Yini iI-chip ye-LED? Ngakho yiziphi izici zayo?Ukukhiqizwa kwe-chip ye-LEDikakhulukazi ukukhiqiza i-electrode yokuxhumana ye-ohm esebenza kahle futhi enokwethenjelwa, ukuhlangabezana nokwehla kwamandla kagesi amancane phakathi kwezinto ezithintekayo, ukunikeza iphedi yokucindezela yocingo lokushisela, futhi ngesikhathi esifanayo, ukukhanya okuningi ngangokunokwenzeka. Inqubo yefilimu yenguquko ngokuvamile isebenzisa indlela yokuhwamuka kwe-vacuum. Ngaphansi kwe-vacuum engu-4Pa ephezulu, izinto ezisetshenziswayo zincibilika ngokushisisa kokumelana noma ukufudumeza kwe-electron beam bombardment, futhi i-BZX79C18 iguqulwa ibe umhwamuko wensimbi ukuze ifakwe ebusweni bezinto zokwenziwa kwe-semiconductor ngaphansi kwengcindezi ephansi.

Izinsimbi ezisetshenziswa kakhulu zohlobo lwe-P zihlanganisa i-AuBe, i-AuZn namanye ama-alloys, futhi izinsimbi zokuthinta ohlangothini lwe-N ngokuvamile ziyi-alloys ye-AuGeNi. Isendlalelo se-alloy esakhiwe ngemva kokumbozwa sidinga futhi ukudalula indawo ekhanyayo ngangokunokwenzeka nge-photolithography, ukuze ungqimba olusele lwe-alloy lukwazi ukuhlangabezana nezidingo ze-electrode yokuxhumana ephansi ye-ohm esebenzayo kanye ne-welding line pad. Ngemuva kokuthi inqubo ye-photolithography isiqediwe, inqubo yokuhlanganisa izokwenziwa ngaphansi kokuvikelwa kwe-H2 noma i-N2. Isikhathi nokushisa kwe-alloying kuvame ukunqunywa ngokuya ngezimpawu zezinto zokwakha ze-semiconductor kanye nesimo sesithando somlilo we-alloy. Yiqiniso, uma inqubo ye-chip electrode efana ne-blue-green iyinkimbinkimbi kakhulu, ukukhula kwefilimu ye-passive kanye nenqubo yokufaka i-plasma kudingeka kwengezwe.

Enqubweni yokukhiqiza i-chip ye-LED, yiziphi izinqubo ezinomthelela obalulekile ekusebenzeni kwayo kwe-photoelectric?

Ngokuvamile, ngemva kokuphothulwa kokukhiqizwa kwe-LED epitaxial, ukusebenza kwayo okuyinhloko kagesi sekuqediwe. Ukwenziwa kwama-chip ngeke kuguqule imvelo yakho yokukhiqiza ewumongo, kodwa izimo ezingafanele enqubweni yokuhlanganisa nokuhlanganisa ingxubevange zizodala ukuthi ezinye imingcele zikagesi zibe zimbi. Isibonelo, izinga lokushisa eliphansi noma eliphezulu le-alloying lizodala ukuthintana kahle kwe-ohmic, okuyisizathu esiyinhloko sokwehla kwamandla kagesi aphambili aphezulu e-VF ekukhiqizeni ama-chip. Ngemuva kokusika, uma inqubo yokuqopha yenziwa onqenqemeni lwe-chip, kuzosiza ukuthuthukisa ukuvuza okubuyela emuva kwe-chip. Lokhu kungenxa yokuthi ngemva kokusika ngensimbi yesondo lokugaya idayimane, kuzoba nenqwaba yemfucumfucu eyimpushana esele onqenqemeni lwe-chip. Uma lezi zinhlayiya zinamathela ekuhlanganeni kwe-PN kwe-chip ye-LED, zizobangela ukuvuza kukagesi, noma ngisho nokuphuka. Ukwengeza, uma i-photoresist endaweni ye-chip ingahlutshiwe ngokuhlanzekile, izodala ubunzima ekuboshweni kwezintambo zangaphambili kanye nokunamathisela okungamanga. Uma ingemuva, izophinde ibangele ukwehla komfutho ophezulu. Enqubweni yokukhiqiza ama-chip, amandla okukhanya angathuthukiswa ngokusebenzisa ukuqina komhlaba kanye nokusikwa kusakhiwo se-trapezoid esihlanekezelwe.

Kungani ama-chips e-LED ahlukaniswa ngamasayizi ahlukene? Iyini imiphumela yosayizi kuI-LED photoelectricukusebenza?

Usayizi we-chip we-LED ungahlukaniswa ube yi-chip encane yamandla, i-chip yamandla aphakathi nendawo kanye ne-chip yamandla aphezulu ngokusho kwamandla. Ngokwezidingo zamakhasimende, ingahlukaniswa ngezinga elilodwa leshubhu, izinga ledijithali, izinga le-lattice nokukhanyisa okuhlobisa nezinye izigaba. Usayizi othize we-chip uncike ezingeni langempela lokukhiqiza labakhiqizi abahlukene be-chip, futhi asikho isidingo esiqondile. Uma nje inqubo ifanelekile, i-chip ingathuthukisa okukhiphayo kweyunithi futhi inciphise izindleko, futhi ukusebenza kwe-photoelectric ngeke kushintshe ngokuyisisekelo. Eyamanje esetshenziswa chip empeleni ihlobene nokuminyana kwamanje okugeleza ku-chip. I-current esetshenziswa i-chip incane futhi yamanje esetshenziswa yi-chip inkulu. Ukuminyana kweyunithi yabo kwamanje kuyafana. Uma kucatshangelwa ukuthi ukuchithwa kokushisa kuyinkinga eyinhloko ngaphansi kwamandla aphezulu, ukusebenza kahle kwawo okukhanyayo kuphansi kunalokho okungaphansi kwamandla aphansi. Ngakolunye uhlangothi, njengoba indawo ikhula, ukumelana nevolumu ye-chip kuzokwehla, ngakho-ke i-voltage conduction yangaphambili izokwehla.

Imuphi usayizi we-chip i-LED yamandla aphezulu evame ukubhekisa kuyo? Kungani?

Ama-chips anamandla aphezulu e-LED asetshenziselwa ukukhanya okumhlophe ngokuvamile angabonakala emakethe cishe ngamamitha angu-40, futhi okuthiwa ama-chips anamandla aphezulu ngokuvamile asho ukuthi amandla kagesi angaphezu kuka-1W. Njengoba ukusebenza kahle kwe-quantum ngokuvamile kungaphansi kuka-20%, iningi lamandla kagesi lizoguqulwa libe amandla okushisa, ngakho-ke ukuchithwa kokushisa kwama-chips aphezulu kubaluleke kakhulu, kudinga indawo enkulu ye-chip.

Yiziphi izidingo ezihlukene zenqubo ye-chip kanye nemishini yokucubungula yokukhiqiza izinto ze-GaN epitaxial uma kuqhathaniswa ne-GaP, i-GaAs ne-InGaAlP? Kungani?

Ama-substrates ama-chips ajwayelekile abomvu naphuzi e-LED nama-chips abomvu naphuzi e-quaternary enziwe nge-GaP, ama-GaAs nezinye izinto ezihlanganisiwe ze-semiconductor, ngokuvamile ezingenziwa zibe ama-substrates ohlobo lwe-N. Inqubo emanzi isetshenziselwa i-photolithography, futhi kamuva i-blade yesondo ledayimane isetshenziselwa ukusika ama-chips. I-chip eluhlaza okwesibhakabhaka yezinto ze-GaN i-substrate yesafire. Ngenxa yokuthi i-sapphire substrate i-insulated, ayikwazi ukusetshenziswa njengesigxobo se-LED. Ama-electrode e-P/N kufanele enziwe endaweni ye-epitaxial kanyekanye ngenqubo yokuqopha eyomile futhi nangezinqubo ezithile zokudlula. Ngenxa yokuthi amasafire aqinile kakhulu, kunzima ukusika ama-chips ngezinsimbi zamasondo okugaya idayimane. Inqubo yayo ngokuvamile iyinkimbinkimbi kakhulu kunaleyo ye-GaP nama-GaAs LEDs.

Iyini isakhiwo nezici ze-chip "electrode esobala"?

I-electrode ebizwa ngokuthi i-transparent kufanele ikwazi ukuqhuba ugesi nokukhanya. Le nto manje isetshenziswa kabanzi kunqubo yokukhiqiza i-crystal liquid. Igama layo yi-Indium Tin Oxide (ITO), kodwa ayikwazi ukusetshenziswa njengephedi yokushisela. Ngesikhathi sokwenziwa, i-electrode ye-ohmic izokwenziwa endaweni ye-chip, bese ungqimba lwe-ITO lugcotshwe phezulu, bese kuthi ungqimba lwe-welding pad luboshwe endaweni ye-ITO. Ngale ndlela, i-current from lead isatshalaliswa ngokulinganayo ku-electrode yokuxhumana ye-ohmic ngayinye ngesendlalelo se-ITO. Ngesikhathi esifanayo, njengoba inkomba ye-ITO ye-refractive iphakathi komoya kanye nenkomba ye-refractive yezinto ze-epitaxial, i-angle yokukhanya ingandiswa, futhi i-flux ekhanyayo nayo ingandiswa.

Iyini inkambiso yobuchwepheshe be-chip bokukhanyisa kwe-semiconductor?

Ngokuthuthukiswa kobuchwepheshe be-semiconductor LED, ukusetshenziswa kwayo emkhakheni wokukhanyisa kuyanda, ikakhulukazi ukuvela kwe-LED emhlophe, okuye kwaba ukugxila kokukhanyisa kwe-semiconductor. Kodwa-ke, i-chip eyisihluthulelo nobuchwepheshe bokupakisha zisadinga ukuthuthukiswa, futhi i-chip kufanele ithuthukiswe ibe namandla aphezulu, ukusebenza kahle okuphezulu kokukhanya kanye nokumelana nokushisa okuphansi. Ukwandisa amandla kusho ukukhulisa amandla asetshenziswa yi-chip. Indlela eqondile kakhulu ukukhulisa usayizi we-chip. Namuhla, ama-chips anamandla amakhulu wonke angu-1mm × 1mm, kanti okwamanje yi-350mA Ngenxa yokwanda kokusetshenziswa kwamanje, inkinga yokukhishwa kokushisa isiyinkinga evelele. Manje le nkinga isixazululwe ngokuyisisekelo nge-chip flip. Ngokuthuthukiswa kobuchwepheshe be-LED, ukusetshenziswa kwayo emkhakheni wokukhanyisa kuzobhekana nethuba elingakaze libonwe kanye nenselelo.

Yini i-Flip Chip? Sinjani isakhiwo sawo? Yiziphi izinzuzo zayo?

I-Blue LED ivamise ukusebenzisa i-Al2O3 substrate. I-Al2O3 substrate inobulukhuni obuphezulu, ukuqhutshwa kwe-thermal okuphansi kanye ne-conductivity. Uma isakhiwo esihle sisetshenziswa, ngakolunye uhlangothi, kuzodala izinkinga eziphikisana ne-static, ngakolunye uhlangothi, ukuchithwa kokushisa kuzoba yinkinga enkulu ngaphansi kwezimo eziphezulu zamanje. Ngesikhathi esifanayo, ngenxa yokuthi i-electrode yangaphambili ibheke phezulu, ingxenye yokukhanya izovinjelwa, futhi ukusebenza kahle okukhanyayo kuzoncishiswa. I-LED enamandla aluhlaza okwesibhakabhaka ingathola ukukhanya okuphumayo okusebenzayo kunobuchwepheshe bokupakisha bendabuko ngobuchwepheshe be-chip flip chip.

Indlela yamanje yesakhiwo se-flip esivamile yilena: okokuqala, lungiselela usayizi omkhulu we-LED chip enomshini wokushisela we-eutectic ofanelekile, ngesikhathi esifanayo, lungisa i-silicon substrate enkulu kancane kune-chip ye-LED eluhlaza okwesibhakabhaka, futhi ukhiqize ungqimba lwegolide oluqhutshwayo kanye nocingo oluholayo. ungqimba (i-ultrasonic wire ball solder joint) ye-eutectic welding. Bese, i-chip ye-LED enamandla amakhulu aluhlaza kanye ne-silicon substrate zishiselwa ndawonye kusetshenziswa imishini yokushisela ye-eutectic.

Lesi sakhiwo sibonakala ngokuthi ungqimba lwe-epitaxial luthintana ngokuqondile ne-silicon substrate, futhi ukumelana nokushisa kwe-silicon substrate kuphansi kakhulu kune-sapphire substrate, ngakho-ke inkinga yokushisa ukushisa ixazululwa kahle. Njengoba i-substrate yesafire ibheke phezulu ngemva kokuguqulwa, iba indawo ekhipha ukukhanya. Isafire isobala, ngakho inkinga yokukhipha ukukhanya nayo iyaxazululwa. Okungenhla ulwazi olufanele lobuchwepheshe be-LED. Ngikholelwa ukuthi ngokuthuthukiswa kwesayensi nobuchwepheshe, izibani ze-LED esikhathini esizayo zizoba ngcono nakakhulu, futhi impilo yabo yesevisi izothuthukiswa kakhulu, ilethe ukukhululeka okukhulu.