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CHAPTER 4 NOTES ON MOUNTING
4.1 Temperature Distribution Due to Mixed Mounting
4.1.2 Distance to adjacent package
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As shown in Figure 4-4, the greater the adjacent distance between devices, the less the temperature difference. Moreover, we can see that temperature differences occur within the same package area. |
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Temperature measurement package: 35 x 35mm 352 pin PBGA Adjacent package: 35 x 35mm 352 pin PBGA |
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Reflow conditions: 232°C to 233°C (peak temperature of BGA ball part) Reflow oven: Air type Conveyor speed: 0.9m/minute Printed wiring board: Number of layers: 4; Material: FR-4; Board thickness: 1.6mm Temperature measurement locations A: Ball part near adjacent package B: Ball part far from adjacent package |
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Figure 4-3. Temperature measurement conditions
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Figure 4-4. Influence of Adjacent Package (Relationship with Distance)
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