| US 7,603,645 B2 | ||
| Calibration method of insulating washer in circuit board | ||
| Yu-Li Su, Taipei (Taiwan); and Chun-Yu Lai, Taipei (Taiwan) | ||
| Assigned to Inventec Corporation, Taipei (Taiwan) | ||
| Filed on Jan. 29, 2007, as Appl. No. 11/698,885. | ||
| Prior Publication US 2008/0184175 A1, Jul. 31, 2008 | ||
| Int. Cl. G06F 17/50 (2006.01); H03K 17/693 (2006.01); H05K 1/11 (2006.01); H05K 7/12 (2006.01) | ||
| U.S. Cl. 716—15 [716/1; 716/2; 174/261; 174/265; 174/138 G] | 6 Claims |
| 1. A calibration method of insulating washer in a circuit board, wherein an insulating washer is disposed around a metal via,
the calibration method comprising the steps of:
(a) establishing an equivalent circuit model corresponding to the metal via, and storing the same in a computer;
(b) with computer software run on the computer;
(i) depicting an electric characteristic curve corresponding to the equivalent circuit model;
(ii) calculating a capacitance equation and an inductance equation corresponding to the electric characteristic curve;
(iii) substituting parameter values of the equivalent circuit model, the capacitance equation, and the inductance equation
into a characteristic impedance expression for being calculated, so as to obtain a first radius length value of the insulating
washer for the metal via;
(iv) making a temporary insulating washer by employing the first radius length value;
(v) reestablishing an equivalent circuit model corresponding to the metal via according to the temporary insulating washer;
(c) repeating steps (i), (ii), (iii), (iv), and (v) until the first radius length value is converged to be a fixed value;
and
(d) when the first radius length value is converged to the fixed value in step (c), determining the fixed value as an optimum
value for designing the insulating washer.
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