CN105679925B - The preparation method and chip of chip are directly welded in display with red LED - Google Patents
The preparation method and chip of chip are directly welded in display with red LED Download PDFInfo
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- CN105679925B CN105679925B CN201410678056.2A CN201410678056A CN105679925B CN 105679925 B CN105679925 B CN 105679925B CN 201410678056 A CN201410678056 A CN 201410678056A CN 105679925 B CN105679925 B CN 105679925B
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Abstract
The present invention relates to a kind of displays directly to weld the preparation method and chip of chip with red LED, all carries out the first graphical treatment including the front and back to substrate；Successively carry out N-type epitaxy layer and p-type outer layer growth；The area N lithography and etching is carried out, exposes N-type epitaxy layer in the first patterned area；Deposit current barrier layer；Carry out current barrier layer photoetching and graphical etching；Deposit current-diffusion layer；Current-diffusion layer photoetching and graphical etching are carried out, p-type epitaxial layer is exposed in second graphical region, and expose N-type epitaxy layer in third patterned area；After preannealing, metal layer lithography and graphical etching are carried out；After ashing, metal evaporation is carried out；After removing, two electrodes are formed on second graphical region and third patterned area；Substrate laser lift-off is carried out, layer deposit is passivated to the N-type epitaxy layer surface exposed after removing；It obtains showing after annealing and directly welds chip with red LED.
Description
Technical field
The present invention relates to semiconductor fields, more particularly to the preparation method of chip is directly welded in-kind of display with red LED
And chip.
Background technique
Traditional semiconductor light emitting chip will first generate epitaxial wafer by MOCVD, and then rear process does electrode, then passes through
Downstream application is given in cutting classification, and " encapsulation " (PACKAGE) is first done before downstream application and then is fixed on the electricity of application product again
Road-load body (PCB) realizes relevant electric connection and function up.
After chip in the electrode fabrication of process, mainly produce to pass through when the use of downstream and can use ultrasonic bonding gold
The electrode of line or aluminum steel.
It first to be made before downstream application " encapsulation ", mainly of conductive elargol on reasonable bracket (FRAME)
Carry out die bond, safe one of electrode is installed and realizes electric connection, then again by ultrasonic wire welding machine the another of chip
One electrode gold thread or aluminum steel are welded and connected to another independent electrical pin of bracket, finally again with transparent epoxy resin brilliant
Piece, a part of bracket and the gold thread for connecting them or aluminum steel one reinstate the mould grain casting sealing for being beforehand with optical lens design
Get up.The pin of part electrical property bracket be it is exposed, be as be when being matched with other electronic devices SMT connect or
DIP plug-in unit installation is applied on the PCB of application product.
It is doing in " encapsulation " this procedure, it is inevitable that opaque gold or aluminium are left on light-emitting surface due to having to bonding wire
The light emission that line melting welding point has covered part goes out direction, and " black " heart of withered sky can be left in the hot spot of individual point light source
Point, rather than the uniform hot spot of ideal point light source.
In addition, under the requirement of market environment that semiconductor light emitting application increasingly tends to cost performance, to semiconductor light emitting crystalline substance
The service cost of piece proposes huge lower the requirement.
Summary of the invention
The object of the present invention is to provide a kind of low cost, the red LEDs of high light-emitting rate directly to weld the preparation method of chip
And chip, preparation method is simple, and it is light-emitting surface that top, which can be prepared, and bottom is positive and negative anodes, can be directly welded at PCB
Or for showing the LED wafer used on laminated circuit board.
The preparation method of chip, institute are directly welded with red LED in a first aspect, the embodiment of the invention provides a kind of displays
The method of stating includes:
First graphical treatment is all carried out to the front and back of substrate；The substrate includes Sapphire Substrate, GaAs lining
Bottom or SiC substrate；
N-type epitaxy layer and p-type outer layer growth are successively carried out on the first image conversion treated substrate, and is carried out
Chemically mechanical polishing；
The area N lithography and etching is carried out, exposes N-type epitaxy layer in the first patterned area；
Deposit current barrier layer；
Carry out current barrier layer photoetching and graphical etching；
Deposit current-diffusion layer；
Current-diffusion layer photoetching and graphical etching are carried out, exposes p-type epitaxial layer in second graphical region, and the
Expose N-type epitaxy layer in three patterned areas；
After preannealing, metal layer lithography and graphical etching are carried out；
After ashing, metal evaporation is carried out, deposits Cr, Ni, Au, Ti, Sn, wherein outermost layer is AuSn alloy；
Metal layer is removed；After removing, the crystalline substance is formed on the second graphical region and third patterned area
Two electrodes of piece；
Substrate laser lift-off is carried out to substrate using laser, layer is passivated to the N-type epitaxy layer surface exposed after removing
Deposit；
The display is obtained after annealing directly welds chip with red LED.
Preferably, the method also includes: after annealing, the red LED is directly welded chip carry out weldability mould
Quasi- test.
Preferably, after the use laser carries out substrate laser lift-off to substrate, the method also includes:
It mills to the surface of the N-type epitaxy layer left behind cutting peeling liner bottom；
And chip is directly welded to the red LED after cutting and carries out secondary passivity.
Preferably, the N-type epitaxy layer is specially N-type GaN or InGaN or InGaAIP.
Preferably, the p-type epitaxial layer is specially p-type GaN or InGaN or InGaAIP.
Second aspect, the embodiment of the invention provides a kind of red being prepared using above-mentioned first aspect the method
LED directly welds chip.
The preparation method of chip is directly welded with red LED in display provided by the invention, it is simple and easy to do, it can be prepared into
Chip is directly welded to the red LED for display.Chip uses eutectic electrode, so as to directly in application product
Eutectic welding procedure is done on PCB to complete the electric connection with other electronic components, save traditional encapsulation process process from
And effectively save equipment processing cost and cost of labor.
Detailed description of the invention
Fig. 1 is preparation method flow chart provided in an embodiment of the present invention；
Fig. 2 be red LED provided in an embodiment of the present invention directly weld chip prepare one of schematic diagram；
Fig. 3 is prepare schematic diagram two that red LED provided in an embodiment of the present invention directly welds chip；
Fig. 4 is prepare schematic diagram three that red LED provided in an embodiment of the present invention directly welds chip；
Fig. 5 is prepare schematic diagram four that red LED provided in an embodiment of the present invention directly welds chip；
Fig. 6 is prepare schematic diagram five that red LED provided in an embodiment of the present invention directly welds chip；
Fig. 7 is prepare schematic diagram six that red LED provided in an embodiment of the present invention directly welds chip；
Fig. 8 is prepare schematic diagram seven that red LED provided in an embodiment of the present invention directly welds chip；
Fig. 9 is prepare schematic diagram eight that red LED provided in an embodiment of the present invention directly welds chip；
Figure 10 is that red LED provided in an embodiment of the present invention directly welds chip.
Specific embodiment
The present invention is described in detail with reference to the accompanying drawings and examples.
The preparation method and LED crystalline substance of (Direct Attach, DA) chip are directly welded in display of the invention with red LED
Piece is mainly used for display aspect, mainly includes LED display, extra small space distance LED display screen, ultra high density LED display, LED
Just shine TV, the just luminous monitor of LED, LED video wall, LED indication, LED special lighting etc..
Fig. 1 is preparation method flow chart provided in an embodiment of the present invention, and Fig. 2-Fig. 8 is preparation provided in an embodiment of the present invention
Process schematic is below illustrated preparation method of the invention with Fig. 1 and in conjunction with Fig. 2-Fig. 8.
Step 101, the first graphical treatment is all carried out to the front and back of substrate；
Firstly, using graphical sapphire substrate (Pattern Sapphire Substrate, PSS) technique to substrate into
Row graphical treatment.Preferably, the graphical treatment is all patterned processing to the front and back of substrate.The substrate
Including Sapphire Substrate, GaAs substrate or SiC substrate.
After PSS is handled, the graphical front and back of substrate is for cut crystal laser knife after the completion of rear process
Tool can be aligned, and will not hurt wafer body.
Step 102, N-type epitaxy layer is successively carried out on the first image conversion treated substrate and p-type epitaxial layer is raw
It is long, and chemically-mechanicapolish polished；
Specifically, carrying out the growth of epitaxial layer in a side surface of substrate.Epitaxial growth can use metallorganic
The mode for learning vapor deposition (Metal-Organic Chemical Vapor Deposition, MOCVD) carries out.Wherein,
MOCVD is the former material using hydride of III group, the organic compound of II race element and V, VI race element etc. as crystal growth
Material, carry out vapour phase epitaxy on substrate in a manner of pyrolysis, grow various iii-vs, II-VI group compound semiconductor with
And the thin layer monocrystal material of their multivariate solid solution.For example, by MOCVD, it can be in the front deposit shape of patterned substrate
At PN junction, that is, form adjacent P-type layer and N-type layer.Depending on used raw material, epitaxial layer can be formed as gallium nitride
(GaN) or InGaN or InGaAIP, wherein P-type layer can be P-GaN or any one of InGaN or InGaAIP, and N-type layer is
N-GaN or any one of InGaN or InGaAIP.Sectional view after epitaxial growth is as shown in Figure 2.
Step 103, the area N lithography and etching is carried out, exposes N-type epitaxy layer in the first patterned area；
Specifically, firstly, using photoresist (Optical Resist, PR) and the mask plate with predetermined pattern to external
Prolong layer surface and carry out photoetching, so that the photoresist of epi-layer surface be made to form the predetermined pattern.The predetermined pattern is multiple repetitions
The array of pattern, each pattern hollow part in array is the position for needing to expose N-type epitaxy layer.
Next, being etched, the place of unglazed photoresist is etched into exposing N-type epitaxy layer, specifically such as Fig. 3 institute
Show.
Step 104, current barrier layer is deposited；
Specifically, the deposition of current barrier layer (Current Blocking Layer, CBL) is generally using deposit titanium dioxide
Silicon (SiO2) spacer medium layer as electric current.It does not shine, improves in this way, can allow and cannot go out light/light-blocking place (PN junction)
Electric current is efficiently injected into.
Step 105, current barrier layer photoetching and graphical etching are carried out；
Specifically, CBL lithography and etching is carried out after CBL deposition, the SiO in the place that no photoresist is protected2Etching
Fall, exposed portion n-type region.
Step 106, current-diffusion layer is deposited；
Specifically, the deposition of current-diffusion layer generally deposit nano indium tin oxide (lndium Tin Oxides,
ITO).It is as shown in Figure 4 after deposit.
Step 107, current-diffusion layer photoetching and graphical etching are carried out, p-type extension is exposed in second graphical region
Layer, and expose N-type epitaxy layer in third patterned area；
Specifically, the region for needing to retain ITO is protected with photoresist, the ITO in the place that no photoresist is protected
And SiO2It etches away, exposes p-type epitaxial layer and N-type epitaxy layer respectively, as shown in Figure 5.
Step 108, after preannealing, metal layer lithography and graphical etching are carried out；
Specifically, carrying out a high-temperature heat treatment to chip by preannealing, forward voltage can reduce, in current spread
Layer surface contacts to be formed.
After metal layer lithography and graphical etching, the figure of the reserved eutectic electrode of deposited metal is formed.As shown in Figure 6.
Step 109, after ashing, metal evaporation is carried out, deposits Cr, Ni, Au, Ti, Sn, wherein outermost layer is AuSn alloy；
Specifically, ashing (Asher) technique uses the removing of photoresist by plasma, wafer surface is cleaned using oxygen, nitrogen, so that brilliant
Piece surface more smooth, and the negtive photoresist at electrode can be removed and improve electrode adhesiveness.
Step 110, metal layer is removed；After removing, the shape on the second graphical region and third patterned area
At two electrodes of the chip；
Specifically, being removed to metal layer, the metal-stripping other than electrode is fallen, in the second graphical region and
Two electrodes (PAD in figure) of the chip are formed in third patterned area, as shown in Figure 7.
Step 111, using laser to substrate carry out substrate laser lift-off, to the N-type epitaxy layer surface exposed after removing into
The deposit of row passivation layer；
Specifically, directly welding chip to the red LED using laser carries out substrate laser lift-off (Laser Lift
Off, LLO), as shown in figure 8, the substrate is cut to remaining 0-3 μm.The purpose for the arrangement is that for red LED chip energy
It is enough that light is gone out by top surface well, without being blocked by substrate.Then, the substrate surface after cutting is chemically-mechanicapolish polished,
And directly weld chip to the red LED after cutting and carry out secondary passivity, passivation protection layer is formed in the side wall of LED wafer.It is blunt
Changing layer deposit can be as shown in figure 9, deposits passivation protection layer in surrounding them.
Step 112, the display is obtained after annealing directly weld chip with red LED.
After anneal, chip can be directly welded to red LED carries out weldability simulation test (Weldability
Simulation Test, WST), to test the adhesiveness of electrode in welding.
Finally, classify by automated visual inspection, it can shipment after packaging.The LED being finally prepared directly welds crystalline substance
Piece can be as shown in Figure 10.
The preparation method of chip is directly welded with red LED in display provided by the invention, it is simple and easy to do, it can be prepared into
Chip is directly welded to the red LED for display.Chip uses eutectic electrode, so as to directly in application product
Eutectic welding procedure is done on PCB to complete the electric connection with other electronic components, save traditional encapsulation process process from
And effectively save equipment processing cost and cost of labor.
Based on direct welding (DA) chip that above-mentioned preparation method obtains, using the aluminium indium gallium phosphorus phosphorus quaternary of high-luminous-efficiency
Materials and GaAs substrates, silicon carbide (SiC) substrate or Sapphire Substrate (Al2O3) such as plain (AllnGaP) are not limited only to this
Other substrates are made, and are the reverse mould inverted structure for going out light at the top of high brightness, have low driving voltage, the characteristics such as high photosynthetic efficiency.Directly
The pad for mounting or being welded with carrier board circuit, or directly ITO technique makes driving circuit, completes FPD production.
Its typical structure size can be as follows:
Table 1
In conjunction with such as the following table 2 to table 4, the main object properties of LED wafer of the invention can be learnt.
| Main Physical Characteristics | Parameter |
| Wavelength (nm) | 500-770 |
| Power (mw) | ≤80 |
Table 2
| Ta=25 DEG C of electrical characteristic | Parameter |
| Wavelength (nm) | 450-470 |
| Power (mw) | ≤80 |
| Forward voltage (V) | 1.85~3.6 |
| Forward current (mA) | Without limitation |
| Peak forward current (mA) | 10-30 |
| Backward voltage (V) | 5 |
| Reverse current (μ A) | Less than 2 |
| Half band-width (nm) | 20 |
| Operating temperature (DEG C) | -40-+100 |
| Storage temperature (DEG C) | -40-+100 |
| Electrostatic load threshold value (HBM) (V) | 1000 |
| Electrostatic load class (MIL-STD-883E) | 2 |
Table 3
Red LED provided in an embodiment of the present invention directly welds chip, has low driving voltage, the characteristics such as high photosynthetic efficiency, energy
Enough provide uniformly goes out light.Eutectic welding procedure can directly be done to complete on the PCB of application product using eutectic electrode simultaneously
With the electric connection of other electronic components, traditional encapsulation process process is saved to effectively save equipment processing cost
And cost of labor.
In addition, LED eutectic chip provided by the invention breaches semiconductor light emitting chip in 1.0 milli of small spacing (PITCH)
Rice application limitation below, because semiconductor emitters will not be limited to again because of post-processing (conventional package) bring additional volumes
Limitation, the eutectic device of arbitrary dimension can be made.It is possible thereby to realize the application of broader semiconductor light emitting.
It should be noted that, although the present invention is illustrated so that red LED directly welds the preparation process of chip as an example,
But the present invention is not limited to prepare red LED eutectic chip, the LED eutectic chip that this method prepares other colors can also be used.
Above-described specific embodiment has carried out further the purpose of the present invention, technical scheme and beneficial effects
It is described in detail, it should be understood that being not intended to limit the present invention the foregoing is merely a specific embodiment of the invention
Protection scope, all within the spirits and principles of the present invention, any modification, equivalent substitution, improvement and etc. done should all include
Within protection scope of the present invention.
Claims (7)
1. the preparation method that chip is directly welded in a kind of display with red LED, which is characterized in that the described method includes:
First graphical treatment is all carried out to the front and back of substrate；The substrate include Sapphire Substrate, GaAs substrate or
SiC substrate；
N-type epitaxy layer and p-type outer layer growth are successively carried out on the first image conversion treated substrate, and carries out chemistry
Mechanical polishing；
The area N lithography and etching is carried out, rock outside N-type is exposed in the first patterned area and prolongs layer；
Deposit current barrier layer；
Carry out current barrier layer photoetching and graphical etching；
Deposit current-diffusion layer；
Current-diffusion layer photoetching and graphical etching are carried out, p-type epitaxial layer is exposed in second graphical region, and in third figure
Expose substrate in shape region；
After preannealing, metal layer lithography and graphical etching are carried out；
After ashing, metal evaporation is carried out, deposits Cr, Ni, Au, Ti, Sn, wherein outermost layer is AuSn alloy；
Metal layer is removed；After removing, the chip is formed on the second graphical region and third patterned area
Two electrodes；
Laser lift-off is carried out to the substrate, to obtain the chip；
To the annealing of wafer, the display is obtained with red LED and directly welds chip.
2. the method according to claim 1, wherein the method also includes: after annealing, to the red
LED directly welds chip and carries out weldability simulation test.
3. the method according to claim 1, wherein described carry out laser lift-off to the substrate specifically:
Substrate cutting is carried out to substrate using laser, remaining substrate thickness is no more than 3 microns after cutting.
4. according to the method described in claim 3, it is characterized in that, the substrate carry out laser lift-off after, the method
Further include:
It grinds on the surface of the N-type epitaxy layer left after being sunk to the bottom to cutting removing
And secondary passivity is carried out to the chip.
5. LED eutectic chip according to claim 1, which is characterized in that the N-type epitaxy layer be specially N-type GaN or
InGaN or AlGaN or AlGaInP.
6. LED eutectic chip according to claim 1, which is characterized in that the p-type epitaxial layer be specially p-type GaN or
InGaN or AlGaN or AlGaInP.
7. a kind of red LED being prepared using any the method for the claims 1-6 directly welds chip.
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| CN106299097B (en) * | 2016-10-11 | 2024-02-09 | 黄福强 | Positive luminous LED, lamp strip and high-transmittance display screen are just pasted |
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| CN101009344A (en) * | 2006-01-27 | 2007-08-01 | 杭州士兰明芯科技有限公司 | Coarse sapphire bushing LED and its making method |
| CN101933166A (en) * | 2007-11-14 | 2010-12-29 | 克利公司 | No wire-bonded wafer level led |
| CN102403425A (en) * | 2011-11-25 | 2012-04-04 | 俞国宏 | Method for manufacturing inverted LED chip |
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| CN103311385A (en) * | 2013-05-21 | 2013-09-18 | 严敏 | Manufacturing method for semiconductor lighting DA (direct attach) eutectic chip |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103579447B (en) * | 2012-08-03 | 2016-12-21 | 同方光电科技有限公司 | A kind of inverted structure light emitting diode and preparation method thereof |
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101009344A (en) * | 2006-01-27 | 2007-08-01 | 杭州士兰明芯科技有限公司 | Coarse sapphire bushing LED and its making method |
| CN101933166A (en) * | 2007-11-14 | 2010-12-29 | 克利公司 | No wire-bonded wafer level led |
| CN102403425A (en) * | 2011-11-25 | 2012-04-04 | 俞国宏 | Method for manufacturing inverted LED chip |
| CN102769083A (en) * | 2012-07-16 | 2012-11-07 | 江苏扬景光电有限公司 | Flip-chip bonding nitride light emitting diode (LED), light-transmission substrate thereof, and methods for manufacturing light-transmission substrate |
| CN103311385A (en) * | 2013-05-21 | 2013-09-18 | 严敏 | Manufacturing method for semiconductor lighting DA (direct attach) eutectic chip |
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