Printed circuit boards (PCBs) come in many types distinguished by the number of layers and style of design Some consist of one layer, which is considered the normal type, but with the development of applications, the number of layers has increased, more complex the application more layers are required. As a result of this diversity the technology of every layer interconnect (ELIC) boards which are characterized by a large number of layers while providing a thin and lightweight PCB board, ELIC PCB boards have greatly advanced the capabilities of electronic industries, and have become indispensable in the development of electronic devices They have high capabilities and the ability to provide multi-layer boards with lightweight and small sizes, thus obtaining high performance and reliability.
What is ELIC PCB?
The basic idea of ELIC PCB is to stack several layers, these layers having to communicate and transmit the signal between them without any weakness or interference to the signal, this is done through high-density interconnections, which is why it is sometimes also called any layer HDI for the density of connection it provides, the interconnections are provided by the use of the number of vias in all the stacked layers, which in turn ensures functional connections between all the layers. Thus PCB with several layers is obtained with a thin thickness and light weight.
What Are the Basic Steps for Manufacturing ELIC PCBs?
First, the procedure of manufacturing ELIC PCB starts with the design level of the board, which includes the subsequent:
- Selecting substances for the ELIC PCB, so that the selection is based totally on the design necessities
- Determining the board elements, their sorts, and shapes to ensure the design of the appropriate ports for the elements.
- Stack layout of ELIC PCB, which includes the method of stacking layers and figuring out the locations of vias, is a precise method and the manufacturing system relies upon it to construct a board
Of course, the PCB ELIC design procedure is done using one of the distinct programs for designing PCB boards.
Secondly, after the ELIC PCB design process is completed successfully without any errors signal loss, or signal interference between the layers, a copy of the design is prepared, and based on it the manufacturing process is carried out in several operations.
The Detailed Steps of Manufacturing ELIC PCBs
- Preparing the Inner Layer
places the basic material that represents the core with a layer of copper, which is the conductive material inside the board, those materials for ELIC PCB board conductive materials include copper, Aluminium, and silver, copper is the maximum commonplace and extensively used.
- Drilling Microvias
The manner of drilling vias, which represent the bridges of connection between the layers of the board, is carried out on the copper layer, that is the conductive layer via the laser drill method as is common and then these holes are packed with copper to make certain that there may be no dimpling or voiding. This step is important to create the PCB ELIC. Also, there’s every other form of vias, blind and buried vias in the ELIC PCB that provide a connection among precise layers without the connection being comprehensive to all layers of the board, thus supplying dense routing. The vias in widespread provide a significant extension within the density of components and ensure the integrity of the connection between layers with no interference.
- Insulating Layer Preparation
The insulation layer offers an insulating area between the conductive layers, accordingly ensuring extra unique routing, making it easier to accommodate a bigger number of layers without disturbing the size or weight of the ELIC PCB board, very thin layers, basically fabricated from FR4—which is the most common—but also polyamide and Rogers; they’re determined earlier at the layout degree, based on the requirements of the utility.
- Layers Stackup
In this step every layer of the ELIC PCB board is ready, and the layer-stacking procedure initiates and is carried on sequentially. This initiates with setting the copper layer, then microvias are drilled, filling in of the holes is completed and the alignment is made, the next is the insulation layer, vais making, and filling. This is repeated a few instances, depending on what number of layers are to be stacked, whose final variety is fixed in advance, given the software requirements, Usually the number of layers can range from 2, 8, 12 to 16, or even up to 30. More complex applications need more layers.
- Stack Alignment
After the stacking process is done one by one, the vias on the layers must be aligned, and any copper which is sticking out of the holes and is unwanted has to be removed. After that, set for lamination and pressing.
- Testing Process
The operator performs comprehensive tests of the board in terms of optical tests or signal analysis and integrity of its transmission, the vias are also checked and the reliability of the laser drill system is ensured with no defects.
Key Considerations to ELIC PCB Manufacturing Process
- The appropriate dimensions of the vias must be determined to ensure higher performance efficiency.
- Ensure that all the vias in the ELIC PCB that have been drilled are filled to ensure that there is no dimpling/voiding of the holes
- When filling the vias with copper, care must be taken to ensure that the copper thickness of ELIC PCB is the required thickness to avoid any defect in the bonding process between the layers and that it does not exceed so that the filling of the vias is equal to the surface of the layer.
- Ensure that the layers are stacked compactly and symmetrically to avoid any functional failure in the board.
Conclusion
The ELIC PCB manufacturing process is very precise so, it may take some time and money. If you want to manufacture an every layer interconnect you must have sufficient experience, especially in the process of drilling holes that provide conductivity to all parts of the board therefore, great care has to be taken when drilling vias for each layer. The importance of the manufacturing of ELIC PCB boards is that it may be expensive, more so in the drilling process; therefore, the designer must have good experience so that his lack of experience does not lead to a waste of money and time. Or you should consider cooperating with a company with good experience and equipment to manufacture ELIC PCB to avoid any financial losses.
