Caution
!
■Mounting
1. Selection of Conductive Adhesive, Mounting Process, and Bonding Strength
1.The acuired bonding strength may change greatly depending on the conductive adhesive to be used.
ꢀ Be sure to confirming the desired performance can be acquired in the assumed monting process
ꢀ with the conductive adhesive to be used.
2.Maintenance of the Mounting (pick and place) Machine
1. Make sure that the following excessive forces are not applied to the capacitors.
1-1. In mounting the capacitors on the printed circuit board, any bending force against them shall be kept
to a minimum to prevent them from any damage or cracking. Please take into account the following precautions
and recommendations for use in your process.
(1) Adjust the lowest position of the pickup nozzle so as not to bend the printed circuit board.
(2) Adjust the nozzle pressure within a static load of 1N to 3N during mounting.
Suction Nozzle
ꢀ [Incorrect]
Deflection
Board
Board Guide
ꢀ [Correct]
Support Pin
2.Dirt particles and dust accumulated between the suction nozzle and the cylinder inner wall prevent
the nozzle from moving smoothly. This imposes greater force upon the chip during mounting,
causing cracked chips. Also, the locating claw, when worn out, imposes uneven forces on the chip
when positioning, causing cracked chips. The suction nozzle and the locating claw must be maintained,
checked and replaced periodically.
3.Moisture proof
1.To prevent the silver electrode migration, keep parts under low moisture condition with resin coating and the equivalent.
4.Coating
1. A crack may be caused in the capacitor due to the stress of the thermal contraction of the resin during curing process.
The stress is affected by the amount of resin and curing contraction. Select a resin with low curing contraction.
The difference in the thermal expansion coefficient between a coating resin or a molding resin and the capacitor
may cause the destruction and deterioration of the capacitor such as a crack or peeling, and lead to the deterioration
of insulation resistance or dielectric breakdown.
Select a resin for which the thermal expansion coefficient is as close to that of the capacitor as possible.
A silicone resin can be used as an under-coating to buffer against the stress.
2. Select a resin that is less hygroscopic.
Using hygroscopic resins under high humidity conditions may cause the deterioration of the insulation resistance
of a capacitor. An epoxy resin can be used as a less hygroscopic resin.
3．The halogen system substance and organic acid are included in coating material, and a chip corrodes
ꢀꢀby the kind of Coating material. Do not use strong acid type.
JEMCGC-04887
13
MURATA [ muRata ]
