 |
поискавой системы для электроныых деталей |
|
|
поискавой системы для электроныых деталей |
|
STPC4HEBI датащи(PDF) 84 Page - STMicroelectronics |
|
|
|||||||||||||||||||||||||||||
STPC4HEBI датащи(HTML) 84 Page - STMicroelectronics |
|
|
84 / 93 page  DESIGN GUIDELINES 84/93 Release 1.5 - January 29, 2002 When considering thermal dissipation, one of the most important parts of the layout is the connection between the ground balls and the ground layer. A 1-wire connection is shown in Figure 6-27. The use of a 8-mil wire results in a thermal resistance of 105°C/W assuming copper is used (418 W/ m.°K). This high value is due to the thickness (34 µm) of the copper on the external side of the PCB. Considering only the central matrix of 36 thermal balls and one via for each ball, the global thermal resistance is 2.9°C/W. This can be easily improved using four 12.5 mil wires to connect to the four vias around the ground pad link as in Figure 6-28. This gives a total of 49 vias and a global resistance for the 36 thermal balls of 0.5°C/ W. The use of a ground plane like in Figure 6-29 is even better. Figure 6-27. Recommended 1-wire Power/Ground Pad Layout Solder Mask (4 mil) Pad for ground ball (diameter = 25 mil) Hole to ground layer (diameter = 12 mil) Connection Wire (width = 12.5 mil) Via (diameter = 24 mil) 1 mil = 0.0254 mm Figure 6-28. Recommended 4-wire Ground Pad Layout 4 via pads for each ground ball |
|
ссылки URL |
| Вашему бизинису помогли Аллдатащит? [ DONATE ] |
Что такое Аллдатащит | реклама | контакт | Конфиденциальность | Ссылка на техническое описание | обмен ссыками | поиск по производителю All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
Russian ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
