Eyeing Fine Pitch

Electronic News, May 8, 2000 by Ken Fleck

Let's look at fine pitch. Microminiature (fine pitch) connectors are those with pin pitch of 1.27mm or below. They include existing connectors widely used in the industry such as: 1.27mm connectors (also called half-pitch connectors since the U.S. equivalent is 0.050 inch), a family that includes 0.050 MODU, Ribcage, Twist Pin, Bristle Brush,Micropax and numerous others; 1.0mm connectors, a family that includes mezzanine card connectors and a host of proprietary designs from such manufacturers as Hirose, Conan, as well as other Japanese and U.S. suppliers; 0.8mm connectors, a family that includes the small form-factor (SFF) PCI, numerous parallel to board and mezzanine connectors, with many proprietary designs from both Japanese and U.S. suppliers.

Other fine pitch connectors are 0.635mm connectors (the U.S. equivalent being 0.025 inch); and 0.5mm connectors, both with many proprietary designs from Japanese and U.S. suppliers.

As demands increase for higher, denser packaging, the industry is responding with development work for pin pitches below 0.5mm. Development of 0.4mm connectors is going forward in Japan. Several proprietary designs are being introduced.

It is generally agreed within the industry that below 0.4mm, the basic contact design prevalent throughout the past five decades can no longer be utilized. This is a sliding contact in which the male is a post and the female is a flexible member (either single beam, dual beam, or frequently in the form of a box configuration). At 0.3mm (U.S. equivalent of 0.012 inch), the sliding contact becomes too fragile as the post would have to be such a thin beam that it would not exhibit required strength.

As a result, the industry has developed z-axis contacts. Z-axis is defined as motion only in the Z plane, not in the X or Y plane. These design types include PHI Gold Dot; Labinal (Cinch) Fuzzbutton; MPI (Metallized Particle Interconnect), developed by Augat (now part of T&B); plated-on contacts to flex or rigid material (of which several manufacturers are engaged in development).

Looking at some specific worldwide numbers for 1999, 1.27mm represented 43.3 percent of all fine pitch connectors (microminiature) demand, followed by 1.0mm accounting for 19.9 percent 0.5mm representing 19.3 percent, and 0.8mm at 11.2 percent. The development work ongoing on 0.4mm accounted for only 2.4 percent of fine pitch connectors in 1999. Below 0.3mm, the market demand was less than 0.1 percent. The growth rates are highest in the very fine pitch designs, notably, 0.5mm and below. Overall demand for fine pitch connectors is projected to increase from $1.055 billion in 1999 to $2.74 billion by 2005, a high compound annual growth rate of 17.2 percent. By 2005, 0.5mm will account for 30.0 percent of all demand, nearly equal to 1.27mm at 30.2 percent. Demand for 0.4mm and below is projected at 10.2 percent by then.

Fleck Research can be contacted at (714) 953-9000 or at fleckresearch.com.