PCB
Quotation | PCB
Services | PCB
Layout Quote | Free
Software | Books | Design
Guidelines | PCB
Glossary
Industry Yellow Pages | Semi
Conductor Companies
| PCB Thickness |
PCB Material | Submit
Company
PCB Design Article | Customers Comments |
Contact Us | Home
PCB Design Guidelines
Below are
a number of Guideline Rules to follow and keep in mind when designing PCBs.
These are general rules that apply for the most PCB fabricators, but it is advisable
to check with your fabricator.
Board Size
PCB manufacturers
have a maximum size board they can handle. Typically this is also their panel
size. The PCB fabrication house's panel size is also important when mass producing boards.
In this situation one would want to fit as many boards as possible on a panel
with as little wasted board space as possible (in order to reduce costs). Normal
board spacing for routing (how boards are separated on a panel) is 0.3", plus
there is typically a 1.0" to 2.0" border on the board for handling it during
processing.
Board thickness
may also be specified. A standard thickness and type of board is .062" FR4.
Other typical board thickness are .010", .020", .031", and .092".
Trace Width and Spacing
The chemical
and photographic processes used to produce a PCB put requirements on the minimum
width of trace and the minimum spacing between traces. If a trace is made smaller
than this minimum width there is some chance it will open (no connection) when
manufactured. If two traces are closer together than the minimum spacing there
is some chance they will short when manufactured. These parameters are usually
specified as "x/y rules", where x is the minimum trace width and y is the minimum
trace spacing. For example, "8/10 rules" would indicate 8 mil minimum trace
width and 10 mil minimum trace spacing. These rules (especially spacing) apply
to any metal on the PCB, including pad to track spacing and line widths for
strings on the PCB.
Typical
modern process rules are 8/8 rules with values as small as 2/2 rules being available.
For Press-n-Peel people have had success using 12/12 rules, but values a little
larger are easier to make work consistently. However, keep in mind that the
board must be soldered and a trace within 8 mils (8/8 rules) of a pad is easier
to short than one with greater spacing when hand soldered. For hand soldering
10/10 rules are much easier to solder (if the design density can allow spacing
this large).
Pad Sizes
The biggest
issues with pad size are solder ability and manufacturability. Solder ability is really just a matter of skill and will not be discussed here. Manufacturability
is concerned with whether or not the pad will be broken when the hold is drilled
in it. This is mainly a function of the accuracy of the PCB manufacturer's drilling.
If a drill hole is slightly off center the pad may be broken at one edge possibly
leading to an open in the circuit. A standard requirement for pad sizes is a
5 mil annulus. This means there must be .005" all around the hole (i.e. a 28
mil hole would require a 38 mil pad). Something a little larger than this (maybe
10 mils) is recommended for solder ability. AP Circuits states they have had
relatively consistent success with a 2.5 mil annulus (i.e. a 20 mil hole with
only a 25 mil pad), but they don't recommend it.
Hole Sizes
Most PCB
manufacturers have a wide selection of drill (hole) sizes available. Some charge
per drill size used, others offer a standard set of drill sizes for no charge
and then charge for any non-standard drill sizes. AP Circuits uses the latter
approach. When choosing a hole size remember that the plate-through will cause
the hole to effectively be more narrow. The plate-through thickness varies from
.001" to .003". AP Circuits' plate-through thickness is approximately .015"
(meaning the "finished hole" diameter is 3 mils smaller).
Standard Drill Sizes
Drill
Number
|
Hole
Size
|
Finished
Hole Size
|
70
|
.028"
|
.025"
|
65
|
.035"
|
.032"
|
58
|
.042"
|
.039"
|
55
|
.052"
|
.049"
|
53
|
.0595"
|
.056"
|
44
|
.086"
|
.083"
|
1/8"
|
.125"
|
.122"
|
24
|
.152"
|
.149"
|
Hole
Density
Hole density
is purely a cost issue. The more holes there are on a board the more wear and
tear manufacturing will put on the equipment (and thus the more the board will
cost). Most PCB manufacturers have a maximum hole density and boards with greater
density are charged more. For AP Circuits, there is a per hole charge for densities
above 24 holes per square inch.
Drill Chart
Drill
No.
|
Inches
|
|
Drill
No.
|
Inches
|
|
Drill
No.
|
Inches
|
80
|
.0135
|
|
53
|
.0595
|
|
27
|
.1440
|
79
|
.0145
|
|
52
|
.0635
|
|
26
|
.1470
|
78
|
.0160
|
|
51
|
.0670
|
|
25
|
.1495
|
77
|
.0180
|
|
50
|
.0700
|
|
24
|
.1520
|
76
|
0200
|
|
49
|
.0730
|
|
23
|
.1540
|
75
|
.0210
|
|
48
|
.0760
|
|
22
|
.1570
|
74
|
.0225
|
|
47
|
.0785
|
|
21
|
.1590
|
73
|
.0240
|
|
46
|
.0810
|
|
20
|
.1610
|
72
|
.0250
|
|
45
|
.0820
|
|
19
|
.1660
|
71
|
.0260
|
|
44
|
.0860
|
|
18
|
.1695
|
70
|
.0280
|
|
43
|
.0890
|
|
17
|
.1730
|
69
|
.0292
|
|
42
|
.0935
|
|
16
|
.1770
|
68
|
.0310
|
|
41
|
.0960
|
|
15
|
.1800
|
67
|
.0320
|
|
40
|
.0980
|
|
14
|
.1820
|
66
|
.0330
|
|
39
|
.0995
|
|
13
|
.1850
|
65
|
.0350
|
|
38
|
.1015
|
|
12
|
.1890
|
64
|
.0360
|
|
37
|
.1040
|
|
11
|
.1910
|
63
|
.0370
|
|
36
|
.1065
|
|
10
|
.1935
|
62
|
.0380
|
|
35
|
.1100
|
|
09
|
.1960
|
61
|
.0390
|
|
34
|
.1110
|
|
08
|
.1990
|
60
|
.0400
|
|
33
|
.1130
|
|
07
|
.2010
|
59
|
.0410
|
|
32
|
.1160
|
|
06
|
.2040
|
58
|
.0420
|
|
31
|
.1200
|
|
05
|
.2055
|
57
|
.0430
|
|
1/8"
|
.1250
|
|
04
|
.2090
|
56
|
.0465
|
|
30
|
.1285
|
|
03
|
.2130
|
55
|
.0520
|
|
29
|
.1360
|
|
02
|
.2210
|
54
|
.0550
|
|
28
|
.1405
|
|
01
|
.2280
|
dBm - Volts - Watts Conversion
dBm
|
V
|
Po
|
|
dBm
|
V
|
Po
|
|
dBm
|
uV
|
Po
|
+53
|
100.0
|
200W
|
|
+7
|
0.50
|
5mW
|
|
-37
|
3.2
|
|
+50
|
70.0
|
100W
|
|
+6
|
0.445
|
4mW
|
|
-38
|
2.85
|
|
+49
|
64.0
|
80W
|
|
+5
|
0.40
|
3.2mW
|
|
-39
|
2.5
|
|
+48
|
58.0
|
64W
|
|
+4
|
0.355
|
2.5mW
|
|
-40
|
2.25
|
0.1uW
|
+47
|
50.0
|
50W
|
|
+3
|
0.320
|
2.0mW
|
|
-41
|
2.0
|
|
+46
|
44.5
|
40W
|
|
+2
|
0.280
|
1.6mW
|
|
-42
|
1.8
|
|
+45
|
40.0
|
32W
|
|
+1
|
0.252
|
1.25mW
|
|
-43
|
1.6
|
|
+44
|
32.5
|
25W
|
|
0
|
0.225
|
1.00mW
|
|
-44
|
1.4
|
|
+43
|
32.0
|
20W
|
|
-1
|
0.200
|
0.80mW
|
|
-45
|
1.25
|
|
+42
|
28.0
|
16W
|
|
-2
|
0.180
|
0.64mW
|
|
-46
|
1.18
|
|
+41
|
26.2
|
12.5W
|
|
-3
|
0.160
|
0.50mW
|
|
-47
|
1.00
|
|
+40
|
22.5
|
10W
|
|
-4
|
0.141
|
0.40mW
|
|
-48
|
0.90
|
|
+39
|
20.0
|
8W
|
|
-5
|
0.125
|
0.32mW
|
|
-49
|
800
|
|
+38
|
18.0
|
6.4W
|
|
-6
|
0.115
|
0.25mW
|
|
-50
|
710
|
0.01uW
|
+37
|
16.0
|
5W
|
|
-7
|
0.100
|
0.20mW
|
|
-51
|
640
|
|
+36
|
14.1
|
4W
|
|
-8
|
0.090
|
0.16mW
|
|
-52
|
570
|
|
+35
|
12.5
|
3.2W
|
|
-9
|
0.080
|
0.125mW
|
|
-53
|
500
|
|
+34
|
11.5
|
2.5W
|
|
-10
|
0.071
|
0.10mW
|
|
-54
|
450
|
|
+33
|
10.0
|
2W
|
|
-11
|
64
|
|
|
-55
|
0.40
|
|
+32
|
9.0
|
1.6W
|
|
-12
|
58
|
|
|
-56
|
351
|
|
+31
|
8.0
|
1.25W
|
|
-13
|
50
|
|
|
-57
|
320
|
|
+30
|
7.10
|
1.0W
|
|
-14
|
45
|
|
|
-58
|
286
|
|
+29
|
6.40
|
800mW
|
|
-15
|
40
|
|
|
-59
|
251
|
|
+28
|
5.80
|
640mW
|
|
-16
|
35.5
|
|
|
-60
|
225
|
0.001uW
|
+27
|
5.00
|
500mW
|
|
-17
|
31.5
|
|
|
-61
|
200
|
|
+26
|
4.45
|
400mW
|
|
-18
|
28.5
|
|
|
-62
|
180
|
|
+25
|
4.00
|
320mW
|
|
-19
|
25.1
|
|
|
-63
|
160
|
|
+24
|
3.55
|
250mW
|
|
-20
|
22.5
|
0.01mW
|
|
-64
|
141
|
|
+23
|
3.20
|
200mW
|
|
-21
|
20.0
|
|
|
-65
|
128
|
|
+22
|
2.80
|
160mW
|
|
-22
|
17.9
|
|
|
-66
|
115
|
|
+21
|
2.52
|
125mW
|
|
-23
|
15.9
|
|
|
-67
|
100
|
|
+20
|
2.25
|
100mW
|
|
-24
|
14.1
|
|
|
-68
|
90
|
|
+19
|
2.00
|
80mW
|
|
-25
|
12.8
|
|
|
-69
|
80
|
|
+18
|
1.80
|
64mW
|
|
-26
|
11.5
|
|
|
-70
|
71
|
0.1nW
|
+17
|
1.60
|
50mW
|
|
-27
|
10.0
|
|
|
-71
|
65
|
|
+16
|
1.41
|
40mW
|
|
-28
|
8.9
|
|
|
-72
|
58
|
|
+15
|
1.25
|
32mW
|
|
-29
|
8.0
|
|
|
-73
|
50
|
|
+14
|
1.15
|
25mW
|
|
-30
|
7.1
|
0.001mW
|
|
-74
|
45
|
|
+13
|
1.00
|
20mW
|
|
-31
|
6.25
|
|
|
-75
|
40
|
|
+12
|
0.90
|
16mW
|
|
-32
|
5.8
|
|
|
-76
|
35
|
|
+11
|
0.80
|
12.5mW
|
|
-33
|
5.0
|
|
|
-77
|
32
|
|
+10
|
0.71
|
10mW
|
|
-34
|
4.5
|
|
|
-78
|
29
|
|
+9
|
0.64
|
8mW
|
|
-35
|
4.0
|
|
|
-79
|
25
|
|
+8
|
0.58
|
6.4mW
|
|
-36
|
3.5
|
|
|
-80
|
22.5
|
0.01nW
|
Getek® Laminates
- Epoxy / Polyphenylene Oxide Resin
(Type: NEMA FR-4,
IPC-L-108B/04)
Nominal
thickness
|
Thickness
tolerance
|
GE grade
|
E-Glass
construction
|
Dk@1MHz.
|
0.0027"
|
�0.0005"
|
ML200D
|
1080
|
3.8
|
0.004"
|
�0.0005"
|
ML200D
|
2313
|
3.9
|
0.005"
|
�0.0007"
|
ML200M
|
2313/106
|
3.8
|
0.006"
|
�0.0007"
|
ML200D
|
2313/1080
|
3.9
|
0.007"
|
�0.0010"
|
ML200M
|
(2)2313
|
3.8
|
0.008"
|
�0.0010"
|
ML200D
|
2313/2116
|
3.9
|
0.010"
|
�0.0010"
|
ML200D
|
(2)2116
|
3.9
|
0.012"
|
�0.0010"
|
ML200D
|
1080/7628/1080
|
3.9
|
0.014"
|
�0.0015"
|
ML200D
|
(2)7628
|
4.2
|
0.018"
|
�0.0015"
|
ML200D
|
7628/2313/7628
|
4.1
|
0.021"
|
�0.0020"
|
ML200D
|
(3)7628
|
4.2
|
0.024"
|
�0.0020"
|
ML200C
|
2116/(2)7628/2116
|
4.1
|
0.028"
|
�0.0020"
|
ML200D
|
(4)7628
|
4.2
|
0.028"(Alt.)
|
�0.0020"
|
ML200C
|
1080/2313/(3)2116/2313/1080
|
3.8
|
0.031"
|
�0.0030"
|
ML200C
|
2116/(3)7628/2116
|
4.1
|
0.031"1
|
�0.0040"
|
ML200D
|
(4)7628
|
4.2
|
0.044"1
|
�0.0050"
|
ML200D
|
(6)7628
|
4.2
|
0.059"1
|
�0.0050"
|
ML200D
|
(8)7628
|
4.2
|
VSWR Vs. Return Loss
VSWR
|
Ret.
Loss
|
VSWR
|
Ret.
Loss
|
VSWR
|
Ret.
Loss
|
VSWR
|
Ret.
Loss
|
VSWR
|
Ret.
Loss
|
1.01
|
-46.064
|
1.51
|
-13.842
|
1.79
|
-10.960
|
2.18
|
-8.611
|
2.57
|
-7.135
|
1.02
|
-40.086
|
1.52
|
-13.708
|
1.80
|
-10.881
|
2.19
|
-8.565
|
2.58
|
-7.105
|
1.03
|
-36.608
|
1.53
|
-13.577
|
1.81
|
-10.804
|
2.20
|
-8.519
|
2.59
|
-7.074
|
1.04
|
-34.151
|
1.54
|
-13.449
|
1.82
|
-10.729
|
2.21
|
-8.474
|
2.60
|
-7.044
|
1.05
|
-32.256
|
1.55
|
-13.324
|
1.83
|
-10.654
|
2.22
|
-8.430
|
2.61
|
-7.014
|
1.06
|
-30.714
|
1.56
|
-13.201
|
1.84
|
-10.581
|
2.23
|
-8.386
|
2.62
|
-6.984
|
1.07
|
-29.417
|
1.57
|
-13.081
|
1.85
|
-10.509
|
2.24
|
-8.342
|
2.63
|
-6.954
|
1.08
|
-28.299
|
1.58
|
-12.964
|
1.86
|
-10.437
|
2.25
|
-8.299
|
2.64
|
-6.925
|
1.09
|
-27.318
|
1.59
|
-12.849
|
1.87
|
-10.367
|
2.26
|
-8.257
|
2.65
|
-6.896
|
1.10
|
-26.444
|
1.60
|
-12.736
|
1.88
|
-10.298
|
2.27
|
-8.215
|
2.66
|
-6.867
|
1.11
|
-25.658
|
1.61
|
-12.626
|
1.89
|
-10.230
|
2.28
|
-8.173
|
2.67
|
-6.839
|
1.12
|
-24.943
|
1.62
|
-12.518
|
1.90
|
-10.163
|
2.29
|
-8.132
|
2.68
|
-6.811
|
1.13
|
-24.289
|
1.63
|
-12.412
|
1.91
|
-10.097
|
2.30
|
-8.091
|
2.69
|
-6.783
|
1.14
|
-23.686
|
1.64
|
-12.308
|
1.92
|
-10.032
|
2.31
|
-8.051
|
2.70
|
-6.755
|
1.15
|
-23.127
|
1.65
|
-12.207
|
1.93
|
-9.968
|
2.32
|
-8.011
|
2.71
|
-6.728
|
1.16
|
-22.607
|
1.66
|
-12.107
|
1.94
|
-9.904
|
2.33
|
-7.972
|
2.72
|
-6.700
|
1.17
|
-22.120
|
1.67
|
-12.009
|
1.95
|
-9.842
|
2.34
|
-7.933
|
2.73
|
-6.673
|
1.18
|
-21.664
|
1.68
|
-11.913
|
1.96
|
-9.780
|
2.35
|
-7.894
|
2.74
|
-6.646
|
1.19
|
-21.234
|
1.69
|
-11.818
|
1.97
|
-9.720
|
2.36
|
-7.856
|
2.75
|
-6.620
|
1.20
|
-20.828
|
1.70
|
-11.725
|
1.98
|
-9.660
|
2.37
|
-7.818
|
2.76
|
-6.594
|
1.21
|
-20.443
|
1.71
|
-11.634
|
1.99
|
-9.601
|
2.38
|
-7.781
|
2.77
|
-6.567
|
1.22
|
-20.079
|
1.72
|
-11.545
|
2.00
|
-9.542
|
2.39
|
-7.744
|
2.78
|
-6.541
|
1.23
|
-19.732
|
1.73
|
-11.457
|
2.01
|
-9.485
|
2.40
|
-7.707
|
2.79
|
-6.516
|
1.24
|
-19.401
|
1.74
|
-11.370
|
2.02
|
-9.428
|
2.41
|
-7.671
|
2.80
|
-6.490
|
1.25
|
-19.085
|
1.75
|
-11.285
|
2.03
|
-9.372
|
2.42
|
-7.635
|
2.81
|
-6.465
|
1.26
|
-18.783
|
1.76
|
-11.202
|
2.04
|
-9.317
|
2.43
|
-7.599
|
2.82
|
-6.440
|
1.27
|
-18.493
|
1.77
|
-11.120
|
2.05
|
-9.262
|
2.44
|
-7.564
|
2.83
|
-6.415
|
1.28
|
-18.216
|
1.78
|
-11.039
|
2.06
|
-9.208
|
2.45
|
-7.529
|
2.84
|
-6.390
|
1.29
|
-17.949
|
1.40
|
-15.563
|
2.07
|
-9.155
|
2.46
|
-7.494
|
2.85
|
-6.366
|
1.30
|
-17.692
|
1.41
|
-15.385
|
2.08
|
-9.103
|
2.47
|
-7.460
|
2.86
|
-6.341
|
1.31
|
-17.445
|
1.42
|
-15.211
|
2.09
|
-9.051
|
2.48
|
-7.426
|
2.87
|
-6.317
|
1.32
|
-17.207
|
1.43
|
-15.043
|
2.10
|
-8.999
|
2.49
|
-7.393
|
2.88
|
-6.293
|
1.33
|
-16.977
|
1.44
|
-14.879
|
2.11
|
-8.949
|
2.50
|
-7.360
|
2.89
|
-6.270
|
1.34
|
-16.755
|
1.45
|
-14.719
|
2.12
|
-8.899
|
2.51
|
-7.327
|
2.90
|
-6.246
|
1.35
|
-16.540
|
1.46
|
-14.564
|
2.13
|
-8.849
|
2.52
|
-7.294
|
2.91
|
-6.223
|
1.36
|
-16.332
|
1.47
|
-14.412
|
2.14
|
-8.800
|
2.53
|
-7.262
|
2.92
|
-6.200
|
1.37
|
-16.131
|
1.48
|
-14.264
|
2.15
|
-8.752
|
2.54
|
-7.230
|
2.93
|
-6.177
|
1.38
|
-15.936
|
1.49
|
-14.120
|
2.16
|
-8.705
|
2.55
|
-7.198
|
2.94
|
-6.154
|
1.39
|
-15.747
|
1.50
|
-13.979
|
2.17
|
-8.657
|
2.56
|
-7.167
|
2.95
|
-6.131
|
VSWR Vs. Return Loss (Continued)
VSWR
|
Ret.
Loss
|
VSWR
|
Ret.
Loss
|
VSWR
|
Ret.
Loss
|
VSWR
|
Ret.
Loss
|
VSWR
|
Ret.
Loss
|
2.96
|
-6.109
|
3.07
|
-5.872
|
3.18
|
-5.654
|
3.29
|
-5.452
|
3.40
|
-5.265
|
2.97
|
-6.086
|
3.08
|
-5.852
|
3.19
|
-5.635
|
3.30
|
-5.435
|
3.41
|
-5.248
|
2.98
|
-6.064
|
3.09
|
-5.832
|
3.20
|
-5.617
|
3.31
|
-5.417
|
3.42
|
-5.232
|
2.99
|
-6.042
|
3.10
|
-5.811
|
3.21
|
-5.598
|
3.32
|
-5.400
|
3.43
|
-5.216
|
3.00
|
-6.021
|
3.11
|
-5.791
|
3.22
|
-5.579
|
3.33
|
-5.383
|
3.44
|
-5.200
|
3.01
|
-5.999
|
3.12
|
-5.771
|
3.23
|
-5.561
|
3.34
|
-5.365
|
3.45
|
-5.184
|
3.02
|
-5.977
|
3.13
|
-5.751
|
3.24
|
-5.542
|
3.35
|
-5.348
|
3.46
|
-5.168
|
3.03
|
-5.956
|
3.14
|
-5.732
|
3.25
|
-5.524
|
3.36
|
-5.331
|
3.47
|
-5.152
|
3.04
|
-5.935
|
3.15
|
-5.712
|
3.26
|
-5.506
|
3.37
|
-5.315
|
3.48
|
-5.137
|
3.05
|
-5.914
|
3.16
|
-5.693
|
3.27
|
-5.488
|
3.38
|
-5.298
|
3.49
|
-5.121
|
3.06
|
-5.893
|
3.17
|
-5.674
|
3.28
|
-5.470
|
3.39
|
-5.281
|
3.50
|
-5.105
|
WIRE DATA CHART
AWG
|
Diam
(In.)
|
|
AWG
|
Diam
(In.)
|
|
AWG
|
Diam
(In.)
|
|
AWG
|
Diam
(In.)
|
4/0
|
0.4600
|
|
9
|
0.1144
|
|
21
|
0.0285
|
|
33
|
0.0071
|
3/0
|
0.4096
|
|
10
|
0.1019
|
|
22
|
0.0253
|
|
34
|
0.0063
|
2/0
|
0.3648
|
|
11
|
0.0907
|
|
23
|
0.0226
|
|
35
|
0.0056
|
1/0
|
0.3249
|
|
12
|
0.0808
|
|
24
|
0.0201
|
|
36
|
0.0050
|
1
|
0.2893
|
|
13
|
0.0720
|
|
25
|
0.0179
|
|
37
|
0.0045
|
2
|
0.2576
|
|
14
|
0.0641
|
|
26
|
0.0159
|
|
38
|
0.0040
|
3
|
0.2294
|
|
15
|
0.0571
|
|
27
|
0.0142
|
|
39
|
0.0035
|
4
|
0.2043
|
|
16
|
0.0508
|
|
28
|
0.0126
|
|
40
|
0.0031
|
5
|
0.1819
|
|
17
|
0.0453
|
|
29
|
0.0113
|
|
41
|
0.0028
|
6
|
0.1620
|
|
18
|
0.0403
|
|
30
|
0.0100
|
|
42
|
0.0025
|
7
|
0.1443
|
|
19
|
0.0359
|
|
31
|
0.0089
|
|
43
|
0.0022
|
8
|
0.1285
|
|
20
|
0.0320
|
|
32
|
0.0080
|
|
44
|
0.0020
|
PCMCIA CONNECTOR PIN OUT
16-Bit
Pin
|
32-bit
Memory
|
16-Bit
I/O+Mem
|
32-bit
CardBus
|
Pin
|
Memory
|
I/O+Mem
|
CardBus
|
1
|
GND
|
GND
|
GND
|
35
|
GND
|
GND
|
GND
|
2
|
D3
|
D3
|
CAD0
|
36
|
CD1#
|
CD1#
|
CCD1#
|
3
|
D4
|
D4
|
CAD1
|
37
|
D11
|
D11
|
CAD2
|
4
|
D5
|
D5
|
CAD3
|
38
|
D12
|
D12
|
CAD4
|
5
|
D6
|
D6
|
CAD5
|
39
|
D13
|
D13
|
CAD6
|
6
|
D7
|
D7
|
CAD7
|
40
|
D14
|
D14
|
RSRVD
|
7
|
CE1#
|
CE1#
|
CCBE0#
|
41
|
D15
|
D15
|
CAD8
|
8
|
A10
|
A10
|
CAD9
|
42
|
CE2#
|
CE2#
|
CAD10
|
9
|
OE#
|
OE#
|
CAD11
|
43
|
VS1#
|
VS1#
|
CVS1
|
10
|
A11
|
A11
|
CAD12
|
44
|
RSRVD
|
IORD#
|
CAD13
|
11
|
A9
|
A9
|
CAD14
|
45
|
RSRVD
|
IOWR#
|
CAD15
|
12
|
A8
|
A8
|
CCBE1#
|
46
|
A17
|
A17
|
CAD16
|
13
|
A13
|
A13
|
CPAR
|
47
|
A18
|
A18
|
RSRVD
|
14
|
A14
|
A14
|
CPERR#
|
48
|
A19
|
A19
|
CBLOCK#
|
15
|
WE#
|
WE#
|
CGNT#
|
49
|
A20
|
A20
|
CSTOP#
|
16
|
READY
|
IREQ#
|
CINT#
|
50
|
A21
|
A21
|
CDEVSEL#
|
17
|
Vcc
|
Vcc
|
Vcc
|
51
|
Vcc
|
Vcc
|
Vcc
|
18
|
Vpp1
|
Vpp1
|
Vpp1
|
52
|
Vpp2
|
Vpp2
|
Vpp2
|
19
|
A16
|
A16
|
CCLK
|
53
|
A22
|
A22
|
CTRDY#
|
20
|
A15
|
A15
|
CIRDY#
|
54
|
A23
|
A23
|
CFRAME#
|
21
|
A12
|
A12
|
CCBE2#
|
55
|
A24
|
A24
|
CAD17
|
22
|
A7
|
A7
|
CAD18
|
56
|
A25
|
A25
|
CAD19
|
23
|
A6
|
A6
|
CAD20
|
57
|
VS2#
|
VS2#
|
CVS2
|
24
|
A5
|
A5
|
CAD21
|
58
|
RESET
|
RESET
|
CRST#
|
25
|
A4
|
A4
|
CAD22
|
59
|
WAIT#
|
WAIT#
|
CSERR#
|
26
|
A3
|
A3
|
CAD23
|
60
|
RSRVD
|
INPACK#
|
CREQ#
|
27
|
A2
|
A2
|
CAD24
|
61
|
REG#
|
REG#
|
CCBE3#
|
28
|
A1
|
A1
|
CAD25
|
62
|
BVD2
|
SPKR#
|
CAUDIO
|
29
|
A0
|
A0
|
CAD26
|
63
|
BVD1
|
STSCHG#
|
CSTSCHG
|
30
|
D0
|
D0
|
CAD27
|
64
|
D8
|
D8
|
CAD28
|
31
|
D1
|
D1
|
CAD29
|
65
|
D9
|
D9
|
CAD30
|
32
|
D2
|
D2
|
RSRVD
|
66
|
D10
|
D10
|
CAD31
|
33
|
WP
|
IOIS16#
|
CCLKRUN#
|
67
|
CD2#
|
CD2#
|
CCD2#
|
34
|
GND
|
GND
|
GND
|
68
|
GND
|
GND
|
GND
|
TRACE SPACING GUIDELINE
Voltage
Between Conductors
VDC or
Peak
|
A1
|
A2
|
A3
|
A4
|
A5
|
A6
|
A7
|
0 thru
15 0
|
.004
|
0.025
|
0.025
|
0.005
|
0.005
|
0.005
|
0.005
|
16 thru
30 0
|
.004 0
|
.025
|
0.025
|
0.005
|
0.005
|
0.010
|
0.005
|
31 thru
50 0
|
.004
|
0.025
|
0.025
|
0.005
|
0.005
|
0.015
|
0.005
|
51 thru 100
|
0.004
|
0.025
|
0.060
|
0.005
|
0.005
|
0.020
|
0.005
|
101 thru 150
|
0.008
|
0.025
|
0.125
|
0.015
|
0.015
|
0.030
|
0.015
|
151 thru 170
|
0.008
|
0.050
|
0.125
|
0.015
|
0.015
|
0.030
|
0.015
|
171 thru 250
|
0.008
|
0.050
|
0.250
|
0.015
|
0.015
|
0.030
|
0.015
|
251 thru 300
|
0.008
|
0.050
|
0.500
|
0.015
|
0.015
|
0.030
|
0.015
|
301 thru 500
|
0.010
|
0.100
|
0.500
|
0.030
|
0.030
|
0.060
|
0.030
|
More than 500
|
0.0001/V
|
0.0002/V 0.001/V
|
0.00012/V
|
0.00012/V
|
|
0.00012/V
|
0.00012/V
|
A1 - Internal
Conductors
A2 - External Conductors, uncoated, sea level to 10,000 ft.
A3 - External Conductors, uncoated, over 10,000 ft.
A4 - External Conductors, with permanent polymer coating (Solder
Mask).
A5 - External Conductors, with conformal coating over assembly.
A6 - External Component lead/termination, uncoated.
A7 - External Component lead/termination, with conformal coating.
Electrical Design Factors
Conductor Capacitance
C = 0.31 a/b
+ 0.23(1 + k) log10 (1 + 2b/d +2b + b2/d2)
Where
k = Substrate
dielectric constant
a = Conductor thickness
b = Width of conductor
in inches
d = Distance between
conductors in inches
Conductor Resistance
R = 0.000227W
Where
W = Width
of conductor
Characteristic Impedance
Zo = R + jwL
/ G + kwC
Where
Zo = Apparent
Z of an infinitely long line in ohms
R = Resistance in ohms
L = Inductance in Henries
G = Conductor per unit
length of line in mhos
C = Capacitance in farads
Characteristic Impedance for a
Micro Strip
Zo = (h/W)
(377 / (Sqrt. er) {1 + (2h/PI W)[1 + ln(PI W/h)]}
Where
h = Dielectric
thickness
W = Micro Strip width
er = Effective
dielectric constant of substrate
1-800-319-3599
E-Mail: info@pcbdesignandfab.com
|