HASL VS ENIG – what are advantages and disadvantages?
So far, we have discussed what these two types of finishes are. In a way, we can say the hot air solder leveling (HASL) has some specific advantages over the electroless nickel immersion gold (ENIG) and vice versa. However, here in this section, we would specify each type of surface finish, the advantages and the disadvantages. It is important to note that no surface finish has a gift without a penalty, and therefore, the selection of any surface finish is based on a particular application.
Advantages of HASL
It is well known, hot air solder uniform, HASL process type is one of the major surfaces of the printed circuit board used in the PCB industry. Some of the advantages attached to its use include;
• Ability to expose the printed circuit board to a temperature which can be up to 265°c. Exposing the printed circuit board to this
The extent of weather allows for detecting any possible problem before the attachment of any component to the board.
• The hot air solder leveling is uncomplicated to run.
• It is a type of surface finish that is pocket-friendly; that is, the cost is low.
• The hot air solder leveling is well known for its ability to offer a long storage life.
• It is generally available. It can be an excellent advantage over other types of surface finish.
• The hot air solder leveling disallows for the oxidation of copper.
• A perfect wetting throughout the process of joining or soldering components.
• This type of surface finish can be inspected visually.
Disadvantages of HASL
From one perspective, each advantage is always in a relationship with another disadvantage. There are strengths and weak points attached to every type of surface finish. Some of the weakness identified with the hot air solder leveling includes:
• This type of surface finish is not suitable for the Surface-mount technology (SMT) due to the irregular surfaces involved with
The hot air solder leveling.
• It is not eligible for fine pitch, going in hand with the first point. Horizontal levelers are required to enhance flatness.
• Concerning boards that are additionally thin or thick, HASL has some specific restrictions, making it unsuitable for fabrication.
• Printed circuit boards may face some drawbacks due to high heat exposure in their processes.
• Inability to withstand tight tolerance on the plated holes.
• The hot air solder leveling is not appropriate for line binding.
• The plated through holes might get cracked due to high temperatures using this surface finish.
Advantages of ENIG
•, Unlike the hot air solder leveling, the electroless nickel immersion gold offers a flat surface
• It is a type of surface finish suitable for plated through holes.
• More like the hot air solder leveling, it provides good storage life
• It has no lead
• This type of surface finish is suitable for use as bottom metal for cob wiring.
• ENIG has an excellent electrical conductivity ability
• The electroless nickel immersion gold is recognized for its capability to prevent oxidation.s
Disadvantages of ENIG
• One major challenge is that it is expensive
• Unlike the hot air solder leveling, the ENIG is not re-workable
• The electroless nickel immersion gold is associated with signal loss
• Unlike the HASL, ENIG has a more complicated process.
• ENIG is prone to the black pad, due to its low wielding strength