Discovering all about automotive PCB and PCBA
Vehicles use PCBA for a number of reasons and in this article you will go through everything you need to know about automotive PCBs. You might wonder where and why the automotives need PCB at all. In reality, automotives not only rely on mechanical systems, but on electronic systems a lot. That raises the need for the introduction of PCBA and PCB in them.
The increasing number of government norms in every country at an alarming rate has caused a boom for demand of PCBAs in the automotive industry, which is why PCBA manufacturers have upped their game and have started manufacturing automotive PCB and automotive PCBA. What are they exactly? This article reveals all the details.
What exactly is automotive PCB?
Automotive PCB is the name given to a PCB that’s designed for use in vehicles. Whether it’s an electric vehicle, smart hybrid vehicle, or fuel-based (petrol, diesel, CNG) vehicle, they need PCB. The term PCB was coined to differentiate it from other regular PCBs used in other electronic gadgets. Automotive PCB, however, has a lot of unique features and applications, that you’ll be going through below.
An automotive PCB is only manufactured and is suited for use in automotives, which is why it’s called automotive PCB. An automotive PCB is of course incomplete without an assembly, which is called automotive PCBA.
What are the features of automotive PCB?
As mentioned previously, automotive PCB has special and unique features, making it distinct from other types of PCBs. This section elaborates on that.
There are several types of automotive PCBs that are installed in different parts of a car. For instance, a PCB designed for speedometer will be different from a PCB designed for the infotainment system. Each type of PCB will have a special function and reason for manufacturing and will be installed at a special and dedicated place in the car.
The number of types of PCB for an automotive can vary depending on what features the car manufacturer wishes to give in the vehicle.
Vehicles run through potholes at high speeds, which generates a lot of shock. While the mechanical systems are strong enough to withstand all the heavy shocks, the electronic components are pretty fragile. That triggers the need to develop PCB with shock resistance, so the electronic systems don’t fail quickly due to excess shock. It’s very common for vehicles to run into potholes.
Moreover, in order to achieve stability in electronic systems even when the cars crash, their PCBs should be shock resistant.
Car owners would hate it if they’d have to get their electronic systems repaired or replaced. If a PCB ain’t durable enough, the electronic parts of a car would fail sooner than expected. As a result, one important feature of an automotive PCB is durability.
You’ll notice that a car would require oil change, fluid change, or mechanical repair, but would hardly require PCB replacement, all thanks to durable PCBs in them.
Heavy copper usage is very crucial and is a distinct feature of automotive PCB, since the electrical current in vehicles is high. The PCB needs to be using heavy copper plates so there’s enough conductor for high voltage to safely pass through the electronic components. If a car uses light copper PCB, then it’s at a serious risk.
5.Heavy heat tolerance
Car engines generate too much heat despite the use of coolant in them. Heat is the worst enemy of PCBs, and car manufacturers cannot keep the PCB cool enough. Therefore, the automotive PCB tend to work in an extremely hot environment, making it a duty of PCB manufacturers to develop an automotive PCB that has high heat tolerance.
What are the types of PCB for automotive electronics?
1.High Density Interconnect
It’s acronym is HDI PCB, which is usually found in the complex wiring behind your cars’ dashboards. The almost the entire electrical wiring of the car is found behind your car’s dashboard, which is connected through a central PCB called HDI PCB. The HDI PCB is meant to keep all the wiring and components connected to each other to achieve a perfect ratio of cohesion and coupling.
2.Metal Core PCB
Metal core PCB can be aluminum-based or copper-based, or a mix of both. These are installed at places to connect lighting system in the car. Consider all the bright lights such as interior cabin light, head lights, fog lamps, etc., they’re all connected to the battery through MCPCB.
Flexible PCB is always found carrying current through the corners and at places that don’t require heavy electrical current. You might find them in your car’s infotainment system, or connected to LEDs that don’t require heavy electricity. Bright but less lumens LEDs are mostly connected to the battery through flexible PCBs.
How to choose the right PCB for automotive?
Now that you’ve got an idea of features and types of automotive PCBs, let’s jump to selecting the right PCB for your automotive. Below is a list of what you should look for in a PCB when going to select an automotive PCB.
Thermal properties in PCBs imply that they should have good conduction of heat. Good thermal management to achieve proper heat dissipation is highly crucial to keep the PCBs from getting damaged from excess heat. Automotives are all about high heat, and that’s the reason why choosing the right PCB demands verifying its good thermal properties.
Electrical properties imply that the PCB should have good quality conductors of electricity. For instance, use of copper over aluminum and use of thick copper plates over thin copper plates are two examples of a PCB with good electrical properties. Proper flow of electricity ensures no short circuit as the electricity will have sufficient electrons in the metal to ensure smooth flow of electricity.
It’s important to understand where you’ll need flexible PCB and where you’ll need a rigid PCB in an automotive project. Flexible and rigid PCBs have totally different applications and suitability. Moreover, there’s a huge cost difference between both. Make sure that you use flexible PCB only where it’s suited. When choosing the right PCB, first determine if you need flexible or rigid PCB.
Just like resistance to heat, there’s an important factor called resistance to shock. Automotives produce high levels of shocks from engines and cars running in potholes. You might be surprised to know that the PCB also has shock resistance. These type of PCBs are a bit costlier, but in order to ensure durability and quality in your automotive PCB, always go with one with high shock resistance.
Automotive PCB preparation- How it’s done?
Below is a quick rundown of the process of making an automotive PCB, otherwise called automotive PCB preparation.
1.Design and initial preparation
So you might have a design in your mind, that needs to be brought to life. This is done with a pen and paper during the initial phase. For that, you’ll go through several meetings with electronics engineers and designers, who’ll collect your idea and will draft your idea on a paper. That’ll lay a foundation to your PCB.
2.Finding required components
Now that you’ve given your idea and a draft has been laid out, it’s time to find out what electronics components need to be on your PCB. That’ll be helpful later on during PCBA processing.
First, the circuit design will be created and will be optimized to reduce the circuit size and components, that’ll help shrink your PCB board price. After that, a list of components and their placement on the circuit board will be identified.
It’s common for the automotive PCB to have several layers. Layers can include copper plate, ceramic layers, plastic layers, adhesive layers, etc. These layers are prepared and printed separately. Once all the layers are printed, they’re carefully stacked on top of each other as per the initial design. After that, the stacked PCB is baked in a PCB oven, so the adhesive bond becomes strong and the layers become one single PCB layer. That’s why you’ll never be able to separate different layers of a PCB after it’s fully manufactured.
4.Separating the chip from the panel
Once the PCB has been baked and cooled down, the manufacturer might want to cut out the PCB from the PCB panel. A panel is a large sheet of PCB which will have several small PCBs. The PCBs are cut down from the panel.
5.Polishing, solder masking, and finalizing
The polishing work is done, so that the PCB gets a layer of smooth and fine-finish polish. This polish gives a good shiny look and helps protect the PCB from accidental spillage.
The PCB solder mask is applied, so the components can be easily embedded to the PCB later. The solder mask is put with the use of soldering flux, that generates a strong bond between the solder mask and PCB. And now the PCB is finalized, packed, and shipped to the client or sent for PCBA preparation, as needed.
Where can automotive PCBA be used?
Let’s take a look at what wonders can PCBAs can do in automotives. Here’s a brief list:
- Airbag Controls
Electronic sensors are installed and connected to the circuit boards, that trigger inflation of air bags in car when the sensors record shock levels above the set thresholds. This mimics the idea that the sensors actually want to inflate the air bags, assuming there’s been a car crash. This entire function is possible with the help of PCBAs.
- Anti-theft Systems
Cars have so many advanced features to avoid car thefts. For instance, detecting if the car was tried to be opened with a different key, there’s a need for an electronic system, which obviously involves PCBAs.
- Climate Control
Climate control is an advanced feature, where the vehicle’s cabin temperature is maintained to the set temperature. There’s a need for a thermostat, air blower, etc., that are all connected through PCBAs. The role of PCBAs here is to act as a motherboard or a mainboard for this purely electronic feature in the cars.
- Infotainment systems
Infotainment system includes playing songs and music from USBs, Bluetooth devices, FM, AM, AUX, etc., sources. These infotainment systems need an electronic PCBA to function. Therefore, such PCBAs fall under the category of automotive PCBA
- Digital displays
Digital displays include speedometer, warning signs, etc. These are electronic features, that are again, impossible to develop without a proper PCBA.
Automotive PCBA preparation- How it’s done?
The process of automotive PCBA preparation is the continuation of PCB preparation.
1.Embedding all the components
The list of components that need to be put on the circuit board was already created previously. It’s time to assemble the PCB with them at their suitable places. Using a fine pin soldering machine, the components are soldered with perfection by melting the solder mask already present on the PCB.
As a result, the pins of the component passes through the molten solder mask and the soldering pin is removed, so the solder mask hardens instantly. That’s how components are soldered.
2.Testing the functionality
Once the components are assembled, the PCBA is ready for use. But before that, a testing phase is conducted, so that the working of PCBA can be verified. This step is necessary to ensure that the PCBA has no faults and that it works according to the requirements.
The PCBA is then finalized as it goes through final etching, and other minor necessary steps. It’s packed and shipped to the client.
Some automotive PCBA design guidelines
1.Always embed large components first, followed by smaller components (in decreasing order).
2.The neutral and power planes should be on the innermost layers.
3.There should be a heatsink for components that generate a lot of heat.
4.The solid-filled vias should be used for extended thermal conductivity.
Factors affecting cost and quality of automotive PCBA
There are several factors that can affect the automotive PCBA cost and quality, which are listed below.
- The quality of electronic components highly influence the overall PCBA cost.
- If you’re using expensive components, then the cost will rise.
- Use of new technologies in PCBA is generally the culprit behind rising PCBA cost.
- Addition of extra components such as heatsink, etc., will increase the cost, but will result in promising quality of your PCBA.
- Thick copper plates are generally the reason why cost and quality both increase.
How to choose the right automotive PCBA manufacturer?
Always go with an automotive PCBA manufacturer, who has the following qualities:
- Go with a manufacturer, who gives clear and transparent quotes at the earliest. Always prefer a manufacturer, who sticks to their words and won’t optionally changes their prices halfway during the order and PCBA manufacturing process.
- The right PCBA maker will give fair estimates of shipping in advance. Shipping isn’t where the makers should be making high profit margins. If your PCBA maker can help you shrink the transportation cost, then he/she is a good manufacturer.
- A good manufacturer is one, who uses quality raw materials to make sure that the PCBAs don’t fail in the automotive.
After going through elaborative description and insights into automotive PCB and PCBA, perhaps you’d like to connect to an automotive PCBA maker. That’s where IBE Electronics will come into action. IBE Electronics has years of expertise in automotive PCB/PCBA manufacturing, and they can help you with your automotive PCBA needs from scratch to end.
- IPC-4101: Specification for base materials for rigid and multilayer PCB;
- IPC-6012DA: Standard for ensuring the reliability of circuit boards exposed to high vibration and heat
- IPC-A-610: Acceptability standard for electronic assemblies
- JEDEC J-STD-020: Standard reference from the electronics manufacturing industry
Some factors we should consider such as thermal cycling, thermal shock, and temperature humidity.
- For example, heavy copper PCB should consider thicker copper layers for better performance like high temperature and other variation.
- Aluminum has prefer electrical insulation and thermal conductivity capabilities. It’s a good choice for automotive PCBA substrate materials.
Better shock resistance, high durability, high heat tolerance and other features.