Method for forming switching circuit of keyboard without generating phantom phenomenon

A method for forming a switching circuit of a keyboard comprising the following steps:

• (1) forming a matrix of intersection nodes of input/output terminals, the matrix having a diagonal direction;
• (2) selecting nodes of the matrix to define a first, reference diagonal line extending in the diagonal direction, the reference line dividing the matrix into first and second portions;
• (3) selecting nodes of the matrix in the first portion to define a first portion diagonal line, the first portion diagonal line being parallel to the reference line, the nodes of the first portion diagonal line being located at a first distance from the reference line and forming no rectangle with the nodes of the reference line;
• (4) selecting nodes of the matrix in the second portion to define a second portion diagonal line;
• the second portion diagonal line being parallel to the reference line, the nodes of the second portion diagonal line being located at a second distance different from the first distance and forming no rectangle with the nodes of the reference line and the first portion diagonal line;
• and
• (5) setting switches in the nodes of the diagonal lines.