Distinction And Connection Between Wafer, Die And Chip

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This article mainly introduces the distinction and connection between wafer, die and chip.

Wafer--Raw Material and Production Platform

Wafers are the basic material for semiconductor manufacturing and are typically made of high-purity silicon (Si) or other semiconductor materials. The shape of the wafer is generally a round sheet, the thickness is generally between a few hundred microns and a few millimeters, and the surface has been carefully treated to make it smooth enough and has an excellent crystal structure, which is suitable for the processing of various electronic devices.

Analogy: A wafer can be compared to a "raw material" or "paper", similar to the paper on which we make a book, which is not the final product in itself, but it is the basis of all subsequent processes.

Die -a single circuit unit that has been segmented‍

On the wafer, after a series of semiconductor processes (such as lithography, doping, etching, etching), a large number of integrated circuit structures will be formed. Each individual unit in these integrated circuit structures is called a die. Die is obtained by cutting the wafer into small pieces, each representing a complete electronic assembly, usually fully functional, but not yet encapsulated at this stage.

Metaphor: A grain can be compared to "a single article on the page." It is a small part cut out of the "whole book", and each "article" has its own content and function, but it is not yet complete, and has not yet added steps such as cover, binding, etc.

Die shapes are typically rectangular or square, and the specific requirements for size and shape will vary depending on the product's design, functional requirements, and manufacturing process. The quality of the die directly affects the quality of the final chip, so the die needs to be rigorously tested and screened during the production process (e.g., KGD: known good die that meets functional and reliability requirements).

Chip-The finished product after packaging

After the die is cut and tested, it is packaged into a complete chip. The package not only provides physical protection for the die from damage during use, but also connects the chip to external circuitry through pins, pads, etc. A chip is the final user- and market-oriented product, and it is only after the chip is packaged that it has the actual electrical function and can be used as part of an integrated circuit (IC) in a variety of electronic devices.

Metaphor: A chip is like a printed and bound book. Each article (chip) is integrated into a complete book (die) and has a cover and table of contents (package) so that the reader (the system) can use the content of the book (chip).

Wafer, die-to-chip relationships

Wafers are the raw materials for production, and after a delicate process, many grains are formed.

Die is a separate unit cut out of a wafer, and each die can perform a specified function independently. They often need to be tested to ensure that they are good (e.g., KGD grains) and that they meet electrical performance and reliability requirements.

The chip is the final product that is die encapsulated, with a complete external interface to connect and work with other electronic devices.

The relationship between these three can be understood through a step-by-step process of processing: from the bulk of the raw material (wafer), to the cutting into small units (die), to the packaging into the final product (chip), each step is crucial and determines the quality and functionality of the final chip‍