# Ch-7, Manufacturing in the twenty-first century:micromachining, generatice manufacturing, and self assembly¶

## Problem 1 on page no. 432¶

In [1]:
# Given that
F = 4e-6 # Maximum feature dimension in meter
t = 5e-6 # Photorist thickness in meter
g = 25e-6 # Allowable gap between the mask and the resist meter
lamda = (F**2)/(t+g)
print "Maximum allowable wavelength of the exposing light = %d nm"%(lamda*(10**9))

Maximum allowable wavelength of the exposing light = 533 nm


## Problem 2 on page no. 440¶

In [2]:
from __future__ import division
from math import exp
# Given that
d = 5 # Diameter of hole in micro meter
h = 100 # Depth of hole in micro meter
t = 31.58*(d*(exp(h/(60*d))-1))
print "Time required to machine the hole = %0.1f min"%(t)

Time required to machine the hole = 62.5 min


## Problem 3 on page no. 448¶

In [3]:
from math import sqrt
# Given that
J = 2 # The threshold value of dose in kJ/cm**3
h = 300 # Height in micro meter
J_o = J*(exp(0.1*sqrt(h)))
print "The minimum level of exposure of the PMMA surface = %0.1f kJ/cm**3"%(J_o)

The minimum level of exposure of the PMMA surface = 11.3 kJ/cm**3