In the PCB design process, the PCB layout and material specifications may include the base material of the circuit board, the laminate and the core layer stack. These choices are good design-to-manufacture (DFM) utilization common to all. However, many choices of PCB surface finish are often not adequately considered. Instead, the software default values ​​are used. However, surface finish is a very important consideration. It affects the reliability of PCB assembly and circuit board by protecting copper traces and strengthening solder connections. In addition, several types of PCB surface treatments are listed below.

Hot air soldering grade (HASL)

Lead-free HASL

Organic Solderability Preservative (OSP)

Immersion Silver (Au)

Immersion Tin (Sn)

Electroless nickel plating (ENIG)

Electroless nickel and chemical palladium immersion gold (ENEPIG)

Electrolytic solderable gold

Electrolytic hard gold

Making the right choice for your design requires understanding the differences between the available types.

1. Lead-free solder-adhere to the Restriction of Hazardous Substances (ROHS) regulations.

2. Processing sensitivity-easy to be contaminated or damaged due to processing.

3. Wire bonding-can form a good wire bonding connection.

4. Small pitch-can be used for small pitch components, such as ball grid array (BGA).

5. Contact usage-use a contact as a contact.

6. Shelf life-with a good shelf life, it can be stored for more than six months.

7. Extra cost-usually increase PCB manufacturing cost.

Now, with a set of comparison attributes, we can better solve the problem of which type of PCB finish to use.

Comparison of PCB surface treatment types

The above attributes are very important and can be used to help you choose the best type of PCB surface treatment. However, you should consult the contract manufacturer (CM) to understand the specific cost variance and other factors that may affect your decision, such as additional turnaround time.