The first part of the work was to choose the most efficient glue. The laboratory has got five different glues: the H20E, the EG105, the E2101, the 10HTN and the 10HTS. Different tests have been made to allow making a good choice. After choosing the most efficient glue, the laboratory will have to begin the gluing of components on the Flex.
Two different tests were done to measure the electrical and mechanical resistance of the glues. The purpose of the first test that has been done with the glue alone is to measure the properties of the glue. The purpose of the second test that has been done with a component glued on a circuit is to show how is the comportment of the glue in real use.
The slides have been cured. The cure is different for each kind of glue. After the cure, two measures have been made: electrical resistance and mechanical resistance. The mechanical test was been made with a strip of scotch tape. This destructive test has been made for every third slide. The position of the scotch tape is shown in diagram 1 in dashed lines.
The H20E was cured at 120 degrees C for 15 minutes.
¯
The electrical resistance
The result of the test is in table 1.
|
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
average |
|
|
H20E (ohm) |
40.5 |
31.6 |
32.9 |
4.9 |
12.1 |
1.8 |
2.9 |
4.6 |
1.9 |
14.8 |
Table 1
The three first slides have been made with a wood spatula. For the next slides an another slide has been used to put the epoxy. Perhaps the slides made with the wood spatula are less even than the other. This could be the reason of the high values.
¯
The mechanical resistance
There was no epoxy of the strip of scotch tape after the test. The mechanical resistance of H20E is good.
The EG105 was cured at 120 degrees C for 60 minutes. But the UV cure was missing (no lamp!).
¯
The electrical resistance
The result of the test is in table 2.
|
1 |
2 |
3 |
average |
|
|
EG105 (ohm) |
0.416 |
0.219 |
0.225 |
0.287 |
Table 2
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The mechanical resistance
There were approximately 20% of the strip covered by the EG105. Two other mechanical tests have been made and each time it was the same result: 40% of the strip covered by the EG105.
After each mechanical test, the electrical resistance has been measured:
After the first: 0.5 ohm
After the second: 15.6 ohms
After the third: 205 ohms
The E2101 was cured at 175 degrees C for 15 minutes.
¯
The electrical resistance
The result of the test is in table 3.
|
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
average |
|
|
E2101 (ohm) |
0.551 |
0.528 |
0.484 |
0.857 |
0.623 |
0.634 |
0.613 |
Table 3
¯
The mechanical resistance
There was no epoxy of the strip of scotch tape after the test. The mechanical resistance of E2101 is good.
The 10HTS was cured at 120 degrees C for 60 minutes.
¯
The electrical resistance
The result of the test is in table 4.
|
1 |
2 |
3 |
4 |
5 |
6 |
average |
|
|
10HTS (ohm) |
199 |
147 |
89 |
525 |
430 |
762 |
359 |
Table 4
¯
The mechanical resistance
There was no epoxy of the strip of scotch tape after the test. The mechanical resistance of 10HTS is good.
The 10HTN was cured at 120 degrees C for 60 minutes. The 10HTN is very thick. It doesn’t stick on the slide. That’s why eight layers of scotch tape have been used to make the slides. Then the glue was put on all the slide. And the surplus was taken away with an another slide.
¯
The electrical resistance
The result of the test is in table 5.
|
1 |
2 |
3 |
average |
|
|
10HTN (ohm) |
18.2 |
18.4 |
18.2 |
18.3 |
Table 5
¯
The mechanical resistance
There was no epoxy of the strip of scotch tape after the test. The mechanical resistance of 10HTN is good.
The results of the first test are summarized in the table 6.
|
FIRST TEST |
|||||||||||
|
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
average |
||
|
H20E 2 components |
40.5 |
31.6 |
32.9 |
4.9 |
12.1 |
1.8 |
2.9 |
4.6 |
1.9 |
14.8 |
OK |
|
EG105 single |
.416 |
.219 |
.225 |
0.287 |
BAD ( no UV cure) |
||||||
|
E2101 2 components |
.551 |
.528 |
.484 |
.857 |
.623 |
.634 |
0.613 |
OK |
|||
|
10HTS single |
199 |
147 |
89 |
525 |
430 |
762 |
359 |
OK |
|||
|
10HTN single |
34000 |
10000 |
6600 |
18.2 |
18.4 |
18.2 |
18.3 |
OK |
|||
Table 6
The mechanical test of EG105 is bad but there was not done an UV precure. The relationship between the UV precure and the mechanical resistance can not be demonstrated because the laboratory has not an UV lamp.
The three first measures of the electric resistance, for the 10HTN, have been made with one layer of scotch tape. 10HTN is very thick and does not stick to the slide. That’s why the measures are huge. The three next measures have been made with a height of eight layers of scotch tape.
I.2 Tests of gluing a component
Some components have been glued on a circuit with H20E epoxy,E2101 epoxy and EG105. The circuit and the components have been cured. After the cure two tests have been made: an electrical test and a mechanical test. The first is to measure the electrical resistance of the components and the second is to measure the mechanical resistance with a force calibration meter.
Nine sets of pads have been used to glue the components.
Two components (39 ohms) have been glued with EG105 (single component). The UV cure has not been made. The cure was 120 degrees C for 60 minutes.
The result of the test is in table 7.
|
Resistance (ohm) |
Strength test (kg) |
|||
|
1 |
2 |
3 |
||
|
1st set of pads (EG105) |
27.7 |
13 |
||
Table 7
Three components (39 ohms) have been glued with H20E (2 components). They have been cured at 120 degrees C for 15 minutes.
The result of the test is in table 8.
|
Resistance (ohm) |
Strength test (kg) |
|||
|
1 |
2 |
3 |
||
|
2nd set of pads (H20E) |
39.06 |
38.7 |
39.27 |
1.16 and 1.25 |
Table 8
Three components (39 ohms) have been glued with H20E. They have been cured at 120 degrees C for 15 minutes
The result of the test is in table 9.
|
Resistance (ohm) |
Strength test (kg) |
|||
|
1 |
2 |
3 |
||
|
3rd set of pads (H20E) |
19.56 |
39.2 |
||
Table 9
Three components (39 ohms) have been glued with H20E (2 components). They have been cured at 120 degrees C for 15 minutes.
The result of the test is in table 10.
|
Resistance (ohm) |
Strength test (kg) |
|||
|
1 |
2 |
3 |
||
|
4th set of pads (H20E) |
38.94 |
19.52 |
38.97 |
2 |
Three components (39 ohms) have been glued with H20E (2 components). They have been cured at 120 degrees C for 15 minutes.
The result of the test is in table 11.
|
Resistance (ohm) |
Strength test (kg) |
|||
|
1 |
2 |
3 |
||
|
5th set of pads (H20E) |
39.2 |
13 |
19.6 |
|
Table 11
Three components (39 ohms) have been glued with 10HTN (single component with 10% of acetone by weight). They have been cured at 120 degrees C for 60 minutes.
The result of the test is in table 12.
|
Resistance (ohm) |
Strength test (kg) |
|||
|
1 |
2 |
3 |
||
|
6th set of pads (10HTN) |
55.25 |
69.1 |
49.36 |
|
Table 12
Three components (39 ohms) have been glued with 10HTN (single component with 10% of acetone by weight). They have been cured at 120 degrees C for 60 minutes.
The result of the test is in table 13.
|
Resistance (ohm) |
Strength test (kg) |
|||
|
1 |
2 |
3 |
||
|
7th set of pads (10HTN) |
62 |
63.2 |
54.3 |
|
Table 13
Three components (39 ohms) have been glued with E2101 (2 components). They have been cured at 175 degrees C for 15 minutes.
The result of the test is in table 14.
|
Resistance (ohm) |
Strength test (kg) |
|||
|
1 |
2 |
3 |
||
|
8th set of pads (E2101) |
40.24 |
39.33 |
39.31 |
|
Table 14
Three components (39 ohms) have been glued with E2101 (2 components). They have been cured at 175 degrees C for 15 minutes.
The result of the test is in table 15.
|
Resistance (ohm) |
Strength test (kg) |
|||
|
1 |
2 |
3 |
||
|
9th set of pads (E2101) |
40.89 |
39.97 |
41.52 |
1.1 |
Table 15
All the results of the second test are summarized in table 15
|
SECOND TEST |
||||
|
Resistance (ohm) |
Strength test (kg) |
|||
|
1 |
2 |
3 |
||
|
1st set of pads (EG105) |
27.7 |
13 |
||
|
2nd set of pads (H20E) |
39.06 |
38.7 |
39.27 |
1.16 and 1.25 |
|
3rd set of pads (H20E) |
19.56 |
39.2 |
||
|
4th set of pads (H20E) |
38.94 |
15.9 |
38.97 |
2 |
|
5th set of pads (H20E) |
39.2 |
13 |
19.6 |
|
|
6th set of pads (10HTN) |
55.25 |
69.1 |
49.36 |
|
|
7th set of pads (10HTN) |
62 |
63.2 |
54.3 |
|
|
8th set of pads (E2101) |
40.24 |
39.33 |
39.31 |
|
|
9th set of pads (E2101) |
40.89 |
39.97 |
41.52 |
1.1 |
Table 15
The conclusion and the choice of the glue have been made with the results of the first test. The purpose of the second test is to verify the comportment of the glue in real use.
There are two criterions for the choice of the glue: it must have a low electrical resistance and it must resist the mechanical test.
The study of the table 6 shows that there are four glues with a very low electrical resistance: the EG105, the H20E, the 10HTN and the E2101. The average of theirs resistance is 0.287 ohms (EG105), 14.8 ohms (H20E), 18.3 ohms (10HTN) and 0.613 ohms (E2101). The EG105 has not resisted the mechanical test and the 10HTN is not easy to use. That's why the choice should be the E2101 or the H20E. The second test shows that theirs comportment are good. The E2101 or the H20E should be the glue used to glue components on the Flex.
But more tests have to be done before a decision is made.