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Assembly and Packaging (Part 1)
Chapter 20 : Semiconductor Manufacturing Technology by M. Quirk & J. Serda
Saroj Kumar Patra,
TFE4180 Semiconductor Technology,
Norwegian University of Science and Technology ( NTNU )
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Objectives
• Describe the general trends and design constraints of
assembly and packaging.
• State and discuss the traditional assembly methods.
• Describe the different traditional packaging options.
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Introduction
• Final assembly and packaging, the back-end of the IC
manufacturing process
• Two distinct processes
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Traditional Final Assembly and
Packaging Process (Encapsulation)
Wafer test and sort
Wire bond
Die Separation
Plastic packaging
Die Attach
Final packaging and test
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Four Important Functions of IC Packaging
1.
2.
3.
4.
Protection from environment and handling damage
Interconnections for signals into and out of the chip
Physical support of the chip
Heat dissipation
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Dual in-line package
(DIP)
Quad flat pack
(QFP)
Single in-line package
(SIP)
Plastic leaded chip carrier
(PLCC)
Thin small outline package
(TSOP)
Leadless chip carrier
(LCC)
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Design Constraints for IC Packaging
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Levels of IC Packaging
1st level packaging:
IC-packaging
Metal leads for mounting
onto printed circuit board
Leads
2nd level packaging:
Printed circuit board (PCB)
assembly
Surface
mount chips
are soldered
on top of
copper pads
ont the PCB.
Pins
Pins are
inserted into
holes then
soldered on
rear of PCB.
Edge connector plugs into main system
PCB subassembly
Final product assembly:
Final assembly of circuit
boards into system
Main electronics
assembly board
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Traditional Assembly
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Four Steps of Traditional Assembly
•
•
•
•
Backgrind
Die separation
Die attach
Wire bonding
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Backgrind
Downforce
Rotating and
oscillating spindle
Wafer on
rotating chuck
Table rotates only during
indexing of wafers
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Advantages of Thinning Wafers
•
•
•
•
Thinner wafers are easier to dice into chips
Improved thermal dissipation
Reduces thermal stresses in thin ULSI packages
Thinner chips reduce the size profile and weight of
the final IC package
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Die Separation
Wafer
Stage
Blade
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Die Attach
Lead Frame
Lead
Die
Plastic DIP
- Selected die is attached
- Automated process
http://www.youtube.com/watch?v=syMdS02P3_w
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Different Methods of Die Attaching
• Epoxy attach
• Eutectic Au-Si attach
• Glass frit attach
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Epoxy Attach
Chip
Epoxy
Lead Frame
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Eutectic Au-Si Attach
Gold/Silicon
eutectic alloy
Silicon
Gold Film
Lead Frame
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Glass Frit Attach
Mixture of silver and glass
particles suspended in an
organic medium
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Wire Bonding
Electrical connection from chip surface to inner lead terminal
http://www.youtube.com/watch?v=VwOEQodkBrY
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Wire Connection Between Bonding
Pad and Lead Frame
Die
Moulding compound
Bond wire
Bonding pad
Leadframe
Pin Tip
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Different Methods of Wire Bonding
• Thermocompression bonding
• Ultrasonic bonding
• Thermosonic ball bonding
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Thermocompression Wedge Bonding
Heat
Pressure
Leadterminal
Device Bond pad
Wedge bond
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Ultrasonic Bonding
Ultrasonic energy
Tool moves upward
Wedge tool
Wire fed
Pressure
Wire
Al bonding
pad
Die
(1)
(3)
(2)
Ultrasonic energy
Pressure
Tool moves upward
Wire Breaks
Lead Frame
(4)
(5)
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Ball Bonding
Gold Wire
Capillary tool
Pressure +
Ultrasonic energy
Bonding ball
on
pad
Die
H2 Torch
Die
Ball
(1)
(3)
(2)
Pressure and heat
Lead Frame
(5)
Tool moves
up
Wire Fed
(4)
Tool moves upward
Wire Breaks at
the bond
(6)
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Comparison Among Methods
Type
Pressure Temperature
Ultrasonic
energy
Wire
Pad
Au,
Al, Au
Thermo
Compression
High
300-500 oC
No
Ultrasonic
Low
25 oC
Yes
Ball bonding
Low
100-150 oC
Yes
Au, Al Al, Au
Au
Al, Au
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Wirebond Quality Measuring
• Visual inspection
• Pull test
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Visual Inspection
•
Used to detect wirebonding failures
Wire broken
Wire missing
Ball short circuit
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Pull Test
•
Quantitative assessment of wirebond quality
Hook
Terminal
Device
Chip under test
Holder
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Traditional Packaging
• Metal packaging
• Plastic packaging
• Ceramic packaging
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Metal Packaging
• Was common in early history of Semiconductor industry
• Still used today in special cases
Gold‐plated header
Die
Wirebonds
Leads
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Transistor Outline (TO) Type Metal
Package
Laser diode
in TO39 package [1]
Voltage regulator
in TO3 package [2]
Used for packaging this type of devices:
•
•
•
•
Semiconductor lasers, solid-state lasers with a diode pumping
Photodetectors, matrix photodetectors (CCD, FPA)
X-Ray detectors
Transistors, operational amplifiers, etc.
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Plastic Packaging
•
Industry mainstay since its introduction
•
Highly popular due to:
o flexibility of the lead shape (gull-wings, J-leads, PIH)
o high volume production techniques
Die
Leadframe
Leadframe [3]
Tie bar
Tie bar removal
lines
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Plastic Packaging
Packaging procedure
•
•
•
•
Molding
Deflashing
Component lead forming
Lead finish
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Plastic Dual In-Line Package (DIP)
A type of through-hole mount package with lead pins
protruding from both sides of the package.
DIP20 package [4]
DIP6 package [5]
Used for packaging this type of devices:
Microcontrollers, logic elements, memory, operational amplifiers,
buffers, optocouplers, timers, signal generators, etc.
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Single In-Line Package (SIP)
A single row of leads protruding from the bottom of its body.
SIP's are often used in packaging:
• networks of multiple resistors
• single on chip amplifier solutions
• voltage regulators
Power controller in SIP package [6]
Audio power amplifier in SIP package [7]
Resistor network in SIP package [8]
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TSOP with Gull Wings
TSOP - Thin Small Outline Package
Gull Wings – shape of the pins
•
•
•
•
Low profile
Tight lead spacing
High pin count
Used for surface mount
SDRAM [9]
DRAM [10]
TSOPs are often used in packaging memory modules
(SRAM, Flash memory, FSRAM and E2PROM)
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QFP with Gull Wing and
Surface Mount Leads
• QFP – Quad Flat Pack
• Socketing such packages is rare and
through-hole mounting is not possible.
• Used for packaging memory, processors,
controllers, ASIC, DSP, etc.
80‐pin Microprocessor in TQFP package [12]
TQFP ‐ Thermally Enhanced
package [11]
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PLCC with J-Leads
•
PLCC - Plastic Leaded Chip Carrier
•
Used for surface mount
•
Used for packaging memory, processors, controllers,
ASIC, DSP
PAL from TI
in 28 pin package [14]
EEPROM from ALTERA [13]
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Leadless Chip Carrier (LCC)
•
Available in plastic and ceramic packaging
•
Used for packaging CMOS image sensors, MEMS,
crystal oscillator filters, antenna switch modules
LCC from Tektronics [15]
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Ceramic Packaging
Used for the state of the art devices that require:
• maximum reliability
• high-power
• hermetic seal
Two main methods of ceramic packaging:
• Refractory ceramic (used for high performance IC packaging)
• Laminated ceramic (low cost approach used to create CerDIP package)
OpAmp from AD in CerDIP package for use in harsh environment [17]
CPGA [16]
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g{tÇ~ lÉâ
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References
[1] http://www.thorlabs.com/images/large/21973‐lrg.jpg
[2] http://media.digikey.com/photos/Texas%20Instr%20Photos/296‐TO‐3‐8.jpg
[3] http://www.ue.com.hk/index.php/SOIC_%28Small_Outline_Integrated_Circuit_Packages%29
[4] http://www.chinaicmart.com/uploadfile/ic‐doc/261‐20‐DIP.jpg
[5] http://media.digikey.com/photos/Fairchild%20Semi%20Photos/46‐6‐DIP%20WHITE.jpg
[6] http://www.infineon.com/cms/en/corporate/press/news/releases/2009/INFXX200906‐063.html
[7] http://sjostromaudio.com/pages/hifi‐projects/36‐hifi‐projects/82‐qrp01‐the‐gainclone‐high‐performance‐power‐
amplifier?showall=1
[8] http://www.emartee.com/product/41417/Resistor%20Network%2010K%20OHM%209P%208RES%20SIP
[9] http://rocky.digikey.com/weblib/Micron/Web%20photos/557‐86‐TSOP.jpg
[10] http://s.eeweb.com/resized/images/remote/http_s.eeweb.com/quizzes/2011/02/22/dram‐tsop‐
1298440075_500_327.png
[11] http://www.analog.com/en/technical‐library/packages/qfp‐quad‐flat‐pack/tqfp‐thermally‐enhanced/index.html
[12] http://en.wikipedia.org/wiki/File:PIC18F8720.jpg
[13] http://ca.digikey.com/1/1/1042179‐ic‐max‐7000‐cpld‐64‐68‐plcc‐epm7064lc68‐15.html
[14] http://media.digikey.com/photos/Texas%20Instr%20Photos/296‐28‐PLCC.jpg
[15] http://component‐solutions.tek.com/services/ic‐packaging/packaging‐tech/#leadless‐chip‐carrier
[16] http://www.interfacebus.com/ic‐package‐Ceramic‐PGA‐package‐dimensions.html
[17] http://www.analog.com/en/technical‐library/packages/dip‐dual‐inline‐package/cerdip‐side‐or‐bottom‐
brazed/index.html
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