A complete list of other Terms related to Circuit Board PCB (III)

1, Guide Pin

When multiple contacts complex Yin and Yang Connectors (Connectors), to do the correct alignment of the joint, can first use an intermediary Guide Pin as an aid, the guide pin is called guide pin.

2. Halon

Allied Chemical Corp. is a trade name for "chlorofluorocarbons." Is mainly used as fire extinguishing agent. There are three common kinds of Halon-1211(CF2ClBr),Halon 1301(CF3Br), and Halon-2402 (C2F4Br2). The Montreal Treaty agreed in 1992 that Halon should be cut by 50 per cent by 1995 and completely banned by the year 2000.

3. harness cable assembly

Refers to the electrical components of each unit, in electrical Interconnecting (Interconnecting) a number of wires, synonymous with Cable.

4. Heat Dissipation

When the computer operation Speed (such as Switching Speed) more and more fast, need to use a kind of high power IC(often up to 6W or 8W above), so will produce a lot of heat, must try to be dispersed or diluted or offset, in order to maintain the good operation and performance of the machine. Available methods such as air convection cooling, add heat sink, or set up a variety of refrigerant pipelines, are called heat dissipation.

5, Heat Distortion Point(Temp.)

According to ASTM D468 standard test plate, under the fixed external pressure (66 or 264 PSI) and gradually heating conditions, forcing the test plate to produce more than 10mil bending deformation, the minimum temperature, called the "thermal deformation point".

6. Heat Sealing

A sealing method for heating and pressurizing the joint of a heat-sealed plastic film to make it fuse together.

7, Heat Transfer Paste

Silicone Grease refers to a silicone grease or other similar carrier with good high-temperature stability, in which a heat transfer paste is made by adding a substance capable of heat transfer (e.g., beryllium oxide powder or aluminum oxide powder). This product can be applied between the IC body and its external Heat Sink, or between the shell, to improve its heat transfer efficiency. Use should not be too much, so as not to bring pollution later.

8. Hertz(Hz)

Refers to the frequency of the radiation wave, that is, one Cycle per second (1 Hz = 1 Cycle/sec).

9. High Efficiency Particulate Air Fillter(HEPA)

The micro-fiber, which is easy to bend, is tightly folded into the "Accordion" type filter material with a large area, and the low pressure pump is installed to generate comfortable and slow air flow through the filter material and filter out all the dust particles. This air filtration system with filtration efficiency up to 99.99% is called HEPA. Note that A also has data written as "Attenuator".

10. Hydrolysis

Simply said is the addition of water caused by the decomposition of substances, is a chemical reaction. Such as salts, acids or organic matter added to the water, the generation of a variety of ions or ion groups.

11. Hydrophilic

Polar substances are soluble in water and are called hydrophilic. The person who does not have Nonpolar and does not dissolve in water and is Hydrophobic is called "hydrophobic".

12. Hypersorption

Refers to the vast surface area of activated carbon, may be less volatile components in the surrounding gas adsorption, but the volatile component is not easy to adsorption, this adsorption is called Hypersorption.

13. IPC American printed circuit board Association

The Instiute of Printed Circuits was The Instiute of Printed Circuits, founded in 1957 with only six members, as a non-profit civil academic society. Now it has become an international organization, and the total number of group members in the industry is close to 1500. In December 1977, it was renamed "The Institutefor Interconnecting and Packaging Electronic Circuits", but the acronym IPC remained unchanged. But its actual scope has been expanded from the early simple "circuit board manufacturing" to the current board, parts, assembly and other engineering technology and specification research. Its Logo has also been changed several times. IPC is one of the world's most accomplished academic societies in the circuit board industry. It has led a variety of professional research and developed a variety of important standards, which are widely relied upon by both upstream and downstream industry.

14, Internal Stress 

When the Lattice Structure of a metal is deformed under the influence of external forces within the Elastic Range, the deformation from the original dotted line to the black dot and solid line on the left of the figure is called "elastic deformation". However, if the external force is large and exceeds the elastic range, it will cause another Plasic Deformation, also called "Slip", as shown in the figure on the right, which can not be restored even after the external force is removed. The force by which a deformed metal atom wants to return to its original position is called the "Elastic Stress", also known as the "Residual Stress". In general, the cause of internal stress in electroplating, in addition to the "external force", there are impurities such as oxide, hydrate, sulfur, carbon, hydrogen or metal impurities will also cause internal stress. However, most of the internal stress can be eliminated in a short time after plating, if it can be treated at a high temperature below 200℃ for 2 ~ 4 hours.

15. JEDEC Joint Electronic Component Engineering Committee

Joint Electronic Device Engineering Council, an organization of EIA(Electronic Industries Association), We are one of the three most authoritative organizations in the field of packaging and assembly of SMD surface adhesive components. The other two associations are IEC International Electrotechnical Commission and IPC.

16, the Job Shop is a professional factory

For example, a Job Shop is a specialized factory that specializes in the production of circuit boards, treats circuit boards as commodities, and takes circuit board manufacturing as its main business. It is different from the Captive shop affiliated to a large enterprise.

17, Joule

The mechanical definition is the work done by moving 1 meter with a force of 1 Newton (N? m), in electrical engineering refers to the "electrical energy" required to move a coulomb of "charge" between two points when the potential difference is 1 volt, called 1" joule ". What is commonly referred to as 1 kilowatt? Hours) is equal to 3.6 x 106 joules.

18, Junction surface

The word is used in many ways. There are about three ways of saying it: * Close contact between two different metals or non-metals. A connection between two or more conductors or transmission lines. * Refers to the surface bonding between the P-type and N-type of its semiconductor material in a transistor or diode.

19, Karat, open

This word has two meanings, translated as "carat" is used as a unit of weight for diamonds, that is, 1 carat = 0.2 grams. Also translated as "Kai", or simply referred to as K, refers to the purity of the gold unit; It is customary to divide pure gold into 24 equal parts as a term for "gold purity". For example, 18 karat gold means that 18 of them are pure gold, and the remaining 6 are alloys composed of silver or copper. 24 karat gold is 100% pure gold. Kauri-Butanol Value (K.B for short). This is a test of Solvency for organic liquids or solvents. PCB industry will use this term in welding, such as various cleaning fluid of flux residue, its equal solubility can be compared by this value. Kauri is the name of a natural Gum that is soluble in butanol but not in other hydrocarbon solvents. The KB value is obtained if butanol dissolved in corritol is used as a standard test solution and other unknown solvents are added in small amounts until turbidity occurs (due to the insolubility of corritol in other solvents). General solvents have a fixed KB value, such as tea 30, toluene 105, etc.