SMT异常处理培训资料
<p>突然翻出来的 以前在做制程的时候做的培训资料</p><p>拿出来分享一下，算不上什么好的东西</p><p>既然上传不了，那就贴出来吧。。。。</p>[此贴子已经被作者于2009-11-27 11:27:29编辑过] 没看到 <p>我晕 </p><p>500多K 的都不让我上传</p><p></p> <p> </p><div class="O" vshape="_x0000_s1026" style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="FONT-FAMILY: 隶书; COLOR: red; FONT-SIZE: 24pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN; text-shadow: auto;">1.焊锡珠产生的原因及</span><span lang="ZH-TW" style="FONT-FAMILY: 隶书; COLOR: red; FONT-SIZE: 24pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; text-shadow: auto; mso-ansi-language: EN-US;">處理</span><span style="FONT-FAMILY: 隶书; COLOR: red; FONT-SIZE: 24pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; text-shadow: auto;">：</span></div><p> <span style="FONT-FAMILY: 隶书; COLOR: #3333cc; FONT-SIZE: 20pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>因素一：</b></span><span style="FONT-FAMILY: 隶书; COLOR: red; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b><font size="4"><font size="5">焊膏的选用直接影响到焊接质量</font> </font></b></span></p><div class="O" vshape="_x0000_s1026"><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><font size="4"><span style="FONT-FAMILY: "Times New Roman"; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b><span style="mso-spacerun: yes;"> </span></b></span></font><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b><font size="5">焊膏中金属的含量、焊膏的氧化度，焊膏中合金焊料粉的粒度度都能影响焊珠的产</font></b></span><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b><font size="5">生。</font> </b></span></div><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: "Times New Roman"; COLOR: #3333cc; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b><span style="mso-spacerun: yes;"> </span></b></span><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; COLOR: #3333cc; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>a.</b></span><span style="FONT-FAMILY: 隶书; COLOR: #3333cc; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>焊膏的金属含量</b></span><span style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b> </b></span><span lang="EN-US" style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>(焊膏中金属含量其质量比约为88％～92％，体积比约为50%。当金属含量增</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>加时，焊膏的黏度增加，就能有效地抵抗预热过程中汽化产生的力。另外，金属含量的增加，使</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>金属粉末排列紧密，使其在熔化时更容结合而不被吹散。此外，金属含量的增加也可能减小焊膏</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>印刷后的</b></span><span style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>“</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>塌落</b></span><span style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>”</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>，因此，不易产生焊锡珠。)</b></span><span lang="EN-US" style="FONT-FAMILY: 隶书; COLOR: red; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-TW;"><b> </b></span></div><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; COLOR: #3333cc; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b><span style="mso-spacerun: yes;"> </span></b></span><span lang="EN-US" style="FONT-FAMILY: 隶书; COLOR: #3333cc; FONT-SIZE: 16pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>b.焊膏的金属氧化度</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>在焊膏中，金属氧化度越高在焊接时金属粉末结合阻力越大，焊膏与焊盘</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>及元件之间就越不浸润，从而导致可焊性降低。实验表明：焊锡珠的发生率与金属粉末的氧化度</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>成正比。一般的，焊膏中的焊料氧化度应控制在0.05％以下，最大极限为0.15％。</b></span><span lang="EN-US" style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b> </b></span></div><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"> <span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; COLOR: #3333cc; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>c.</b></span><span style="FONT-FAMILY: 隶书; COLOR: #3333cc; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>錫膏中金属粉末的粒度</b></span><span style="FONT-FAMILY: "Times New Roman"; COLOR: #ff6600; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b><span style="mso-spacerun: yes;"> </span></b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>錫膏中粉末的粒度越小，錫膏的总体表面积就越大，从而导致较细粉末的氧化度较高，因而焊</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>锡珠现象加剧。我们的实验表明：选用较细颗粒度的錫膏时，更容易产生焊锡粉。 </b></span><div class="O" vshape="_x0000_s1026"><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; COLOR: #3333cc; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b><span style="mso-spacerun: yes;"> </span>d.</b></span><span style="FONT-FAMILY: 隶书; COLOR: #3333cc; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>錫膏中助焊剂的量及焊剂的活性</b></span><span style="FONT-FAMILY: "Times New Roman"; COLOR: #ff6600; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b><span style="mso-spacerun: yes;"> </span></b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>焊剂量太多，会造成錫膏的局部塌落，从而使锡珠容易产生。另外，焊剂的活性小时，焊剂的</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>去氧化能力弱，从而也容易产生锡珠。免清洗錫膏的活性较松香型和水溶型錫膏要低，因此就更</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>有可能产生锡珠。 </b></span><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; COLOR: #3333cc; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>e. </b></span><span style="FONT-FAMILY: 隶书; COLOR: #3333cc; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>其它注意事项 </b></span><span style="FONT-FAMILY: "Times New Roman"; COLOR: #3333cc; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b><span style="mso-spacerun: yes;"> </span></b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>此外，錫膏在使用前，一般冷藏在冰箱中，取出来以后应该使其恢复到室温后打开使用，否</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>则，錫膏容易吸收水分，在再流焊锡飞溅而产生锡珠。</b></span></div><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"></div></div></span></div><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"></div></div>
[此贴子已经被作者于2009-11-27 11:33:05编辑过] <span style="FONT-FAMILY: 隶书; COLOR: #3333cc; FONT-SIZE: 20pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>因素二</b></span><span style="FONT-FAMILY: 宋体; COLOR: #3333cc; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 宋体; mso-hansi-font-family: "Times New Roman";"><b>：</b></span><font size="6"><span style="FONT-FAMILY: 隶书; COLOR: red; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>模板的制作及开口</b></span><span style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 新細明體; mso-hansi-font-family: "Times New Roman";"> </span></font><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"> <div class="O" vshape="_x0000_s1026"><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; COLOR: #3333cc; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>a.</b></span><span style="FONT-FAMILY: 隶书; COLOR: #3333cc; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>模板的开口 </b></span></div><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>我们一般根据印制板上的焊盘来制作模板，所以模板的开口就是焊盘的大小。在印刷錫膏时，容</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>易把錫膏印刷到阻焊层上，从而在再流焊时产生锡珠。因此，</b></span><span style="FONT-FAMILY: 隶书; COLOR: red; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>我们可以这样来制作模板，把模板</b></span><span style="FONT-FAMILY: 隶书; COLOR: red; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>的开口比焊盘的实际尺寸减小</b></span><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; COLOR: red; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>10</b></span><span style="FONT-FAMILY: 隶书; COLOR: red; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>％，另外，可以更改开口的外形来达到理想的效果。<br/></b></span><span lang="EN-US" style="FONT-FAMILY: 隶书; COLOR: red; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b></b></span></div><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; COLOR: #3333cc; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b><span style="mso-spacerun: yes;"> </span>b.</b></span><span style="FONT-FAMILY: 隶书; COLOR: #3333cc; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>模板的厚度 </b></span></div><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>錫膏在印制板上的印刷厚度。焊膏印刷后的厚度是漏板印刷的一个重要参数，通常在</b></span><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>0.13mm-</b></span><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>0.17mm</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>之间。焊膏过厚会造成錫膏的</b></span><span style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>“</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>塌落</b></span><span style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>”</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>，促进锡珠的产生。 </b></span></div><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"></div></div></div>
[此贴子已经被作者于2009-11-27 11:33:34编辑过] <span style="FONT-FAMILY: 隶书; COLOR: #3333cc; FONT-SIZE: 20pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>因素三</b></span><span style="FONT-FAMILY: 宋体; COLOR: #3333cc; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 宋体; mso-hansi-font-family: "Times New Roman";"><b>：</b></span><span style="FONT-FAMILY: "Times New Roman"; COLOR: #ff6600; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 宋体; mso-hansi-font-family: "Times New Roman";"><b> </b></span><span style="FONT-FAMILY: 隶书; COLOR: red; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b><font size="6">贴片机的贴装压力</font> </b></span><div class="O" vshape="_x0000_s1026"><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b><span style="mso-spacerun: yes;"> </span></b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>如果在贴装时压力太高，錫膏就容易被挤压到元件下面的阻焊层上，在再流焊时焊锡熔化跑</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>到元件的周围形成锡珠。</b></span><span style="FONT-FAMILY: 隶书; COLOR: red; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>解决方法可以减小贴装时的压力，并采用合适的模板开口形式，避免錫</b></span><span style="FONT-FAMILY: 隶书; COLOR: red; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>膏被挤压到焊盘外边去。</b></span><span style="FONT-FAMILY: "Times New Roman"; COLOR: red; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b> </b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: "Times New Roman"; COLOR: red; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><font color="#000000" size="3"> </font><div class="O" vshape="_x0000_s1026"><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><strong><span style="FONT-FAMILY: 隶书; COLOR: #3333cc; FONT-SIZE: 20pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";">因素四</span><span style="FONT-FAMILY: 宋体; COLOR: #3333cc; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 宋体; mso-hansi-font-family: "Times New Roman";">：</span><span style="FONT-FAMILY: 隶书; COLOR: red; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><font size="6">炉温曲线的设置 </font></span></strong></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><strong><span style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><span style="mso-spacerun: yes;"> </span></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";">锡珠是在印制板通过再流焊时产生的，在预热阶段使錫膏和元件及焊盘的温度上升到</span><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;">120C—</span><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;">150C</span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";">之间，减小元器件在再流时的热冲击，在这个阶段，錫膏中的焊剂开始汽化，从而可能使小</span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";">颗粒金属分开跑到元件的底下，在再流时跑到元件周围形成锡珠。</span><span style="FONT-FAMILY: 隶书; COLOR: red; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";">在这一阶段，温度上升不能太</span><span style="FONT-FAMILY: 隶书; COLOR: red; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";">快，一般应小于</span><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; COLOR: red; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-TW;">2.0</span><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; COLOR: red; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;">C/s</span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";">，过快容易造成焊锡飞溅，形成锡珠。所以应该调整再流焊的温度曲线，采</span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";">取较适中的预热温度和预热速度来控制锡珠的产生。</span><span style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"> </span></strong></div><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"></div></div></span></div><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"></div></div>
[此贴子已经被作者于2009-11-27 11:34:03编辑过] <div class="O" vshape="_x0000_s1026"><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 隶书; COLOR: #3333cc; FONT-SIZE: 20pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>锡珠产生的其他外界因素的影响： </b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b><span style="mso-spacerun: yes;"> </span></b></span><font size="5"><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>一般</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>錫</b></span><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>膏印刷时的最佳温度为</b></span><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>25C+-3C</b></span><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>，湿度为相对湿度</b></span><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>40%-60</b></span><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>％，温度过高，</b></span><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>使</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>錫</b></span><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>膏的黏度降低，容易产生</b></span><span style="FONT-FAMILY: "Times New Roman"; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>“</b></span><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>塌落</b></span><span style="FONT-FAMILY: "Times New Roman"; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>”</b></span><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>，湿度过高，</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>錫</b></span><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>膏容易吸收水分，容易发生飞溅，</b></span><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>这都是引起锡珠的原因。另外，印制板暴露在空气中较长的时间会吸收水分，并发生焊</b></span></font><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b><font size="5">盘氧化，可焊性变差</font>。 </b></span></div><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"></div></div>
[此贴子已经被作者于2009-11-27 11:32:20编辑过] <div class="O" vshape="_x0000_s1026"><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="FONT-FAMILY: 隶书; COLOR: red; FONT-SIZE: 24pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN; text-shadow: auto;"><i>2.立碑问题分析及处理 </i></span></div><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"> <div class="O" vshape="_x0000_s1026" style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 隶书; FONT-SIZE: 20pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; text-shadow: auto;"><b>矩形片式元件的一端焊接在焊盘上，而另一端则翘立，这种现象就称为立碑。引起该种现象主要原因是锡膏熔化时元件两端受力不均匀所致。 </b></span></div><div class="O" vshape="_x0000_s1026" style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 隶书; FONT-SIZE: 20pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; text-shadow: auto;"><font size="3"> </font><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>产生的原因：</b></span></span></div><div class="O" vshape="_x0000_s1026" style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 隶书; FONT-SIZE: 20pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; text-shadow: auto;"><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><font size="3"> </font><div class="O" vshape="_x0000_s1026"><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1; mso-text-indent-alt: 224;"><span style="FONT-FAMILY: 隶书; COLOR: #3333cc; FONT-SIZE: 20pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>因素一：</b></span><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>热效能不均匀，焊点熔化速率不同</b></span><span lang="ZH-CN" style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-TW;"><b> </b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1; mso-text-indent-alt: 224;"><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b></b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1; mso-text-indent-alt: 224;"><span style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b><span style="mso-spacerun: yes;"> </span></b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>我们设想在再流焊炉中有一条横跨炉子宽度的再流焊限线，一旦錫膏通过它就会立即熔化。</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>片式矩形元件的一个端头先通过再流焊限线，錫膏先熔化，完全浸润元件的金属表面，具有液态</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>表面张力；而另一端未达到</b></span><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>183</b></span><span lang="EN-US" style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>°</b></span><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>C</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>液相温度，錫膏未熔化，只有焊剂的粘接力，该力远小于再流</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>焊錫膏的表面张力，因而，使未熔化端的元件端头向上直立。因此，保持元件两端同时进入再流</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>焊限线，使两端焊盘上的錫膏同时熔化，形成均衡的液态表面张力，保持元件位置不变。 </b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1; mso-text-indent-alt: 224;"><span lang="EN-US" style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b></b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1; mso-text-indent-alt: 224;"><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>a.PCB<span style="mso-spacerun: yes;"> </span>pad</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>大小不一，可使零件两端受热不均； </b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1; mso-text-indent-alt: 224;"><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>b.PCB<span style="mso-spacerun: yes;"> </span>pad</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>分布不当（</b></span><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>pad</b></span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>一端独立，另一端与大铜面共累）</b></span></div></div></span><div class="O" vshape="_x0000_s1026" style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><strong></strong></span></div></span></div><div class="O" vshape="_x0000_s1026" style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><strong></strong></span></div></div></div> <div class="O" vshape="_x0000_s1026"><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 隶书; COLOR: #3333cc; FONT-SIZE: 20pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>因素二：</b></span><font size="5"><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>元器件两个焊端或</b></span><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>PCB</b></span></font><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b><font size="5">焊盘的两点可焊性不均匀</font> </b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b></b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 隶书; COLOR: #3333cc; FONT-SIZE: 20pt; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>因素三：</b></span><span style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b><font size="5">在贴装元件时偏移过大，或錫膏与元件连接面太小 </font></b></span></div><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><font size="5"> </font><div class="O" vshape="_x0000_s1026"><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 隶书; COLOR: red; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b><font size="5">针对以上个因素，可采用以下方法来减少立碑问题： </font></b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b><span style="mso-spacerun: yes;"><font size="5"> </font></span></b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><font size="5"><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b><span style="mso-spacerun: yes;"> </span></b></span><span lang="EN-US" style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>①适当提高回流曲线的温度 </b></span></font></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><font size="5"><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b><span style="mso-spacerun: yes;"> </span></b></span><span lang="EN-US" style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>②严格控制线路板和元器件的可焊性 </b></span></font></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><font size="5"><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b><span style="mso-spacerun: yes;"> </span></b></span><span lang="EN-US" style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>③严格保持各焊接角的锡膏厚度一致 </b></span></font></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><font size="5"><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b><span style="mso-spacerun: yes;"> </span></b></span><span lang="EN-US" style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>④避免环境发生大的变化 </b></span></font></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b><span style="mso-spacerun: yes;"><font size="5"> </font></span></b></span><span lang="EN-US" style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b><font size="5">⑤在回流中控制元器件的偏移</font> </b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="FONT-FAMILY: "Times New Roman"; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b><span style="mso-spacerun: yes;"> </span></b></span><span lang="EN-US" style="FONT-FAMILY: 隶书; mso-ascii-font-family: "Times New Roman"; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN;"><b>⑥提高元器件角与焊盘上锡膏的之间的压力 </b></span></div><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"></div></div></div></div>
[此贴子已经被作者于2009-11-27 11:31:24编辑过] <div class="O" vshape="_x0000_s1026" style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 隶书; COLOR: red; FONT-SIZE: 24pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; text-shadow: auto;"><i>桥接问题：</i></span></div><div class="O" vshape="_x0000_s1026" style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 隶书; COLOR: red; FONT-SIZE: 24pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; text-shadow: auto;"><font color="#000000" size="3"> </font><div class="O" vshape="_x0000_s1026"><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 隶书; COLOR: #3333cc; FONT-SIZE: 20pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman";"><b>产生原因： </b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 隶书; COLOR: #3333cc; FONT-SIZE: 16pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; text-shadow: auto;"><b></b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="FONT-FAMILY: 隶书; FONT-SIZE: 16pt; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN; text-shadow: auto;"><b><span style="mso-spacerun: yes;"> </span></b></span><span lang="EN-US" style="FONT-FAMILY: 隶书; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN; text-shadow: auto;"><b>①由于钢网开孔与焊盘有细小偏差，造成锡膏印刷不良有偏差 </b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="FONT-FAMILY: 隶书; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN; text-shadow: auto;"><b><span style="mso-spacerun: yes;"> </span>②锡膏量太多可能是钢网开孔比例过大 </b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="FONT-FAMILY: 隶书; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN; text-shadow: auto;"><b><span style="mso-spacerun: yes;"> </span>③锡膏塌陷 </b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="FONT-FAMILY: 隶书; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN; text-shadow: auto;"><b><span style="mso-spacerun: yes;"> </span>④锡膏印刷后的形状不好成型差 </b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="FONT-FAMILY: 隶书; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN; text-shadow: auto;"><b><span style="mso-spacerun: yes;"> </span>⑤回流时间过慢 </b></span></div><div style="mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="FONT-FAMILY: 隶书; mso-ascii-font-family: 隶书; mso-fareast-font-family: 隶书; mso-hansi-font-family: "Times New Roman"; mso-fareast-language: ZH-CN; text-shadow: auto;"><b><span style="mso-spacerun: yes;"> </span>⑥元器件与锡膏接触压力过大 </b></span></div><div style="mso-line-spacing: "100 50 0"; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"></div></div></span></div>