search query: @keyword electroluminescence / total: 7
reference: 3 / 7
« previous | next »
Author:Sippola, Perttu
Title:Packaging process development for visible LEDs
Pakkausprosessikehitys näkyvän alueen LED:eille
Publication type:Master's thesis
Publication year:2014
Pages:vi + 61 s. + liitt. 12      Language:   eng
Department/School:Sähkötekniikan korkeakoulu
Main subject:Mikro- ja nanotekniikka   (S3010)
Supervisor:Sopanen, Markku
Instructor:Riuttanen, Lauri
Electronic version URL: http://urn.fi/URN:NBN:fi:aalto-201404231727
OEVS:
Electronic archive copy is available via Aalto Thesis Database.
Instructions

Reading digital theses in the closed network of the Aalto University Harald Herlin Learning Centre

In the closed network of Learning Centre you can read digital and digitized theses not available in the open network.

The Learning Centre contact details and opening hours: https://learningcentre.aalto.fi/en/harald-herlin-learning-centre/

You can read theses on the Learning Centre customer computers, which are available on all floors.

Logging on to the customer computers

  • Aalto University staff members log on to the customer computer using the Aalto username and password.
  • Other customers log on using a shared username and password.

Opening a thesis

  • On the desktop of the customer computers, you will find an icon titled:

    Aalto Thesis Database

  • Click on the icon to search for and open the thesis you are looking for from Aaltodoc database. You can find the thesis file by clicking the link on the OEV or OEVS field.

Reading the thesis

  • You can either print the thesis or read it on the customer computer screen.
  • You cannot save the thesis file on a flash drive or email it.
  • You cannot copy text or images from the file.
  • You cannot edit the file.

Printing the thesis

  • You can print the thesis for your personal study or research use.
  • Aalto University students and staff members may print black-and-white prints on the PrintingPoint devices when using the computer with personal Aalto username and password. Color printing is possible using the printer u90203-psc3, which is located near the customer service. Color printing is subject to a charge to Aalto University students and staff members.
  • Other customers can use the printer u90203-psc3. All printing is subject to a charge to non-University members.
Location:P1 Ark Aalto  1017   | Archive
Keywords:LED
packaging
back-end-process
dicing
chip attachment
wire-bonding
epoxy encapsulation
electroluminescence
pakkaus
back-end -prosessi
kiekkosahaus
sirukiinnitys
lanka-bondaus
epoksi
elektroluminesenssi
Abstract (eng):The back-end processing of light-emitting diode (LED) lighting incurs the highest cost quantity for the whole production.
This hinders the adoption of highly efficient LEDs.
In this work a packaging process for visible LEDs was developed.
The research and development was carried out at the Optoelectronics research group of Aalto University.
The performance of the packaged LEDs was studied by electroluminescence (EL) measurements and the encapsulation epoxy with optical transmission measurements.
The packaging process consisted of four main stages.
First, the singulation of the processed sapphire wafer into chips was performed with a blade-based dicing machine.
Second, the LED chip was bonded with attachment epoxy onto a TO-46 two-pin metallic header.
Third, wire-bonding was performed by an aluminum bond wire from the chip contacts to the header contacts.
Finally, encapsulation was carried out with a transparent packaging epoxy.
As a result, in-house fabricated blue LED devices operating on 20 mA drive current were produced for research purposes.
It was observed with absolute irradiance measurements that the back-end processed LEDs can provide external quantum efficiencies (EQE) of 5,3 % and of 3,5 mW optical output powers with a 20 mA current.
Furthermore, the studies of the used epoxy showed a high transmission for the average operation wavelength of the used LEDs.
Also, the uniformity of the performance metrics of a processed LED wafer was tested by packaging and characterizing LEDs at three different wafer locations before and after encapsulation.
Results showed that there were slight on-wafer performance variations regarding the optical power and the EQE.
Moreover, optical power degradation was observed after encapsulation.
Abstract (fin):Valoa emittoivien diodien (LED) pakkausprosessi on suurin kuluerä koko tuotannossa.
Tämä hidastaa korkean hyötysuhteen LED:ien laajaa omaksumista yleisvalaistukseen.
Tässä diplomityössä kehitettiin pakkausprosessi optisen alueen LED:lle.
Tutkimus ja kehitys suoritettiin Aalto-yliopiston Optoelektroniikan tutkimusryhmässä.
Pakattujen LED:ien suorituskykyä tutkittiin elektroluminesenssi-mittauksilla ja pakkausepoksia optisella transmissiomittauksella.
Kehitetty pakkausprosessi koostuu neljästä päävaiheesta.
Ensin prosessoitu safiirikiekko sahataan yksittäisiksi LED-siruiksi kiekkosahalla.
Seuraavaksi LEDsiru kiinnitetään metalliseen kahden pinnin TO-46 alustaan kiinnitysepoksilla.
Tämän jälkeen sirun sähköiset kontaktit liitetään alumiinilangalla metallialustan kontakteihin.
Lopulta LED-komponentti koteloidaan valamalla se läpinäkyvään pakkausepoksiin.
Työn tuloksena valmistettiin sinisiä matalateho-LED:ejä tutkimustarkoituksiin.
Mittausten tuloksena todettiin valitun kupuepoksin pystyvän korkeaan transmissioon sinisten LED:ien emissioaallonpituudella ja koko näkyvällä alueella.
Elektroluminesenssimittausten tuloksena puolestaan havaittiin pakkausprosessoitujen LED:ien pystyvän tuottamaan 5,3 % ulkoisen kvanttihyötysuhteen (EQE, external quantum efficiency) ja 3,5 mW optisen tehon 20 mA ajovirralla.
Optista suorituskykyä mittattiin ja vertailtiin myös prosessoidun kiekon kolmen eri alueen LEDsiruista ennen ja jälkeen epoksikoteloinnin.
Mittaukset osoittivat LED-kiekolla esiintyvän eroja LED:ien optisessa tehossa ja EQE:ssä.
Lisäksi epoksin todettiin laskevan emittoituvaa optista tehoa.
Silti pakkausprosessin laadun todettiin täyttävän LED-pakkauksen vaatimukset riittävästi.
ED:2014-05-04
INSSI record number: 48959
+ add basket
« previous | next »
INSSI