Do you know the difference between IPC Level 2 and IPC Level 3? What is the impact of the two on PCB products? In this article, 2PCB Technology will tell you what the differences are and what acceptance criteria each includes.
IPC Level 2 products are dedicated service electronic products, including communication equipment, complex industrial and commercial equipment, and high-performance, long-life measuring instruments. The IPC Level 2 standard clarifies that such products should not malfunction under normal use conditions.
IPC level three products, that is, high-performance electronic products, include highly reliable, long-life military and civilian equipment that can continue to operate. This type of product is absolutely not allowed to cause interruptions during use. At the same time, reliable start-up and operation of the equipment must be ensured in harsh environments. For example, medical life-saving equipment and all military equipment systems.
| Compare parameter items | IPC Level 2 | IPC Level 3 |
| Average copper thickness | 20um | 25pm |
| Copper layer voids | There should be no more than 1 void in the hole The number of holes containing voids does not exceed 5% The length of the void does not exceed 5% of the hole length The circularity of the cavity is not greater than 90 degrees |
No voids in the hole |
| Plating voids in finished coating | There should be no more than 3 voids in the hole The number of holes containing voids does not exceed 5% The length of the void does not exceed 5% of the hole length The circularity of the cavity is not greater than 90 degrees |
There should be no more than 1 void in the hole The number of holes containing voids does not exceed 5% The length of the void does not exceed 5% of the hole length The circular length of the cavity is not greater than 90 degrees |
| General rules for surface coatings | The exposed copper/plated overlap area is not larger than 1.25mm | The exposed copper/plated layer intersection area is not larger than 0.8mm |
| Etched logo | As long as the characters are clear, ink can accumulate outside the character lines The outline of the component orientation symbol may be partially detached as long as the required orientation remains clear. The marking ink on the component hole pad must not penetrate into the component mounting hole or cause the ring width to be lower than the minimum ring width |
As long as the characters are clear, ink can build up outside the character lines |
| Straw type gap | Straw-like voids appear along the side edges of the conductive pattern. This results in a reduction in the conductor spacing that does not fall below the minimum specified requirements, and the straw-like void does not extend to the entire edge of the conductive pattern | No straw-style gap |
| Wire spacing | Any combination of defects such as rough copper burrs on the edges of wires causes the reduction in wire spacing in isolated areas to be no more than 30% of the minimum wire spacing | Any combination of defects such as rough edges and thorns on wires causes a reduction in wire spacing in isolated areas by no more than 20% of the minimum wire spacing |
| Outer ring width of support hole | The breakage is not greater than 90 degrees and meets the minimum lateral spacing requirements. In the connection area between the pad and the wire, the reduction in wire width is not greater than 20% of the nominal minimum wire width in the engineering drawing or production master, and the break is allowed to be 90 degrees. The wire connection should be no less than 0.05mm or the minimum line width, whichever is smaller |
The hole is not located in the center of the pad, but the ring width is not less than 0.05mm (0.0020in) Ring width in isolated areas due to defects such as pits, dents/nicks, pinholes or angled holes Minimum outer ring width allowed to be reduced by 20% |
| Ring width of unsupported hole | There is an unbroken hole ring width | The ring width in any direction is not less than 0.15mm (0.00591in). Due to the existence of defects such as pitting, pits, notches, pinholes or oblique holes in the inner hole ring in the oblique area, the minimum outer ring width is allowed to be reduced by 20% |
| Negative etchback | Negative etching is less than 0.025mm | Negative etching is less than 0.013mm |
| Inner ring width | The broken ring is no more than 90 degrees | The minimum ring width is not less than 0.025mm |
| Wicking | Wicking effect is not greater than 0.10mm (0.0040in) | The wicking effect is not greater than 0.08mm |
| Wicking effect of isolation holes | Wicking effect is not greater than 0.10mm (0.0040in) | The wicking effect is not greater than 0.08mm |
| Coverage | There are weldable eyelets within at least 270 degrees of the circumference | The minimum weldable hole ring width on the entire circumference is 0.13mm (0.00512in) |
| Coincidence of clearance holes in covering layer and reinforcing plate | There is at least one weldable eyelet ring within 270 degrees of the circumference | The minimum weldable hole ring width on the entire circumference is 0.13mm For non-support holes, the ring width of the weldable hole should not be less than 0.25mm |
| Connection of metal core to plated hole wall | The separation at the interconnection should not be greater than 20% of the thickness of the metal core. If a copper-clad metal core is used, there should not be any separation in the copper interconnection | No separation at the interconnection |
When you receive an IPC Level 2 board and are unsure of the acceptance and judgment standards, you can compare them one by one based on the parameters in the table above to quickly determine whether the circuit board truly meets the IPC Level 2 standard. It is recommended to collect the above table so that it can be used in the future!