PCB设计规范.doc

IPC - 2152
[This is a working document. It is created for the purpose of review for major
categories. The sections are being incorporated by the IPC Task Group 1-10b.
Comments can be sent to mikej@]
Standard for Determining
Current-Carrying Capacity
In Printed Board Design
1
TABLE OF CONTENTS
1 SCOPE .......................................................... 4
PURPOSE .................................................. 4
DEFINITION OF TERMS................................ 4
APPLICABLE DOCUMENTS ........................... 4
2 CONDUCTOR DESIGN OVERVIEW............ 5
EARLIER CONCEPTS OF CONDUCTOR SIZING
AND CURRENT CARRYING CAPACITY .................... 5
CONDUCTOR SIZING BASED ON CROSS-
SECTIONAL RELATIONSHIP ................................... 5
3 THERMAL MANAGEMENT.......................... 7
BASICS OF HEAT TRANSFER ....................... 7
Conduction...................................... 7
Convection ...................................... 7
Radiation......................................... 8
Heat transfer problem ..................... 8
TEMPERATURE RISE .................................. 9
Steady State ................................... 9
Transient ( add fusing).................... 9
Mounting Configurations................. 9
Altitude Effects ................................ 9
POWER DISSIPATION CONSIDERATIONS .... 10

Power Density ............................... 13
Electrical Resistance ..................... 13
Temperature dependence............. 13
Volume Resistivity ......................... 14
Current........................................... 14
Transient Current Pulses............... 15
Power Dissipation in Copper Planes
15
HIGH SPEED DESIGN CONSIDERATIONS..... 15
Skin Effect and Skin Depth ........... 15
6 CONDUCTOR TEMPERATURE RISE........ 15