LIANG DAR

Technology Related

LIANG DAR

Technology Related

Ans

1、FR4 Tg 130~140
2、FR5 Mid Tg150~
3、FR5 High Tg 170~200
4、BT Tg 200~
5、Metal substrate, aluminum/copper, with a heat dissipation medium layer containing fiberglass cloth or pure resin film.
6、High-frequency materials
7、PTFE (Polytetrafluoroethylene) materials

Ans

1、Organic Solderability Preservatives (OSP)
2、Immersion Nickel / Gold (ENIG) 
3、Immersion nickel / Palladium / Gold (ENEPIG) 
4、Immersion Tin 
5、Immersion Silver
6、HASL
7、Lead-Free HASL
8、Soft Gold
9、Hard Gold

 
 
 
 

Ans

While the term "solder mask" is more commonly used, "solder resist" is actually the more appropriate term. A solder mask is a durable resin layer that covers the areas of a PCB where soldering isn't required to prevent the solder from sticking to those areas. In addition to its solder-resistant properties, the solder mask also provides protection and insulation for the conductors it covers. The industry often refers to the solder mask as "green paint". However, a solder mask is not necessarily always green. It comes in a variety of colors, such as black, white, blue, red and yellow, depending on the functional needs. Despite the variety, green remains the most popular choice. (Terminology Manual for PCB & Carrier by Rongsheng Bai)

Ans

Liang Dar provides a wide range of colors. The most popular one is green, followed by white and black. Some customers also choose grey, red and blue for mass production. Should you have any special requirements for colors, do not hesitate to contact our sales staff.

Ans

Liang Dar provides CNC milling and punching methods which are widely used in the industry. CNC milling is relatively slower and not as precise. This method can lead to rounded corners and may not be able to create perfect right angles. However, CNC milling offers a smooth and flat cutting surface without chipping. The punching method is relatively more efficient and can easily produce various shapes and cutouts. This method offers high precision as well. However, the surface finish is not as smooth or flat and chipping can be common. With years of experience manufacturing PCBs using the punching method, Liang Dar is capable of achieving a smoother cutting surface, less chipping and higher precision, which is highly appreciated by the Japanese and other customers and choose to work with us.

Ans

Impedance (denoted as z) refers to the total opposition of a circuit to the flow of alternating current (AC) at a specific frequency. Impedance is measured in ohms (Ω), just like resistance. Impedance in alternating current (AC) is similar to resistance in direct current (DC), but they are not the same. Impedance refers to the ratio of the potential difference across two points in a circuit (including assembled components) to the current flowing between those points. Impedance is composed of resistance (R) and reactance (X). Reactance is indeed a combination of inductive reactance (XL) and capacitive reactance (XC). The graphical representation and formulae are shown on the below.

 

The line conductors on circuit boards carry various low-voltage signals and "characteristic impedance" is the resistance they encounter, which is also often referred to as "impedance". To enhance transmission rates, frequency should be increased first (an increase in cycles instead of energy). When the circuit is etched, variations in the cross-sectional area of the traces and inconsistencies in the thickness of the dielectric layer can lead to changes in characteristic impedance and signal distortion. Therefore, in high-speed circuit boards, the characteristic impedance values of the conductor circuits should be regulated or controlled within a specific range to ensure optimal performance. Common values for characteristic impedance include 50±5Ω or 50±3Ω. This practice is called "impedance control", a special requirement to ensure the quality of PCB.

 

Ans

High-density interconnector PCB (HDI PCB) is a high-density circuit board with high wiring density. Liang Dar is capable of manufacturing 1-stage and 2-stage HDI boards, which are also called boards with blind and buried vias. We can manufacture multi-layer PCBs with through holes between different copper layers. For example, L1~L2 and L5~L6 blind vias, L2~L3, L3~L4 and L4~L5 buried vias in 6-layer PCBs. However, our ability to manufacture highly depends on Gerber files, copper thickness specifications, aperture table, and so on.

Ans

At Liang Dar, with mechanical drilling, our stabilized process ensures 0.2mm diameters, with 0.15 mm being the smallest diameter we are able to create. For smaller holes, laser drilling should be considered. Laser drilling can stabilize at a 0.05 mm hole diameter. However, to design the size of drilling holes should take plated through holes or blind ones into account.

Ans

The minimum corner radius for CNC milling is 0.5mm. The minimum corner radius using the punching method is 0.3mm. The minimum corner radius using the punching method for metal core boards is 1.0mm.
 
 
 
 

Ans

With finished copper thicknesses under 1 oz using the negative exposure process, a minimum trace width of 75 µm (3 mil) can be achieved. With Laser Direct Imaging (LDI) technology, the minimum trace width can be 35µm or less, contingent on the capabilities of the equipment and the overall manufacturing process.