INSPECTION APPARATUS FOR PRINTED CIRCUIT BOARDS

• US 3,787,768 A
• Filed: 12/21/1971
• Issued: 01/22/1974
• Est. Priority Date: 12/25/1970
• Status: Expired due to Term

• Current Assignee: Michio Kato, Tadashi Kubota
• Original Assignee: Michio Kato, Tadashi Kubota
• Inventors: Kubota, Tadashi, Kato, Michio
• Primary Examiner(s): Rolinec, Rudolph V.
• Assistant Examiner(s): Karlsen, Ernest F.
• Application Number:
  US05/210,457
• Time in Patent Office: 763 Days
• Field of Search: 324/158F,158P,158R,73PC,73R
• US Class Current: 324/757.02
• CPC Class Codes: G01R 1/06705 Apparatus for holding or moving single probes for moving multiple probe heads or ICs under test G01R31/2886
• CPC Class Codes: G01R 1/07328 for testing printed circuit boards
• CPC Class Codes: G01R 19/145 Indicating the presence of current or voltage
• CPC Class Codes: G01R 31/2805 Bare printed circuit boards

Abstract

A printed circuit board inspection apparatus for automatically inspecting the electrical continuity of a printed circuit printed on and through-holes formed in a substrate board according to a predetermined program prior to mounting electric parts in the through-holes to form a desired electric circuit, which is so constructed as to ensure the electrical continuity of the printed circuit printed on and through-holes formed in a substrate board.

Claims

1. A printed circuit board inspection apparatus comprising a table having a station provided with a window opening for carrying a printed circuit board with the opposite sides thereof exposed and an auxiliary station of a similar construction, inspection heads disposed above and below said table and mounted on shifting mechanisms including longitudinal and transverse shifting motors which are actuated by pulses for shifting said heads in the longitudinal and transverse directions, respectively, said inspection heads being vertically movably mounted and having a plurality of contactor needles, first air cylinder means for vertically moving at least one of said inspection heads into contact with said printed circuit board carried on said table, and second air cylin-der means for moving said one inspection head and said first air cylinder means as a unit in the vertical direction.

2. A printed circuit board inspection apparatus according to claim 1 wherein each of the inspection heads arranged above and below said table is associated with origins for longitudinal and transverse movements therefrom and means for confirming the restoration of said inspection heads to the origins upon completion of the inspection of one printed circuit board.

3. A printed circuit board inspection apparatus according to claim 1 wherein each of said inspection heads is vertically moved by an air cylinder operated by way of an air pilot type directional control valve and the pressure of said air pilot is obtained by a sensor including a baffle plate rotated by a second pulse motor and adapted to interrupt a compressed air flow.

4. A printed circuit board inspection apparatus according to claim 1 wherein each of said inspection heads comprises a block made of an electric insulating material and a plurality of contactor needles vertically movable and supported therein by springs and guided by bushes respectively, said contactor needles each having a projection so as to increase the contacting effect between the needle and the spring.

5. A printed circuit board inspection apparatus according to claim 4, wherein each of said inspection heads comprises a block made of an electric insulating material carrying a plurality of said contactor needles, springs vertically movable and supporting said contactor needles respectively, leads supporting said springs respectively, a holder, a printed circuit plate secured between said holder and said block and electrically connected with said contactor needles through said springs and said leads, and current conducting terminals provided on said printed circuit plate.

6. A printed circuit board inspection apparatus comprising a table having a station provided with a window opening for carrying a printed circuit board with the opposite sides thereof exposed and an auxiliary station of a similar construction, inspection heads disposed above and below said table and mounted on shifting mechanisms including longitudinal and transverse shifting motors which are actuated by pulses for shifting said heads in the longitudinal and transverse directions, respectivelY, said inspection heads being vertically movably mounted and having a plurality of contactor needles, first air cylinder means for vertically moving at least one of said inspection heads into contact with said printed circuit board carried on said table, and second air cylinder means for moving said one inspection head and said first air cylinder means as a unit in the vertical direction, a point of origin being provided for the longitudinal and transverse movements of the inspection heads, means for returning the inspection heads to said point of origin when the inspection of one printed circuit board is completed, said returning means comprising indicating scales which are actuated by said shifting mechanisms for indicating the exact positions of said inspection heads near the point of origin.