lead free solder on regular HASL pads
May. 06, 2024
lead free solder on regular HASL pads
I'm pretty sure remember reading a super old IBM article where they investigated this Bi/Pb mix for some temperature sensitive parts in a mainframe, and it was a disaster. Can't find the article now though
Also from
Quote
If you are looking for more details, kindly visit lead-free hasl.
Caution must be used when using tin / bismuth alloys. It is dangerous to mix tin / bismuth with lead containing alloys. Tin, bismuth, and lead can form a very low melting combination that melts around 95 °C. This could potentially lead to solder joint failure due to natural heating of the assembly during use.
Tin / bismuth alloys are safe to use in combination with other lead free tin-based alloys. In some cases surface mount assemblies are made with SAC305 on the first side and tin / bismuth on the second side. The low reflow temperature for tin / bismuth minimizes intermetallic growth in the SAC305 solder joints and allows for soldering of thermally sensitive components.
Definitelymix Pb solder with the low temp Bismuth-based solders (also there is the different melting point issues, but the alloy that forms is awful). Joint becomes very brittle due to strong intermetallic growth and easy to break with even what I could consider moderate force. For example, with the right (or wrong) mix of solder and a decent grip, I can pull SMD aluminium polymer caps off the board with my bare hands.I'm pretty sure remember reading a super old IBM article where they investigated this Bi/Pb mix for some temperature sensitive parts in a mainframe, and it was a disaster. Can't find the article now thoughAlso from http://www.surfacemountprocess.com/low-temperature-lead-free-solder-paste.html
What is the Difference Between Lead Free HASL and HASL?
With the continuous development of the electronics industry, the technical level of PCB is also rising. Common surface treatment technology include HASL(Lead Free HASL and HASL), immersion gold, gold plating, OSP, etc. HASL is to coat a layer of tin-lead alloy on the copper surface to prevent the copper surface from being oxidized, and then provide a good soldering base for subsequent assembly. Do you know the difference between lead free HASL and HASL?
1. Lead-free HASL belongs to environmentally protection process and does not contain harmful substances "lead"; HASL is not an environmentally protection process and contains harmful substance "lead", which is harmful to human body for long-term use.
2. The lead content of lead free HASL shall not exceed 0.5, but the lead content of HASL shall reach 37.
3. From the surface of the tin, HASL is brighter and lead-free HASL is darker; The wettability of HASL is better than lead free HASL.
4. Lead will increase the activity of the tin solder wire during the soldering process. Compared with the lead free solder wire, the lead-containing solder wires is easier to use. Lead-free HASL has a higher melting point than HASL, and the solder joints will be much stronger.
Are you interested in learning more about multilayer pcb design tips? Contact us today to secure an expert consultation!
Additional reading:What is exactly halfway?
Revolutionizing Tech: IMSN PCBs - Are they worth the hype?
Ultimate Guide to PCBs in Auto Parts: Everything You Need to Know
What is the standard for PCB in automotive?
Hasl with Lead vs Lead Free: Which is safer for our environment and health?
Top 7 Multilayer PCB Design Tips Revealed
Top Automotive PCB Services: A Must-Read Guide!
5. The melting point of lead free HASL is about 218 degrees, the temperature of the tin stove needs to be controlled at 280-300 degrees, the temperature of wave soldering needs to be controlled at about 260 degrees, and the temperature of reflow soldering is about 260-270 degrees.
6. The melting point of lead free HASL is about 183 degrees, the temperature of the tin stove needs to be controlled at 245-260 degrees, the temperature of wave soldering needs to be controlled at about 250 degrees, and the temperature of reflow soldering is about 245-255 degrees.
HOYOGO is an international, professional and reliable PCB Manufacturer. We have a PCB design team with more than 12 years of work experience. The products we produce are rigid PCBs from 2 to 56 layers. At the same time, we can also provide FPC, HDI, and all other special PCB. With our rich experience and technical understanding, as well as our own production capacity and local centralized resources, we can provide you with one-stop service from small, medium to mass production.
Want more information on pcb surface finish comparison? Feel free to contact us.
What is the 4 code of a resistor?
5 Things You MUST Know About Omega Mart
Power Resistor vs Regular Resistor: What's the Difference?
Unlocking the Potential: Key Questions to Ask When Ordering Metal Film Resistor Application
What is a glass resistor?
Understanding LiFePO4 Batteries: A Powerful and Sustainable Energy Solution
Flexible Metal Conduit: Versatile Conduit Solutions
59
0
0
Previous: Which surface finish is best for PCB?
Related Articles
Comments
All Comments (0)