Project Description

Project Background

This PCBA is made for one of our Brazil clients. It is use for car audio. This customer is specialized in manufacturing household and car audio, and is well-known car audio brand around the world.

Product Production

The board material is FR-4 with TG130-140, the surface finishing technology is Lead-Free HASL RoHS. The thickness of board is 1.6mm.

The color of solder mask is green. Silkscreen is use white, permanent, organic, non-conductive ink as the customer required. It has 2 copper layers; the copper thickness was 1 OZ for each layer. The size of single PCB is 214mm*95mm. We designed as 2 single PCB in one panel. All panels be V-scored with 7mm edges on each long side of the panel Dimensions and tolerances are per ASME Y14.5-2009. There are many soldering pads on this PCB, the number of electrical detection points is also a lot. Test 100% for opens and shorts. We have a test frame for this PCB. We fabricate and test to IPC class 2 standards.

The pin spacing of components of this project is not particularly dense, the distance between pins is greater than 0.5mm, and there is no BGA. The thickness of the stencil is 0.12mm.

This PCBA is a double-sided SMD and double-sided plug-in. To begin with, we need to SMD one side. And then the other side. SMT technicians visually inspect each board as it comes out of the reflow-soldering machine. After SMT’s preliminary visual inspection, the QA technicians will inspect both sides of all the PCBAs.

After QA checks SMD, it will be transferred to DIP soldering. All LED lights must be at the same height, and the isolation pillars should be installed on the lamp legs to prevent short circuits and also prevent the lamp posts from being skewed during transport or use(as we all know that cars may be bumpy when they are moving on a rough road). We cut the led leg to the same height as the customer required and put on the isolation pillars. All this work will be ready before the DIP.

Product Assembly

In terms of assembly, this PCBA is not difficult, with a high yield rate. It does not require us to install the chip program, but it must be very well functional tested before shipment. The customer provided us with a detailed description of the test procedures. The necessary test equipment and adaptor are:

 Adaptation board to power the board. The voltages needed are: +5,00 V, +15,00 V and -15,00 V (all ±5% tolerance).

 Calibrated AC voltmeter (true RMS type)

 Calibrated ohmmeter (at least 100,00 kΩ)

 Calibrated function generator (one sine-wave output is needed)

Test Procedure

Disconnect the PCBA from the adaptation board, to test the resistance between pin 1 and 2 pin 2 and 3 in the connector CONs. (The data must be within the parameters and precision provided by the customer):

 Connect the board to the supply and power it on. To press each switches separately, and check if the LED be powered on in the correct color.

 Rotating the knob fully clockwise in turn to give the corresponding sine wave, test the amplitude of the solder plate, and then completely rotate the knob counterclockwise to test the amplitude after giving the corresponding sine wave. Each knob in turn needs to do this step. At the same time, press the corresponding switch to check whether the STATE of the LED is correct when each knob rotates at different positions and gets sinusoidal waves with different amplitude.

 Rotate the button counterclockwise completely to give another sine wave value and test the VOLTAGE of PCBA.

There are 37 steps. Each board took an average of 15 minutes to test. At the first batch of this project, we tested and found that some of the values were different from the reference range in the customer’s guidance. We immediately reported the problem to the customer, and the customer’s engineer updated the test guidelines to us after their analysis. We are currently using the third and final version of the guidelines. This is the data report of this project. Each PCBA has a lable one the bottom side, which shows the manufacture name, date code the testing file reversion and the part number of the PCBA. We scan the test data of each batch of PCBAs to the customer before shipment to facilitate the customer to check and trace the source.

Our PCBA packaging is usually PP foam protected. At the sample order’s shipment, we used PP foam wrapping protection, and then made the separator with cardboard according to the shape of PCBA. However, after the customer received it, it was found that the two LED lights were broken in transit. We analyze that it may be cardboard deformation caused by extrusion and violent loading and unloading during transportation, which may lead to LED damage.

Later, we made an insulated blister box for the PCBA, which fits its shape better and is more durable. After the modification of the packaging, every board received by the customer is intact.

The customer is very satisfied with our solution.

This customer has two series of car audio control panels produced in our company, and we produce several batches every year. This is one of them. The new series has developed and we have produced the sample PCBAs for them to test.

About 86PCB

86PCB could supply one-stop service, including PCB board making, PCB Reverse Engineering, components sourcing, SMT assembly work, Program+Test, housing making, housing assembly…

We aslo have ERP system to manage every project from production file, quotation, purchase, production, delivery until service after it. Date will be found quickly and precise no matter when client wants to begin project.

If you have related projects, welcome to inquiry us to get free quotation.

Susy
SusySales Engineer
Collating all the information, to ensure orders’ the production and delivery successfully.