JPH0587948U - Wire bonding equipment - Google Patents

Abstract

(57) [Summary] [Purpose] To reliably and efficiently perform wire bonding on a warped substrate such as a glass epoxy substrate. [Structure] The substrate 1 on which a semiconductor chip 23 is mounted is placed on a carrier rail 2, and the semiconductor chip 23 is mounted by a capillary 4.
The electrode and the lead portion 18 of the substrate 1 are wire-bonded. At the time of wire bonding, the pressing member 10 having the elastic pad 9 is lowered to press the substrate 1 so that the substrate 1 is brought into close contact with the transport rail 2 and the substrate 1 is prevented from being lifted due to warpage.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a wire bonding device.

[0002]

[Prior Art]

 FIG. 6 shows a conventional wire bonding apparatus disclosed in Japanese Patent Laid-Open No. 2-206143. In the figure, reference numeral 61 denotes a transducer, which includes a horn 2 and a piezoelectric element 63 attached to the rear end of the horn 2, and a capillary 64 is attached to the front end of the horn 2. A bonding wire 67 such as a gold wire is inserted through the capillary 64, and the insertion tip of the bonding wire 67 faces the lead frame 65 on the transport rail (not shown) and the semiconductor chip 66 mounted on the lead frame 65. There is.

To perform wire bonding with the above configuration, a melting ball 69 is formed at the lower end portion of the bonding wire 67 by electric spark of a torch electrode (not shown), and in this state, the capillary 64 causes the predetermined electrode of the semiconductor chip 66 to be formed. It moves up and the molten ball 69 is pressed against the same electrode. Then, the ultrasonic wave oscillation of the transducer exposes the fresh surface of the molten ball and press-bonds it to the electrode of the semiconductor chip 66 for the first bonding. Next, the capillaries 64 move up, the transport rail moves the lead frame 66 in the XY directions, and positions the corresponding electrodes of the lead frame 65 directly below the capillaries 64. Then, the lower end of the capillary 64 is brought into contact with the electrode of the lead frame 65, and the second bonding is performed.

[0004]

[Problems to be solved by the device]

 By the way, in recent years, wire bonding has been performed on a hard substrate such as ceramics or a glass epoxy substrate in place of the lead frame. Since these substrates, especially glass epoxy substrates, have large warpage, they easily float randomly from the transport rail. When the second bonding is performed in this floating state, the bonding strength is insufficient due to the non-adhesion of the bonding wire and the insufficient heating of the substrate, and reliable wire bonding cannot be performed. Therefore, in wire bonding to these substrates, as shown in FIG. 7, the clamp mask 70 is brought into contact with the substrate 71 and the substrate 71 is brought into close contact with the transport rail by the clamping force.

However, the clamp mask 70 is dedicated to the pattern of the substrate, and if the model and size of the substrate are different, it is necessary to select a dedicated clamp mask. Therefore, replacement of the clamp mask and adjustment of its attachment are troublesome, and there is a problem that the efficiency of wire bonding deteriorates.

The present invention has been made in consideration of the above circumstances, and the substrate can be brought into close contact with the transfer rail without using a clamp mask, and thus wire bonding with improved reliability can be efficiently performed. It is an object of the present invention to provide a wire bonding device that can be used.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention is provided with a pressing member for pressing the substrate on the transport rail, and the pressing member is moved in the substrate direction by the driving member.

[0008]

[Action]

 In the above configuration, the pressing member presses the substrate against the transport rail, so that the substrate comes into close contact with the transport rail. Therefore, the bonding can be surely and promptly performed without the bonding wire sticking or lack of strength.

[0009]

First Embodiment FIGS. 1 and 2 show a first embodiment of the present invention, in which a head 6 is provided above a transport rail 2 on which a substrate 1 made of a hard substrate such as ceramics or a glass epoxy substrate is placed. ing. The transport rail 2 has a temperature control function inside, and transports the substrate 1 while heating it. On the substrate 1, a lead portion 18 made of a conductive material is patterned and a semiconductor chip 23 such as a bare chip is mounted. Reference numeral 3 is a transducer, and a capillary 4 into which a bonding wire 5 is inserted hangs down from the tip thereof.

A pair of parallel support plates 7 are attached to the head 6, and a prismatic pressure member 10 is sandwiched between the support plates 7 and hangs down. As shown in FIG. 2, the support plate 7 and the pressure member 10 are assembled by forming a vertically long slot 11 in the pressure member 10 and a similar guide hole 13 in the support plate 7. The guide plate 12 is inserted into the elongated hole 11 and the guide hole 13 (see FIG. 1). An elastic pad 9 such as silicon rubber is adhered to the lower end surface of the pressing member 10.

A rotary drive unit 14 is attached to one of the support plates 7. A rotary shaft 15 (see FIG. 2) of the rotary drive unit 14 penetrates through the plate 7, and a gear portion is provided in the penetrating portion. 16 is attached. Further, as shown in FIG. 2, the pressure member 10 is provided with a rack 8 that meshes with the gear 16.

In the above structure, during wire bonding, the rotation driving unit 14 is driven to rotate the toothed wheel 16, which causes the pressing member 10 to descend. By this lowering, the elastic pad 9 on the lower surface of the pressing member 10 presses the substrate 1. The pressing portion is the substrate portion near the second bonding, and the substrate 1 is brought into close contact with the transport rail 2 by this, so that the substrate 1 is not lifted and the substrate 1 is heated well. Therefore, the bonding wire can be reliably bonded and reliability is improved. Further, since the pressing member 10 can be applied to various substrates 1 as it is, it is not necessary to replace the pressing member 10 and it is possible to perform efficient wire bonding. In particular, in this embodiment, since the shape of the pressing member 10 can be made small, it can be favorably applied to bonding to a small semiconductor chip.

[0013]

Second Embodiment FIG. 3 shows a second embodiment of the present invention, and the same elements as in the first embodiment are designated by the same reference numerals. In the second embodiment, a rectangular-shaped press fitting 17 is attached to the lower end of the press member 10, and an elastic pad 9 such as silicon rubber is bonded to the lower surface of the press fitting 17. The pressure fitting 17 and the elastic pad 9 are parallel to the direction in which the lead portions 18 formed on the substrate 1 are arranged, and the lower surface of the pressure fitting 17 is parallel to the transport rail (not shown). ing.

Even in such a configuration, the same operation as in the first embodiment is performed, but since the area for pressing the substrate 1 is large, there is an advantage that it can be applied to a multi-pin bare chip or a substrate with a large warp.

[0015]

Third Embodiment FIGS. 4 and 5 show a third embodiment of the present invention, in which the same elements as in the first embodiment are designated by the same reference numerals. In the third embodiment, a bracket 19 is attached to the lower end of the pressure member 10, and a pressure pin 21 is detachably attached to the bracket 19. As shown in FIG. 5, a plurality of screw holes 20 are arranged in the vertical and horizontal directions on the lower surface of the placket 19, and the pressure pin 21 is screwed into all the screw holes 20 or only the necessary screw holes 20. It An elastic pad 9 made of silicon rubber is bonded to the lower end surface of each pressure pin 21.

In this embodiment as well, the same operation as in Embodiment 1 is carried out, but by changing the mounting position of the pressure pin 21, the pressing position on the substrate can be set arbitrarily, so that high-density mounting is possible. It has the advantage that it can also be applied to wire bonding.

[0017]

[Effect of the device]

 As described above, according to the present invention, since the substrate is pressed onto the carrier rail by the pressing member so as to be in close contact, reliable and reliable wire bonding can be performed, and a clamp mask used for each substrate model is unnecessary. It enables efficient wire bonding.

[Brief description of drawings]

FIG. 1 is a perspective view of a first embodiment of the present invention.

FIG. 2 is a partial side view of the first embodiment.

FIG. 3 is a perspective view of a second embodiment of the present invention.

FIG. 4 is a perspective view of a third embodiment of the present invention.

FIG. 5 is a bottom view of the third embodiment.

FIG. 6 is a side view of a conventional device.

FIG. 7 is a side view of another conventional device.

[Explanation of symbols]

 1 Substrate 2 Conveyor Rail 4 Capillary 5 Bonding Wire 10 Pressure Member 14 Rotation Drive Unit 23 Semiconductor Chip

Claims (1)

[Scope of utility model registration request] 1. In a device for wire-bonding a substrate mounted on a transport rail and a semiconductor chip mounted on the substrate by a capillary, a pressing member for pressing the substrate onto the transport rail, A wire bonding apparatus, comprising: a driving member that moves the pressing member toward the substrate.