Impedance Controlled PCB Differential Impedance Circuit Board 8
Layer PCB for Wireless HDMI
1.1 General description
This is a type of 8 layer printed circuit board built on FR-4
substrate with Tg 170°C for the application of Wireless HDMI. It's
1.6 mm thick with white silkscreen(Taiyo) on green solder mask
(Taiyo) and immersion gold on pads. It's also an impedance
controlled PCB with single-end impedance and differential impedance
controlled on on top layer and bottom layer. The base material is
from Taiwan ITEQ supplying 1 up PCB per panel. They're fabricated
per IPC 6012 Class 2 using supplied Gerber data. Each 25 panels are
packed for shipment.
1.2 Features and benifits
Lead free assemblies with a maximum reflow temperature of 260℃
High solderability, no stressing of circuit boards and less
contamination of PCB surface.
AOI inspection
8000 types of PCB per month
12 hours quotation
Free-of-charge PCB panelization
1.3 Applications
USB Adapter
WiFi USB Dongle
GPRS Modem
1.4 Parameter and data sheet
| PCB SIZE | 109.3 x 107.41mm=1PCS |
| BOARD TYPE | Multilayer PCB |
| Number of Layers | 8 layers |
| Surface Mount Components | YES |
| Through Hole Components | YES |
| LAYER STACKUP | copper ------- 18um(0.5oz)+plate TOP layer |
| Prepreg 7628(43%) 0.195mm |
| copper ------- 35um(1oz) MidLayer 1 |
| FR-4 0.2mm |
| copper ------- 35um(1oz) MidLayer 2 |
| Prepreg 7628(43%) 0.195mm |
| copper ------- 35um(1oz) MidLayer 3 |
| FR-4 0.2mm |
| copper ------- 35um(1oz) MidLayer 4 |
| Prepreg 7628(43%) 0.195mm |
| copper ------- 35um(1oz) MidLayer 5 |
| FR-4 0.2mm |
| copper ------- 35um(1oz) MidLayer 6 |
| Prepreg 7628(43%) 0.195mm |
| copper ------- 18um(0.5oz)+plate BOT Layer |
| TECHNOLOGY | |
| Minimum Trace and Space: | 4mil/4mil |
| Minimum / Maximum Holes: | 0.3/6.19mm |
| Number of Different Holes: | 24 |
| Number of Drill Holes: | 5158 |
| Number of Milled Slots: | 0 |
| Number of Internal Cutouts: | 0 |
| Impedance Control: | Single-Ended Trace Width:L1, L3, L6, L8 4mils --- 50 ohm,
Differential trace/space: top layer 5.1/6.0 mils -- 90 ohm, 5.1 / 8
mils --- 100 ohm, L6 5.1 / 8 mils --- 100 ohm; bottom layer 5.1 mil
/6 mils --- 90 ohm, 5.1mils / 8 mils --- 100 ohm |
| Number of Gold finger: | 0 |
| BOARD MATERIAL | |
| Glass Epoxy: | FR-4 TG170℃, er<5.4.IT-180, ITEQ Supplied |
| Final foil external: | 1oz |
| Final foil internal: | 1oz |
| Final height of PCB: | 1.6mm ±0.16 |
| PLATING AND COATING | |
| Surface Finish | Immersion gold (26.1% ) 0.05µm over 3µm nickel |
| Solder Mask Apply To: | TOP and Bottom, 12micron Minimum |
| Solder Mask Color: | Green, PSR-2000GT600D, Taiyo Supplied. |
| Solder Mask Type: | LPSM |
| CONTOUR/CUTTING | Routing, stamp holes. |
| MARKING | |
| Side of Component Legend | TOP and Bottom. |
| Colour of Component Legend | White, IJR-4000 MW300, Taiyo Supplied. |
| Manufacturer Name or Logo: | Marked on the board in a conductor and leged FREE AREA |
| VIA | Plated through hole(PTH), Via in pad, Resin via plug, via capped. |
| FLAMIBILITY RATING | UL 94-V0 Approval MIN. |
| DIMENSION TOLERANCE | |
| Outline dimension: | 0.0059" (0.15mm) |
| Board plating: | 0.0030" (0.076mm) |
| Drill tolerance: | 0.002" (0.05mm) |
| TEST | 100% Electrical Test prior shipment |
| TYPE OF ARTWORK TO BE SUPPLIED | email file, Gerber RS-274-X, PCBDOC etc |
| SERVICE AREA | Worldwide, Globally. |
1.5 Characteristic Impedance
The characteristic impedance of the conductor on the printed
circuit board is an important indicator of the circuit design,
especially in the PCB design of high frequency circuit. Whether the
characteristic impedance of the conductor is consistent and
matching with the characteristic impedance required by the device
or signal must be taken into consideration. Therefore, these two
concepts in reliability design of PCB design must be paid
attention.
There will be a variety of signal transmission in the conductor of
circuit board. To increase the rate of transmission, it must
increase its frequency. Due to the factors of the circuit itself
such as etching, stack thickness, track width and so on are
different, it will cause changes of the impedance value, resulting
in its signal distortion. Therefore, the impedance value of
conductor on high-speed circuit board should be controlled within a
certain range, known as the "impedance control". The factors that
affect the impedance of the PCB wiring are mainly the width of the
copper track, the thickness of the copper track, the dielectric
constant of the dielectric, the thickness of the dielectric, the
thickness of the pad, the path of the ground layer, the wires
around the wiring, etc. So the impedance of the wiring on the board
must be controlled in the design of the PCB to avoid signal
reflection and other electromagnetic interference and signal
integrity issues as far as possible, to guarantee the stability of
the actual use of the PCB board. You can refer to the corresponding
empirical formula for the calculation method of micro-strip line
and strip line impedance on PCB board.
