High Density Interconnection (HDI) refers to circuit boards with dense lines, layers of height and holes smaller than 0.15mm. HDI is manufactured by adding a layer method and micro blind hole. It usually has 1 order and 2 order arbitrary interconnection.
HDI is often used in mid, high-end consumer electronics and areas with high requirements for boards, such as mobile phones, notebooks, medical devices, military aviation and so on.
When it comes to the origin of HDI boards, we have to mention the United States.
The HDI was born in April 1994 when the PCB industry formed the Interconnection Technology Research institute (ITRI), a cooperative organization that focuses on circuit board manufacturing. Five months later, in September 1994, ITRI began work on a high-density circuit board called the October Project. After about three years of research, ITRI published the October Project phase1 round2 report evaluating micropores on July 15, 1997, officially launching a new era of "high-density interconnect HDI".
Since then, HDI has developed rapidly. In 2001, HDI became the mainstream of mobile phone board and integrated circuit sealing boards.
HDI belongs to high-end circuit board manufacturing, which has a high threshold in terms of equipment, talents and production control. The three basic points for checking the reliability of HDI board factory are as follows:
In terms of equipment, HDI needs new equipment, and the initial investment is very large.
A complete production line of HDI equipment costs millions or even tens of millions of dollars in equipment alone. In addition, for the placement of various advanced equipment, it is necessary to have a clean workshop.
In terms of personnel, HDI production needs to be equipped with several engineers with rich experience. Including laser drilling engineers, HDI pressing engineers, HDI whole process engineers, line engineers, welding resistance engineers, senior engineering R&D personnel, etc. That can be seen that the technical threshold of its production operation is high.
In terms of production control, the HDI board factory needs to have a complete production system, the whole process is not exported, and the product quality is strictly controlled.
As mentioned above, HDI has a high threshold for manufacturing, but it is strange that many PCB factories can accept HDI production orders, regardless of the size of the PCB factory.
In fact, all the PCB factories can accept HDI boards orders. But most of the manufacturing process is sent out to other factories, So the quality and delivery time are out of control, and the price is very high to ensure that HDI orders have enough profit margin. But the price is not the most important, the fatal problem caused by process outsourcing is the quality problem. Once the HDI has quality problems, the loss is very huge.
Therefore, in order to reduce the export and reduce the risk of quality problems, some factories choose to make their own PTH. However, this gives rise to another new problem - the copper thickness of hole is thin, and even the no copper phenomenon. As shown below:
At 100 times magnification, comparison of copper thickness at the thinnest part of hole wall of the three PCB factories:
Plate factory A: 14.23μm
Plate plant B: 8μm
The thickness of the copper hole is one of the important factors affecting the reliability and life of PCB. When the copper hole is too thin, it may be pulled off when the through hole is applied at high temperature or high current, resulting in the failure of the board.
Deep cultivation circuit board manufacturing for over 15 years, HDI has its own complete system, the whole process is not sent out, all quality acceptance standards have been used IPC2 standards, such as the thickness of copper hole ≧20μm. NextPCB has its own Mitsubishi laser laser, with the most advanced hole filling line, as well as the most advanced VCP horizontal plating line, resin plug line. Always insist not to send out, to ensure that all PCB is qualified and controlled.
In order to further ensure high reliability, NextPCB brings together hundreds of top technical professionals, who have rich experience in the PCB industry.
High quality is the most basic. Based on the original intention of "reducing cost and improving efficiency for the electronics industry", NextPCB hopes to reduce cost and improve efficiency for users on the basis of ensuring quality.