Surface Mount Technology vs. Workstation Design

In today’s modern SMT assembly facilities, the design and flexibility of the workstation is critical to maintain quality, workflow and ergonomics. Unlike the old, static, welded frame workbenches and workstations of the past that were never moved or reconfigured, the modern workstations now incorporate a modular, flexible, adaptable design, with a wide variety of options,  that allows the end-user tremendous flexibility in reconfiguring the furniture to meet an ever changing production environment.

Circuit board assembly used to be a fully mechanical process with through-hole components relying on bent leads to secure them to the board before manually applying solder.  Component preparation was also a manual or semiautomated process to form, straighten or cut leads to facilitate assembly. Today, fully automated equipment handles most of those same operations, including x-ray inspection and inline circuit inspection.  As a result, the role of the workstation has evolved to accommodate a production staff that is highly trained to perform multiple high level functions, often at the same workstation.  Productivity is more important than ever to maintain a competitive edge over off-shore manufacturers, so the workstation must be designed to adapt and change as production requirements change. No longer is it acceptable to simply scrap that old workstation and start over just because it no longer meets your current needs. A workstation design that permits quick and easy reconfiguration is the only viable option in today’s competitive environment. Carefully researching the workstation systems on the market, while planning for future needs, will result in substantial cost savings over both the short- and long-term while providing considerable ergonomic advantages.

Workstations that are considered “state-of-the-art” can and will provide more than just a worksurface.  Examples of  features should include: ESD protection, height adjustability, easily add casters for mobile applications,  cleanroom certification, Shelving (solid or wire), overhead task lighting, tool and equipment stands, test equipment carts, mobile maintenance stations,  Overhead mounting options for electric tools, LCD monitor arms, tote bin bars, tool trollies, Material transfer technology (ball transfer, conveyors, Flow racking) and rack mount/enclosures must be part of the overall package for continued adaptability in your changing environment.

 

In a typical SMT assembly facility, these modular workstations can be found in a variety of areas, such as: Machine Programming centers, Solder paste / metrology set-up, Post Process assembly of non-wets and odd form components, In-line inspection, box build assembly, Rework & repair, Product packaging, Quality control, Supervisory or management areas.  With a wide variety of module sizes available, nearly any possible configuration can be provided to meet the often limited footprint available in today’s modern assembly facility.

As SMT assembly trends continue to evolve into the age of nano-electronics, how is the job function of  your people and equipment going to change in the future?  Lean manufacturing, as well as state and federal legislation, may also have an effect on the end users requirements for workstation designs of the future.   While we don’t have the answers to those questions yet, we can be certain that workstation manufacturers will be working closely with the SMT industry to insure the designs will change as the industry dictates.

4 Simple Ergonomic Steps to a More Productive Workplace

Workplace ergonomics is getting a lot of attention nationwide in response to a sharp increase in incidents of repetitive strain injuries resulting in musculoskeletal disorders, such as carpal tunnel syndrome. Occupational diseases often mean repeated surgery, intractable pain, inability to work, time off for the affected employee and, ultimately, higher costs for the employer. Listed below are four steps a company can take to address this growing problem:

Step 1:Review tasks for risk factors: The first step to correcting problems is to understand the key workplace ergonomic risk factors and review work tasks in your operation to see which ones apply. This can make a tremendous difference, since occupational safety professionals estimate that reducing physical stresses could eliminate as much as half the serious injuries that happen each year.

Step 2: Control risk factors with engineering and administrative controls and personal equipment where it is effective: engineering controls to improve ergonomic risks may include changing the way parts and materials are transported or changing the process to reduce how workers are exposed to risk factors.

Step 3: Understand how to make the work space work ergonomically. With any task, selecting the proper tool is crucial. The key is to understand the work process and employee’s safety needs involved. After identifying the likely risk factors in an operation, develop a safer work environment by carefully selecting the tools and work stations workers will use.

Step 4K Use work station design principles to improve ergonomics. The following strategies typically yield safe work environments: 1) make the work station adjustable 2) locate materials to reduce twisting 3) avoid static loads and fixed work postures 4) set the work surface to the particular task 5) provide adjustable chairs 6) allow workers to alternate between standing and sitting 7) support the limbs 8) use gravity 9) design for proper movements 10) consider computer monitors 11) provide simple dials and displays 12) consider overall environmental conditions.

Implementing 5S Workplace Organization Methodology Programs in Manufacturing Facilities

Many manufacturing facilities have opted to follow the path towards a “5S” workplace organizational and housekeeping methodology as part of continuous improvement or Lean manufacturing processes.

5S is a system to reduce waste and optimize productivity through maintaining an orderly workplace and using visual cues to achieve more consistent operational results. The term refers to five steps – sort, set in order, shine, standardize, and sustain – that are also sometimes known as the 5 pillars of a visual workplace. 5S programs are usually implemented by small teams working together to get materials closer to operations, right at workers’ fingertips and organized and labeled to facilitate operations with the smallest amount of wasted time and materials.

The 5S system is a good starting point for all improvement efforts aiming to drive out waste from the manufacturing process, and ultimately improve a company’s bottom line by improving products and services, and lowering costs. Many companies are seeking to make operations more efficient, and the concept is especially attractive to older manufacturing facilities looking to improve the bottom line by reducing their costs.

“A place for everything, and everything in its place” is the mantra of the 5S method.  The result is an improved manufacturing process and the lowest overall cost for goods produced.  Implementing the 5S method means cleaning up and organizing the workplace in its existing configuration. It is typically the first lean method that organizations implement. This lean method encourages workers to improve their working conditions and helps them to learn to reduce waste, unplanned downtime, and in-process inventory.
A typical 5S implementation would result in significant reductions in the square footage of space needed for existing operations. It also would result in the organization of tools and materials into labeled and color coded storage locations, as well as “kits” that contain just what is needed to perform a task.

The 5S methodology is a simple and universal approach that works in companies all over the world. It is essentially a support to such other manufacturing improvements as just-in-time (JIT) production, cellular manufacturing, total quality management (TQM), or Six Sigma initiatives, and is also a great contributor to making the workplace a better place to spend time.

Benefits to the company from using the 5S methodology include raising quality, lowering costs, promoting safety, building customer confidence, increasing factory uptime, and lowering repair costs.

Removal of Conformal Coating with Small Sandblasters

Development of conformal coating technology was driven to a large degree by the military and aerospace industries. While conformal coatings are mostly used on populated, printed wiring boards (PWBs), they are also used to protect components such as transistors, diodes, rectifiers, resistors, integrated circuits (ICs) and hybrid circuits including multichip modules (MCMs) and chip-on-board (COB).

Recent environmental regulations and concerns have had a significant impact on both coating materials and application methods, particularly with regard to control of volatile organic compounds and chlorofluorocarbon compounds. VOCs and CFCs have been extensively used as solvent carriers. Manufacturers and suppliers of conformal coating materials have responded by developing non-solvent based coatings and environmentally acceptable methods of application, curing and removal.

It is important to consider how the choice of a conformal coating material affects the rework and repair issues. The need for rework or repair of a conformal coating can occur any time after completion of an assembly due to a variety of process or product requirements and component replacement issues.

A number of methods are available for rework of conformal coatings. These include thermal, chemical, mechanical, plasma and laser-based systems and small sandblasters or “micro abrasive blasters,” which will be the focus of this column.

Micro-abrasive blasters used for conformal coating removal are small sandblasting systems that are commonly used for metal deburring and etching as well as surface preparation. The cutting media is introduced into a compressed air stream and is ejected through a hand piece utilizing tips as small as 0.026″. This is directed at a component or surface area on PCB where the conformal coating has to be removed. This system can remove conformal coating from a single test node, an axial leaded component, a through-hole IC, an SMT component or an entire PCB without any modification to the system for a variety of coating materials. This method provides the most practical and environmentally friendly means for removing conformal coating from PCB assemblies.

Although these small Micro Abrasive Blasters provide the most practical and environmentally friendly means of removal, they also pose a problem. Micro Abrasive Blasters can generate static electricity as the high velocity air and particles impinge on the PWB surface. The ESD voltage generated at the point of contact can cause damage to components and electrical circuits on an assembly.

Equipment manufacturers have used several different approaches to solving the ESD problem. These are: 1) the installation of AC or DC pulsed ionizer bars in the chamber results in a rapid decay of ESD voltages in the work cell and tubing 2) the installation of a point ionizer at the end of the nozzle to dissipate any static charge built-up in the media stream at the point of contact 3) the use of an inline, auto balanced ionizer where the air source is split, one side flowing to the media and the other side flowing to the inline ionizer. This ionized air is then injected into the media stream just before it leaves the nozzle, eliminating the static charge buildup in the media chamber. The ionized air is also pumped into the work chamber. With this type of system, ESD levels are reportedly in the +10V range.

Addressing Ergonomics & Repetitive Motion Injuries in Manufacturing Facilities

In today’s manufacturing environment, ergonomics and repetitive motion injuries are major issues that every business must address to ensure production levels remain at expected levels and employee injuries remain as infrequent as possible.

Although many of the hand assembly processes have been replaced with automated equipment over the past 20 years, there is still a surprising number of manual operations still required for many applications. A good percentage of these manual assembly processes still involve the use of conventional hand tools, such as pliers, screwdrivers, crimping tools, etc. Whenever a manual hand tool is being used to perform a function, repetitive motion injuries may be the result. Taking steps to reduce or eliminate these injuries before they occur is important.

Whenever the application dictates, replacing hand tools with pneumatic or hydraulic tools should be considered. For example, if a technician is cutting leads on a circuit board for 6 to 8 hr. a day using a conventional cutting plier, the fatigue and repetitive motion factor escalates quickly. Replacing that hand cutter with a pneumatic cutter will dramatically reduce those factors. In addition, production levels will improve. The same process holds true for other hand operations such as crimping, pinching, turning fasteners, etc. Now, not all hand operations can be performed efficiently with a pneumatic tool, but whenever possible, making this switch will yield immediate results.

Typically, pneumatic tools can be operated with either a hand-lever control, or remote footswitch control. Most of these tools can also be hand-held or fixtured for hands-free operation. If the operation does not lend itself to the use of a standard, off-the-shelf tool, a custom designed tool can often be provided to meet a specific application.

Jim Norton is president of Custom Products & Services, Inc. (custom-products.com).