Insights From Leading Edge

IFTLE 308 SEMICON Taiwan Part 2: Laser Processing for WLP; IoT in the Post-Smart Phone Era

By Dr. Phil Garrou, Contributing Editor

Continuing our look at Advanced Packaging in SEMICON Taiwan 2016.

AMKOR – Lasers for the Manufacture of WLCSP

WL Huang of Amkor examined the use of lasers in the manufacture of WLCSP (fan-in WLP). As we all know by now Huang pointed to size, weight, cost and performance as the drivers for WLCSP.

In the following chart, Huang shows that the same 7.6 x 7.6mm chip with 28 I/O saves a lot of real estate when packaged in a WLCSP and that the bulk of such fan in WLP are projected to be for analog and mixed signal devices.

amkor 1

The main applications for laser in WLP are:

Laser marking

  • Scribe product info on die backside for traceability

–Laser dicing

  • Separate product from wafer form to die form

–Advanced process node low-k wafer (90 nm and below). Delamination can be easy observed by blade saw due to low-k material being more brittle

–Saw street design issues – reduce topside chipping and peeling

–Saw street width shrink – By shrinking saw street width, gross die per wafer would be increased which can reduce unit cost, ex. RF switch, LNA products

amkor 2

Two kinds of laser cut can support saw street width down to 20 μm: Stealth dicing (SD) and full laser cut.

The stealth dicing process is shown below:

amkor 3

The key to full laser cutting is minimizing the HAZ (heat affected zone).

Amkor 4

ITRI – Emerging Trends & Apps for IoT

Ray Yang of ITRI examined the “Emerging Trends and Applications of IoT in the Post Smart Phone Era”. This presentation started with two interesting slides depicting Taiwan’s electronics revenue.

2014 Semi industry ranked first in value-added among Taiwan’s manufacturing sectors. The foundry business contributes the most to the Taiwan IC industry as shown in the breakout below.


Taiwan IC packaging and test accounts for more than half of worldwide assembly and test revenues.


When examining the future of autonomous vehicles he broke out the requirements into the 3 functions: sensing, understanding and action as shown below.


For all the latest in Advanced Packaging, stay linked to IFTLE…


Easily post a comment below using your Linkedin, Twitter, Google or Facebook account. Comments won’t automatically be posted to your social media accounts unless you select to share.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>