TWI220462B - None-sticking detection method - Google Patents

Abstract

A none-sticking detection method is conducted in a substrate strip with a plurality of semiconductor chips provided thereon. The substrate strip includes a plurality of substrate units, a plurality of plating bars between the substrate units and a plurality of plating pads connecting to the plating bars. Each substrate unit has a plurality of leads directly connecting to one of the plating bars adjacent to the leads. The method includes: (a) forming a first bonding wire electrically connected between one of the semiconductor chips and one of the leads; (b) connecting a first end of a second bonding wire to the semiconductor chip to which the first bonding wire is electrically connected using a capillary of a wire bonder electrically connected to a detector having a probe; (c) contacting the probe to one of the plating pads; (d) applying a predetermined amount of power to the capillary; and (e) checking whether a predetermined amount of electric current is detected by the detector after the connecting step of the first end of the second bonding wire and the probe contacting step.

Description

1220462 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a soldering non-stick detection method for manufacturing an array molding package structure (M AP (mold array p a c k a g e)). [Previous Technology] In the chip packaging process, wire bonding (w i r e b ο n d i n g) is the most commonly used technology for chip connection. Generally, a semiconductor wafer and a substrate are connected to each other by thermal compression bonding or ultrasonic welding. In the conventional packaging process, a semiconductor wafer is generally attached to a substrate via an adhesive layer (e ρ ο X y). Then, the aforementioned wire bonding technology is used to connect the zinc wires (b ο n d i n g w i r e) to the wafer pads on the surface of the wafer and the fingers of the conductive lines on the substrate. Finally, the wafer, bonding wires, and a portion of the substrate (including most of the conductive lines) are covered with a gel. In the above-mentioned packaging process, it is generally necessary to test whether the electrical connection between the bonding wire and the chip pad is good after wire bonding, that is, to detect non-stick soldering. The conventional welding non-stick detection is performed by manual visual inspection. However, visual inspection cannot achieve the required accuracy. In addition, during the wire bonding process, it is not possible to know whether there is no solder stickiness by visual inspection. Therefore, the visual inspection is performed at the same time as the reliability test (r e 1 i a b i 1 i t y t e s t) after the package structure is completed. If problems arise in the wire bonding process, all subsequent process steps will be a waste of time and material. Therefore, U.S. Patent Nos. 5 7 1 2 5 7 0 and 5 8 9 3 5 0 8 disclose a method for detecting non-stick welding during the wire bonding process, which involves applying power to the wire bonding machine during the wire bonding process. On the welding tip (capi 1 1 ary), and the detection is

00711.ptd Page 6 1220462 V. Description of the invention (2) Whether there is a loop (1 00 P) current to judge whether there is welding non-stick phenomenon. However, the methods disclosed in U.S. Pat. Nos. 5 7 1 2 5 7 0 and 5 8 9 3 5 0 8 require special design of test lines on the substrate, thereby increasing the difficulty of the circuit layout (ci r c u i t 1 a y o u t) on the substrate. In addition, the substrate sheet (substrate s t r i p) used to form a MAP (mold array package) generally includes a plurality of substrate units (typically 36 substrate units or more) arranged in an array. If the above-mentioned conventional method is applied to fabricate an array molded package structure (M A P (m ο 1 d a r r a y p a c k a g e)), a test circuit must be designed for each substrate unit, which will greatly increase the difficulty of increasing the circuit layout on the substrate. SUMMARY OF THE INVENTION The main object of the present invention is to provide a soldering non-stick detection method for wire bonding process, which can overcome or at least improve the aforementioned prior technical problems. The welding non-stick detection method according to the present invention is implemented in conjunction with a substrate strip that has been provided with a plurality of semiconductor wafers. The substrate strip includes a plurality of substrate units, and a plurality of plating bars are provided in the substrate strip. Between the plurality of substrate units and the plurality of pads connected to the plating line, each substrate unit has a plurality of wires (eads) directly connected to adjacent plating lines. The welding non-stick detection method according to the present invention comprises: (a) contacting the probe with one of the plurality of pads connected to a plating line; (b) forming a first bonding wire to be electrically connected to the One of the plurality of semiconductor wafers and one of the plurality of leads; (c) using a cap i 11 ary of a wire bonder to connect a first end of a second bonding wire to The already electrically connected

00711.ptd Page 7 1220462 V. Description of the invention (3) The probe connected to the probe of the first bonding wire and (e) After this step 5 check if the second welding is good, the probe should be connected with When the needle touches the wire, the electrically charged end, and the circui, if the current is good, the current is sliced. If it can be measured, the state is not because the plating line does not need to be carried out according to the nozzle. Then check the welding tip t). Because the second investigative representative should understand the representative of the good. According to the change of the measurement range, the power semiconductor for the detection of the second welding of the present invention is measured; (d) the second detection of the detection wire, the connection with the probe pad and the measurement of the welding wire. What the device can do is that the end of the second welding chip application wire is pin-connected to the end of the tester, and a welding detection wire is connected to the wire, rL, especially 5 and the connection detects a conductor crystal pad, 5 a pre-end Whether a semi-touched device with the second wire is electrically connected to an electrical step with a quantity of force to the welding tip; and a semiconductor between the first and the bonding wire between the probe contact piece. The chip is applied with a preset first terminal and a semiconductor to the current. The opposite end of the electrical terminal and the half detection line, if the line is the first detection, the fresh welding wire, the electroplating line, the second circuit (c 10 force between the fresh detection and the non-closed battery). Among the electric wafers, if the semi-conducting current is less than that of a pre-conductor wafer, the state of the connection is good, and the state of the sed tip of the wire is connected to any body-J-rL δ. The non-stick detection method utilizes the original test circuit of the substrate sheet. Therefore, the original circuit layout on the substrate according to the soldering non-stick detection method of the present invention can also be used for the welding state between the bonding wire and the semiconductor wafer. The welding non-stick detection method may further include using a second end of a wire of the wire bonding machine to be connected to one of the plurality of wires, and whether the current is not detected by the device. The applying step may be performed by applying a power source (for example, One DC or AC

0071i.ptd Page 8 1220462 V. Description of the invention (4) A current source, or a capacitor) is electrically connected between the recording nozzle and the probe. In order to make the above and other objects, features, and advantages of the present invention more obvious, the following describes the preferred embodiments of the present invention in detail with reference to the accompanying drawings. [Embodiment] FIG. 1 shows a substrate sheet (subs 7ra 1 estrip) 1 00 used in the present invention, which includes a plurality of substrate units 1 1 0 arranged in an array and a plurality of plating bars 120 Provided between the plurality of substrate units. The substrate sheet 100 is provided with a plurality of contacts 1 2 4 connected to the plating line 1 2 0. A plurality of wires (1 eads) 11 2 are provided on an upper surface of each substrate unit 1 10. As shown in FIG. 1, the first end portion 1 1 2 a of each of the wires 1 12 is used to be electrically connected to a semiconductor chip (not shown in the figure). The second end 1 1 2 b of each of the wires 1 1 2 is directly connected to the adjacent plated wire 1 2 0. A plurality of solder ball pads (not shown in the figure) are provided on the lower surface of each substrate unit 110, which are respectively electrically connected to corresponding leads 1 12 on the upper surface of the substrate unit. The manufacturing process of the substrate sheet 100 includes (A) laminating a conductive metal layer (such as copper foil with roughened surface) on a dielectric layer (for example, hot pressing). Suitable dielectric materials such as BT (bismaleimide-triazine) resin or FR-4 fiberglass reinforced epoxy resin (fiberglass reinforced epoxy resin) on both sides. (B) Formation of vias or through-holes in the product of (A), which can be formed by any conventional method, such as mechanical

00711.ptd Page 9 1220462 V. Description of the invention (5) Drilling or laser drilling. And, a conventional method such as electrodeless plating (e 1 e c t r ο 1 e s s p 1 a t 1 n g) is used to coat the via or via with a conductive metal such as copper. (C) Lithography (p h 0 t ο 1 i t h 0 g r a p h y) — A pattern is set in advance (for example, the pattern shown in FIG. 1) and the conductive metal layer is etched (e t c h i n g) to form a desired conductive line or conductive area. (D) Cover a surface of the product of (C) with a photoimageable solder resist (ph〇t ο 1 magab 1 es ο 1 dermask) (not shown), transfer the desired pattern, and develop to make the wire 1 1 2 The first end portion 1 1 2 a, the solder ball pad and the pad 12 4 are exposed to the solder resist; and (E) a material having a good bonding force with a conventional connecting wire (b ο ndingwire) material such as Gold or palladium is plated on a conductive metal layer that is not covered by the solder resist. It is worth noting that 'in step (E) 5 the electric ore line 120 is used as an electric transmission path for the electroplated gold or palladium layer. After a plurality of semiconductor wafers (only one semiconductor wafer 200 is shown in FIG. 2) are fixed on the substrate sheet 100 using an adhesive layer (such as epoxy resin), a wire-making process is performed including: forming a ball joint (Ba 1 1 b ο nd) on the semiconductor wafer 2 0 2 pads 2 0 2; forming a line arc between the pad 2 2 and the first end 1 1 2 a of the wire 1 1 2; finally forming a Stamp bonding (stitchb ο nd) to the first end portion 1 1 2 a of the wire 1 1 2 to complete the connection of the bonding wire. The welding non-stick detection method according to the present invention will be described in detail with the aforementioned wire bonding process. First, a first bonding wire 3 1 0 is electrically connected to the bonding pad 2 2 of the semiconductor wafer 2 0 and the first end portion 1 1 2 a of the lead 1 12. It can be understood that the first bonding wire 3 1 0 can be electrically connected to any ground on the semiconductor wafer 2 0 0

00711.ptd Page 10 1220462 V. Description of the invention (6) The method includes soldering directly on the surface of the wafer, as long as the first bonding wire 3 1 0 can form an electrical connection between the semiconductor wafer and the wire 1 1 2 . Next, a first end 3 2 0 a of a second bonding wire 3 2 利用 is connected to the first end 3 2 0 a of a second bonding wire 3 2 利用 by a capi 1 1 ary of a wireb ο nder. The bonding wire 3 1 0 is on a semiconductor wafer 2 0 0. In detail, the aforementioned process includes forming a sphere at the end of the welding wire drawn by the welding tip 400, and then heating and pressing the sphere on the welding pad 2 02, thereby the second welding wire 3 2 is formed. The ball formed at the first end of 0 is bonded to the pad 2 2 of the semiconductor wafer 2 0 0. The adhesion between the bonding wire sphere and the bonding pad 202 can be increased by applying an ultrasonic wave when the sphere is connected to the kettle. It is worth noting that the wire printer is electrically connected to a detector 4 2 0 having a probe 4 1 0. After contacting the probe 4 1 0 with the pad 1 2 4 (it can be understood that the probe 4 10 and the pad 1 2 4 can be joined together at the beginning of the wire bonding process), if the The soldering state between the first end of the second bonding wire 320 and the pad 2 2 of the semiconductor wafer is good. As shown in FIG. 3, the probe 4 10, the pad 1 24 in contact with the probe, and the first A bonding wire 3 10, a plating line 1 2 0 and a lead 1 1 connected between the pad in contact with the probe and the first bonding wire 2 The semiconductor wafer 2 0 electrically connected to the first bonding wire 0, the second bonding wire 3 2 0, the welding tip 4 0 0 and the detector 4 2 0 will form a closed circuit. Therefore, when a predetermined amount of power is applied to the welding tip (for example, a battery may be installed in the test machine, and when the first end of the second bonding wire 3 2 0 and the bonding pad 2 of the semiconductor wafer are 0 When the two contacts are in contact, the battery will supply current.) If the welding state between the first end of the second bonding wire 3 2 0 and the pad 2 of the semiconductor wafer is good, the detector

00711.ptd Page 11 1220462 V. Description of the invention (7) 4 2 0 can detect a current. Conversely, if no current is detected, it means that the first end of the second bonding wire 3 2 0 is not soldered to the semiconductor wafer. In addition, according to the welding non-stick detection method of the present invention, a current meter can also be used to measure the current intensity in the test circuit. If the detected current is less than a preset amount, it represents the second welding wire 3 2 The soldering state between the first end of 0 and the semiconductor wafer is not good. The aforementioned power application step can also be achieved by electrically connecting an alternating current 4 or a capacitor between the welding tip and the probe. It can be understood that the power supply can be integrated in the detector 4 200 or the wire-bonding machine, or externally connected between the welding tip 4 0 0 and the probe 4 1 0. Referring to FIG. 4, after connecting the first end 3 2 0 a of the second bonding wire 3 2 0 to the wafer 2 0, the bonding wire 3 2 0 is guided to the wire 1 by the welding tip 4 0 0. The first end portion 1 1 2 a of 1 2 is then embossed and bonded to the first end portion 1 1 2 a of the second bonding wire 3 2 0 3 2 0. After the embossing is completed, the remaining welding wire will be cut off, thereby completing the bonding operation of the welding wire 320. Because the welding wire is cut off, an open circuit (0 pen C ircuit) will be formed. Therefore, even if a predetermined amount of power is applied to the welding tip, if the welding wire is cut off, the detector 4 2 0 should not be able to detect Any current. If the current can still be detected, it means that the welding is not sticking. Since the welding non-stick detection method according to the present invention uses the original plating line 120 of the substrate sheet as a test circuit. Therefore, the welding non-stick detection method according to the present invention has the advantage that the original circuit layout on the substrate does not need to be greatly changed, and the welding state between the bonding wire and the semiconductor wafer can be measured during the wire bonding process. Although the present invention has been disclosed in the foregoing preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art will not depart from the spirit and scope of the present invention.

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00711.ptd Page 13 1220462 Brief description of the drawings [Simplified description of the drawings] Figure 1: Top view of the substrate sheet used in the present invention; Figure 2: It is used to explain the welding according to an embodiment of the present invention Sticky detection method; Figure 3: a circuit block diagram showing a detection circuit of the soldering non-sticky detection method of the present invention; and Figure 4: it is used to illustrate soldering non-stickyness according to another embodiment of the present invention Detection method. Description of drawing number: 100 substrate piece 1 10 substrate ασ early 120 plating line 124 pad 112 wire 1 12a first end 112b first-end 200 semiconductor wafer 202 pad 310 first wire 320 second wire 3 2 0 a First end 3 2 0 b First end 400 Welding tip 420 Detector

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Claims (1)

1220462 6. Scope of patent application 1. A soldering non-stick detection method for wire bonding process, which includes: providing a substrate sheet having a plurality of semiconductor wafers already provided; the substrate sheet includes a plurality of substrate units, a plurality of electrical devices; A money bar (P 1 atingbar) is provided between the plurality of substrate units and a plurality of pads connected to the plating line, wherein each substrate unit has a plurality of leads connected directly to adjacent plating lines; A probe is in contact with one of the pads connected to the plating line; a first bonding wire is electrically connected to one of the plurality of semiconductor wafers and one of the plurality of wires (1 eads); using a wire A capi 1 1 ary of a wire bonder connects a first end of a second bonding wire to the semiconductor chip that is electrically connected to the first bonding wire. The wire bonding machine is electrically connected to a A detector with a probe; applying a predetermined amount of power to the welding tip; and after the step of connecting the first end of the second wire and the step of contacting the probe, check whether the debt detector detects To current. 2. The non-stick welding detection method for the wire bonding process according to item 1 of the scope of the patent application, which further includes connecting a second end of the second wire to one of the plurality of wires by using a welding tip of the wire bonding machine. , And then check if the detector can no longer detect the current. 3. The welding non-stick detection method for wire bonding process according to item 1 of the scope of patent application, wherein the power application step is achieved by electrically connecting a power source between the welding tip and the probe. 00711.ptd Page 15 1220462 6. The scope of the patent application method: The process of measuring the warfare and recording the electricity and recording the electricity, the time-making line entered the step checker for the first step. Φ— According to the investigation, the probe has probed the main, and, the wire is in the lead and connected, the wire is welded to the first one, the wire is welded to the touch, and the probe is touched. The whole and connecting pins touch the probe to guide it. The wire welding test should be connected to the mouth of the mouth and welded by the mouth. The end of the wire is welded to the second line "" ^ 5th. Fan Li specially requested to measure the strength of the current detection by welding according to the law. If the line of the survey detection system is hit, Yu Du uses a strong term current electric power = α to measure the table including the other half of the body lead and the end of the line. Dai Liang does not, the state and quantity are fixed, and the welding is set in advance. 00711.pid Page 16