Automatic assembly method for making photovoltaic panels with cells of crystalline silicon of the traditional type with top-bottom contacting, that is to say, with the positive and negative electrical contacts placed on opposite faces of the same cell, interconnected with a partial superimposition, that is to say, shingled, being entire or subdivided into portions identical to each other called equivalent cell portions (403a, 403b, 403c, 403d), said assembly method including a first phase of positioning (101, S1) of a backsheet with an encapsulating layer on a panel-holding tray that horizontally crosses the workstations (S1 - S6) of an automatic plant (30, 400), and including a following macro-phase of printing of ECA conductive adhesive on the electrical contacts of said cells or portions also comprising the loading and pre-fixing on the encapsulating layer of the backsheet, then including a phase of superimposition (104, S4) of an upper encapsulating layer, then a phase of laying (105, S5) of the front glass, and finally a phase of overturning (106, S6) of the panel for sending it to the rolling furnace; said assembly method being characterised in that in the macro-phase said portions are pre-arranged in shingled strings according to a macro-phase of lay-up in which ECA is printed on the upward-facing contacts (205, 207) of said portions after picking them from a box (203, R1a - R1b), spacing them apart (217, 403a - 403d) and laying them on a pneumatic belt, and wherein then in said macro-phase a printed portion is individually laid (403a, 403b, 403c, 403d) onto another in a superimposition on said contacts (207, 404) in such a way as to progressively pre-arrange in a continuous cycle (20, 210, R2) shingled strings, which are complete and ready to be loaded and pre-fixed on said backsheet; said printing of ECA on said portions (403a - 403d), said pre-arrangement of said shingled strings (402, 404) and said loading with pre-fixing on said backsheet being simultaneously carried out by means of said macro-phase in one single automatic and multi-function workstation called combined station of lay-up; said pre-arrangement of shingled strings being performed with an integrated system of means (20, 210, R2) comprising at least one mobile support of the shuttle-tray type with a bidirectional back-forth translation with vacuum for holding, and a robotic handler coordinated with it (210, 211) in the movements being provided with a pneumatic gripping hand (212, 214) with independent sections, with chocked vacuum channels (215a, 215b, 215c, 215d) for picking said just printed equivalent cell portions by groups and releasing them one at a time (403a, 403b, 403c, 403d) by laying them in a partial superimposition (207, 404) on said shuttle-tray (210, 211) that moves in a synchronized way like a plotter, in such a way as to progressively form in both directions of translation (211a, 211b) said shingled string ready to be picked as an entire, transported, oriented, laid and pre-fixed on said encapsulating layer of the backsheet with a handler of the Cartesian bridge type intended to apply pneumatic vacuum and localised heating on each equivalent cell portion (403a - 403d).