Feb 04, 2010

Association Connecting Electronics Industries announced the December findings from its monthly North American Printed Circuit Board (PCB) Statistical Program.

PCB Industry Growth Rates and Book-to-Bill Ratios Announced
Rigid PCB shipments declined 3.4 percent, but bookings were up 27.3 percent in December 2009 from December 2008. Year to date, rigid PCB shipments were down 23.2 percent and bookings fell by 18.1 percent. Compared to the previous month, rigid PCB shipments increased 13.2 percent and rigid bookings increased 23.3 percent. The book-to-bill ratio for the North American rigid PCB industry in December 2009 registered 1.05.

Flexible circuit shipments in December 2009 went down 0.4 percent and bookings decreased 27.4 percent compared to December 2008. Year to date, flexible circuit shipments were down 1.1 percent and bookings were down 4.9 percent. Compared to the previous month, flexible circuit shipments went up 4.9 percent and flex bookings fell by 2.9 percent. The North American flexible circuit book-to-bill ratio in December 2009 slipped back to 0.95.

For rigid PCBs and flexible circuits combined, industry shipments in December 2009 decreased 3.2 percent from December 2008, and orders booked increased 22.1 percent from December 2008. Year to date, combined industry shipments were down 21.7 percent and bookings were down 17.2 percent. Compared to the previous month, combined industry shipments for December 2009 increased 12.6 percent and bookings went up 21.5 percent. The combined (rigid and flex) industry book-to-bill ratio in December 2009 dipped but remained positive at 1.04.

“Growth rates in both sales and orders continued to improve in the rigid PCB sector in December,” said IPC President Denny McGuirk. “Orders continued to outpace sales, which is keeping the rigid PCB book-to-bill ratio positive. Although the flexible circuit business was lackluster in December, both sectors of the PCB industry in North America showed typical seasonal patterns. The recovery is continuing, but the road back up is proving to be a long one.”

The book-to-bill ratios are calculated by dividing the value of orders booked over the past three months by the value of sales billed during the same period from companies in IPC’s survey sample. A ratio of more than 1.00 suggests that current demand is ahead of supply, which is a positive indicator for sales growth over the next two to six months.

Book-to-bill ratios and growth rates for rigid PCBs and flexible circuits combined are heavily affected by the rigid PCB segment. Rigid PCBs represent an estimated 91 percent of the current PCB industry in North America, according to IPC’s World PCB Production and Laminate Market Report.

The Role of Domestic Production
IPC’s monthly survey of the North American PCB industry tracks bookings and shipments from U.S. and Canadian facilities, which provide indicators of regional demand. These numbers do not measure U.S. and Canadian PCB production. To track regional production trends, however, IPC asks survey participants for the percent of their reported shipments that were produced domestically (i.e., in the USA or Canada). In December 2009, 86 percent of total PCB shipments reported were domestically produced. Domestic production accounted for 86 percent of rigid PCB and 84 percent of flexible circuit shipments in December by IPC survey participants. These numbers are significantly affected by the mix of companies in IPC’s survey sample, which may change slightly in January, but are kept constant through the calendar year.

Bare Circuits Versus Assembly
Flexible circuit sales typically include value-added services such as assembly, in addition to the bare flex circuits. In December, the flexible circuit manufacturers in IPC’s survey sample indicated that bare circuits accounted for approximately 74 percent of their shipment value reported for the month. Assembly and other services make up a large and growing segment of flexible circuit producers’ businesses. This figure is also sensitive to changes in the survey sample, which may occur at the beginning of each calendar year.

Interpreting the Data
Year-on-year and year-to-date growth rates provide the most meaningful view of industry growth. Month-to-month comparisons should be made with caution as they may reflect cyclical effects. Because bookings tend to be more volatile than shipments, changes in the book-to-bill ratios from month to month may not be significant unless a trend of three consecutive months or more is apparent. It is also important to consider changes in bookings and shipments to understand what is driving changes in the book-to-bill ratio.

The information in IPC’s monthly PCB industry statistics is based on data provided by a representative sample of both rigid and flexible PCB manufacturers in the USA and Canada. IPC publishes the PCB Book-to-Bill Ratio and the PCB Statistical Program Report each month. Statistics for the previous month are not available until the last week of the following month.

www.IPC.org

Please visit our home page at: www.pcb-solutions.com We are a supplier of Domestic and off-shore Rigid, Rigid-Flex and Flex Printed Circuit Boards (PCBs), Domestic Military PCBs, Domestic Tier I PCBA, Domestic Sheet Metal, Domestic Injection Molding and other Custom Fabricated Services.

http://www.pcb-solutions.com/pcb.html

http://www.pcb-solutions.com/flex.html

Through the years, the printed wiring board industry has had to evolve in both materials and processes to meet the needs of the world’s electronic challenges. At first the laminate resin systems were inadequate to survive thru multiple thermal excursions of double-sided assembly and rework processes, then the need to meet the high speed signal integrity requirements were needed and now because of the environmentally friendly initiatives of RoHS have again asked the industry to step it up.

Currently most printed wiring boards can meet RoHS (Restriction of Hazardous Materials) directive requirements as long as the boards’ surface finish does not contain lead. Most if not all laminate manufacturers have already removed or reduced mercury, cadmium, hexavalent chromium, polybrominated biphenyls and polybrominated diphenyl ether levels to meet the directive. The challenge has been how to reliably attach components to the PWB without the use of lead, which have higher temperature and longer oven dwell times due to lead free metals being used. For this you need to look at the laminate materials Td rating (Time to Decomposition).

That’s right, even though material Tg has been the main focus of a laminates ability to survive temperature for years, it is not as important as the material’s Td.

Td is the measure of how long a material can handle the higher temperatures of the assembly process. Materials are more thermally resistant as evidenced by their higher Td rating and their ability to achieve a T260 or T288. A T260/288 (Time to Delamination) is the amount of time the material can withstand exposure to 260 / 288°C.

However, if you have a low cost double sided board that requires the use of lead free solder, it may not necessarily mean that you need the higher Tg/Td laminate. Talk to your assembler; you may be spending more than you need to on raw material costs, and being that laminate costs are the single highest material cost of the printed wiring board, it may be worth running some tests by subjecting boards to multiple Pb free reflow cycles to verify it’s resistance to delamination and blistering.

It is true that lead free solder does require higher reflow temperatures and longer dwell times but if the overall density of board is low, it will reflow faster because the entire structure heats up faster and does not require as long of a time in the assembly ovens to get up to the necessary reflow temperature to make a good solder joint, the lower Tg/Td material can reliably withstand the assembly process. Keep in mind that even standard 130dC Tg laminates made today are superior materials that meet RoHS requirements and work well for many different applications and in many cases can take a the thermal excursion of lead free assembly.

On the other hand if you have an expensive multilayer board that has a lot of copper planes, high density, it takes the structure much longer to heat up in order to reflow all the solder joints, in this case you need the extra assurance of high Td rated laminate systems.

If you have questions regarding materials or anything else PCB- Send us an email at info@pcb-solutions.com and we will be happy to guide you in the right direction. For more detailed information on Surface Finishes, visit our Surface Finish presentation in the Tech Zone at http://www.pcb-solutions.com/files/TECHZone-09-02-surface-finish.pdf

Please visit our home page at: www.pcb-solutions.com We are a supplier of Domestic and off-shore Rigid, Rigid-Flex and Flex Printed Circuit Boards (PCBs), Domestic Military PCBs, Domestic Tier I PCBA, Domestic Sheet Metal, Domestic Injection Molding and other Custom Fabricated Services.

http://www.pcb-solutions.com/pcb.html

http://www.pcb-solutions.com/flex.html

Bob Neisis

Quality Manager

PCB Solutions, LLC

bobn@pcb-solutions.com

There is an old saying “Nothing Solders Like Solder” but because of shrinking component footprints, environmental initiatives, cost, reworkability, mixed technology boards, ease of assembly and of course reliability finding the right finish for your product has made the selection of PWB surface finishes a little more complex.

There has been various attempts to solve the many issues, there was high hopes for the many finishes including Organic solderability preservatives, immersion silver, immersion tin, non leaded solder, electroless nickel immersion gold, flash gold, electroless nickel immersion paladium immersion gold however some are not available at all PWB shops, some designs require multiple surface finishes that are not compatible and all of them have there pros and cons.

Other than the tried and true leaded solder, the one surface finish that seems to have lasted the longest and has gained the most acceptance is ENIG (Electroless Nickel Immersion Gold) because it has a long shelf life, a flat surface and is still relatively inexpensive due to the gold’s ultra thin thickness even though gold prices are now reaching all time highs.

The selection of surface finish needs to done with your Electronic Manufacturing Service partner because when assembled boards have solderability issues, they are the ones that have to deal with the domino effect and headaches of costly rework and fleeting schedules.

If your surface finish is the cheapest but often requires assembly rework, the extra cost of a surface finish from the PWB shop is a fraction of the cost when schedules slip, rework starts and blame is in abundant supply.

If you have questions regarding surface finishes or anything else PCB- Send us an email at info@pcb-solutions.com and we will be happy to guide you in the right direction. For more detailed information on Surface Finishes, visit our Surface Finish presentation in the Tech Zone at http://www.pcb-solutions.com/files/TECHZone-09-02-surface-finish.pdf