JP2830734B2 - Wiring board and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring board in which a semiconductor element is bonded on a board with a resin adhesive, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In FIG.
Reference numerals 10 and 11 denote metal layers constituting the electrodes, respectively Cr and C
u, Ni, and Au. 12 denotes a semiconductor IC, 13 denotes a wiring made of Al of the semiconductor IC, and 14 denotes a bump formed on the semiconductor IC 12 by Au. 15 and 16
Is an ultraviolet curable resin.

In the above configuration, the mounting of the semiconductor IC 12 is performed as follows. First, an ultraviolet curable resin 15 is applied on the glass substrate 1, and then the bump 14 formed on the wiring 13 on the surface of the semiconductor IC 12 and the Au on the glass substrate 1
11 / Ni10 / Cu3 / Cr2 is aligned with the electrode and irradiated with ultraviolet light while pressing the semiconductor IC 12 against the glass substrate 1 to cure the ultraviolet light between the semiconductor IC 12 and the glass substrate 1. The resin 15 is cured. At this time, the ultraviolet curing resin 15 contracts due to the curing. The semiconductor IC 12 is constantly pressed against the glass substrate 1 by this contraction force. As a result, the bump 14 and the electrode of the glass substrate 1 are pressed against each other,
Electrically connected.

[0004]

In the above-mentioned conventional configuration,
The surface of the electrode on the glass substrate 1 becomes a mirror surface due to the good flatness of the surface of the glass substrate 1. Therefore, if the bumps 14 of the semiconductor IC 12 slide on the mirror-finished electrodes before the ultraviolet curing resin 15 is cured, the bumps 14 are formed between the bumps 14 of the semiconductor IC 12 and the electrodes of the glass substrate 1. The ultraviolet curable resin 15 enters into the minute gap, and the adhesiveness between the bump 14 and the electrode is deteriorated by the penetrated ultraviolet curable resin 16, and thus the reliability of the electrical connection is deteriorated.

The present invention solves the above-mentioned conventional problems, and provides a wiring board having high reliability of electrical connection and a method of manufacturing the same.

[0006]

In order to solve the above problems, a wiring board according to the present invention comprises a substrate, an electrode laminated on the substrate, a plating layer laminated on the electrode, together are bonded by a resin adhesive, e Bei a semiconductor element electrically connected via the bumps on the plating layer which is laminated on the electrode, the plating layer or insulator
And a portion of the fine powder protruding above the plating layer.

Further, the manufacturing method includes a first step of forming a thin film of an electrode on a substrate, and immersing the substrate having a thin film of an electrode in a plating solution mixed with a fine powder of an insulator, and forming the thin film on the electrode of the substrate. A second step of forming a plating layer containing fine powder, a third step of electrically connecting the substrate on which the plating layer has been formed and the semiconductor element to each other by interposing bumps on the plating layer; And a fourth step of bonding the semiconductor element with a resin adhesive.

[0008]

According to the above-mentioned structure, the electrode is laminated on a substrate having good surface flatness, and even if the electrode surface is mirror-finished due to the influence of the substrate surface, the plating layer formed on the electrode removes the fine powder. Since a part of the fine powder protrudes on the plating layer, the surface of the plating layer is roughened, and a part of the fine powder protruding on the plating layer digs into the bumps. It is possible to prevent slippage at a contact portion between the plating layer formed thereon and the bump of the semiconductor element. Thus, a fine gap is not generated between the electrode and the bump of the semiconductor element, and no resin flows, so that the electrical connection can be improved.

[0009]

【Example】

Embodiment 1 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a wiring board according to the first embodiment. As shown in FIG. 1, the wiring substrate according to the first embodiment is an electrode formed by laminating a Cr layer 2 and a Cu layer 3 on the glass substrate 1 in this order from the glass substrate 1 side to form a thin film. 16 and an electrode 16 on the electrode 16
It has a plating layer 17 formed by laminating and thinning a Ni layer 10 and an Au layer 11 in this order from the side, and a semiconductor element 12 having an Al wiring 13 bonded to the glass substrate 1 by an ultraviolet curing resin 15. . Further, the Al wiring 13 and the plating layer 17 formed on the electrode 16 are electrically connected via the bumps 14 on the Al wiring 13 so as to electrically connect the Al wiring 13 and the electrode 16 of the semiconductor element 12. Connecting.
Further, the plating layer 17 has the alumina fine powder 9, and a part of the alumina fine powder 9 is projected on the plating layer 17. At this time, the alumina fine powder 9 is contained in the Ni layer 10 in the plating layer 17 and protrudes through the Au layer 11.

The characteristics of the above configuration will be described below. The electrode 16 is formed as a thin film using the glass substrate 1 having a good surface flatness. The surface of the electrode 16 is mirrored by the surface of the glass substrate 1. However, the electrode 16
Since the plating layer 17 forming the fine particles has the alumina fine powder 9 and a part of the alumina fine powder 9 protrudes above the plating layer 17, the surface of the electrode 16 is roughened.

When the bumps 14 and the electrodes 16 are brought into pressure contact with each other, a part of the alumina fine powder 9 projecting on the plating layer 17 bites into the bumps 14. Can be prevented from slipping at the contacting portion. Accordingly, a fine gap is not formed between the electrode 16 and the bump 14 of the semiconductor element 12, and the ultraviolet curable resin 15 does not flow, so that the electrical connection can be improved.

Further, the plating layer 17 formed by forming a thin film includes a Cr layer 2, a Cu layer 3, and a Ni layer 1 in this order from the glass substrate 1 side.
0, the Au layer 11 is laminated, and especially the Ni layer 10
Since it is laminated between the layer 3 and the Au layer 11, it is effective as a reaction preventing layer.

As described above, according to this embodiment, since the plating layer 17 forming the electrode 16 has the alumina fine powder 9 and a part of the alumina fine powder 9 protrudes above the plating layer, Since the surface is roughened and the alumina fine powder 9 bites into the bumps 14, slippage does not occur between the two, and as a result, there is no inflow of the ultraviolet curable resin 15 and the electrical connection can be improved. .

The plating layer 17 formed by forming a thin film includes a Cr layer 2, a Cu layer 3, and a Ni layer 1 in this order from the glass substrate 1 side.
Although the Au layer 11 is laminated, a metal such as Al, Cu, or Cr may be used instead of the Ni layer 10.

In this embodiment, alumina is used as the fine powder. However, metal oxide such as Ta205, glass, resin such as polyethylene, and insulator such as boron nitride may be used. In particular, metal oxides have good adhesion to ultraviolet-curable resins, and insulators have good adhesion to resins in general.

(Embodiment 2) Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

FIGS. 2A to 2E are process diagrams showing the steps of manufacturing the wiring board according to the present invention described in the first embodiment.

As shown in FIG. 2A, a Cr layer 2 is formed on a glass substrate 1 by sputtering or electron beam evaporation to a thickness of 0.05%.
2 μm and a Cu layer 3 are sequentially formed as a 1 μm thin film.
As shown in (b), the Cr layer 2 and the Cu layer 3 are formed in a desired pattern by photoetching.

Next, as shown in FIG.
The glass substrate 1 on which the electrodes 16 are laminated is immersed in a Ni plating liquid 8 mixed with about m of alumina fine powder 9. Thereafter, a gas such as air, nitrogen or argon flows into the Ni plating liquid 8 from the introduction pipe 5 and is ejected from the hole 6 to form a bubble 7. Then, the Ni layer 10 containing the alumina fine powder 9 is formed by plating on the electrode 16 of the glass substrate 1 while stirring the Ni plating solution 8 by the bubbles 7. At this time, it is desirable that the alumina fine powder 9 be contained in an amount of 10 to 150 g per liter of the Ni plating solution 8. Also,
The particle size of the alumina fine powder 9 is desirably about 0.1 μm to 3 μm.

Then, on the Ni layer 10 formed by plating,
0.1 μm of metal such as Au layer 11 is formed by electroless plating or the like.
m. At this time, the thickness of the Au layer 11 is
The thickness is such that a part of the alumina fine powder 9 contained in the metal layer 0 protrudes on the Au layer 11 formed by plating.

In this manner, as shown in FIG. 2D, an electrode 16 composed of the Cr layer 2 and the Cu layer 3 is provided on the glass substrate 1, and a Ni layer containing the alumina fine powder 9 is provided on the electrode 16. The Au layer 11 is laminated on the Ni layer 10, and a part of the alumina fine powder 9 contained in the Ni layer 10 is projected through the Au layer 11.

Thereafter, as shown in FIG. 2E, the glass substrate 1 on which the plating layer 17 is formed is electrically connected to the bumps 14 of the semiconductor element 12 having the Al wiring 13.

Then, the ultraviolet curable resin 1 is applied to the glass substrate 1.
5, the bump 14 and the plating layer 17 on the electrode 16 are aligned, and the semiconductor device 1 having the Al wiring 13 is coated.
Irradiation of ultraviolet rays is performed while pressurizing the glass substrate 2 against the glass substrate 1. As a result, the applied ultraviolet curable resin 15 contracts while curing, and the semiconductor element 12 is constantly pressed against the glass substrate 1 by this contraction force, and the glass substrate 1 and the semiconductor element 12 are bonded.

According to the above configuration, since a part of the alumina fine powder 9 contained in the Ni layer 10 protrudes on the plating layer 17, it is possible to obtain a wiring board that can bite into the bump 14 and make good connection. it can.

The alumina fine powder 9 contains 1 liter of N
It is desirable that the i-plating liquid 8 contains 10 to 150 g. This is because when the amount of the alumina fine powder 9 in the Ni plating solution 8 is small, a part of the alumina fine powder 9
The reason for this is that the ratio of the protrusions on the upper surface 7 decreases, and the slip between the plating layer 17 and the bumps 14 easily occurs. On the other hand, N
When the amount of the alumina fine powder 9 in the i-plating solution 8 is too large, the proportion of a part of the alumina fine powder 9 protruding on the plating layer 17 increases, and the alumina, which is an insulator, causes the plating layer 17 and the bumps 14 to protrude. This is because the connection resistance between them increases.

Further, the particle size of the alumina fine powder 9 is set to 0.1.
1 μm to 3 μm is desirable. This is alumina fine powder 9
When the particle size is smaller than 0.1 μm, the activity of alumina increases and the decomposition of the plating solution is accelerated, and the life is extremely shortened. When the particle size is larger than 3 μm, the size of the alumina fine powder 9 protruding on the plating layer 17 is reduced. Is too large, and the connection resistance becomes large.

In addition, stirring with a gas such as air or nitrogen is N
This has the effect of preventing the deterioration of the plating solution due to the Ni in the i-plating solution 8 adhering to the alumina.

In this embodiment, Cu / Cr is used as the metal forming the electrode 16, but Al, Au, N
As long as it is a material that can be formed by a vapor deposition process or sputtering, such as i, Cu / Ni, Au / Pd / Au, there is no particular limitation on the number of layers, the materials and their combinations, or the thicknesses thereof are not limited. Absent.

As described above, according to the present embodiment, it is possible to provide the method for manufacturing the wiring board according to the first embodiment.

[0031]

As described above, according to the present invention, electrodes are laminated using a substrate having a good surface flatness, and even if the electrode surface is mirror-finished due to the influence of the surface of the substrate, it can be formed on the electrodes. Since the plating layer to be formed has fine powder and a part of the fine powder protrudes on the plating layer, the surface of the plating layer is roughened and a part of the fine powder protruding on the plating layer is formed. Penetrates into the bumps, so that it is possible to prevent slippage at the contact portions between the plating layers formed on the electrodes and the bumps of the semiconductor element. Thus, a fine gap is not generated between the electrode and the semiconductor element, no resin flows, and the electrical connection can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a wiring board of the present invention.

FIG. 2 is a process diagram showing a manufacturing process of the wiring board of the present invention.

FIG. 3 is a cross-sectional view of a conventional wiring board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Cr layer 3 Cu layer 9 Alumina fine powder 10 Ni layer 11 Au layer 12 Semiconductor element 13 Al wiring 14 Bump 15 Ultraviolet curing resin 16 Electrode 17 Plating layer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 21/60 311 H01L 21/92

Claims (7)

(57) [Claims] 1. A substrate, an electrode laminated on the substrate,
A plating layer laminated on the electrode, and a semiconductor element bonded to the substrate with a resin adhesive and electrically connected via bumps on the plating layer laminated on the electrode. Bei example, the plating layer wiring board which projects a fine powder made of an insulating material, and a portion of powder the pulverized on the plating layer. 2. The wiring board according to claim 1, wherein the fine powder is alumina. 3. The wiring board according to claim 1, wherein the plating layer is an upper layer and a lower layer, the lower layer is a Ni plating layer, and the upper layer is a Au plating layer. 4. A first step of stacking an electrode on the substrate, an insulating
A second step of immersing the substrate on which the electrodes are laminated in a plating solution mixed with a fine powder of an object to form a plating layer containing the fine powder on the electrodes of the substrate; and forming the plating layer on the electrodes. A third step of electrically connecting the semiconductor element to the semiconductor element by interposing a bump on the plating layer; and a fourth step of bonding the substrate and the semiconductor element with a resin adhesive. Production method. 5. The method according to claim 5, further comprising: immersing the substrate on which the electrodes are laminated in a plating solution mixed with fine powder, flowing a gas into the plating solution, and stirring the plating solution while stirring the plating solution. 5. The method according to claim 4, wherein a step of forming a plating layer containing fine powder on the electrode is performed. 6. The method according to claim 4, wherein the plating solution is a Ni plating solution, and the fine powder mixed in the plating solution is alumina. 7. The method of manufacturing a wiring board according to claim 6, wherein the weight of the fine alumina powder mixed into the Ni plating solution is 10 to 150 g per liter of the Ni plating solution.