Use CFD simulate PCB thermal design

How to handle the thermal management during automotive PCB design?

Making sure that automotive electronics are reliable, safe, and properly designed begins at the component level. Heat must be addressed early in the design process for these goals to be achieved. The most important thermal resistance for heat, outside the IC package, is the PCB. Rich PCB manufacturing engineers use 3D computational fluid dynamics (CFD) to simulate and test a PCB’s thermal design. Modeling the main heat flow paths in detail is critical to ensure that generated heat in the component flows out to the ambient, either through convection, conduction, or radiation. Knowing the thermal junction resistance allows optimizing a design for more efficient and less costly heatsinks, materials, and ICs.

When building a model to use in simulation, different methods can be used to represent chip packages and PCBs. Chip packages are typically defined as four types. The simple cuboid is a lumped component with some material properties and a heat source applied to it. The 2-resistor model doesn’t include any thermal capacitance and is therefore not suitable for transient analysis of component temperatures. The Delphi model is comprised of several thermal resistances and capacitances and thus is more accurate and suitable for transient simulations. Finally, the detailed model is modeled explicitly and is the most accurate model; however, it also increases the simulation time and requirements for computing resources.

For the PCB, four detailing levels from simple to complex also are used in simulation: lumped approximation, individual layers’ representation, layers modeled with “patches,” and copper tracks and areas modeled in detail.

Top three ignore point during PCB manufacturing

This paper HTD PCB manufacturing experts will introduce three misunderstand.
If you have any questions about those Top three ignore point during PCB manufacturing, please feel free to contact us.
Our PCB manufacturing experts will reply ASAP.

1. Engineering design: the PCB design should note:
A. interlayer half curing chips, such as shall be symmetrical arrangement six layer PCB board, 1 ~ 2 and 5 ~ 6 layer thickness and half between the number of curing pieces shall be consistent, otherwise layer after pressing warps easily.
B. produce multilayer prototypes core board and half curing piece should use the same supplier"s products.
C. outer A face and side B circuit patterns should be as close to the area. If A surface for big copper surface, but B surface walked several thread only, this kind of printed circuit board after the etching is very easy to warp. If both sides of the line are far too big, can the area in dilute side add some independent grid, make the balance.
2. Before blanking baked board:
Copper clad material before baking plate (150 degrees Celsius, time 8 + 2 hours) purpose is to remove the moisture in the plate and also make the plank to fully cure within the resin, further eliminate plank of stress, which left to prevent plate wrpping is helpful. At present, many two-sided and produce multilayer prototypes still insist on next makings before or after baking plate this step. But there are some board factory exception, currently the PCB board of the time regulation also baking inconsistent from 4 to 10 hours, according to the production, the suggestion to the class of the PCB and client requirements to decide the warping degrees. Baked or cut makeup; after block after baking feeding, two methods are feasible Suggestions after cutting materials, baking plate. Lining board should also be baking plate.
3. Half curing slice of weft to:
Half cured by slice layer after pressing zonally shrinkage to and material and, as must distinguish the stack layer to and a zonally. Otherwise, layer after pressing is very easy to create the finished product, even add pressure plate wrpping baking plate also hard to correct. Produce multilayer prototypes of reasons, many warping is laminated half curing chips when pyrocondensation, disorderly diego to didn"t distinguish caused by the release.
How to distinguish jinwei to? Volumes of half cured by the direction of tablet is up to, and width direction is a zonally; It long sides of copper foil board zonally, when the shorter edges is to cannot be determined by, such as producer or supplier to query.

HTD Group explain Gold Finger PCB technology

HTD Group is professional gold finger PCB manufacturer from China.
This paper will discuss gold plate technology.
If you want to learn more, please mail to info@htdcircuits.com

Gold contact surfaces are often used on circuit boards with membrane switches which are a technology of choice for industrial, commercial and consumer products. When PCBs will be repeatedly installed and removed electroplated gold is used for edge-connector contacts or as they are more commonly known: Gold fingers.
It is difficult to hear the term Gold finger without remembering the villain Auric Goldfinger from the James Bond film of 1964.
However, the gold fingers (gold-plated contact pins) found on PCBs are quite unlike Auric’s stubby, fat digits.
To begin with, the plating thickness of a PCB gold finger is typically a mere 300 micro-inch. At this thickness the hard gold is expected to survive 1,000 cycles before wear through.

How to design a wearable high-speed board?

Developing A Wearable High-Speed Board
The US Air Force engaged HoloEye Systems to create a prototype binocular holographic waveguide visor display (HWVD) attached to the helmet worn by a pilot of an Air Force jet.

Advanced sensors throughout the aircraft generated key info that the pilot needed.

This helmet-mounted display (HMD) presented a heads-up display of instrumentation and digital representations of important data.

The helmet was the heart of the aircraft, enabling the pilot to take advantage of the whole system.

This cutting-edge technology significantly decreased the cost, volume and weight of traditional helmet-mounted displays, replacing bulky optics systems with thin, light-weight, see-through diffractive optics.

The headset display was one of the first reported binocular HMDs in development using a liquid crystal and silicon (LCOS) microdisplay.


PCB Requirements
The helmet-mounted display supported the PCB in its mechanical housing, and an HDMI cable fed into the video source.

An optical cable connected to the display, which carried light to the headset’s LCOS microdisplay.

The light illuminated the display and was projected onto waveguides that presented information to the pilot’s eyes.

PCBs Are on a Huge Demand in Modern Technology

One of the basic concepts of the electronic circuits is the printed circuit boards or PCB. It is such a fundamental concept that we often forget to define its importance in modern technology. But whatever it is, we can’t get over the essentiality of the PCBs in modern electronics. However, PCBs have made our job simpler by its durability, reliability, and multi-purpose usages. There are a lot of tasks that was tough earlier but after the invention of PCB, it seems to appear much effortless.

Along with the rapid development of technology the modern era of electronics seems to be amazing. Throughout the electronic industry, Printed circuit boards are used. So there is a high demand of PCBs in the industries as well as at individual level. PCBs are used in many fields of modern civilization. They are used in computers, cell-phones, GPS systems, broadcasting, scientific instruments etc. automotive industry, defense, medical industry and marine instrumentations. Naturally, mass production PCB is on high demand.

As the usage of PCBs is spreading day by day, lots of researches are being done on the field, and new types of PCBs are being developed. PCBs can be of one layered and multilayer. They can be comprised of a number of layers: generally from 2 to 12. PCBs can also be printed on one side or both sides. PCBs can also be rigid, flexible and rigid-flex type.

During the last few years, there is a noticeable growth in the electronic markets of china. They seem to develop their business a lot. There are numerous PCB manufacturers in china who are spreading their business all over the world. There are a lot of alternative companies in the electronics market of china but the HTD circuits has been proved themselves to be capable of standing out of the crowd. They have become a top ranked choice in electronics market through the last 15 years of experience and hard work. Their professionalism and dedication towards the work have been able to gain customer satisfaction and reliability. While there are thousands of other PCB manufacturers in china they are solely different.

HTD circuits have maintained themselves to serve the overseas customers also, which had been a great challenge for them because of the difference of time zones and the availability of multilingual staffs. They take online orders and they can produce from 2 to 12 layered PCBs. All of the PCB fabrication processes are done under strict quality control measurements. You will also be surprised to know that they provide you the high-quality PCBs within your budget.

They are also open to the service of custom PCBs, where the customers can choose the dimensions of PCBs according to their choices.

Six common sense of PCB E-testing introduces

Here are some of the key terms that you need to know.

Net: An entire string of points or connections from the first source point to the last point including component lands and vias.

Net list: A list of alpha-numeric locations that are used to describe a group of two or more points that are electrically common.

Shorts Test: Check to make sure that NO current flows between separate nets by measuring the amount resistance between them.

Opens Test: Check to make sure there is current flow from one “node” to the next for every net on the board.

100% Net List Test: Check of every “node” on every net on the board.

Optimized Net List Test: Check every “end of net” for all nets on the board and selected intermediate nodes on the board.

IPC provides guidelines on how bare circuit boards should be tested.
Here is a copy of the guideline.

“IPC- 9252 Guidelines and Requirements for Electrical Testing of Unpopulated Printed Boards”

“Section 4.4 States: One hundred percent continuity and isolation electrical test is the confirmation that the actual electrical interconnect of conductive nodes matches a proven reference source, including but not limited to CAD/CAM digital data, master pattern artwork, or released drawings.”

Source: linkedin

The tips of PCB assembly

In automatic cartridge online, if uneven PCB, can cause positioning prohibit, components cannot cartridge into the hole and surface sticks bat ZhuangHan plate, and may even be automatic inserts installed crash.
Mount components happened after the board welding, element is difficult to cut bending feet flat and tidy.
Board cannot fit into device inside the case or socket, therefore, also is met board become warped potential manufacturing/remanufacturing troubled.
At present, the PCB enters the surface installation and chip of the era, installation of potential manufacturing/remanufacturing of curved requirements must board more strictly.

How to Measuring Impedance in PCB Manufacturing Process?

There were so many guys don't know measuring impedance.
This paper we will discuss How to Measuring Impedance in PCB Manufacturing Process.

Measuring Impedance

Testing the impedance values within your PCB is not always easy.
Various factors such as accessibility, via connections, branches off tracks and length of traces can make getting an accurate reading difficult

Test Coupon: is manufactured on the same panel as your PCB and will contain the same trace characteristics as the traces requiring impedance control on your PCB.

A Time Domain Reflectometer (TDR) is the most common method of measuring impedance.
Basically this sends a signal along a line and then measures the part of the signal that is reflected back when an impedance mismatch occurs.