HDIs — High Density Interconnect Boards
Now Dangerous hunt HDI boards fast-growing fast technologies in PCBs Epec This can by itself lead some of the blind and/or buried vias, andhas microvias of the HDI Boards. 006 or less in diameter. Circuitry on news is tighter level of board.
HDI stands for High-Density Interconnector Board and is a type of printed circuit board that has a higher routing density than traditional PCBs we have (6 types of HDI boards types surface to surface with through vias, buried vias and through vias, 2 or more HDI layer with through vias, passive substrate without electrical interconnection, coreless construction news pairs of layers or alternative constructions news coreless constructions with pairs of layers.
High Density Interconnect PCB – HDI
Printed Circuit Board (PCB) Based on High-Density Interconnect (HDI)
Consumer Driven Technology
The via-in-pad approach allows more technology on fewer layers — as they say, bigger is not always better. Then came the late 80’s and suddenly video cameras shrank from the size of a novel to the size of your palm! Everything moved to mobile computing, working from home drove technology to make computers faster and lighter to enable the consumer to work from the office or from home or from anywhere.
The main reason for these changes is HDI Technology. More products do more, weigh less, and are smaller in physical size. Small, specialty equipment, miniaturized components, and thinner materials all combine to let electronics keep a small footprint while throwing in the technology, quality, and speed.
Key HDI Benefits
As consumer needs evolve, so must technology. Now developers will always have HDI (high density interconnection) option, place larger volume components down both sides of the raw PCB. Techniques such as multiple via processes (like through hole-in pad and blind via technology) give designers more PCB real estate to pack small components closer together. Smaller geometries result in smaller & thinner components, which drive more I/O. outputs the signal at higher speed making the signal loss and crossing delay negligible.
Via in Pad Process
Synchrony of surface mount technologies in the late 1980’s and beyond is modeled to transcend the limits with BGA’s, COB, and CSP spanning smaller square surface inches. A via in pad process allows for vias to be placed in place in the fab lands. Inside of the via is plated with information, the via is filled with a conductive or non-conductive epoxy, capped and plated over again—making this totally invisible.
Except it still sounds simple and yet on average there are a whole eight other steps in this one-of-a-kind process. Specialty equipment and trained technicians closely monitor the process to achieve the perfect hidden via.
Via Fill Types
Very generalising, there are various types of Via filling material: non conductive epoxy resin, conductive, copper-filled, silver-filled and electro-chemical plating. All of this results in a flat land with a via, which will soldered like normal lands. Vias and microvias are drilled, blind or buried, filled then plated, then hidden beneath SMT lands. Burying vias are difficult to fabricate and takes long time to implement. Ultimately, adding these four drill cycles and drilling to a controlled depth increases process time.
Cost Effective HDI
Whilst we see some consumer products shrink down in size, the consumer thinks the same quality comes with the smaller package second only to cost. The shrink is possible during design with the help of HDI technology from an 8 layer TH PCB to a packed PCB of 4 layer HDI microvia technology. A properly done HDI 4 layer PCB can be an option against a regular 8 layer PCB providing equivalent or higher routing capabilities.
It must be remembered that the microvia process does add to the cost of the HDI PCB, but as long as the design approach and circuit density are correct, the material square inches and circuit layers saved far exceed the incremental cost of the processing within the HDI PCB.
Next you make Up Apron HDI Boards
HDI PCB fabrication requires specialized equipment and processes, such as laser drills, plugging, laser direct imaging and sequential lamination cycles. * HDI boards– thinner lines, tighter pitch and tighter annular ring, thinner specialty material. This allows alternative board, which has higher manufacturing costs, takes more time and requires a significant investment to build this type of board.
Laser Drill Technology
It gets more of the microwave van, drilling the smallest of micro-vias, balancing technology on a board surface. The sub micron via or blind via can then be cut using this 20 microns (1 mil) diameter beam of light, which can cut through metal and glass. New products such as uniform glass materials low loss laminate, low dielectric constant These have actually much higher heat resistance for lead free assembly therefore can use these smaller holes.
HDI Boards Lamination & Materials
Unlike one-layer PCBs, advanced multilayer technology allows additional pairs to be added in total to create a multilayer PCB. Ripple has a unique quad-press process, where the inner layers being used are plated and imaged prior to them getting pressed together, something that is possible because a laser drill is used to hole them. This process of building up more is called sequential build up. SBU fabrication uses solid filled vias which help in better thermal management, stronger interconnect and improved reliability of the board.
Resin coated copper was developed for poor hole quality, higher drill times and thinner PCBs. RCC features ultra-light weight, ultra-low profile and ultra-thin copper foil, which is sunken in with micro sized nodules to the board surface. Thinnest and finest line and spacing technology chemically treated then primed.
In line chemical is used to apply the dry resist to the laminate core in this example. This old technology process was further recommended process that before the lamination process, part material is heated up to desired temperature. Specifically, heating of the material promotes more uniform dry resist application onto the laminate surface, since the material absorbs less heat from the hot rolls (this creates uniform, stabilized exit temperatures with the laminated product). – The constant entry and exit of temperatures traps less air underneath that film, which is important for replicating fine line and spacing.
LDI & Contact Imagery
While its a costly endeavor, the ability to image finer-than-ever lines and process these HDI parts via semiconductor Class 100 Clean rooms is a must. Closely spaced annular rings require tighter controls. With smaller lines, touch up to rework or to repair is practically not possible. 3 Key Phototool Quality, Laminate Prep & Imaging Parameters Process Defect is Determined in the Clean Room Reminder: dry film resist is still the process of choice for ALL tech boards.
Even then production traceability past 1 mil still exists, for example, laser direct imaging (LDI) is a much better solution for these small features, as at this point of the cost of production cycle, contact imaging is still the most common method. An SC100 room with contact imaging is still the workhorse in many factories. And with demand on the rise, laser drilling and laser direct imaging are also all making their way into the picture. In every HDI facility, Epec utilizes cutting-edge technology equipment to produce this advanced PCB.
Cameras, laptops, scanners, cell phones, these devices will still continue to push technology in smaller, lighter consumer daily use requirements. The average mobile phone in 1992 weighed between 220 and 250g and only performed one fucking function — we called people on it; whereas today we call, text, browse the internet, play our favourite music or games and take photos and video on one slim-balanced device of 151g (the latest models)! HDI technology only forms a small part of this epec world, but it is out there and as our culture evolves, HDI technology will continue to be pushed forward and Epec will always be here to scratch that itch for our customers.