HIRANUMA APPLICATION DATAPLATING &ETCHING
SOLUTION

Data No.

Automatic Titrator

E9Oct. 7,2022

Determination of hydrogen peroxide andsulfuric acid in etching solution

1. Abstract
Sulfuric acid and hydrogen peroxide are main components of the etching solution which is used forcleaning the copper surface (soft etching) or half etching. The concentration of sulfuric acid and hydrogen
peroxide have to be properly controlled to maintain constant etching speed because hydrogen peroxide readily
decomposes by itself. This report introduces a measurement example as below.
1) Determination of sulfuric acid by neutralization titration with sodium hydroxide・・・(1)2) Determination of hydrogen peroxide by redox titration with potassium permanganate standardsolution.・・・ (2)H2SO4＋2NaOH→

Na2SO4

5H2O2 ＋ 2KMnO4 ＋ 3H2SO4→＋・・・(1)H2 O

K2SO4 ＋ 2MnSO4 ＋ 8H2O ＋ 5O2・・・(2)2. Configuration of instruments and reagents(1) Configuration
Main unit:

Hiranuma Automatic Titrator COM series

Option:Buret, buret head, and simple dispenser (peristaltic type), one by oneElectrodes:

Glass reference combination electrode GR-501BZ

Connect to IE-1.

Platinum electrode

Connect to IE-2.

PT-301(2) Reagents
Titrant:

0.1 mol/L sodium hydroxide standard solution (for sulfuric acid titration)
0.02 mol/L potassium permanganate standard solution (for hydrogenperoxide titration)

Additive solution:

10 mL of diluted sulfuric acid (1:9, v/v) (for pH adjustment)

3. Measurement procedure(1) Dispense 1 mL of sample into a 200 mL beaker with volumetric pipette.
(2) Add about 100 mL of DI water.
(3) Immerse electrodes and start titration with 0.1 mol/L sodium hydroxide standard solution.
(4) After that, 10 mL of diluted sulfuric acid is automatically dispensed. (Option: Simple dispenser)(5) Titrate with 0.02 mol/L potassium permanganate standard solution. (Option: Buret)4. Measurement conditions and results
Examples of titration conditions(1)Titration of sulfuric acidCndt No.
1MethodAutoBuret No.
1Amp No.
1
D. UnitpH
S-Timer
10C.P. mL
20T Timer
15
D.P. mL
0.5
End Sens
1000
Over mL
0.2
Max.Vol.
40

sec
mLsec
mLmLmL

Constant No.
SizeBlank
Molarity
FactorKL
Unit
Formula11.0000 mL
0.0000 mL
0.1000 mol/L
1.004049.0400.000g/L

Mode No.
Pre Int
Del KDel Sens
Int Time
Int Sens
Brt Speed
Pulse

20090232400.05

sec
mV
sec
mV

mL

(D-B)*K*F*M/SDigits4Auto In Pram.
None(2)Dispensing diluted sulfuric acid
Cndt No.
2Method
DispBuret No.
2S-Timer0 sec
Disp Vol.
10 mL(3)Titration of hydrogen peroxide
Cndt No.
3Method
AutoConstant No.
3Buret No.
3Size
1.0000 g
Amp No.
3Blank0.0000 mL
D. UnitmVMolarity
0.0200 mol/L
S-Timer
10 sec Factor
1.0050
C.P. mL
0.5 mL K
85.040T Timer
60 sec L
0.000
D.P. mL
0.5 mL Unit
g/L
End Sens
1000
FormulaOver mL
0.5 mL(D-B)*K*F*M/S
Max.Vol.
20 mL Digits
4Auto In Pram.
None

Mode No.
Pre Int
Del K
Del Sens
Int Time
Int Sens
Brt SpeedPulse

505033240
0.05

Measurement results
Number of
Measurement
123Size(mL)
1.00001.00001.0000Statistic calculation

Titrant
volume (mL)
27.15527.18227.197Sulfuric acid(g/L)
133.701133.834133.908

Titrant
volume (mL)
16.47916.492
16.523

Hydrogen peroxide(g/L)
28.167628.189828.2428

Avg.

133.81 g/L

Avg.

28.20 g/L

SD

0.10 g/L

SD

0.04

g/L

RSD

0.08 %

RSD

0.14%

Some measurement would not be possible depending on optional configuration of system.

secmV
sec
mV

mL

Measurement of sulfuric acid

Measurement of hydrogen peroxide

Examples of titration curves

5. NotePotassium permanganate standard solution is used for hydrogen peroxide titration in this report because
copper ion (Cu2+) coexists in the sample. If the sample does not contain copper ion (Cu2+) or iron ion (Fe3+) which
oxidize iodine ion, the determination of hydrogen peroxide with the iodometry method using sodium thiosulfate
titrant is also possible.
Keywords: Etching solution. Sulfuric acid, Neutralization titration, Hydrogen peroxide, Potassium permanganate

Some measurement would not be possible depending on optional configuration of system.