<p>元器件封装的构建是PCB设计中的一个重要环节，小小的一个错误很可能导致整个板子都不能工作以及工期的严重延误。常规器件的封装库一般CAD工具都有自带，也可以从器件原厂的设计文档、参考设计源图中获取。</p>
<p><strong>封装名称与图形如下</strong></p>
<p><em><strong>No.1</strong></em></p>
<p><strong><em>晶体管</em></strong></p>
<p><img alt="1" data-entity-type="file" data-entity-uuid="d0ac61c7-67dd-47d5-8f85-98dad871200b" src="/sites/default/files/inline-images/1_55.jpg" /></p>
<p><img alt="2" data-entity-type="file" data-entity-uuid="d05600a6-8eca-43c5-8092-31ad2969ff3d" src="/sites/default/files/inline-images/2_53.jpg" /></p>
<p><img alt="3" data-entity-type="file" data-entity-uuid="e4962e9e-f550-451c-aa3b-3eb44bb1b8b8" src="/sites/default/files/inline-images/3_46.jpg" /></p>
<p><img alt="3" data-entity-type="file" data-entity-uuid="5aed4cb1-23f4-497a-b81c-eb1b8698bcb9" src="/sites/default/files/inline-images/4_43.jpg" /></p>
<p><img alt="1" data-entity-type="file" data-entity-uuid="d1caecd6-848d-4f62-a3d7-742b4547ac74" src="/sites/default/files/inline-images/111111.png" /></p>
<p><em><strong>No.2</strong></em></p>
<p><em><strong>晶振</strong></em></p>
<p><img alt="5" data-entity-type="file" data-entity-uuid="cb8270b7-78fe-4ba2-b643-a12a889c2843" src="/sites/default/files/inline-images/5_39.jpg" /></p>
<p><em><strong>No.3</strong></em></p>
<p><em><strong>电感</strong></em></p>
<p><img alt="6" data-entity-type="file" data-entity-uuid="b9d6e09f-5c5a-4c26-ad0f-d620c5d52eda" src="/sites/default/files/inline-images/6_32.jpg" /></p>
<p><em><strong>No.4</strong></em></p>
<p><em><strong>接插件</strong></em></p>
<p><img alt="7" data-entity-type="file" data-entity-uuid="cd581904-2d12-4d6c-a34a-e212ce3b8062" src="/sites/default/files/inline-images/7_26.jpg" /></p>
<p><img alt="8" data-entity-type="file" data-entity-uuid="0b135e9b-53b1-4e7c-b572-cc9e8c571822" src="/sites/default/files/inline-images/8_19.jpg" /></p>
<p><img alt="9" data-entity-type="file" data-entity-uuid="0332ebba-29b1-4d96-a738-7e9a82e27c91" src="/sites/default/files/inline-images/9_13.jpg" /></p>
<p><img alt="1" data-entity-type="file" data-entity-uuid="fb5dc3e1-2e22-46a8-a48b-a3bb68973ef1" src="/sites/default/files/inline-images/10_15.jpg" /></p>
<p><img alt="1" data-entity-type="file" data-entity-uuid="8163402a-4102-432e-a07e-c9d97b83d758" src="/sites/default/files/inline-images/11_15.jpg" /></p>
<p><em><strong>No.5</strong></em></p>
<p><em><strong>Discrete Components</strong></em></p>
<p><img alt="2" data-entity-type="file" data-entity-uuid="9cc501a4-7d74-4c81-9e7d-5480a77b2549" src="/sites/default/files/inline-images/12_11.jpg" /></p>
<p><img alt="4" data-entity-type="file" data-entity-uuid="8b305cf8-c3b4-47df-bef5-7d73a2d3adec" src="/sites/default/files/inline-images/13_10.jpg" /></p>
<p><img alt="4" data-entity-type="file" data-entity-uuid="c590c8aa-51ae-4d8c-8f0e-eb03b42d8e65" src="/sites/default/files/inline-images/14_9.jpg" /></p>
<p><img alt="5" data-entity-type="file" data-entity-uuid="e07a0c9c-7dc0-4194-afea-1a8744ef020e" src="/sites/default/files/inline-images/15_9.jpg" /></p>
<p><em><strong>No.6</strong></em></p>
<p><em><strong>晶体管</strong></em></p>
<p><img alt="6" data-entity-type="file" data-entity-uuid="170d5f71-2168-4bc5-9e9b-1a34c2c1009e" src="/sites/default/files/inline-images/16_7.jpg" /></p>
<p><img alt="7" data-entity-type="file" data-entity-uuid="9871fe5c-2065-4ac9-b18c-10e801dd0cf7" src="/sites/default/files/inline-images/17_4.jpg" /></p>
<p><em><strong>No.7</strong></em></p>
<p><em><strong>可变电容</strong></em></p>
<p><img alt="8" data-entity-type="file" data-entity-uuid="e1922fc0-22b6-4838-a0be-e5efb822313b" src="/sites/default/files/inline-images/18_4.jpg" /></p>
<p><em><strong>No.8</strong></em></p>
<p><em><strong>数码管</strong></em></p>
<p><img alt="9" data-entity-type="file" data-entity-uuid="3ca9bafd-65eb-4d90-b686-f76188ca129e" src="/sites/default/files/inline-images/19_4.jpg" /></p>
<p><img alt="2" data-entity-type="file" data-entity-uuid="b9964079-7989-46b0-aa1d-442aeae74e70" src="/sites/default/files/inline-images/20_4.jpg" /></p>
<p><em><strong>No.9</strong></em></p>
<p><em><strong>可调电阻</strong></em></p>
<p><img alt="1" data-entity-type="file" data-entity-uuid="dc4d440e-eb56-43de-893c-027ff0a60a66" src="/sites/default/files/inline-images/21_3.jpg" /></p>
<p><em><strong>No.10</strong></em></p>
<p><em><strong>电阻</strong></em></p>
<p><img alt="2" data-entity-type="file" data-entity-uuid="994202c5-4149-46d5-9467-c2c0011cc234" src="/sites/default/files/inline-images/22_2.jpg" /></p>
<p><em><strong>No.11</strong></em></p>
<p><em><strong>排阻</strong></em></p>
<p><img alt="3" data-entity-type="file" data-entity-uuid="8dfb31a0-f5f9-4246-845e-afa8cb0a0a95" src="/sites/default/files/inline-images/23_2.jpg" /></p>
<p><em><strong>No.12</strong></em></p>
<p><em><strong>继电器</strong></em></p>
<p><img alt="4" data-entity-type="file" data-entity-uuid="e0214416-6875-4dcb-a23f-6b2646191383" src="/sites/default/files/inline-images/24_2.jpg" /></p>
<p><img alt="5" data-entity-type="file" data-entity-uuid="cb6d8f8f-03a1-4d11-a5fb-8854e8639769" src="/sites/default/files/inline-images/25_0.jpg" /></p>
<p><em><strong>No.13</strong></em></p>
<p><em><strong>开关</strong></em></p>
<p><img alt="6" data-entity-type="file" data-entity-uuid="c459b185-3fdf-496c-a7f0-747477d39878" src="/sites/default/files/inline-images/26_0.jpg" /></p>
<p><em><strong>No.14</strong></em></p>
<p><em><strong>跳线</strong></em></p>
<p><img alt="7" data-entity-type="file" data-entity-uuid="426a80dd-66e7-4182-bc1c-7c98fdd7bd4e" src="/sites/default/files/inline-images/27.jpg" /></p>
<p><em><strong>No.15</strong></em></p>
<p><em><strong>集成电路</strong></em></p>
<p><img alt="8" data-entity-type="file" data-entity-uuid="76d2f736-60cc-4aca-a856-2c2c30dd66c0" src="/sites/default/files/inline-images/28.jpg" /></p>
<p><em><strong>No.16</strong></em></p>
<p><em><strong>1.5mmBGA</strong></em></p>
<p><img alt="9" data-entity-type="file" data-entity-uuid="ace94073-607d-42a2-b58c-5c2333394391" src="/sites/default/files/inline-images/29.jpg" /></p>
<p><img alt="1" data-entity-type="file" data-entity-uuid="819c9de1-2dc6-4d0d-861b-d116e7d24053" src="/sites/default/files/inline-images/30.jpg" /></p>
<p><em><strong>No.17</strong></em></p>
<p><em><strong>1mmBGA</strong></em></p>
<p><img alt="1" data-entity-type="file" data-entity-uuid="99b99131-0ad9-423e-9d5b-36978c67607e" src="/sites/default/files/inline-images/31_0.jpg" /></p>
<p><em><strong>No.18</strong></em></p>
<p><em><strong>1.27BGA</strong></em></p>
<p><img alt="2" data-entity-type="file" data-entity-uuid="b6b6715b-1a4a-4b5f-88c0-28fe5df5a68a" src="/sites/default/files/inline-images/32_0.jpg" /></p>
<p><img alt="3" data-entity-type="file" data-entity-uuid="a4ff771c-ee63-4988-bdb2-ec2f1bd6d3b0" src="/sites/default/files/inline-images/33_0.jpg" /></p>
<p><img alt="4" data-entity-type="file" data-entity-uuid="8dbb3906-e952-4648-b6d3-f8cff73fe199" src="/sites/default/files/inline-images/34_0.jpg" /></p>
<p><img alt="5" data-entity-type="file" data-entity-uuid="1eb354ce-6c76-46d2-83ad-664b41e89515" src="/sites/default/files/inline-images/35_0.jpg" /></p>
<p><img alt="1" data-entity-type="file" data-entity-uuid="7f4a5f3d-0da1-4eea-85ce-50514f98aeb9" src="/sites/default/files/inline-images/36_0.jpg" /></p>
<p><img alt="1" data-entity-type="file" data-entity-uuid="8490c342-bedb-4578-a5b5-766266b91f4b" src="/sites/default/files/inline-images/37_0.jpg" /></p>
<p><img alt="1" data-entity-type="file" data-entity-uuid="68b8bbf8-22b5-43b5-b858-93d790e45e30" src="/sites/default/files/inline-images/38_0.jpg" /></p>
<p><strong>良好合格的一个器件封装，应该需要满足以下几个条件：</strong></p>
<p>1、设计的焊盘，应能满足目标器件脚位的长、宽和间距的尺寸要求。</p>
<p>特别是要注意：器件引脚本身产生的尺寸误差，在设计时要考虑进去--- 特别是精密、细节的器件和接插件。</p>
<p>不然，有可能会导致不同批次来料的同型号器件，有时候焊接加工良率高，有时候却发生大的生产品质问题！</p>
<p>因此，焊盘的兼容性设计(合适、通用于多数大厂家的器件焊盘尺寸设计），是很重要的!</p>
<p><strong>关于这一点，最简单的要求和检验方法就是：</strong></p>
<p>把实物的目标器件放到PCB板的焊盘上进行观察，如果器件的每个引脚都处在相应的焊盘区域里。</p>
<p>那这个焊盘的封装设计，基本上是没有多大问题。反之，如果部分引脚不在焊盘里，那就不太好，</p>
<p>2、设计的焊盘，应该有明显的方向标识，最好是通用、易辨别的方向极性标识。不然，在没有合格的PCBA实物样品做参考的时候，</p>
<p>第三方（SMT工厂或私人外包）来做焊接加工，就容易发生极性焊反，焊错的问题！</p>
<p>3、设计的焊盘，应该能符合具体那个PCB线路厂本身的加工参数、要求和工艺。</p>
<p>比如，能设计的焊盘线大小、线间距、字符长宽是多少等等。如果PCB尺寸较大，建议大家按市面流行、通用的PCB工厂的工艺进行设计，以因品质或商业合作问题而发生更换PCB供应商的时候，可选择的PCB厂家太少而耽搁了生产进度。</p>
<p>来源：<a href="https://mp.weixin.qq.com/s/skEyH0XyaGFvtDsFhKlkJw">EDN电子技术设计</a></p>