Tuesday, November 17, 2020

PCB Manufacturing Process - How To Provide The Best Products

 Are you prefer good quality PCB? Then this might be your long awaited article. We are going to guide you through the necessary steps you need to make the difference to make you achieve the best.

1、PCB Manufacturing Process

In a broad sense, As we all know, All PCBs have a distinct use for an electric product,  there is no standard,  therefore the procedures involved in the production of the PCBs varies and more complex.

In the manufacturing of the PCBs, there are several steps should be followed to achieve the desired result. 

well PCB

Step 1: The first thing that comes to mind is deciding what kind of electronic circuit to design on the printed circuit board. It is an essential aspect of PCB manufacturing. Make your preferred designs for your board with software like EAGLE.
Step 2: Print out your design on a suitable type of paper using a printer - laser printer. Ensure that it is possible to fit in all the components on the print, with the size of the layout equivalent to that of the PCB.Cutting and laminating according to the size of the finished board or the size of the panel; And then drying, it is to remove the moisture in the board and prevent it from warping during processing. Generally, it is dried at 150℃ for 3-4 hours.
Step 3: Inner Layer Imaging , Etching and Inner Layer AOI-Photo-imaging is the main process of open and short circuit. Therefore, the environmental sanitation requirements are very high. Personnel entering must be cleaned by air shower door. All operators need to wear anti-static clothing.Through the etching line, the copper skin covered by the dry film is protected, while the copper skin not protected by the dry film is etched away.

For AOI, this is an automatic optical inspection to check whether the core plate after etching has open or short circuit, and the etching is clean or not.The line pattern that needs to be retained at this time will be displayed by etching.
Step 4: the next step is drilling the laminated plate. At this time, there is no metal in the hole, that is, the layer cannot be connected to the layer. In other instances, automated drilling machines are utilized for big sized projects. The surface of the material is coated with gold, nickel, and so on.
Step 5: Next is Outer Layer Imaging and etching- By etching the line, the exposed copper will be etched away, while the copper protected by tin will remain.

Step 6: Surface Finishing Process-Soldermask , silkscreen and some special surface finishing process will be done. 

So far, the board production has been basically completed, but another important thing is to conduct electrical testing to ensure functionality. The main tests that are performed are the circuit continuity and isolation tests. It is then tested and assembled.

PCB technology continues to evolve with the times. There has been a significant improvement in aspects relating to miniaturizing, sophisticating and high-end. The PCB now has successfully been able to meet a wide variety of needs or requirements. 

The manufacturing of PCB depends on some techniques that go along with plating, etching, use of the machine, and so on. When we make mention of these different techniques, you would understand that each of them has its unique functions, and one important thing to note in the manufacturing of PCB is the accuracy of the equipment.

3、Best Manufacturing Process PCB Fabrication Specification
Printed circuit boards are important for every product related to electronics, just as the heart is important to the body. 

The PCBs are concerned with parts or components that give internal instructions to your products, and they are designed in many different shapes and size.
The fabrication specification can be said to be the design requirement which is not concerned with the behaviours or function of a product, but rather, determines the manufacture’s ability, cost, and so on. 

3.1: What to note about the fabrication specification
Size: It refers to the dimensions of the circuit board. At this stage, you need to note that the cost of the printed circuit board varies with the size of the board size and shape. If we should compare an irregularly shaped board to a small rectangular type of the exact board, the irregularly shaped PCB will be more costly.

Complexity: The number of layers and circuit design measures the complexity of the PCB.
Type of material: Many PCB designers prefer the FR-4 as the first option, but considering the thickness of the material, must give the greatest attention. Other types include aluminum boards, Rogers, etc., prices are also different.
Thickness: To some extent, the thickness of the board depends on the number of layers or requirements the designer has designed, sometimes affecting the final thickness.

The thickness of the board is an elementary mechanical specification of the board, and sometimes, 1.6mm seems to be the standard. The designer is responsible for selecting the dimensions that will suit the preferred thickness.

Plating: the plating refers to the situation in which copper surfaces which are not covered are covered with another material of metal to increase the level of solderability when assembly operation completed. Hot Air Solder Leveling is a common type of plating, and we also have other types of plating which include ENIG (Electroless nickel immersion gold is more costly plating but of course gives a better result).
3.2: Checking For Design Rule Violations
Immediately you know your way around fabrication specifications, it is necessary to go along with the specification all through the development process.

If we are responsible for your PCB, then this only means that you prefer a high-quality type, as this is what we offer. We have taken you through the information concerned with the PCB manufacturing processes, and the least we can now do is give you the very satisfied service and your desired products.
Why don't you contact us today and secure your interest in high-quality products?  Also, you can request for a quotation, and in case you have troubling questions or suggestions, please feel free to pass them across.

Friday, November 06, 2020

Converter DC to DC 12VDC to 65-90VDC CT for Audio Amplifier OCP Ver

Converter DC to DC 12VDC to 65-90VDC CT for Audio Amplifier 

Converter DC to DC 12VDC to 65-90VDC CT for Audio Amplifier

This version includes OCP (Over Current Protection) you can download the Gerber for converter board and PWM Board. Gerber, Bill of Materials, CPL File ( Pick and Place File) for order SMT Assembly.

Schematic Board

Converter DC to DC 12VDC to 65-90VDC CT for Audio Amplifier


PCB layout Gerber Board Converter

PCB Layout Gerber PWM Board

BoM PWM Board


Monday, October 26, 2020

Build Stereo Power Amplifier TDA7294 2x90W

Schematic diagram of a Power Amplifier TDA7294

Build Stereo Power Amplifier TDA7294 2x90W

Symmetrical Power Supply

Build Stereo Power Amplifier TDA7294 2x90W

TDA7294 Features:  A very high voltage operating range (± 40V), DMOS power stage, High power output (up to 90W), Mute / STAND-BY function, Low distortion, Low noise, Short circuit protection, Thermal shutdown

PCB Layout Design

PCB Layout TDA7294
Connection Diagram
Diagram TDA7294

Part's list

2 Integrated circuit TDA7294

1 Diode Bridge 10 amps

1 Diode 1N4148

2 short fuse holder for printing and two 5 Amp fuses

2 small 3-pin connectors (GP)

2 large 6-pin connectors (Molex)

1 Transformer 29 x 29 volts AC at 5 or 6 amps.

1 aluminum heatsink

2 mica insulators, with their respective wall passes

2 screws with nut and washer

2 Capacitors 4700 uF at 50V or 6800 at 50V

2 Capacitors 0.1 uF (104) to 100V Polyester

2 Capacitors 0.47 uF (474) at 100V Polyester

2 Capacitors 0.1 uF (104) to 250V Polyester

5 Capacitors from 22 uF to 50V

1 Capacitors from 10 uF to 50V

2 Capacitors from 10 pF to 50V Ceramic

2 Capacitors 390 pF at 50V Ceramic

4 Resistors from 56K to 1 / 4W (green, blue, orange)

2 1K to 1 / 4W resistors (brown, black, red)

6 Resistors from 5.1K to 1 / 4W (green, brown, red)

3 Resistors from 8.2K to 1 / 4W (gray, red, red)

2 2.7 Ohm resistors at 1W (red, purple, gold)

2 Resistors of 8.2 Ohms at 1W (gray, red, gold)

The coil is made with copper wire, 18 gauge according to the AWG table, (1,024 mm.) And a 3/8 bit, on which we make 11 turns evenly, we cut the excess wire and straighten bobbin legs so that there are 10 turns.


PCB Layout TDA7294 Stereo Amplifier PDF

LM4700 Gainclone Amplifier

In this post, Elcircuit will share the amplifier scheme and PCB layout and video tested by Barlex Respectaizer.
LM4700 Gainclone Amplifier

Schematic LM4700 Gainclone Amplifier
Schematic LM4700 Gainclone Amplifier
PCB Layout LM4700 Gainclone Amplifier
PCB Layout LM4700 Gainclone Amplifier

Video Tested:

Download PCB Layout, Schematic, Part List here

Monday, September 14, 2020


12V Subwoofer amplifier

Hello friends, in this post I will make an amplifier kit, using the TDA8954TH class-d amplifier chip that I have previously made, but in this post, I will make a complete amplifier with a subwoofer preamp and also a DC to DC converter circuit, where is the power This amplifier can be supplied using a 12VDC voltage or using a battery, or a 12V battery. The purpose of which is applied to car audio such as monoblock car amplifiers, but this amplifier is also multifunctional, can be used for home audio, the output can be flat, or stereo.

The following is the circuit of the TDA8954 power amplifier along with the converter and subwoofer preamp. 

Downloadable schematic .PDF 

The DC to DC converter circuit, the PWM IC uses TL494, the mosfet uses 6 N-channel Mosfets. For the transformer can use ferrite EE or Toroid. with the number of turns as shown. The primary wire size must be larger than the secondary by a 3: 1 ratio.

12VDC CT for opamp circuit or subwoofer preamp. and this 5V to supply to pin MODE TDA8954.

Then I took the protection from the diagnostic output of TDA8954. so when the amplifier has a problem, the diagnostic pin will send a command to the protection section to turn off the PWM converter for 100mS and will activate again when the amplifier is normal, and this is not in lock mode, except for OVER TEMPERATURE. in case of overheating, the converter will shut off completely until the kit is switched on again and is cool. Over-temperature around 120 degrees Celsius.

I added a series of subwoofer filter circuits, it could also be flat, by changing this jumper pin. or it can also be used for stereo, but only for flat if there is a stereo, no a subwoofer. Subwoofer filter especially for BTL. There is also a subwoofer frequency setting, subsonic filter, bass boost, and gain.

The TDA8954TH circuit is still the same as before, but what is different is the LPF part, I use a single core, diameter 3.3cm. The performance of this amplifier is around 420W according to the datasheet, for a load of 8 Ohms in BTL mode, and 4 ohms in stereo mode. For BTL it is not recommended for speakers below 8 Ohm because later it will be easy to Over Current, it can cause the sound to be broken because when the overcurrent amplifier is restarted, it will dive for 100mS and it is sustainable. So adjust the load to a maximum of 8 ohms for BTL.

And I have designed the following PCB, with a double layer path, as usual, this PCB can be downloaded at the link at the end of the Gerber format post, along with the component list files, schematics, and CPL files.


Step-up transformer, I use a ferrite core ee42, with the number of primary turns 5 + 5 turns. secondary 13 + 13 convolution. the secondary voltage is around 32VDC CT. This is for the 5VDC aux, the number of turns 3, and this for the 12VDC CT aux opamp the number of turns 6 + 6 turns.

For the LPF inductor, the amplifier can use an MS13060 core or you can also use a 77071A7 series core with the same outer diameter of about 3.3cm. because this amplifier is BTL or STEREO so it requires two inductors, but I only use a single core with 2 inductor turns, the way it is twisted is made in the same direction, the number of turns using 1mm wire produces an inductance value of around 22uH x 2.

Download Schematic, BoM, PCB Layout Gerber, CPL Files:


Extract file before using

Thursday, August 27, 2020



Hello friends, on this occasion I will share a complete schematic and PCB layout with BOM files and CPL files for the DC to DC 12VDC to 40-90VDC Converter kit which can adjust to the twisted step-up transformer. Here is a DC to DC Converter scheme using IC TL494 with 8 mosfet IRB4110.

For the transformer, you can use the ferrite EE55 transformer which is rolled using an email hook.
For the primer, use a wire with a diameter of 0.8mm, as much as 7 copies, wound 3 + 3 times.
And the secondary uses 3-fold 0.8mm wire wrapped around 22 times for the CT 90VDC voltage.

To make it easier, elcircuit.com provides its PCB Layout which you can download at the end of the post.

DC TO DC COnverter


Monday, July 20, 2020

12V Power Amplifier Subwoofer using TDA7388 IC

Elcircuit will share the scheme along with the PCB layout for the power amplifier subwoofer that operates on a single 12V DC voltage or can use a 12V DC battery. The circuit and PCB layout were designed by Barlex Respectaizer. The following schematic and PCB layout, you can also download it at the end of the post.
12V Subwoofer Power Amplifier
12V Power Subwoofer Amplifier
The circuit use TDA7388 as the power amplifier and it upgradeable to TDA7560. For the Active Lowpass filter, I use a NE5532 IC. I design this project suitable for car subwoofer, motorbikes audio modification event, home, and everything that comes with 12V battery or transformer. The circuit is made as simple as possible with standard through-hole Components that easily found in the store. There are 2 potentiometer settings: -Frequency cross over -Subwoofer Volume It needs single supply 12Volt/10-15A If use with transformer, you may need external bridge diode to make DC voltage.

12Volt Subwoofer Amplifier