Punching and riveting assembly of a heat dissipater and heat conducting tubes

A heat dissipating device comprising:

• a plurality of heat dissipating fins arranged in parallel;
• each of the fin having a plurality of via holes;
• each via hole having a slot;
• each via hole having an annular wall protruded from the respective fin so as to increase the clamping force of the via holes to the heat dissipating tubes;
• the via holes of the fins being aligned so that the plurality of fins being formed with a plurality of through holes;
• a plurality of heat dissipating tubes located in the through holes formed by the via holes;
• each via hole only receives one heat dissipating tube;
• a size of each heat dissipating tube being smaller than that of each via hole;
• wherein the heat dissipating tubes are tightly engaged in the via holes by punching.

A method for punching heat dissipating tubes to fins comprising the steps of:

• a plurality of heat dissipating fins arranged in parallel;
• wherein each of the fin has a plurality of via holes;
• each via hole has a slot;
• each slot is extended to one edge of the respective fin;
• each via hole has an annular wall protruded from the respective fin;
• aligning the via holes of the fins aligned so that the plurality of fins are formed with a plurality of through holes;
• inserting a plurality of heat dissipating tubes into the through holes formed by the via holes;
• each via hole only receiving one heat dissipating tube;
• wherein a size of each heat dissipating tube is smaller than that of each via hole so that a gap is formed between the heat dissipating tube and the respective via hole;
• positioning the fins upon a fixture.
• using a plurality of punching plates to impact the heat dissipating tubes through the slots;
• the heat dissipating tubes will collide the walls of the via holes so as to deform and then the heat dissipating tubes are clamped tightly by the walls of the via holes;
• moreover the contact areas between the walls of the via holes and the outer walls of the heat dissipating tubes are enlarged so that the heat dissipation of the fins are increased.