TWI226692B - Method of making wire interconnection between two conductive pads - Google Patents

Abstract

A method of making a wire interconnection between two conductive pads by a capillary having an inner hole, a middle hole surrounding the inner hole and an outer hole surrounding the middle hole is disclosed. The method includes the steps of forming a ball formed on one end of a wire threaded through the inner hole of the capillary, bonding the ball of the wire to one of the conductive pads to form a ball bond employing the capillary, dispensing a dielectric material from the middle hole of the capillary onto the surface of the ball bond to form a dielectric film covering the ball bond, dispensing a conductive material from the outer hole of the capillary onto the surface of the dielectric film covering the ball bond, moving the capillary while the dielectric material and the conductive material continue to flow from the capillary onto the wire threaded through the inner hole of the capillary thereby forming a loop between the first and the second conductive pads, and making a stitch bond to the second conductive pad to finish the wire interconnection.

Description

1226692

[Technical field to which the invention belongs] The present invention relates to a method for forming a wire interconnection between two conductive pads ^ ^ ^ ○ [Prior art] With the speeding up, integration and packaging of signal transmission of semiconductor devices The miniaturization of the semiconductor device has continuously improved the number of semiconductor devices. Therefore, the distance between bonding wires in semiconductor devices is getting closer and closer. As a result, the bonding wire circuits of semiconductor devices often cause short circuits ( sh〇ri: circuit). In addition, because the interleaving of signals in semiconductor devices is more intense, the undesirable stray resistance, stray capacitance, and stray inductance caused by electromagnetic interference will cause the signal transmitted in the wire to be generated. Noise 'further increases power consumption and heat generation. In order to solve the above problems, a person skilled in the art has plated a dielectric layer and a metal layer on the surface of the bonding wire. Figure 1 shows the semiconductor package structure 100 disclosed in the Republic of China Patent Application No. 0 9 1 1 3 3 2 7 2 filed on November 13, 1991, which includes a substrate 1 1 0, A chip 120, a plurality of wires are connected to 130, and a gel 140. Each wire connection 130 has a central wire 132, a dielectric layer 134, and a metal layer 136, respectively. Each of the wires 132 is respectively bonded to the substrate 110 and the chip 120, each of the dielectric layers 134 is respectively coated on the surface of each of the wires 32, and each of the metal layers 136 is respectively coated on the surface of each of the dielectric layers 134. In the aforementioned patent application, the wire 1 3 2 was formed using a conventional wire bonding technology; the dielectric layer 1 3 4 was formed using a conventional plasma chemical vapor deposition method.

00712.ptd Page 6 1226692 5. Description of the invention (2) nsv method, the dielectric layer is deposited on the surface of the center wire layer ^ #general f 6 is formed by deposition or sputtering, because The method of forming a wire connection taught in the patent application is quite complicated and time-consuming. SUMMARY OF THE INVENTION The main object of the present invention is to provide a novel and method of forming a wire connection between two conductive pads, which can overcome or improve the aforementioned problems of the prior art. The method according to the invention uses a special cap llary to form a wire connection between two conductive pads. The welding tip has an inner hole, an intermediate hole surrounding the inner hole, and an outer hole surrounding the intermediate hole. According to the invention method, the method includes the following steps: forming a sphere (baii) at one end of the wire passing through the hole inside the welding tip; using the welding tip to join the sphere of the wire to the first conductive pad to 1 person 1 b〇nd) ^-The dielectric material is matched from the middle hole of the fresh mouth to the surface connected to ^ = to form a dielectric layer to cover the ball joint; a nozzle and the outer hole are distributed to the cover The ball joint is formed by:, the solder tip and the dielectric material and the conductive material are continued from ^: set = the wire in the hole inside the mouth, thereby forming a line between the ί and 塾, and The wire arc system has a dielectric layer covering the wire and an eight-layer conductive layer covering the dielectric layer. After the wire arc is formed, a stamp bond is formed on the second conductive pad to complete the process. The line is connected. π ^ / a wire connection formed according to the foregoing method, which is used to transmit electronic signals

00712.ptd Page 7 1226692 When the wire system is covered with dielectric interference and the method of reducing the center conduction is used between the aforementioned pads, the shape can be effectively simplified. Detailed description [Embodiment] The resistance value of the layer and the conductive layer, and the borrow line. In addition, a special solder tip is formed to form the dielectric layer and the lead improves productivity. The above and other objects, and the present invention are particularly preferred as follows. This can completely block the electromagnetic interference. Since the wire according to the present invention is connected to two conductive electrical connection layers on the central wire, the characteristics and advantages can be more clearly exemplified, and in accordance with the attached invention, the length is: between the two conductive pads A method of forming a wire interconnect ion. A method for forming a wire connection according to an embodiment of the present invention will be described below with reference to FIGS. 2-7. First, as shown in FIG. 2, a sphere (ba 11) 212 is formed at the end of a wire 210. In detail, the sphere (ba 1 1) 2 1 2 can be sintered at the end of the wire 2 10 by means of electronic ignition or hydrogen flame. The wire 2 1 0 is passed through an inner hole 2 3 2 of a welding tip 2 3 0. The welding tip 230 is a part of a wire drawing machine (not shown). It is worth noting that the welding tip 2 3 0 has a middle hole 2 3 4 surrounding the inner hole 2 3 2 and an outer hole 2 3 6 surrounding the middle hole 2 34. Next, the soldering tip 230 is moved to a target conductive pad by the wire bonding machine. As shown in the figure, in this embodiment, the target conductive pad is a wafer pad 242 on a chip 240, and the other conductive pad is a pad 2 62 on the substrate 260. Next, referring to FIG. 3, using the welding tip 230, the sphere 2 1 2 of the wire 2 1 0 shown in FIG. 2 is bonded to the wafer pad 2 4 2 to form a ball joint (ba 1 1

00712.ptd Page 8 1226692 V. Description of the invention (4) b ο n d) 2 1 4 In detail, it first uses the welding tip 2 3 0 to press the ball 2 1 2 of the wire 2 1 0 shown in FIG. 2 onto the wafer static pad 2 4 2, and then the ball 2 1 2 will cause The wire bonder applies force and applies ultrasonic energy to be squeezed to form the ball bond 214. Next, a dielectric material is distributed from the middle hole 2 3 4 of the welding tip 2 3 0 to the surface of the ball joint 214 to form a dielectric layer 252 (see FIG. 3) covering the ball joint 2 1 4. And a conductive material is delivered from the outer hole 236 of the welding tip 230 to the surface of the dielectric layer 252 covering the ball joint to form a conductive layer 2 54 (see FIG. 3). Referring to FIG. 4 and FIG. 5, after the dielectric material and the conductive material are delivered to the surface of the ball joint 2 1 4, the welding tip 2 3 0 is moved to form a line arc 216 between the wafer pad 242 and the wafer. Between pads 262. Referring to FIG. 4, when the welding tip 2 30 moves upward, the dielectric material continuously flows from the middle hole 2 34 of the welding tip 2 3 0 to extend from the inner hole 2 32 of the welding tip 23 0. On the conductive wire 210, and the conductive material continuously flows from the hole 2 3 6 on the outer side of the welding tip 2 30 to the dielectric material. Next, the solder tip 2 30 is moved toward the pad 2 6 2 to form the wire arc 216 (see FIG. 5), and it has a dielectric layer 252 covering the wire 210 and a conductive layer 254 covering the dielectric. On the electrical layer 252. See FIG. 5 'After the line arc 2 1 6 is formed, continue to move the tip 2 3 0 but stop the dielectric material and the conductive material from flowing out of the tip, thereby forming at the end of the line arc 2 1 6 An exposed portion of the wire 218 that does not cover the dielectric material and the conductive material. ^ Then use the soldering tip 2 3 0 to press the exposed wire portion 2 丨 8 shown in Fig. 5 onto the pad 2 6 2. Then, the exposed wire portion 218 will be forced by the wire machine and

00712.ptd Page 9 1226692 V. Description of the invention (5) The ultrasonic energy is applied to be extruded to form a stamp bond 219 (see Fig. 6). Thereafter, as shown in FIG. 6, the soldering tip 2 3 0 is slightly raised 'and the dielectric material is delivered from the middle hole 234 of the soldering tip 23 to the surface of the imprint joint 219 to form a dielectric layer package. The embossed joint 219 ′ is covered and a conductive material is delivered from the outer hole 236 of the tip 23 to the surface of the dielectric layer covering the embossed joint 219. In this embodiment, conductive material can be continuously distributed from the welding hole 2 3 0 outside hole 2 3 6 until the conductive layer 2 5 2 on the adjacent wire embossed joint 2 1 9 is connected into one piece and connected to a ground terminal. For example, a ground pad (gr 0 undpad) on the substrate, so that the conductive layer 2 5 2 on the wire can be grounded through the ground pad portion of the substrate. Finally, the wire 2 10 is clamped with a wire clamp 2 3 9 and the welding tip 2 3 0 is further raised slightly. Referring to Fig. 7, as the tip 2 30 rises, the wire will break at the weakest point of the sharp edge of the stamped joint 2 1 9. Since the foregoing method uses the solder tip 2 30 and forms a dielectric layer 252 and a conductive layer 254 on the center conductor 2 10 together when forming a wire connected between two conductive pads, the process can be effectively simplified to increase production. rate. A method for forming a wire connection according to another embodiment of the present invention will be described below with reference to FIGS. 2 to 7. First, as shown in FIG. 8, a ball 212 is formed at the end of a wire 210. The welding tip 2 31 is part of a wire drawing machine (not shown). It is worth noting that 'the welding tip 2 31 has a middle hole 2 34 surrounding the inner side hole 2 32. Then, the soldering tip 231 is moved to the wafer pad 242 on a wafer 240 by the wire bonding machine.

00712.ptd Page 10 1226692 5. Description of the invention (6) Next, referring to FIG. 9, using the soldering tip 2 3 1 to join the ball 212 of the wire 210 shown in FIG. 2 to the wafer pad 242 to form a Ball bond (ball bond) 214. Next, a dielectric material is distributed from the middle hole 234 of the welding tip 231 to the surface of the ball joint 214 to form a dielectric layer 252 (see FIG. 9) covering the ball joint 2 1 4. Referring to FIG. 10 and FIG. 11, after the dielectric material is distributed onto the surface of the ball joint 214, the welding tip 231 is moved to form a line arc 2 16 between the wafer pad 242 and the pad 262. Referring to FIG. 10, when the nozzle 231 moves upward, the dielectric material continues to flow from the middle hole 2 3 4 of the welding tip 2 3 1 to extend from the inner hole 2 3 2 of the welding tip 2 3 1 Out of the wires 2 1 0. Next, the solder tip 2 3 1 is moved toward the pad 2 6 2 to form the wire arc 2 1 6 (see FIG. 11), and it has a dielectric layer 252 covering the wire 210. Referring to FIG. 11, after the line arc 2 1 6 is formed, continue to move the welding tip 2 3 1 but stop the dielectric material and the conductive material from flowing out of the welding tip, thereby at the end of the line arc 2 1 6 An exposed wire portion 2 1 8 is formed which does not cover the dielectric material and the conductive material. Next, using the welding tip 2 3 1 to press the exposed part 2 1 8 of the wire shown in FIG. 11 onto the pad 26 2, and then the exposed part 218 of the wire will be subjected to the force of the wire bonder and the ultrasonic energy. It is extruded to form a stitch bond 219 (see FIG. 12). Thereafter, as shown in FIG. 12, the soldering tip 231 is slightly raised, and a dielectric material is distributed from the middle hole 234 of the soldering tip 231 to the surface of the imprint joint 2 1 9 to form a dielectric layer coating. This imprint joint 219. Finally, the wire 210 is clamped with a wire clamp 239 and further

00712.ptd Page 11 1226692 V. Description of the invention (7) Step 2 raise the welding tip 2 3 1 slightly. Referring to FIG. 13, as the tip 2 3 1 rises, the wire will break at the weakest point of the sharp edge of the embossed joint 2 1 9. Because the aforementioned method uses the tip 2 3 1 to form the wire When connected between two conductive pads, the dielectric layer 2 52 is formed on the center wire 210, which can effectively simplify the manufacturing process and increase the yield. In the wire connection formed according to the method shown in FIG. 8_13 of the present invention, the center wire 210 is covered by the dielectric layer 252, so the dielectric layer 252 can prevent adjacent wires 2 1 0 from contacting each other, so A short circuit situation will occur ', and the dielectric layer 2 5 2 can also reduce the phenomenon of electromagnetic interference. In addition, the conductive connection formed according to the method shown in Figs. 2-7 of the present invention is further provided with a conductive layer 2 54 covering the dielectric layer 252, thereby generating a shielding effect to reflect the light passing through the dielectric layer. Electromagnetic waves, so that undesired stray resistance, stray capacitance, and stray inductance will not be generated between the connection of different wires due to electromagnetic interference, and further effectively suppress the noise question. It is worth noting that the wires shown in Figure 7 The connection structure is similar to the structure of the same cable, so the wires 2 and 10 can be borrowed like a coaxial cable, and the thickness of the wire 2 is 2 to control the impedance of the wire 21. The impedance value is about 50 to 75 (ohms). Although the present invention has been Within the scope of the present invention, the above-mentioned preferred embodiment can be applied as an attachment to various aspects of the present invention to reveal those skilled in the art, without making changes and modifications. Because the scope of the patent is defined, it is not intended to limit the spirit of the present invention and the protection scope of the present invention.

1226692 Brief Description of Drawings [Simplified Illustration of Drawings] Figure 1 ·· Sectional view of the semiconductor package structure disclosed in the Republic of China Patent Application No. 0 9 1 1 33 2 7 2; Figures 2-7: It is used to describe a method for forming a wire interconnection according to an embodiment of the present invention; and FIGS. 8 to 13 are diagrams for explaining a method for forming a wire connection according to another embodiment of the present invention. Description of drawing number: 100 semiconductor package structure 110 substrate 120 chip 130 wire connection 140 encapsulant 132 wire 134 dielectric layer 136 metal layer 210 wire 21 2 sphere 214 ball joint 21 6 wire arc 218 wire exposed part 21 9 embossed joint 230 solder Nozzle 23 1 Solder tip 232 hole 234 hole 236 hole 239 wire clamp 240 wafer 242 wafer pad 252 dielectric layer 254 conductive layer 260 substrate 262 pad

00712.ptd Page 13

Claims (1)

1226692 6. Scope of patent application, 1. A method for forming a wire interconnection between a first and a second conductive pad, comprising: providing a capi 1 lary with an inner hole A middle hole surrounds the inner hole and an outer hole surrounds the middle hole; a sphere (ba 1 1) is formed at one end of the wire passing through the inner hole of the welding tip; and the ball of the wire is joined by using the welding tip Forming a ball bond on the first conductive pad, distributing a dielectric material from the middle hole of the tip to the surface of the ball bond to form a dielectric layer covering the ball bond; The conductive material is distributed from the outer hole of the welding tip to the surface of the dielectric layer covering the ball joint; the welding tip is moved and the dielectric material and the conductive material continue to flow from the fresh tip to the penetrating solder tip On the wire of the inner hole, a line arc is formed between the first and second conductive pads; after the line arc is formed, a stitch bond is formed on the second conductive pad to complete The line is connected. '2. The method of forming a wire connection between the first and second conductive pads according to item 1 of the scope of the patent application, wherein in the wire arc forming step, the dielectric material is continuously passed through the middle hole of the welding tip Flowing onto the wire and the conductive material continues to flow from the hole outside the tip to the dielectric material, whereby the formed arc has a dielectric layer covering the wire and a conductive layer covering the dielectric On the electrical layer. 00712.ptd Page 14 1226692 VI. Application scope 3, The method for forming a wire connection between the first and second conductive pads according to item 1 of the scope of patent application, wherein the step of forming the embossed joint includes: After the line arc is formed, continue moving the tip and stop the dielectric material and conductive material from flowing out of the tip, thereby forming an exposed portion of the wire at the end of the line arc that does not cover the dielectric material and the conductive material. ; Bonding the exposed part of the wire to the second conductive pad to form an embossed bond to the second conductive pad; and distributing the dielectric material from the middle hole of the welding tip to the surface of the embossed bond to A dielectric layer is formed to cover the embossed joint and the conductive material is distributed from the outer hole of the welding tip to the surface of the dielectric layer covered on the embossed joint. 4. The method for forming a wire connection between the first and second conductive pads according to item 1 of the scope of the patent application, wherein the first conductive pad is a wafer pad on a wafer, and the second conductive pad It is a pad on a substrate or a lead on a lead frame. 5. A method for forming a wire interconnection between a first and a second conductive pad, comprising: providing a solder cap (capi 1 1 ary) having an inner hole and an intermediate hole surrounding the inner side A hole and an outer hole surround the middle hole; a sphere (ba 1 1) is formed at one end of the wire passing through the inner hole of the welding tip; the ball of the wire is bonded to the first conductive pad by the welding tip In shape 00712.ptd Page 15 1226692 6. The scope of the patent application is a ball bond; a dielectric material is distributed from the middle hole of the tip to the surface of the ball joint to form a dielectric layer covering the ball joint ; Distribute a conductive material from the outer hole of the welding tip to the surface of the dielectric layer covering the ball joint; move the welding tip and continue the flow of the dielectric and conductive material from the welding tip to the penetration A wire arc is formed on the wire in the hole inside the welding tip between the first and second conductive pads; after the wire arc is formed, the welding tip is continued to move and the dielectric material and the conductive material are stopped. The solder nozzle flows out, thereby forming an exposed part of the wire that is not covered with the dielectric material and the conductive material at the end of the wire arc; joining the exposed part of the wire to the second conductive pad to form an embossed joint to the first Two conductive pads; and distributing the dielectric material from the middle hole of the tip to the surface of the embossed joint to form a dielectric layer covering the embossed joint and distribute the conductive material from the outer side hole of the tip To wrap over the imprint A dielectric layer formed on the surface together. 6. The method for forming a wire connection between the first and second conductive pads according to item 5 of the scope of the patent application, wherein in the wire arc forming step, the dielectric material is continuously passed through the middle hole of the fresh * mouth Flowing onto the wire and the conductive material continues to flow from the hole outside the tip to the dielectric material, whereby the formed arc has a dielectric layer covering the wire and a conductive layer covering the dielectric On the electrical layer. 00712.ptd Page 16 1226692 6. Application for patent scope 7. Method for forming a wire connection between the first and second conductive pads according to item 5 of the patent application scope, wherein the first conductive pad is a chip And the second conductive pad is a pad on a substrate or a lead on a lead frame. 00712.ptd Page 17