Adcom - PCB Layout - Embedded

      Embedded Resistors

             • The resistance substrates comes in different types of value sheets
             • Main manufactures are : Ohmega, Rohm, Shipely

Sheet Resistivity	Ohmega-Ply® Film Average Thickness	Material Tolerance
10Ω/ϒ	1.00 Micron	3%
25Ω/ϒ	0.40 Micron	5%
50Ω/ϒ	0.20 Micron	5%
100Ω/ϒ	0.10 Micron	5%
250Ω/ϒ	0.05 Micron	10%

      Resistor Types

             • Bar Type
                       • Multiple Squares (N≥1)                                                                                                 • Partial Squares (N<1)

             • Meander Type
                       • Basically, a meander resisitor can be considered as a bar resistor
                         with the exception of the corner squares (right-angle bends).
                         Due to the change in current density at right angle path,
                         the effective number of square is 0.56.

                                                                                                                                                       e.g., sheet resistance (Rs) = 100Ω/ϒ
                                                                                                                                                                           No. of squares = 37
                                                                                                                                                               No. of corner squares = 16
                                                                                                                                                  Total No. of effective squares = 37+(16 x 0.56)
                                                                                                                                                                                                        = 45.9
                                                                                                                                                                                                        ≈ 46
                                                                                                                                                                       Resistance value = 46 x 100
                                                                                                                                                                                                        = 4.6KΩ