JP2008091692A - Manufacturing method for semiconductor circuit module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a semiconductor circuit module which reduces the possibility of faulty conduction of semiconductor chips by enhancing the junction strength between a connection pad and a stud bump. <P>SOLUTION: The manufacturing method for a semiconductor circuit module 1 comprises steps A to E. A step A forms a stud bump 4 on the smooth top surface of a semiconductor chip 2. Steps B and C form a connection pad 5A having a both-side wall 6A with inner width W2 almost equivalent to outer width W1 of a stud 4a on the smooth top surface of a mounting circuit 3A, then form a metal junction film 8 on the top surface of the both-side wall 6A. Subsequently, steps D and E pressurize and insert the stud 4a into the both-side wall 6A, and closely attach a side face 4b of the stud 4a onto an inner face 6Aa of the both-side wall 6A, then joint the stud bump 4 to the both-side wall 6A by heating the metal junction film 8. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a method for manufacturing a semiconductor circuit module, and in particular, a semiconductor circuit module that can be suitably used for manufacturing a semiconductor circuit module obtained by flip-chip mounting a semiconductor chip having stud bumps on a mounting circuit. It relates to the manufacturing method.

  In recent years, many semiconductor circuit modules obtained by mounting a semiconductor chip on a mounting circuit such as a flexible printed wiring board are mounted on small mobile devices such as mobile phones and laptop computers. There are several mounting methods used for this semiconductor circuit module. Recently, flip-chip mounting has attracted particular attention. One of the merits of using flip chip mounting is that the semiconductor chip and the mounting circuit can be bonded together. A conventional method of manufacturing a semiconductor circuit module will be described below from the viewpoint of joining.

  A conventional semiconductor circuit module is manufactured through a bump forming process, a connection pad forming process, a metal bonding film forming process, and a bonding process. In the bump forming step, a plurality of stud bumps are formed on the surface of the semiconductor bare chip using a wire bonder. Generally, this stud bump is formed using Au wire. In the connection pad forming step, a plurality of connection pads are formed in a flat plate shape on the surface of the mounting circuit. As a material used for this connection pad, a highly conductive metal such as Au, Cu, Al, or Ag is used.

  In the metal bonding film forming step, a metal bonding film is formed on the surface of the connection pad by solder paste, solder plating, or Sn plating. Here, as shown in FIG. 17, when the metal bonding film 108 is formed thick, the metal bonding film 108 is melted in a subsequent bonding step to cover the side surface 104 b of the stud bump 104, and the metal bonding film 108. Since the contact area between the stud bump 104 and the stud bump 104 is increased, it is easy to increase the bonding strength. Therefore, it is preferable to form the metal bonding film 108 as thick as possible.

  In the bonding process, the stud bump 104 and the connection pad 105 are heated by bringing the tip 104c of the stud bump 104 into pressure contact with the surface 105a of the connection pad 105 through the metal bonding film 108 and then heating the metal bonding film 108. Join. Since the stud bumps 104 are formed on the same surface, the stud bumps 104 and the connection pads 105 can be joined together by adjusting the height of the stud bumps 104 (see Patent Document 1).

JP 2005-158814 A

  However, as shown in FIG. 18, when the metal bonding film 108 cannot be formed thick, such as when the metal bonding film 108 is formed by electroless plating, the contact area between the metal bonding film 108 and the stud bump 104 is small. Therefore, there is a problem that the bonding strength between the stud bump 104 and the connection pad 105 is insufficient. If the bonding strength is insufficient, peeling occurs between the stud bump 104 and the connection pad 105, which causes a conduction failure of the semiconductor circuit module 101.

  Further, since the tip 104c of the stud bump 104 protrudes in a stud shape, it is difficult to increase the contact area of the stud bump 104 with respect to the planar connection pad 105.

  Therefore, the present invention has been made in view of these points, and by increasing the bonding strength between the connection pad and the stud bump, a semiconductor circuit module capable of manufacturing a semiconductor circuit module that is less likely to cause poor conduction of a semiconductor chip. The object is to provide a method of manufacturing a circuit module.

  In order to achieve the above-described object, a method for manufacturing a semiconductor circuit module according to the present invention includes, as a first aspect, a step A of forming a plurality of stud bumps having the same height on a smooth surface of a semiconductor chip, and a step Either before or after A, a connection pad having both side walls having an inner width approximately equal to the outer width of the stud formed on the stud bump or an inner width smaller or larger than the outer width of the stud by a predetermined length is mounted. Step B for forming on the smooth surface of the circuit, Step C for forming a metal bonding film on the surface of the connection pad as the surface layer of the connection pad, and after step C, studs are pressed and inserted inside the side walls. If the inner width of both side walls differs from the outer width of the stud by pressing the side or tip of the stud against the inner surface of both side walls or the smooth bottom surface surrounded by both side walls, When the inner width of both side walls is approximately the same as the outer width of the stud, the step D in which the side surfaces of the studs are in close contact with the inner side surfaces of the both side walls and the metal after the step D are deformed. And a step E of bonding the stud bump to the connection pad by heating the bonding film.

  According to the manufacturing method of the semiconductor circuit module of the first aspect of the present invention, the contact area between the stud bump and the contact pad can be made larger than before, so the bonding strength between the stud bump and the contact pad is increased. be able to. In addition, since the side surfaces of the studs are in close contact with the inner side surfaces of both side walls, the bonding strength between the stud bumps and the contact pads can be increased even when the metal bonding film cannot be formed thick. it can.

  The method for manufacturing a semiconductor circuit module according to the second aspect of the present invention is the method for manufacturing a semiconductor circuit module according to the first aspect, wherein the stud bump has Au or an Au alloy containing Au as a main component or a surface film thereof. It is characterized by being formed using a metal (including an alloy).

  According to the method for manufacturing a semiconductor circuit module of the second aspect of the present invention, the stud can be easily deformed in the width direction when the stud is pressure-inserted inside the both side walls in the step D. In addition, since Au is excellent in conductivity, the conductivity efficiency between the semiconductor chip and the mounting circuit can be improved.

  The method for manufacturing a semiconductor circuit module according to the third aspect of the present invention is the method for manufacturing a semiconductor circuit module according to the second aspect, wherein the metal bonding film is either lead-free solder or Sn or Sn alloy containing Sn as a main component. It is characterized in that it is formed by plating using the material No. 1.

  According to the manufacturing method of the semiconductor circuit module of the third aspect of the present invention, Au-Sn eutectic bonding can be performed between the stud bump and the connection pad using the Au stud bump. Moreover, since the side surface of the stud can be brought into close contact with the inner side surfaces of both side walls, the bonding strength between the stud bump and the contact pad can be increased even when the lead-free solder cannot be plated thick.

  The method for manufacturing a semiconductor circuit module according to the fourth aspect of the present invention is the method for manufacturing a semiconductor circuit module according to any one of the first to third aspects, wherein the stud has a smooth tip surface. In the step D, the stud is press-inserted inside the both side walls until the smooth front end surface of the stud comes into contact with the smooth bottom surface surrounded by the both side walls.

  According to the manufacturing method of the semiconductor circuit module of the fourth aspect of the present invention, the stud is brought into close contact with the both side walls from the boundary portion between the both side walls and the bottom surface by bringing the tip end surface of the stud into contact with the bottom surface. The contact area between the bump and the contact pad can be easily increased.

  The method for manufacturing a semiconductor circuit module according to the fifth aspect of the present invention is the method for manufacturing a semiconductor circuit module according to any one of the first to fourth aspects, wherein the step B includes a seed film on a smooth surface of the mounting circuit. Forming a resist film on the surface of the seed film, forming a resist film on the surface of the seed film, patterning two linear grooves at positions where both side walls are formed, and a seed film exposed from the two linear grooves A step B3 of forming both side walls by plating, a step B4 of removing the resist film after the formation of both side walls, and a step B5 of removing the seed film exposed after the removal of the resist film. It is said.

  According to the semiconductor circuit module manufacturing method of the fifth aspect of the present invention, both side walls having various shapes can be formed by appropriately changing resist patterning and plating conditions on both side walls.

  The method for manufacturing a semiconductor circuit module according to the sixth aspect of the present invention is the method for manufacturing a semiconductor circuit module according to any one of the first to fourth aspects, wherein the step B includes forming a seed film on the smooth surface of the mounting circuit. Forming a resist film on the surface of the seed film, and then patterning one linear groove having a size equivalent to the enclosed area at a position surrounded by both side walls; Step B7 for forming a metal bottom film by plating the seed film exposed from the straight groove, Step B8 for forming one resist strip parallel to one straight groove at the center of the surface of the metal bottom film, and resist Step B9 of forming both side walls on the surface of the metal bottom film by plating the metal bottom film exposed from the straight groove after the formation of the stripe, and removing the resist film and the resist stripe after the formation of the both side walls. A step B10, is characterized by comprising a step B11 of removing the resist film and a resist strip seed film exposed after removal of.

  According to the manufacturing method of the semiconductor circuit module of the sixth aspect of the present invention, since the side walls and the metal bottom film are continuously formed, a concave contact pad can be formed. As a result, since the tip and side surfaces of the stud can be brought into contact with the contact pad, the contact area between the stud bump and the contact pad can be increased. In addition, by appropriately changing the resist patterning, the shape of the resist strip, and the plating conditions on both side walls, both side walls having various shapes can be formed.

  A method for manufacturing a semiconductor circuit module according to a seventh aspect of the present invention is the method for manufacturing a semiconductor circuit module according to the fifth or sixth aspect, after step B2 and before step B3, or after step B8. Then, before the process B9, the resist film and the resist strip are heated to shrink the upper part of the resist film and the resist strip in the width direction, whereby the vertical cross section or the process of the two linear grooves formed in the process B2 Forming a vertical cross section of two straight grooves between one straight groove formed in B8 and the resist strip into a trapezoid in which the length of the upper base is longer than the length of the lower base; It is characterized by.

  According to the method of manufacturing the semiconductor circuit module of the seventh aspect of the present invention, the vertical cross section of both side walls is formed in the above-mentioned trapezoidal shape, and the inner width of both side walls decreases from the bottom to the top. The stud can be sandwiched above the both side walls to increase the bonding strength between the stud bump and the contact pad.

  The method for manufacturing a semiconductor circuit module according to the eighth aspect of the present invention is the method for manufacturing a semiconductor circuit module according to any one of the fifth to seventh aspects, wherein the top surface of the resist film in step B2 is either step B3 or step B9. Alternatively, the both side walls are plated and grown until the upper surface of the resist strip in step B8 is partially covered, thereby forming a bulging portion extending inside the both side walls above the both side walls.

  According to the method of manufacturing the semiconductor circuit module of the eighth aspect of the present invention, the bulging portions of the side walls sandwich the stud, so that the bonding strength between the stud bump and the contact pad can be increased.

  According to the method for manufacturing a semiconductor circuit module of the present invention, the contact surface between the stud bump and the contact pad can be made larger by making the side surfaces of the stud bump studs closely contact both side walls of the connection pad. The bonding strength between the pad and the stud bump is increased, and an effect is obtained that a semiconductor circuit module in which poor conduction of the semiconductor chip hardly occurs can be manufactured.

  A method for manufacturing a semiconductor circuit module according to the present invention will be described below with reference to FIGS. 1 to 16 according to first to fourth embodiments. In addition, the process and part number which are common in each embodiment are shown using the same symbol.

  First, the manufacturing method of the semiconductor circuit module 1 according to the first embodiment will be described with reference to FIGS. Here, FIG. 1 is a transparent plan view showing a connection state of the semiconductor circuit module 1, and FIG. 2 is a cross-sectional view taken along arrow 2-2 of FIG. 3 to 8 show each step in the method for manufacturing the semiconductor circuit module 1 of the first embodiment.

  As shown in FIGS. 1 and 2, the semiconductor circuit module 1 of the first embodiment includes a semiconductor chip 2 such as an IC bare chip or an LSI bare chip and a mounting circuit 3A such as a flexible printed wiring board. A plurality of stud bumps 4 having the same height are formed on the opposing surface 2a of the mounting circuit 3A on the semiconductor chip 2, and a plurality of connection pads 5A having both side walls 6A are formed on the mounting circuit 3A. Are formed at opposite positions. The studs 4a of the stud bumps 4 are press-fitted inside the both side walls 6A of the connection pads 5A and joined to each other, whereby the semiconductor chip 2 is flip-chip mounted on the mounting circuit 3A.

  The semiconductor circuit module 1 according to the first embodiment is manufactured through steps A to E as shown in FIGS.

  FIG. 3 shows step A divided into four steps. In step A, as shown in FIGS. 3A to 3D, a plurality of stud bumps 4 having the same height are formed on the smooth surface of the semiconductor chip 2 using a wire bonder. First, a linear Au wire 20 as shown in FIG. 3A is prepared, and its tip is discharged and melted to form a ball 20a as shown in FIG. 3B. As for the Au wire 20, an Au alloy wire mainly composed of Au may be used instead. Then, as shown in FIG. 3C, the ball 20a is bonded onto the smooth surface 2a of the semiconductor chip 2, and then the Au wire 20 is cut as shown in FIG. 3D to form the stud bump 4.

  Further, in this step A, by adjusting the conditions such as the Au wire diameter, the discharge condition, and the Au wire cutting position, the formation conditions such as the stud outer width W1, the ball diameter, and the stud height can be freely changed. be able to. Therefore, the stud bump 4 is formed to have a size and height adapted to the shape of the both side walls 6A of the connection pad 5A.

  Further, an Al flat plate electrode (not shown) is formed on the surface 2 a of the semiconductor chip 2 to which the stud bump 4 is bonded, so that a smooth flat surface having conductivity is formed in advance on the surface of the semiconductor chip 2. ing. In the first embodiment, the tip surface 4c of the stud 4a is formed in a smooth flat shape by cutting the wire in parallel with the surface of the semiconductor chip 2.

  In step B, as shown in FIG. 4, a plurality of connection pads 5A are formed on the smooth surface of the mounting circuit 3A. The process B of the first embodiment is performed after the process A, but even if performed before the process A, other processes are not affected. And this process B is provided with five processes from process B1 to process B5, as shown to FIG.

  In step B1, as shown in FIG. 4A, a seed film 10A is formed on the smooth surface of the mounting circuit 3A by sputtering. As the seed film 10A, when the circuit board of the mounting circuit 3A is Si, a laminated film in which a Ti layer or a Cr layer is used as a first layer and a Cu layer serving as a second layer is laminated on the surface of the first layer. Used.

  In step B2, as shown in FIG. 4B, two linear grooves 12 are formed at positions where both side walls 6A are formed on the resist film 11A formed using a novolac resist material on the surface of the seed film 10A. Pattern it. The width of each straight groove 12 is the width of each side wall on both side walls 6A, and the distance between these two straight grooves 12 is the inner width W2 of both side walls 6A. Patterned to fit the dimensions of

  In the process B3, as shown in FIG. 4C, the seed film 10A exposed from the two linear grooves 12 is plated with a metal having excellent conductivity such as Cu, Ag, Al, Au, etc. Both side walls 6 </ b> A are formed inside the straight groove 12. Since the height of both side walls 6A is lower than the thickness of the resist film 11A, the vertical cross section of each side wall of the both side walls 6A is rectangular. Further, the inner width W2 of both side walls 6A is formed to be approximately the same as the outer width W1 of the stud 4a formed on the stud bump 4. However, in the first embodiment, the stud bump 4 is formed using Au, and the stud 4a is easily deformed. Therefore, the inner width W2 of the side walls 6A is larger than the outer width W1 of the stud 4a. The predetermined length (the length by which the stud 4a is deformed at the time of pressure insertion in the step D) may be formed small (see FIG. 7) or large (see FIG. 8).

In step B4, as shown in FIG. 4D, the resist film 11A is removed after the both side walls 6A are formed. As the resist remover, N-methyl-2-pyrrolidone (molecular formula: C ₅ H ₉ NO, trade name: NMP) is used.

  In step B5, as shown in FIG. 4E, the seed film 10A exposed after the removal of the resist film 11A is removed. The removal of the seed film 10A is performed by ion milling. The process B is completed through these processes B1 to B5.

  In step C, as shown in FIG. 5, a metal bonding film 8 is formed on the surface of the connection pad 5A (including both side walls 6A as a matter of course). The metal bonding film 8 may be formed by plating using lead-free solder such as Sn—Ag—Cu solder, Sn—Ag solder, Sn—Cu solder, or Sn or Sn as a main component. Plating may be formed using an Sn alloy. This plating method may be either electroplating or electroless plating. Since the metal bonding film 8 is a surface layer of the connection pad 5A and both side walls 6A, the metal bonding film 8 is the surface of the connection pad 5A or both side walls 6A unless otherwise specified in the process D and the process E. It also means the surface of

  In the process D, as shown in the order of FIGS. 6A and 6B, the stud bump 4 is formed in the process A, and after forming the metal bonding film 8 on the surface of the connection pad 5A in the process C, the semiconductor chip 2 is formed. The mounting position of the mounting circuit 3A is aligned, and the stud 4a of the stud bump 4 is press-inserted inside the side walls 6A of the connection pad 5A using a flip chip bonder. Since the inner width W2 of both side walls 6A is formed to be approximately the same as the outer width W1 of the stud 4a in the process B, when the stud 4a of the stud bump 4 is pressure-inserted inside the both side walls 6A, the side surface 4b of the stud 4a. Contacts the inner side surface 6Aa of the side walls 6A, and the tip 4c of the stud 4a contacts the smooth bottom surface 3Aa surrounded by the side walls 6A. As a result, the side surface 4b of the stud 4a is in close contact with the inner side surface 6Aa of the both side walls 6A.

  In the first embodiment, the stud bump 4 is formed using Au, and the stud 4a is easily deformed. Therefore, the inner width W2 of the side walls 6A is different from the outer width W1 of the stud 4a. Even in this case, the side surface 4b of the stud 4a is in close contact with the inner side surface 6Aa of the both side walls 6A.

  For example, when the inner width W2 of both side walls 6A is formed to be smaller than the outer width W1 of the stud 4a by a predetermined length as shown in FIG. 7A, the stud 4a of the stud bump 4 is formed as shown in FIG. 7B. When pressure is inserted inside the side walls 6A, the front end 4c and the side surface 4b of the stud 4a receive drag from the side walls 6A, and the stud 4a shrinks and deforms inward in the width direction. It becomes approximately the same as the inner width W2 of the wall 6A. Accordingly, the side surface 4b of the stud 4a abuts on the inner side surface 6Aa of the side walls 6A, and the tip 4c of the stud 4a abuts on the smooth bottom surface 3Aa surrounded by the side walls 6A. 4b adheres to inner side surface 6Aa of both side walls 6A.

  8A, when the inner width W2 of both side walls 6A is formed to be larger than the outer width W1 of the stud 4a by a predetermined length, the stud 4a of the stud bump 4 is formed as shown in FIG. 8B. When pressure is inserted inside the side walls 6A, the front end 4c of the stud 4a contacting the bottom surface 3Aa receives a drag from the bottom surface 3Aa, and the stud 4a expands and deforms outward in the width direction, so the outer width W1 of the stud 4a. Becomes approximately the same as the inner width W2 of the side walls 6A. Accordingly, the tip 4c of the stud 4a contacts the smooth bottom surface 3Aa surrounded by the side walls 6A, and the side surface 4b of the stud 4a contacts the inner side surface 6Aa of the side walls 6A. 4b adheres to inner side surface 6Aa of both side walls 6A.

  In step E, after the side surface 4b of the stud 4a is brought into close contact with the inner side surface 6Aa of both side walls 6A (after step D), the metal bonding film 8 is heated and cooled using a flip chip bonder to thereby perform metal bonding. The film 8 is melted and solidified, and the stud bump 4 is bonded to the connection pad 5A. When the metal bonding film 8 is lead-free solder, the bonding between the stud bump 4 and the connection pad 5A is solder bonding, and when the metal bonding film 8 is Sn or an Sn alloy containing Sn as a main component, The bonding with the connection pad 5A is an Au—Sn eutectic bonding. The semiconductor circuit module 1 is manufactured through the process A to the process E.

  Next, the operation of the method for manufacturing the semiconductor circuit module 1 according to the first embodiment will be described with reference to FIGS. 4 and 6 to 8.

  The semiconductor circuit module 1 of 1st Embodiment is manufactured by passing through the process E from the process A as mentioned above. In this step B, as shown in FIG. 4E, a connection pad 5A having both side walls 6A is formed, and the inner width W2 of the both side walls 6A is outside the stud 4a formed on the stud bump 4. It is about the same as the width W1. Then, in step D, as shown in FIG. 6, the stud 4a of the stud bump 4 is press-inserted inside the both side walls 6A, thereby bringing the side surface 4b of the stud 4a into close contact with the inner side surfaces 6Aa of the both side walls 6A. ing.

  In the first embodiment, since the stud bump 4 is formed using Au in the process A, in the process B, the inner width W2 of the both side walls 6A is larger than the outer width W1 of the stud 4a. You may form so that only length may become small or large. At that time, as shown in FIG. 7 or 8, in step D, the outer width W1 of the stud 4a is deformed along the inner side surface 6Aa of the side walls 6A, and the side surface 4b of the stud 4a is changed to the inner side of the side walls 6A. The side surface 6Aa is in close contact.

  That is, the contact between the stud bump 4 and the connection pad 5A is achieved by bringing the side surface 4b of the stud bump 4 into contact with the connection pad 5A, instead of bringing the slight tip surface 4c of the stud bump 4 into contact with the connection pad 5A. The area can be made larger than before. As a result, in step E, since the bonding area between the metal bonding film 8 formed on the surface of the connection pad 5A and the stud bump 4 can be increased, the bonding strength between the stud bump 4 and the connection pad 5A is increased. be able to. Further, since the side surface 4b of the stud 4a is in close contact with the inner side surface 6Aa of the both side walls 6A, even if the film thickness of the metal bonding film 8 cannot be formed as thick as about 3 μm as in the case of electroless plating. The bonding strength between the stud bump 4 and the connection pad 5A can be increased.

  In addition, since the stud bump 4 of the first embodiment is formed using Au or an Au alloy mainly composed of Au, the stud 4a of the stud bump 4 is made larger than that formed using other metals. Can be deformed. Thereby, when the stud 4a is press-inserted inside the both side walls 6A in the process D, the stud 4a is easily deformed in the width direction, and the contact area between the side surface 4b of the stud 4a and the inner side surface 6Aa of the both side walls 6A is increased. Therefore, the bonding strength between the stud bump 4 and the connection pad 5A can be increased. Moreover, since Au is excellent in conductivity, the conductive efficiency between the semiconductor chip 2 and the mounting circuit 3A can be improved.

  Further, as shown in FIG. 6, the front end surface 4c of the stud 4a is formed smoothly in the step A, and the front end surface 4c of the stud 4a is brought into contact with the smooth bottom surface 3Aa surrounded by the side walls 6A in the step D. The stud 4a is pressed and inserted inside the side walls 6A. By bringing the front end surface 4c of the stud 4a into contact with the bottom surface 3Aa, the front end surface 4c of the stud 4a comes into surface contact with the bottom surface 3Aa, and the stud 4a comes into close contact with both side walls 6A from the boundary portion between the both side walls 6A and the bottom surface 3Aa. . Thereby, the contact area between the stud bump 4 and the connection pad 5A can be easily increased.

  As shown in FIG. 6B, these stud bumps 4 and both side walls 6A are bonded via a metal bonding film 8. This metal bonding film 8 is made of lead-free solder or Sn or Sn alloy containing Sn as a main component. It is any one of the bonding materials, and is formed by plating on the surface of the connection pad 5A. When lead-free solder is used as the metal bonding film 8, the side surface 4b of the stud 4a can be brought into close contact with the inner side surface 6Aa of the side walls 6A, so that even if the lead-free solder cannot be plated thickly, the stud The bonding strength between the bump 4 and the connection pad 5A can be increased. Further, when Sn or an Sn alloy containing Sn as a main component is used as the metal bonding film 8, the Au—Sn eutectic bonding can be performed between the stud bump 4 and the connection pad 5 </ b> A using the Au stud bump 4.

  Further, since the stud 4a of the stud bump 4 is formed in a cylindrical shape taking over the shape of the Au wire 20, in order to increase the bonding strength between the stud bump 4 and the connection pad 5A, the concave shape inside the side walls 6A. Is preferably adapted to the outer shape of the stud 4a. Therefore, in the first embodiment, as shown in FIG. 4, the resist film 11A is patterned with two linear grooves 12 serving as the molds of the side walls 6A in step B2, and the two linear grooves are formed in step B3. Both side walls 6 </ b> A are plated inside 12. Since the concave shape of both side walls 6A can be formed in various dimensions and shapes by appropriately changing resist patterning and plating conditions of both side walls 6A, the concave shape of both side walls 6A can be easily formed into the outer shape of stud 4a. Can be adapted.

  That is, according to the manufacturing method of the semiconductor circuit module 1 of the first embodiment, the side surface 4b of the stud 4a of the stud bump 4 is brought into close contact with both side walls 6A of the connection pad 5A, and the contact between the stud bump 4 and the connection pad 5A. Since the area can be increased as compared with the conventional case, the bonding strength between the connection pad 5A and the stud bump 4 is increased, and the semiconductor circuit module 1 in which the poor conduction of the semiconductor chip 2 is unlikely to be produced can be produced. .

  Next, a method for manufacturing the semiconductor circuit module of the second embodiment will be described with reference to FIG. Here, FIG. 9 is a longitudinal cross-sectional view showing the process B of the second embodiment in the order of A to H.

  The semiconductor circuit module of the second embodiment is manufactured through the process A to the process E as in the first embodiment. Of these steps A to E, the other steps except step B are the same as the other corresponding steps in the first embodiment. Also in the process B, the connection pad 5B having both side walls 6B is formed in the same manner as in the process B of the first embodiment, but the process contents are slightly different from those in the first embodiment.

  The process B of the second embodiment includes a new process B6 to a process B11 in order, following the process B1 similar to the first embodiment. In step B1, as shown in FIG. 9A, a seed film 10B is formed on the smooth surface of the mounting circuit 3B.

  In step B6, as shown in FIG. 9B, a resist film 11B is formed on the surface of the seed film 10B, and then one linear groove 13 is patterned. This one straight groove 13 is the same size as the enclosed range at the formation position of both side walls 6B and the formation position of the bottom surface 3Aa surrounded by both side walls 6B, that is, the position surrounded by both side walls 6B (FIG. 9B). , The inner width of one straight groove 13 is formed to be equal to the outer width of both side walls 6B).

  In step B7, as shown in FIG. 9C, the metal bottom film 7 is smoothly formed on the surface of the seed film 10B by plating the seed film 10B exposed from the linear groove 13. The material used for this metal bottom film 7 is the same as the material used for both side walls 6B.

  In step B8, as shown in FIG. 9D, the resist film 11B formed in step B6 is removed. Thereafter, as shown in FIG. 9E, a resist film 11B is formed again on the surface of the mounting circuit 3B and the metal bottom surface film 7 and patterned, so that the linear groove 13 similar to the linear groove 13 formed in the step B6 is formed. Along with the formation of the resist film 11 </ b> B, one resist strip 15 parallel to the linear groove 13 is formed simultaneously with the linear groove 13 in the center of the surface of the metal bottom film 7.

  In step B9, as shown in FIG. 9F, both side walls 6B are formed on the surface of the metal bottom film 7 by plating the metal bottom film 7 exposed from the linear groove 13 after the formation of the resist strips 15. . The material used to form both side walls 6B is the same as that in the first embodiment.

  In step B10, as shown in FIG. 9G, after the formation of both side walls 6B, the resist film 11B and the resist strip 15 are removed with a resist remover. The resist remover is the same as the resist remover used in the first embodiment.

  In step B11, as shown in FIG. 9H, the seed film 10B exposed after the removal of the resist film 11B and the resist strip 15 is removed by ion milling.

  Next, the operation of the manufacturing method of the semiconductor circuit module according to the second embodiment will be described with reference to FIGS. Here, FIG. 10 is a longitudinal sectional view showing the process D of the second embodiment in the order of A and B. FIG.

  The manufacturing method of the semiconductor circuit module of the second embodiment includes steps A to E as in the first embodiment, and step B of the method is different from that of the first embodiment. Here, as shown in FIG. 9C, the metal bottom film 7 is formed on the surface of the mounting circuit 3B in the process B7, and both side walls 6B are formed on the surface of the metal bottom film 7 in the process B9 as shown in FIG. 9F. It is formed. Therefore, the side walls 6B and the metal bottom film 7 can be continuously formed in a concave cross section. As a result, as shown in FIG. 10, in step D, the tip 4c and the side surface 4b of the stud 4a can be brought into contact with the connection pad 5B, so that the contact area between the stud bump 4 and the connection pad 5B can be increased. it can.

  Further, as shown in FIG. 10, if the front end surface 4c of the stud 4a of the stud bump 4 is formed smoothly and both side walls 6B are formed in accordance with the size and shape of the stud 4a, the stud 4a is disposed on both sides. Since it can be adhered to the wall 6B and the metal bottom film 7, the contact area between the stud bump 4 and the metal bonding film 8 can be easily increased. Thereby, since a joining area becomes large, the joining strength of the stud bump 4 and the connection pad 5B can be enlarged.

  Next, a manufacturing method of the semiconductor circuit module of the third embodiment will be described with reference to FIGS. Here, FIG. 11 is a longitudinal cross-sectional view showing the process B for forming the connection pad 5C of the third embodiment in the order of A to E when the metal bottom film 7 is not provided. FIG. 12 is a longitudinal sectional view showing steps B to A in order of forming the connection pad 5C of the third embodiment when the metal bottom film 7 is provided.

  The semiconductor circuit module of the third embodiment is manufactured through the process A to the process E as in the first embodiment and the second embodiment. Here, of the steps A to E, the steps other than the step B are the same as the corresponding steps in the first embodiment. Also, in the process B for forming the side walls 6C, the formation of the connection pads 5C having the side walls 6C on the smooth surface of the mounting circuit 3C is the same as the process B of the first embodiment. On the other hand, the shape of the side walls 6C is different from the shape of the side walls 6C of the first embodiment or the second embodiment, and accordingly, the process B of the third embodiment is performed in the first embodiment or the second embodiment. Slightly different from step B of the embodiment.

  When the metal bottom surface film 7 is not formed on the connection pad 5C as in the second embodiment, the process B of the third embodiment is similar to the process B of the first embodiment. First, as shown in FIGS. 4B and 11A, the process B of the third embodiment is the same as the process B1 (formation of the seed film 10A) and the process B2 (patterning of the linear groove 12) of the first embodiment. Through the steps, the two linear grooves 12 are patterned on the resist film 11A formed on the surface of the mounting circuit 3C.

  Thereafter, as shown in FIG. 11B, before the side walls 6C are formed by plating, the resist film 11A is heated to shrink the upper portion 11Aa of the resist film 11A in the width direction. As a result, the vertical cross section of the two linear grooves 12 changes from a rectangular shape to a trapezoidal shape in which the length of the upper base is longer than the length of the lower base. The trapezoidal shape can be changed depending on the thickness of the resist film 11A and the heating time.

  Then, as shown in FIG. 11C, both side walls 6C are formed by plating in the same manner as in step B3 of the first embodiment. Similar to the vertical cross section of the two straight grooves 12, the vertical cross section of the both side walls 6C formed by plating is a trapezoid in which the length of the upper base is longer than the length of the lower base. After the formation of the plating on both side walls 6C, as shown in FIGS. 11D and 11E, the resist film 11A and the seed film 10A are removed as in the steps B4 and B5 of the first embodiment, and the connection pads Both side walls 6C of 5C are formed.

  On the other hand, when the metal bottom film 7 as in the second embodiment is formed on the connection pad 5C, the process B of the third embodiment is similar to the process B of the second embodiment. First, as shown in FIGS. 9E and 12A, the process B of the third embodiment includes the process B1 (formation of the seed film 10B), the process B6 (patterning of the linear groove 13), and the process of the second embodiment. The two linear grooves 14 are formed in the resist film 11B formed on the surface of the mounting circuit 3C through the same processes as B7 (formation of the metal bottom film 7) and process B8 (formation of the resist strip 15). To do.

  Thereafter, as shown in FIG. 12B, before the side walls 6C are formed by plating, the resist film 11B and the resist strip 15 are heated to shrink the upper portion 11Ba of the resist film 11B and the upper portion 15a of the resist strip 15 in the width direction. As a result, the vertical cross section of the two linear grooves 14 between the single linear groove 13 and the resist strip 15 changes from a rectangular shape to a trapezoidal shape in which the length of the upper base is longer than the length of the lower base.

  Then, as shown in FIG. 12C, both side walls 6C are formed by plating in the same manner as in step B9 of the second embodiment. The vertical cross section of the both side walls 6C formed with plating is a trapezoid in which the length of the upper base is longer than the length of the lower base, like the vertical cross sections of the two linear grooves 14 described above. When the plating on both side walls 6C is finished, as shown in FIGS. 12D and 12E, the removal of the resist film 11B and the resist strip 15 and the removal of the seed film 10B are performed in the same manner as in the steps B10 and B11 of the second embodiment. As a result, the metal bottom film 7 and both side walls 6C of the connection pad 5C are formed.

  Next, the operation of the semiconductor circuit module manufacturing method according to the third embodiment will be described with reference to FIGS. Here, FIG. 13 is a longitudinal sectional view showing the process D (pressure insertion of the stud 4a) of the third embodiment in the order of A and B. FIG.

  As shown in FIGS. 11E and 12E, the longitudinal cross section of both side walls 6C formed through the process B of the third embodiment is formed in a trapezoidal shape in which the length of the upper base is longer than the length of the lower base. Yes. Therefore, in both side walls 6C, the inner width W2 decreases from the lower side to the upper side, and the entrance has a narrow internal shape. As a result, as shown in FIG. 13, when the stud 4a of the stud bump 4 is pressed and inserted into the both side walls 6C of the connection pad 5C in the process D of the third embodiment, the stud 4a is inside the both side walls 6C. According to the shape, the length of the lower base is deformed into a trapezoidal longitudinal section longer than the length of the upper base. Thus, after the stud 4a is pressed and inserted, the stud 4a is sandwiched between the side walls 6C, so that the bonding strength between the stud bump 4 and the connection pad 5C can be increased.

  Further, as shown in FIG. 12E, as in the second embodiment, the contact area between the stud bump 4 and the connection pad 5C can be increased by forming the metal bottom film 7 on the connection pad 5C (FIG. 12E). 10B). Thereby, when the stud bump 4 and the connection pad 5C are bonded by the metal bonding film 8 in the process E, the connection strength between the stud bump 4 and the connection pad 5C is made larger than the connection pad 5C having no metal bottom film 7. be able to.

  Next, a method for manufacturing the semiconductor circuit module of the fourth embodiment will be described with reference to FIGS. Here, FIG. 14 is a longitudinal cross-sectional view showing the process B for forming the connection pad 5D of the fourth embodiment in the order of A to D when the metal bottom film 7 is not provided. FIG. 15 is a longitudinal cross-sectional view showing the process B for forming the connection pad 5D of the fourth embodiment in the order of A to D when the metal bottom film 7 is provided.

  The semiconductor circuit module of the fourth embodiment is manufactured through the process A to the process E as in the first embodiment and the second embodiment. Here, of the steps A to E, the steps other than the step B are the same as the corresponding steps in the first embodiment. Also, in the process B for forming the both side walls 6D, the formation of the connection pad 5D having the both side walls 6D is the same as the process B in the first embodiment. On the other hand, the shape of the side walls 6D is different from the shape of the side walls 6D of the first embodiment or the second embodiment, and accordingly, the process B of the fourth embodiment is performed in the first or second embodiment. Slightly different from step B of the embodiment.

  When the metal bottom film 7 as in the second embodiment is not formed on the connection pad 5D, the process B of the fourth embodiment is similar to the process B of the first embodiment. First, as shown in FIGS. 4B and 14A, the process B of the fourth embodiment is the same as the process B1 (formation of the seed film 10A) and the process B2 (patterning of the linear groove 12) of the first embodiment. Through the steps, the two linear grooves 12 are patterned in the resist film 11A formed on the surface of the mounting circuit 3D.

  Thereafter, similarly to the process B3 of the first embodiment, the formation of plating on both side walls 6D is started on the surface of the seed film 10A. However, in the fourth embodiment, as shown in FIG. 14B, both side walls 6D are grown by plating until the upper surface 11Ab of the resist film 11A is partially covered. Thereby, the bulging part 9 of the cross-sectional shape of the mushroom which extends inward (and the outer side) of the both side walls 6D above the both side walls 6D is formed.

  After the formation of the plating on both side walls 6D, as shown in FIGS. 14C and 14D, the resist film 11A and the seed film 10A are removed in the same manner as in Steps B4 and B5 of the first embodiment, and the connection pads are removed. 5D side walls 6D are formed.

  On the other hand, when forming the metal bottom film 7 as in the second embodiment on the connection pad 5D, the process B of the fourth embodiment is similar to the process B of the second embodiment. First, as shown in FIGS. 9E and 15A, the process B of the fourth embodiment includes a process B1 (formation of the seed film 10B), a process B6 (patterning of the linear groove 13), and a process of the second embodiment. The two linear grooves 14 are formed in the resist film 11B formed on the surface of the mounting circuit 3D through the same processes as B7 (formation of the metal bottom film 7) and process B8 (formation of the resist strip 15). To do.

  Thereafter, similarly to the process B9 of the second embodiment, the formation of plating on both side walls 6D on the surface of the metal bottom film 7 is started. However, in the fourth embodiment, as shown in FIG. 15B, the side walls 6D are grown by plating until the upper surface 11Bb of the resist film 11B and the upper surface 15b of the resist strip 15 are partially covered. Thereby, the bulging part 9 of the cross-sectional shape of the mushroom which extends inward (and the outer side) of the both side walls 6D above the both side walls 6D is formed.

  After the formation of the plating on both side walls 6D, as shown in FIGS. 15C and 15D, the removal of the resist film 11B and the resist strip 15 and the removal of the seed film 10B are performed in the same manner as in the processes B10 and B11 of the second embodiment. As a result, both side walls 6D of the connection pad 5D are formed.

  Next, the operation of the semiconductor circuit module manufacturing method of the fourth embodiment will be described with reference to FIG. Here, FIG. 16 is a longitudinal sectional view showing the process D (pressure insertion of the stud 4a) of the fourth embodiment in the order of A and B. FIG.

  Both side walls 6D formed through the process B of the fourth embodiment are plated so as to cover the upper surface 11Bb of the resist film 11B and the upper surface 15b of the resist strip 15 as shown in FIGS. 14B and 15B. The bulging portion 9 extends to the inside (and outside) of the side walls 6D above the side walls 6D. Therefore, the longitudinal section is formed in a mushroom shape. From this, as shown in FIG. 14D and FIG. 15D, in both side walls 6D, the inner width W2 is constant from the lower side to the upper side, and the upper side is narrower and the entrance is narrower. become.

  Then, as shown in FIG. 16, when the stud 4a of the stud bump 4 is press-inserted into the both side walls 6D of the connection pad 5D in the process D of the fourth embodiment, the stud 4a has the internal shape of the both side walls 6D. It is deformed so that it can be engaged with. From this, after the stud 4a is pressed and inserted, the bulging portions 9 of the side walls 6D sandwich the stud 4a, so that the bonding strength between the stud bump 4 and the connection pad 5D can be increased. In particular, since the inside of the bulging portion 9 has an inverted L-shaped key shape, the stud 4a can be clamped more strongly than both side walls 6D of the third embodiment.

  Further, as shown in FIG. 15D, as in the second embodiment, the contact area between the stud bump 4 and the connection pad 5D can be increased by forming the metal bottom film 7 on the connection pad 5D (FIG. 15D). 10B). Thereby, when the stud bump 4 and the connection pad 5D are bonded by the metal bonding film 8 in the process E, the connection strength between the stud bump 4 and the connection pad 5D is made larger than the connection pad 5D having no metal bottom film 7. be able to.

  That is, according to the manufacturing method of the semiconductor circuit module of the first to fourth embodiments, the side surface 4b of the stud 4a of the stud bump 4 is brought into close contact with the both side walls 6A to 6D of the connection pads 5A to 5D. Since the contact area with the connection pad 5D can be made larger than before, the bonding strength between the connection pads 5A to 5D and the stud bump 4 is increased, and a semiconductor circuit module that does not easily cause poor conduction of the semiconductor chip is manufactured. There is an effect that can be.

  In addition, this invention is not limited to embodiment mentioned above etc., A various change is possible as needed.

  For example, in step B8 of the second embodiment, in order to align the height from the surface of the mounting circuit 3B to the surface of the resist film 11B and the resist strip 15, one linear groove 13 and one resist strip 15 are formed. Although formed at the same time, in another embodiment, after the step B7, without removing the resist film 11B formed in the step B6, one resist strip 15 is formed inside one linear groove 13. May be. In that case, it is preferable that the material used for the resist strip 15 is the same as the material used for the resist film 11B.

  When an Au surface film is formed as the metal bonding film 8 on the surface of the stud bump 4 and the connection pads 5A to 5D, Au—Au ultrasonic metal bonding may be used as bonding performed in the step E. Of course, when the stud bump 4 and the connection pads 5A to 5D are formed using Au, they can be bonded in the same manner. However, in this case, an Au surface film is formed separately to form the metal bonding film 8. Instead, the surface of the stud bump 4 and the connection pads 5A to 5D is used as the integrally formed metal bonding film 8.

  Further, after forming a stud bump body using the other metal wire instead of the Au wire 20 in the process A in the same manner as the process A described above, the Au film or the Au alloy film described above is plated on the stud bump body. Then, the stud bump 4 may be formed. At this time, since the stud bump 4 may be deformed in the step D, it is preferable to form a thick Au film or Au alloy film formed on the surface.

Transmission plan view showing the connection state in the semiconductor circuit module of the first embodiment 2-2 sectional view of FIG. The longitudinal cross-sectional view which shows process A of 1st Embodiment in order of AD The longitudinal cross-sectional view which shows process B of 1st Embodiment in order of A-E The longitudinal cross-sectional view which shows the process C of 1st Embodiment The longitudinal cross-sectional view which shows the process E of 1st Embodiment in order of A and B in case the inner width of a both-side wall is equivalent to the outer width of a stud The longitudinal cross-sectional view which shows process E of 1st Embodiment in order of A and B in case the inner width of a both-side wall is smaller than the outer width of a stud The longitudinal cross-sectional view which shows process E of 1st Embodiment in order of A and B in case the inner width of a both-side wall is larger than the outer width of a stud The longitudinal cross-sectional view which shows process B of 2nd Embodiment in order of AH The longitudinal cross-sectional view which shows process D of 2nd Embodiment in order of A and B in the case where the inner width of a both-side wall is equivalent to the outer width of a stud The longitudinal cross-sectional view which shows process B of 3rd Embodiment in order of A to E when a connection pad does not have a metal bottom face film The longitudinal cross-sectional view which shows process B of 3rd Embodiment in order of A to E in case a connection pad has a metal bottom film The longitudinal cross-sectional view which shows process D of 3rd Embodiment in order of A and B in case a connection pad does not have a metal bottom face film The longitudinal cross-sectional view which shows process B of 4th Embodiment in order of AD when a connection pad does not have a metal bottom face film The longitudinal cross-sectional view which shows process B of 4th Embodiment in case of a connection pad having a metal bottom face film in order of AD The longitudinal cross-sectional view which shows process D of 4th Embodiment in order of A and B in case a connection pad does not have a metal bottom face film Longitudinal sectional view showing a conventional bonding state when the metal bonding film is sufficiently thick Longitudinal sectional view showing a conventional bonding state when the metal bonding film cannot be formed sufficiently thick

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor circuit module 2 Semiconductor chip 3 Mounting circuit 4 Stud bump 4a Stud 4b Side surface 4c Tip (tip surface)
5A to D Connection pads 6A to 6D Both side walls 6Aa Inner surfaces of both side walls 7 Metal bottom film 8 Metal bonding film 9 Swelling part

Claims (8)

Forming a plurality of stud bumps having the same height on the smooth surface of the semiconductor chip; and
Either before or after the step A, both side walls have an inner width that is approximately the same as the outer width of the stud formed on the stud bump, or an inner width that is smaller or larger than the outer width of the stud by a predetermined length. Forming a connection pad on the smooth surface of the mounting circuit; and
Forming a metal bonding film on the surface of the connection pad as a surface layer of the connection pad; and
After the step C, the stud is press-inserted inside the both side walls, and the side surface or the tip of the stud is pressed against the inner side surface of the both side walls or the smooth bottom surface surrounded by the both side walls, When the inner width of both side walls is different from the outer width of the stud, the stud is deformed in the width direction, and when the inner width of the both side walls is approximately the same as the outer width of the stud, A step D in which the side surface of the stud is closely attached to the inner side surface of the both side walls;
A method of manufacturing a semiconductor circuit module, comprising: a step E of bonding the stud bump to the connection pad by heating the metal bonding film after the step D. 2. The semiconductor circuit module according to claim 1, wherein the stud bump is formed using Au or an Au alloy containing Au as a main component or a metal (including an alloy) having these as a surface film. Production method. 3. The semiconductor circuit module according to claim 2, wherein the metal bonding film is formed by plating using any one material of lead-free solder or Sn or an Sn alloy containing Sn as a main component. Method. The stud is formed with a smooth tip surface,
The said stud is press-inserted inside the said both side wall until the smooth front end surface of the said stud contact | abuts in the said process D to the smooth bottom face enclosed by the said both side walls. 4. A method for manufacturing a semiconductor circuit module according to any one of 3 above. Step B is
Forming a seed film on the smooth surface of the mounting circuit;
Forming a resist film on the surface of the seed film and then patterning two linear grooves at positions where the side walls are formed;
Forming the both side walls by plating the seed film exposed from the two linear grooves; and
A step B4 of removing the resist film after the formation of the both side walls;
5. The method of manufacturing a semiconductor circuit module according to claim 1, further comprising a step B <b> 5 of removing the seed film exposed after the removal of the resist film. Step B is
Forming a seed film on the smooth surface of the mounting circuit;
After forming a resist film on the surface of the seed film, patterning a single linear groove having a size equivalent to the enclosed area at a position surrounded by the both side walls; and
Forming a metal bottom film by plating the seed film exposed from the linear groove; and
Forming a resist strip parallel to the one linear groove at the center of the surface of the metal bottom film;
Forming the both side walls on the surface of the metal bottom film by plating the metal bottom film exposed from the linear groove after the formation of the resist strip; and
Step B10 for removing the resist film and the resist strip after the formation of the side walls;
5. The method of manufacturing a semiconductor circuit module according to claim 1, further comprising: a step B <b> 11 of removing the seed film exposed after the removal of the resist film and the resist strip. . After the step B2 and before the step B3, or after the step B8 and before the step B9, the resist film and the resist strip are heated to form the resist film and the resist strip. By shrinking the upper portion in the width direction, two longitudinal grooves of the two straight grooves formed in the step B2 or two between the one straight groove formed in the step B8 and the resist strip are formed. 7. The method of manufacturing a semiconductor circuit module according to claim 5, further comprising the step of forming a longitudinal section of the straight groove into a trapezoid in which the length of the upper base is longer than the length of the lower base. Method. In the step B3 or the step B9, the both side walls are plated and grown until the upper surface of the resist film in the step B2 or the upper surface of the resist strip in the step B8 is partially covered. The method for manufacturing a semiconductor circuit module according to claim 5, wherein a bulging portion extending inside the wall is formed.

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