Copper is an excellent electrical conductor widely used in...

Copper is an excellent electrical conductor widely used in making electric circuits. In producing a printed circuit board for the electronics industry, a layer of copper is laminated on a plastic board. A circuit pattern is then printed on the board using a chemically resistant polymer. The board is then exposed to a chemical bath that reacts with the exposed copper, leaving the desired copper circuit, which has been protected by the overlaying polymer. Finally, a solvent removes

Key Concepts

Solvent Removal

Solvent removal refers to the use of a solvent to eliminate the resist material after the etching process has completed. This step cleans up the board, revealing the final design of the copper patterns necessary for the board's functioning.

Resist Patterning

Resist patterning is a technique in which a chemically resistant material, often a polymer, is applied and then patterned on the board to protect specific areas during subsequent processes. This masking step is crucial to define the circuit pathways by safeguarding the desired copper regions.

Chemical Etching

Chemical etching is the process of selectively removing material by exposing it to a chemical solution that reacts with open areas. In printed circuit board manufacturing, it is used to remove unprotected copper, leaving behind the circuit pattern defined by the resist mask.

Printed Circuit Board Fabrication

This is the overall process of creating boards on which electronic components are mounted and connected. It involves multiple steps including material preparation, patterning, etching, and finishing to form functional circuits that support electronic device operation.

Electrical Conductivity

This concept refers to the ability of a material to allow the flow of electric current with minimal resistance. Copper is often used in electronic applications due to its high electrical conductivity, making it essential for circuits and various electronic components.

Lamination Process

Lamination involves bonding a thin layer of conductive material, such as copper, onto an insulating substrate, typically a plastic board. This process provides a stable base for further fabrication steps and is fundamental in constructing multilayer circuit boards.

Transcript

00:01 We will be considering copper and its use in circuit boards.

00:06 As you know, copper is an excellent electrical conductor.

00:10 It's, of course, widely used in making electrical circuits.

00:14 To produce a printed circuit board, a layer of copper is laminated on a plastic board.

00:22 Circuits then printed on the board using a chemically resistant polymer.

00:27 Then the board's exposed to a chemical bath that reacts with the exposed copper.

00:34 Leaving the circuit which is been protected by the overlaying polymer.

00:41 Then a solvent wash removes the polymer so only the circuit part of the copper is left exposed.

00:52 One reaction used to remove the exposed copper from the circuit board is this.

01:01 The solid copper reacts with cu and h34 cl2 and need room for my coefficient.

01:21 There and the product is to cu and h3 4 cl i don't know if i'm gonna have room for my aq there we go a plant needs to produce 5 ,000 boards the boards are 2 inches by 3 inches and the thickness of the copper is 0 .65 millimeters in the wash 85 percent of the copper is removed.

02:43 If the reaction gives a 97 % yield, find the mass of the cun -nh -3 -4 -c -l2 product and the reactant and this reactant.

03:18 Those two reactants.

03:22 Okay, on this page, let's go ahead and get our volume from whence we can get our mass and i did this by converting my inches and i was given two sig figs and there are 2 .5 four centimeters per inch which gave me zero or excuse me 5 .08 centimeters i did the same thing with three inches and for this i got 7 .62 centimeters and to get our volume which is simply lwh i took 5 .08 centimeters times 7 .62 centimeters and i multiplied that by this number converted to centimeters which is 065 centimeters.

05:02 I feel like i didn't do this right away yes i did so that was 2 .516 centimeters cubed.

05:17 Let me check here.

05:18 I had to have been good density.

05:20 Yes, 8 .96.

05:37 And to get the mass, we took 2 .516 cubic centimeters and multiplied that by 8 .96 grams per cubic centimeter for 22 .5 445 grams of copper.

06:23 Very good.

06:24 I'm going to go to the next page now.

06:43 I'm looking where i got a particular number here.

06:45 I feel like i'm losing my mind.

06:48 So i had 22 .5445 grams of copper...