G5Y-1 Datasheet, PDF (6/8 Pages) Omron Electronics LLC – Low Signal Relay

G5Y-1
Shape of land
1. The land section should be on the center line of the copper-
foil pattern so that the soldered fillets become uniform.
G5Y-1
The characteristic impedance of a transmission line is
determined by the type of PC board (specific inductive
capacity), its thickness, and the width of the transmission line.
This impedance is expressed by the following formula.
2. If the relay and other circuit components are to be soldered
manually after the automatic soldering of the PC board, a
terminal hole can be secured by providing a break in the
land.
Conductor width and microstrip
Patterns for DC circuits
The following thicknesses of copper foil are standard: 35 µm
(1.38 mil) and 70 µm (2.76 mil). The conductor width is
determined by the carry current and allowable temperature
rise. Refer to the table on the following page.
Conductor width and carry current
(according to IEC Pub321)
where
w: Width of transmission line
e_{r: Relative dielectric constant} e_r
h: Thickness of dielectric PC board, provided that the
thickness of copper foil is no greater than h.
This relationship is shown the the figure below.
s MICROSTRIPS
For high-frequency transmission circuits, the use of
microstrips is recommended. By adopting this stripline
method, a low-loss transmission circuit can be configured. The
microstrips are prepared by etching a PC board made of
dielectric material and covered on both sides with copper foil.
As shown in the figure below, the microstrip utilizes the
concentration of the electric field between transmission line
and the ground.
For example, when a 50Ω transmission line is to be formed
using a 1.6 mm (0.06) glass epoxy type double-sided PC
board, the width of the transmission line can be obtained in
the following manner. Since the specific inductive capacity (^er)
of this circuit board is 4.8, w/h = 1.7 (obtained from the above
table). Based on the thickness of the PC board (e.g., 1.6 mm
[0.06]), the thickness of transmission line w can be calculated
as follows.
w = h x 1.7 = 1.6 (0.06) x 1.7 =∼ 2.7 mm (0.11 in)
Note that in this calculation, the thickness of copper foil “t” is
ignored, so there may be a greater error in characteristic
impedance of t =∼ w. Also, the attenuation constant of the
transmission line, due to the effective filling rate of microstrip
or dielectric loss and conductor loss, is not taken into account,
but these factors must be considered in the actual design of
microstrips. In the frequency band for which Model G5Y is
intended, however, these factors may be ignored by
shortening the length of the transmission line.
Bending of strip transmission line
6