Active solid-state devices (e.g. – transistors – solid-state diode – Combined with electrical contact or lead
Reexamination Certificate
2000-03-28
2003-12-30
Chaudhuri, Olik (Department: 2814)
Active solid-state devices (e.g., transistors, solid-state diode
Combined with electrical contact or lead
C257S735000, C257S736000, C257S739000
Reexamination Certificate
active
06670706
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor device in which an electrical connection is made by bringing a semiconductor pellet having a bump electrode and an interconnect board made by forming a pellet electrode on a resilient insulating substrate into mutual opposition, causing the electrodes to be mutually superposed, and imparting ultrasonic vibration to the electrodes, and to a method for manufacturing such a semiconductor device.
2. Background of the Invention
To improve their portability, there is a desire to make compact electronic circuit devices for video cameras, notebook-size personal computers and the like smaller and lighter, and the achievement of smaller electronic components or electronic components of the same dimensions but a higher level of integration used therein contributes to the achievement of more compact and lightweight electronic circuit devices.
The conventional bonding methods used for manufacturing a semiconductor device according to the present invention will be described as follows:
Cited Reference 1-Japanese Utility Model Publication H2-3629
This reference 1 relates to a supersonic type bonding device for electrically connecting an electrode of a semiconductor pellet mounted on a lead frame with a lead of the lead frame with a fine metal wire.
The present reference 1 provides a bonding device for transmitting supersonic vibrations to a wire bonding capillary arranged on the lead frame transporting path through a horn, characterized in that said horn is arranged at an angle of approximately 45° with respect to the lead frame feeding direction on said transporting path.
When the horn is arranged as described above, the horn extends at an angle of approximately 45° with respect to the lead free ends arranged in parallel and perpendicular to the longitudinal direction of the lead frame. At this angle, supersonic vibrations are applied to the lead free ends at the time of wire bonding, and accordingly, it is easy to uniform the wire bonding strength at the lead free ends, whereby the conventional problem is solved.
Cited Reference 2-Japanese Unexamined Patent Application Publication H3-44051 (Kokai)
This reference 2 relates to the art of bonding. In the case of an assembly of a semiconductor device, as one of wire bonding systems, there is a supersonic-combined thermosonic bonding method. Where inner leads of the lead frame are present in four directions, the connecting strength in the inner lead in the direction of supersonic wave is generally large, whereas in the inner lead arranged at right angles to the supersonic direction, the connecting strength is weaker than the former. As described above, all the inner leads are uneven in connecting strength, lacking in stability of connection.
The reference 2 is intended to uniformize connection strength and improve the yield of wire bonding, by positioning all of the inner lead parts and the island part of a lead frame, on the diagonal lines of a frame, and performing wire bonding with ultrasonic wave. For this reason, the constitution of above reference 2 is as follows:
Each inner lead part of a lead frame is arranged along a diagonal line X connecting the points of intersection of an outer frame and an inner frame. The angle between a line Y passing a tab suspension lead and the diagonal line X is 45°. By applying ultrasonic wave via a bonding tool fixed to the tip of an ultrasonic wave transmission arm, wire bonding is performed while a connector wire is sent out. At this time, unidirectional ultrasonic wave is applied in the same direction to all inner lead parts, so that the irregularity of the connection strength between the inner lead parts is hard to generate
Hence uniform and stable bonding state between a chip and each inner lead part can be obtained.
Cited reference 3-Japanese Unexamined Patent Application Publication H4-335546 (Kokai)
The reference 3 is related to method and apparatus for single point bonding for TAB(Tape Automated Bonding). This method is intended to obtain a stable bonding strength at leads without irregularity even if the widths of the leads are small. For this reason, the constitution is as follows: A rotating mechanism for relatively moving one or both of a bonding tool and leads to incline a vibrating direction of the tool by an ultrasonic wave at a predetermined angle with respect to a longitudinal direction of the leads, is provided. The tool is inclined at a predetermined angle with respect to the vibrating direction to form a device opening, and a carrier tape in which leads are disposed, is conveyed.
Cited Reference 4-Japanese Unexamined Patent Application Publication H7-169875 (Kokai)
This reference 4 relates to a ball-bonding method. The method is intended to obtain a highly reliable connection whereby a semiconductor element and a board are connected and which has a large connective strength, a high allowable current value and a low connective resistance, by connecting the semiconductor element with the board through the solid phase diffusion performed between a bump formed on the semiconductor element and a wiring formed on the board, while mounting facedown the semiconductor element on the board in a short time and with a high mounting density.
Regarding the constitution thereof, in a semiconductor device wherein a semiconductor element mounted facedown on a glass board configuring a flat display or on a ceramic board configuring a thermal head, the semiconductor element is bonded to the board through a solid phase diffusion performed between a bump formed on the semiconductor element and a wiring formed on the board.
FIG. 10
shows an example of a semiconductor device that enables high-density packaging. In this drawing, the reference numeral
1
denotes a semiconductor pellet and, as shown in
FIG. 11
, a large number of bump electrodes
3
are formed in a rectangular frame pattern on a main surface of a semiconductor element (not shown in the drawing) therewithin.
The method for forming the bump electrodes
3
is selected from such methods as a method of plating with a metal such as gold, a method of melting a grain of a meltable alloy, and a method of melting a metal wire inserted into capillary so as to form a metal ball, which is pressed at the bottom end of the capillary as ultrasonic vibration is applied to make a connection, after which the metal wire is pulled away.
The reference numeral
4
denotes an interconnection board, formed by a conductive pattern
6
on an insulating substrate
5
, as shown in FIG.
12
. This conductive pattern
6
is covered by a photoresist film (not shown in the drawing), and windows are formed in the photoresist film so that part of the conductive pattern (rectangular windows shown in the drawing) are exposed at locations corresponding to the bump electrodes
3
of the semiconductor pellet
1
, thereby forming the electrode pads
7
.
The semiconductor pellet
1
and interconnection board
4
are disposed in mutual opposition to one another, so that the bump electrodes
3
and the pad electrodes
7
are superposed and electrically connected.
In order to relieve the stress concentrated on the electrode connection parts by heat generated when the semiconductor device
8
operates and to improve resistance to humidity, if necessary a resin is filled between the semiconductor pellet
1
and the interconnection board
4
.
The method for manufacturing the above-noted semiconductor device
8
is described below. First, the interconnection board
4
is placed on a heated table (not shown in the drawing), with the pad electrodes
7
facing upward.
Next, using a pressing tool into the bottom end of which is built a heater, the semiconductor pellet
1
is vacuum picked, with the bump electrodes facing downward, and moved to the top of the interconnection board
4
.
The bump electrodes
3
are superposed on the pad electrodes
7
, and the heated top surface of the semiconductor pellet
1
is pressed by the pressing tool, so as to press the electrodes
3
and
7
together,
Chaudhuri Olik
Ha Nathan W.
NEC Corporation
LandOfFree
Semiconductor device including a semiconductor pellet having... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Semiconductor device including a semiconductor pellet having..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Semiconductor device including a semiconductor pellet having... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3103058