Porous vacuum chuck

Porous vacuum chucks – types of chucks

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Types of porous vacuum chucks

Several types of porous vacuum chucks are available today on the market: cylindrical porous chucks, push-up table porous chucks, heater table porous chucks, built-in heater porous chucks among others. Different applications require different types of porous chucks.

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Porous vacuum chuck structure

STRUCTURE

Chuck adsorption surface with flatness below 5µm allows a perfectly stable work platform. Depending on the body shape and other conditions, it is possible to create a porous surface with flatness under 3µm. The chuck is made up by a metal body matched with a porous substance

POROUS MATERIAL

(usually, ceramics) which constitutes the base supporting the substrate. By applying a negative pressure behind the porous layer, it is possible to create a very stable platform that holds the substrate firmly. A vacuum pump placed behind the porous literally sucks the air through the pores creating a very uniform negative pressure.
Chuck adsorption surface with flatness below 5µm allows a perfectly stable work platform. Depending on the body shape and other conditions, it is possible to create a porous surface with flatness under 3µm

Conditions applicable to porous vacuum chucks

Porous vacuum chucks differ by shape, size, type of porous material, material of the body, surface treatment of the body, Diameter of the porous holes and other factors

Proposals according to customer expectations and required applications

• Shape

  • rounded
  • squared
  • cylindrical
  • special shape
• Material of body

  • stainless
  • titan alloy
  • aluminium
  • ceramics

  
  
• Size

  • rounded shape (φ5mm~φ500mm)
  • squared shape (φ5mm~φ350mm)
• Body surface treatment

  • fluorine resin processing
  • anodized aluminium
  • anti-rust coating process
  • electroless nickel plating
• Porous material

  • ceramic
  • conductive ceramics
  • special material
• Porous hole diameter

  • 3µm~580µm

Porous vacuum chuck fabrication workflow

In order to successfully fabricate a good porous chuck, it is necessary to choose the right combination of body material, shape, working temperature and porous material (specification, features). For the porous layer usually alumina ceramic is used, for special applications carbon, super-hard, conductive ceramic material can be used. For the body: SUS, aluminium, ceramic material, titanium and other materials can be used. The porous layer is polished down to a flatness of few µm, with the step between the body and the porous surface reduced to zero.

Porous vacuum chuck fabrication workflow

Typical applications for porous vacuum chucks

Porous chucks are indispensable parts of semiconductor world. Polishing, dicing, bonding and others are among the processes that require very thin wafers to be secured firmly to a piece of equipment. Recently, new applications in the thin-film solar panel, nanoimprint are entering the spotlight. Other applications include laser fabrication of metal and resin and printing.

Adsorption power

 

The two graphs show the adsorption power of Yoshioka chucks.　with the adsorption power of more than 50N, the substrate is being hold firmly

Recover a damaged chuck!

It is possible to recover a damaged porous vacuum chuck in respect of damage occurred because of dirt or stracthes from other material