1. 数量与位置：设在转角处的扣位应尽量靠近转角；

1. The quantity and location: located in the corner of the button should be near the corner as far as possible;

2. 结构形式与正反扣：要考虑组装、拆卸的方便，考虑模具的制作；

2. The structure and the positive and negative buckle, want to consider the convenience of assembly, disassembly, considering the mould production;

3. 卡扣处应注意防止缩水与熔接痕；

3. Card buckle should pay attention to prevent shrinkage and weld mark;

4. 朝壳体内部方向的卡扣，斜销运动空间不小于5mm；

4. In the direction of the shell inside card buckle, pin movement space is not less than 5 mm;