005] At present, the lamps used in semiconductor yellow light rooms generally have two methods: using white light tubes with yellow light masks to produce yellow light, and using yellow light chips to produce yellow light. The first method may cause the yellow light mask to age and cause the wavelength to change. The second method uses LEDs with yellow light chips, which have many problems such as low light efficiency, low thermal brightness, low reliability, and short life. Utility Model Content

[0006] The purpose of the utility model is to provide a yellow light indoor LED packaging structure with high luminous efficiency, low luminous decay and long life in view of the deficiencies of the above-mentioned prior art, so as to achieve the purpose of LED having no blue light or extremely low blue light intensity ratio and yellow light color.

[0007] The technical solution of the utility model is as follows:

[0008] A yellow light room LED packaging structure, characterized in that it comprises:

[0009] a lead frame having metal electrodes;

[0010] The bowl is located on the upper surface of the lead frame and has a cavity inside;

[0011] At least one blue light chip is located in the bowl-cup cavity and fixed to the lead frame; the blue light chip is electrically connected to the metal electrode through a bonding wire;

[0012] The fluorescent glue layer is located in the bowl cavity and wraps the blue light chip;

[0013] The high-fold adhesive layer is located in the bowl-cup cavity and is arranged on the upper part of the fluorescent adhesive layer; the top of the high-fold adhesive layer is flush with or slightly concave to the top of the bowl-cup.

[0014] With the above LED packaging structure, the fluorescent glue layer is formed by a transparent colloid mixed with fluorescent powder, and the density and composition of the fluorescent powder are set according to actual needs; the high-fold glue layer has a high refractive index, high bonding strength, and can withstand large tensile and shear forces. When working, the blue light chip is powered on to emit blue light, which excites the fluorescent powder in the fluorescent glue layer, and finally passes through the high-fold glue layer to present yellow light. The blue light chip has the advantages of high stability and high electro-optical efficiency. On the basis of meeting the function of the yellow light room, the LED has the advantages of high light efficiency, low light decay, high reliability and long life.

[0015] Furthermore, in the bowl cup cavity, the fluorescent glue layer is divided from bottom to top into a first fluorescent glue layer and a second fluorescent glue layer with the upper surface of the blue light chip as the boundary; the sum of the volumes of the second fluorescent glue layer and the high-fold glue layer is 2-2.5 times the volume of the first fluorescent glue layer; the sum of the heights of the second fluorescent glue layer and the high-fold glue layer is 1.5-2 times the height of the first fluorescent glue layer, and the height of the high-fold glue layer is 0.02-0.1mm.

[0016] Since the blue light chip excites the phosphor in the fluorescent glue layer to emit yellow light, the proportion of blue light intensity cannot be controlled, which easily leads to a high proportion of blue light intensity and low overall brightness of the LED, resulting in the overall light source specification characteristics not meeting the application requirements of the semiconductor workshop. Therefore, the utility model innovatively has specific requirements for the volume of the bowl and cup cavity, the volume distribution of different layers, and the height distribution of different layers, and adds a high-fold glue layer to the third layer, thereby reducing the energy of blue light, improving the purity of yellow light, and improving the overall brightness of the LED.

[0017] Furthermore, the bowl-cup cavity is narrow at the bottom and wide at the top, so that the inner wall of the bowl-cup cavity forms an obtuse angle with the upper surface of the lead frame, and the light emitted by the blue light chip can be reflected by the inner wall of the cavity before being emitted from the cavity, ultimately obtaining a larger light output angle and absorbing the blue light energy to the maximum extent. The inner contour line of the bowl-cup cavity is an oblique straight line, which can facilitate the reflection of the light of the blue light chip without interfering with the light output, and can facilitate the smooth sedimentation of the phosphor in the phosphor glue layer, and no phosphor deposition will be generated on the inner wall of the cavity, thereby ensuring the uniformity of light output and the absorption of blue light.

[0018] Furthermore, under the conditions of satisfying the volume distribution of different layers of the bowl-cup cavity and the height distribution of different layers, the bowl-cup cavity can also adopt a cylindrical structure, that is, the inner contour line of the bowl-cup cavity is a vertical line perpendicular to the lead frame.

[0019] Furthermore, the bottom of the bowl-cup cavity is provided with a circle of steps along its circumference, and a gap is left between the steps and the blue light chip. The utility model adds steps (made of the same material as the bowl-cup) to block blue light, change the light path, and prevent blue light from leaking from the bowl-cup wall; the steps at the bottom of the cavity can also allow the phosphor to accumulate at a high density and cover around the blue light chip, reducing the blue light energy and improving the overall yellow light brightness. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of the LED packaging structure for yellow light room of the utility model;

[0021] Figure 2 It is the spectrogram in Example 5;

[0022] Figure 3 It is the spectrogram in Example 5;

[0023] In the figure: 1 first fluorescent glue layer, 2 second fluorescent glue layer, 3 high fold glue layer, 4 blue light chip, 5 steps, 6 lead frame, 7 bowl and cup, 8 bonding wire. DETAILED DESCRIPTION

[0024] Example 1

[0025] A yellow light room LED packaging structure, such as Figure 1 As shown, it includes: a lead frame 6, a cup 7, a blue light chip 4, a fluorescent glue layer (including a first fluorescent glue layer 1, a second fluorescent glue layer 2), and a high-fold glue layer 3. Among them:

[0026] The lead frame 6 has a metal electrode, and a cup 7 is formed on the upper surface of the lead frame 6, and a cavity is provided inside the cup; the blue light chip 4 is located in the cavity of the cup 7, and the bottom of the blue light chip 4 is fixedly connected to the lead frame 6, and the blue light chip 4 is also electrically connected to the metal electrode of the lead frame 6 through a bonding wire 8;

[0027] The density and composition of the fluorescent powder are set according to actual needs, and the fluorescent glue layer is coated in the cavity of the bowl cup 7 and wraps the blue light chip 4; the high fold glue layer 3 is coated in the cavity of the bowl cup 7 and is arranged on the upper part of the fluorescent glue layer, and the top of the high fold glue layer 3 is flush with the top of the bowl cup 7;

[0028] Taking the upper surface of the blue light chip as the boundary, the fluorescent glue layer is divided from bottom to top into a first fluorescent glue layer 1 and a second fluorescent glue layer 2; the sum of the volumes of the second fluorescent glue layer and the high-folding glue layer is 2-2.5 times the volume of the first fluorescent glue layer; the sum of the heights of the second fluorescent glue layer and the high-folding glue layer is 1.5-2 times the height of the first fluorescent glue layer, and the height of the high-folding glue layer is 0.02-0.1mm.

[0029] Example 2

[0030] The bottom of the bowl-cup cavity is provided with a circle of steps 5 along its circumference, and a gap is left between the steps and the blue light chip.

[0031] Example 3

[0032] Based on Example 2, the bowl-cup cavity has a structure that is narrow at the bottom and wide at the top, and the inner contour line of the bowl-cup cavity is an oblique straight line, so that the inner cavity wall of the bowl-cup cavity forms an obtuse angle with the upper surface of the lead frame.

[0033] Example 4

[0034] Based on the second embodiment, the bowl-cup cavity may also adopt a cylindrical structure, and the inner contour line of the bowl-cup cavity is a vertical line perpendicular to the lead frame.

[0035] Example 5

[0036] Based on Example 3, the total height of the bowl and cup cavity is 0.55mm; the length, width and height of the second fluorescent adhesive layer 2 are 2.56mm, 1.87mm and 0.33mm respectively, and the height of the high fold adhesive layer is 0.02mm. The sum of the volumes of the second fluorescent adhesive layer and the high fold adhesive layer is 1.67mm. 3 The length, width and height of the first fluorescent glue layer 1 are 2.24 mm, 1.55 mm and 0.2 mm respectively, so the volume of the first fluorescent glue layer is 0.69 mm 3 The length, width and height of the blue light chip are respectively: 0.445, 0.889, 0.2 mm or 0.572, 1.029, 0.2 mm. The yellow light room LED packaging structure prepared by the scheme in this embodiment is used to conduct relevant performance tests:

[0037] like Figure 2 As shown in the spectrum diagram, the LED prepared by this embodiment can achieve a blue light intensity in the range of 380-500nm accounting for less than 1% of the visible light range of 380-780nm; Figure 2 It is shown as 0.2%, that is, the sum of the light intensity within the wavelength of 380~500nm accounts for 0.20% of the sum of the light intensity within the wavelength of 380~780nm. The blue light energy is very low;

[0038] like Figure 3 As shown in the spectrum diagram, the LED prepared by this embodiment can achieve that the blue light intensity in the range of 380-525nm accounts for less than 1% of the visible light range of 380-780nm; Figure 3 It is shown as 0.16%, that is, the sum of the light intensity within the wavelength of 380~525nm accounts for 0.16% of the sum of the light intensity within the wavelength of 380~80nm. The blue light energy is very low;

[0039] The LED in this embodiment is placed in a high temperature and high humidity environment of 85°C and 85RH%, and is lit for a long time. After 6000 hours, the light decay is 5%, and the blue light intensity ratio is maintained at 0.2% (the wavelength range of blue light is 380~500nm);

[0040] The LED in this embodiment is placed in a high temperature environment of 85°C and is lit for a long time. After 6000 hours, the light decay is 4%, and the proportion of blue light intensity is maintained at 0.2% (the wavelength range of blue light is 380~500nm).

Claims

1. A yellow light room LED packaging structure, characterized in that: include: Lead frame (6); The cup (7) is located on the upper surface of the lead frame and has a cavity therein; at least one blue light chip (4) is located in the cup cavity and is fixedly connected to the lead frame; the bottom of the cup cavity is provided with a circle of steps (5) along its circumference, and a gap is left between the steps and the blue light chip; The fluorescent glue layer is located in the bowl-cup cavity and wraps the blue light chip; the fluorescent glue layer is divided from bottom to top into a first fluorescent glue layer (1) and a second fluorescent glue layer (2) with the upper surface of the blue light chip as the boundary; The high-fold adhesive layer (3) is located in the bowl cup cavity and is arranged on the upper part of the fluorescent adhesive layer; the sum of the volumes of the second fluorescent adhesive layer and the high-fold adhesive layer is 2-2.5 times the volume of the first fluorescent adhesive layer; the sum of the heights of the second fluorescent adhesive layer and the high-fold adhesive layer is 1.5-2 times the height of the first fluorescent adhesive layer; the height of the high-fold adhesive layer is 0.02-0.1 mm, and the top of the high-fold adhesive layer is flush with or slightly concave to the top of the bowl cup.

2. The yellow light room LED packaging structure according to claim 1, characterized in that: The bowl and cup cavity is narrow at the bottom and wide at the top, and the inner contour line of the bowl and cup cavity is an oblique straight line.

3. The yellow light room LED packaging structure according to claim 1, characterized in that: The bowl and cup cavity is in a cylindrical structure.

4. The yellow light room LED packaging structure according to claim 1, characterized in that: The lead frame has a metal electrode, and the blue light chip is electrically connected to the metal electrode via a bonding wire (8).

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