Describe the Manufacture Process of Double side PCB

Step 1 : According to the production instructions, cut the large copper clad plate into the size suitable for production；
Key control: size, copper thickness, plate thickness, warp and weft direction。
Key machine: USE PCB board cutting machine ,Another option Electric metal shearing Machine .

Step 2 :eliminate the internal stress of sheet metal, prevent the sheet from warping, and improve the dimensional stability of the sheet。
Key machine: Hot air circulating drying Oven.

Step 3 :Edge shaping ： The edge of the production board shall be smooth, and there shall be no dust and garbage on the board surface after washing; there shall be no scratch on the board surface and residual drape front
Key machine: PCB Edge shaping machine.

Step 4 :drilling hole
According to the requirements of engineering design, for the interconnection of PCB layers, conduction and finished product plug-in, installation, and drill holes that meet the requirements。
Key machine: CNC drilling Machine .

Step 5 :Grinding Board
remove the burr of the hole, clean the dirt on the plate surface and the dust in the hole, etc., so as to provide a clean surface for the subsequent copper deposit layer to adhere well to the plate surface and the hole.
Key machine: PCB Brushing Cleaning Machine .

Step 6 :PTH/Panel Plating
In order to ensure the reliability of interconnection between PCB layers, we use self catalytic oxidation-reduction reaction to deposit a thin copper layer in the hole and on the surface of PCB. At the same time, we use the electrochemical principle to thicken the copper layer in the hole in time. Realize the hole metallization, and make the double-sided and multilayer boards realize the interconnection between layers.
Key machine: PTH /Copper plating equipment.

Step 7 :Photoresist Coating.
1.If dry film is used, a dry film laminator machine can be used.
2. If using wet photoresist ink , you can use a silk screen printing machine for PCB

Step 8 :Exposure.
Single-side exposure, mass production can use single-side-LED-Exposure-Unit , saving energy, no heat, high efficiency .

Step 9 :Developing
photoresist developing machine

Step 10 : Etching
to remove the exposed copper ,Get the required graphic circuit . Usually etched with ferric chloride,or Copper chloride and Ammoniaphoto chemical Etching Machine for PCB

Step 11 : Stripping

Remove the ink covered by the formed circuit pattern to obtain the required copper pattern circuit.stripping cleaning drying machine

Step 12 : Target Drilling Positioning hole

Function: use for drilling hole in PCB board ，these hole is use for Locating pin Solder mask silck screen print .
key machine：Semi Automatic Target Driller key machine： Automatic Target Driller

Step 13 : Pattern Plating

Based on the principle of electrochemistry, a certain thickness of metal (copper, tin, nickel, gold) is plated on the surface and hole of exposed copper, which makes the interconnection between layers reliable and has the characteristics of corrosion resistance, weldability and wear resistance.

Step 14 : AOI

Function: Use optical principles to compare engineering data Perform precise inspections to identify defects. .

Step 15 : solder mask printing

Function: to form a uniform layer of solder resist ink on the circuit board through screen printing。 key machine：silk screen printing machine for PCB . key material：Photosensitive solder resist ink

Step 16 :component printing

Function: screen printing on the board to form a uniform thickness of text ink. Working principle: screen printing (commonly used), spraying Key equipment: silk screen printing machine for PCB to achieve the required hardness and adhesion through baking。 Working principle: heating furnace low temperature baking Choose the drying equipment according to the properties of the ink . UV curing machine for PCB and Hot air circulating drying Oven

Step 17 : V-cut

Function: process the V-shaped pit on the PCB, which is convenient for the customer to decompose the PCB delivery unit into the smallest finished unit after installation. Working principle: manual / CNC V-CUT cutting . Key equipment: A. Manual PCB V Grooving Cutting Machine B. CNC V-CUT machine

Step 18 : Electrical Test（E/T）

1)board cleaning： Function: wash away the dust left on the board surface; clean the board surface for electric contact,Ensure test yield.
2)testing: Function: to ensure that the electrical connection performance of the product meets the user's design and use requirements.

Step 19 : Antioxidant（HASL or OSP or Rosin coating)

Function: provide the deposit layer with good oxidation resistance and weldability, and provide a good welding surface for the downstream patch.

Key equipment: A.Hot Air Solder Leveling Machine. B.OSP line C. Rosin coating machine