SMT Soldering Handbook surface mount technology 2nd phần 6 doc

... footprints 2 06 Reflowsoldering job:LAY05 page: 46 colour:1 black–text Table 5.9 Relationship between surface temperature and emitted thermal energy. Values taken from NASA Document TT-F-783 Surface ... energy: watt/cm 0.43 0 .60 0.89 2.0 5.1 watt/in 2.58 3 .60 5.34 12.0 30 .6 kw/m 4.3 6. 0 8.9 20 51 Wavelength of 5.5 m 5.0 m 4 .6 m 3.7 m 2.4 m the energy maximum:  max Emitte...

Ngày tải lên: 08/08/2014, 03:20

... options 61 3 .6 Solderability 63 3 .6. 1 Wetting and dewetting 63 3 .6. 2 Capillarity and its effects 65 3 .6. 3 Capillarity and joint configuration 65 3 .6. 4 The importance of solderability 69 3 .6. 5 Oxide ... 3 26 9.2 Soldering success and soldering perfection 327 9.2.1 Soldering success and soldering faults 327 9.2.2 Soldering perfection and soldering imperfection...

Ngày tải lên: 08/08/2014, 03:20

... sphere: in effect, the surface behaves like a tensioned skin which encloses the molten solder, hence the term surface tension’ (Figure 3.11). Surface tension, tending to reduce the surface of a given ... wavesoldering soldering iron together with a metered amount of flux-cored solderwire to joints on three-dimensional assemblies, which because of their geometry do not lend them- selves...

Ngày tải lên: 08/08/2014, 03:20

... (Figure 3.14). Wavesoldering, vapourphase soldering, hot air or gas convection soldering, impulse soldering and handsoldering with a soldering iron present equilibrium Soldering 61 job:LAY03 page:41 ... 11.2.2. 66 Soldering job:LAY03 page:44 colour:1 black–text Figure 3.14 Equilibrium and non-equilibrium heating situations heating conditions. Infrared soldering, laser solderin...

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... contamination may be washed off the board surface back into the fluxer. 96 Wavesoldering job:LAY04 page:31 colour:1 black–text Figure 4.20 Single-wave soldering with a counterflow jetwave single ... be achieved with a 112 Wavesoldering job:LAY04 page:44 colour:1 black–text 4 .6 Board conveyor systems 4 .6. 1 Functional requirements Boards must travel through a wavesoldering unit at a know...

Ngày tải lên: 08/08/2014, 03:20

... beneficial effect of silver in solder): Solders to ISO 9453: I. 62 .5% 63 .5% Sn II. 61 .5% 62 .5% Sn, 1.8%–2.2% Ag* melting point 183 °C/ 361 – 361 °F melting point 178 °C/352 °F *The old DIN 1707 specified ... 0 06 To ISO 9453 Particle: size 6 ranges 3 ranges shape Spherical or elliptical Only spherical surface No ‘satellites’ Not specified Flux: To J-STD 004 To ISO 9454–1 Paste: Meta...

Ngày tải lên: 08/08/2014, 03:20

... (1990) Development of a fluxless soldering process for surface mount technology. Soldering and Surface Mount Technology, No. 4, pp. 23– 26. See also USP 4. 960 .2 36. 33. Nylen, M. and Norgren, S. ... Proc. Electronic Comps. and Technology Conf., pp. 507–510. 37. Lea, C. (1989) Lasersoldering – Production and Microstructural Benefits for SMT. Soldering and Surface Mounting...

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... after soldering 263 job:LAY08 page:17 colour:1 black–text Cleaning after soldering or ‘defluxing’, in spite of the growing use of no-clean fluxes, is still an important aspect of soldering technology. ... to deal with this problem (see Section 8.3.3). 266 Cleaning after soldering job:LAY08 page:9 colour:1 black–text Vapourphase soldering and reflow soldering in a nitrogen atmosphe...

Ngày tải lên: 08/08/2014, 03:20

... = 1.0) (years) CFC 113 47 .6 °C/117.7 °F 27 90 0.85 1.3 CHC 111 74.1 °C/ 165 .4 °F 124 6. 3 0.13 0.02 HCFC 123 28.0 °C/82.4 °F 68 1 .6 0.02 0.02 HCFC 141b 32.0°C/89 .6 °F 61 12 0.15 0.18 123/141b- ... to Soldering Science and Technology Club, 9 December, Teddington, England. 2. Lea, C. (1988) A Scientific Guide to Surface Mount Technology, Electrochemical Publications, Ayr, Scot...

Ngày tải lên: 08/08/2014, 03:20

... influenced by: corrosion aspects, 263 , 265 general considerations, 261 – 263 its operating environment, 263 , 264 the marketplace, 266 the nature of the endproduct, 265 – 266 Cleanliness after cleaning: definition, ... protion, 164 , 165 metal content, 160 , 161 operational requirements, 158, 159, 165 print-down thickness, 172, 173 screen printing, 175, 1 76 single-spot dispensing, 16...

Ngày tải lên: 08/08/2014, 03:20