The diagnosis and modification of mistakes in cad data is studied , the method is presented and a real example is given . development environments of vm systems are compared and some suggestions are given . in the end of the paper , a vm software for smt is developed which shows that all the techniques mentioned above can work correctly , so they can be used as reference on the research of vm technology for other industries 本文深入地研究了vm中存在的問題,對(duì)vm系統(tǒng)中必須解決的八個(gè)關(guān)鍵技術(shù)進(jìn)行了研究,并給出了相應(yīng)的解決方案:對(duì)于無縫連接提出了新的定義,并制訂了vm表貼子系統(tǒng)的格式;研究了pcb版圖的恢復(fù)問題;完成了器件庫的建立工作;探討了vm對(duì)cad數(shù)據(jù)進(jìn)行差錯(cuò)、驗(yàn)證和修改,并針對(duì)實(shí)例給出了一個(gè)對(duì)應(yīng)的解決方法;對(duì)開發(fā)環(huán)境作了比較研究,提出了一種vm系統(tǒng)開發(fā)環(huán)境,即以vc + +和opengl為核心的建立方法;開發(fā)了vm表貼子系統(tǒng),驗(yàn)證了幾個(gè)關(guān)鍵技術(shù)。