Aluminium Nitride na motsa zafi kamar ƙarfe kuma har yanzu yana hana wutar lantarki

Alumina ita ce tushen seramiki na tsoho saboda wani dalili. Yana da arha, mai ƙarfi, kuma mai sauƙin haɗa shi da ƙarfe. Haka kuma, bututun zafi ne mara kyau. Allon 96% Al₂O₃ yana da kusan 20–30 W/m·K. Nitride na aluminium, idan an yi shi yadda ya kamata, yana cikin kewayon 170–200 W/m·K, wani lokaci ya zarce 200. Ka'idar kristal ɗaya cikakke tana kusan 320. Babu wanda ke samar da shi. Abin da muke samarwa shi ne insulator da aka sinter wanda zai iya fitar da zafin die daga modul ɗin wuta ba tare da ya zama mai gudanar da lantarki ba.

Wannan haɗin shine aikin. Karfe suna watsawa zafi da wutar lantarki. Yawancin keramiki suna toshe wutar lantarki kuma suna kama zafi. Aluminum nitride yana watsawa zafi kuma yana ba da kariya a lokaci guda, tare da CTE kusan 4.5 ppm/°C — kusa da silicon. Alumina tana faɗaɗa kusan 6.5–7.5. A kan na'urar IGBT mai ƙarfi ko ta SiC, rashin daidaito yana bayyana a matsayin gajiya a walda da kuma zamewar foil na tagulla. BeO yana watsawa zafi mafi kyau, amma muna gujewa amfani da shi duk lokacin da zai yiwu. Guba ba ƙananan bayanin ƙasa a takardar bayanai ba ne.

Iska (oxygen) ita ce ƙazanta da ke lalata labarin gudanar da wutar lantarki. Iska a cikin tsarin lattice tana haifar da guraben aluminium. Fonons suna bazuwa. Foda mai kusan kashi biyu cikin ɗari na iska yana sintering zuwa wani abu da yake kama da AlN kuma yana da ƙima kusan 100 W/m·K. Foda mai ƙarancin iskar oxygen tare da abin taimako na sintering da ke jan oxygen zuwa matakin iyakar ƙwayoyin — yttria shi ne akafi amfani da shi — shine yadda ake samun darajar fiye da 170. Dangin dole ne ya kasance mai yawa. Ramuka na saura wani wurin bazuwar ne. Don haka “AlN substrate” a PO ba daraja bane. Ka tambayi gudanar zafi, ba kimiyyar sinadarai kawai ba.

Sarrafa foda shi ne inda shaguna ke mamaki. AlN mai laushi yana rushewa ta ruwa. Idan ka bar shi a cikin iska mai danshi, zai samu fata ta hydroxide kuma zai ƙara iskar oxygen da ka biya don a cire. Ajiya a busasshen wuri, lokacin buɗewa gajere, wani lokaci maganin saman. Wannan ba wai wahala ba ce. Haka kima (k-value) ke tsira har zuwa cikin tanda.

Muna amfani da aluminum nitride inda tarin zafi ke buƙatar sa: allunan wutar DBC da DPC, kunshin RF, submounts na laser da LED, wasu sassan tsarin semiconductor. Idan die ɗin na da ƙarfin watt kaɗan kuma heat sink ne ke zama matsanancin takura, alumina har yanzu tafi arha. Idan kuna zubar da watt da dama ta cikin siramiki mai siriri zuwa tagulla, raguwar zafi a saman alumina ba ta kasance kyauta ba. Siramiki yana da tsada fiye. Module ɗin da ba ya rage aiki ko rabuwa shi ne mai dawowa.

Sarrafawa da yin metallization suna buƙatar gaskiya iri ɗaya. AlN ba abu ne na yau da kullum kamar alumina 96% ba. Gicciye suna yagewa. Dangantakar jan ƙarfe dole ta yi daidai da faɗaɗa. Diski mai kyau na 180 W/m·K da mummunan haɗi kawai mai hana wutar lantarki ne mai tsada. Bayyana k, kauri, fuska, da tsarin ƙarfe a lokaci guda. Aluminium nitride hanya ce ta zafi wadda a zahiri take zama seramiki. Idan aka ɗauke shi haka, zai sami ƙima ta musamman. Idan aka ɗauke shi kamar alumina fari mai takardar talla mafi kyau, ba zai sami hakan ba.