Workshop Practice

Question 1

Hazard

Answer 1

e.g. Hot Stove

Question 2

Exposure

Answer 2

e.g. Cooking on stove

Question 3

Consequence

Answer 3

e.g. Getting burned from stove

Question 4

Friable

Answer 4

Easily crumbled

Question 5

GHS

Answer 5

Globally Harmonized System of

Classification and Labelling of Chemicals

Question 6

Two types of clamp

Answer 6

Bar Clamp, G Clamp

Question 7

Brazing

Answer 7

Brazing is a metal-joining process in which two or more metal items are joined together by melting and flowing a filler metal into the joint, the filler metal having a lower melting point than the adjoining metal.

Question 8

Eutectic

Answer 8

A homogeneous mixture of substances that melts or solidifies at a single temperature that is lower than the melting point of any of the constituents.

Question 9

Common solder alloy in electronics:

Answer 9

63 Tin / 37 Lead (or 60 / 40), melts around 180-190 degrees.

Question 10

Common solder alloy for joining aluminium:

Answer 10

Tin / Zinc

Question 11

Common solder alloy for strength above room temperature:

Answer 11

Lead / Silver

Question 12

Common solder alloy for strength at high temperatures:

Answer 12

Cadmium / Silver

Question 13

Common solder alloy for aluminium and corrosion resistance:

Answer 13

Zinc / Aluminium

Question 14

Uncommon solder alloy in electronics:

Answer 14

Tin / Silver and Tin / Bismuth

Question 15

Flux (soldering)

Answer 15

Flux is a chemical cleaning agent used before and during the soldering process of electronic components onto circuit boards.

Question 16

Two types of Flux

Answer 16

Acid (for plumbing) and Rosin (for electronics)

Question 17

Three types of ‘Soft-Solder’ Flux

Answer 17

Water-Soluble Flux, No-Clean Flux, Rosin Fluxes

Question 18

Rosin Flux comes in three forms:

Answer 18

Non-Activated (R), Mildly-Activated (RMA) and Activated (RA) formulations

Question 19

RA and RMA fluxes contain rosin combined with:

Answer 19

An activating agent, typically an acid, which increases the wettability of metals to which it is applied by removing existing oxides.

Question 20

Three types of soldering:

Answer 20

Soft-Soldering, Silver-Soldering, Brazing

Question 21

Wetting

Answer 21

Wetting is a condition where the solder has become molten at its eutectic temperature with an adequate amount of flux.

Question 22

Wicking

Answer 22

When solder is drawn up into a braided wire between the strands by capillary action. Can be used as a technique for removing solder.

Question 23

Demarcation Temperature between Soldering and Brazing:

Answer 23

450 °C

Question 24

Wave Soldering

Answer 24

Wave soldering is a bulk soldering process used in the manufacture of printed circuit boards. The circuit board is passed over a pan of molten solder in which a pump produces an upwelling of solder that looks like a standing wave.

Question 25

PCB

Answer 25

Printed Circuit Board

Question 26

De-laminating

Answer 26

When too much heat is applied to a circuit board, melting the lamination layer and freeing the copper circuit.

Question 27

‘Easy’, ‘Medium’, or ‘Hard’ Solder refers to what?

Answer 27

Melting Point

Question 28

Dry Joint

Answer 28

A “dry joint” occurs when the cooling solder is moved, and often occurs because the joint moves when the soldering iron is removed from the joint.

Question 29

Cold Solder

Answer 29

This is when parts being joined do not exceed the solder’s liquidus temperature, resulting in a “cold solder” joint.