MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE

Abstract

Improvement in shock-resistant strength of a soldered joint is aimed at, and the variation in the plating film formed on an electrode pad is reduced.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are drawings (FIG. 1A is a schematic plan view and FIG. 1B is a schematic cross-sectional view which goes along a′-a′ line of FIG. 1A) showing the internal structure of the semiconductor device which is Example 1 of the present invention;

FIG. 2 is the schematic cross-sectional view which expanded a part of FIG. 1B;

FIG. 3 is the schematic cross-sectional view which expanded the portion of the electrode pad for wire connection of FIG. 2;

FIG. 4 is the schematic cross-sectional view which expanded the portion of the electrode pad for bump connection of FIG. 2;

FIG. 5 is a schematic plan view of the multi-wiring substrate used for manufacture of the semiconductor device which is Example 1 of the present invention;

FIG. 6 is a schematic cross-sectional view expanding and showing a part of multi-wiring substrate of FIG. 5;

FIG. 7 is the schematic cross-sectional view which expanded a part of FIG. 6;

FIG. 8 is the schematic cross-sectional view which expanded the electrode pad portion for wire connection of FIG. 7;

FIG. 9 is the schematic cross-sectional view which expanded the electrode pad portion for bump connection of FIG. 7;

FIG. 10 is a flow chart which shows the manufacturing process of the semiconductor device which is Example 1 of the present invention;

FIGS. 11 to 15 are schematic cross-sectional views showing the manufacturing process of the semiconductor device which is Example 1 of the present invention;

FIGS. 16A to 16C are drawings (FIGS. 16A to 16C are schematic cross-sectional views in each step) for explaining the first bump forming step in manufacture of the semiconductor device which is Example 1 of the present invention;

FIGS. 17A and 17B are drawings (FIGS. 17A and 17B are schematic cross-sectional views in each step) for explaining the second bump forming step in manufacture of the semiconductor device which is Example 1 of the present invention;

FIG. 18 is a schematic plan view showing the outline structure of the module (electronic device) incorporating the semiconductor device which is Example 1 of the present invention;

FIG. 19 is a schematic cross-sectional view which goes along b′-b′ line of FIG. 18;

FIG. 20 is the schematic cross-sectional view which expanded a part of FIG. 19;

FIG. 21 is the schematic cross-sectional view which expanded a part of FIG. 20;

FIG. 22 is a schematic plan view showing the outline structure of the cellular phone (portable electronic apparatus) incorporating the module of FIG. 18;

FIG. 23 is a drawing for explaining the electrolytic plating method;

FIG. 24 is a profile which shows the impurity concentration profile in Ni film;

FIG. 25 is a drawing showing the thickness of Ni film when fixing plating time in 30 minutes and forming Ni film on conditions of 1-3;

FIG. 26 is the drawing which made the table conditions 1-3 of FIG. 25;

FIGS. 27 and 28 are drawings for explaining the valuation method of impact strength;

FIG. 29 is a drawing showing the relation between the chlorine (Cl) concentration in Ni film, and a substrate warp (impact strength: ppm);

FIG. 30 is a drawing showing the relation between the current density at the time of Ni film formation (A/dm²), and impact strength (ppm);

FIG. 31 is a drawing showing the relation between the current density at the time of Ni film formation (A/dm²), and the chlorine (Cl) concentration in Ni film;

FIG. 32 is a drawing showing the relation between the current density at the time of Ni film formation (A/dm²), and the carbon (C) concentration in Ni film;

FIG. 33 is a drawing showing the relation between the plating time (minute) of Ni film, and the thickness (μm) of Ni film;

FIG. 34 is a drawing showing the relation between the plating time (minute) of Ni film, and current density (A/dm²);

FIG. 35 is a drawing showing the relation between average current density (A/dm²), and the thickness of Ni film (μm);

FIGS. 36A and 36B are drawings (FIG. 36A is a schematic cross-sectional view showing the whole structure, and FIG. 36B is the schematic cross-sectional view which expanded a part of FIG. 36A) showing the internal structure of the semiconductor device which is Example 2 of the present invention;

FIG. 37 is a schematic cross-sectional view showing the outline structure of the BGA type semiconductor device which is Example 3 of the present invention;

FIG. 38 is the schematic cross-sectional view which expanded a part of FIG. 37;

FIG. 39 is a cross-sectional view showing the outline structure of the semiconductor device which is Example 4 of the present invention;

FIG. 40 is the principal part cross-sectional view which expanded a part of FIG. 39;

FIG. 41 is a schematic cross-sectional view showing the outline structure of the SiP type semiconductor device which is Example 5 of the present invention; and

FIG. 42 is the schematic cross-sectional view which expanded a part of FIG. 41.

Claims

1. A manufacturing method of a semiconductor device, comprising a step of: forming a metallic film which uses first metal as a main ingredient by an electrolytic plating method over a surface of an electrode pad;wherein the metallic film forming step includes a step which forms a first layer over a front surface of the electrode pad with a first current density, and a step which forms a second layer over a front surface of the first layer with a second current density higher than the first current density.

2. A manufacturing method of a semiconductor device according to claim 1, wherein the first and the second layers are formed continuously.

3. A manufacturing method of a semiconductor device according to claim 1, wherein the second layer has chlorine concentration lower than the first layer included in a layer.

4. A manufacturing method of a semiconductor device according to claim 1, wherein the first metal is nickel.

5. A manufacturing method of a semiconductor device according to claim 1, comprising a step of: forming Au film over the second layer after the metallic film forming step.

6. A manufacturing method of a semiconductor device according to claim 1, comprising a step of: performing heat treatment and joining a solder material of Pb free composition to the second layer of the metallic film after the metallic film forming step.

7. A manufacturing method of a semiconductor device according to claim 1, comprising a step of: performing heat treatment and forming a solder bump of Pb free composition joined to the second layer of the metallic film after the metallic film forming step.

8. A manufacturing method of a semiconductor device according to claim 1, wherein the electrode pad includes a metallic film which uses Cu as a main ingredient.

9. A manufacturing method of a semiconductor device, comprising the steps of: (a) preparing a wiring substrate which has a main surface and a back surface which are mutually located in an opposite side, and an electrode pad arranged at the back surface, and by which a metallic film which uses first metal as a main ingredient was formed over a front surface of the electrode pad;(b) mounting a semiconductor chip over the main surface of the wiring substrate; and(c) forming a resin sealing body which does resin seal of the semiconductor chip over the main surface of the wiring substrate;whereinthe step (a) includes a step which forms the metallic film by an electrolytic plating method; andthe metallic film forming step includes a step which forms a first layer over a front surface of the electrode pad with a first current density, and a step which forms a second layer over a front surface of the first layer with a second current density higher than the first current density.

10. A manufacturing method of a semiconductor device according to claim 9, wherein the first and the second layers are formed continuously.

11. A manufacturing method of a semiconductor device according to claim 9, wherein the second layer has chlorine concentration lower than the first layer included in a layer.

12. A manufacturing method of a semiconductor device according to claim 9, wherein the first metal is nickel.

13. A manufacturing method of a semiconductor device according to claim 9, wherein the step (a) includes a step which forms Au film over a front surface of the second layer after the metallic film forming step.

14. A manufacturing method of a semiconductor device according to claim 9, wherein after the step (c), lead free solder is melted and a bump joined to the first layer is formed.

15. A manufacturing method of a semiconductor device according to claim 9, wherein the wiring substrate has a protective film which includes an insulating resin film at the main surface and the back surface;the electrode pad is exposed from an opening formed in the protective film; andthe metallic film is formed over a front surface of the electrode pad in the opening.

16. A manufacturing method of a semiconductor device according to claim 9, wherein the first and the second electrode pads include a metallic film which uses Cu as a main ingredient.

17. A manufacturing method of a semiconductor device, comprising the steps of: (a) preparing a wiring substrate which has a main surface and a back surface which are mutually located in an opposite side, a first electrode pad arranged over the main surface, and a second electrode pad arranged over the back surface, and by which a metallic film which uses first metal as a main ingredient was formed over each front surface of the first and the second electrode pads;(b) mounting a semiconductor chip over the main surface of the wiring substrate;(c) electrically connecting an electrode pad of the semiconductor chip, and the first electrode pad of the wiring substrate by a bonding wire; and(d) forming a resin sealing body which does resin seal of the semiconductor chip and the bonding wire over the main surface of the wiring substrate;whereinthe step (a) includes a step which forms the metallic film by an electrolytic plating method; andthe metallic film forming step includes a step which forms a first layer over each front surface of the first and the second electrode pads with a first current density, and a step which forms a second layer over a front surface of the first layer of each with a second current density higher than the first current density.

18. A manufacturing method of a semiconductor device according to claim 17, wherein the first and the second layers are formed continuously.

19. A manufacturing method of a semiconductor device according to claim 17, wherein the second layer has chlorine concentration lower than the first layer included in a layer.

20. A manufacturing method of a semiconductor device according to claim 17, wherein the first metal is nickel.

21. A manufacturing method of a semiconductor device according to claim 17, wherein the step (a) includes a step which forms Au film over a front surface of the second layer after the metallic film forming step; andthe bonding wire is joined to the Au film.

22. A manufacturing method of a semiconductor device according to claim 17, comprising a step of: melting lead free solder material and forming a bump joined to the metallic film over the second electrode pad after the step (d).

23. A manufacturing method of a semiconductor device according to claim 21, wherein the wiring substrate has a first insulating resin film formed over the main surface of the wiring substrate, and a second insulating resin film formed over the back surface of the wiring substrate;the first electrode pad is exposed from a first opening formed in the first insulating resin film;the second electrode pad is exposed from a second opening formed in the second insulating resin film;the metallic film and the Au film over the first electrode pad are formed over the first electrode pad in the first opening; andthe metallic film and the Au film over the second electrode pad are formed over the second electrode pad in the second opening.

24. A manufacturing method of a semiconductor device according to claim 17, wherein the electrode pad includes a metallic film which uses Cu as a main ingredient.