The project is from a Denmark customer,begin with a project of PCB reverse engineering. We do it successfully and pass the test. Now the customer release a mass production order 1000pcs.
The PCB is used for household electrical appliances control. There are many connectors to connect with house electrical appliances.There are two display version on the PCB board. We could see and control the working status of various household appliances. Check the power consumption, power, working hours, etc.
The difficulty of this project is that, it is a PCB clone project at first, and many contents need to be confirmed and repeatedly considered.There are more than one hundred kinds of components, the value and accuracy of each component must be crucial. Any error will cause the product can’t work.
It is 1.6mm thickness 4 layer PCB, 15.5mm*20mm, TG130,1/0.5/0.5/1oz copper thickness, HASL, solder mask green, silk print white. Fabricate per IPC-6012 Class 2, punch tooling hole registration tolerance +/-0.005. Conductor width tolerance +/-20%. The fabrication shall be UL approved.
We checked the BOM list, and try to use alternative components. As some components could use alternative ones with same specification, same quality, but lower price. We change manufacturers of connectors, resistors, capacitors, battery holder and heat sink. It is a good way to save cost for the project.
The IC and BGA we used are the same as original sample. We need to do some pliers processing before assembly work, the capacitors’s diameter must be 8mm and the resistor must 3mm higher than PCB board. There is a BGA component that we must pay attention to when assemble, the ball diameter is 0.3mm which is difficult to solder. The BGA needs to be stored and cleaned in a dry environment, It should not be touched by hand or other objects to prevent the ball from being deformed or contaminated by grease. We use an oven to preheat BGA to remove moisture.
The diameter of the stencil is larger than the solder ball’s, such as a 0.6mm solder ball, the diameter of the steel mesh should be 0.7mm, and the thickness is 0.25mm.
When the solder ball reaches the melting point, it will be in a liquid state. If the solder ball is too long or the temperature and pressure are too high, the surface tension and supporting effect of the solder ball will be destroyed, resulting in the chip completely landing on the PCB pad during reflow then cause short circuit occurred. Therefore, we need to appropriately reduce the welding temperature and time in the last zone or reduce the bottom preheating temperature.
Since the BGA solder ball has tension, when soldering, the temperature of the reflow solder must be maintained for a period of time. It cannot be stopped immediately after soldering, decrease in temperature will result in poor soldering of the ball and the pad. To ensure that the solder ball melts evenly, fully solder on the pad and then stop the machine. At the end,we use X-RAY to check the BGA, all of them are ok.
With just one device, you can control all your home appliances and watch their power consumption and working hours at any time. It is easy and convenient to open or turn off ones. We are still pursuing the performance and convenience of electric products. From a purely remote control device to an integrated control device, it will become more and more widely used in future.
Contact Us for your PCB Reverse Engineering Project
- No.13-1 Youquan Road,
- Zhanqian Street, Jinzhou District,
- Dalian, China