This site was designed with the
.com
website builder. Create your website today.
Start Now

Ladybird

Preschool

Bruton

 

 

“Enrichment beyond the classroom”

CALL US: 01749 813164

0
  • HOME

  • ABOUT

  • CURRICULUM

    • SEND - Local Offer
    • POLICIES
    • Fun
    • Ofsted Report
    • New Page
  • LIFE AT LADYBIRDS

  • OUR CELEBRATIONS

  • PARENTS

  • THE STAFF

  • CONTACT US

  • Forum

  • Members

  • Shop

  • More

    Use tab to navigate through the menu items.
    4 1 The Role of the Key Person and Settl
    4 1 The Role of the Key Person and Settl
    To see this working, head to your live site.
    • All Posts
    • My Posts
    zltmsmile
    Jul 10, 2021

    What is the reason why PCBA processing circuit board is not easy to tin

    in General Discussions

    Why is it not easy to tin on some china pcb assembly board pads? Here, Shenzhen PCBA processing factory POE Technology will give you an analysis of the possible reasons.

    The first reason is: we need to consider whether it is a customer design problem, and we need to check whether there is a connection between the pad and the copper skin, which will cause the pad to be insufficiently heated.

    The second reason is: whether there are customer operational problems. If the welding method is wrong, it will affect the heating power, the temperature is not enough, and the contact time is not enough.

    The third reason is: the problem of improper storage.

    ①Under normal circumstances, the tin spray surface will be completely oxidized in about a week or even shorter

    ②OSP surface treatment process can be stored for about 3 months

    ③Long-term preservation of immersion gold plate

    The fourth reason is: the problem of flux.

    ①Insufficient activity, unable to completely remove the oxide material on the PCB pad or SMD soldering position

    ②The amount of solder paste at the solder joint is not enough, and the wetting performance of the flux in the solder paste is not good

    ③The tin on some solder joints is not full, and the flux and tin powder may not be fully fused before using;

    The fifth reason is: the problem handled by the board factory. There is oily substance on the pad that has not been removed, and the pad surface has not been oxidized before leaving the factory.

    The sixth reason is: the problem of Flexible PCB reflow soldering. If the preheating time is too long or the preheating temperature is too high, the activation of the flux will be invalid; the temperature is too low or the speed is too fast, and the tin does not melt.


    2 comments
    0
    robinjack529
    Jul 15, 2021

    The first reason is: we need to consider whether it is a customer design problem, educationportalonline will check this for us and then we will be able to tell you about the problem.

    0
    hefibiv264
    Mar 29

    Choose any type of writing homework, and a topic-savvy online paper writer will start working on it from papernow reviews the ground up. With the help of our paper writing service, obtain original research and well-written texts.

    0
    2 comments

    Call Us: 01749 813146   / berniepage58@yahoo.co.uk  /  Jubilee Park Pavilion, Coxs Close, Bruton, Somerset BA10 0NS

    • HOME

    • ABOUT

    • CURRICULUM

      • SEND - Local Offer
      • POLICIES
      • Fun
      • Ofsted Report
      • New Page
    • LIFE AT LADYBIRDS

    • OUR CELEBRATIONS

    • PARENTS

    • THE STAFF

    • CONTACT US

    • Forum

    • Members

    • Shop

    • More

      Use tab to navigate through the menu items.