JPH05136143A - Semiconductor device and manufacturing method thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a semiconductor element in which a semiconductor element having a large number of output pins at a fine pitch and an electrode of a circuit board can be easily mounted with high reliability without a short circuit between the electrodes. To aim. [Structure] The electrode portion 1 of the semiconductor element 5 is plated with Au.
Alternatively, a bump electrode 6 containing Ag as a main component is formed, and a bonding alloy layer 7 having a low melting point is provided on the opposite side of the bump electrode 6 from the semiconductor element by plating to connect the semiconductor element and the electrode 9 of the circuit board. At times, the alloy layer for bonding was melted and bonded in a state in which the both were in contact with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor element having fine pitch electrodes and a semiconductor element capable of easily and reliably joining electrodes on a circuit board and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, with the digitization of electronic circuits, many semiconductors having a narrow pitch and a large number of pins have been mounted on a circuit board. For this reason, the semiconductor mounting technology has come to have an important influence on the miniaturization of devices. Conventional semiconductor mounting methods include wire bonding, TA
B, flip chip, etc. are available, but the flip chip mounting method with the highest mounting density is drawing attention. Generally well-known flip chip mounting methods include a solder bump method and a stud bump method, but in any case, the size of the electrode of the semiconductor element is required to be 80 μm or more.

The solder bump method is a method in which a barrier metal layer 2 of Cr, Ti or the like is formed on an electrode 1 of a semiconductor element 5 as shown in FIG. 4, and a solder ball 3 is arranged on the barrier metal layer 2. The connection with the substrate is made by melting the solder balls 3. Next, the stud bump method is a method in which Au ball bumps 4 are formed on the electrodes 1 of the semiconductor element 5 as shown in FIG. In this case, the connection with the circuit board is performed by forming a thermosetting Ag paste or solder cream layer on the electrodes of the circuit board by screen printing or metal mask printing, mounting the semiconductor element with the Au bumps 4, and heating. To connect.

[0004]

However, in the case of the conventional structure, in the case of the solder bump, the sputtering, photolithography and etching steps must be repeated to form the barrier metal layer 2, resulting in high cost and poor yield. It also had the drawback. Further, the solder bump is formed by melting the solder ball 3, but it has a drawback that it is impossible to manufacture a solder ball having a uniform size and the bump height varies greatly. The stud bump method is a low cost and simple method, but the size of ball bonding of wire bond is 70 to 80 μmφ.
Is the smallest, and the size of the electrodes of semiconductor elements will be 40 μm ~
It is said that the size will be 60 μm square, and stud bumps will not be compatible. Further, in order to connect with the circuit board, Ag paste or solder must be printed on the circuit board side using a metal mask, but at present, the electrode pitch is 160 μm. Further, in the case of solder printing, there is a problem that solder balls are easily attached between the electrodes and the reliability is deteriorated. The pin pitch of ICs currently used in video cameras is 500
Although the thickness of μm is the smallest, the difficulty of 160 μm pitch can be easily inferred considering that the yield of soldering is still poor.

The present invention solves the above-mentioned conventional problems, and provides a semiconductor element and a method of manufacturing the same, which can easily and reliably join the electrodes of a semiconductor element having fine pitch electrodes and the electrodes of a circuit board. The purpose is to provide.

[0006]

In order to achieve this object, a semiconductor device of the present invention has a protruding electrode containing Au or Ag as a main component, which is plated on an electrode portion of the semiconductor device. On the surface opposite to the semiconductor element, a bonding alloy layer having a melting point lower than that of the protruding electrodes and the electrodes of the circuit board is formed by plating.

[0007]

With this configuration, since the electrode portion of the semiconductor element has the protruding electrode plated, it is possible to sufficiently cope with fine-pitch electrodes, and also in the connection between the circuit board and the semiconductor element, the electrode Since the bonding agent is formed in advance on the portion by plating, the cross-sectional area of the protruding electrode and the cross-sectional area of the bonding material can be made equal to each other, so that highly accurate connection is possible and reliability is remarkably improved.

[0008]

Embodiment 1 An embodiment of the present invention will be described below with reference to the drawings.

First, as shown in FIG. 2A, the glass substrate 8
A portion corresponding to the position of the electrode portion of the completed semiconductor element is obtained by applying a photoresist 10 onto a substrate on which an electric conductor, for example, a transparent electrode ITO layer 9 is vapor-deposited, so that the thickness after drying is 30 to 50 μm. Drill a hole 11 of about 50 μmφ. Next, the entire substrate 8 is immersed in a plating solution to form a transparent electrode ITO.
Electricity is applied to the layer 9 and, as shown in FIG.
An alloy layer 7 for bonding and a protruding electrode 6 are formed in 1. The metal alloy composition of the joining alloy layer 7 tested this time is shown in (Table 1).

[0010]

[Table 1]

The melting point of the bonding alloy layer 7 is lower than the melting points of the protruding electrodes 6 and the electrodes of the circuit board to be bonded, and is preferably set to a temperature (260 ° C.) or lower at which the current reflow furnace can be used. Has been done. Next, the bump electrode 6 was formed by electroplating containing Au or Ag as a main component. At this time, the plating thickness of each protruding electrode is ± 3μ
It turned out that it can be controlled within m. Next, after removing the photoresist 10 with an etching solution, as shown in FIG.
The semiconductor element 5 is arranged so as to face the protruding electrode 6 formed by plating on the glass substrate 8, and the electrode 1 of the semiconductor element and the protruding electrode 6 are thermocompression bonded. At this time, the bonding strength between the electrode 1 and the protruding electrode 6 is set to be stronger than the bonding strength between the ITO layer 9 and the bonding alloy layer 7. This is easily achievable because ITO generally has poor adhesion to metals. Then, when the semiconductor element 5 is separated from the glass substrate 8, the protruding electrode 6 and the bonding alloy layer 7 are transferred to the semiconductor element 5 as shown in FIG. This semiconductor element is brought into contact with the circuit board to be connected through the bonding alloy layer 7 and the temperature is set to 230 ° C. in nitrogen.
When passing through the peak reflow, the joining alloy layer 7 was melted and it was possible to join to the circuit board at a highly accurate pitch of 100 μm without a short circuit between the protruding electrodes.

(Second Embodiment) Next, a second embodiment of the present invention will be described. The present embodiment is different from the above-described first embodiment in that after a hole 11 is formed in a photoresist 10 formed on a glass substrate 8 as shown in FIG. 2A, first, as shown in FIG. Immerse all in plating solution
Electricity is applied to the TO layer 9 and the Au plating layer 1 is placed in the hole 11.
2. Forming the bonding alloy layer 7 and the protruding electrode 6. The metal alloy composition of the joining alloy layer 7 tested this time is the same as that shown in the above (Table 1), and the bump electrode 6 was also formed by electroplating containing Au or Ag as a main component. It was found that the plating thickness of each protruding electrode at this time can be controlled within ± 3 μm.

Next, after removing the photoresist 10 with an etching solution, as shown in FIG. 6, the semiconductor element 5 is arranged so as to face the protruding electrode 6 formed by plating on the glass substrate 8, and the electrode of the semiconductor element is arranged. 1 and the protruding electrode 6 are thermocompression bonded.
At this time, the bonding strength between the electrode 1 and the bump electrode 6 is set to be stronger than the bonding strength between the ITO layer 9 and the Au plating layer 12. This is easily achievable because ITO generally has poor adhesion to metals. Then, when the semiconductor element 5 is separated from the glass substrate 8, the protruding electrode 6, the bonding alloy layer 7, and the Au plating layer 12 are removed from the semiconductor element 5 as shown in FIG.
Will be transcribed.

The semiconductor element 5 is brought into contact with the circuit board to be connected via the Au plating layer 12 and the temperature is 230 ° C. in nitrogen.
When passing through the peak reflow, the bonding alloy layer 7 melts and the Au plating layer 12 diffuses into the connecting alloy layer 7, so that there is no short circuit between the protruding electrodes 6 and the circuit board is formed on the circuit board at a highly accurate pitch of 100 μm. I was able to join.

In the present embodiment, since the bonding alloy layer 7 is formed after the Au plating layer 12 is formed in the hole 11, the bonding alloy layer 7 is formed as compared with the case where the Au plating layer 12 is not formed in the first embodiment. The plating of the alloy layer 7 grows uniformly.
Therefore, the yield when connecting to the circuit board was remarkably improved as compared with the case of the first embodiment.

[0016]

As described above, according to the present invention, the electrode portion of the semiconductor element is provided with the protruding electrode containing Au or Ag as a main component, and the protruding electrode is provided on the side opposite to the semiconductor element. Since the low melting point bonding alloy layer is arranged, an excellent mounting method can be realized in which the electrodes of the fine pitch semiconductor element and the electrodes of the circuit board can be bonded easily and with high reliability.

In addition, there is a protruding electrode containing Au or Ag as a main component formed by plating on the electrode portion of the semiconductor element,
Further, since the low melting point bonding alloy layer and the Au plating layer are arranged on the upper portion thereof, the electrodes of the fine pitch semiconductor element and the electrodes of the circuit board can be bonded easily and with high reliability, which is excellent. The implementation method can be realized.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a semiconductor device according to a first embodiment of the present invention.

2A and 2B are cross-sectional views showing different manufacturing methods in the first embodiment of the method for manufacturing a semiconductor device of the present invention.

FIG. 3 is a sectional view showing a further different step of the same example.

FIG. 4 is a sectional view of a semiconductor device according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a manufacturing method in a second embodiment of the method for manufacturing a semiconductor device of the present invention.

FIG. 6 is a cross-sectional view showing still another step of the same embodiment.

FIG. 7 is a cross-sectional view showing a conventional example in which a protruding electrode is formed on a semiconductor element.

FIG. 8 is a cross-sectional view showing a conventional example in which a protruding electrode is formed on a semiconductor element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor element electrode 2 Barrier metal layer 3 Solder ball 4 Au ball bump 5 Semiconductor element 6 Projection electrode 7 Bonding alloy layer 8 Glass substrate 9 ITO 10 Photoresist 12 Au plating layer

Claims (4)

[Claims] 1. A semiconductor element having a projection electrode mainly composed of Au or Ag formed by plating on an electrode portion of the semiconductor element, and a melting point formed by plating on a surface of the projection electrode opposite to the semiconductor element has the above-mentioned melting point. A semiconductor element having a bonding alloy layer disposed lower than the protruding electrodes and the electrodes of the circuit board. 2. A photoresist is applied on a substrate, a hole is formed in the photoresist at a position corresponding to an electrode of a predetermined semiconductor element, and a bonding alloy layer and Au or Au on the bonding alloy layer are provided in the hole. Protruding electrodes containing Ag as a main component are formed by plating respectively, and then the photoresist is removed, and then the electrodes of the semiconductor element and the protruding electrodes are superposed and joined by heating and pressurizing, and after the joining, the substrate is formed. A method for manufacturing a semiconductor device, characterized in that the bonding of the bonding alloy layer is separated. 3. A semiconductor element having a projection electrode formed by plating and having Au or Ag as a main component, and a melting point formed by plating on the projection electrode and an electrode of a circuit board. A semiconductor element, wherein a lower bonding alloy layer is disposed, and further, an Au plating layer is disposed on the surface of the bonding alloy layer. 4. A photoresist is applied on a substrate, a hole is formed in the photoresist at a position corresponding to an electrode of a predetermined semiconductor element, an Au plating layer is first formed in the hole, and a bonding alloy is formed thereon. Protruding electrodes containing Au or Ag as a main component are respectively formed on the layer and the bonding alloy layer by plating, and after removing the photoresist, the electrodes of the semiconductor element and the protruding electrodes are superposed and heated and heated. A method of manufacturing a semiconductor element, comprising: pressing and bonding, and separating the bonding between the substrate and the bonding alloy layer after the bonding.