Epithelial cell contamination on microchip
This is a scan of a 4x5 Polaroid color photo I took at work in the summer of 1975. It shows why production workers in an area where microchip wafers are manufactured or chips used in circuit assembly are required to wear face masks. Just speaking near an exposed microchip while going without a mask can result in a nearly microscopic droplet of saliva being projected from your mouth onto the chip surface. Here a tiny droplet containing an epithelial cell has landed on the circuit side of the chip causing, after evaporation, an area of contamination. The cell nucleus is the dark spot in the center. There seems to be an area of "bleed-out" contamination surrounding the cell, outside the cell wall.
Zeiss Ultraphot IIc microscope , reflected light, Epiplan 16/0.35 objective, Optovar setting 2x, 4x5 internal camera extension set at max (approx. 480x).
Scan056K
Epithelial cell contamination on microchip
This is a scan of a 4x5 Polaroid color photo I took at work in the summer of 1975. It shows why production workers in an area where microchip wafers are manufactured or chips used in circuit assembly are required to wear face masks. Just speaking near an exposed microchip while going without a mask can result in a nearly microscopic droplet of saliva being projected from your mouth onto the chip surface. Here a tiny droplet containing an epithelial cell has landed on the circuit side of the chip causing, after evaporation, an area of contamination. The cell nucleus is the dark spot in the center. There seems to be an area of "bleed-out" contamination surrounding the cell, outside the cell wall.
Zeiss Ultraphot IIc microscope , reflected light, Epiplan 16/0.35 objective, Optovar setting 2x, 4x5 internal camera extension set at max (approx. 480x).
Scan056K