Method and apparatus for designing printed-circuit board
AssigneeFujitsu Limited
InventorsHiroki Uchida, Yasuo Yamagishi
Life of this patent
Estimating the term…
Abstract
A thermal analysis in heating a print-circuit board in a reflowing furnace is simulated by a processor using data required for the design and thermal analysis of the printed-circuit board that carries solder-bonded components. The result of simulation indicates the possibility of existence of unmelted solder bonds heated at peak temperature below a predetermined lower limit and solder bonds heated at temperature above a predetermined upper limit. On the basis of the result, the components that are likely to be heated at inapplicable temperature are redesigned so that they can actually be heated at temperature in the predetermined range. The modification of design is displayed.
Claims8
A method for designing a printed-circuit board comprising the steps of:
- a. inputting beforehand data necessary for designing and thermally analyzing a printed-circuit board on which a component having a solder joint is mounted;
- b. thermally analyzing the printed-circuit board by simulating the heating of the printed-circuit board in a reflow furnace with use of the input data necessary for the thermal analysis;
- c. evaluating from a result of the thermal analysis whether or not there exists at least either one of an unmelted solder joint whose peak temperature does not reach a predetermined lower limit temperature at heating and an over-heated component whose temperature exceeds a predetermined upper limit temperature at heating;
- d. according to a result of the above evaluation, changing a design of a component having the unmelted solder joint and/or the over-heated component so that the temperature of the unmelted solder joint and/or the over-heated component is within a range from the lower limit temperature to the upper limit temperature;
- and
- e. outputting the result of change of the design.
An apparatus for designing a printed-circuit board comprising:
- a. an input section for inputting beforehand data necessary for designing and thermally analyzing a printed-circuit board on which a component having a solder joint is mounted;
- b. a reflow thermal analyzing section for thermally analyzing the printed-circuit board by simulating the heating of the printed-circuit board in a reflow furnace with use of the input data necessary for the thermal analysis;
- c. a design section for evaluating from a result of the thermal analysis whether or not there exists at least either one of an unmelted solder joint whose peak temperature does not reach a predetermined lower limit temperature at heating and an over-heated component whose temperature exceeds a predetermined upper limit temperature at heating, and, according to a result of the above evaluation, changing a design of a component having the unmelted solder joint and/or the over-heated component so that the temperature of the unmelted solder joint and/or the over-heated component is within a range from the lower limit temperature to the upper limit temperature;
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- d. an output section for outputting the result of change of the design.
A computer-readable recording medium containing thereon a program for designing a printed-circuit board, the program having the functions of:
- a. causing a computer operation to input beforehand data necessary for designing and thermally analyzing a printed-circuit board on which a component having a solder joint is mounted;
- b. causing a computer operation to thermally analyze the printed-circuit board by simulating the heating of the printed-circuit board in a reflow furnace with use of the input data necessary for the thermal analysis;
- c. causing a computer operation to evaluate from a result of the thermal analysis whether or not there exists at least either one of an unmelted solder joint whose peak temperature does not reach a predetermined lower limit temperature at heating and an over-heated component whose temperature exceeds a predetermined upper limit temperature at heating;
- d. causing a computer operation to change a design of a component having the unmelted solder joint and/or the over-heated component so that the temperature of the unmelted solder joint and/or the over-heated component is within a range from the lower limit temperature to the upper limit temperature according to a result of the above evaluation;
- and
- e. causing a computer operation to output the result of change of the design.
Dependencies are inferred from the claim text.