Automotive PCB fabrication

Automotive PCB fabrication

What is Automotive PCB?

Let us begin by explaining the meaning of a PCB.

Printed Circuit Boards is a non-conductive board with all the electronic and electrical components. The electrical components connect to the board through a physical support aid.

An automotive printed circuit board is a complex circuit system that controls most of the electronic operations in a car.

Figure 01-PCB Systems in cars

In the past many vehicles were using standard rigid automotive printed circuit boards. Modern cars have more than that you will learn in the next segment of this guide.

Automotive PCBs are within complex systems and facing extreme temperature, dirt, chemicals and moisture, every technological improvement needs to concern high-reliability, better control, and care in automotive design. Years before, traditional vehicles use standard rigid printed circuit boards, but now new generation PCBs like HDI(Every-layer Interconnect) boards, flex, and Rigid-Flex are widely used in every part of your vehicles, such as GPS systems, sensors.

GWT-Your Leading Automotive PCB Supplier In China

As a leading automotive PCB manufacturer with ISO/TS16949 compliant, we support PCB and PCB assembly from prototyping to mass production for all your automotive PCB projects, by providing standard rigid PCBs, flexible circuits and rigid-flex solutions to automotive manufacturers and their suppliers. 

We at GWT deeply understand the automotive industry,  you can expect high-quality automotive PCBs with on-time delivery, reliable, and traceable and strict process control solutions with the economic cost.

What Applications for the Automotive PCB?

Different applications of vehicles are using in automotive PCBs. It can be stated that when it comes to applications, PCBs could be considered as the backbone of the electrical system.

The belows is the list of the main applications of automotive PCBs.

1.GPS kit&ECU modules.

2.Displays (Digital)&Sensors of transmission.

3.Radar system&Audio and stereo components.

4.AC/DC converters&Engine controls.

5.Engine timing system&LED system.

6.Occupant detectors&Power distribution board. manufacturing.

Applications of the Automotive PCB

The automotive PCB is a system that you will find in different applications in a car.

In fact, when it comes to the applications, you can clearly understand why PCB is the backbone of electronic components.In a car, most of the electronics have the automotive PCB performing different functions.This segment of the guide will inform you of some of the applications that depend on the automotive PCB.

1.Power relays

2.Vehicle sensor systems

3.GPS systems

4.ECL/ECU control modules

5.Antilock brake systems

6.Digital displays

7.Transmission sensors

8.On board radar

9.Stereo and audio components

10.DC/AC power converters

11.Engine timing systems and Engine controls

12.Electronic mirror controls

13.Interior LED lighting systems

14.LED head lights

15.Occupant detectors

16.Stalk switches

17.Instrumentation

18.Door latch or locking systems

19.Comfort systems

20.Infotainment systems

21.Emergency assist systems

22.Airbag deployment

23.Electronic mirror controls or automatic dimming

24.Power distribution junction box

25.Remote diagnostic systems

In essence, the entertainment, lighting, security and other key features of your car depend on the automotive PCB.

Automotive PCB Design Considerations

This far, you already know that electronic elements play a very important role in the automotive industry.In fact, a modern vehicle has about 200 electronic control units such as processors and sensors.

To achieve this, manufacturers consider different designs for the automotive PCB.

Here, we are going to take you through the design considerations of the automotive PCBs.

Quality Assurance Requirement

From an international perspective, the demand for quality products from manufacturers and distributors depend on ISO9001 regulations.To be more specific, the quality administration system that govern the automotive industry id the ISO90001/TS16949.

It integrates special requirements and focuses on defect prevention, waste reduction and quality fluctuation in the automotive industry chain of supply.

As an automotive manufacturer, you have to obtain the ISO/TS16949 before genuinely entering the market.

To define a product under class 3, You must build it under the total IPC criteria.  IPC class III standard dictates quality standards for:

1.Selection of laminates

2.Plating thickness

3.Manufacturing processes

4.Arrangement of facilities such as components on the PCB

5.Criteria of Inspection

6.Material qualifications

Basic Performance Requirement for Requirement on Performance

In this case, the main factors to consider include:

i.High Reliability

Automotive reliability comes in 2 major aspects.

One involves the long service life where electronic components and control units can last.

On average, the service life of an automotive ranges between 10 to 12 years. During this period, you will have to replace the vulnerable parts susceptible to damage.

An automotive PCB should be strong enough to last the service life of the actual automotive.

The other one involves environmental resistance that allows electronic components and automotive control to perform excellently in harsh environments.

It should be able to survive extreme heat and cold temperatures among other environmental conditions.To determine the condition of the automotive PCB, you can perform a series of tests. These include thermal cycling test, thermal shock test, and temperature humidity bias test.

ii.Miniaturization and light weight

Miniaturization and light weight are very important for saving fuel. You can achieve miniaturization and light weight of PCBs by density and area reduction.You can reduce the thickness of every aspect and use multiple layers as well.

Automotive PCB Designs and Layout

Here we are going to look at some of the factors you need to pay close attention to.These include:

i.Inductor Orientation

Whenever two inductors come close to one another, inductance is generated.

It is, therefore, important to have a design where all the designs in a compact circuit layout. It will ensure coupling balance reduction.Better inductance alignment will ensure will ensure mutual distribution in relation to inductance alignment.

Therefore, whenever you are designing an automotive printed circuit board, you have to follow these rules:

First, the spaces between the inductors have to as large as possible.

Secondly, inductor alignment should be at right angles. This will reduce or minimize any form of inductor cross talks.

ii.Lead Coupling

In case you place leads close to one another, you are likely to affect coupling and generate mutual inductance.

In this case, you have to place the return current path close to the main current path in a minimal radiation field. It will help in the reduction of the current loop area.

You should consider integrated grounding under leads as much as possible. This is because the integrated mass area grounding will improve the performance of the automotive printed circuit board.

iii.Grounding thru-hole

The main issue you will have to solve in this case lies with the bad impedance of different circuits. This may come through different electronic components and interconnections.

Capacitance of the thru-hole is often between the bottom copper and the copper at the edge of the thru-hole. Capacitance of thru-holes is also affected greatly by the cylinder of the metal thru-holes.

Therefore, you should have the inductance module for the thru-hole in a sensitive area. The matching or filter network should depend on independent thru-holes. Lastly, having thin PCB copper will reduce the effect of parasitic inductance.

iv.Grounding and Filling

As an important aspect of the automotive PCB design, you should get the design right. This will help you avoid issues with impedance in the circuit.

When you are designing the grounding and filling, you have to put the following under consideration.

First, you have to provide a continuous grounding area with very low impedance. Secondly, connect the filling wire terminals with the thru-hole array to the ground. Lastly, connect copper coated lines to the ground

With the above design considerations, you are sure of having an automotive PCB that will function well.

Automotive PCB Prototyping

You will need to have an automotive PCB prototype before having the actual automotive PCB.The prototype will guide you in making a good and complete automotive printed circuit board.It will also assist you to know whether the automotive PCB design you need will work.

First, you need to have a design software to assist in coming up with a good prototype design. The software has the key features that you will need in making a good prototype.A designing software such as Eagle, will assist you in making a Gerber file.

--Understand the specs of the automotive PCB you will need

1.You need to specify the dimensions, type of material, number of layers, plating finish, board thickness and impedance control.

2.Apart from that you have to include, minimum spacing, size of holes, minimum pitch, solder mask, silkscreen and castellated holes.

--Check if you have any design rule violation

In this case, you need to have a look at the design rules. With the assistance of the designing software, you are capable of making a great prototype.

Some of the software you will need include eagle (DRC) for prototyping and Free-DFM.

--Generating the Gerber files

With the help of the software, you can generate a blue print of the automotive PCB you need

After that, you need to check your files and ensure that everything is in the right order.

--Document your stack up

With the Gerber files ready, it is time to document your stack up and send it to the manufacturer. Make sure that you arrange and label the layers accordingly.The manufacturer will create the prototype and test if it works properly.

--PCB for Automotive Industry Assembly

With the PCB prototype in hand, you are free to move on to the assembly process.Before you proceed, you have to ensure that the PCB prototype is working perfectly.