JPH0448739A - Wire bonding method - Google Patents

Abstract

PURPOSE:To eliminate a short-circuit due to a suspended loop, a bent loop by aligning and bundling wires and supplying them into an interval between electrodes, simultaneously bonding them, and bonding the electrodes of a semiconductor chip and the electrode of a board such as a lead frame, etc., at the sides of the wires. CONSTITUTION:The end sides of wires 12 aligned, bundled and supplied by a bundling and supplying apparatus 8 having a primary bundling unit 3 for feeding the wires 12 from a reel 1 supported to a reel shaft 2 and having guide grooves corresponding to the diameter of the wire 12, an aligner 4, a secondary bundling unit 5, an aligner 6 and a feeding guide 7, are simultaneously bonded to electrodes 15 on a semiconductor chip secured on a board 13 of a lead frame supplied by a board supplying unit 9 by an ultrasonic bonding unit 10. Similarly, the board 13 is sequentially turned by 90 deg. with respect to the other three sides, and the board 11 bonded at the four sides is obtained.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a method for manufacturing semiconductor devices, etc., by fixing the semiconductor chip to a substrate such as a lead frame, and then connecting the electrodes on the semiconductor chip and the electrodes on the substrate. The present invention relates to a wire bonding method.

(Prior art and its issues) In order to incorporate a semiconductor chip into a package, it is necessary to connect the electrodes of the semiconductor/conductor chip to external lead terminals.This connection method includes Neel-to-rad bonding, ultrasonic bonding, There are thermosonic methods, etc.

In recent years, with the transition from ICs to LSIs and even VLSIs, the number of bonding wires per chip has increased to more than several dozen, and in the conventional connection method, each wire is bonded one by one, making it less efficient. It was bad.

In addition, due to the trend toward ultra-thin devices, there has been a demand for a bonding method that has an ultra-low loop and does not cause edge shorts such as tab shorts or chip shorts due to loop sag, or wire shorts due to loop bending.

(Objective of the Invention) The present invention was made in order to solve the above-mentioned conventional problems, and provides a wire bonding method that has good work efficiency and can be made thinner.

(Structure of the Invention) The technical means of the present invention for solving the above problems is a method of fixing a semiconductor chip to a substrate such as a lead frame and wire bonding between an electrode on the semiconductor chip and an electrode on the substrate. A sufficient number of wires to bond the electrodes on one side of the semiconductor chip are fed out from a number of reels, and after being gradually aligned and focused during the transfer, the focused wires are bonded to the electrodes on one side of the semiconductor chip and the semiconductor chip. Supply it between electrodes on a substrate that are on the same plane, and bond a focusing wire to both electrodes at the same time on the side, or sequentially bond to the electrodes on the substrate following the electrodes of the semiconductor chip. This method is characterized in that the wires of the lead frame and the like are then separated.

(Function) According to the wire bonding method of the present invention configured as described above, the wire is supplied between the two electrodes in an aligned manner, or the wire is supplied to the electrode of the semiconductor chip and then to the electrode on the substrate. Since the wires are supplied, bonding can be done all at once or sequentially, and since the bonding is done on the side of the wire with the electrodes of the semiconductor chip and the electrodes of a substrate such as a lead frame on the same plane, there is no need to form a loop (
Therefore, bonding can be performed without short circuits due to loop sagging or loop bending.

(Example) The details of the present invention will be explained below.

As shown in FIGS. 1 and 2, a wire 12 with a purity of 99.99%, a wire diameter of 50 μm, and made of Au is fed out from 20 reels l supported on the reel shaft 2, and the diameter of the wire 12 is adjusted with SUS material. a primary focusing device 3 with a corresponding guide groove;
The tips of the wires 12 are aligned and focused, with a pitch interval of 0.2 mm and a number of 20 wires 12, which are fed by a focusing and feeding device 8 comprising an alignment device 4, a secondary focusing device 5, an alignment device 6, and a transfer guide 7. The side surfaces were bonded all at once to the electrodes I5 on the semiconductor chip fixed to the substrate 13 of the lead frame supplied by the substrate supply device 9, using the ultrasonic bonding device 10. After that, the semiconductor chip 14 is moved in the wire supply direction to pull out the wire 12, and then the electrode 16 of the substrate 13 of the lead frame and the side surface of the wire are bonded all at once using an ultrasonic bonding device IO.
Thereafter, the wire 12 was clamped and cut by pulling.

Next, the substrates 13 such as lead frames were sequentially rotated 90 degrees on the other three sides in the same manner to obtain a total of 80 bonded substrates 11 on the four sides.

In addition, as shown in FIG. 3, the electrode 15 on the semiconductor chip 14
It will be more efficient if the wire 12 is connected to the electrode 16 on the substrate 13 of the lead frame, and bonding is performed at the same time.

In addition, the substrate 13 such as a lead frame can be either a long strip or a short base material, and in the case of a long length, following bonding on the - side, bonding on the other side is performed as a next step. The wires 12 may be aligned and focused and supplied for bonding. Furthermore,
The direction in which the wires are supplied to the substrate 13 may be either the longitudinal direction or the perpendicular direction. Further, when cutting after bonding is performed by tension in the embodiment, for example, as shown in FIG.
By providing the cut 19 in advance, the wire 12 can be cut more reliably and efficiently.

Furthermore, in this embodiment, the electrodes 15 of the semiconductor chip 14 and the electrodes 16 on the substrate 13 are designed to be equally spaced, and the wires 12 are also parallel.
The interval 6 is wider than the interval between the electrodes of the semiconductor chip 14, so even if they are not parallel, it may be done as appropriate by setting the guide groove 17 of a focusing and aligning device.

Note that the bonding method may be not only known thermocompression bonding, ultrasonic bonding, etc., but also electric resistance welding.

(Effects of the Invention) According to the bonding method of the present invention configured as described above, the wires are supplied aligned and focused at the electrode spacing, and bonding can be performed all at once. Since the bonding is performed on the side surface of the wire, no loops are formed, and therefore bonding can be performed without short circuits due to loop sagging or bending.

[Brief explanation of drawings]

1 and 2 are a front view and a plan view showing wire supply and substrate supply in one embodiment of the present invention, and FIG. 3 is a sectional view showing another bonding method in the present invention. Applicant: Tanaka Kikinzoku Kogyo Co., Ltd.

Claims (1)

[Claims] 1) Fix the semiconductor chip to a substrate such as a lead frame,
In a method of wire bonding between electrodes on a semiconductor chip and electrodes on a substrate, a number of wires sufficient to bond one side of the electrodes on the semiconductor chip are fed out from a number of reels and gradually aligned and focused during transport. After that, the focusing wire is supplied between an electrode on one side of the semiconductor chip and an electrode on a substrate that is on the same plane as the semiconductor chip, and the focusing wire is bonded to both electrodes at the same time on the side, or A wire bonding method characterized by sequentially bonding to electrodes on a semiconductor chip, then to electrodes on a substrate, and then separating the wires.