JP4286640B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a semiconductor device and a manufacturing method thereof, and in particular, a structure in which a lead wire formed on a resin tape base material and a bonding bump are formed on the lead wire, and a semiconductor chip is bonded to the lead wire via the bonding bump. The present invention relates to a semiconductor device having a structure and a manufacturing method thereof. Specifically, the present invention relates to a dry film resist laminating method for forming bumps.

  FIG. 5 shows a typical structure of a lead wire and a chip with a metal bump when a semiconductor chip is bonded to a conventional general flexible substrate tape by flip chip bonding. As shown in FIG. 5, this COF structure has a structure in which a lead wire 15 facing a metal pad on a chip 12 is formed on a resin tape substrate 14. The COF structure of FIG. 5 has no device holes.

  In this COF structure, only a lead wire (material: Cu, Au, Sn, etc.) 15 is formed on the resin tape substrate 14. Metal bumps (material: Au, Cu, etc.) 11 for bonding the chip 12 are formed on the metal pads of the electrodes of the chip 12 facing each other. In this state, the lead wire 15 and the chip 12 are generally aligned and joined by heating, pressing, or the like. That is, the bonding bumps 11 are formed on the chip 12 side, and only the lead wires 15 are formed on the resin tape base material 14 side. 13 is a sealing resin.

  However, in the method in which the chip 12 on which the metal bumps 11 are formed is aligned with the lead wire 15 on the resin tape base material 14 and then joined, accurate alignment is required twice. The first requirement is mask alignment accuracy when forming the metal bumps 11 on the electrodes on the chip 12. The second is the alignment of the lead wire 15 and the metal bump 11, and this requires high accuracy. As a result, when the positional accuracy of both is poor, the metal bumps 11 are also detached from the lead wires 15 and normal bonding cannot be established.

There are no previously filed patents related to the present invention. In Patent Document 1, a metal foil (copper foil or the like) is pasted on a resin tape substrate, a mask corresponding to a pattern is formed on a lead wiring, and then only the underlying metal foil is etched to form a wiring pattern. The method is introduced.
JP2003-37137

  Therefore, a method has been considered in which bumps are formed on the lead wire side and semiconductor chips are bonded.

  According to this method, compared to the conventional general bonding of a chip on which a metal bump is formed and a lead on a tape substrate, the first alignment accuracy described above is not necessary and the positional accuracy of bump formation is eliminated. Need not be highly accurate. In addition, there are effects such as a reduction in lead time, a reduction in manufacturing cost, and elimination of misalignment between the lead wire and the bump.

  However, when bumps are formed on the lead wires formed on the resin tape base material, after forming the lead wires, the bumps are piled up again, but the bump forming mask is formed on the lead wires. Need to laminate. In that case, when the mask of the plating bump is laminated on the lead wire, the lead wire with the height previously formed becomes an obstacle, and the laminating property between the mask, the resin tape base material and the lead wire is such that there is no lead wire. It becomes a factor which gets worse in comparison. When the laminating property deteriorates, the finish of the bump plating shape, for example, the bump height, width and depth is adversely affected.

  Thus, the problem is how to improve the adhesion of the mask where the unevenness caused by the lead wire is large.

  Specifically, as shown in FIG. 6, when further metal bumps are to be formed on the lead wires 22 on the resin tape substrate 23, the plating resist 21 is again formed on the lead wires 22 previously plated. Must be laminated. Naturally, once the plating is performed, a height difference (step) is generated in the surface of the resin tape substrate by the height of the lead wire 22. Therefore, when the plating resist 21 is laminated by the conventional method, the lead height has to be laminated, and the plating resist has to be newly laminated, which is newly added to the resin tape base material 23 and the lead wire 22. A gap 24 is easily generated between the laminated resist 21 and the resist 21. As a result, the masking accuracy of the resist is poor, and there arises a problem that the plating deviates from a desired size and shape. Further, if there is a gap 24 between the resin tape base material 23 and the lead wire 22 and the bump plating resist 21, the plating solution enters the gap 24, and the plating grows at an unexpected part. Is expected. Therefore, in order to prevent these problems, it is necessary to laminate the plating resist 21 without a gap.

  Therefore, an object of the present invention is to form a bonding bump on a lead wire formed on a resin tape substrate, and in a semiconductor device having a structure in which a semiconductor chip is bonded to the lead wire via the bonding bump, the laminating property is deteriorated. The problem is solved and the step (lead height) after the first lead wire plating does not affect the resist lamination for the second plating, that is, there is no gap, and the adhesion can be improved. To provide a semiconductor device capable of forming bumps plated to a required size and shape and a method for manufacturing the same.

Semi conductor arrangement of this invention, a resin tape base which leads are formed on the surface, the filler comprising a photosensitive polyimide which is filled between the leads on the resin tape base material, a lead wire and fillers on A bump is formed on a lead wire using a resist to be laminated on a semiconductor chip, and a semiconductor chip having an electrode bonded to the bump.

State method for manufacturing a semi-conductor device, a step of forming a lead wire to the surface of the resin tape base material, a step of filling a filler comprising a photosensitive polyimide between the leads, which is filled in the filling material of the present invention The method includes a step of attaching a resist on the lead wire, a step of forming a bump on the lead wire for bonding to the electrode of the semiconductor chip, and a step of bonding the semiconductor chip to the bump using the resist as a mask.

According to this invention, since the difference in height between the lead wire and the filler is less than the difference in height between the resin tape base material by filling the filler containing the photosensitive polyimide between the lead wires, The adhesiveness of the resist can be improved, and the filler can be left between the lead wires, and there is no need to remove it.

A first reference embodiment will be described with reference to FIG. That is, a high-viscosity liquid or gel filling material 34 is placed on, for example, a polyimide resin tape base material 33 on which the lead wires 32 are formed, and a plating resist, for example, a plating dry film resist 31 is laminated thereon. Thereafter, bumps are formed on the lead wires 32 by plating using the resist 31 as a mask.

  The filling material 34 described above allows the resist 31 to be in close contact with the lead wire 32 without forming a gap.

Thus, in this reference form, in order to reduce the level difference between the lead wire 32 and the surface of the resin tape base material (for example, the substrate) 33, a high-viscosity liquid or gel filling is provided between the lead wires 32. In this method, the material 34 is filled with polyimide or the like. The method for applying the high-viscosity liquid or gel substance 34 onto the tape base material 33 and the method for remaining it are not specified. For the high-viscosity liquid or gel substance 34, a material having good adhesion to the resist 31 needs to be selected. Then, after the bumps are formed, the liquid substance or gel substance 34 is removed after the resist 31 is removed.

A second reference embodiment will be described with reference to FIG. That is, after a resist, for example, a dry film resist 41 for plating is placed on the lead wire 42 formed on the resin tape base material 43, the resist 41 and the tape base material 43 are evacuated to reduce the pressure. The adhesion between the wire 42 and the tape substrate 43 is increased. In addition, the formation of bumps and the like are the same as in the first reference embodiment.

A third embodiment will be described with reference to FIG. That is, the height 54 of the lead wire 52 that causes a gap between the resist, for example, the dry film resist 51 for plating and the tape base 53 does not affect the adhesion between the resist 51 and the tape base 53. It is lowered to the extent. The height of the lead wire 52 is set to a predetermined height when the lead wire is formed, or is reduced after the lead wire is once formed.

Thus, by reducing the thickness of the lead wire 52 and reducing the level difference between the upper surface of the lead wire 52 and the tape base material 53, the adhesion between the resist 51 and the tape base material 53 can be improved. If the height of the lead wire 52 is 15 μm or less, the adhesion of the resist 51 can be improved. Preferably, the actual height is about 8 μm to 8 μm. In addition, the formation of bumps and the like are the same as in the first reference embodiment.

The form of implementation of the invention will be described with reference to FIG. That is, a filler containing a photosensitive polyimide resin 64 is provided between the lead wires 62 formed on the resin tape substrate 64 to reduce the step between the lead 62 and the tape substrate surface height. This same effect as techniques to avoid creating gaps under the resist for example for plating a dry film resist by providing the first reference in the form of a high liquid material 34 viscosity therebetween leads 32 of FIG. 1 I am aiming.

According to this embodiment, in order to reduce the level difference between the lead wire 62 and the tape base material 63, a filler including a photosensitive polyimide resin 64 is provided between the lead wires 62. Although the formation method of the photosensitive polyimide resin 64 on the tape base material 63 is not specified, the difference from the first reference embodiment is that the filler, for example, the photosensitive polyimide resin 64 is used even after the metal bumps are formed. This film is not required to be removed. Therefore, it is necessary to select a material having good adhesion to the plating dry film resist 61 for forming the photosensitive polyimide.

Thus the implementation of the form, by increasing the adhesion between the lead wire or a tape base material and the resist, it is anti-intrusion of the plating solution initially assumed dimensions outside the bumps are formed As a result, each embodiment can contribute to improvement of the dimensional accuracy of the bump.

  The semiconductor device and the manufacturing method thereof according to the present invention improve the adhesion of the laminate of the bump plating mask formed for bonding the semiconductor chip on the lead wire formed on the tape resin substrate so as to face the lead wire. It is useful for semiconductor devices and manufacturing methods thereof.

It is a schematic sectional drawing of the manufacturing process of the semiconductor device of the 1st reference form. It is a schematic sectional drawing of the manufacturing process of the semiconductor device of the 2nd reference form. It is a schematic sectional drawing of the manufacturing process of the semiconductor device of the 3rd reference form. It is a schematic sectional drawing of the manufacturing process of the semiconductor device of embodiment of this invention . It is a schematic sectional drawing of the manufacturing process of the conventional semiconductor device. It is a schematic sectional drawing of the manufacturing process of the semiconductor device for demonstrating a subject.

Explanation of symbols

11 Metal bump 12 Chip 13 Sealing resin 14 Resin tape substrate 15 Lead wire 21 Dry film resist 22 Lead wire 23 Resin tape substrate 31 Dry film resist 32 Lead wire 33 Resin tape substrate 34 Liquid substance 41 Dry film resist 42 Lead Wire 43 Resin tape substrate 51 Dry film resist 52 Lead wire 53 Resin tape substrate 54 Lead wire height 61 Dry film resist 62 Lead wire 63 Resin tape substrate 64 Photosensitive polyimide resin

Claims (2)

Resin tape base material having a lead wire formed on the surface, a filler containing photosensitive polyimide filled between the lead wires on the resin tape base material, and a resist laminated on the lead wire and the filler A semiconductor device comprising: a bump formed on the lead wire using a semiconductor chip; and a semiconductor chip having an electrode bonded to the bump. A step of forming a lead wire on the surface of the resin tape base, a step of filling a filler containing photosensitive polyimide between the lead wires, and affixing a resist on the lead wire in a state filled with the filler A method of manufacturing a semiconductor device, comprising: a step; forming a bump for bonding to an electrode of a semiconductor chip on the lead wire using the resist as a mask; and bonding a semiconductor chip to the bump .

Images