What happens in an OSAT Fab

What Happens in an OSAT Fab

This article takes you on a detailed journey inside an OSAT facility, unraveling the complex yet fascinating process of transforming semiconductor wafers into functional integrated circuits (ICs).
Share this STORY


In the rapidly advancing world of electronics, semiconductor devices are the unsung heroes powering our everyday gadgets and technologies. Behind the scenes, there exists a crucial stage in the semiconductor manufacturing process known as the Outsourced Semiconductor Assembly and Test (OSAT). This article takes you on a detailed journey inside an OSAT facility, unraveling the complex yet fascinating process of transforming semiconductor wafers into functional integrated circuits (ICs).

Follow us on Linkedin for everything around Semiconductors & AI

9 key Steps in an OSAT Fab

1. Receiving Semiconductor Wafers:

The journey begins as the OSAT facility receives semiconductor wafers from the semiconductor manufacturing company. These wafers are a hub of potential, housing multiple integrated circuits (ICs) that need to be carefully separated, assembled, and tested.

Read more: Foxconn to Setup an OSAT facility in India with HCL Group

2. Wafer Sawing:

Once the wafers arrive, the first step is wafer sawing. This process involves precision cutting to separate the individual ICs, turning a single wafer into multiple dies.

3. Die Attach:

The separated ICs, now referred to as dies, undergo die attach. This step involves the application of a small amount of adhesive to bond each die onto a substrate or a package, setting the stage for further integration.

Read More: Kaynes Technology to Invest 2800 Cr for OSAT facility in Telangana, India

4. Wire Bonding:

Thin wires become the bridges connecting the die to the package in the wire bonding phase. This meticulous process establishes the necessary electrical connections, allowing signals to flow between the die and the external world.

5. Encapsulation (Molding):

To shield the delicate semiconductor components from environmental threats, the assembly enters the encapsulation phase. The ICs are encapsulated in a protective material through a molding process, ensuring resilience against moisture, dust, and physical damage.

Read More: Explained: What the hell is an OSAT that will create 1000s of jobs in India

6. Testing:

Post-assembly, the ICs undergo a battery of tests to validate their functionality. Electrical tests are conducted to ensure that the semiconductor devices meet stringent performance criteria, guaranteeing their reliability in various applications.

7. Marking and Packaging:

After passing the tests successfully, personnel mark the ICs with essential information, including part numbers and production dates. Following this, they meticulously package the marked ICs into their final form, making them ready for integration into electronic devices.

Read More: What is Profit Margin of Each Player of Semiconductor Value Chain?

8. Quality Control:

Throughout the entire process, quality control measures are implemented to identify and rectify any defects or issues in the assembly. Rigorous quality control ensures that the final products meet the highest industry standards.

9. Shipping:

After completing the assembly and testing phases, the OSAT facility prepares the finished and tested semiconductor devices for shipping. The facility then distributes these ICs to customers, which may comprise electronics manufacturers or companies integrating these components into their products.


The journey inside an OSAT facility is a symphony of precision, technology, and quality control. As semiconductor devices continue to play a pivotal role in our interconnected world, the meticulous processes within an OSAT facility ensure that these components meet the demands of modern technology. From receiving raw wafers to shipping fully functional ICs, every step in the OSAT journey contributes to the seamless integration of semiconductor technology into our daily lives.

Share this STORY

Leave a Reply

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