JPS58192688A - Regulation of wire loop shape in wire bonding device - Google Patents

Abstract

PURPOSE:To bend a wire in the operation stage of wire bonding and to regurate a wire loop to a desired shape, by providing a wire shape regulating rod which makes prescribed operation to a wire bonding device. CONSTITUTION:A bonding tool 4, a wire guide 5 and a wire clamp 6 are moved downward while a wire 7 is accompanied, and the wire is pressed onto a semiconductor pellet 2, then an ultrasonic oscillation is impressed thereto to accomplish the 1st bonding. The clamp 6 releases the wire 7, moves upward once and moves horizontally to above a lead post 3 at the 2nd bonding point. The tool 4, the guide 5 and the clamp 6 carrying the wire 7 again are again moved downward and a wire shape regulating rod 8 is advanced below the wire 7 extended to the 1st bonding point and the bottom surface of the tool 4. Said rod is brought into contact with the wire 7 descending together with the tool 4 to bend the wire 7; thereafter, the rod is retreated quickly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention #'iJ@ relates to a wire loop shaping method in a wire bonding apparatus when there is a step between the first bonding point and the second bonding point.

As is well known, in wire bonding, the lower end of the bonding tool KQ is protruded by a wire clamp.
Press the bonding tool to the first bonding point, raise the bonding tool after raising the first bond,
Pull out the wire by moving it to the IM2 bonding point, give the wire a curved shape shown in 11, which is called a loop, and
Place 2 waste 1111.

In general, wire bonding is required in the body board #! There may be a difference between the first bonding point and the second bonding point.

- As an example, if a semiconductor bullet mounted on a heat sink, for example a power transformer/meta, is the first honding point and a lead on the board is the l1A2 honding point, then the fusing force θ of Ai + Bc is the second factor of Fi. Not only is it easy for the unplugged wire to touch the heat 7 link as shown in the figure, but when the wire is wirebotted with the loop closed in order to perform t-mR, the wire may fall down or the wire may be bent during rework, as shown in Figure #A5. This may lead to an accident in which the wire comes into contact with the can or cover being installed.

Conventionally, the method to avoid this is to make the lead hook higher than the A& surface by raising it to the semiconductor pellet as shown in Figure 4, or to leave a certain gap between the heat 7 link and the wire after wire bonding is completed. Separate wire shaping operations have been used to modify the wire loops.

In the conventional method, it is necessary to add post-shaped leads to the board, and the wire honting process becomes G4, which not only causes problems with the groove axis of wire honting, but also when considering automation. There was #ll later.

Taking these circumstances into consideration, the present invention has developed a conventional wire bonding device cV (a wire-fed keychain that performs a predetermined operation).
In general, the wire in wire bonding equipment whose purpose is to bend the wire during excessive movement during wire bonding, and to shape the loose wire into the desired shape after wire bonding. Providing techniques for roof shaping.

An embodiment of the present invention is illustrated in FIGS. 45 to 10 below. Fig. 5 shows the honding tool 4 and wire guide 5 attached to a temporary excavation horn (not shown) at the J111 bonding point. The figure shows a state in which the wire 7 is held by the pipe wire guide 5, and the bonding sole 4 is guided by the wire guide 5, and the bonding sole 4 is extended to the lower surface of the bonding sole 4 to enter the first bonding operation. After hardening the noodles using a method known to those skilled in the art, the bonding tool 4 and the bonding tool 4 are used to perform wire bonding in a predetermined manner.
Wire guide 5 and wire clamp 7°6t - Lower the wire 7 along with the wire 7, as shown in FIG.
The tip of the pellet is pushed out onto the semiconductor pellet 2 by the bonding knoll 4, and ultrasonic vibration is applied to the pellet.

When the first bonding is completed, wire clamp 6#'
After gripping the i-wire 7, the honding tool 4 and wire guide 5 together rise once as shown in FIG. Move to. At this time, since the tip of the wire 7 is bonded onto the half-width bullet 2, the wire 7Vi is completely passed through the wire guide 5 and pulled out from a wire spool (not shown).

Next, as shown in FIG. 9, the wire clamp 7 holding the honding tool 4, wire guide 5 and wire
61tP+ and descending ζ, below the first bonding point and the wire 7 attached to the bottom of the bonding tool 4,
A wire shaping tool 8 having a cross-sectional shape to give the wire 7 a desired bend is brought into contact with the wire 7 descending together with the honting tool 2, and the wire 7 is quickly retracted after the wire 7 is bent.

The timing of the downward approach, stop and retreat of the wire 7 of wire shaping @B and the operation of the honding tool 40a and the entry position of the wire shaping rod 8 are the same as that of the heat sink 1, the first honding point and # I2 is determined in advance by the distance to the Hong Kong point and the desired shape of the wire loop after bonding.

One condition of this embodiment is that the cross section of the wire shaping rod 8 is circular, and the point where it enters below the wire 7 (i1Fi' is located at the center of the wire shaping rod 8 or approximately above the side wall of the lead 5 II of the heat sink 1). , and the high mystery is that the distance between the bottom flange 6 of the bonding tool 4 at the position shown in Figure 71R8 when the bonding tool 4 is raised is t! 1/2,
The timing for the wire shaping rod 8 to enter is determined by the honding tool 4.
The period when
The retraction period is the period when the wire 7 assumes the shape shown in Fig. 9.

Wire 7 or Wire I! When the wire 7 is bent by the shape wire 8, even when the wire 7 is lowered, the shape of the wire 7 remains the bent shape t from the wire shaping stretcher 8r and the bonding tool remains intact. 4 and K) descend.

That is, after the wire 7 is bent by the wire shaping rod 8, bending of the wire 7 due to the lowering of the bonding tool 4 occurs mainly at a position 10 near the wire 1 bonding.

As shown in Fig. 10, the wire 7 is pressed onto the lead 5 by the honding tool 4, and
When a motion is applied to the wire 2, it takes on the shape of a drop on the top surface of the wire 7Fi heat link 1 and the hook wall.

With the completion of the llA2 Honda soldering, the 11th position ll1lTK4ψ of the wire 7 is cut using a cutter 9 using a method not shown.
Insert the wire 7 in half a line with the wire clamp flow and on the force side that moves away from the bonding tool 4.
After pulling and cutting, complete one cycle of MK return D wire bonding as shown in Figure 45.

As explained above, according to the wire loop shaping method according to the present invention, it is possible to shape the bonded wire loop into a desired shape even when there is a step between the first bonding point and the second bonding point. This makes it possible to avoid accidents such as the wire coming into contact with a part of the board including the heat sink, or the can or cover that will be enclosed in the post-cutting root.

In addition, in order to shape the wire loop without adding extra time to the operation of conventional wire bonding, bonding #ItV (automation is possible without the need for other process steps and time for modifying the wire). Not only that, but
It has the advantage of improving the pseudo-III nature of wire honing.

[Brief explanation of drawings]

Figures 1 to 4 are explanatory diagrams showing the wire shape according to the conventional wire bonding method ν (Fig. It is an explanatory diagram of the operation. Fig. 1 Voice 2 Fig. 5 Fig. 6 also Fig. 7 Fig. 8 Kasumi Fig. 9 Fig. 10

Claims (1)

[Claims] In a wire honting device where there is a step between the first bonding point and the #42 bonding point, the bonding sole that has completed the J@1 bonding process catches the overroot that moves to the second bonding point while passing the wire, and the Enter and stop the wire shaping bell below the wire extended to -1 at the lower end of the bonding tool, and move it along with the bonding tool to the 'FI4' position.
Contact the wire, bend it, and remove it, then connect the 11I distribution 1 bonding point and the ^01 2nd bonding point by connecting the 111I distribution 1 bonding point and the ^01 2nd bonding point by making a second bonding of the Japanese wire. Wire Lou 1 Shaping 77SL- in the INK Wire Honda/Da INK that makes the hair look purple.