Apr27
How EMS fabricate a PCB Assembly?

post on April 27, 2015

How EMS fabricate a PCB Assembly?

How EMS (Electronic Manufacturing Services) fabricate a PCB (Printed Circuit Board) Assembly?

This article is writing for the people who still not yet really under what is the PCB Assembly. Because WorkingBear found there are many people just come to this EMS area and still not yet well understand what is SMT (Surface Mount Technology) and what is Wave Soldering.

The PCB Assembly is a very popular technology in modem electronic industry.  For example, the cell phone, Tablet, Computer, Television, Remote toy car, etc. all have the PCB Assembly module  inside. The  invention of PCB Assembly technology is really help the electric products development trend to small size and multi-function.

So, how EMS fabricate a PCB Assembly? It is almost automatic production line now through SMT or wave soldering process to solder the electronic components on the board to instead of hand soldering by iron. Of course, you still can hand solder all electronic components on the board as manual by yourself but you must take high risk for the poor solderability quality and can’t do it mass production. Besides, the 0201 small chip are hard to be hand soldered on board and some of the package that design the soldering pads under the package body can’t be hand soldered. For example BGA, QFN, LGA package.

read more…》

Manufacture, SMT, Soldering     WorkingBear    Views (16,115)     comments (2)
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Apr24
How to select a good actuator design for right angle connector?

post on April 24, 2015

Right angle connector or flip lock connectorAs my personal feeling that Right-angle FPC ZIF connector is really more easily to use than Drawer type of ZIF connector. Even right-angle connector is good but do you know how to select a good design of this kind of right angle connector?

Recently my company met lots of component broken troubles for the electrical connector call “right angle connector” or “flip lock connector” in manufacturing production line. We found almost the defect connector broke at the ACTUATOR portion while operators first time tried to lift it after SMT high temperature reflow process. I’m sure the connector works fine before reflow.

I did a study on the connector and found it was caused by the connector itself while through SMT high temperature reflow process as below two reasons:

read more…》

Connector, Design, Manufacture, Quality     WorkingBear    Views (5,382)     comment (0)

Apr23
The benefit to use shielding clips to instead of shielding frame

post on April 23, 2015

SMT can clipFor most RF (Radio Frequency) devices, the PCB needs a shielding frame or shielding can to reduce the effects of EMI (Electromagnetic Interference). A common design uses a shielding frame that is soldered to the PCB, along with a separate shielding can that fits over the frame to enclose and isolate the RF circuitry.

This means that two sets of stamping tools are typically required before implementing this solution, which adds to the initial tooling cost. In addition, the shielding frame must be mounted to the PCB using the SMT machines and process. This requires tight flatness control to ensure reliable solder joints. Most shielding frame designs require a maximum flatness of around 0.12 mm, while some even require flatness below 0.10 mm.

This can be challenging because typical stencil thicknesses are only around 0.10–0.127 mm or thinner. Maintaining such tight flatness requirements makes the shielding frame more difficult and expensive to manufacture.

read more…》

Design, SMT, Soldering     WorkingBear    Views (8,309)     comment (0)

Apr23
How We Solved the Keypad Sensitivity Issue by Switching to a 3-Dimple Metal Dome Design

post on April 23, 2015

metal_dome_5_dimples

In my previous post, I mentioned that our company once used metal domes without dimples as the keypad contact solution—similar to what’s used in some cell phones. However, we soon ran into a problem: the keypads were not sensitive enough when pressed.

We eventually solved this issue by switching back to metal domes with dimples, and still achieved a 1,000,000-cycle finger press lifetime.

read more…》

Design, Keypad, Quality     WorkingBear    Views (7,940)     comments (2)
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Apr22
The Importance of Dimples in Metal Dome Keypads

post on April 22, 2015

Keypad contact pad with fiber contaminationforeign dust contaminate inside metal dome and make contact fail.

Recently, our company introduced metal dome technology as a contact solution for rubber keypads, a trend also seen in many cell phone keypad designs. The advantages of using metal domes include a better key press experience, extended lifespan, and improved reliability. According to data, metal dome keypads can endure 2,000,000 finger presses compared to the 300,000 presses of poly-dome keypads. read more…》

Design, Keypad, Quality     WorkingBear    Views (7,902)     comment (0)