Mar07
Why BGA soldering ball always crack(7)? The Bonding force between solder pad of copper foil and PCB substrate

post on March 7, 2023

PCB is composed of layers of Copper Clad Laminate (CCL) and Prepreg (PP) stacked together. In modern PCB manufacturing, CCL has become a standard material. Each CCL manufacturer provides customers with product specifications that indicate the peel strength of the CCL. From these specifications, we can see that the peel strength is higher when using 1.0 oz copper foil thickness than when using 0.5 oz. Different models and manufacturers of CCL also have different peel strengths, so selecting the appropriate CCL specifications is necessary to enhance the bonding force between the copper foil and PCB substrate.

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Design, SMT, Soldering     WorkingBear    Views (3,327)     comment (0)
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Mar01
Why BGA soldering ball always crack(6)? The recommendation of BGA pad design from workingbear

post on March 1, 2023

Below are recommendations for BGA pad design to enhance the soldering strength from Workingbear.

We had several pages talking about the relationship between solder cracking and bonding force. Workingbear personally doesn’t think that making design a change to the pad of PCB can help much with the ability of BGA soldering to resist stress, as it is like a drop in the bucket! A board’s bending or deformation can easily negate all your efforts in improving pad design and solderability. Workingbear still thinks that strengthening the mechanism design and improving the board’s ability to resist bending and deformation is the best solution to fix BGA solder cracking.

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Design, SMT, Soldering     WorkingBear    Views (2,995)     comment (0)
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Feb22
Why BGA soldering ball always crack(5)? Increase the contact area of solder to increase its strength

post on February 22, 2023

In the previous article, we talked about “How to Increase the bonding force for PCBA by using “Copper” base as the PCB surface finish“. Today, we will discuss further how the SMD (Solder Mask Defined) and NSMD (Non-Solder Mask Defined) pad designs of the BGA package affect the solderability and how these two types of pads affect the bonding force of PCA.

Increasing the solder contact area of a component terminal or leads will generally improve the solderability of the component, as it provides more surface area for the solder to wet and bond to the terminal. This can result in a stronger and more reliable solder joint.

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Design, SMT, Soldering     WorkingBear    Views (3,002)     comment (0)
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Feb15
Why BGA soldering ball always crack(4)? Using "copper" base material as the surface finish for PCB

post on February 15, 2023

Following last discussion, we learned that solder cracking is caused when the stress placed upon it exceeds the strength of the bonding force. However, it’s possible to address this issue by increasing the bonding force of the printed circuit board assembly (PCBA). By doing so, we can effectively eliminate solder cracking, making it a more reliable and robust technology for a wide range of applications.

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Design, SMT, Soldering     WorkingBear    Views (2,019)     comment (0)
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Jul22
What purpose of alloy metal of Cu, Ag, Zn, Sb, Bi added to solder paste?

post on July 22, 2021

Tin (Sn) based solder is still the best material for PCB (Printed Circuit Board) assembly in the modern industry today. The only difference is the lead (Pb) free from the solder base due to environmental concerns.

The melting point of tin (Sn) as 231.9°C (equivalent to 505°K)  is hardly accepted by PCB assembly since most electronic components may not sustain such high temperatures. Maybe it shall say there are still lots of electronic components that can’t reach so high-temperature levels today yet. As a result, the solder powder should contain the majority of tin and a few other alloy components, such as copper (Cu), silver (Ag), indium (In), zinc (Zn), antimony (Sb), bismuth (Bi), etc, to reduce the melting point of solder paste and mass-produce the PCB assembly under lower energy.

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Process, Quality, SMT, Soldering     WorkingBear    Views (7,076)     comments (1)
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