Semiconductor Back-end Subcontractors


Disclaimers:  We constructed this page merely in response to numerous requests from our readers to feature the various semiconductor assembly and test  subcontractors in existence today.  The information contained in the following sections were all taken from the internet, and are therefore limited in content and scope, and possibly not current as well.  Furthermore, all descriptions pertaining to each of the subcontractors were lifted directly from the subcontractors' respective websites, with minimal editing on our part, if at all.  We are not making any endorsements for and on behalf of any of these subcontractors, and will not be responsible for any effects that use of the following information will have on any entity.  Readers are advised to visit the websites of these subcontractors if they need more information.






Amkor is a strategic contract manufacturing resource for many of the world's leading semiconductor companies. They have developed unique expertise in high-volume manufacturing techniques and have diversified and expanded their operational scope by establishing production centers in strategic locations throughout Asia.


Amkor provides leading-edge package solutions such as Stacked Packaging, Flip Chip, MicroLeadFrame, System-in-Package, Image Sensors, MEMS, and MMC / SD for latest generation applications.


Amkor supplements its world-class operational scope with the industry's largest package design staff, broadest portfolio of packaging technology, deepest sales and support organization.


As integrated circuits increase in speed and complexity, the right semiconductor packaging becomes critical to ensure optimal system performance. Amkor is an industry leader in tailoring application-specific package design, assembly and test solutions.


Amkor offers the industry's broadest array of package formats and sizes, from traditional, "off-the-shelf" leadframe configurations to leading-edge chip scale, flip chip and system-in-package solutions incorporating highly customized designs. This allows Amkor to be a single source for many of our customers' total IC packaging requirements.


Amkor also provides a complete range of test engineering services for RF, mixed signal, logic and memory devices, from test program development to full product characterization. Amkor is a major provider of RF test services and is the world leader in Strip Test, an innovative, highly parallel test solution that offers customers low cost, faster index time and improved test yields.


With Amkor providing turnkey solutions that include semiconductor design, packaging, test and drop-shipment services, our customers can get accelerate time-to-revenue for their new products.


Amkor collaborates with customers and leading OEMs to develop comprehensive package solutions that make it easier for next-generation semiconductors to be designed into next-generation end products. By sharing device, package and product roadmaps we enable our customers - and their customers - to accelerate the development and deployment of new microelectronic applications.


Focusing on our core competencies allows our customers to optimize their assets and reduce time-to-sales.


Table 1.  Packages Offered by Amkor as of October, 2004

Advanced Product Development

Stacked CSP

Ultra CSP™ Wafer Level Packaging

Game, Memory and I/O Cards (AmKard™)

Small Form Factor Memory Cards (SFFMC)


System in Package Module

Image Sensor / Optical

VisionPak® LCC

Image Sensor Camera Module



ChipArray SON (CASON)


Enhanced BGA (EBGA)


Flip Chip CSP (fcCSP) High Performance BGA (HPBGA)





Super Flip Chip (SuperFC®)

Thermally Enhanced PBGA (TEPBGA)



TapeArray® BGA




ExposedPad™ LQFP / TQFP

ExposedPad™ SOIC / SSOP

ExposedPad™ TSSOP


LQFP PowerQuad® 2

LQFP PowerQuad® 4

Multi-Chip & Stacked Leadframe

MicroLeadFrame® (MLF)


MQFP PowerQuad® 2

MQFP PowerQuad® 4



PSOP 2 & 3 / PSSOP


SOT-23 / SC-70





Ceramic / Hermetic










Flat Pack



Side Braze

Other Package Types We Offer




As the demand for outsourcing continues to grow and supply chains continue to shorten, Amkor is committed to increase our role in the customers' value chain. To this end, Amkor offers a full line of value-added services.


By becoming involved in the customers' projects as early as possible, Amkor feels they can add benefits such as Electrical Package Characterization and Thermal Package Characterization. Using these two Amkor specialized services, customers can better understand how their device will react both electrically and thermally once it inside a finished package. Knowing this at the beginning of the design phase helps designers make better decisions for a superior performing end product.


Getting involved at the die design phase also allows Amkor's Packaging Design Center to create the optimum package for any device. Our design experts can advise on how specific aspects of the device will interact with a given package design to help optimize the device performance.


Adding to this, Amkor has the expertise and experience to provide probe or test solutions for the entire spectrum of integrated circuits through our many Test Services facilities. Located worldwide for customer convenience, Amkor offers test services for any device, from simple digital logic, complex ASIC, high speed digital, memory, mixed signal and RF/Wireless devices.


These services along with several others such as Die Processing, Package Signal Integrity Analysis, Failure Analysis, Qualification Testing, Engineering Support and an Online Customer Center combine to make Amkor a valuable link in the customers supply chain.


Table 2. Amkor's Manufacturing & Test Facilities as of October, 2004


Amkor’s C1 factory in Shanghai China is ISO-14001, ISO-9002, QS-9000, and ISO-9001 certified. Our 150,000 square foot facility offers a range of laminate and leadframe packages, including Chip Scale BGA, Stacked packages, System-in-Package, SOIC and TSOP. Located in the Waigaoqiao Free Trade Zone, where we are surrounded by many major semiconductor companies, Amkor China offers leading-edge package and test technologies to support the rapidly growing China market. Click here for additional information on Amkor Technology China (ATC).


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Operating Focus



Manufacturing (Turnkey: Probe, Assembly and Test), R & D, and Distribution



Amkor entered the Japan market in 2001 with a 143,000 square foot factory located in Kitakami, Iwate. Our direct manufacturing presence in Japan allows Amkor to better serve the Japanese market with quick turn, high quality packaging and test services. Our Iwate factory offers Japanese semiconductor companies a broad range of laminate and leadframe packages, including BGA, Chip Scale BGA, Stacked packages, Wafer Level CSP and MicroLeadFrame ®.


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Operating Focus



Packaging Services, Wafer Test, Test Services, Backgrinding Services



South Korea is the home to three Amkor factory locations and over 2 million square feet of manufacturing capacity. All locations are ISO-9002, QS-9000, ISO-14001 and ISO-9001 certified and offer high quality packaging and test services supporting worldwide markets.


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Operating Focus



Packaging Services, Package & Process Development, and Backgrinding Services



Packaging Services, Test Services and Backgrinding Services



Packaging, Services, Test Services, Backgrinding Services and Wafer Bumping Services



The Philippines is the home to four Amkor factory locations and over 1.3 million square feet of manufacturing capacity. These factories provide a full line up of services including leadframes, laminate, ceramic and System in Package packaging and test, wafer probe, burn-in, strip test, tape and reel and direct shipping. All locations are ISO-9002, QS-9000, ISO-14001, ISO 9001 and DSCC / QML certified and offer high quality packaging and test services, with more than 1000 test systems, supporting worldwide markets.


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Operating Focus

P1 / P2


Packaging, Test, and Process Development Services

P3 / P4


Packaging and Test Services




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Operating Focus



High-end Test (Logic and Mixed-Signal) Services



Amkor entered the Taiwan market in 2001 and provides Taiwan semiconductor companies and IC design housles with a broad range of packaging capabilities, including flip chip, TSOP, TQFP, LQFP, SOP, PBGA, CABGA, VisionPak, Green Packaging, and MEMS. Amkor factories are located near Hsin Chu Science Park offering easy access to foundries and customers.


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Operating Focus



Packaging Services, Test Services, and Backgrinding Services



Flip Chip Packaging and Test Services


United States

Amkor Test Services in Wichita, Kansas is a testing facilitiy that supports final test, wafer probe, test software development, qualification and temperature upscreening test services on integrated circuits. This facility is ISO-9001, AS9100, DSCC MIL-PRF-38535 and MIL-STD-883 certified.

Amkor Test Services in Santa Clara, California is a testing facility that supports ESD Evaluations and Latch-up test services on integrated circuits. This facility is ISO-9001 certified.


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Operating Focus



Test Services



ESD and Latch-up Test Services


Unitive, An Amkor Company


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Operating Focus



High-end Test (Logic and Mixed-Signal) Services



Wafer Bumping Services





ASAT Holdings Limited is a global provider of semiconductor assembly, test and package design services. With 15 years of experience (as of 2004), the Company offers a definitive selection of semiconductor packages and world-class manufacturing lines. ASAT’s advanced package portfolio includes standard and high thermal performance ball grid arrays, leadless plastic chip carriers, thin array plastic packages, system-in-package and flip chip. The Company has operations in the United States, Asia and Europe. ASAT Inc. is a wholly owned subsidiary of ASAT Holdings Limited and the exclusive representative of services in North America.
Peak Performance Initiative

CEO Harry Rozakis launched ASAT's Peak Performance Initiative to drive ASAT to become the leader in advanced semiconductor package development, by setting industry standards for acceptance, performance, reliability, and time-to-revenue. ASAT created quantifiable goals on a department-by-department basis, with supporting benchmarks designed to deliver lower costs, lower risks and higher profits for both customers and the Company.


Table 3. ASAT's Products as of October, 2004

Featured Product

ASAT introduces the Thin Array Plastic Package, a Revolutionary New Concept of Leadless Technology. ASAT's TAPP™ is a leadless, Pb-free and multi-row packaging solution. The very thin, fine-pitch package with an exposed die attach pad allows for improved thermal performance and a power/ground ring option for enhanced electrical characteristics. The TAPP offers a superior solution for high-performance and chip scale applications.

Leadless Products

The Leadless section contains formats in QFN single row IO and QFN multiple row IO's products. Also available in SiP, MCM (Multi Chip Modules) and Stacked Die product configurations.

Array Products

The Array section contains Standard Array, Thermally Enhanced, Flip Chip, Stacked Die, SiP and MCM product configurations.

Leaded Products

The section contains Standard Leaded, Thermally Enhanced, Stacked Die, MCM and SiP products configurations.

Flip Chip

As performance requirements, such as high-speeds, smaller IC footprint, increased I/O, and bump densities, continue to drive flip chip technology forward, ASAT, with its leading edge approach to packaging and diversified customer base, will continue to advance its flip chip capabilities. ASAT's flip chip experience and technological expertise will help you sort through the wide variety of available substrate technologies and materials to determine the most efficient technology for your application.

System-in-Package (SiP)

With its core competencies in advanced package design, assembly processes and packaging, ASAT is uniquely qualified to meet the electronics industry's demand for higher levels of integration, cost effectiveness and better electrical performance. Using state-of-the-art design tools, one or more ICs, passive components and discrete devices can be designed into a standard or custom package. These elements can be electrically interconnected to the substrate in both chip form (wire bond or flip chip options available) and pre-tested assembled monolithic packages.


In 2001, ASAT introduced the development of its MSL-1 process resulting in unlimited shelf life for all lead frame-based products. MSL-1 is the JEDEC standard J-STD 020 which guarantees unlimited shelf life for packages stored at standard temperature in an uncontrolled environment. As a result, the baking process step, often required prior to mounting the package on a board or module, is eliminated. This new development will have significant economic benefits for the end user equipment manufacturer.


ASAT is a leading global provider of semiconductor assembly, test, and package design services. With almost 15 years of experience, and a reputation as a leader in advanced packaging technology, the Company offers a definitive selection of semiconductor packages and specialized services including test, design and analysis.


Table 4. ASAT's Services as of October, 2004


ASAT's test capabilities include mixed-signal, RF, and high-speed digital, with linked operations in the U.S. and Asia, featuring ISDN lines for program and data transfer.


The Company's electrical and thermal engineers are masters of analysis and provide a variety of measured or modeled data for any ASAT package.


ASAT provides state-of-the-art packaging design tools and highly qualified engineers required to support all types of substrate, lead frame, flip chip, and modular package designs.





ASE Inc. provides a complete solution of semiconductor backend manufacturing services to its customers, including front-end engineering testing, wafer probing, final testing of logic, mixed signal, and memory semiconductors, and her test-related services. Its testing services employ technology and expertise that are among the most advanced in the semiconductor industry.

ASE Inc’s comprehensive manufacturing and service capabilities enables it to offer customers a high degree of flexibility and efficiency. They provide worldwide customers with engineering test, package and substrate and design, manufacturing, assembly, wafer probing, final test and design manufacturing services (DMS).

Leveraging its own core competencies, ASE addresses the backend challenges of increased product sophistication of systems, and the burgeoning capital requirements off advanced 300mm backend packaging and test functions.

With its flagship manufacturing facilities located in the heart of the world’s leading semiconductor manufacturing center – known as the Taiwan Cluster, it leverages strategic partnerships with the world’s largest wafer foundries TSMC and UMC. This enables its customers to take advantage of the fully integrated front and backend semiconductor manufacturing services offered in Taiwan.

Table 5. ASE's Products and Services as of October, 2004


ASE offers a full range of assembly services for a wide variety of end applications. It is the industry leader in fine-pitch wire bonding with the world’s largest capability. It holds patents for tri-tier fine-pitch technology, and is ramping up quad-tier capabilities. It currently has more than 5,000 wirebonders in service, of which over 3,400 have fine-pitch bonding capabilities.


ASE is the only assembly and test service provider with a sizable substrate operation. And with substrates becoming an increasingly important factor in the IC packaging process, it is aggressively expanding substrate manufacturing. Taking advantage of ASE’s state-of-art in-house substrate capabilities, customers will be able to significantly reduce their costs and their cycle times.

ASE has the capacity to supply laminate substrate for wire bonding innovations, as well as the build-up substrate for flip chip technology. With aggressive expansion plans in place, ASE is committed to doubling its substrate services capacity in the Shanghai facilities.


ASE is the clear leader in test service market share, front-end engineering test, multi-platform testing and test program conversion. It maintains more than 1,200 test systems, including the Agilent 93000, Teradyne Tiger, etc. It is also the largest probing service provider with a capacity approaching 80,000 wafers per month. ASE Group member ISE Labs has the largest engineering test customer base in Silicon Valley.

Design Manufacturing Services

Rounding out ASE’s complete service solution set are turnkey Design Manufacturing Services (DMS) – the final step that brings your sub-assemblies to the marketplace. Here again, ASE facilitates lower costs and shorter cycle times by deploying its module capabilities in Shanghai and Shenzhen, China, close to major manufacturing centers.



ASE operates a number of testing and packaging facilities in Taiwan, Malaysia, South Korea, Japan, Singapore, China, Hong Kong, and the United States. Its facilities provide various types or levels of services with respects to different end-product focus, customers, technologies, and geographic locations.

ASE has sales offices in the United States, Europe, Asia Pacific, and Japan. 




Established in 1971, OSE has been committed to providing a broad range of high value-added IC packaging and testing services and Electronics Manufacturing Services (EMS/CEM), enabling customers to maximize and optimize their resources and apply their core strengths in research and development (R&D), design, and marketing.

OSE draws on its core competence in the innovation of the manufacturing process, information technology, and business workflow to offer a wide range of services to large international corporations. We pay special attention to quality control, cost structure, production capacity, timely delivery, and global logistics. By providing quality services, OSE seeks to establish long-term partnerships with its clients.

Understanding the demands of the future, OSE combines 30 years' experience with unrivalled research and development resources to deliver the latest high performance solutions to customers across the globe. From lead frame IC assembly and test, through to advanced Flip Chip and CSP technologies, OSE is clearly the market leading solutions provider.

OSE offers IC package design and fabricates a full array of packages, with pin counts from 8 to more than 830. It also offers comprehensive IC testing capabilities that verify function availability of product for customers.


Table 6. OSE's Assembly Products and Services as of October, 2004

Leadframe Packages:

Quad Flat Packages (LQFP, TQFP)
Small Outline Packages (SOP, SSOP, TSOP, TSSOP)

Advanced Packages:

Ball Grid Arrays (PBGA, TEBGA, MCM, MCP)

System in Package (SiP):

System in Package is a combination of one or more wire bonded or flip chip die with one or more passive components attached to a standard formal microelectronic package. The package forms a functional block or module that can be used as an assembled module in board level manufacturing.

Green Packages:

In front of environmental awareness and government legislations, OSE migrates to lead-free and halogen-free packaging strategies, universally known as Green Packaging.

Assembly Services:

Wafer Probe, Backgrinding, Full Assembly and Test, Dry bake, Burn-in and Drop-shipment



OSE's Testing Services

Besides a variety of packaging services, OSE also offers comprehensive IC testing capabilities that verify function availability of logic, memory, analog, mixed signal and RF devices for customers.
Established in 1971, OSE began providing testing service to customers as early as 1975. OSE testing services include wafer probe, function test, test program development, loadboard design and burn-in, etc. The 256,200 sq. ft. new testing building will start operation in 2002. This facility will expand testing capacity to 7 times, its present value in terms of floor space. Combined with more than 100 experienced testing engineers and 130 testing systems, OSE is fully capable of being your testing foundry. The prominent turn-key service from OSE will shorten cycle time in the back-end process to provide its customers with a high quality and fully-functional product.





SPEL Semiconductor Limited is the leading one-stop turnkey Wafer Sort, IC Assembly & Test subcon facility in India. Established in 1988 and headquartered in Chennai, SPEL had been serving the local market from 1988 to 1994. Having established a track record at home, SPEL turned its attention to the more demanding global market in 1995. It has since been exclusively serving the Silicon Valley and other parts of the world for over 9 years now. 


As a specialty, SPEL offers onsite & offshore Test Engineering support to Customers. SPEL ensures better interaction & services to Customers through a Sales & Technical support office based at Santa Clara, USA.


The 3C's - Competence, Cost-Effective and Convenience - are the guiding philosophy and building blocks on which SPEL was built and is continuing to grow.


SPEL is highly cost-effective owing to the tax-free income permitted by the Government of India and the abundant availability of well-qualified personnel at economical costs.


Table 7. SPEL's Assembly Facility as of October, 2004


Chennai, India

Floor Space

13,000 sq.ft.


Temperature (°C) 23 + / - 2

Humidity (%) :  55 + / - 5

Class 10,000 Clean Room

ESD Controls

Static Dissipative Flooring

Wrist Straps

Grounded Equipments

Conductive Shoes


Table 8. SPEL's Test Facility as of October, 2004


Chennai, India

Floor Space

5,000 sq.ft.


Temperature (°C) : 23 + / - 2

Humidity (%) :  55 + / - 5

Class 100,000 Clean Room

ESD Controls

Static Dissipative Flooring

Wrist Straps

Grounded Equipments




ST Assembly Test Services (STATS) provides convenient one-stop assembly and test services to customers worldwide. A member of Singapore Technologies, STATS has headquarters in Singapore with offices in Milpitas, CA; Boston, MA; and Tempe, AZ. The Company has approximately 1,000 employees.




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