LED module

Abstract

Light-emitting diode module, LED module, comprising: a carrier (100) containing a heat dissipation pad (101); a circuit board (300) spaced from the heat dissipation pad (101) on the carrier (100), the circuit board (300) including at least one pair of contact surfaces (311) and an electrical connection terminal (312) electrically connected to the at least one pair of contact surfaces (311); an LED device (200) comprising: a wiring board (210) having a lower surface (LS) and an upper surface (US) opposite each other, a lower wiring (211) on the lower surface (LS) of the wiring board (210) facing the heat dissipation pad (101), an upper wiring (212) on the upper surface (US) of the wiring board (210) which is electrically insulated from the lower wiring (211), at least one pair of contact structures (214) on one side of the upper wiring (212), at least one LED chip (250) mounted on another side of the upper wiring (212), at least one wavelength conversion layer (280) on the at least one LED chip (250), and a reflective structure (260) covering the upper surface (US) of the wiring board (210) such that at least a portion of both the at least one pair of contact structures (214) and the at least one wavelength conversion layer (280) is exposed; a bonding wire (BW) electrically connecting the at least one pair of contact surfaces (311) and the at least one pair of contact structures (214) to one another; and a conductive bump (110) between the heat dissipation pad (101) and the lower wiring (211).

Description

Background1. Area

[0001] The embodiments relate to a light-emitting diode (LED) module. 2. Description of related technology

[0002] To maintain the reliability and performance of LED modules, a heat dissipation structure can be used to efficiently dissipate heat generated by LED devices.

[0003] From the document DE 10 2015 107 864 A1 an optoelectronic device is known which comprises: a substrate having a first side, a second side opposite to the first side and an outer boundary; a light emitting unit formed on the first side; a first electrode electrically connected to the light emitting unit; a second electrode electrically connected to the light emitting unit; and a heat dissipation block formed between the first electrode and the second electrode and electrically insulated from the light emitting unit.

[0004] From the document US 2012 / 0 074 441 A1 a wafer-level light-emitting diode (LED) package and a method for its production are known.The LED package comprises a semiconductor stack having a semiconductor layer of a first conductivity type, an active layer, and a semiconductor layer of a second conductivity type; a plurality of contact holes disposed in the semiconductor layer of the second conductivity type and the active layer, the contact holes exposing the semiconductor layer of the first conductivity type; a first bump disposed on a first side of the semiconductor stack, the first bump electrically connected to the semiconductor layer of the first conductivity type via the plurality of contact holes; a second bump disposed on the first side of the semiconductor stack, the second bump electrically connected to the semiconductor layer of the second conductivity type; and a protective insulating layer covering a sidewall of the semiconductor stack.

[0005] An LED array chip with blue and red LEDs is known from US 2006 / 0 180 818 A1. The blue LEDs are formed by epitaxial growth on a SiC substrate. Bonding pads are formed on the SiC substrate in a wafer manufacturing process. The red LEDs are manufactured separately from the blue LEDs and formed on the bonding pads (46 and 48) using flip-chip technology. Summary

[0006] The embodiments may be implemented by providing a light-emitting diode (LED) module including: a carrier including a heat dissipation pad; a circuit board spaced from the heat dissipation pad on the carrier, the circuit board including at least one pair of contact pads and an electrical connection terminal electrically connected to the at least one pair of contact pads;an LED device comprising a wiring board having a lower surface and an upper surface opposite each other, lower wiring on the lower surface of the wiring board facing the heat dissipation pad, upper wiring on the upper surface of the wiring board electrically insulated from the lower wiring, at least one pair of contact structures on one side of the upper wiring, at least one LED chip mounted on another side of the upper wiring, at least one wavelength conversion layer on the at least one LED chip, and a reflective structure covering the upper surface of the wiring board such that at least a portion of both the at least one pair of contact structures and the at least one wavelength conversion layer is exposed;a bond wire electrically connecting the at least one pair of contact pads and the at least one pair of contact structures; and a conductive bump between the heat dissipation pad and the lower wiring.

[0007] The embodiments can be implemented by providing a light-emitting diode (LED) module including: a carrier including a heat dissipation pad; a circuit board spaced from the heat dissipation pad on the carrier and including a pair of contact surfaces; an LED device including a wiring board having a lower surface and an upper surface opposite each other, lower wiring on the lower surface of the wiring board facing the heat dissipation pad, upper wiring on the upper surface of the wiring board, a pair of contact structures on the upper wiring, a plurality of LED chips electrically connected to the pair of contact structures through the upper wiring, and a reflective structure covering the upper surface of the wiring board such that at least a portion of the pair of contact structures is exposed;a bonding wire electrically connecting the pair of contact pads and the pair of contact structures; and a conductive bump between the heat dissipation pad and the lower wiring.

[0008] The embodiments can be implemented by providing a light-emitting diode (LED) module including: a carrier including a heat dissipation pad; a circuit board spaced from the heat dissipation pad on the carrier and including a pair of contact surfaces; an LED device including a wiring board having a lower surface and an upper surface opposite each other, lower wiring on the lower surface of the wiring board facing the heat dissipation pad, upper wiring on the upper surface of the wiring board, a pair of contact structures on the upper wiring, a plurality of LED chips electrically connected to the pair of contact structures through the upper wiring, and a reflective structure covering the upper surface of the wiring board such that at least a portion of the pair of contact structures is exposed;a bonding wire electrically connecting the pair of contact pads and the pair of contact structures; and a conductive bump between the heat dissipation pad and the lower wiring, wherein the heat dissipation pad completely overlaps the LED device in a plan view. Short description of the drawings

[0009] The features will be apparent to a person skilled in the art from a detailed description of embodiments with reference to the accompanying drawings, in which: Fig. 1A is a perspective view of a light-emitting diode (LED) module according to one embodiment; Fig. 1B a side view of a right side of the LED module Fig. 1A is; Fig. 2 is a partially enlarged view of a modified example of an LED module according to an embodiment; Fig. 3 is a partially enlarged view of a modified example of an LED module according to an embodiment; Fig. 4 is a partially enlarged view of a modified example of an LED module according to an embodiment; Fig. 5A is a perspective view of an LED device applicable to an LED module; Fig. 5B is a cross-sectional view along line II' in Fig. 5A is; Fig. 5C a cross-sectional view along line II-II' in Fig. 5A is; Fig. 6A is a plan view of an upper surface of a wiring board applicable to an LED device; Fig. 6B is a bottom view of a lower surface of a wiring board applicable to an LED device; Fig. 7A and Fig. 7B are cross-sectional views of an LED chip applicable to an LED device; Fig. 8A to 8D are cross-sectional views of stages in a manufacturing process of an LED module according to an embodiment; and Fig. 9 is a cross-sectional view of a headlight to which an LED module according to an embodiment is applied as a light source. Detailed description

[0010] Fig. 1A is a perspective view of an LED module 10 according to one embodiment and Fig. 1B is a side view of a right side of the LED module of Fig. 1A.

[0011] Referring to Fig. 1A and Fig. 1B, according to one embodiment, the LED module 10 may include a carrier 100, an LED device 200, and a circuit board 300. In one implementation, the LED device 200 may be attached to the carrier 100 using a metal structure (e.g., a metal pad or a metal bump) instead of an adhesive resin, thereby improving heat dissipation efficiency through the carrier 100 and removing a residue protruding to the outside of the LED device 200 to interfere with aesthetics (e.g., an adhesive resin may leak from the LED device 200). In one implementation, misalignment of the LED device 200 (which might otherwise occur during a curing time of the adhesive resin) may be prevented, and a distance between the LED device 200 and the carrier 100 may be uniform.In one implementation, development accuracy can be improved, and typical deviation of the LED module 10 resulting from a development error or a process error (e.g., a difference in height from the carrier 100 to a light-emitting region EL of the LED device 200) can be minimized. In one implementation, this structure can also be applied to a device for attaching an electronic component (e.g., an integrated circuit chip, a transistor chip, or the like) to a separate carrier (e.g., a substrate, a heat sink, or the like) using an adhesive resin.

[0012] The carrier 100 may be a support structure on which the LED device 200 and the circuit board 300 are mounted, and may include elements for the LED module 10 to be coupled to a lighting device (e.g., a headlight). In one implementation, the carrier 100 may include a material with high thermal conductivity, e.g., copper (Cu), aluminum (Al), iron (Fe), nickel (Ni), silver (Ag), gold (Au), platinum (Pt), tin (Sn), lead (Pb), titanium (Ti), chromium (Cr), palladium (Pd), indium (In), zinc (Zn), carbon (C), or alloys thereof. The carrier 100 may include a heat dissipation pad 101 on which the LED device 200 is mounted. In one implementation, by mounting the LED device 200 on the heat dissipation pad 101 using surface mount technology (SMT), a heat dissipation path connected from the LED device 200 to the carrier 100 may be formed.The heat dissipation pad 101 may include a material having a thermal conductivity of approximately 300 W / mK or more. In one implementation, the heat dissipation pad 101 may include, for example, aluminum (Al), gold (Au), cobalt (Co), copper (Cu), nickel (Ni), lead (Pb), tantalum (Ta), tellurium (Te), titanium (Ti), tungsten (W), or alloys thereof. In one implementation, the heat dissipation pad 101 may further include a surface plating layer in contact with a conductive bump 110 (see the embodiments of FIG. Fig. 3 and Fig. 4).

[0013] In one implementation, the heat dissipation pad 101 may have a planar area on a plane (XY plane) smaller than that of the LED device 200 (or a wiring board 210), thereby completely overlapping the LED device 200 and restricting a spreading area of ​​the conductive bump 110. In one implementation, the conductive bump 110 may not protrude to the outside of the LED device 200 during a reflow process. In one implementation, the heat dissipation pad 101 may have a width W1 smaller than a width W4 of the wiring board 210 in a direction parallel to a bottom surface LS of the wiring board 210 (e.g., the X direction).

[0014] In one implementation, the characteristics of the LED module 10 can be maintained by forming a height H1 (e.g., in a vertical Z direction) from a top surface of the carrier 100 to the top surface of the heat dissipation pad 101 according to a structure such that they are constant. In one implementation, the height H1 from the top surface of the carrier 100 to the top surface of the heat dissipation pad 101 can be, for example, in a range of about 1 µm to about 30 µm, about 1 µm to about 20 µm, about 5 µm to about 30 µm, about 5 µm to about 20 µm, about 10 µm to about 30 µm, or about 10 µm to about 20 µm. In one implementation, the height H1 of the heat dissipation pad 101 can be varied variously according to a structure.

[0015] The LED device 200 may be on the heat dissipation pad 101 of the carrier 100 and may include the wiring board 210 and a reflective structure 260.

[0016] The wiring board 210 may have a bottom surface LS and a top surface US that are opposite to each other. At least one LED chip and a wavelength conversion layer 280 may be sequentially stacked on the top surface US of the wiring board 210, and at least one pair of contact structures 214 may be spaced therefrom on the top surface US of the wiring board 210. The pair of contact structures 214 may be connected by an upper wiring (see 212 in Fig. 5A) of the wiring board 210 may be electrically connected to an LED chip. The wiring board 210 may be, for example, a printed circuit board (PCB), such as a metal core PCB (MCPCB), a metal PCB (MPCB), a flexible PCB (FPCB), or the like, or a ceramic board.

[0017] A lower wiring 211 may be on the lower surface LS of the wiring board 210. The lower wiring 211 may be for surface mounting of the LED device 200 and may be electrically insulated from the LED chip. The lower wiring 211 may have a width W2 that is smaller than the width W4 of the wiring board 210 in the direction (e.g., the X-axis direction) parallel to the lower surface LS of the wiring board 210. In one implementation, the width W2 of the lower wiring 211 may be substantially the same as the width W1 of the heat dissipation pad 101. In one implementation, the lower wiring 211 may include a first surface plating layer 211PL that is in contact with the conductive bump 110. The lower wiring 211 may contain, for example, aluminum (Al), gold (Au), cobalt (Co), copper (Cu), nickel (Ni), lead (Pb), tantalum (Ta), tellurium (Te), titanium (Ti) or alloys thereof.The first surface plating layer 211PL may include, for example, tin (Sn), lead (Pb), nickel (Ni), or gold (Au). In one implementation, the height H2 of the lower wiring 211 may be similar to the height H1 of the heat dissipation pad 101 (e.g., as measured in the Z direction). The height H2 of the lower wiring 211 may be variously modified according to a structure. Components constituting the wiring board 210 are described with reference to FIG. Fig. 6A to 6C. As used herein, the terms "first," "second," and the like are for identification and distinction purposes only and are not intended to imply or require sequential inclusion (e.g., a third element and a fourth element may be described without implying or requiring the presence of a first element or a second element).

[0018] In one implementation, the LED device 200 may be mounted on a surface of the substrate 100 using the lower wiring 211 and the conductive bump 110 instead of an adhesive resin, so that a residue (e.g., adhesive resin leaking from the LED device 200) can be prevented from protruding to the outside of the LED device 200. In one implementation, the wiring board 210 may overlap the entire heat dissipation pad 101 on a plane (XY plane). The conductive bump 110 may be between the heat dissipation pad 101 and the lower wiring 211 and may be formed such that it does not protrude from or beyond an edge of the wiring board 210 on a plane (XY plane). In one implementation, the conductive bump 110 may have a width W3 equal to or smaller than the width W4 of the wiring board 210 in the direction (e.g.,the X-direction) parallel to the bottom surface LS of the wiring board 120. In one implementation, the conductive bump 110 may include a material having a thermal conductivity of approximately 10 W / mK or more. In one implementation, the conductive bump 110 may include tin (Sn), indium (In), bismuth (Bi), antimony (Sb), copper (Cu), silver (Ag), zinc (Zn), lead (Pb), or alloys thereof. In one implementation, the conductive bump 110 may assist in improving the heat dissipation effect between the LED device 200 and the carrier 100. For example, a height H3 of the conductive bump 110 (in the Z direction) may be in a range of about 1 µm to about 50 µm, about 1 µm to about 40 µm, about 1 µm to about 30 µm, or about 1 µm to about 20 µm. In one implementation, the height H3 of the conductive bump 110 may be varied variously according to a structure.

[0019] The reflective structure 260 may cover the upper surface US of the wiring board such that at least a portion of both the at least one wavelength conversion layer 280 stacked on at least one LED chip and at least one pair of contact structures 214 may be thereon. The reflective structure 260 may define the light-emitting region EL provided by the at least one wavelength conversion layer 280. The reflective structure 260 may include a resin body including a reflective powder. In one implementation, the resin body may include silicon or epoxy resin. The reflective powder may be a white ceramic powder or a metal powder. In one implementation, the ceramic powder may be, for example, TiO 2 , Al 2 O 3 , Nb 2 O 5 or ZnO. The metal powder may contain, for example, Al or Ag.

[0020] The circuit board 300 may be on the carrier 100 and spaced from the heat dissipation pad 101 and may include at least one pair of contact pads 311, an electrical connection terminal 312, and a wiring circuit 313. The circuit board 300 may be attached to the carrier 100 by an adhesive layer 102. The pair of contact pads 311 may each be electrically connected to the pair of contact structures 214 by a bonding wire BW. The pair of contact pads 311 may include, for example, aluminum (Al), gold (Au), cobalt (Co), copper (Cu), nickel (Ni), lead (Pb), tantalum (Ta), tellurium (Te), titanium (Ti), or alloys thereof. The electrical connection terminal 312 may be electrically connected to the at least one pair of contact pads 311 by the wiring circuit 313. A number of electrical connection terminals 312 may be equal to or greater than a number of the pair of contact surfaces 311.In one implementation, the electrical connection terminal 312 may include second electrical connection terminals 312b for passive elements 320 in addition to a pair of first electrical connection terminals 312a for input / output signal transmission of the LED device 200 to correspond to the pair of contact pads 311. The wiring circuit 313 may electrically connect the passive elements 320, the electrical connection terminal 312, and at least one pair of contact pads 311. The circuit board 300 may be a support board on which the passive elements 320 are mounted and may include a PCB, a ceramic board, a glass board, a ribbon wiring board, or the like. The passive elements 320 may include a capacitor element, a resistance element, or an inductance element. The passive elements 320 may form a driving circuit of the LED device 200 together with the wiring circuit 313.In one implementation, a test terminal TP for electrical testing of the driver circuit may be between the pair of first electrical connection terminals 312a and the pair of contact pads 311, each connected by the wiring circuit 313.

[0021] Fig. 2 is a partially enlarged view of a modified example of an LED module 10a according to an embodiment.

[0022] Referring to Fig. 2, the LED module 10a of the modified example has the same or similar characteristics as those described above with reference to Fig. 1A and Fig. 1B, except that the planar area of ​​the heat dissipation pad 101 may be smaller than that of the lower wiring 211. In one implementation, the lower wiring 211 may have a width W2 that is larger than a width W1 of the heat dissipation pad 101 in the direction (e.g., X direction) parallel to the bottom surface LS of the wiring board 210. In one implementation, the heat dissipation pad 101 may completely overlap the wiring board 210 in the vertical direction (Z direction). In one implementation, a wet area and a spreading area of ​​the conductive bump 110 may be limited to the inside of the wiring board 210 such that the conductive bump 110 may not protrude to the outside of the wiring board 210 on or beyond a plane (XY plane).

[0023] Fig. 3 is a partially enlarged view of a modified example of an LED module 10b according to an embodiment.

[0024] Referring to Fig. 3, the LED module 10b of the modified example has the same or similar characteristics as those described above with reference to Fig. 1A to 2, except that the heat dissipation pad 101 may include a second surface plating layer 101PL in contact with the conductive bump 110. In this modified example, the lower wiring 211 may include the first surface plating layer 211PL in contact (e.g., in direct contact) with the conductive bump 110, and the heat dissipation pad 101 may include the second surface plating layer 101PL in contact (e.g., in direct contact) with the conductive bump 110. The second surface plating layer 101PL may include a material that is the same as or similar to that of the first surface plating layer 211PL, e.g., tin (Sn), lead (Pb), nickel (Ni), or gold (Au).The second surface plating layer 101PL may be a single-layer or multi-layer metal layer that provides an upper surface of the heat dissipation pad 101. The second surface plating layer 101PL may confine a wet area of ​​the conductive bump 110 to the upper surface of the heat dissipation pad 101 and may help improve connection reliability between the heat dissipation pad 101 and the conductive bump 110.

[0025] Fig. 4 is a partially enlarged view of a modified example of an LED module 10c according to an embodiment.

[0026] Referring to Fig. 4, the LED module 10c of the modified example has the same or similar characteristics as those described above with reference to Fig. 1A to 2, except that the LED module 10c may include the second surface plating layer 101PL forming an upper surface and a side surface of the heat dissipation pad 101. In this modified example, the lower wiring 211 may include the first surface plating layer 211PL in contact with the conductive bump 110 (e.g., in direct contact), and the heat dissipation pad 101 may include the second surface plating layer 101PL in contact with the conductive bump 110 (e.g., in direct contact). The second surface plating layer 101PL may be a single-layer or multi-layer metal layer providing the upper surface and the side surface of the heat dissipation pad 101.The second surface plating layer 101PL can extend a wet area of ​​the conductive bump 110 to the side surface of the heat dissipation pad 101, thereby improving the connection reliability between the heat dissipation pad 101 and the conductive bump 110 and further enhancing the heat dissipation effect.

[0027] Fig. 5A is a perspective view of an LED device 200 applicable to an LED module, Fig. 5B is a cross-sectional view along line II' in Fig. 5A and Fig. Figure 5C is a cross-sectional view along line II-II' in Fig. 5A.

[0028] Referring to Fig. 5A to 5B, the LED device 200 may include the wiring board 210, the LED chip 250, the wavelength conversion layer 280, and the reflective structure 260.

[0029] The wiring board 210 may include the lower wiring 211 on its lower surface LS, an upper wiring 212 on its upper surface US, and at least one pair of contact structures 214 on one side of the upper wiring 212. At least one LED chip 250 may be mounted on the other side of the upper wiring 212. The wiring board 210 may be a package substrate, such as a PCB, a ceramic substrate, a glass substrate, or a ribbon wiring board.

[0030] The upper wiring 212 may include, for example, aluminum (Al), gold (Au), cobalt (Co), copper (Cu), nickel (Ni), lead (Pb), tantalum (Ta), tellurium (Te), titanium (Ti), or alloys thereof. The upper wiring 212 may be electrically isolated from the lower wiring 211 and may electrically connect at least one LED chip 250 and at least one pair of contact structures 214.

[0031] The at least one pair of contact structures 214 may be electrically connected to the at least one LED chip 250 through the top wiring 212 and may be exposed to the outside of the LED device 200 to provide an input / output terminal of a current for driving the LED chip 250. In one implementation, each of the at least one pair of contact structures 214 may include a metal pad portion 214P exposed on the top surface of the LED device 200. The at least one pair of contact structures 214 and the metal pad portion 214P may be formed from a metal material, e.g., aluminum (Al), tungsten (W), or molybdenum (Mo), or a semiconductor material, e.g., doped polysilicon.

[0032] The at least one LED chip 250 may be mounted on a surface, namely the upper surface US of the wiring board 210, and may be electrically connected to the at least one pair of contact structures 214 through the upper wiring 212. In one implementation, the at least one LED chip 250 may be electrically connected to wiring electrodes 212a and 212b of the upper wiring 212 through the metal bump 215. The metal bump 215 may contain, for example, tin (Sn), lead (Pb), nickel (Ni), or gold (Au). The at least one LED chip 250 may be provided as a plurality of LED chips 250, each having a first electrode 259a and a second electrode 259b. In one implementation, the plurality of LED chips 250 may be connected in series by the upper wiring 212 so that a current may flow through each of the first and second electrodes 259a and 259b in a forward direction.In one implementation, the plurality of LED chips 250 may be connected in parallel.

[0033] At least one wavelength conversion layer 280 may be stacked on each LED chip 250 to correspond to the at least one LED chip 250. The at least one wavelength conversion layer 280 may include at least one wavelength conversion material that converts a portion of light emitted from the LED chip 250 into light of a first wavelength different from an emission wavelength. The wavelength conversion layer 280 may, for example, be a resin layer in which a wavelength conversion material is dispersed, or may be a ceramic phosphor layer. The wavelength conversion material may be a phosphor or a quantum dot. In one implementation, the LED device 200 may be configured to emit white light.The LED chip 250 may emit blue light, and the wavelength conversion material may include a phosphor or a quantum dot that converts a portion of the blue light into yellow light, or may include a plurality of phosphors or quantum dots that convert a portion of the blue light into red and green light.

[0034] The reflective structure 260 may cover the upper surface US of the wiring board 210 such that at least a portion of both the at least one pair of contact structures 214 and the at least one wavelength conversion layer 280 is exposed. The reflective structure 260 may include a resin body containing a reflective powder. An upper surface of the reflective structure 260 may be coplanar with the upper surface of the at least one pair of contact structures 214 and the upper surface of the at least one wavelength conversion layer 280.

[0035] Fig. 6A is a plan view of an upper surface US of the wiring board 210 applicable to an LED device, and Fig. 6B is a bottom view of a lower surface LS of the wiring board 210 applicable to an LED device.

[0036] Referring to Fig. 6A and Fig. 6B, the wiring board 210 may have the upper surface US on which an upper wiring 212 is arranged and the lower surface LS on which a lower wiring 211 is arranged.

[0037] The upper wiring 212 may include first and second wiring electrodes 212a and 212b corresponding respectively to the first and second electrodes 259a and 259b of an LED chip (“250” in Fig. 5C), and at least one pair of landing electrodes 212Pa and 212Pb corresponding to the at least one pair of contact structures (“214” in Fig. 5A). In the upper wiring 212, at least one pair of landing electrodes 212Pa and 212Pb may intersect to connect to the first and second electrodes 259a and 259b of each of the LED chips (“250” in Fig. 5C) to be connected to the at least one LED chip (“250” in Fig. 5C) with a forward current.

[0038] The lower wiring 211 may be electrically insulated from the upper wiring 212 and may be connected to the heat dissipation pad 101 of the carrier (“100” in Fig. 1A) to provide a path for dissipating heat generated by the LED chip 250. In one implementation, the lower wiring 211 may have a plate shape covering at least a portion of the bottom surface LS of the wiring board 210 to maximize the heat dissipation effect. In one implementation, the lower wiring 211 may have two or more plate shapes that are separated from each other according to embodiments.

[0039] Fig. 7A and Fig. 7B are cross-sectional views of LED chips 250A and 250B applicable to an LED device.

[0040] Referring to Fig. 7A, the LED chip 250A may include a substrate 251 and a semiconductor stack S including a first conductivity type semiconductor layer 254, an active layer 255, and a second conductivity type semiconductor layer 256 sequentially stacked on the substrate 251. A buffer layer 252 may be between the substrate 251 and the first conductivity type semiconductor layer 254.

[0041] The substrate 251 may be an insulating substrate, e.g., sapphire. In one implementation, the substrate 251 may be a conductive substrate or a semiconductor substrate in addition to an insulating substrate. In one implementation, the substrate 251 may be made of SiC, Si, MgAl 2 O 4 , MgO, LiAlO 2 , LiGaO 2or GaN in addition to sapphire. An uneven portion C may be formed on an upper surface of the substrate 251. The uneven portion C can help improve the quality of a grown single crystal while improving the light extraction efficiency.

[0042] The buffer layer 252 can x Al y Ga 1-x-y N (0≤x≤1, 0≤y≤1). In one implementation, the buffer layer 252 may include GaN, AlN, AlGaN, or InGaN. In one implementation, a plurality of layers may be combined, or some compositions may be gradually changed to be used in the buffer layer 252.

[0043] The semiconductor layer 254 of a first conductivity type may include a nitride semiconductor comprising x Al y Ga 1-x-yN (0≤x<1, 0≤y<1, 0≤x+y<1) of an n-type, and an n-type impurity may be Si. In one implementation, the first conductivity type semiconductor layer 254 may include n-type GaN. The second conductivity type semiconductor layer 256 may include a nitride semiconductor layer containing In x Al y Ga 1-x-y N (0≤x<1, 0≤y<1, 0≤x+y<1) of a p-type, and a p-type impurity may be Mg. In one implementation, the second conductivity type semiconductor layer 256 may be implemented as a single-layer structure or may have a multi-layer structure with different compositions.

[0044] The active layer 255 may have a multiple quantum well (MQW) structure in which quantum well layers and quantum barrier layers are alternately stacked. In one implementation, the quantum well layer and the quantum barrier layer may x Al y Ga 1-x-yN (0≤x≤1, 0≤y≤1, 0≤x+y<1) with different compositions. In one implementation, the quantum well layer can be x Ga 1-x N (0 <x≤1) enthalten und die Quantenbarriereschicht kann GaN oder AlGaN enthalten. Die Dicke der Quantentopfschicht und der Quantenbarriereschicht kann jeweils im Bereich von z.B. ungefähr 1 nm bis ungefähr 50 nm sein. In einer Umsetzung kann die Aktivschicht 255 eine Einzelquantentopfstruktur aufweisen.

[0045] The first and second electrodes 259a and 259b may each be on the mesa-etched region of the first conductivity type semiconductor layer 254 and the second conductivity type semiconductor layer 256 to be positioned on the same surface. The first electrode 259a may include, for example, Ag, Ni, Al, Cr, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, or the like, and may be employed to have a single-layer structure or two or more layers. In one implementation, the second electrode 259b may be a transparent electrode, such as a transparent conductive oxide or a transparent conductive nitride, or may include graphene. The second electrode 259b may include, for example, Al, Au, Cr, Ni, Ti, or Sn.

[0046] Referring to Fig. 7B, an LED chip 250B may include a substrate 251 and a semiconductor stack S on the substrate 251, similar to the previous embodiment. The semiconductor stack S may include a buffer layer 252, a semiconductor layer 254 of a first conductivity type, an active layer 255, and a semiconductor layer 256 of a second conductivity type.

[0047] The LED chip 250B may include first and second electrode structures E1 and E2, respectively connected to the semiconductor layers 254 and 256 of first and second conductivity types. The first electrode structure E1 may include a connection electrode 258a, such as a conductive via, connected to the semiconductor layer 254 of first conductivity type through the semiconductor layer 256 of second conductivity type and the active layer 255, and a first electrode 259a connected to the connection electrode 258a. The connection electrode 258a may be surrounded by an insulating portion 257 to be electrically separated from the active layer 255 and the semiconductor layer 256 of second conductivity type. The connection electrode 258a may be on a region where the semiconductor stack S is etched.In one implementation, a number, shape, and pitch of the connecting electrode 258a or a contact area thereof with the semiconductor layer 254 of a first conductivity type may be appropriately designed to reduce contact resistance. In one implementation, the connecting electrodes 258a may be arranged to form rows and columns on the semiconductor stack S, thereby improving current flow. The second electrode structure E2 may include an ohmic contact layer 258b and a second electrode 259b on the semiconductor layer 256 of a second conductivity type.

[0048] The connection electrode 258a and the ohmic contact layer 258b may each include a single or multi-layer structure of a conductive material having ohmic properties with the semiconductor layer 254 and 256 of a first and second conductivity type, and may include, for example, Ag, Al, Ni, Cr, a transparent conductive oxide (TCO), or the like.

[0049] The first and second electrodes 259a and 259b may be connected to the connection electrode 258a and the ohmic contact layer 258b, respectively, to function as external terminals of the LED chip 250B. In one implementation, the first and second electrodes 259a and 259b may include Au, Ag, Al, Ti, W, Cu, Sn, Ni, Pt, Cr, NiSn, TiW, AuSn, or a eutectic metal thereof. The first and second electrode structures E1 and E2 may be arranged to face the same direction.

[0050] Fig. 8A to 8D are cross-sectional views of stages in a manufacturing process of an LED module according to an embodiment.

[0051] Referring to Fig. 8A, a plurality of LED chips 250 may be mounted on a surface of a strip substrate 210'. The strip substrate 210' may include a plurality of wiring boards 210. The plurality of wiring boards 210 may each include a lower wiring 211 on a lower surface and an upper wiring 212 on an upper surface. The plurality of LED chips 250 may be arranged such that the first and second electrodes 259a and 259b correspond to the first and second wiring electrodes 212a and 212b of the upper wiring 212. Preliminary contact bumps 215p may be pre-attached to the first and second wiring electrodes 212a and 212b of the upper wiring 212. In one implementation, a pair of contact structures ("214" in Fig. 5A) on the other side of the upper wiring 212.

[0052] Referring to Fig. 8B, a wavelength conversion layer 280 may be attached to each of the plurality of LED chips 250, and a reflective structure 260 surrounding the plurality of LED chips 250 and the wavelength conversion layer 280 may be formed. The wavelength conversion layer 280 may include at least one type of wavelength conversion material. The wavelength conversion layer 280 may be attached to the LED chip 250 by an adhesive member, such as epoxy. The reflective structure 260 may be formed by applying and curing a resin body containing a reflective powder. In one implementation, the reflective structure 260 may be formed from silicon containing a TiO 2 -powder contains.

[0053] Referring to Fig. 8C, the plurality of LED devices 200 may be separated by cutting the strip substrate 210' and the reflective structure 260. The strip substrate 210' and the reflective structure 260 may be cut using a blade BL or may also be cut by a laser according to one embodiment.

[0054] Referring to Fig. 8D, the LED device 200 and the circuit board 300 may be attached to the carrier 100. The LED device 200 may be attached to the heat dissipation pad 101 of the carrier 100. A preliminary conductive bump 110p may be formed on the heat dissipation pad 101. The preliminary conductive bump 110p may be cured by a reflow process to form the conductive bump 110. Fig. 1B. In one implementation, the LED device 200 and the carrier 100 may be connected to the heat dissipation pad 101, the bottom wiring 211 and the conductive bump (“110” in Fig. 1B), thereby improving the heat dissipation and structural properties of the LED module. The circuit board 300 may be attached to the adhesive layer 102 of the carrier 100 in a state in which the passive elements 320 are mounted thereon. The adhesive layer 102 may include a layer or tape containing an adhesive resin. Subsequently, the pair of contact surfaces 311 of the circuit board 300 and the pair of contact structures 214 of the LED device 200 may be bonded using a bonding wire (“BW” in Fig. 1A) can be connected.

[0055] Fig. 9 is a cross-sectional view of a headlight 1000 to which an LED module according to an embodiment is applied as a light source.

[0056] Referring to Fig. 9, the headlight 1000 may be used as a vehicle light or the like and may include a light source 1001, a reflector 1005, and a lens cover 1004, and the lens cover 1004 may include a waveguide 1003 and a lens 1002. The light source 1001 may have the configuration described above with reference to Fig. 1A to 7B contain the LED modules 10, 10a, 10b and 10c.

[0057] The headlight 1000 may further include a heat dissipator 1012 that dissipates heat generated by the light source 1001 to the outside, and the heat dissipator 1012 may include a heat sink 1010 and a cooling fan 1011 to effectively dissipate heat. In addition, the headlight 1000 may further include a housing 1009 for attaching and supporting the heat dissipator 1012 and the reflector 1005, and the housing 1009 may include a center hole 1008 in a surface of a body portion thereof to facilitate coupling and mounting the heat dissipator 1012 therein. The housing 1009 may include a front hole 1007 for attaching the reflector 1005 to an upper side of the light source 1001 on the other surface, which is integrally connected to one surface and inclined in a perpendicular direction.Accordingly, a front side may be open through the reflector 1005, and the reflector 1005 may be fixed to the housing 1009 such that the open front side corresponds to the front hole 1007, and light reflected by the reflector 1005 may exit to the outside through the front hole 1007.

[0058] In summary and in retrospect, in the case of an LED module in which a plurality of LED devices are embedded, heat generated by the plurality of LED devices could cause a deterioration in the performance of the LED module.

[0059] According to embodiments, an LED module with improved heat dissipation properties can be provided.

Claims

[1] Light-emitting diode module, LED module, comprising: a carrier (100) containing a heat dissipation pad (101); a circuit board (300) spaced from the heat dissipation pad (101) on the carrier (100), the circuit board (300) including at least one pair of contact surfaces (311) and an electrical connection terminal (312) electrically connected to the at least one pair of contact surfaces (311); an LED device (200) comprising: a wiring board (210) having a lower surface (LS) and an upper surface (US) opposite each other, a lower wiring (211) on the lower surface (LS) of the wiring board (210) facing the heat dissipation pad (101), an upper wiring (212) on the upper surface (US) of the wiring board (210) which is electrically insulated from the lower wiring (211), at least one pair of contact structures (214) on one side of the upper wiring (212), at least one LED chip (250) mounted on another side of the upper wiring (212), at least one wavelength conversion layer (280) on the at least one LED chip (250), and a reflective structure (260) covering the upper surface (US) of the wiring board (210) such that at least a portion of both the at least one pair of contact structures (214) and the at least one wavelength conversion layer (280) is exposed; a bonding wire (BW) electrically connecting the at least one pair of contact surfaces (311) and the at least one pair of contact structures (214) to one another; and a conductive bump (110) between the heat dissipation pad (101) and the lower wiring (211). [2] The LED module according to claim 1, wherein the heat dissipation pad (101) has a width (W1) smaller than a width (W4) of the wiring board (210) in a direction parallel to the bottom surface (LS) of the wiring board (210). [3] The LED module according to claim 1 or 2, wherein the conductive bump (110) has a width (W3) equal to or smaller than a width (W4) of the wiring board (210) in a direction parallel to the lower surface (LS) of the wiring board (210). [4] The LED module according to any one of claims 1 to 3, wherein the conductive bump (110) does not protrude beyond an edge of the wiring board (210) in a plan view. [5] The LED module according to any one of claims 1 to 4, wherein the conductive bump (110) contains tin, Sn, indium, In, bismuth, Bi, antimony, Sb, copper, Cu, silver, Ag, zinc, Zn, lead, Pb, or an alloy thereof. [6] LED module according to one of claims 1 to 5, wherein the heat dissipation pad (101) contains copper, Cu, or an alloy of copper, Cu. [7] LED module according to one of claims 1 to 6, wherein: the lower wiring (211) includes a surface plating layer (211PL) in contact with the conductive bump (110), and the surface plating layer (211PL) contains tin, Sn, lead, Pb, nickel, Ni, or gold, Au. [8] Light-emitting diodes, LED, module, comprising: a carrier (100) containing a heat dissipation pad (101); a circuit board (300) spaced from the heat dissipation pad (101) on the carrier (100) and including a pair of contact surfaces (311); an LED device (200) comprising: a wiring board (210) having a lower surface (LS) and an upper surface (US) opposite each other, a lower wiring (211) on the lower surface (LS) of the wiring board (210) facing the heat dissipation pad (101), an upper wiring (212) on the upper surface (US) of the wiring board (210), a pair of contact structures (214) on the upper wiring (212), a plurality of LED chips (250) electrically connected to the pair of contact structures (214) by the upper wiring (212), and a reflective structure (260) covering the upper surface (US) of the wiring board (210) such that at least a portion of the pair of contact structures (214) is exposed; a bonding wire (BW) electrically connecting the pair of contact surfaces (311) and the pair of contact structures (214) to each other; and a conductive bump (110) between the heat dissipation pad (101) and the lower wiring (211). [9] The LED module according to claim 8, wherein the plurality of LED chips (250) are connected in series. [10] Light-emitting diode module, LED module, comprising: a carrier (100) containing a heat dissipation pad (101); a circuit board (300) spaced from the heat dissipation pad (101) on the carrier (100) and including a pair of contact surfaces (311); an LED device (200) comprising: a wiring board (210) having a lower surface (LS) and an upper surface (US) opposite each other, a lower wiring (211) on the lower surface (LS) of the wiring board (210) facing the heat dissipation pad (101), an upper wiring (212) on the upper surface (US) of the wiring board (210), a pair of contact structures (214) on the upper wiring (212), a plurality of LED chips (250) electrically connected to the pair of contact structures (214) by the upper wiring (212), and a reflective structure (260) covering the upper surface (US) of the wiring board (210) such that at least a portion of the pair of contact structures (214) is exposed; a bonding wire (BW) electrically connecting the pair of contact surfaces (311) and the pair of contact structures (214); and a conductive contact bump (110) between the heat dissipation pad (101) and the lower wiring (211), wherein the heat dissipation pad (101) completely overlaps the LED device (200) in a plan view.

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