X-ray Inspection of Hidden Solder Joints Why Some Joints Cannot Be Seen As packages have moved to area array terminations, the solder joint has moved out of sight. A ball grid array, a chip scale package and a land grid array all connect on the underside of the body, so…

Line Clearance and Setup Verification Changeover Is a Risk Event Changing a line from one product to another is the point where the highest number of avoidable errors enter a factory. Feeder positions are re-loaded, programs are selected, stencils are swapped and the first boards of the new product are…

Solder Paste Storage, Thawing and Working Life Paste Is a Chemical Product Solder paste is a suspension of alloy powder in flux, and its behaviour depends on the chemistry as much as on the metal. The flux controls the oxides, the tack and the slump, and it changes with temperature…

Thermal Imaging for Board Bring-Up Why Heat Tells the Story Every electrical fault leaves a thermal signature. A shorted device draws current and gets hot, a high resistance joint dissipates power, a component that is marginally rated runs warmer than its neighbours, and a reverse polarity part can be found…

New Product Introduction for Electronics What NPI Covers New product introduction is the process that takes a design from the engineer’s bench to a repeatable production line, and its output is a product that can be built at the target cost and quality by people who did not design it.…

What Actually Drives PCB Cost Cost Is Set in the Design Most of the cost of a board is decided before a purchase order exists, and it is decided by the design rather than by the negotiation. Area, layer count, material, tolerances, finish and the amount of testing all follow…

Quick-Turn Prototyping and Cycle Compression What Quick Turn Really Buys A quick turn service buys calendar time, and calendar time is the resource a development programme is shortest of. The value is not the board itself but the number of design iterations that fit before a deadline, because each iteration…

PCB Lead Times: What Actually Drives Them The Shape of a Lead Time A quoted lead time is a sum, not a number. It is the engineering review, the material purchase, the fabrication queue, the drilling, plating, imaging and etching steps, the solder mask, the finish, the electrical test, the…

Traceability in Electronics Manufacturing What Traceability Has to Answer Traceability is the ability to answer three questions: what went into this unit, when and where was it made, and what else was made the same way. Those questions are asked after a defect is found, a supplier issues a recall…

First Article Inspection for Assemblies What FAI Is For First article inspection is the structured check of the first unit produced by a new process, a new program or a changed design, and its purpose is to prove that the process can make the drawing before the process makes thousands…