Active Member
|
[China]
Address: Room 1520, Block 11, International E-Commerce Logistics Center, PingAn Road, PingHu Street, LongGang District, ShenZhen City, China 518111
Contact name:Steven YU
Witgain Technology Limited |
|
|
2 OZ Copper Power Supply Product PCB Double Layer Circuit Board
1 2 Layer FR4 substrate material printed circuit board.
2 Double layer copper, copper thickness is 70um/70um.
3 Finished pcb thickness is 1.6mm.
4 Used in power supply product..
5 ENIG+Carbon ink surface treatment.
6 2 layer pcb with 7/7mil min line space and width.
7 Green solder mask and white silkscreen.
8 Need customer to send us the gerber file or PCB file
| NO | Equipment Name | Equipment Brand | Equipment QTY |
| 1 | Automatic Cutting | SCHCLLING-CA6858 | 1 |
| 2 | Roll Cutting | QIXIAN | 2 |
| 3 | Vertical Cutting | SHANGYUE | 2 |
| 4 | Innerlayer pretreatment | JIECHI | 4 |
| 5 | Automatic coat&wiring | QUNYU | 4 |
| 6 | Automatic exposure | CHUANBAO | 11 |
| 7 | Large table exposure | HECHUAN | 2 |
| 8 | Laser Plotter | ORBOTEC | 3 |
| 9 | Etching line | KB | 4 |
| 10 | PE Punching | PE-3000 | 1 |
| 11 | AOI | ORBOTEC | 10 |
| 12 | Double row brown | KB | 3 |
| 13 | PP Cutting | ZHENGYE | 5 |
| 14 | PP Chopping | ZHONGDA | 2 |
| 15 | Hot-melt machine | HANSONG | 6 |
| 16 | Riveting machine | JIAOSHI | 6 |
| 17 | X-Ray Check | HAOSHUO | 5 |
| 18 | Automatic reflux | LANDE | 2 |
| 19 | Steel plate washer | FENGKAI | 2 |
| 20 | Large size press | DATIAN | 8热4冷 |
| 21 | X-Ray Drilling target | HAOSHUO | 8 |
| 22 | Ccd Drilling target | XUELONG | 10 |
| 23 | Automatic grinding | XINHAO | 5 |
| 24 | Plate thickness Measuring | AISIDA | 2 |
| 25 | Four axis gongs machine | DALIANG | 2 |
| 26 | Two axis gongs machine | BIAOTEFU | 4 |
| 27 | Automatic grinding mill | JIEHUI | 2 |
| 28 | Drilling machine | TONGTAI | 13 |
| 29 | Hole testing machine | YAYA | 1 |
| 30 | Sinking rough mill | KB | 1 |
| 31 | Vertical copper wire | YAMEI | 1 |
| 32 | Automatic electroplating line | JINMING | 1 |
| 33 | Dryer after electroplating | KB | 1 |
| 34 | Etch machine | KB | 1 |
| 35 | Film checking machine | YUBOLIN | 2 |
| 36 | Line pre-processing | KB | 2 |
| 37 | Automatic laminator | ZHISHENG | 3 |
| 38 | Outer exposure machine | CHUANBAO | 8 |
| 39 | Outer exposure machine | HECHUAN | 3 |
| 40 | Etch machine | JULONG | 1 |
| 41 | Line developing machine | KB | 1 |
| 42 | Sand blasting machine | KB | 1 |
| 43 | Precoarsening pretreatment | KB | 2 |
| 44 | Electrostatic spraying line | FURNACE | 1 |
| 45 | Automatic screen printing machine | HENGDAYOUCHUANG | 12 |
| 46 | Pre baked tunnel furnace | KB | 1 |
| 47 | Solder resist exposure machine | CHUANBAO | 6 |
| 48 | Solder resist exposure machine | HECHUAN | 2 |
| 49 | Post baked tunnel furnace | GC0-77BD | 2 |
| 50 | Solder resist developing machine | KB | 1 |
| 51 | Screen printing machine | 1.8mm/2.0mm | 4 |
| 52 | Character baking tunnel furnace | GC0-77BD | 1 |
| 53 | Sunk Tin spray line | 2 | |
| 54 | Nickel palladium and gold wire | XINHUAMEI | 1 |
| 55 | Alternator | 2 | |
| 56 | OSP line | KB | 1 |
| 57 | Gongs machine | YIHUI | 20 |
| 58 | V-CUT | ZHENGZHI | 1 |
| 59 | CNC V-CUT machine | CHENGZHONG | 2 |
| 60 | Hydraulic punch press | SRT | 2 |
| 61 | Test machine | MASON | 17 |
| 62 | High speed flying needle tester | WEIZHENGTAI | 3 |
| 63 | Four wire flying needle tester | XIELI | 2 |
| 64 | Product washing machine | KB | 2 |
| 65 | Plate warping machine | XINLONGHUI | 2 |
| 66 | Vacuum packaging machine | SHENGYOU | 4 |
Q1: What is Backdrilling in PCB Fabrication?
A1:
Back drilling or Controlled depth drilling is a process used to remove the unwanted portion of a PCB Via Stub. Plated Through Hole (PTH) Vias are used to connect two or more layers of a Printed Circuit Board to each other. However often, a via does not need to run the entire thickness of the board to connect each layer. For example, if we have a 10 layer PCB and need to connect layer 1 to layer 3 using a via, the PTH via runs through all the layers of the PCB even though layers 3 to 10 do not need to be connected to each other using that particular via. This unused portion of the via is called a stub. These stubs can cause significant signal distortion (click here to read more about PCB via Stubs).
Backdrilling is a technique used to remove the unused portion of the stub (conductive plating) in a printed circuit board. This is removed by using a drill that has the diameter slightly larger than the diameter of the original via (PTH) hole. In practice, it is achieved by re-drilling the PTH down to a predetermined stub length of less than 10 mils from the signal layer.
In case the via is connecting two internal layers only, then it is necessary to remove the top and bottom stub to improve the high-speed signal quality (see figure below). Backdrilling is a cost-effective solution as compared to the lamination technique (used for blind and buried vias) to manage the signal quality in a high-speed signal bath. If properly executed, it will not affect the performance and reliability of the PCB.
How does the stub length distort the signal quality?
When a signal flows down the length of a via, it splits into two parts at the junction between the internal layer and stub. One part travels towards the receiver end through the internal layer, and the other part travels towards the stub end. The stub act as an unterminated transmission line, so the signal reflects back towards the junction. At the junction, the signal again split into two with one signal returning to the source, and the other following the trace. Hence, the source signal is disturbed. The source distortion is the main cause for deterministic jitter (deviation clock pulse edge from its original position). Then the deterministic jitter leads to an increase in Bit error rates (BER), cross talk, EMI/EMC radiation, and the attenuation.
