Placement file: Есть вопрос. Опции

[doomer#gp]

Экспортирую из Allegro 15.x Placement File (текстовый файл к оординтами).

При экспорте placement файла надо выбрать Placement Origin.
Так вот куда следует ставит Placement Origin:

1.SMD компонты с малым числом выводов(пассив,soic tssop)
- в геометрический центр; на pin ?

2. PQFP, BGA, QFN - в геом. центр; на fiducial point ?

[Nixon]

Судя по рекомендациям IPC на геометрический центр посадочного места (не корпуса, хотя почти всегда они совпадают).
Посмотрите дополнительно информацию по созданию библиотек на www.PCBLibraries.com

В догонку из книги "Defining a CAD library":

Код

5    ORIGIN LOCATION

The Origin location for all “active” Surface Mount devices should be the centroid to accommodate Pick and Place assembly equipment. This also aids the part placement phase in PCB design layout when rotating land patterns using CAD tools.

The Origin location for all “active” Through Hole devices should be the centroid to accommodate Pick and Place assembly equipment. This also aids the part placement phase in PCB design layout when rotating land patterns using CAD tools.

The Origin Location for Connectors should be whatever makes the most common sense.
Examples:
a.    If the connector is a Front/Back Panel type (RJ45, USB, DB-Type, DIN, Power Jack, etc.) and is mounted on the edge of the PC Board, the origin should be located on the edge of the board in the center of the connector.
b.    If the connector is an “On Board” Header, Memory Socket, PCI, etc. Through Hole the origin could be on Pin 1 to keep the pins on a common grid for trace routing.
c.    If the connector is Surface Mount the origin could be centroid to accommodate Pick and Place assembly equipment.

[doomer#gp]

Could i download this book anywhere ?
Is it located on our ftp ?