Design rules

There are a number of conditions that must be taken into account for the etching process.

Material thickness

  • Standard 0.003 - 1.5 mm.
  • Titanium standard up to 0.5 mm.
  • Other thicknesses subject to agreement.

 

Dimensions

  • Standard up to 550 x 550 mm (gross).

  • Larger dimensions subject to agreement.


Tolerances

  • Standard +/- 10% of the material thickness with a minimum of +/- 0.01 mm.
    This however can vary dependable upon material and configuration.
  • Special hole tolerances, for example H7, are normally etched undersize so they can be reamed to size.
  • Nominal dimensions are always assumed.

 

Dam and slot width

  D = dam S = slot/hole damsleuf
iron, carbon steel, stainless steel etc. 1 T 1,2 T
nickel 1,25 T       1,5 T
copper, bronze, brass, beryllium copper etc.   0,8 T 1,1 T
Gold 1,5 T 2 T
Aluminium
1,3 T
1,5 T
molybdenum, silver 0,8 T
1,1 T
Titanium
1,25 T
1,5 T


The minimum feasible dam and slot width is largely determined by the material thickness as follows:

  D = dam S = slot/hole
< 0,1 mm 1,2 T 1,2 T
0,1 - 0,2 mm   0,1 mm 1,1 T
> 0,2 mm 0,15 mm    1 T


Inner and outer corner radius

  R1 R2 hoekradius
< 0,1 mm ≥ 0,75 T    ≥ 1 T   
0,1 - 0,2 mm   ≥ 0,75 T ≥ 1 T
> 0,2 mm ≥ 0,75 T ≥ 1 T


Etching profiles

biconvex biconcaaf diepteetsen convex spits
biconvex biconcave depth etching convex tapered

 

Connection tabs 

  • Photo etching is done in sheets in which product can be configured loose or fixed with connection tabs.
  • Preferably etched will be with connection tabs: this is more efficient and gives a better dimensional accuracy. 

    tab1

    tab2

    afbreekpootje tabel
  • When connection tabs are not desirable loose etching is possible. This is however more laborious and gives less dimensional accuracy.