| 摘要 |
PURPOSE:To obtain a ceramic substrate reduced in warp by introducing high- temperature retaining time in cooling process after burning a green sheet for ceramic substrate. CONSTITUTION:In a method for burning and then cooling a green sheet for ceramic substrate to produce the objective ceramic substrate, a process for keeping the sheet at a temperature higher than 1100 deg.C once during cooling is provided. The temperature in high-temperature retention requires a temperature higher than 1100 deg.C and is preferably lower than the burning temperature and temperature higher than the burning temperature is undesirable. When the sheet is retained in a temperature lower than 1100 deg.C, reduction of warp is not practiced. The warp in the resultant ceramic substrate is reduced and e.g. can be suppressed to a warp value no higher than 0.15 in 100mmX100mm dimension which is the standarized limit value of ceramic substrate. Consequently, any correction of warp becomes unnecessary. |
