Why hdi technology pcb is popular? 5 Reasons2022-02-04
High-density printed circuit boards
Many years of experience in the hdi technology pcb makes us return to the issues of assessing the complexity and accuracy of manufacturing PCBs for modern electronics. We should keep in mind, first of all, the impact of the evolution of the microelectronic element base at the turn of the 20th–21st centuries on the design.
These are technological versions of switching boards. We are talking here, of course, about the development of functionally complex electronic products and systems. Here integrated circuits of a high and ultra-high degree of integration are widely common as components that implement complex circuit functions.
Creation of hdi technology pcb
At all historical stages of the creation of electronic devices, there was a direct relationship between the:
- degree of integration of semiconductor crystals (chips)
- hybrid integrated circuits (GIS, LSI, VLSI)
- printed circuit boards
- assemblies on boards
- and, ultimately, the entire product
We follow the general obvious trend of miniaturization of hdi technology pcb. This trend expresses in the desire for a denser placement of as many components as possible on both sides of the printed circuit board. The number of component leads is constantly increasing, and their spacing is decreasing.
The art of routing hdi pcb
The art of optimal routing of interconnects in a printed circuit board is to achieve maximum density of their placement. It is to strive to make signal connections as short as possible. Those circuits those are largely responsible for the speed of signal propagation. Therefore for the speed and reliability of the product you need to know hdi technology pcb.
In any case, the length of interconnects by reducing the number of layers in the board and the number of vias (plated holes). Furthermore, it reduces:
- parasitic coupling
- capacitive and inductive losses
- and other negative factors in the transmission of pulsed signals.
The dependence of the complexity of the printed circuit board on the complexity of components and assemblies
Here it is appropriate to recall the quantitative estimates of the degree of integration of electronic components proposed by some foreign experts.
Why a dense layout is important in hdi pcb?
A denser layout using a more complex element base requires more complex printed circuit boa hdi technology pcb. This belongs to the HDI (High Density Interconnections) category. These are complex mobile communication devices, laptops, multi-chip modules, military and space electronics, etc.
With the current state of domestic electronic instrumentation, in most cases, developers have access to the most advanced microcircuits and other elements of microelectronics. These are widely common on the world market in terms of technical level.
Maybe that’s why there is an annoying backlog in the production of printed circuit boards. The developers prefer to order abroad, not so much because of the price, but also because of the insufficient technological equipment of domestic manufacturers. Let’s try to figure this out.
What should be the terms between customer and manufacturer for hdi pcb?
It’s good when the relationship between the customer and the manufacturer regulate by regulatory technical documents. This allows both of them to equally understand what type of product is for manufacturing.
In this regard, the regulatory framework is hopelessly outdated. This defines the requirements for the design parameters of printed circuit boards and specifications for final products. This offers to manufacture, from the most complex boards.
Production of HDI printed circuit boards
HDI printed circuit boards require the use of modern CNC equipment, like any technically sophisticated equipment. Technologies and features of the manufacture of HDI printed circuit boards depend on the methods used in the production process.
hdi technology pcb comesby methods of through metallization and pairwise pressing. In both cases, several blanks are used.
They have the following layers:
Dielectric base: the most common option is fiberglass.
Copper Foil: Provides conductivity to each layer of the PCB.
Galvanic plating: carried out in several stages using photoresist and metal resist.
The complex HDI printed circuit board also has a solder mask and markings. But the procedure for the production of boards of these types is different.
METHODS FOR MANUFACTURING HDI PRINTED CIRCUIT BOARDS
The main feature of the hdi technology pcb in this case is that the holes drill only once, after the creation of internal conductive layers.
It all starts with the application of a conductive pattern. This is a multi-stage process of forming pads using photoresist and metal resist. Then a HDI board forms from the following elements:
outer layer foil;
workpieces with applied conductive pattern;
outer layer foil.
The layers combine in a vacuum hot press, and then cooled in a cold press. After that, through holes are drilled in the almost finished board.
Further, the technology for the production of HDI printed circuit boards implies a metallization stage. Chemical and galvanic hdi technology pcb plating provides electrical conductivity to the holes.
After that, a conductive pattern applies to the outer layers – this is done in the same way as for the inner layers. Only the outer layer is solder masked and finished plating to improve the solder. The product marks according to the scope of application.
Pair pressing hdi technology pcb
Pair pressing allows you to create a special design of HDI boards with vias.
With this method of manufacturing printed circuit boards, the processing of workpieces begins with the drilling of through holes, which provide a connection between adjacent layers. Then, a conductive pattern is applied to each workpiece.
Pressing is carried out in a hot way, and then the board cools in a cold press. After pressing, through holes are drilled in the almost finished board. These are subject to galvanic metallization.
The application of a hdi technology pcb conductive pattern on the outer side of the HDI board is carried out in the same way as for the inner side. This is a multi-stage process of alternating chemical and galvanic copper deposition using photoresist and metal resist.
The final stage is the application of a solder mask and a finishing layer of metallization. The product marks in accordance with the purpose of the product.
BENEFITS OF HDI PCBS
Hdi technology pcb boards chose for the following features:
High density of conductors and components: allows you to reduce the size of the board and the dimensions of the equipment that it completes.
Shortened conductors: work more stable and efficient.
Component heterogeneity: allowed to enhance the best properties of the HDI board.
Stability of work: even under negative influences, the HDI printed circuit board works smoothly.
Increased strength: achieved using modern assembly technologies.