LED chip electrode structure and LED chip

Abstract

The invention relates to the technical field of semiconductors, and particularly discloses an LED chip electrode structure and an LED chip, the LED chip electrode structure comprises an ohmic contact layer, a reflecting layer, a coating layer or an isolating layer, a conducting layer, a blocking layer and a wire bonding layer which are sequentially arranged along the light emitting direction of the LED chip, the conducting layer is a Cu layer, the wire bonding layer is an Au layer, and the coating layer or the isolating layer is a metal layer. The crystal structure of the barrier layer is different from the crystal structures of the conductive layer and the routing layer. The ohmic contact layer, the reflecting layer, the coating layer or the isolating layer, the conducting layer, the blocking layer and the routing layer are matched with one another, so that the thickness of the routing layer of the electrode structure can be reduced, the dosage of Au is reduced, the cost is reduced, meanwhile, the problem of high chip voltage caused by Au thinning can be avoided, the electrode structure is applied to an LED chip, and the service life of the LED chip is prolonged. The current conductivity of the LED chip can be effectively improved, and the material cost of the chip is reduced.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to an LED chip electrode structure and an LED chip. Background Art

[0002] LED (Light Emitting Diode) is a semiconductor light-emitting device that can convert electrical energy into light energy. With the development and progress of LED chip manufacturing technology, it has gradually become a new mainstream lighting source after incandescent lamps and fluorescent lamps. It has the advantages of small size, fast response, long life, environmental protection and energy saving, and is widely used in lighting, display screens and other fields.

[0003] The mainstream chips used in lighting fixtures on the market are still regular LED chips, which are connected to the power supply through bonding. The electrodes of regular LED chips are located on the light-emitting surface of the chip, and the electrodes include P-type electrodes and N-type electrodes, which have the same materials and structures. Existing electrodes are generally composed of an ohmic contact layer, a reflective layer, a coating layer, and a bonding layer, wherein the reflective layer is generally metal Al, and the bonding layer is generally inert and highly conductive metal Au.

[0004] In order to improve the current conductivity of the entire chip and thus reduce the chip voltage, the wire bonding layer metal Au is generally thicker, with a thickness of 1μm to 3μm, which causes a waste of precious metal Au and increases the cost of chip materials. If Au is thinned, it will lead to high voltage problems. At the same time, the coating layer also contains precious metal Pt, which further increases the cost of the chip. Summary of the invention

[0005] The purpose of the present invention is to provide an LED chip electrode structure and an LED chip in view of the existing technical status.

[0006] The electrode structure of the present invention cooperates with each other among the ohmic contact layer, the reflective layer, the coating layer or the insulating layer, the conductive layer, the barrier layer and the bonding layer, so that the thickness of the bonding layer (Au layer) of the electrode structure can be thinned, the amount of Au used can be reduced, and the cost can be reduced. At the same time, the problem of high chip voltage caused by thinning Au can be avoided. The electrode structure is applied to the LED chip, which can effectively improve the current conductivity of the LED chip and reduce the chip material cost.

[0007] In order to achieve the above object, the present invention adopts the following technical scheme:

[0008] The present invention provides an electrode structure of an LED chip, comprising an ohmic contact layer, a reflective layer, a coating layer or an insulating layer, a conductive layer, a barrier layer and a bonding layer arranged in sequence along the light emitting direction of the LED chip.

[0009] The conductive layer is a Cu layer, the bonding layer is an Au layer, and the crystal structure of the barrier layer is different from the crystal structures of the conductive layer and the bonding layer.

[0010] In some embodiments, the thickness of the bonding layer is less than 1 μm, and the thickness of the conductive layer and the thickness of the bonding layer are greater than or equal to 1 μm.

[0011] In some embodiments, the electrode structure includes a P-type electrode and an N-type electrode, and the P-type electrode and the N-type electrode both include an electrode pad and an electrode strip, wherein T min =13.5 / D, where T min is the minimum thickness of the bonding layer, in μm; D is the diameter or width of the electrode pad, in μm, and D is 20 μm to 150 μm.

[0012] In some embodiments, the thickness of the conductive layer is 0.3 μm to 4 μm.

[0013] In some embodiments, the barrier layer is any one of a Cr layer and a Ti layer, or is formed by periodically alternating layers of a Cr layer and a Ti layer.

[0014] And / or, the thickness of the barrier layer is 50nm to 300nm.

[0015] In some embodiments, a crystal structure of the isolation layer is different from crystal structures of the reflective layer and the conductive layer.

[0016] In some embodiments, the insulating layer is any one of a Cr layer and a Ti layer, or is formed by periodically alternating stacking of a Cr layer and a Ti layer.

[0017] And / or, the thickness of the insulating layer is 80nm to 500nm.

[0018] In some embodiments, the coating layer is formed by periodically alternating any one or more non-precious metal layers of Cr layer, Ti layer, Ni layer and Pt layer.

[0019] And / or, the coating layer has a thickness of 100 nm to 1000 nm.

[0020] In some embodiments, the reflective layer is an Al layer, and the thickness of the reflective layer is 50 nm to 300 nm;

[0021] And / or, the ohmic contact layer is any one of a Cr layer, a Ti layer, and a Ni layer, and the thickness of the ohmic contact layer is

[0022] The present invention also provides an LED chip, comprising the above-mentioned electrode structure.

[0023] The beneficial effects of the present invention are:

[0024] In the present invention, a coating layer (or insulating layer), a conductive layer, and a barrier layer are introduced between the reflective layer and the bonding layer of the electrode structure. Specifically, on the basis of using the Au layer as the bonding layer, a cheaper and more conductive Cu layer is introduced as the conductive layer to replace part of the bonding layer of the traditional structure, and a barrier layer with a crystal structure different from the above two is introduced between the conductive layer and the bonding layer to avoid the formation of a eutectic alloy between the conductive layer and the bonding layer, which leads to a decrease in conductivity and affects the bonding. A coating layer (or insulating layer) is introduced between the conductive layer and the reflective layer to avoid the mutual dissolution of the conductive layer and the reflective layer, which leads to a decrease in conductivity. Therefore, through the mutual cooperation among the ohmic contact layer, the reflective layer, the coating layer or insulating layer, the conductive layer, the barrier layer and the bonding layer, the thickness of the bonding layer (Au layer) of the electrode structure can be reduced, the amount of Au used is reduced, the cost is reduced, and at the same time, the problem of high chip voltage caused by thinning Au can be avoided. The electrode structure is applied to the LED chip, which can effectively improve the current conductivity of the LED chip and reduce the chip material cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a longitudinal cross-sectional view of an embodiment of an electrode structure of an LED chip of the present invention.

[0026] Figure 2 It is a longitudinal cross-sectional view of another embodiment of an electrode structure of an LED chip of the present invention.

[0027] Figure 3 It is a top view of the electrode structure of the present invention disposed on an LED chip. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in further detail below.

[0029] See also Figure 1 to Figure 2 As shown, the present invention provides an electrode structure of an LED chip, comprising an ohmic contact layer 2, a reflective layer 3, a coating layer 41 or an insulating layer 42, a conductive layer 5, a barrier layer 6 and a bonding layer 7, which are sequentially arranged along the light emitting direction of the LED chip.

[0030] The conductive layer 5 is a Cu layer, the bonding layer 7 is an Au layer, and the crystal structure of the barrier layer 6 is different from the crystal structures of the conductive layer 5 and the bonding layer 7 .

[0031] In a first embodiment, see Figure 1As shown, the electrode structure includes an ohmic contact layer 2, a reflective layer 3, a cladding layer 41, a conductive layer 5, a barrier layer 6 and a bonding layer 7 which are sequentially arranged along the light emitting direction of the LED chip.

[0032] In a second embodiment, see Figure 2 As shown, the electrode structure includes an ohmic contact layer 2, a reflective layer 3, an insulating layer 42, a conductive layer 5, a barrier layer 6 and a bonding layer 7 which are sequentially arranged along the light emitting direction of the LED chip.

[0033] In the present invention, a coating layer 41 (or an insulating layer 42), a conductive layer 5, and a barrier layer 6 are introduced between the reflective layer 3 and the bonding layer 7 of the electrode structure. On the basis of using the Au layer as the bonding layer 7, a Cu layer which is cheaper and has good conductivity is introduced as the conductive layer 5 to replace part of the bonding layer 7 of the traditional structure, and a barrier layer 6 having a crystal structure different from the above two is introduced between the conductive layer 5 and the bonding layer 7 to avoid the problems such as the decrease of conductivity, the increase of voltage, and the influence on bonding caused by the formation of a eutectic alloy between the conductive layer 5 and the bonding layer 7. The coating layer 41 (or insulating layer 42) is inserted to prevent the conductive layer 5 and the reflective layer 3 from dissolving each other and causing the conductive performance to decrease. Therefore, through the mutual cooperation among the ohmic contact layer 2, the reflective layer 3, the coating layer 41 or the insulating layer 42, the conductive layer 5, the barrier layer 6 and the bonding layer 7, the thickness of the bonding layer 7 (Au layer) of the electrode structure can be thinned, the amount of Au is reduced, the cost is reduced, and at the same time, the problem of high chip voltage caused by thinning Au can be avoided. The electrode structure is applied to the LED chip, which can effectively improve the current conductivity of the chip and reduce the chip material cost.

[0034] In some embodiments, the thickness of the bonding layer 7 is less than 1 μm, and the thickness of the conductive layer 5 and the thickness of the bonding layer 7 are greater than or equal to 1 μm.

[0035] The electrode structure of the present invention ensures that the thickness of the bonding layer 7 is reduced without causing the problem of high chip voltage due to thinning Au through the mutual cooperation among the ohmic contact layer 2, the reflective layer 3, the coating layer 41 or the insulating layer 42, the conductive layer 5, the barrier layer 6 and the bonding layer 7. On this basis, the thickness of the bonding layer 7 is thinned to less than 1μm, the amount of Au is reduced, the cost is reduced, and the thickness of the conductive layer 5 and the thickness of the bonding layer 7 are controlled to be greater than or equal to 1μm, ensuring that the two have sufficient thickness as a whole, further reducing the voltage, and ensuring that the chip has a lower voltage and lower material cost.

[0036] In some embodiments, see Figure 3 As shown, the electrode structure includes a P-type electrode 1A and an N-type electrode 1B, and the P-type electrode 1A and the N-type electrode 1B both include an electrode pad and an electrode strip, wherein T min=13.5 / D, where T min is the minimum thickness of the bonding layer 7, in μm; D is the diameter or width of the electrode pad, in μm, and D is 20 μm to 150 μm.

[0037] For details, see Figure 3 As shown, the P-type electrode 1A includes a P-type electrode pad 11A and a P-type electrode strip 12A, and the N-type electrode 1B includes an N-type electrode pad 11B and an N-type electrode strip 12B.

[0038] Specifically, when the cross-sectional shape of the electrode pad is a circular or quasi-circular structure, D is the diameter of the electrode pad.

[0039] When the cross-sectional shape of the electrode pad is a rectangle or a quasi-rectangular structure, D is the width of the electrode pad. Preferably, D is the maximum width of the electrode pad.

[0040] The inventor has conducted experiments and found that when T min =13.5 / D, the thickness of the bonding layer 7 can reach the thinnest thickness on the basis of meeting the bonding requirements, thereby effectively reducing the material cost.

[0041] In some embodiments, the thickness of the conductive layer 5 is 0.3 μm to 4 μm.

[0042] Illustratively, the thickness of the conductive layer 5 is 0.3 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm or 4 μm, but is not limited thereto.

[0043] Ensure that the conductive layer has sufficient thickness so that it can replace part of the wiring layer, effectively reduce the voltage and keep the cost under control. When used in chips, it can have both good current conductivity and low cost.

[0044] In some embodiments, the barrier layer 6 is any one of a Cr layer and a Ti layer, or is formed by periodically alternating stacking of a Cr layer and a Ti layer.

[0045] And / or, the thickness of the barrier layer 6 is 50 nm to 300 nm.

[0046] Illustratively, the thickness of the barrier layer 6 is 50 nm, 80 nm, 100 nm, 120 nm, 150 nm, 180 nm, 200 nm, 250 nm, 280 nm or 300 nm, but is not limited thereto.

[0047] Since the barrier layer 6 has a different crystal structure from the conductive layer 5 and the bonding layer 7, it can prevent the conductive layer 5 and the bonding layer 7 from forming an alloy, thereby avoiding problems such as decreased conductivity, increased voltage, and impact on bonding caused by the formation of an alloy between the conductive layer 5 and the bonding layer 7.

[0048] The thickness of the barrier layer 6 should not be too low, otherwise it is difficult to effectively prevent the conductive layer 5 and the bonding layer 7 from forming an alloy. The thickness of the barrier layer 6 should not be too thick, otherwise it is easy to cause the chip voltage to increase and increase unnecessary material costs.

[0049] In some embodiments, the crystal structure of the isolation layer 42 is different from the crystal structures of the reflective layer 3 and the conductive layer 5 .

[0050] By providing an insulating layer 42 having a crystal structure different from that of the reflective layer 3 and the conductive layer 5, the reflective layer 3 and the conductive layer 5 are prevented from dissolving into each other, thereby effectively avoiding problems such as voltage increase and conductivity decrease caused by the dissolution of the reflective layer 3 and the conductive layer 5.

[0051] In some embodiments, the insulating layer 42 is any one of a Cr layer and a Ti layer, or is formed by periodically alternating stacking of a Cr layer and a Ti layer.

[0052] And / or, the thickness of the insulating layer 42 is 80 nm to 500 nm.

[0053] Exemplarily, the thickness of the insulating layer 42 is 80 nm, 100 nm, 120 nm, 150 nm, 180 nm, 200 nm, 220 nm, 250 nm, 280 nm, 300 nm, 330 nm, 350 nm, 380 nm, 400 nm, 420 nm, 450 nm, 480 nm or 500 nm, but is not limited thereto.

[0054] Since the crystal structure of the barrier layer 6 is different from that of the conductive layer 5 and the reflective layer 3, it is possible to prevent the conductive layer 5 and the reflective layer 3 from diffusing and dissolving each other, and to avoid problems such as decreased conductivity, increased voltage, and impact on wire bonding caused by the formation of an alloy between the conductive layer 5 and the reflective layer 3. Compared with the solution of setting a coating layer 41 between the conductive layer 5 and the reflective layer 3, the barrier layer 6 does not need to use the precious metal Pt, which can further reduce material costs.

[0055] The thickness of the barrier layer 6 should not be too low, otherwise it is difficult to effectively prevent the conductive layer 5 and the reflective layer 3 from forming an alloy. The thickness of the barrier layer 6 should not be too thick, otherwise it is easy to cause the chip voltage to increase and increase unnecessary material costs.

[0056] Among them, the insulating layer 42 can be a Cr layer or a Ti layer or a periodic structure formed by periodically alternating Cr layers and Ti layers. When the insulating layer 42 is formed by periodically alternating Cr layers and Ti layers, the period of the insulating layer 42 can be 1, 2 or 3, but is not limited to this. For example, the insulating layer 42 can be Cr / Ti, Cr / Ti / Cr / Ti, Cr / Ti / Cr / Ti / Cr / Ti.

[0057] In some embodiments, the coating layer 41 is formed by periodically alternating any one or more non-precious metal layers of Cr layer, Ti layer, Ni layer and Pt layer.

[0058] And / or, the coating layer 41 has a thickness of 100 nm to 1000 nm.

[0059] Exemplarily, the coating layer 41 may be Cr / Pt, Cr / Pt / Cr / Pt, Ti / Pt, Ti / Pt / Ti / Pt, Cr / Ti / Pt, Cr / Ti / Pt / Cr / Ti / Pt, Cr / Ti / Ni / Pt, Cr / Ti / Ni / Pt / Cr / Ti / Ni / Pt, Ni / Pt, Ni / Pt / Ni / Pt, Ni / Ti / Pt or Ni / Ti / Pt / Ni / Ti / Pt, Ti / Ni / Pt / Ni / Pt / Ti, Ti / Ni / Pt / Ni / Pt, etc., but not limited thereto.

[0060] Illustratively, the thickness of the coating layer 41 is 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, 850 nm, 900 nm, 950 nm or 1000 nm, but is not limited thereto.

[0061] The coating layer 41 can cover the reflective layer 3 so that the reflective layer 3 will not dissolve with the conductive layer 5, thereby avoiding problems such as decreased conductivity and increased voltage caused by the mutual dissolution of the reflective layer 3 and the conductive layer 5. The coating layer 41 is formed by periodically alternating stacking of any one or more non-precious metal layers of Cr layer, Ti layer, and Ni layer and Pt layer. By introducing Pt, the conductive performance and long-term stability can be improved while reducing the amount of Pt used and reducing material costs.

[0062] In some embodiments, the reflective layer 3 is an Al layer, and the thickness of the reflective layer 3 is 50 nm to 300 nm.

[0063] Exemplarily, the thickness of the reflective layer 3 is 50 nm, 80 nm, 100 nm, 120 nm, 150 nm, 180 nm, 200 nm, 220 nm, 250 nm, 280 nm or 300 nm, but is not limited thereto.

[0064] The reflective layer 3 should not be too thin, otherwise the reflective effect will be reduced and the chip luminous efficiency will be affected. The reflective layer 3 should not be too thick, otherwise the conductivity will be affected and the chip voltage will be increased.

[0065] In some embodiments, the ohmic contact layer 2 is any one of a Cr layer, a Ti layer, and a Ni layer, and the thickness of the ohmic contact layer 2 is

[0066] Exemplarily, the thickness of the ohmic contact layer 2 is or But it is not limited to this.

[0067] The present invention also provides an LED chip, comprising the above-mentioned electrode structure.

[0068] The LED chip is a normal-mounted LED chip, and the electrode structure is arranged on the light-emitting surface of the chip.

[0069] In some embodiments, the electrode structure is fabricated by photolithography and metal coating equipment.

[0070] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0071] Example 1

[0072] This embodiment discloses an electrode structure of an LED chip, comprising an ohmic contact layer, a reflective layer, an insulating layer, a conductive layer, a barrier layer and a bonding layer arranged in sequence along the light emitting direction of the LED chip.

[0073] The conductive layer is a Cu layer, the bonding layer is an Au layer, and the crystal structure of the barrier layer is different from the crystal structures of the conductive layer and the bonding layer.

[0074] The thickness of the bonding layer is less than 1 μm, and the thickness of the conductive layer and the thickness of the bonding layer are greater than or equal to 1 μm.

[0075] Wherein, the thickness of the conductive layer is The thickness of the bonding layer is

[0076] The electrode structure includes a P-type electrode and an N-type electrode, and both the P-type electrode and the N-type electrode include an electrode pad and an electrode strip, wherein the diameter of the electrode pad is 60 μm.

[0077] Wherein, the barrier layer is a Ti layer, and the thickness of the barrier layer is

[0078] Wherein, the coating layer is Ti / Ni / Pt / Ni / Pt / Ti layer, and the thickness of each layer is

[0079] Wherein, the reflective layer is an Al layer, and the thickness of the reflective layer is

[0080] Wherein, the ohmic contact layer is a Cr layer, and the thickness of the ohmic contact layer is

[0081] This embodiment also discloses an LED chip, comprising the above-mentioned electrode structure.

[0082] The LED chip is a normal-mounted LED chip, and the electrode structure is arranged on the light-emitting surface of the chip.

[0083] Example 2

[0084] This embodiment discloses an electrode structure of an LED chip, comprising an ohmic contact layer, a reflective layer, an insulating layer, a conductive layer, a barrier layer and a bonding layer arranged in sequence along the light emitting direction of the LED chip.

[0085] The conductive layer is a Cu layer, the bonding layer is an Au layer, and the crystal structure of the barrier layer is different from the crystal structures of the conductive layer and the bonding layer.

[0086] The thickness of the bonding layer is less than 1 μm, and the thickness of the conductive layer and the thickness of the bonding layer are greater than or equal to 1 μm.

[0087] Wherein, the thickness of the conductive layer is The thickness of the bonding layer is

[0088] The electrode structure includes a P-type electrode and an N-type electrode, and both the P-type electrode and the N-type electrode include an electrode pad and an electrode strip, wherein the diameter of the electrode pad is 60 μm.

[0089] Wherein, the barrier layer is a Ti layer, and the thickness of the barrier layer is

[0090] Wherein, the coating layer is Ti / Ni / Pt / Ni / Pt / Ti layer, and the thickness of each layer is

[0091] Wherein, the reflective layer is an Al layer, and the thickness of the reflective layer is

[0092] Wherein, the ohmic contact layer is a Cr layer, and the thickness of the ohmic contact layer is

[0093] This embodiment also discloses an LED chip, comprising the above-mentioned electrode structure.

[0094] The LED chip is a normal-mounted LED chip, and the electrode structure is arranged on the light-emitting surface of the chip.

[0095] Example 3

[0096] This embodiment discloses an electrode structure of an LED chip, comprising an ohmic contact layer, a reflective layer, an insulating layer, a conductive layer, a barrier layer and a bonding layer arranged in sequence along the light emitting direction of the LED chip.

[0097] The conductive layer is a Cu layer, the bonding layer is an Au layer, and the crystal structure of the barrier layer is different from the crystal structures of the conductive layer and the bonding layer.

[0098] The thickness of the bonding layer is less than 1 μm, and the thickness of the conductive layer and the thickness of the bonding layer are greater than or equal to 1 μm.

[0099] Wherein, the thickness of the conductive layer is The thickness of the bonding layer is

[0100] The electrode structure includes a P-type electrode and an N-type electrode, and both the P-type electrode and the N-type electrode include an electrode pad and an electrode strip, wherein the diameter of the electrode pad is 60 μm.

[0101] Wherein, the barrier layer is a Ti layer, and the thickness of the barrier layer is

[0102] Wherein, the coating layer is Ti / Ni / Pt / Ni / Pt / Ti layer, and the thickness of each layer is

[0103] Wherein, the reflective layer is an Al layer, and the thickness of the reflective layer is

[0104] Wherein, the ohmic contact layer is a Cr layer, and the thickness of the ohmic contact layer is

[0105] This embodiment also discloses an LED chip, comprising the above-mentioned electrode structure.

[0106] The LED chip is a normal-mounted LED chip, and the electrode structure is arranged on the light-emitting surface of the chip.

[0107] Example 4

[0108] This embodiment discloses an electrode structure of an LED chip, comprising an ohmic contact layer, a reflective layer, an insulating layer, a conductive layer, a barrier layer and a bonding layer arranged in sequence along the light emitting direction of the LED chip.

[0109] The conductive layer is a Cu layer, the bonding layer is an Au layer, and the crystal structure of the barrier layer is different from the crystal structures of the conductive layer and the bonding layer.

[0110] The thickness of the bonding layer is less than 1 μm, and the thickness of the conductive layer and the thickness of the bonding layer are greater than or equal to 1 μm.

[0111] Wherein, the thickness of the conductive layer is The thickness of the bonding layer is

[0112] The electrode structure includes a P-type electrode and an N-type electrode, and both the P-type electrode and the N-type electrode include an electrode pad and an electrode strip, wherein the diameter of the electrode pad is 60 μm.

[0113] Wherein, the barrier layer is a Ti / Gr layer, and the thickness of each layer is

[0114] The crystal structure of the insulating layer is different from the crystal structures of the reflective layer and the conductive layer.

[0115] Wherein, the insulating layer is a Ti / Gr layer, and the thickness of each layer is

[0116] Wherein, the reflective layer is an Al layer, and the thickness of the reflective layer is

[0117] Wherein, the ohmic contact layer is a Cr layer, and the thickness of the ohmic contact layer is

[0118] This embodiment also discloses an LED chip, comprising the above-mentioned electrode structure.

[0119] The LED chip is a normal-mounted LED chip, and the electrode structure is arranged on the light-emitting surface of the chip.

[0120] Example 5

[0121] This embodiment discloses an electrode structure of an LED chip, comprising an ohmic contact layer, a reflective layer, an insulating layer, a conductive layer, a barrier layer and a bonding layer arranged in sequence along the light emitting direction of the LED chip.

[0122] The conductive layer is a Cu layer, the bonding layer is an Au layer, and the crystal structure of the barrier layer is different from the crystal structures of the conductive layer and the bonding layer.

[0123] The thickness of the bonding layer is less than 1 μm, and the thickness of the conductive layer and the thickness of the bonding layer are greater than or equal to 1 μm.

[0124] Wherein, the thickness of the conductive layer is The thickness of the bonding layer is

[0125] The electrode structure includes a P-type electrode and an N-type electrode, and both the P-type electrode and the N-type electrode include an electrode pad and an electrode strip, wherein the diameter of the electrode pad is 60 μm.

[0126] Wherein, the barrier layer is a Ti layer with a thickness of

[0127] The crystal structure of the insulating layer is different from the crystal structures of the reflective layer and the conductive layer.

[0128] Wherein, the insulating layer is a Ti layer with a thickness of

[0129] Wherein, the reflective layer is an Al layer, and the thickness of the reflective layer is

[0130] Wherein, the ohmic contact layer is a Cr layer, and the thickness of the ohmic contact layer is

[0131] This embodiment also discloses an LED chip, comprising the above-mentioned electrode structure.

[0132] The LED chip is a normal-mounted LED chip, and the electrode structure is arranged on the light-emitting surface of the chip.

[0133] Example 6

[0134] This embodiment discloses an electrode structure of an LED chip, comprising an ohmic contact layer, a reflective layer, an insulating layer, a conductive layer, a barrier layer and a bonding layer arranged in sequence along the light emitting direction of the LED chip.

[0135] The conductive layer is a Cu layer, the bonding layer is an Au layer, and the crystal structure of the barrier layer is different from the crystal structures of the conductive layer and the bonding layer.

[0136] The thickness of the bonding layer is less than 1 μm, and the thickness of the conductive layer and the thickness of the bonding layer are greater than or equal to 1 μm.

[0137] Wherein, the thickness of the conductive layer is The thickness of the bonding layer is

[0138] The electrode structure includes a P-type electrode and an N-type electrode, and both the P-type electrode and the N-type electrode include an electrode pad and an electrode strip, wherein the diameter of the electrode pad is 60 μm.

[0139] Wherein, the barrier layer is a Ti layer with a thickness of

[0140] The crystal structure of the insulating layer is different from the crystal structures of the reflective layer and the conductive layer.

[0141] Wherein, the insulating layer is a Ti layer with a thickness of

[0142] Wherein, the reflective layer is an Al layer, and the thickness of the reflective layer is

[0143] Wherein, the ohmic contact layer is a Cr layer, and the thickness of the ohmic contact layer is

[0144] This embodiment also discloses an LED chip, comprising the above-mentioned electrode structure.

[0145] The LED chip is a normal-mounted LED chip, and the electrode structure is arranged on the light-emitting surface of the chip.

[0146] Example 7

[0147] This embodiment discloses an electrode structure of an LED chip, comprising an ohmic contact layer, a reflective layer, an insulating layer, a conductive layer, a barrier layer and a bonding layer arranged in sequence along the light emitting direction of the LED chip.

[0148] The conductive layer is a Cu layer, the bonding layer is an Au layer, and the crystal structure of the barrier layer is different from the crystal structures of the conductive layer and the bonding layer.

[0149] The thickness of the bonding layer is less than 1 μm, and the thickness of the conductive layer and the thickness of the bonding layer are greater than or equal to 1 μm.

[0150] Wherein, the thickness of the conductive layer is The thickness of the bonding layer is

[0151] The electrode structure includes a P-type electrode and an N-type electrode, and both the P-type electrode and the N-type electrode include an electrode pad and an electrode strip, wherein the diameter of the electrode pad is 60 μm.

[0152] Wherein, the barrier layer is a Ti layer with a thickness of

[0153] The crystal structure of the insulating layer is different from the crystal structures of the reflective layer and the conductive layer.

[0154] Wherein, the insulating layer is a Ti layer with a thickness of

[0155] Wherein, the reflective layer is an Al layer, and the thickness of the reflective layer is

[0156] Wherein, the ohmic contact layer is a Cr layer, and the thickness of the ohmic contact layer is

[0157] This embodiment also discloses an LED chip, comprising the above-mentioned electrode structure.

[0158] The LED chip is a normal-mounted LED chip, and the electrode structure is arranged on the light-emitting surface of the chip.

[0159] Example 8

[0160] This embodiment discloses an electrode structure of an LED chip, comprising an ohmic contact layer, a reflective layer, an insulating layer, a conductive layer, a barrier layer and a bonding layer arranged in sequence along the light emitting direction of the LED chip.

[0161] The conductive layer is a Cu layer, the bonding layer is an Au layer, and the crystal structure of the barrier layer is different from the crystal structures of the conductive layer and the bonding layer.

[0162] The thickness of the bonding layer is less than 1 μm, and the thickness of the conductive layer and the thickness of the bonding layer are greater than or equal to 1 μm.

[0163] Wherein, the thickness of the conductive layer is The thickness of the bonding layer is

[0164] The electrode structure includes a P-type electrode and an N-type electrode, and both the P-type electrode and the N-type electrode include an electrode pad and an electrode strip, wherein the diameter of the electrode pad is 60 μm.

[0165] Wherein, the barrier layer is a Ti layer, and the thickness of the barrier layer is

[0166] Wherein, the coating layer is Ti / Ni / Pt / Ni / Pt / Ti layer, and the thickness of each layer is

[0167] Wherein, the reflective layer is an Al layer, and the thickness of the reflective layer is

[0168] Wherein, the ohmic contact layer is a Cr layer, and the thickness of the ohmic contact layer is

[0169] This embodiment also discloses an LED chip, comprising the above-mentioned electrode structure.

[0170] The LED chip is a normal-mounted LED chip, and the electrode structure is arranged on the light-emitting surface of the chip.

[0171] Example 9

[0172] This embodiment discloses an electrode structure of an LED chip, comprising an ohmic contact layer, a reflective layer, an insulating layer, a conductive layer, a barrier layer and a bonding layer arranged in sequence along the light emitting direction of the LED chip.

[0173] The conductive layer is a Cu layer, the bonding layer is an Au layer, and the crystal structure of the barrier layer is different from the crystal structures of the conductive layer and the bonding layer.

[0174] The thickness of the bonding layer is less than 1 μm, and the thickness of the conductive layer and the thickness of the bonding layer are greater than or equal to 1 μm.

[0175] Wherein, the thickness of the conductive layer is The thickness of the bonding layer is

[0176] The electrode structure includes a P-type electrode and an N-type electrode, and both the P-type electrode and the N-type electrode include an electrode pad and an electrode strip, wherein the diameter of the electrode pad is 60 μm.

[0177] Wherein, the barrier layer is a Ti layer, and the thickness of the barrier layer is

[0178] Wherein, the coating layer is Ti / Ni / Pt / Ni / Pt / Ti layer, and the thickness of each layer is

[0179] Wherein, the reflective layer is an Al layer, and the thickness of the reflective layer is

[0180] Wherein, the ohmic contact layer is a Cr layer, and the thickness of the ohmic contact layer is

[0181] This embodiment also discloses an LED chip, comprising the above-mentioned electrode structure.

[0182] The LED chip is a normal-mounted LED chip, and the electrode structure is arranged on the light-emitting surface of the chip.

[0183] Comparative Example 1

[0184] The difference between this comparative example and Example 2 is that the electrode structure of this comparative example does not have a barrier layer.

[0185] Comparative Example 2

[0186] This comparative example discloses an electrode structure of an LED chip, comprising an ohmic contact layer, a reflective layer, a cladding layer and a bonding layer sequentially arranged along the light emitting direction of the LED chip, wherein the conductive layer is a Cu layer and the bonding layer is an Au layer.

[0187] Wherein, the thickness of the bonding layer is

[0188] The electrode structure includes a P-type electrode and an N-type electrode, and both the P-type electrode and the N-type electrode include an electrode pad and an electrode strip, wherein the diameter of the electrode pad is 60 μm.

[0189] Wherein, the coating layer is Ti / Ni / Pt / Ni / Pt / Ti layer, and the thickness of each layer is

[0190] Wherein, the reflective layer is an Al layer, and the thickness of the reflective layer is

[0191] Wherein, the ohmic contact layer is a Cr layer, and the thickness of the ohmic contact layer is

[0192] This comparative example also discloses an LED chip, comprising the above-mentioned electrode structure.

[0193] The LED chip is a normal-mounted LED chip, and the electrode structure is arranged on the light-emitting surface of the chip.

[0194] Performance Test:

[0195] 1) Experimental group: Example 1 to Example 9, Comparative Example 1 to Comparative Example 2

[0196] 2) Test items:

[0197] According to each experimental group, a normal-mounted LED chip was prepared, and 300 LED chips were respectively selected to test their voltage and wire-bonding thrust values.

[0198] 3) Test results:

[0199] The average values ​​of the voltage and wire-bonding thrust values ​​of each experimental group, as well as the reduction in the wire-bonding layer thickness of Examples 1 to 9 relative to the wire-bonding layer thickness of Comparative Example 2 were calculated. The greater the reduction in the wire-bonding layer thickness, the less Au is used, and the lower the cost. The test results are as follows:

[0200]

[0201] Among them, by comparing Examples 1 to 3, Examples 5 to 7 with Comparative Example 2, it can be seen that compared with only setting a bonding layer, the present invention sets a conductive layer, an assembly layer and a bonding layer. When the total thickness of the conductive layer and the bonding layer of the present invention is equal to the bonding layer of Comparative Example 2, the voltage and the bonding thrust value are equivalent, but the present invention can greatly reduce the thickness of the bonding layer (Au), that is, the present invention can ensure that the chip has a voltage and bonding performance equivalent to that of Comparative Example 2 in which only a bonding layer is set while greatly reducing the amount of Au used.

[0202] By comparing Example 3 with Example 1 and Example 2 (or, comparing Example 6 with Example 5 and Example 7), it can be seen that when the bonding layer adopts the thinnest thickness, the thickness of Au can be reduced to the maximum while maintaining a voltage equivalent to that of other embodiments, but the bonding thrust value will decrease. However, in actual applications, this degree of bonding thrust value can achieve good long-term reliability and meet application requirements.

[0203] For Example 2, Example 8 and Example 9, it can be seen that increasing the thickness of the conductive layer can effectively reduce the voltage.

[0204] By comparing Example 2, Example 4 and Example 5, it can be seen that compared with setting a coating layer between the reflective layer and the conductive layer, setting an insulating layer between the reflective layer and the conductive layer can effectively reduce the amount of precious metal Pt, further reduce material costs, and at the same time ensure that the chip has a voltage and wire bonding performance equivalent to that of Example 2 in which a coating layer is set.

[0205] By comparing Example 2 with Comparative Example 1, it can be seen that when no interlayer is provided between the conductive layer and the bonding layer, the conductive layer and the bonding layer will dissolve into each other to form an alloy, making it difficult to form a bonding eutectic, resulting in a very low bonding thrust value, making it difficult to ensure long-term reliability.

[0206] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with the field can make some changes or modify the technical contents suggested above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the solution of the present invention.

Claims

1. An electrode structure of an LED chip, characterized in that: It includes an ohmic contact layer, a reflective layer, a coating layer or an insulating layer, a conductive layer, a barrier layer and a bonding layer which are sequentially arranged along the light emitting direction of the LED chip. The conductive layer is a Cu layer, the bonding layer is an Au layer, and the crystal structure of the barrier layer is different from the crystal structures of the conductive layer and the bonding layer.

2. The electrode structure of an LED chip according to claim 1, characterized in that: The thickness of the bonding layer is less than 1 μm, and the thickness of the conductive layer and the thickness of the bonding layer are greater than or equal to 1 μm.

3. The electrode structure of an LED chip according to claim 2, characterized in that: The electrode structure includes a P-type electrode and an N-type electrode, and both the P-type electrode and the N-type electrode include an electrode pad and an electrode strip. min =13.5 / D, where T min is the minimum thickness of the bonding layer, in μm; D is the diameter or width of the electrode pad, in μm, and D is 20 μm to 150 μm.

4. The electrode structure of an LED chip according to claim 1, characterized in that: The thickness of the conductive layer is 0.3 μm to 4 μm.

5. The electrode structure of an LED chip according to claim 1, characterized in that: The barrier layer is any one of a Cr layer and a Ti layer, or is formed by periodically alternating stacking of a Cr layer and a Ti layer. And / or, the thickness of the barrier layer is 50nm to 300nm.

6. The electrode structure of an LED chip according to claim 1, characterized in that: The crystal structure of the insulating layer is different from the crystal structures of the reflective layer and the conductive layer.

7. The electrode structure of an LED chip according to claim 6, characterized in that: The insulating layer is any one of a Cr layer and a Ti layer, or is formed by periodically alternating stacking of a Cr layer and a Ti layer. And / or, the thickness of the insulating layer is 80nm to 500nm.

8. The electrode structure of an LED chip according to claim 1, characterized in that: The coating layer is formed by periodically alternating any one or more non-precious metal layers of Cr layer, Ti layer, Ni layer and Pt layer. And / or, the coating layer has a thickness of 100 nm to 1000 nm.

9. The electrode structure of an LED chip according to claim 1, characterized in that: The reflective layer is an Al layer, and the thickness of the reflective layer is 50nm to 300nm; And / or, the ohmic contact layer is any one of a Cr layer, a Ti layer, and a Ni layer, and the thickness of the ohmic contact layer is 10. An LED chip, characterized in that: Comprising the electrode structure according to any one of claims 1 to 9.

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