Application note APT0503 December 2005 Generic specification Baseplate flatness of power modules Advanced Power Technology Europe Chemin de Magret 33 700 Mérignac, France Otherwise indicated on the module datasheet, the baseplate flatness is defined by the following : Overall convex shape : Module is designed to get an overall convex shape of the baseplate in order to improve the contact with the heatsink after mounting. The convex shape is tested by measuring the bow between the middle of the module baseplate and the surround (measurement in the Length and the Width of the base, as shown on Fig. 1) Due to the specificity of each design, (substrates layout, die location, die size), some cavities can occur in the profile of the baseplate, observed from the bottom. These cavities have very limited depth due to the overall shape of the baseplate and will have insignificant impact on module performance due the materials characteristics, assuming that the module is mounted onto the heatsink according our mounting recommendations (aspects of silicone grease, heatsink flatness, mounting torque, etc …) Fig. 1 Maximum convexity per package type, for modules built with copper baseplate : (values in µm) Package J1 J3 LP2 LP4 LP8 LP8W SP3 SP4 SP6 SP6-P In Length 120 140 110 100 140 140 90 120 140 140 In Width 40 80 50 80 110 110 50 50 80 80 Values for E2 E3 P2 P3 and D1 D3 D4 are specifically defined in the module datasheet C H E M I N D E M AG R E T - 3 3 7 0 0 M E R I G N AC F R A N C E - T E L: 3 3 ( 0 ) 5 5 7 9 2 1 5 1 5 - FA X : 3 3 ( 0 ) 5 5 6 4 7 9 7 6 1 S . A . S . A U C A P I TA L D E 1 0 0 8 9 0 0 - R.C. BORDEAUX 83B35 - SIRET 326 116 514 00018 A P E 3 2 1 C - N ° TV A FR 8 5 3 2 6 1 1 6 5 1 4