4 Layer PCB
Four-layer circuit board is a kind of Printed Circuit Board. It is made of four layers of glass fibre, which can reduce the cost of PCB.
There are also great differences between the 2-layer and 4-layer PCB. For details, please click: What's the difference between 2 layer and 4 layer PCBs?
4 layer PCB stackup include two inner layers, inner layer 1 and 2, are sandwiched between the top and bottom layers. From top to bottom, the 4-layer PCB stackup like below ,The top, i.e. the signal layer (0.0014 in. width) is followed by a prepreg layer with a thickness of 0.0091 in. and dielectric constant of 4.2. The top layer is copper material. The prepreg layer is followed by inner layer 1 (0.0014 in.), referred to as the plane. A core sublayer is part of inner layer 1, which has a width of 0.037 in. This is followed by inner layer 2, which is another plane layer made with 1 oz. copper and is 0.0014 in. thick. Another prepreg sublayer constituting two sheets that are 0.0091 in. thick forms part of inner layer 2. The final layer, the bottom layer, is also 0.0014 in. thick, and is a signal layer as well. Interconnects are soldered and placed on the top and bottom layers.
The standard 4-layer PCB stack is shown below, and GND and VCC can be switched according to the layer with more signals.
If you don't want to connect all the ground pins through the hole, there will be different stacks and wide power routing on the signal plane.
4 LAYER 0.8 MM STANDARD BUILD
4 LAYER 1.6 MM STANDARD BUILD
0.4mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.6mm, 2.0mm, 2.4mm, Please contact us if your board exceeds these.
Cost of four layer PCB is higher than double sided PCB because of complexity of design and higher sensitivity. The better quality of signals, achieved by reducing distortion and propagation levels, is also a factor. Because of the higher levels of signal integrity and reduced interference levels, more manufacturers prefer four layer PCB.
4 Layer PCB Printed Circuit Board,4 Layer PCB,4 Layer PCB Board,4 Layer Printed Circuit Board JingHongYi PCB (HK) Co., Limited , https://www.pcbjhy.com
The reporter noted that Wang Donglei was very optimistic about the performance of related companies when interviewed by the media. But several of the expected sales data he threw were subsequently clarified by the company as "not reaching." Some insiders believe that the current LED market recovery is obvious, but the foundation is not stable and should be treated rationally.
Wang Donglei is overly optimistic?
Wang Donglei was interviewed by the media during the previous Guangzhou International Lighting Exhibition. In the interview, he mentioned that NVC Lighting (02222, HK) can sell more than 6 billion yuan this year. Next year, NVC Lighting and Dehao Runda can add up to 10 billion to 12 billion yuan.
According to the performance report released by NVC in March this year, the company's operating income in 2012 was 3.546 billion yuan, down 6.6% year-on-year.
If this year's sales can exceed 6 billion yuan, it means that NVC Lighting's revenue growth rate will be close to 70% this year. Obviously, this is an explosive growth. However, Dehao Runda said in the announcement: "Based on the current situation, NVC Lighting will not reach sales revenue of 6 billion yuan in 2013."
Dehao Runda also stated in the announcement that the specific sales data of Dehao Runda and NVC Lighting in 2013 and 2014 are currently unpredictable, but according to the current situation, NVC Lighting and Dehao Runda will add up next year. It will not reach the sales revenue level of 10 billion to 12 billion yuan. The specific sales revenue data is based on the data of the company and the regular report that NVC will disclose in the future.
In addition to the performance, Wang Donglei also overestimated the arrival progress of the MOCVD key production equipment of Dehao Runda.
Wang Donglei said that Dehao Runda has now received 92 MOCVD equipments, and all of them have been fully loaded. After the arrival in June this year, there will be about 110 units.
In response to this statement, Dehao Runda said in the announcement that according to the expected arrival schedule of the company's equipment procurement department, the company's MOCVD equipment will not reach the scale of 110 units by the end of June 2013. When the specific scale is reached, the company stated that “the specific order and arrival time of MOCVD equipment will be studied and determined according to market conditions.â€
Rationally look at market recovery
A related person from Dehao Runda said in an interview with reporters that Wang Donglei is more optimistic about the future of the company as a whole. Making this speculation must have his consideration and objective basis, but the future is uncertain.
The above-mentioned people said that income will involve performance. When people see income, they will think about how much performance will be. However, for listed companies, the regulatory requirements are very strict and they are afraid of misleading others.
In an interview with reporters, Zhang Xiaofei, director of the High-tech LED Research Institute, believes that after years of accumulation, LEDs have indeed seen blowouts in the field of commercial lighting. The prices of products are declining, channel distribution is positive, and end consumers are beginning to accept. .
In the context of confidence, the stock prices of many LED listed companies such as Dehao Runda have been rising all the time, and individual stocks have almost doubled.
However, Zhang Xiaofei reminded that the hot business is only commercial lighting, and the huge home lighting market has not yet started. He is worried that if it is too optimistic now, it will increase the expansion of production capacity. Once the terminal is unable to digest and cause slow sales, some enterprises will suffer losses.
( This article is reproduced on the Internet. The texts and opinions expressed in this article have not been confirmed by this site, nor do they represent the position of Gaogong LED . Readers need to verify the relevant content by themselves. ) 
What is 4 layer PCB?
Compared with Double Sided PCB , multi-layer PCB have many advantages. They can be designed more compactly. They can greatly improve noise resistance and make layout easier.
4 layer PCB stackup and thickness
4-layer PCB has two stacking forms
For the following reasons, this may be a better stack to use a four-layer PCB:
When the high-speed signal changes the reference plane, there should be a nearby path for its return current to move between the two reference planes. Using two horizons, you can do this by connecting two planes directly to a single channel. For grounding and power layers, the connection must be made through capacitors, which usually require two through-holes and one capacitor. This means worse signal integrity and more circuit board occupancy. On the other hand, having a power plane can reduce the voltage drop on the power rail, thereby releasing the space on the signal layer.
PCB Board Thickness
4 layer PCB Prototype
4-layer circuit board prototyping refers to the trial production of Printed Circuit Boards before mass production. It is mainly used for electronic engineers to design circuits and complete PCB Layout, then to carry out small-scale trial production process to the factory, that is, proofing PCB. The production quantity of four-ply proofing generally has no specific boundaries. Generally, engineers call it proofing before product design has not been confirmed and test has been completed.
Notices for proofing of four-layer circuit boards
The precautions for the production of four-layer PCB samples generally include two groups, one is the Engineer group, the other is the PCB Sample manufacturer.
As a group of engineers, the matters needing attention in proofing are as follows:
1. Choose proofing quantity carefully to control cost effectively.
2. Specially confirm device packaging to avoid proofing failure due to packaging errors.
3. Conduct comprehensive electrical inspection to improve the electrical performance of PCB board.
4. Make good signal integrity layout, reduce noise and improve PCB stability.
As a manufacturer of four-layer circuit boards, the precautions are as follows:
1. Check PCB files carefully to avoid data problems.
2. Conduct process approval in an all-round way and process configuration with self-manufacturer.
3. Control production quantity, reduce cost and maintain quality.
4. Communicate with customers who need samples to prevent accidents in advance.
4 layer PCB price and cost
We specialize in Quick Turn PCB services with an industry leading turnaround time as fast as 24 hours. Three low-cost options for a small number of PCB prototyping needs. At the same time, we also provided Flexible PCB , Rigid- Flex PCB , Metal Core PCB , High-TG PCB, Aluminum PCB , PCB Stencils, PCB Assembly Services and so on. Using the same high-tech equipment as our full-service PCB, it can be manufactured quickly and with virtually no limits.
4 layer PCB Manufacturing
We provide a full range of PCB functions to meet all your PCB needs. At present, we accept five PCB file formats (gerber file,.Pcb,.Pcbdoc.cam or.brd file format) for PCB manufacturing. But if you design a circuit board using Sprint-Layout software, you can send the. LAy6 file to us to manually generate the Gerber file.
JingHongyi PCB can provide you with multi-layer PCB board that meets RoHS standard. With laminated material, it can match high temperature in assembly process. It is important to remember that some lead-free assembly processes will require laminated substrates to withstand temperatures exceeding 260 degrees Celsius or 500 degrees Fahrenheit over a longer period of time. To solve this problem, we have high temperature laminates in stock, so that our customers can meet the higher temperature cycle requirements of some lead-free assembly applications.
Min. Order Quantity: 1 pcs
Material: FR-4
Finished Copper: 1oz/2oz/3oz(35μm/70μm/105μm)
Inner Layer Copper Thickness:1oz/1.5oz(35μm/50μm)
Silkscreen: White, Black, None
Surface Finishing: HASL with lead, HASL lead free, Immersion gold, Hard Gold ,OSP...
Shape: Custom Shape
100% Quality control
When making circuit boards, and after they are finished, we will test and inspect them strictly to ensure that the product reaches 100% eligibility rate. Preferential prices and higher quality have always been our constant pursuit:
Videos for 4 layer PCB design and manufacturing
Dehao Runda issued an announcement to deny the "high" performance
After a one-day suspension, on June 14, Dehao Runda (002005, SZ) issued a clarification announcement on media reports. Interestingly, this clarification announcement has amended or even denied the multiple data and statements made by Wang Haolei, Chairman of Dehao Runda.