In general, delamination and blistering occurs as a result of an inherent weakness of the material or process. Delamination or blis- tering between nonfunctional areas and functional areas may be acceptable provided that the imperfections are nonconductive
and that other criteria are met.
Blistering – Delamination in the form of a localized swelling
and separation between any of the layers of a lamination base material, or between base material and conductive foil or pro-
tective coating.
Delamination – A separation between plies within a base
material, between a base material and a conductive foil or any other planar separation with a printed board.
Target – Class 1,2,3 • No blistering or delamination.
Acceptable – Class 1 • The blister or delamination spans more than 25 of the dis-
tance between conductors, but does not reduce the space between internal conductor patterns below the minimum
conductor spacing.
Acceptable – Class 2,3 • The blister or delamination does not span more than 25 of
the distance between adjacent conductive patterns.
1 2
Figure 10-11
1. Blistering 2. Delamination
Figure 10-12
Figure 10-13
10.2.2 Laminate Conditions – Blistering and Delamination
10-7 IPC-A-610F
July 2014
Defect – Class 1,2,3 • Blisterdelamination exceeds 25 of the distance between
plated-through holes or internal conductors. • Blisteringdelamination reduce the space between conduc-
tive patterns below the minimum electrical clearance.
Note: Blisters or delamination areas may increase during assembly or operation. Separate criteria may need to be
established.
Figure 10-14
1
2 2
Figure 10-15
Figure 10-16
Figure 10-17
10.2.2 Laminate Conditions – Blistering and Delamination cont.
10-8 IPC-A-610F
July 2014
Weave Texture – A surface condition of base material in
which a weave pattern of glass cloth is apparent although the unbroken fibers are completely covered with resin.
Acceptable – Class 1,2,3 • Weave texture is an acceptable condition in all classes
but is confused with weave exposure because of similar appearance.
Note: Microsection may be used as a reference for this condition.
Weave Exposure – A surface condition of base material in
which the unbroken fibers of woven glass cloth are not com- pletely covered by resin.
Target – Class 1,2,3 • No weave exposure.
Acceptable – Class 1,2,3 • Weave exposure does not reduce the spacing between
conductive patterns below specification minimums. Acceptable – Class 1
Defect – Class 2,3 • Surface damage that cuts into laminate fibers.
Defect – Class 1,2,3 • Weave exposure reduces the spacing between conductive
patterns to less than the minimum electrical clearance.
Figure 10-18
Figure 10-19
IPC-610-173
Figure 10-20
Figure 10-21
10.2.3 Laminate Conditions – Weave TextureWeave Exposure
10-9 IPC-A-610F
July 2014
Haloing – A condition existing in the base material in the form of a light area around holes or other machined areas on or below
the surface of the base material. Mechanically induced fracturing or delamination on or below the surface of the base material; a light area around the holes, other machined areas or both are usually indications of haloing.
Target – Class 1,2,3 • No haloing
Acceptable – Class 1,2,3 • The distance between the haloing penetration and the near-
est conductive feature is not less than the minimum lateral conductor spacing, or 0.1 mm [µin] whichever is less.
Figure 10-22
Figure 10-23
Figure 10-24
10.2.4 Laminate Conditions – Haloing
9-10 IPC-A-610F
July 2014
Defect – Class 1,2,3 • The distance of the haloing penetration and the nearest con-
ductive feature is less than the minimum lateral conductor spacing, or less than 0.1 mm [4 µin].
Figure 10-25
Figure 10-26
Figure 10-27
10.2.4 Laminate Conditions – Haloing cont.
10-11 IPC-A-610F
July 2014
Delamination – A separation between plies within a base material, between a base material and a conductive foil, or any other
planar separation within a printed board. 10.2.1 has additional crazing criteria.
Target – Class 1,2,3 • No edge delamination.
• No nicks, crazing or damage on smooth board edges. Acceptable – Class 1,2,3
• Nicks do not exceed 50 of the distance from the printed board edge to the nearest conductor or 2.5 mm [0.1 in],
whichever is less. • Delamination or crazing at the edge of the printed board
does not reduce spacing to the nearest conductor to less than the specified minimum distance or less than 2.5 mm
[0.1 in] if not specified. • Board edges are rough but not frayed.
10.2.5 Laminate Conditions – Edge Delamination, Nicks and Crazing
10-12 IPC-A-610F
July 2014
Defect – Class 1,2,3 • Nicks exceed 50 of the distance from the printed board
edge to the nearest conductor or 2.5 mm [0.1 in], whichever is less, see Figure 10-28.
• Delamination or crazing at the edge of the printed board reduces spacing to the nearest conductor to less than the
specified minimum distance or less than 2.5 mm [0.1 in] if not specified.
• Cracks in the laminate, see Figure 10-29 arrow.
Figure 10-28
Figure 10-29
10.2.5 Laminate Conditions – Edge Delamination, Nicks and Crazing cont.
10-13 IPC-A-610F
July 2014
Defect – Class 1,2,3 • Burns that physically damage surface or the assembly.
Figure 10-30
Figure 10-31
Figure 10-32
10.2.6 Laminate Conditions – Burns
10-14 IPC-A-610F
July 2014
Figure 10-33 is an example of bow.
Acceptable – Class 1,2,3 • Bow and twist does not cause damage during post solder
assembly operations or end use. Consider ‘‘Form, Fit and Function’’ and product reliability.
Defect – Class 1,2,3 • Bow and twists causes damage during post solder assem-
bly operations or end use or affects form, fit or function.
Note: Bow and twist after solder should not exceed 1.5 for through-hole and 0.75 for surface mount printed board
applications. IPC-TM-650 has Test Method 2.4.22 but this is specifically for bare boards. Component size and placement
on assemblies often precludes use of that test method for populated assemblies. It may be necessary to confirm through
testing that bow and twist has not created stress that will result in solder connection fracture, component damage or
will otherwise cause damage during post solder assembly operations or use.
Figure 10-33
2 1
1 2
3
A B
C
Figure 10-34
1. Bow 2. Points A, B and C are touching base
