Multilevel semiconductor module and method for fabricating the same

A method for fabricating a multilevel semiconductor module, the method comprising the steps of:

• (a) preparing one or more first resin boards, a second resin board and one or more sheet members, each of the first resin boards having an upper face on which a semiconductor chip is mounted and including one or more first buried conductors, the second resin board having an upper face on which a semiconductor chip is mounted, including one or more first buried conductors and having a thickness larger than that of each of the first resin boards, each of the sheet members including a resin base having an opening larger than the semiconductor chip when viewed from above, an adhesive member placed on at least one of upper and lower faces of the resin base and one or more second buried conductors penetrating the resin base;
• (b) placing the second resin board at the bottom and alternately stacking the sheet members and the first resin boards over the second resin board so that the semiconductor chip is housed in the opening;
• and
• (c) applying heat and pressure to the first and second resin boards and the sheet members stacked at the step (b) from the bottom and the top of the stacked structure so as to bond the first and second resin boards and the sheet members together, connect the first buried conductors and the second buried conductors to each other, and cause the adhesive member to flow so that the semiconductor chip is covered with the adhesive member.

A method for fabricating a multilevel semiconductor module, the method comprising the steps of:

• (a) preparing one or more first resin boards, a second resin board, one or more sheet members and one or more low-stress members, each of the first resin boards having an upper face on which a semiconductor chip is mounted and including one or more first buried conductors, the second resin board having an upper face on which a semiconductor chip is mounted, including one or more first buried conductors and having a thickness larger than that of each of the first resin boards, each of the sheet members including a resin base having an opening larger than the semiconductor chip when viewed from above, adhesive layers placed on upper and lower faces of the resin base in respective regions surrounding the opening when viewed from above and one or more second buried conductors penetrating the resin base, each of the low-stress members being made of a resin having a softening point lower than that of each of the adhesive layers and a stiffness lower than that of each of the adhesive layers, each of the low-stress members being smaller than the opening when viewed from above;
• (b) placing the second resin board at the bottom, alternately stacking the sheet members and the first resin boards over the second resin board so that the semiconductor chip is housed in the opening, and placing the low-stress members on associated ones of the semiconductor chips;
• and
• (c) applying heat and pressure to the first and second resin boards and the sheet members stacked at the step (b) from the bottom and the top to cause the low-stress members to flow so that the semiconductor chips are covered with the respective low-stress members, and
• (d) heating the first and second resin boards and the sheet members stacked at the step (b) from the bottom and the top to a temperature higher than a temperature at the step (c) with application of pressure, thereby bonding the first and second resin boards and the sheet members together and connecting the first buried conductors and the second buried conductors to each other.