2.Adhesive Application
1. Thin or insufficient adhesive can cause the chips to loosen or become disconnected during flow soldering.
The amount of adhesive must be more than dimension c, shown in the drawing at right, to obtain
the correct bonding strength.
The chip's electrode thickness and land thickness must also be taken into consideration.
a=20
～
70μm
b=30
～
35μm
c=50
～
105μm
2. Low viscosity adhesive can cause chips to slip after mounting. The adhesive must have a viscosity of
5000Pa • s (500ps) min. (at 25
℃
)
3. Adhesive Coverage
Part Number
Adhesive Coverage*
GQM18
0.05mg min.
GQM21
0.1mg min.
*Nominal Value
4. Do not apply flow soldering to GQM22 Series.
3.Adhesive Curing
1. Insufficient curing of the adhesive can cause chips to disconnect during flow soldering and causes
deterioration in the insulation resistance between the outer electrodes due to moisture absorption.
Control curing temperature and time in order to prevent insufficient hardening.
4.Flux Application
1. An excessive amount of flux generates a large quantity of flux gas, which can cause a deterioration
of Solderability.
So apply flux thinly and evenly throughout. (A foaming system is generally used for flow soldering).
2. Flux containing too a high percentage of halide may cause corrosion of the outer electrodes unless
there is sufficient cleaning. Use flux with a halide content of 0.2% max.
3. Do not use strong acidic flux.
4. Do not use water-soluble flux.
(*Water-soluble flux can be defined as non ro
ｓ
in type flux
including wash-type flux and non-wash-type flux.)
5.Flow Soldering
Set temperature and time to ensure that leaching of the
outer electrode does not exceed 25% of the chip end
area as a single chip (full length of the edge A-B-C-D
shown right) and 25% of the length A-B shown below as
mounted on substrate.
Notice
Chip Capacitor
Board
Adhesive
Land
a
b
c
A
B
D
C
Outer Electrode
［
As a Single Chip
］
［
As Mounted on Substrate
］
A
B
JEMCNC-0012L
23
