Zulki's PCB Nuggets

December 09, 2021

Zulki's PCB Nuggets: Cleanliness is Next to Reliability

Today’s PCBs are highly populated with increasingly smaller device packaging. As a result, these advanced device packages are extremely difficult to clean due to tight densities and configurations, especially with bottom terminated components. Current OEM system designs and those on the drawing board are driving these newer technologies, which are the foundation of advanced PCB assembly and manufacturing.

---

October 20, 2021

Zulki’s PCB Nuggets: Thermal Compression Bonding for Extra Fine Pitch Flip Chips

Medical OEMs and others moving toward developing and producing small, portable products may want to investigate the emerging technology of thermal compression bonding or TCB. TCB is ideally suited for miniature products that use fine pitch flip chip devices undergoing PCB microelectronics assembly.

---

September 15, 2021

Zulki’s PCB Nuggets: WBAN Steps Into PCB Microelectronics Assembly

A new miniature wireless network is stepping out of academic journals, into micro-miniature medical device applications, and subsequently onto the PCB microelectronics assembly floor.

---

August 11, 2021

Zulki’s PCB Nuggets: Photonics Comes to PCB Microelectronics Assembly

Photonics has been around for many years. Today, that technology is beginning to make its presence known in PCB microelectronics assembly and in a variety of new applications. But we need to step back a bit and revisit reasons why photonics is so vital to meet today’s demands for increasingly higher speeds in advanced systems.

---

July 14, 2021

Zulki’s PCB Nuggets: Sub-Micron Die Bonding—Don’t Be Misled by Five Micron Placement Standard

It is critical for an EMS company or microelectronics service provider to have the capabilities to design, define, implement, and assemble sensor, biosensor, and MEMS device placement with sub-micron accuracy. Not only should they be able to do that with high accuracy, but also, they should be able to quantitatively verify that accuracy.

---

June 09, 2021

Zulki’s PCB Nuggets: Meet the New Player in PCB Microelectronics Assembly—Interposers

Today, everything is shrinking and getting smaller, as I have written about in earlier columns. Now, a new player is coming in to help make PCB real estate more available on small flex and flex-rigid circuits undergoing microelectronics assembly. That new entrant is an interposer, which is a type of connector that takes connections from one side of the substrate or board or material to the other side.

---

May 05, 2021

Zulki’s PCB Nuggets: How Effective Is Your PCB Microelectronics Assembly?

There is a good chance that all PCB microelectronics assembly and manufacturing processes are not created equal. In today’s day and age, that can be a major issue for medical OEMs who are now in the midst of developing or producing their newly advanced miniature medical products.

---

April 06, 2021

Zulki’s PCB Nuggets: Five Key Benefits for Onshoring PCB Microelectronics Assembly

There are five key benefits to U. S. OEMs for onshoring PCB microelectronics assembly and manufacturing, but this discussion is prefaced by this fact: the future lies in PCB microelectronics assemblies compared to traditional SMT assemblies.

---

March 04, 2021

Zulki's PCB Nuggets: Onshoring for PCB Microelectronics Production?

Many OEMs may not be aware that here in the U. S., microelectronics assembly and manufacturing is leading in technology advances and provides OEMs a relatively easier way to bring that production back to the U. S. compared to on shoring PCB SMT production.

---

January 27, 2021

Zulki's PCB Nuggets: Take a Deep Dive Into U.S. Medical Device Production

There are new angles, new thinking emerging for medical OEMs to consider in order to keep production in the U. S. versus overseas. The foremost thinking (biggest challenge) associated with those angles focuses on whether the product can be produced cost effectively in a timely fashion, so it’s distributed in the supply chain for a given medical device OEM.

---

January 06, 2021

Zulki’s PCB Nuggets: Is U.S. Production Ready for Advanced Medical Devices?

Medical electronics OEMs may be able to move forward with their prototypes into pilot, medium, and high runs right here on American soil. And it may be sooner than later due in large part to the advances in PCB microelectronics assembly, and perhaps, a helping hand from the U.S. government.

---

December 09, 2020

Zulki’s PCB Nuggets: Wire Bonding and CoB for PCB Microelectronics Assembly

Real estate continues to be a precious commodity for substrates, package sizes, dies, and PCBs. But now, the industry is taking another stab at further reducing PCB real estate. Zulki Khan examines wire bonding and chip on board (CoB) to point out what might be best for your medical electronics device while undergoing PCB microelectronics assembly.

---

November 11, 2020

Zulki’s PCB Nuggets: Consider Low-Temp Solder for PCB Microelectronics Assembly

With newer, smaller devices coming on the market, EMS providers and contract manufacturers (CMs) must adjust their PCB assembly technologies to comply with these demands. Zulki Khan details how thermal profiling and the use of the correct solder paste become an even more critical step than before in conventional SMT and the newer microelectronics assembly.

---

October 21, 2020

Zulki’s PCB Nuggets: What’s Different Between C2 and C4 for PCB Microelectronics Assembly?

In Zulki Khan's last column he talked about flip-chip ball grid array (BGA), or FCBGA, making its grand entrance into PCB microelectronics assembly. But that subject requires a lot more digging to get the full story for OEMs planning highly advanced products that demand PCB microelectronics assembly. In that regard, C4 and C2 bumps for flip-chip assemblies are among the top techniques that require close attention.

---

September 09, 2020

Zulki’s PCB Nuggets: FCBGA Packaging Enters PCB Microelectronics Assembly

The demand for smaller circuitry and packaging, as well as ever-shrinking PCB real estate, have continually pushed PCB assembly and manufacturing protocols. Part of these technological advances involves a combination of flip-chip and BGA (FCBGA) packaging. Zulki Khan explains the importance of FCBGAs.

---

August 05, 2020

Zulki’s PCB Nuggets: DOEs on Call for New Wearable Medical Devices

Zulki Khan explores how biosensors for human-machine interfaces (HMIs) and new, flexible electrodes are leading the way, are among the most recent developments and promise more sophisticated medical wearable devices for health monitoring.

---

July 08, 2020

Zulki’s PCB Nuggets: Soft Electronics Pose PCB Microelectronics Assembly Challenges

Zulki Khan explains how PCBs have moved from traditional large rigid boards to considerably smaller rigid and combinations of rigid and flex circuit boards, even to the point that bare chips and wire bonding are used during the PCB microelectronics assembly of these tiny boards.

---

June 24, 2020

Zulki’s PCB Nuggets: Medical Miniaturization and PCB Microelectronics Assembly

Medical electronics continue to be a gamechanger, with miniaturization being foremost today in the minds of medical OEMs. Zulki Khan discusses how there is a growing demand for even greater device and component miniaturization that plays a major role in the PCB microelectronics assembly of these medical devices today.

---

May 13, 2020

Zulki’s PCB Nuggets: Add Hi-rel to ISO 13485 for More Robust Ventilator PCBs

It's important to meet FDA and ISO 13485 standard quality and reliability requirements for ventilators and other medical equipment. Zulki Khan explains how there’s still more that ventilator OEMs need to put into practice, specifically in the high-reliability or “high-rel” area to further add to ISO 13485.

---

April 15, 2020

Zulki’s PCB Nuggets: Urgent Call for Ventilators—PCB Technology at the Ready

An urgent call is out to medical equipment makers that thousands—even millions—of ventilators are in the greatest demand in our history due to the worldwide COVID-19 outbreak. Zulki Khan explains how new ventilator makers—as well as traditional ones—must weigh a number of key PCB design, assembly, and manufacturing factors.

---

March 11, 2020

Zulki’s PCB Nuggets: Putting the Heat on for Thermal Profiling

A unique thermal profile is designed for each PCB job undergoing conventional SMT assembly, as virtually every PCB assembly professional knows. But what about a PCB assembly project involving both conventional rigid board and an extraordinarily small rigid or rigid-flex circuit undergoing microelectronics assembly? Zulki Khan covers PCB hybrid assembly, which requires two separate, unique, and distinctly different thermal profiles.

---

February 12, 2020

Zulki’s PCB Nuggets: 7 Steps to Successful Assembly for Medical Devices Using Microelectronics

Seven major steps need to be taken to achieve successful SMT and microelectronics assembly for medical electronic devices. Zulki Khan explains how these key steps take on special significance for newly emerging implantable and ingestible medical devices and result in medical devices that are robust, smaller, highly reliable, more powerful, and lighter.

---

January 15, 2020

Zulki’s PCB Nuggets: Successful PCB Microelectronics Assembly

In addition to coverage of PCB microelectronics subjects, Zulki Khan addresses one of the most crucial areas: PCB fabrication that creates the circuit board undergoing microelectronics assembly. The burning question is, “Why is fabrication vitally important when it comes to successful microelectronics assembly?”

---

December 04, 2019

Zulki’s PCB Nuggets: Vital Details for Implantable Medical Devices

In addition to smart pills and smart cameras, which Zulki Khan covered in a previous column, another segment of the medical electronics devices market is rapidly growing, as well: implantable medical devices, which medical personnel surgically or otherwise insert into various parts of the human body. Zulki explains the extra measures required for these devices.

---

November 07, 2019

Zulki's PCB Nuggets: Multi-tier Wire Bonding—Diving Into PCB Microelectronics

As the name implies, multi-tier wire bonding involves several levels of wire bonding beyond the single level of wire bonding, which is traditionally used in semiconductor and/or PCB microelectronics assembly. Here, you have two, three, and four levels of wire bonding, in some cases, called stacked wire bonding. Also, multi-tier wire bonding offers OEMs a solution when the number of inputs/outputs (I/Os) are far beyond the traditional ones that are used in the single wire-bonding application.

---

October 23, 2019

Zulki’s PCB Nuggets: Smart Pills & Cameras—The Next Frontier for PCB Microelectronics

"Take two aspirin and call me in the morning," is the proverbial, jovial, and often-cited elixir that doctors have prescribed over the years for whatever ails you. Today, medical electronics are adopting the same concept but with new technologies. Now, the phrase, "Take two aspirin," takes on new meaning, as medical electronics move into new frontiers of inspecting a human’s gastrointestinal tract with new, revolutionary ingestible smart pills and "pill cams."

---

September 25, 2019

Zulki's PCB Nuggets: A Better Grasp of Glob Top Epoxy Factors

In my last column, I cited important aspects of glob top epoxies, calling attention to the fact there are different epoxy manufacturers. In this column, I will continue to emphasize six other important factors of glob top epoxies.

---

September 12, 2019

Zulki’s PCB Nuggets: Get a Handle on Glob Top Epoxies

Most often, glob top is the prevalent method EMS providers use today. However, the most important point to be made about glob top is the fact that multiple manufacturers are producing different glob top epoxies. And within each manufacturer, there are numerous types of epoxies being produced. Another key point is that EMS providers and contract manufacturers generally are the ones deciding on the kind of epoxy to use. This column will further describe how you can get a handle on glob top epoxies.

---

July 31, 2019

Zulki’s PCB Nuggets: Protect the Die and Wire Bonding for Effective PCB Microelectronics Assembly

Protecting bare dies on a PCB or substrate is a major process of microelectronics assembly. As we’ve said before, microelectronics assembly and manufacturing work in tandem with traditional SMT manufacturing for complete PCB hybrid manufacturing of today’s smaller form factor products, including IoT, wearables, and portable devices.

---

July 18, 2019

Zulki’s PCB Nuggets: PCB Microelectronics—Inspection and Calibration

Microelectronics manufacturing is the companion of SMT manufacturing and forms PCB hybrid manufacturing. Tools for SMT manufacturing have been around for a long time and have proven their value. Now, with microelectronics, new and different types of high-powered laser microscopes are populating the microelectronics assembly and manufacturing area to provide highly effective inspection and calibration.

---

June 27, 2019

Zulki’s PCB Nuggets: Three Die Attach Methods for Microelectronics Manufacturing

Die attach technology is increasingly being applied in PCB hybrid manufacturing (i.e., combining traditional SMT manufacturing with microelectronics) to comply with the requirements of small PCBs, especially rigid, flex, and combination rigid-flex circuit boards. These smaller boards are used in a variety of IoT, wearable, and portable applications.

---

June 12, 2019

Zulki’s PCB Nuggets: Consider the Integrity of Wire Bonding

While reliability and integrity can be regarded as synonymous as far as PCB manufacturing with microelectronics assemblies is concerned, the integrity of wire bonding—the methodology of interconnecting the wire to the bond pad—takes on other reliability-associated process qualities. Here are three factors that need to be implemented to create the integrity of wire bonding.

---

May 30, 2019

Zulki’s PCB Nuggets: Avoid PCB Wire-bond Loop Failures

Today, hybrid PCB manufacturing is making greater inroads into our industry, which is the marriage of traditional SMT manufacturing together with microelectronics and wire bonding. In many cases, the OEM working with EMS providers doesn’t fully understand the nuances of effective wire bonding and related failures.

---

May 15, 2019

PCB Hybrid Manufacturing: Coming Your Way

Today, PCB manufacturing is rapidly evolving to include SMT as well as microelectronics, such as chip-on-board (CoB) installation, flip-chip assembly, wire bonding, and die attach. SMT merged with microelectronics is also known as hybrid manufacturing. This is occurring because PCBs have begun shrinking at a faster pace in recent years due to the introduction of wearables, IoT devices, and portables demanding smaller circuit boards.

---

May 13, 2014

Zulki's PCB Nuggets: Tighter Scrutiny Needed for PCB Cleaning Agents

PCB cleanliness on the assembly floor is now getting more attention, due to tiny residues and contaminants being left on assemblies after new, advanced assembly processes. Cleaning methodologies, testing, analysis, and special chemistries are being taken to a new level to assure customers of ultraclean boards to avoid costly latent issues.

---

March 12, 2014

Zulki's PCB Nuggets: Uncovering Assembly Problems of High-Speed PCBs

The high-speed board may be perfect when it comes to BGA assembly. All the balls properly collapse; all the thermal profiles are accurately determined and performed. All soak temperatures, pre-heat, soak, and cool-off periods fall within manufacturer limits and ranges. Yet, this high-speed board fails at high speed at the time of system functional level testing in the system.

---

January 14, 2014

Zulki's PCB Nuggets: EMS Discovers Mature IC Technologies

Columnist Zulki Khan asks, "Did you know that really new, up-to-the-moment PCB technologies are nesting on the doorstep of PCB assemblers?" In fact, he says some of these technologies are very mature, but they're completely new to the assembly side of things.

---

November 13, 2013

Zulki's PCB Nuggets: Another Look at AOI

PCB inspection is taking on greater significance as boards and packaging become increasingly smaller, with greater functionality. Automated optical inspection (AOI) and its backup associate, X-ray, team up to catch a variety of board assembly problems. But it's AOI that's at the forefront of this process.

---

September 11, 2013

Zulki's PCB Nuggets: ECOs Reviewed - The Importance of Accuracy

Designers can perfectly layout a design and, in theory, follow written specifications to the letter, but when one factors in the practicality of that design, virtually everything associated with it has its limitations--ranging from the material used to make the board to assembly, machine tolerances, and process limitations.

---

November 13, 2013

Another Look at AOI

PCB inspection is taking on greater significance as boards and packaging become increasingly smaller, with greater functionality. Automated optical inspection (AOI) and its backup associate, X-ray, team up to catch a variety of board assembly problems. But it's AOI that's at the forefront of this process.

---

January 14, 2014

EMS Discovers Mature IC Technologies

Columnist Zulki Khan asks, "Did you know that really new, up-to-the-moment PCB technologies are nesting on the doorstep of PCB assemblers?" In fact, he says some of these technologies are very mature, but they're completely new to the assembly side of things.

---

March 12, 2014

Uncovering Assembly Problems of High-Speed PCBs

The high-speed board may be perfect when it comes to BGA assembly. All the balls properly collapse; all the thermal profiles are accurately determined and performed. All soak temperatures, pre-heat, soak, and cool-off periods fall within manufacturer limits and ranges. Yet, this high-speed board fails at high speed at the time of system functional level testing in the system.

---

May 13, 2014

Tighter Scrutiny Needed for PCB Cleaning Agents

PCB cleanliness on the assembly floor is now getting more attention, due to tiny residues and contaminants being left on assemblies after new, advanced assembly processes. Cleaning methodologies, testing, analysis, and special chemistries are being taken to a new level to assure customers of ultraclean boards to avoid costly latent issues.

---