SMT Soldering Handbook surface mount technology 2nd phần 5 potx

... identical with a reflowsoldering oven (Section 5. 4.4). It must be remembered, however, that with Wavesoldering 1 45 job:LAY 05 page:2 colour:1 black–text 5 Reflowsoldering 5. 1 The reflow concept As ... solder): Solders to ISO 9 453 : 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 an Ag cont...

Ngày tải lên: 08/08/2014, 03:20

... have two pumps, one for each wave, but both Wavesoldering 111 job:LAY04 page:36 colour:1 black–text 4 .5 Wavesoldering in an oxygen-free atmosphere 4 .5. 1 Origins and development Normal non-industrial ... existing tin-oxide or lead-oxide layers by adding between 5% and 25% vol hydrogen to the nitrogen soldering atmosphere requires temperatures above 350 °C/660 °F, which are not pract...

Ngày tải lên: 08/08/2014, 03:20

... fluxes 50 3.4 .5 Low-solids and no-clean fluxes 52 3.4.6 Watersoluble fluxes 53 3.4.7 Solvents used in fluxes 54 3.4.8 Flux standards 54 3.4.9 Testing soldering fluxes 57 3 .5 Soldering heat 60 3 .5. 1 ... W,R 0.12 ; 0. 05 SO, 6–28 1.27/ 4.0 ; 5. 0/ W,R SOIC 0. 050 16 ; 0.2 to 7.6 ; 18/ 0.3 ; 0.72 VSO 40 56 0. 75/ up to 11 ; 21/ W,R 0.030 0.44 ; 0. 85 SOJ, 20–84 1.27/ up to W,...

Ngày tải lên: 08/08/2014, 03:20

... 480–900 O0.1 Vapour phase 25 40 sec 2 15 419 0.7–1 .5 Infrared and/or convection 15 30 sec 250 –300 480 57 0 0 .5 1 .5 Impulse 0 .5 3 sec 250 –300 480 57 0 0.1–1.0 grain structure of the joint, and the ... thickness Soldering method Confrontation Temperature Zone period °C °F thickness m Wavesoldering 2 5 sec 250 480 0.3–0.8 Reflow: Laser 0.02–0.04 sec 250 – 350 480–900 O0.1 Vapour...

Ngày tải lên: 08/08/2014, 03:20

... substrates Substrate Leaching rate in 60% Sn/40% Pb solder (m/sec) at 2 15 °C/420 °F at 250 °C/480 °F Au 1.7 5. 25 Ag 0. 75 1.6 Cu 0.0 75 0. 15 Pd 0.0 25 0.0 75 Ni, Pt 0.01 0.01 compelling technical reason for them, ... sec vapourphase soldering 420 °F+/ 5 °F Solderability in 250 °C+/ 5 °C 2 sec wavesoldering 480 °F+/−10 °F Tendency to dewet 260 °C+/ 5 °C 5 sec 50 0 °F+/...

Ngày tải lên: 08/08/2014, 03:20

... distance (‘snap-off’) from Reflowsoldering 1 75 job:LAY 05 page:40 colour:1 black–text Figure 5. 10 In-line vapourphase soldering system 5. 4 .5 ‘New-generation’ vapourphase soldering systems The preheat ... systems. 188 Reflowsoldering job:LAY 05 page:49 colour:1 black–text Table 5. 10 Emitter temperatures and wavelength pattern of the emitted radiation Temperature °C 250 300 350 50...

Ngày tải lên: 08/08/2014, 03:20

... Proc. Electronic Comps. and Technology Conf., pp. 50 7 51 0. 37. Lea, C. (1989) Lasersoldering – Production and Microstructural Benefits for SMT. Soldering and Surface Mounting Technology, No. 2, pp. ... Variations in Soldering and their Influence on Microstructure and Strength of Solder Joints. Soldering and Surface Mount Technology, No. 5, pp. 15 20. 34. Volk, H. (1990) loc...

Ngày tải lên: 08/08/2014, 03:20

... 8.6 Height of various surface features on a circuit board. Footprints and tracks 35 1 35  m/1 .5 5. 5 mil; soldermask lacquer 10–20  m/0.4–0.8 mil; solder- mask dry-film 50 –100  m/2–4 mil Figure ... 255 job:LAY08 page:10 colour:1 black–text Figure 8 .5 Stand-off heights of various SMDs. (a) Chip resistors and ceramic condensers 25  m/1 mil; TA condensers 100  m/4 mil; (b) SOTs 1 2...

Ngày tải lên: 08/08/2014, 03:20

... batch cleaning installation can be reckoned between 5 sq. m to 25sq. m/ 45 sq. ft to 2 25 sq. ft of board area, occupying lengths from 5 m/ 15 ft to 6 .5 m/20 ft. A simple, compact and low-cost but very ... in detail in Section 3.3 .5. See also References 22 and 23 of Chapter 3. 9.2 Soldering success and soldering perfection 9.2.1 Soldering success and soldering faults In so...

Ngày tải lên: 08/08/2014, 03:20

... rosin/resin fluxes, 51 alcohol-based fluxes, 54 demands to be met, 48, 49 functions, 45 47 low-solids fluxes, 52 no-clean fluxes, 52 , 53 rosin/resin fluxes, 50 , 51 watersoluble fluxes, 53 Soldering imperfections ... insulation resistance, 59 , 321 tackiness, 60 Soldering flux tests: Beilstein test for halide presence, 59 corrosion test, 58 halide test, 58 silver-chromate te...

Ngày tải lên: 08/08/2014, 03:20