This application claims the benefit and priority of Korean Patent Application No. 10-2015-0161721, filed Nov. 18, 2015. The entire disclosure of the above application is incorporated herein by reference.
The present disclosure relates generally to a frame for a semiconductor light emitting device, and more particularly to a frame for a semiconductor light emitting device with improved light extraction efficiency.
This section provides background information related to the present disclosure which is not necessarily prior art. Unless specified otherwise, it is appreciated that throughout the description, directional terms, such as upper side/lower side, over/below and so on are defined with respect to the directions in the accompanying drawings.
In this semiconductor light emitting chip, there is provided a growth substrate 10 (e.g., a sapphire substrate), and layers including a buffer layer 20, a first semiconductor layer 30 having a first conductivity (e.g., an n-type GaN layer), an active layer 40 adapted to generate light by electron-hole recombination (e.g., INGaN/(In)GaN MQWs) and a second semiconductor layer 50 having a second conductivity different from the first conductivity (e.g., a p-type GaN layer) are deposited over the substrate in the order mentioned. A light-transmitting conductive film 60 for current spreading is then formed on the second semiconductor layer, followed by an electrode 70 serving as a bonding pad formed on the light-transmitting conductive film, and an electrode 80 (e.g., a Cr/Ni/Au stacked metallic pad) serving as a bonding pad is formed on an etch-exposed portion of the first semiconductor layer 30. This particular type of the semiconductor light emitting chip as in
In this semiconductor light emitting chip, there is provided a growth substrate 10, and layers including a first semiconductor layer 30 having a first conductivity, an active layer 40 adapted to generate light by electron-hole recombination and a second semiconductor layer 50 having a second conductivity different from the first conductivity are deposited over the substrate in the order mentioned. Three-layered electrode films 90, 91 and 92 adapted to reflect light towards the growth substrate 10 are then formed on the second semiconductor layer, in which first electrode film 90 can be a reflective Ag film, second electrode film 91 can be a Ni diffusion barrier, and third electrode film 92 can be an Au bonding layer. Further, an electrode 80 serving as a bonding pad is formed on an etch-exposed portion of the first semiconductor layer 30. Here, the side of the electrode film 92 serves as a mounting face during electrical connections to outside. This particular type of the semiconductor light emitting chip as in
The semiconductor light emitting device 100 is provided with lead frames 110 and 120, a mold 130, and a vertical type light-emitting chip 150 in a cavity 140 which is filled with an encapsulating member 170 containing a wavelength converting material 160. The lower face of the vertical type light-emitting chip 150 is directly electrically connected to the lead frame 110, and the upper face thereof is electrically connected to the lead frame 120. A portion of the light coming out of the vertical type light-emitting chip 150 excites the wavelength converting material 160 such that light of a different color is generated, and these two different lights are mixed to produce white light. For instance, the semiconductor light emitting chip 150 generates blue light, and the wavelength converting material 160 is excited to generate yellow light. Then these blue and yellow lights can be mixed to produce white light. Even though the semiconductor light emitting device shown in
In this regard, the present disclosure is directed to provide a frame for a semiconductor light emitting device adapted to receive a semiconductor light emitting chip, thereby allowing electrodes of a semiconductor light emitting chip used in the semiconductor light emitting device to bond directly to an external substrate. More particularly, the present disclosure is directed to provide a frame for a semiconductor light emitting device using a flip chip, in which no bonding between lead frames and the flip chip is required such that no light intensity from the flip chip would be lost due to bonding between the lead frames and the flip chip despite the use of the flip chip.
The problems to be solved by the present disclosure will be described in the latter part of the best mode for carrying out the invention.
This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features.
According to one aspect of the present disclosure, there is provided a frame for a semiconductor light emitting device to receive a semiconductor light emitting chip, the frame including: a side wall; and a bottom part which is connected to the side wall and has at least one hole for receiving a semiconductor light emitting chip.
The advantageous effects of the present disclosure will be described in the latter part of the best mode for carrying out the invention.
Hereinafter, the present disclosure will now be described in detail with reference to the accompanying drawings. The detailed description herein is presented for purposes of illustration only and not of limitation. The scope of the invention is defined by the appended claims. For example, the steps recited in any of the method or process descriptions may be executed in any order and are not necessarily limited to the order presented. Furthermore, any reference to singular includes plural embodiments, and any reference to more than one component or step may include a singular embodiment or step. Also, the steps recited in any of the method or process descriptions may be executed in any order and are not necessarily limited to the order presented. For convenience in explanation and for better understanding of a frame for a semiconductor light emitting device, the following description will mainly focus on a semiconductor light emitting device where a semiconductor light emitting chip is received in a corresponding frame for a semiconductor light emitting device.
The semiconductor light emitting device 200 includes a frame 210 for a semiconductor light emitting device, a semiconductor light emitting chip 220 and an encapsulating member 230.
The frame 210 for a semiconductor light emitting device has a side wall 211 and a bottom part 212. The bottom part 212 has a hole 213 therein. The frame 210 for a semiconductor light emitting device also includes a cavity 214 defined by the side wall 211 and the bottom part 212. The bottom part 212 has an upper face 215 and a lower face 216. The side wall 211 has an outer face 217 and an inner face 218. The side wall 211 may have height H smaller than length L of the bottom part 212. For instance, the height H of the side wall 211 may range from 0.1 mm to 0.6 mm, end points inclusive, and the length L of the bottom part 212 may be 0.5 mm or more. If appropriate, the side wall 211 may be omitted (not shown). It is desirable that the hole 213 is as large as the semiconductor light emitting chip 220 or 1.5 times larger than the semiconductor light emitting chip 220. Moreover, it is desirable that the lateral part 240 of the hole 213 is slanted in order to improve the efficiency of light extraction.
The semiconductor light emitting chip 220 is received into the hole 213. Examples of the semiconductor light emitting chip 220 may include a lateral chip, a vertical chip and a flip chip. The flip chip is preferentially used considering that the electrodes 221 of the semiconductor light emitting chip in the present disclosure are exposed towards the lower face 216 of the bottom part 212 of the frame 210 for a semiconductor light emitting device. It is desirable that the bottom part 212 has a height 219 less than a height 222 of the semiconductor light emitting chip 220. This is so because when the height 219 of the bottom part 212 is greater than the height 222 of the semiconductor light emitting chip 220, the efficiency of light extraction of the semiconductor light emitting device 200 may fall. Despite a possible decrease in the efficiency of light extraction, the bottom part 212 may be configured to have the height 219 greater than the height of the semiconductor light emitting chip 220, taking other factors such as an optical path into consideration. The height 219 of the bottom part 212 and the height 222 of the semiconductor light emitting chip 220 can be measured with respect to the lower face 216 of the bottom part 212. The height 222 of the semiconductor light emitting chip 220 may range from 0.05 mm to 0.5 mm, end points inclusive. The height 219 of the bottom part 212 may range from 0.08 mm to 0.4 mm, end points inclusive.
The encapsulating member 230 is provided at least to the cavity 214 and serves to cover the semiconductor light emitting chip 220 such that the semiconductor light emitting chip 220 received into the hole 213 can be fixed to the frame 210 for a semiconductor light emitting device. The encapsulating member 230 is light transmissive and may be made of either epoxy resins or silicone resins. If necessary, the encapsulating member 230 can have a wavelength converting material 231. Any material (e.g., pigments, dyes or the like) can be used for the wavelength converting material 231, provided that it converts light generated from the active layer of the semiconductor light emitting chip 220 into light having a different wavelength, yet it is desirable to use phosphors (e.g., YAG, (Sr,Ba,Ca)2SiO4:Eu or the like) in terms of the efficiency of light conversion). In addition, the wavelength converting material 231 can be selected depending on the color of light from a semiconductor light emitting device, which again is well known to those skilled in the art.
The semiconductor light emitting device 300 includes a bonding part 330. Apart from the bonding part 330, the frame 310 for a semiconductor light emitting device has the same configurational features with the frame 210 for a semiconductor light emitting device as shown in
The semiconductor light emitting device 400 includes a reflecting layer 430 formed at at least one of the inner faces 413 of the side wall 411 of the frame 410 for a semiconductor light emitting device and the upper face 414 of the bottom part 412 of the frame 410 for a semiconductor light emitting device. Apart from the reflecting layer 430, the frame 410 for a semiconductor light emitting device has the same configurational features with the frame 310 for a semiconductor light emitting device shown in
The semiconductor light emitting device 500 has plural holes 512 formed in the bottom part 511 of the frame 510 for a semiconductor light emitting device, and each of the holes 512 receives a semiconductor light emitting chip 520. Apart from these plural holes 512, with each of the holes 512 receiving an individual semiconductor light emitting chip 512, the frame 512 for a semiconductor light emitting device has the same configurational features with the frame 310 for a semiconductor light emitting device shown in
The semiconductor light emitting device 600 has a reinforcement member 620 in the frame 610 for a semiconductor light emitting device. Apart from the reinforcement member 620, the frame 610 for a semiconductor light emitting device has the same configurational features with the frame 210 for a semiconductor light emitting device shown in
The semiconductor light emitting device 600 has reinforcement members 620, and
The semiconductor light emitting device 700 has a reinforcement member 720, and the reinforcement member 720 contains therein a protecting element 740 (e.g., a Zener diode or a PN diode) for protecting the semiconductor light emitting chip 730 from static electricity or a reverse current, as shown in
The frame 800 for a semiconductor light emitting device can be obtained by injection molding. Once a substrate 810 including plural frames 800 for a semiconductor light emitting device as shown in
The semiconductor light emitting device 900 includes a frame 910 for a semiconductor light emitting device with a side wall 911 having a protruded portion 912. and a lens 920 formed on the encapsulating member and between the protruded portions 912. The other configurational features not described in reference to
The semiconductor light emitting device 1000 includes a frame 1100 for a semiconductor light emitting device, with the frame 1100 having at least one of concave and convex portions on the upper face 1111 of the bottom part 1110 thereof. In particular, the upper face 1111 of the bottom part 1110 of the frame 1100 for a semiconductor light emitting device has a concave portion as shown in
Light 1400 from a semiconductor light emitting chip 1200 in the semiconductor light emitting device 1000 is reflected from a boundary 1500 between an encapsulating member 1300 and outside. This reflected light 1400 can be reflected by a concave portion of the upper face 1111 of the bottom part 1110 of the frame 1100 for a semiconductor light emitting device in a dotted line and then escape from the semiconductor light emitting device 1000. In other words, light that might have been captured inside the semiconductor light emitting device 1000 when the upper face 1111 of the bottom part 1110 is flat can still escape from the semiconductor light emitting device 1000 as the upper face 1111 of the bottom part 1110 has at least one of convex and concave portions, and this will bring about an increased efficiency of light extraction. It is more desirable to have a concave portion on the upper face 1111 of the bottom part 1110 in terms of higher light extraction efficiency.
The following describes diverse exemplary embodiments of the present disclosure.
(1) A frame for a semiconductor light emitting device to receive a semiconductor light emitting chip, the frame comprising: a side wall; and a bottom part, which is connected to the side wall and has at least one hole for receiving a semiconductor light emitting chip.
(2) A frame for a semiconductor light emitting device, wherein a reflecting layer is formed at at least one of inner faces of the side wall of a frame and an upper face of the bottom part of a frame.
(3) A frame for a semiconductor light emitting device, wherein a reflecting layer is formed all over the upper face of the bottom part of a frame.
(4) A frame for a semiconductor light emitting device, wherein a reflecting layer is a metallic layer.
(5) A frame for a semiconductor light emitting device to receive a semiconductor light emitting chip, the frame comprising: a side wall; a bottom part, which is connected to the side wall and has at least one hole for receiving a semiconductor light emitting chip; and a bonding part provided at the lower face of the bottom part, the bonding part being located a distance away from the hole in the bottom part.
(6) A frame for a semiconductor light emitting device, wherein a bonding part is made of a metal.
(7) A frame for a semiconductor light emitting device, wherein a side wall have a height greater than length of a bottom part.
(8) A frame for a semiconductor light emitting device, wherein plural holes are formed, and barriers are arranged between the holes.
(9) A frame for a semiconductor light emitting device, wherein a hole has slanted lateral faces.
(10) A frame for a semiconductor light emitting device, wherein a side wall has a protruded portion.
(11) A frame for a semiconductor light emitting device to receive a semiconductor light emitting chip, the frame comprising: a side wall; a bottom part, which is connected to the side wall and has at least one hole for receiving a semiconductor light emitting chip; and at least one reinforcement member provided at the bottom part, which is arranged in a non-overlapping fashion with the hole in the bottom part.
(12) A frame for a semiconductor light emitting device, wherein a reinforcement member is located between the upper face and the lower face of the bottom part of a frame.
(13) A frame for a semiconductor light emitting device, wherein a reinforcement member is located at the lower face of the bottom part of a frame.
(14) A frame for a semiconductor light emitting device, wherein a reinforcement member comprises a protecting element.
(15) A frame for a semiconductor light emitting device, wherein a bottom part comprises a protecting element, and electrodes of the protecting element are placed on the reinforcement member in a shorted state.
(16) A frame for a semiconductor light emitting device, wherein the upper face of the bottom part of a frame has at least one of concave and convex portions.
According to the present disclosure, a frame for a semiconductor light emitting device can be obtained, in which the electrodes of a semiconductor light emitting chip being received are bonded directly to an external substrate.
Moreover, according to the present disclosure, a frame for a semiconductor light emitting device can be obtained, which does not require bonding between lead frames and a flip chip such that no light intensity from the flip chip may be lost due to the bonding between the lead frames and the flip chip.
Frame for a semiconductor light emitting device: 210, 310, 410, 510, 610, 710, 800, 910, 1100
Semiconductor light emitting chip: 150, 220, 320, 420, 520, 630, 720, 1200
Reinforcement member: 620
Number | Date | Country | Kind |
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10-2015-0161721 | Nov 2015 | KR | national |