def SC70(profile, num_pins):
"""Construct a land pattern for an SC70 device.
Supports 5, 6 and 8-pin devices, with dimensions from JEDEC
MO-203.
"""
A = ipc.Dimension.from_nominal(1.25, 0.15)
B = ipc.Dimension.from_nominal(2, 0.15)
L = ipc.Dimension.from_nominal(2.1, 0.3)
T = ipc.Dimension(0.26, 0.46)
W = ipc.Dimension(0.15, 0.3)
if num_pins == 5:
# MO-203-C variant AA
return ipc.sot23_5(A, B, L, T, W, 0.65,
ipc.LandPatternSize.SOT(profile, A, L, T, 0.65))
elif num_pins == 6:
# MO-203-C variant AB
return ipc.in_line_pin_device(
A, B, L, B, T, W, 0.65, 3, 0,
ipc.LandPatternSize.SOT(profile, A, L, T, 0.65))
elif num_pins == 8:
# MO-203-C variant BA
W = ipc.Dimension(0.15, 0.27)
spec = ipc.LandPatternSize.SOT(profile, A, L, T, 0.5)
return ipc.in_line_pin_device(A, B, L, B, T, W, 0.5, 4, 0, spec)
else:
raise ValueError(
"No known standard dimensions for SOT23-{0}".format(num_pins))
def SC70(profile, num_pins):
"""Construct a land pattern for an SC70 device.
Supports 5, 6 and 8-pin devices, with dimensions from JEDEC
MO-203.
"""
A = ipc.Dimension.from_nominal(1.25, 0.15)
B = ipc.Dimension.from_nominal(2, 0.15)
L = ipc.Dimension.from_nominal(2.1, 0.3)
T = ipc.Dimension(0.26, 0.46)
W = ipc.Dimension(0.15, 0.3)
if num_pins == 5:
# MO-203-C variant AA
return ipc.sot23_5(
A, B, L, T, W, 0.65,
ipc.LandPatternSize.SOT(profile, A, L, T, 0.65))
elif num_pins == 6:
# MO-203-C variant AB
return ipc.in_line_pin_device(
A, B, L, B, T, W, 0.65, 3, 0,
ipc.LandPatternSize.SOT(profile, A, L, T, 0.65))
elif num_pins == 8:
# MO-203-C variant BA
W = ipc.Dimension(0.15, 0.27)
spec = ipc.LandPatternSize.SOT(profile, A, L, T, 0.5)
return ipc.in_line_pin_device(
A, B, L, B, T, W, 0.5, 4, 0, spec)
else:
raise ValueError("No known standard dimensions for SOT23-{0}".format(num_pins))
def SOT23(profile, num_pins):
"""Construct a land pattern for a SOT23 device.
Supports 3, 5, 6 and 8-pin devices, with dimensions from JEDEC
TO-236 and MO-178.
"""
if num_pins == 3:
# Dimensions from JEDEC TO-236-A[AB]
A = ipc.Dimension(1.2, 1.4)
B = ipc.Dimension(2.8, 3.04)
L = ipc.Dimension(2.1, 2.64)
T = ipc.Dimension(0.4, 0.6)
W = ipc.Dimension(0.3, 0.5)
return ipc.sot23_3(
A, B, L, T, W, 0.95,
ipc.LandPatternSize.SOT(profile, A, L, T, 0.95))
elif num_pins == 5:
# Dimensions from JEDEC MO-178-C variant AA
A = ipc.Dimension.from_nominal(1.6, 0.1)
B = ipc.Dimension.from_nominal(2.9, 0.1)
L = ipc.Dimension.from_nominal(2.8, 0.2)
T = ipc.Dimension(0.3, 0.6)
W = ipc.Dimension(0.3, 0.5)
return ipc.sot23_5(
A, B, L, T, W, 0.95,
ipc.LandPatternSize.SOT(profile, A, L, T, 0.95))
elif num_pins == 6:
# Dimensions from JEDEC MO-178-C variant AB
A = ipc.Dimension.from_nominal(1.6, 0.1)
B = ipc.Dimension.from_nominal(2.9, 0.1)
L = ipc.Dimension.from_nominal(2.8, 0.2)
T = ipc.Dimension(0.3, 0.6)
W = ipc.Dimension(0.3, 0.5)
return ipc.in_line_pin_device(
A, B, L, B, T, W, 0.95, 3, 0,
ipc.LandPatternSize.SOT(profile, A, L, T, 0.95))
elif num_pins == 8:
# Dimensions from JEDEC MO-178-C variant BA
A = ipc.Dimension.from_nominal(1.6, 0.1)
B = ipc.Dimension.from_nominal(2.9, 0.1)
L = ipc.Dimension.from_nominal(2.8, 0.2)
T = ipc.Dimension(0.3, 0.6)
W = ipc.Dimension(0.22, 0.38)
# SOT23-8 is almost at the threshold where IPC switches to
# much smaller side fillets. This causes overlap violations
# with the Most profile. As such, we force the narrower pitch
# profile here by using a smaller pitch.
spec = ipc.LandPatternSize.SOT(profile, A, L, T, 0.6)
return ipc.in_line_pin_device(
A, B, L, B, T, W, 0.65, 4, 0, spec)
else:
raise ValueError("No known standard dimensions for SOT23-{0}".format(num_pins))
def SOT23(profile, num_pins):
"""Construct a land pattern for a SOT23 device.
Supports 3, 5, 6 and 8-pin devices, with dimensions from JEDEC
TO-236 and MO-178.
"""
if num_pins == 3:
# Dimensions from JEDEC TO-236-A[AB]
A = ipc.Dimension(1.2, 1.4)
B = ipc.Dimension(2.8, 3.04)
L = ipc.Dimension(2.1, 2.64)
T = ipc.Dimension(0.4, 0.6)
W = ipc.Dimension(0.3, 0.5)
return ipc.sot23_3(
A, B, L, T, W, 0.95,
ipc.LandPatternSize.SOT(profile, A, L, T, 0.95))
elif num_pins == 5:
# Dimensions from JEDEC MO-178-C variant AA
A = ipc.Dimension.from_nominal(1.6, 0.1)
B = ipc.Dimension.from_nominal(2.9, 0.1)
L = ipc.Dimension.from_nominal(2.8, 0.2)
T = ipc.Dimension(0.3, 0.6)
W = ipc.Dimension(0.3, 0.5)
return ipc.sot23_5(
A, B, L, T, W, 0.95,
ipc.LandPatternSize.SOT(profile, A, L, T, 0.95))
elif num_pins == 6:
# Dimensions from JEDEC MO-178-C variant AB
A = ipc.Dimension.from_nominal(1.6, 0.1)
B = ipc.Dimension.from_nominal(2.9, 0.1)
L = ipc.Dimension.from_nominal(2.8, 0.2)
T = ipc.Dimension(0.3, 0.6)
W = ipc.Dimension(0.3, 0.5)
return ipc.in_line_pin_device(
A, B, L, B, T, W, 0.95, 3, 0,
ipc.LandPatternSize.SOT(profile, A, L, T, 0.95))
elif num_pins == 8:
# Dimensions from JEDEC MO-178-C variant BA
A = ipc.Dimension.from_nominal(1.6, 0.1)
B = ipc.Dimension.from_nominal(2.9, 0.1)
L = ipc.Dimension.from_nominal(2.8, 0.2)
T = ipc.Dimension(0.3, 0.6)
W = ipc.Dimension(0.22, 0.38)
# SOT23-8 is almost at the threshold where IPC switches to
# much smaller side fillets. This causes overlap violations
# with the Most profile. As such, we force the narrower pitch
# profile here by using a smaller pitch.
spec = ipc.LandPatternSize.SOT(profile, A, L, T, 0.6)
return ipc.in_line_pin_device(
A, B, L, B, T, W, 0.65, 4, 0, spec)
else:
raise ValueError("No known standard dimensions for SOT23-{0}".format(num_pins))
