国产国产人在线成免费视频

    <var id="tbxrt"><ins id="tbxrt"></ins></var>

        <big id="tbxrt"><listing id="tbxrt"></listing></big>
          <span id="tbxrt"><menuitem id="tbxrt"><dfn id="tbxrt"></dfn></menuitem></span>

          Shenzhen Grande Electronic Linkedin Page
          Shenzhen Grande Electronic Co., Ltd logo
          E-mail us for a Quote:
          sales88@greattong.com
          Call us now:
          +86-755-83261869

          Technical Article


          PCB Assembly: Exposed Vias in BGA Pads

          Time:2017-05-03 14:57:40 Click:

          Open or exposed vias are never put in BGA pads. However, it is permitted to place them between the pads if a complete solder mask dam is inserted between the pad and the via. You can also instruct your PCBA assembly house to fill and plate the vias, but only use metal on the PGA pad. 

          You have more flexibility when using other types of components. But you have to make some choices and follow accepted guidelines. Let use consider a large part, such as a voltage regulator, where the vendor advises to connect vias to the thermal pad in the ground plane, or on the back side of the board in the thermal area. For this application, it is similar to the way a QFN is treated; read our recommendations regarding that type of package. 

          In applications where you have a lot of room, which gives you flexibility, if you have exposed vias, you may experience that solder is pulled to the reverse side of the board. This is okay if the vias are very small. However, this is not a wise practice. 

          Your choices come with pluses and minuses. For example, some manufacturing engineers recommend that a via should never be filled or capped because it would inhibit the transfer of heat. Conversely, power component vendors say you should not use an un-manufacturable design to meet product design requirements. The best choice is to cap the via with solder mask, but make it as small as possible (i.e., 100-125 microns bigger than the via). You should section off the paste stencil layer in segments. Remember, problems may occur if solder paste is placed on top of an exposed via or masked via.

          Previous:PCB Layout: Essential PCB Design Rules

          Next:Fiducial Mark for PCB Assembly Alignment


          Request an Official Quote

          Questions

          E-MAIL

          File Upload

          Upload a list of files

            Please upload your Gerber files and BOM. You can upload an unlimited number of files as long as the total size of all files does not exceed 20 MB. To ensure you receive your official quote in less than 24 hours, please include the quantity of circuit boards for which you would like a quote.

            If you require that we sign a Non-Disclosure Agreement (NDA), please send it to us prior to sending your files and we will be happy to accommodate.

             
            Home About Us Services Quality Pb-Free News Contact Us


            Copyright ® 2017,Shenzhen Grande Electronic Co., Ltd. All Rights Reserved. 中文站 Sitemap

            国产国产人在线成免费视频

              <var id="tbxrt"><ins id="tbxrt"></ins></var>

                  <big id="tbxrt"><listing id="tbxrt"></listing></big>
                    <span id="tbxrt"><menuitem id="tbxrt"><dfn id="tbxrt"></dfn></menuitem></span>