Encapsulated Type	Trandition Encap (QFP、BGA）	Wafer Level CSP
Advantage	High Process Yield Mature material and equipment	Small Size Avaliable  Low Running Cost Simplfy Process Fine Pitch Avaliable
Disadvantage	Fine Pitch Design Complicated Process  High Running Cost	Less I/O Pin A(<100)

WAFER LEVEL-CSP Flux Stencil

 

• PAD Opening Design： X1: Opening(Upper)，X2=Opening(Lower) / X2 – X1 = 2~6um(Adjustable)
• Stencil Thickness (MF) : MF : 20~100um(Adjustable)
• Tension (N): 20~34N(Adjustable)

WAFER LEVRL CSP - Ball Stencil

• PAD Opening Design： X1 is based on the solder ball size ; X3 – X2 = 2~6um(Adjustable)
• Stencil Thickness (CT): CT:15~30um(Adjustable)
• Metal Foil Thickness (MF1 & MF2) : MF1 : 80~130um(Adjustable) ; MF2:200~250um(Metal or Polymer)
• Tension (N): 20~34N(Adjustable)

The comparsion of inner surface roughness 

Compared FAITHFUL Stencil and Japen Stencil on Opening Dimension.

FAITHFUL's ElectroForming Stencil had better performance than Japen's Stencil.

Compared FAITHFUL Stencil and Japen Stencil on Ink Deposite Performance.

FAITHFUL's ElectroForming Stencil had better performance than Japen's Stencil.

Stencil Application and Surface Technology

 

The Stencil Specification of Wafer Level CSP Application 

Basement Layer
Available Wafer Size	6~12 inch Wafer
Material	NiCo Alloy
Accumulated Accuracy：	+/-0.01%Length
Thickness Range(μm)	20~200
Thickness Accuracy(μm) (Pattern Area)	20~50μm(+/-3μm) 51~100μm(+/-10μm) 101~200μm(+/-20μm)
Minimum Opening (μm)	50μm
Minimum Space (μm)	50μm
Opening Aperture Accuracy(μm)	+/-3μm(Thickness Range：20~50μm) +/-5μm(Thickness Range：51~100μm) +/-5μm(Thickness Range：101~200μm)
Aspect Ratio	≦1:1.2

Support Layer
Material	Polymer or NiCo Alloy
Alignemnet Space(μm)	30μm/side
Thickness Accuracy(Pattern Area)	Polymer：+/-3μm NiCo Alloy：+/-10μm
Minimum Support Area(μm)	40μm×40μm
Minimum Support Width(μm)	40μm×40μm

Product
Aspect Ratio	≦1:1.2
Tension(N)	20~34

The Advantage of FAITHFUL Electroforming Stencil with polymer supporting layer

• High Accumulated Accuracy and Precised Metal Thickness.
• Using polymer supporting layer can make sure excellent stecncil flatness and the uniformity of thickness can below 3μm.
• The charateristic of Faithful electroforming stencil is long life time because we selected the Ni/Co alloy as our soultion basement.
• It can be avoid the wafer damaged issue happen by the stencil we desinged with the supporting layer on the stencil.

Diagram Index

• The space of polymer is  X :50~500μm(Depend on the product design)

Diagram Index

• The space of polymer is  X :50~500μm(Depend on the product design)