The following tasks are our general process of pcb assembly job. Our sales representatives have worked as engineers in electronic manufacture industry for years before. They must participate in below production process of the order, worked as a NPI engineer (New Product Introduction) in production process. No any communication obstacle and our professional technical support is always around you. So we process your order just like build the project in your next door.
1. Review and quote order.
Our team enquiry,discuss,review and understand all detailed technical information and customer's requirements about the order,such as PCB specifications,BOM list,assembly instructions,etc.Then estimate cost according to order information and prepare offer sheet."
2. Confirm and pay the order.
Customer check prices on offer sheet. If it is accepted,we will send a commercial invoice,with customer address,our company bank account and some other related information printed.We highly recommend wire transfer.Remember to send the wire transfer receipt to us,then we can promptly proceed with the order."
3. Arrange the order
3.1. CAM engineer audit and prepare PCB production files (optimize according to DFM rules and panelize single PCBs). PCB in panel format is widely used for SMT line and assembly steps .This can improve pcb fabrication and pcb assembly processes . At the same time,our assembly process engineer review the board by combining Gerber files,BOM sheet and centroid file. Engineering question (EQ) will be asked if our he find any issues on the project. Also a completed working instruction must be issued by the process engineer,such as assembly direction of indeterminated polarity for chip and connector.
3.2. Start to produce bare PCB,SMT stencil,and purchase components.Prepare pick and place program to assemble SMD component by machine."
4. Incoming inspection for SMT stencil,bare PCB and electronic components.
For bare PCB and SMT stencil,we inspect according to standard IPC class 2. For electronic components, first we need to read datasheet.Then we use a magnifying glass or microscope to identify any obvious defects that are seen by the naked eye, such as cracks,oxidized pins.
We also check silkscreen on top side according to the datasheet.
5. Start assembly job. First article inspection and confirmation if necessary(Top side and bottom side).
For first assembled board (only with components placed,not reflowed and soldered), both of our assembly engineer and process engineer must confirm independently to ensure all parts placed in their place and in right directions. Further more,our sales representative will send you detailed pictures of the board for confirmation.
6. Visual and AOI inspection after all SMD part assembled.
QC department inspect each board, each SMT solder point by AOI machine,from top side to bottom side.
7. Manual soldering for through hole part and board washing.First article inspection and confirmation if necessary(Top side and bottom side).
Generally, sales representative send you pictures of first board with all through hole part soldered. Manual soldering work start after getting your confirmation.We use specialised water to wash manual soldering point.It is environmentally friendly and low conductivity.
8. Visual inspection for Manual soldering part.
QC department inspect each board, each manual soldering point by eyes, from top side to bottom side.
9. IC programming,functional test,conformal coating or other special process applied.
Commonly,customer need to prepare a document for above works. Our engineer will start some PCS first, just a trial-production.Then detailed Chinese working instructions will be written for workers,internal use only.
We are not be fimilar with the design. So professional technical support is needed and helps to speed up production progress.
10. Packing board carefully and arrange shipment.
In order to protect board from being damaged, red bubble wrap(anti-static) and folding box are widely used to pack boards. Our experienced workers will try their best to ensure all boards are well packed. Then sales representative discus shipment with customer deeply.
