TRIZ Invention Solutions For
Optimising Production Yield
By Ab. Rashid Omar
Amkor Technology is known as one of the world’s
largest providers in contract semiconductor assembly
and test services. It was founded in 1968 and is wellrecognised as a pioneer of the Integrated Circuit (IC)
assembly and test for outsourcing. Being the largest
semiconductor manufactures in outsourcing services
around the globe, it has also become as one of the
leading technological leaders in semiconductor
manufacturing industry.
The company has established a
strategic manufacturing
partnership with more than 300 of
world’s leading semiconductor
companies and electronic Original
Equipment Manufacturers (OEMs).
Amkor Technology has become
more sustainable in the long-run
through this strategy. This is
supported by the fact of rapid
growth in product development.
Furthermore, Amkor
Technology has also invested
extensively in acquisition of
sophisticated facilities and
advanced technologies. This is an
essential element that brings
Amkor Technology into the next
phase of innovation.
Amkor Technology in Malaysia which is located in
Selangor assists Power Discrete semiconductor
companies with high quality packaging and test
services. Its power discrete centre has more than 40
years of experience with a built up in manufacturing
floor space of 24,155m2 and is accredited by the
Japanese Automotive Certified. Whereas Amkor
Technology Malaysia Sdn Bhd (ATM) was incorporated
in 1973 and has total manpower of 1,800 employees.
ATM produces a wide range of products including
electronic components, integrated circuits and
transistors. As a recognition of its commitment towards
quality and in its pursuit for excellence, ATM has been
awarded with six certifications, namely TS-16949,
ISO-9001, ISO-9002, OHSAS-18001, ISO-14001 and SONY
Green Partner industry standards. This is in line with
its aim to be the Center of Excellence for power
discrete packaging.
Better Yield Leads To Higher Productivity
It is very much believed by ATM that high productivity
will lead to high yield in all level of the production
lines. In addition to this, the management at ATM also
holds on to its belief that ambiance is vital to all
employees. Nevertheless, productivity drives ATM to
adapt the concept of ‘right at the first time’ which is
expected to reduce defect cases in production lines.
At ATM, the reject cases are closely monitored as it
has a significance on the total production output every
month. In addition to this, it was identified that two
crucial aspects in producing output with quality were
high machine efficiency rate and low in Turnaround
Time (TAT).
Consequently, they understand that work efficiency
will eliminate wastages and add value to work process
itself. Therefore, ATM has always promoted innovation
among its employees to ensure their employees are
not left behind and are able to think beyond
boundaries. ATM has paved Innovation and Creative
Circle (ICC) as a platform for the implementation of
ideas working towards a more structural and
systematic work process. Consequently, ATM has
chosen ICC projects to accelerate productivity and
quality, ensure time efficiency and minimise cost of
production.
Implementation Of TRIZ Technique In
Accelerating The Process Of Generating New
Ideas
One of the most essential production lines is DD2B.
DD2B is the process that involves marking and packing
the final products which are placed at the end of the
whole production line. DD2B usually achieved a
performance of 97.8 percent. However, in 2014, it was
identified that DD2B performed below the targeted
yield value of 98.6 percent. This was highlighted by
the management during the monthly division meeting.
The mark/pack workflow
consists of nine processes.
Based on the six month data
(Jan-June 2014) that was
collected, it was recorded that the
number of defects produced was
22,017 pieces per month which
was equivalent to 1.16 percent of
marking defect rate. The
benchmark value for this
rate was 0.36 percent
from IC production line.
In order to overcome the problem, a team of six young
outstanding employees were selected to come up with
a plan. This team which was known as My Team, aimed
to reduce 70 percent of high defect rate which
amounts to 6,605 pieces per month. The team also
targeted to increase yield value rate from 97.8 percent
to 98.6 percent. Following that, the team set an
objective to reduce the appearance defect rate from
142.7kiloRM to 42.8kiloRM by December 2014.
The ICC project started with the process mapping of
mark/pack machine work flow in which helped the
team to understand and identify the root cause of this
issue. The team further used the Fishbone diagram and
Cause & Effect matrix for root causes verification.
Based on the findings, My Team further used 5W+2H
technique and concluded that the problem of high
defects were contributed from the mark/pack
machine. They further learnt that the chuck unit or
mechanical part in the machine was not clamped
to the device properly. This made the position of the
chuck divergent with the device. Furthermore, the
heavy friction movement during clamping has led to an
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unstable slide bearing movement. In addition to this,
the technician had made improper adjustment as
there was no Standard of Procedure (SOP) for
references. Next, was the issue of poor visibility as
there was insufficient lighting. This happened due to
the dust that was accumulated at the lamp surface
which actually prevented adequate lighting. Lighting is
a crucial aspect as the inspection unit needed light for
product inspection. Further studies showed that the
dust accumulated at the lamps was produced during
the daily operations of other functional areas.
However, the air shooter was unable to remove or
clear the dust from the lamp surface.
acronym, for “Theory of Solving Problem Solving”) is a
problem solving and brainstorming technique that has
been growing in popularity, especially among design
engineers. The team applied the six TRIZ inventive
principles and engaged with internal engineers and
specialists. Through this technique, they were able to
derive new, creative and innovative solutions
especially through their exclusive experiences and
knowledge. Furthermore, the team created new
invention of an air shooter design for removing dust
that is accumulated at the lamp surface. The table
below shows the root causes, proposed solutions and
action taken to resolve the problem of high in
appearance defects.
These findings were used by the team to generate
ideas for improvement through several brainstorming
sessions. The team used TRIZ inventive technique to
develop new solution for chuck unit. TRIZ (Russian
Root Cause
Proposed Solution
Action Taken
Chuck Unit did not
clamp the device
properly due to the
chuck position did not
parallel with the device
To change the chuck position from top 1. The team developed new design of
of the chuck table to bottom side of
chuck unit changing from vertical
chuck table (from vertical to
movement to horizontal movement
horizontal movement)
2. A Poka Yoke Jig was developed for :
 Setting accuracy of the position on
clamper
 Setting the gap without device
between chuck base to chuck
clamper
 Standardising all the chucks
alignment
The insufficient lighting
was due to the dust
accumulated at lamp
surface
Redesign the air shooter
3. Changed the old design of single
direction of air shooter to rectangle
block of multiple air shooters that
suitable with the lamp surface area
length
 Seven outlets air shooter with 3mm
diameter each
 300 of angle
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THE NINE PROCESSES IN THE MARK MACHINE
WORKFLOW
TRIZ INVENTION SOLUTIONS
Solutions for chuck unit
1. New design of chuck unit from vertical
to horizontal
Solution to remove dust
3. Rectangle block of multiple air shooters
2. New jig for setting the chuck position
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Three improvements including new design of chuck unit, a poke yoke
jig as well as multiple air shooter aided in achieving the target. The
reduction in defect rate achieved by the team was acknowledged by
the management. As a role model of innovation, My Team has applied
these initiatives to other machine model and other departments as
well. This is to accelerate the process of reducing the defect rate in
other production lines. Thus, it is no doubt that ICC drives an
organisation towards improvement and greater achievements in the
future with the right atmosphere, approach and especially teamwork
spirit.
Analysis Of ICC Project In ATM
Previously, it was recorded that an average of 22,017
pieces with defect were produced in the DD2B
production line every month. After incorporating ICC
initiatives, the team managed to reduce the defects to
6,545 which indicates 70 percent improvement in
defect cases. Not only that, this has brought a positive
impact to the marking defect rate as it has reduced to
0.35 percent from 1.16 percent previously.
Consequently, the yield performance has also
improved to 98.6 percent and the team is able to
reach the target of this ICC project.
My Team also conducted an opinion survey to evaluate
the effectiveness of the project among the team
members. This survey covers six elements which
focuses on teamwork, responsibility, discipline,
confidence, communication and quality control (Likert
scale of 1 to 5). The survey showed that there was an
improvement of 1.17 where the overall evaluation
actually increased from 3.50 to 4.67. This actually
reflects on the motivation among the team members
towards their work spirit. Others benefits are as
follows:
 `Spin-off’ of the improvement items to other
machine model in other departments;
 Standardisation in process flow and schedule of
other machine for part adjustment; and
 Showcases the best practices, in-house
competition, appreciation and innovative
exhibition week
In addition to this, the cost of purchasing parts has
also reduced to RM5,840 as compared to RM17,496
previously. This project also benefitted the company in
terms of cost saving such as labor, machine and
production cost during the implementation stage. The
actual cost saving for this project constituted to
RM421,311. Hence, it is no doubt that ICC initiatives
have succeeded in reducing operation costs, defect
cases and increasing work efficiency which drive
towards output optimisation.
COMPARISON BEFORE AND AFTER ICC IMPLEMENTATION
Number of appearance
defects :
Before : 22,017 pieces
After : 6,545 pieces
Marking defect rate:
Before : 1.16%
After : 0.35%
Yield performance:
Before : 97.8%
After : 98.6%
Cost of parts:
Before : RM17,496
After : RM5,840
Team score:
Before : 3.5 points
After : 4.67 points
Cost saving:
Before : 0
After : RM421,311
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