An electronic assembly, comprising: a carrier having at least one mounting hole there through; a daughter board having a mounting recess along a side thereof; a spacer for installation on the carrier to provide mounting and fixation for the daughter board, the spacer extending through one of the at least one mounting holes, the spacer comprising: an outer body; a cylindrical cap on the outer body, the cylindrical cap sized to align with the mounting recess of the daughter board and having a diameter less than a width of the outer body; a cylindrical stage extending from the outer body in a direction opposite the cylindrical cap and having a diameter less than a width of the outer body, the cylindrical stage sized in relation to a diameter of the at least one mounting hole on the carrier; a threaded bore extending through the cylindrical cap and outer body and into the cylindrical stage; an outer thread extending on an external surface of the cylindrical stage, the outer thread having a distal outer thread and a proximal outer thread for self-threading such that insertion of the spacer into the at least one mounting hole in the carrier causes an interior of the at least one mounting hole to become threaded; and a screw extending through the threaded bore, wherein the electronic assembly is configured to removably clamp the daughter board at the mounting recess to the spacer, once the mounting recess of the daughter board is aligned with the cylindrical cap on the outer body of the spacer, by applying a screw in the threaded bore. a carrier having at least one mounting hole there through; a daughter board having a mounting recess along a side thereof; a spacer for installation on the carrier to provide mounting and fixation for the daughter board, the spacer extending through one of the at least one mounting holes, the spacer comprising: an outer body; a cylindrical cap on the outer body, the cylindrical cap sized to align with the mounting recess of the daughter board and having a diameter less than a width of the outer body; a cylindrical stage extending from the outer body in a direction opposite the cylindrical cap and having a diameter less than a width of the outer body, the cylindrical stage sized in relation to a diameter of the at least one mounting hole on the carrier; a threaded bore extending through the cylindrical cap and outer body and into the cylindrical stage; an outer thread extending on an external surface of the cylindrical stage, the outer thread having a distal outer thread and a proximal outer thread for self-threading such that insertion of the spacer into the at least one mounting hole in the carrier causes an interior of the at least one mounting hole to become threaded; and a screw extending through the threaded bore, wherein the electronic assembly is configured to removably clamp the daughter board at the mounting recess to the spacer, once the mounting recess of the daughter board is aligned with the cylindrical cap on the outer body of the spacer, by applying a screw in the threaded bore. an outer body; a cylindrical cap on the outer body, the cylindrical cap sized to align with the mounting recess of the daughter board and having a diameter less than a width of the outer body; a cylindrical stage extending from the outer body in a direction opposite the cylindrical cap and having a diameter less than a width of the outer body, the cylindrical stage sized in relation to a diameter of the at least one mounting hole on the carrier; a threaded bore extending through the cylindrical cap and outer body and into the cylindrical stage; an outer thread extending on an external surface of the cylindrical stage, the outer thread having a distal outer thread and a proximal outer thread for self-threading such that insertion of the spacer into the at least one mounting hole in the carrier causes an interior of the at least one mounting hole to become threaded; and a screw extending through the threaded bore, wherein the electronic assembly is configured to removably clamp the daughter board at the mounting recess to the spacer, once the mounting recess of the daughter board is aligned with the cylindrical cap on the outer body of the spacer, by applying a screw in the threaded bore.