RIGID.FLEX Sample WE.flextwo
RIGID.FLEX Sample WE.flextwo
RIGID.FLEX Sample WE.flextwo
Our RIGID.flex physical sample WE.flextwo shows you the diverse mechatronic possibilities of this PCB technology with internal flex layers. Slot and key elements enable mechanical designs with options for fixing the rigid parts to each other. Non-glued lift-off areas and laser cuts offer a wide range of mechanical options for RIGID.flex technology. The use of microvias for unbundling a BGA with a pitch of 0.4 mm is indicated. The sample also shows an economically clever form of the popular ZIF contact with a layer change in the rigid area and contacts on the outer layer.
Design: Stackup: RIGID.flex FLEX4_1Ri-2F-1Ri
Explanations: The physical PCB sample has a standard stackup 1Ri-2F-1Ri: 4 copper layers with two flex layers on the inside. The range of this technology extends to combinations with HDI technology 6 layers or more (≥ 2Ri-2F-2Ri) using microvias and buried vias, see example on the right 4Ri-2F-4Ri + 3+4b+3. In addition, several flex cores are also possible symmetrically on the inside, unbonded with airgap or as a bonded flex package. The rigid base materials are made of FR-4.1 quality as standard (low halogen, filled, Tg 150°C).
Design: A specially milled outline with slot and key elements on both sides of the flex area
Explanations: The slot and key elements allow the rigid parts to be mechanically fixed to each other. This detachable fixing can make pre-assembly easier. With additional soldering surfaces in the slot and key area, the mated arrangement can also be permanently fixed by solder points.
Design: The rigid outline of the physical PCB sample is milled and includes the slot and key elements. The contours of the flexible areas and the ZIF contact are laser-cut. The flex arms are held in the lift-off areas with micro webs. The micro bars make it possible to separate them by hand without tools and without damaging the flex areas. Thanks to the laser cut, even complex latching hooks are possible without additional effort.
Design: The sample shows an economically clever form of the popular ZIF contact. Coming from the flex area, a layer change takes place in the rigid area and ends in the contacts on the outer layer. The ZIF contact with a thickness of 0.3 mm ± 0.05 mm is formed from the rigid area by a deep milling process. It is designed with a long flexible tail that can be lifted off the rigid part and even moved to the other side. This enables flexible and mechanically decoupled contacting of a ZIF connector in a housing.
Explanations: ZIF = Zero Insertion Force (connector)
Design: Hatched areas show the transition areas in which there must be no vias.
Explanations: One of the most important design parameters in RIGID.flex technology is the distance "G" of vias (PTH) from the rigid-flex transition. The transition area contains both rigid and flexible materials and must not be considered a rigid area and provided with plated holes.
Design:
RIGID.flex can be combined with HDI technology. Microvias are possible from 6 layers with the standard stackups. By changing the stackup, buried vias also become possible.
Laser-drilled microvias, placed directly in the solder pads of a BGA component, allow a pitch of 0.4 mm to be unbundled to three wiring layers. The footprint of such a BGA is shown.
Explanations: Content includes link to https://www.we-online.com/we-flextwo
