Spec No. JEFL243C-9115B-01 P7/10
MURATA MFG.CO., LTD
Reference Only
14.5 Attention regarding P.C.B. bending
The following shall be considered when designing and laying out P.C.B.'s.
(1) P.C.B. shall be designed so that products are not subject to the mechanical stress due to
warping the board.
［Products direction］
Products shall be location the sideways
Direction (Length : a<b) to the mechanical
Stress.
(2) Components location on P.C.B. separation.
It is effective to implement the following measures, to reduce stress in separating the board.
It is best to implement all of the following three measures; however, implement as many measures as possible
to reduce stress.
Contents of Measures Stress Level
(1) Turn the mounting direction of the component parallel to the board separation surface. A > D *1
(2) Add slits in the board separation part. A > B
(3) Keep the mounting position of the component away from the board separation surface. A > C
*1 A > D is valid when stress is added vertically to the perforation as with Hand Separation.
If a Cutting Disc is used, stress will be diagonal to the PCB, therefore A > D is invalid.
(3)
Mounting Components Near Screw Holes
When a component is mounted near a screw hole, it may be affected by the board deflection that occurs during
the tightening of the screw. Mount the component in a position as far away from the screw holes as possible.
14.6 Attention Regarding P.C.B. Design
< The Arrangement of Products >
P.C.B. shall be designed so that products are
far from the portion of perforation.
The portion of perforation shall be designed
as narrow as possible, and shall be designed
so as not to be applied the stress in the
case of P.C.B. separation.
Products shall not be arranged on the line
of a series of holes when there are big
holes in P.C.B.
(Because the stress concentrate on the
line of holes.)
〈
Poor example
〉
〈
Good example
〉
b
a
○
×
×
○
P.C.B.
Portion of
Perforation
Portion of
Perforation
Product
Product
P.C.B.
Hole
○
×
Screw Hole
Recommended
Perforation
Slit
B
C
D
