Micro Switch locations

According to Larry Bishop, when he started with Micro Switch in 1972, SW Series keyboards were produced in-house at Honeywell’s facilities. Hall sensor manufacturing was provided by the Plymouth, Minnesota works; all other assembly took place at Honeywell’s Freeport, Illinois plants. The Hall sensors aside, all other semiconductor parts were sourced from third parties such as Motorola (for DTL) and American Microsystems and Texas Instruments (for single-chip encoders). The mounting rails for SW Series keyboards, and later the mounting plates for SD Series keyboards, were produced by a stamping house within the US.

With SD Series, PCB production was outsourced due to new Environmental Protection Agency regulation on harmful chemicals and production growth exceeding the plant capacity. Keycap production remained with Honeywell.

Larry provided the following details of Micro Switch locations and their relationship to keyboard production:

SSEC

Honeywell’s Solid State Electronic Center is located in Plymouth, Minnesota, and is where the Hall sensor dies were produced.

Freeport Plant 1

Plant 1 was an old cheese factory east of the Pecatonica River. SW Series switch housings were manufactured here. The plant was later mothballed due to excessive asbestos in the ceilings and ageing of the structure.

Freeport Plant 2

Plant 2 was built for a buggy company, and was owned by a Hurst car company before ownership transferred to Micro Switch. Double-shot keycap moulding took place here. PCB manufacturing also took place here, two floors up. The Hall sensors were placed into their packaging and protective gel was applied over the the die.

Freeport Plant 4

Plant 4 was on the south side of Freeport, and it grew to a massive ultra-modern facility. This is where keyboards were packaged up and shipped out.