Procedure and results - Revision history

Abdehait: /* Burned vs. Unburned Hole */

2011-12-18T02:11:32Z

Burned vs. Unburned Hole

2011-12-15T17:13:57Z

Using a Squeegee

2011-12-15T17:13:18Z

Using a Squeegee

2011-12-13T19:20:06Z

Burned vs. Unburned Hole

2011-12-13T19:19:47Z

Burned vs. Unburned Hole

2011-12-13T19:17:16Z

Burned vs. Unburned Hole

2011-12-13T19:00:48Z

Copper Clad and Resistive Paste

2011-12-13T18:43:48Z

Copper Clad and Resistive Paste

2011-12-13T18:41:15Z

Copper Clad and Resistive Paste

2011-12-13T18:37:26Z

Copper Clad and Resistive Paste

← Older revision		Revision as of 02:11, 18 December 2011
Line 73:		Line 73:


−	== Burned vs. Unburned ~~Hole~~ ==	+	== Burned Hole vs. Unburned One ==

	A sample from a damaged card by discharge is tested. The thickness of resistive paste 3.5<math> \mu m </math> in average. The second image shows the area of damage on the rim of the hole where the nonconformity in paste and FR4 interference surface is expected, these areas accumulate a lot of charges. Cleaning the hole with distilled water removes the paste and any burn residues which affect the surface uniformity in the cleaned area. The last image does not show any change in the chemical structure in the burned area, but shows a lot of tiny cracks in that area are filled with air.		A sample from a damaged card by discharge is tested. The thickness of resistive paste 3.5<math> \mu m </math> in average. The second image shows the area of damage on the rim of the hole where the nonconformity in paste and FR4 interference surface is expected, these areas accumulate a lot of charges. Cleaning the hole with distilled water removes the paste and any burn residues which affect the surface uniformity in the cleaned area. The last image does not show any change in the chemical structure in the burned area, but shows a lot of tiny cracks in that area are filled with air.

@@ Line 15: / Line 15: @@
 ==Using a Squeegee==
- [[File:sqweegee_1.jpg|| 100px]]
+[[File:sqweegee_1.jpg|| 100px]]
 [[File:sqweegee_2.jpg|| 100px]]

@@ Line 15: / Line 15: @@
 ==Using a Squeegee==
-  insert a picture of the Aluminum squeegee by itslef and one with it mounted
+  [[File:sqweegee_1.jpg|| 100px]]
- on the milling machine with a PC board underneath it
+[[File:sqweegee_2.jpg|| 100px]]
 Applying the paste using a mechanically fixed squeegee. In this procedure, a very flat squeegee is manufactured to be fixed on a the desired height (in micrometer) over a horizontally moving table. The paste thickness is controlled an uncertainty of <math> \pm 25 \mu m \,\,\, (1 mil) </math>, the set up is designed to have an thickness of 10-15  <math> \mu m </math> in every single trip when the squeegee is scanning the card. The required thickness for the paste is 35 <math> \mu m </math> in average which will be achieved by Assembling two layers of paste.

@@ Line 77: / Line 77: @@
 A sample from a damaged card by discharge is tested. The thickness of resistive paste 3.5<math> \mu m </math> in average. The second image shows the area of damage on the rim of the hole where the nonconformity in paste and FR4 interference surface is expected, these areas accumulate a lot of charges. Cleaning the hole with distilled water removes the paste and any burn residues which affect the surface uniformity in the cleaned area. The last image does not show any change in the chemical structure in the burned area, but shows a lot of tiny cracks in that area are filled with air.
-[[File:.jpg || 100px]]
 [[File:burnedcard_5um_scale_1.jpg || 100px]]
 [[File:burnedhole_vs_hole.jpg || 100px]]
 [[File:burnedhole_5um_surface_001.jpg || 100px]]
 [[File:burnedhole_hole_ch_withbackground.jpg || 100px]]

@@ Line 75: / Line 75: @@
 == Burned vs. Unburned Hole ==
-A sample from a damaged card by discharge is tested which thickness of resistive paste 3.5<math> \mu m </math> in average. the second image shows the area of damage on the rim of the hole where the nonconformity in paste and FR4 interference surface is expected. Cleaning the hole with distilled water removes the paste and any burn residues which affect the surface uniformity in the cleaned area. The last image does not show any change in the chemical structure in the burned area, but shows a lot of tiny cracks in that area are filled with air.
+A sample from a damaged card by discharge is tested. The thickness of resistive paste 3.5<math> \mu m </math> in average. The second image shows the area of damage on the rim of the hole where the nonconformity in paste and FR4 interference surface is expected, these areas accumulate a lot of charges. Cleaning the hole with distilled water removes the paste and any burn residues which affect the surface uniformity in the cleaned area. The last image does not show any change in the chemical structure in the burned area, but shows a lot of tiny cracks in that area are filled with air.
 [[File:.jpg || 100px]]

@@ Line 64: / Line 64: @@
 The picture below shows the copper frame surrounds the resistive paste covered area.
 [[File:Cu_paste_combination_1.jpg || 100px]]
@@ Line 72: / Line 71: @@
 [[File:paste points.jpg || 100px]]
 [[File:paste.jpg || 100px]]

← Older revision		Revision as of 18:41, 13 December 2011
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	[[File:.jpg \|\| 100px]]		[[File:.jpg \|\| 100px]]
	[[File:Cu_paste_combination_1.jpg \|\| 100px]]		[[File:Cu_paste_combination_1.jpg \|\| 100px]]
		+
		+	A chemical analysis shows the structure of the resistive paste as shown below
		+
		+
		+	[[File:paste points.jpg \|\| 100px]]
		+	[[File:paste.jpg \|\| 100px]]

@@ Line 62: / Line 62: @@
 [[File:Cu_thickness_bothsides_1.jpg || 100px]]
-The
+The picture below shows the copper strip surrounds the resistive paste covered area.
 [[File:.jpg || 100px]]
 [[File:Cu_paste_combination_1.jpg || 100px]]