WO2023149605A1

WO2023149605A1 - Wire bonding method and device

Info

Publication number: WO2023149605A1
Application number: PCT/KR2022/009383
Authority: WO
Inventors: 김승규; 고한길; 손창준; 이강석
Original assignee: 에스케이하이닉스 주식회사; 가부시키가이샤 신가와
Priority date: 2022-02-07
Filing date: 2022-06-30
Publication date: 2023-08-10
Also published as: KR20230120187A; TW202333250A

Abstract

A wire bonding method and a wire bonding device are presented. The wire bonding method bonds a wire to form a bonding wire by using a bonding capillary which leads a wire, detects a defect occurring in a first tail of the wire, bonds the first tail of the wire to a discard lead, separates the first tail of the wire bonded to the discard lead from the wire, and guides a second tail to the separated wire. Wire bonding is performed again by using the wire to which the second tail is guided. A wire bonding device is configured to perform the wire bonding method.

Description

Wire bonding method and device

The present disclosure relates to semiconductor packaging technology, and more particularly, to a wire bonding method and a wire bonding apparatus.

A semiconductor package may include a semiconductor chip and a packaging substrate. A semiconductor chip may be mounted on a package substrate. Bonding wires may electrically connect the semiconductor chip and the package substrate. Bonding wires may be wire-bonded to the chip pads and leads to connect chip pads of the semiconductor chip and leads of the package substrate to each other. The plurality of chip pads may be electrical terminals formed on a semiconductor chip. The plurality of leads may be electrical terminals formed on the package substrate.

Process abnormalities may occur during a process of wire bonding bonding wires connecting a plurality of chip pads to a plurality of leads. If a process abnormality or process defect occurs during the wire bonding process to perform the wire bonding process, the equipment per wire bond may be momentarily stopped (momentary stop or momentary interruption) while generating a warning signal (alarm). When the wire bonding device is momentarily stopped, an operator may inspect the wire bonding device and take measures to restore a factor causing a process abnormality to a normal state.

The present disclosure is intended to provide a wire bonding method that self-recovers when a defect occurs in a wire bonding process. A wire bonding device used in the wire bonding method is presented.

One aspect of the present disclosure in order to achieve the above object is a first wire bonding step of forming a bonding wire using a bonding capillary leading the wire; detecting a defect caused in a first tail of the wire led by the bonding capillary; bonding the first tail of the wire to a discard lead; and separating a first tail of the wire bonded to the discard lead from the wire, and inducing a second tail to the separated wire.

Another aspect of the present disclosure includes a wire bonding step of connecting a bonding wire to a contact pad using a bonding capillary leading the wire; taking a visual image of the contact pad; determining whether the bonding wire is bonded to the contact pad or not, depending on a difference in brightness of the picture image as a part of the bonding wire overlaps the contact pad; bonding a first tail of the wire led by the bonding capillary to a discard lead; separating a first tail of the wire bonded to the discard lead from the wire, and inducing a second tail to the separated wire; transforming the second tail of the wire into a second free air ball; and bonding the second free air ball of the wire to the contact pad to which the bonding wire is not bonded.

Another aspect of the present disclosure is to form a bonding wire connecting a contact pad and a lead pad, a bonding capillary leading the wire; a first photographing unit detecting a defect caused to the tail of the wire led by the bonding capillary; a discard lead to which the first tail of the wire having the defect is bonded; and a control unit for controlling an operation in which the first tail of the wire that causes the defect is bonded to the discard lead and discarded.

According to embodiments of the present disclosure, a wire bonding method for self-recovering when a defect occurs in a wire bonding process may be presented. In addition, the present disclosure may suggest a wire bonding device used in the wire bonding method.

1 is a schematic diagram showing a wire bonding device according to an embodiment.

2 is a schematic process flow diagram showing a wire bonding method according to an embodiment.

3 to 10 are schematic diagrams showing detailed process steps of the wire bonding method of FIG. 2 .

11 is a schematic process flow chart showing a wire bonding method according to another embodiment.

12 to 22 are schematic diagrams showing detailed process steps of the wire bonding method of FIG. 11 .

23 and 24 are image images showing images of pads taken in the wire bonding method of FIG. 11 .

Terms used in the description of the present disclosure are terms selected in consideration of functions in the presented embodiments, and the meanings of the terms may vary depending on the intention or custom of users or operators in the technical field. The meanings of the terms used follow the definitions defined when specifically defined in this specification, and in the absence of specific definitions, they may be interpreted as meanings generally recognized by those skilled in the art.

In the description of the present disclosure, descriptions such as “first” and “second”, “side”, “top” and “bottom or lower” are for distinguishing members, and members themselves It is not used to limit or imply a specific order.

A semiconductor device may include a semiconductor substrate or a structure in which a plurality of semiconductor substrates are stacked. A semiconductor device may indicate a semiconductor package structure in which a structure in which semiconductor substrates are stacked is packaged. Semiconductor substrates may refer to a semiconductor wafer, semiconductor die or semiconductor chip on which electronic components and elements are integrated. A semiconductor chip is a memory chip in which a memory integrated circuit such as DRAM, SRAM, NAND FLASH, NOR FLASH, MRAM, ReRAM, FeRAM, or PcRAM is integrated, or a logic die or device in which a logic circuit is integrated in a semiconductor substrate. ASIC chips, application processors (APs), graphic processing units (GPUs), central processing units (CPUs), or system on chips (SoCs) can point to the same processor. Semiconductor devices may be applied to information communication devices such as portable terminals, electronic devices related to bio or health care, and wearable electronic devices. Semiconductor devices can be applied to the Internet of Things.

Like reference numbers throughout the specification may refer to like elements. The same reference numerals or similar reference numerals may be described with reference to other drawings, even if not mentioned or described in the drawings. Also, even if reference numerals are not indicated, description may be made with reference to other drawings.

1 is a schematic diagram showing a wire bonding device 10 according to an embodiment.

Referring to FIG. 1 , a wire bonding device 10 may include a bonding capillary 60, a clamp 50, and a controller 20. The bonding capillary 60 may direct a bonding tool that performs a wire bonding operation by leading the wire 40 , which is a material to be wire bonded. The wire 40 may include a gold wire. The clamp 50 may catch the wire 40 and supply it to the bonding capillary 60 . The wire 40 may be fed while penetrating the bonding capillary 60 . The tail 45 of the wire 40 comes out under the bonding capillary 60, and the tail 45 of the wire 40 forms a part to be deformed into a free air ball (FAB) shape. can instruct A torch 70, such as an electronic flame off wand, may be introduced around the tail 45 of the wire 40. The tail 45 of the wire 40 can be heated by a spark provided by the torch 70 and deformed into a free air ball shape.

A bonding wire 400 connecting a contact pad 210 and a lead pad 110 may be formed by a wire bonding operation by the bonding capillary 60 . The contact pad 210 may be disposed on the semiconductor chip 200 . The lead pad 110 may be disposed on the package substrate 100 . The package substrate 100 may be an electrical element on which the semiconductor chip 200 is mounted. The package substrate 100 may indicate an interconnection structure such as a printed circuit board (PCB) or an interposer. 1 illustrates that the bonding wire 400 electrically connects the semiconductor chip 200 and the package substrate 100, the bonding wire 400 has a structure that electrically connects the semiconductor chip 200 and other elements. can also be applied.

The contact pad 210 may be a terminal of the semiconductor chip 200 to which the first bonded portion 410 of the bonding wire 400 is bonded. The lead pad 110 may be another terminal of the package substrate 100 to which the second bonded portion 430 of the bonding wire 400 is bonded. The bonding wire 400 may include an extension part 420 extending to connect the first bonding part 410 to the second bonding part 430 .

The controller 20 of the wire bonding device 10 may include a wire bonding operation controller 21 that controls the wire bonding operation. The wire operation control unit 21 may substantially control the wire bonding operation by controlling operations of the bonding capillary 60 , the clamp 50 , and the torch 70 .

The control unit 20 of the wire bonding apparatus 10 may further include a failure detection control unit 22 that controls an operation of detecting abnormalities or failures that may occur during the wire bonding process. During the wire bonding process, abnormalities or defects may occur in the shape of the tail 45 of the wire 40 . Abnormalities or defects may be caused in the shape of the free air ball. The wire bonding device 10 may further include a first photographing unit 31 . The first photographing unit 31 may include an element capable of obtaining an image, such as a camera. The defect detection controller 22 controls the first capturing unit 31 to capture an image of the tail 45 of the wire 40, analyzes the captured image, and analyzes the captured image of the tail of the wire 40. (45) can be checked whether it is normal or defective.

The defect detection controller 22 may check whether the bonding wire 400 is bonded to the contact pad 210 or the lead pad 110 or not. The wire bonding device 10 may further include a second capturing unit 32 that captures images of the contact pads 210 and the lead pads 110 . The second capturing unit 32 may operate to capture an image of the contact pad 210 and move to capture an image of the lead pad 100 . The defect detection controller 22 analyzes the image images obtained by the second photographing unit 32 to determine whether the bonding wire 400 is bonded to the contact pad 210 or the lead pad 110 or not. You can check whether it exists or not.

When a defect caused to the tail 45 of the wire 40 is detected by the first photographing unit 31, the tail 45 of the wire 40 having the defect is removed, and the tail of the wire 40 is normal. A recovery operation including newly deriving a may be automatically performed. The control unit 20 of the wire bonding apparatus 10 further includes a recovery operation control unit 23, and the recovery operation control unit 23 may control such a self-recovery operation.

The wire bonding device 10 may include a discard lead 310 in which the tail 45 of the wire 40 causing the defect is discarded. The discard lead 310 may be disposed on a portion 300 of the package substrate 100 . The discard lead 310 may be disposed on the partial portion 300 of the package substrate 100 while being spaced apart from the contact pad 210 and the lead pad 110 . In another example, the portion 300 where the discard lead 310 is disposed may be introduced as a discard substrate separated from the package substrate 100 . The discard substrate may be an element spaced apart from the package substrate 100 or a separate substrate spaced apart from the package substrate 100 . In this way, the discard lead 310 may be disposed on a portion 300 of the package substrate 100 while being spaced apart from the lead pad 110, or may be disposed on a separate discard substrate spaced apart from the package substrate 100. . Accordingly, the discard lead 310 may be spaced apart from the package substrate 100 .

The recovery operation control unit 23 may bond the tail 45 of the defective wire 40 to the discard lead 310 and control an operation of discarding the tail 45 . The recovery operation control unit 23 may move the bonding capillary 60 onto the discard lead 310 and bond the tail 45 of the defective wire 40 to the discard lead 310 . The tail 45 bonded to the discard lead 310 is separated from the wire 40 by an operation in which the capillary 60 rises while holding the wire 40, and is bonded to the discard lead 310. can be discarded as The wire 40 from which the defective tail 45 has been removed may be returned to the wire bonding process.

Referring to FIGS. 2 and 1 , a wire bonding method may be performed using a wire bonding device 10 . The wire bonding method may include performing a wire bonding process ( S11 ). While a wire bonding process is performed using the wire bonding device 10, unwanted process defects may occur. If a defect is detected during the wire bonding process, the wire bonding device 10 may momentarily stop immediately while generating a warning. The wire bonding method may include detecting a defect in the first tail of the wire 40 ( S12 ). The wire bonding method includes the steps of transforming the first tail of the wire 40 into a first free air ball and bonding the first free air ball to the discard lead 310 (S13); 40) and inducing a second tail of the wire 40 (S14), transforming the second tail of the wire 40 into a second free air ball (S15), and It may include checking the state (S16) and returning to the wire bonding process (S17).

FIG. 3 is a schematic diagram showing a step S12 of detecting a defect in the first tail 45-1 of the wire 40 of the wire bonding method of FIG. 2. Referring to FIG.

Referring to FIG. 3 , a wire bonding process may be performed on the semiconductor chip 200 ( S11 of FIG. 2 ). The semiconductor chip 200 may be mounted on the package substrate 100 and a first wire bonding process may be performed using a wire bonding device ( 10 in FIG. 1 ). A first wire bonding process of forming the bonding wire 400 so that the bonding wire 400 connects the contact pad 210 and the lead pad 110 by using the bonding capillary 60 leading the wire 40. can be performed.

If a process defect occurs in the first wire bonding process, a defect may occur in the first tail 45 - 1 of the wire 40 . A defect caused in the first tail 45 - 1 of the wire 40 may be detected through the first photographing unit 31 . The first capture unit 31 captures an image of the first tail 45-1 of the wire 40, and the defect detection controller (22 in FIG. 1) of the controller (20 in FIG. 1) captures the captured image. It is possible to check defects generated in the first tail 45-1 of the wire 40 from the image. The defect detection controller 22 may include an algorithm for checking the shape of the wire, such as a reference position system (RPS). If a process defect occurs in the first wire bonding process, the first tail 45 - 1 of the wire 40 may be deformed. A defect in which the first tail 45-1 of the wire 40 is bent or different from the normal length may occur in the first tail 45-1 of the wire 40. Defects occurring in the first tail 45-1 of the wire 40 can be confirmed by a photographed image.

4 and 5 are schematic diagrams showing a step (S13) of bonding the first tail 45-3 of the wire 40 to the discard lead 310 of the wire bonding method of FIG. 4 is a schematic view showing a step of forming a first tail 45-2 having a first free air ball shape of the wire 40 in a wire bonding method. FIG. 5 is a schematic diagram showing a step of bonding the first tail 45 - 3 of the wire 40 to the discard lead 310 of the wire bonding method.

Referring to FIG. 4 , when defects occurring in the first tail 45-1 of the wire 40 are confirmed, the first tail 45-1 of the wire 40 is replaced with a first tail 45 having a first free air ball shape. -2) can be transformed. By applying a spark 71 to the first tail 45-1 of the wire 40 using the torch 70, the first tail 45-1 of the wire 40 is shaped like a first free air ball. It can be transformed into the first tail 45-2.

5, by operating the bonding capillary 60, the first tail (45-2 in FIG. 4) of the first free air ball shape of the wire 40 can be bonded to the discard lead 310. there is. The bonding capillary 60 is lowered toward the discard lead 310 so that the first tail 45 - 2 of the first free air ball shape of the wire 40 is coupled to the discard lead 310 . Accordingly, the first tail 45 - 3 of the wire 40 bonded to the discard lead 310 may be formed. In this way, the first tail (45-1 in FIG. 3) of the wire 40 is deformed into a first tail (FIG. 45-2) having a first free air ball shape, and the first tail (45-1 in FIG. 3) of the wire 40 3) to the discard lead 310, the first tail (45-1 in FIG. 3) of the defective wire 40 may be substantially bonded to the discard lead 310.

FIG. 6 is a schematic diagram showing a step (S14) of inducing the second tail 45-4 of the wire 40 in the wire bonding method of FIG. 2. Referring to FIG.

Referring to FIG. 6 , after bonding the first tail 45-3 of the wire 4 to the discard lead 310, the first tail 45-3 of the wire 40 may be separated from the wire 40. can The wire 40 may be separated from the first tail 45 - 3 of the wire 40 by ascending the bonding capillary 60 . Since the bonding capillary 60 rises while holding the wire 40, the wire 40 rises while being guided by the bonding capillary 60 from the first tail 45-3 of the wire 40. can be separated As the first tail 45-3 of the wire 40 is separated from the main body of the wire 40 in this way, the distal end portion of the separated wire 40 acts as or is set as a new second tail 45-4. can A process of bonding the first tail 45 - 3 of the wire 40 to the discard lead 310 and separating it from the wire 40 may be substantially the same as the normal wire bonding process. Accordingly, the second tail 45 - 4 of the newly set wire 40 may have a normal shape recovered or recovered from a defect.

7 and 8 are schematic diagrams showing a step (S15) of transforming the second tail 45-4 of the wire 40 of the wire bonding method of FIG. 2 into a second free air ball. 7 is a schematic view showing a step of checking the state of the second tail 45-4 of the wire 40 in the wire bonding method. FIG. 8 is a schematic diagram showing a step of forming a second tail 45 - 5 in the shape of a second free air ball of the wire 40 of the wire bonding method.

Referring to FIG. 7, a video image of the second tail 45-4 of the wire 40 is photographed using the first photographing unit 31, and the second tail 45 of the wire 40 is obtained from the video image. You can check the status of -4). The recovery operation controller 23 of the controller 20 of the wire bonding device 10 controls the first photographing unit 31 to secure an image of the second tail 45-4 of the wire 40, , It is possible to check whether the state of the second tail 45-4 of the wire 40 is normal or defective by analyzing the secured image.

When the state of the second tail 45 - 4 of the wire 40 is confirmed to be in a defective state, process steps for discarding the second tail 45 - 4 of the wire 40 may be performed. Process steps for discarding the second tail 45-4 of the wire 40 may be performed substantially the same as process steps for discarding the first tail 45-3 as described with reference to FIGS. 4 to 6. can When the state of the second tail 45-4 of the wire 40 is confirmed to be normal, as shown in FIG. 8, a spark 73 is applied to the second tail 45-4 of the wire 40 to , the second tail 45-4 of the wire 40 can be transformed into a second tail 45-5 having a second free air ball shape.

FIG. 9 is a schematic view showing a step of checking the state of the second free air ball shape of the second tail 45 - 5 of the wire 40 of FIG. 2 .

Referring to FIG. 9 , an image of the second tail 45 - 5 deformed into a second free air ball shape of the wire 40 may be captured using the first capturing unit 31 . The state of the second tail 45-5 of the wire 40 can be confirmed from the photographed image. The recovery operation controller (23 in FIG. 1) of the controller (20 in FIG. 1) of the wire bonding device (10 in FIG. 1) controls the first photographing unit 31, so that the second tail 45- of the wire 40 An image of the shape of the second free air ball in 5) is secured, and the obtained image is analyzed to determine whether the shape of the second free air ball of the second tail 45-5 of the wire 40 is normal or defective. You can check whether it exists. When the state of the second tail 45 - 5 of the wire 40 is confirmed to be in a defective state, process steps for discarding the second tail 45 - 5 of the wire 40 may be performed. When the state of the second tail 45 - 5 of the wire 40 is confirmed to be normal, the wire bonding process may be returned.

FIG. 10 is a schematic diagram showing a step S17 of returning to the wire bonding process of FIG. 2 .

Referring to FIG. 10 , a second wire bonding process step may be performed using the wire 40 in which the second tail 45 - 5 of the wire 40 is deformed into a second free air ball shape. The bonding capillary 60 operates so that the second free air ball shape of the second tail 45-5 contacts the contact pad 210N and the contact pad 210N and the second free air ball are coupled. can The contact pad 210N and the lead pad 110N shown in FIG. 10 are sequentially connected to the contact pad (210 in FIG. 9) and the lead pad (110 in FIG. 9) connected by a bonding wire (400 in FIG. 9). can be placed.

As shown in FIG. 3, a defect caused by the first tail 45-1 of the wire 40 is detected, and as shown in FIG. 4, the first tail 45-2 of the wire 40 is first free. It is deformed into an air ball shape, and as shown in FIG. 5 , the first tail 45 - 3 of the wire 40 may be bonded to the discard lead 310 . As shown in FIG. 6, the process steps of newly inducing the second tail 45-4 of the wire 40 may constitute a process step of restoring or recovering the defective wire 40 to a normal state. . In the recovery process step, as shown in FIGS. 7 and 8, the second tail 45-4 of the wire 40 is transformed into a second free air ball, and as shown in FIG. 9, the second tail of the wire 40 After confirming the state of the second free air ball shape of (45-5), as shown in FIG. 10, second wire bonding process steps may be further included.

In this recovery process step, the recovery operation control unit 23 of the control unit 20 of the wire bonding device 10 of FIG. By controlling the operation of 70, the wire bonding device 10 itself can be performed. Accordingly, an operator's intervention to treat the defective wire 40 may be omitted, and productivity of the wire bonding process may be improved.

Referring to FIG. 11 , a wire bonding method may be performed using the wire bonding device 10 of FIG. 1 . The wire bonding method may include performing a wire bonding process ( S21 ). The wire bonding method may include detecting a defect in the first tail of the wire ( S22 ). The wire bonding method may include checking states of a contact pad and a lead pad where wire bonding has been attempted ( S23 ). The wire bonding method includes: transforming a first tail of a wire into a first free air ball and bonding the first free air ball to a discard lead (S24); separating the first free air ball from the wire to form a second free air ball of the wire; Inducing a tail (S25), transforming the second tail of the wire into a second free air ball (S26), checking the state of the second free air ball (S27), and returning to the wire bonding process It may include a step (S28) of doing.

12 to 15 are schematic diagrams showing the step S23 of checking the states of the contact pad 2210 and the lead pad 2110 of FIG. 11 . FIG. 12 is a schematic diagram showing bonding wires 2400 bonded to contact pads 2210 and lead pads 2110 . FIG. 13 is a schematic diagram showing image images of the contact pad 2210 and the lead pad 2110 of FIG. 12 . FIG. 14 is a schematic diagram showing that the contact pad 2210 and the lead pad 2110 are not bonded with bonding wires. FIG. 15 is a schematic diagram showing image images of the contact pad 2210 and the lead pad 2110 of FIG. 14 . In FIGS. 13 and 15, elements depicted in the same shape as those in FIG. 3 or elements indicated by the same reference numerals may indicate substantially the same elements.

Referring to FIG. 12 together with FIG. 11 , a wire bonding process may be performed on the semiconductor chip 2200 ( S21 ). The semiconductor chip 2200 may be mounted on the package substrate 2100 and a wire bonding process may be performed using a wire bonding device ( 10 in FIG. 1 ). The bonding wire 400 may be formed so that the bonding wire 2400 connects the contact pad 2210 and the lead pad 2110 by using the bonding capillary 60 leading the wire 40 . The bonding wire 2400 may include a first bonding portion 2410 , a second bonding portion 2430 , and an extension portion 2420 . The discard lead 2310 may be disposed on a partial portion 2300 of the package substrate 2100 . A first partial portion 2420A of the extension portion 2420 of the bonding wire 2400 may overlap the contact pad 2210 . The first partial portion 2420A of the extension 2420 of the bonding wire 2400 may be located at a position elevated from the contact pad 2210 by a predetermined height difference (H). Another second partial portion 2420B of the extension portion 2420 of the bonding wire 2400 may overlap the lead pad 2110 .

If a process defect occurs in the first wire bonding process, a defect may occur in the first tail 2045 - 1 of the wire 40 . A defect caused in the first tail 2045-1 of the wire 40 may be detected through the first photographing unit 31 (S22).

When a process defect occurs in the first wire bonding process or when a defect is detected in the first tail 2045-1 of the wire 40, the states of the contact pad 2210 and the lead pad 2110 can be checked. Yes (S23). It may be checked whether the bonding wire 2400 is bonded to the contact pad 2210 and the lead pad 2110 or not.

Referring to FIGS. 12 and 13 , the second capturing unit 32 may be introduced onto the contact pad 2210 and capture an image of the contact pad 2210 . The second capturing unit 32 is introduced onto the lead pad 2110 and can capture an image of the lead pad 2110 . 13 may schematically show image images 2210C-1 and 2110C-1 of the contact pad 2210 and the lead pad 2110 obtained by the second capturing unit 32.

As shown in FIG. 12 , when the bonding wire 2400 is bonded to the contact pad 2210, the image 2210C of the contact pad 2210 of FIG. 13 is the surface of the contact pad 2210. , and the first partial portion 2420A of the extension 2420 of the bonding wire 2400 may be included as a shade. As shown in FIG. 12 , the first partial portion 2420A of the extension 2420 of the bonding wire 2400 is positioned higher than the surface of the contact pad 2210 by a height difference H. The first partial portion 2420A of the extension 2420 of the bonding wire 2400 may cast a shadow on the surface of the contact pad 2210 .

As shown in FIG. 12, if the bonding wire 2400 is bonded to the lead pad 2110, the image 2110C captured for the lead pad 2110 in FIG. 13 is the surface of the lead pad 2110. , and the second partial portion 2420B of the extension 2420 of the bonding wire 2400 may be included as a shade. The second partial portion 2420B of the extension portion 2420 of the bonding wire 2400 is also positioned higher than the surface of the lead pad 2110 . The second partial portion 2420B of the extension 2420 of the bonding wire 2400 may also cast a shadow on the surface of the contact pad 2210 .

As shown in FIG. 14 , when the bonding wire is not bonded to the contact pad 2210, the image 2210C-1 captured for the contact pad 2210 of FIG. 15 is the surface of the contact pad 2210. may contain only images of The picture image 2210C-1 does not include a shadow by the first partial portion (2420A in FIG. 12) of the extension portion (2420 in FIG. 12) of the bonding wire (2400 in FIG. 12). If the bonding wire is not bonded to the lead pad 2110, the image 2110C-1 taken of the lead pad 2110 in FIG. 15 includes only the image of the surface of the lead pad 2110, and bonding There is no shadow caused by the second partial portion (2420B in FIG. 12) of the extension portion 2420 of the wire 2400.

13 and 15, as the first partial portion 2420A of the bonding wire 2400 overlaps the contact pad 2210, the brightness of the visual image 2210C changes to the visual image 2210C-1. ) can be changed differently from the brightness of In the visual image 2210C, the first partial portion 2420A of the bonding wire 2400 may appear dark, so the brightness of the visual image 2210C may represent a lower value than that of the visual image 2210C-1. In addition, as the second partial portion 2420B of the bonding wire 2400 overlaps the lead pad 2110, the brightness of the visual image 2110C may change differently from the brightness of the visual image 2110C-1. In the visual image 2110C, the second partial portion 2420B of the bonding wire 2400 may appear dark, so the brightness of the visual image 2110C may represent a lower value than that of the visual image 2110C-1.

In this way, as some

parts

2420A and 2420B of the bonding wire 2400 overlap the contact pad 2210 or the lead pad 2110, the obtained

image images

2210C, 2210C-1 or 2110C, 2110C-1 ) can be changed. Depending on the brightness difference of these

image images

2210C, 2210C-1 or 2110C, 2110C-1, whether the bonding wire 2400 is bonded to the contact pad 2210 or the lead pad 2110 or not bonded is determined. You can check whether it exists or not.

Referring back to FIG. 13 , whether or not the bonding wire 2400 is bonded to the contact pad 2210 or not is determined by using the image 2210C of the contact pad 2210 as a reference line 211-R. ) is interposed between the first part 2210C-A and the second part 2210C-B of the video image 2210C, and the first part 2210C-A of the video image 2210C and the video image It can be confirmed by comparing the brightness difference of the second part 2210C-B of 2210C. The reference line 211 -R may be set as a line passing through a contact point of the first bonding portion 2410 of the bonding wire 2400 bonded to the contact pad 2210 .

The first portion 2210C-A of the visual image 2210C may include a portion where the first partial portion 2420A of the bonding wire 4200 does not overlap or is not expected to overlap the contact pad 2210. . The second portion 2210C-B of the visual image 2210C may include a portion where the first partial portion 2420A of the bonding wire 4200 overlaps the contact pad 2210 or is expected to overlap. The first part 2210C-A of the video image 2210C and the second part 2210C-B of the video image 2210C are shaded by the first part 2420A of the bonding wire 4200. , can show different values.

A difference in brightness between the first part 2210C-A of the visual image 2210C and the second part 2210C-B of the visual image 2210C is checked, and if there is a difference in brightness as shown in FIG. 13, the difference in brightness is determined. Based on the indication, it can be determined that the bonding wire 2400 is bonded to the contact pad 2210 . As shown in FIG. 15, if there is substantially no difference in brightness between the first portion 2210C-A of the visual image 2210C and the second portion 2210C-B of the visual image 2210C, the brightness of the visual image 2210C It is determined that the bonding wire 2400 is not bonded to the contact pad 2210 based on the fact that the first portion 2210C-A and the second portion 2210C-B of the visual image 2210C exhibit substantially the same brightness. can do.

Referring back to FIG. 13 , whether or not the bonding wire 2400 is bonded to the lead pad 2110 or not is determined by using an image 2110C of the lead pad 2110 as a reference line 211-R. ) is interposed between the first part 2110C-A and the second part 2110C-B of the video image 2110C, and the first part 2110C-A of the video image 2110C and the video image It can be confirmed by comparing the brightness difference of the second part 2110C-B of 2110C.

A difference in brightness between the first part 2110C-A of the visual image 2110C and the second part 2110C-B of the visual image 2110C is confirmed, and if there is a difference in brightness as shown in FIG. 13, the difference in brightness is determined. Based on the indication, it can be determined that the bonding wire 2400 is bonded to the lead pad 2110. As shown in FIG. 15, if there is substantially no difference in brightness between the first portion 2110C-A of the visual image 2110C and the second portion 2110C-B of the visual image 2110C, the brightness of the visual image 2110C It is determined that the bonding wire 2400 is not bonded to the lead pad 2110 based on the fact that the first portion 2110C-A and the second portion 2110C-B of the visual image 2110C exhibit substantially the same brightness. can do.

In this way, by checking whether the bonding wire 2400 is bonded or unbonded to the contact pad 2210 or the lead pad 2110, the contact pad 2210 and the lead pad to which the wire bonding process is to be restored. The position of (2110) can be sensed. If it is confirmed that the bonding wire 2400 is bonded to the contact pad 2210 and the lead pad 2110, the wire bonding process may proceed to form another bonding wire to the next contact pad or the next lead pad. If it is confirmed that the bonding wires are not bonded to the contact pads 2210 and the lead pads 2110, the wire bonding process may proceed to form the bonding wires again on the contact pads 2210 or the lead pads 2110.

23 and 24 are image images showing images of pads 2210P and 2210PB captured in the wire bonding method of FIG. 11 . 23 is an image taken of pads 2210P to which bonding wires are not attached or bonded, and FIG. 24 is an image taken of pads 2210PB to which bonding wires 2400B are attached or bonded. It is an image. Pads 2210P and 2210PB may indicate contact pads 2210 or lead pads 2110 .

Referring to FIG. 24 , when the bonding wire 2400B is attached to the pad 2210PB, the bonding wire 2400B does not project illumination light reflected from the bonding wire 2400B to the camera, and dark areas in the image, That is, it may appear as a part having relatively low brightness. The bonding wire 2400B may cover the pad 2210PB and appear in the image as a shaded shape. On the other hand, when the bonding wire is not attached to the pad 2210P, as shown in FIG. 23 , illumination light reflected from the pad 2210P is projected to the camera, and the brightness of the entire image can be relatively bright. . Since the bonding wire does not cover the pad 2210P, an image without a shaded portion can be captured. Comparing the visual images of FIGS. 23 and 24 , the brightness of the same area of the visual image may appear different depending on whether or not the bonding wire 2240B is bonded to the pads 2210PB and 2210P. By comparing the brightness of the picture images of FIGS. 23 and 24 with each other, it is possible to determine whether the bonding wire 2240B is bonded to the pads 2210PB and 2210P or not.

16 and 17 are schematic diagrams showing a step (S24) of bonding the first tail 2045-3 of the wire 40 to the discard lead 2310 in the wire bonding method of FIG. 16 is a schematic diagram showing a step of forming a first tail 2045-2 having a first free air ball shape of the wire 40 in a wire bonding method. 17 is a schematic diagram showing a step of bonding the first tail 2045 - 3 of the wire 40 to the discard lead 2310 of the wire bonding method. In FIGS. 16 and 17 , elements depicted in the same shape as those in FIGS. 4 and 5 or elements indicated by the same reference numerals may indicate substantially the same elements.

Referring to FIG. 16 , when defects occurring in the first tail 2045-1 of the wire 40 are confirmed, the first tail 2045-1 of the wire 40 is replaced with a first tail 2045 having a first free air ball shape. -2) can be transformed.

17, by operating the bonding capillary 60, the first tail (2045-2 in FIG. 16) of the first free air ball shape of the wire 40 can be bonded to the discard lead 2310. there is. Accordingly, the first tail 2045 - 3 of the wire 40 bonded to the discard lead 2310 may be formed.

FIG. 18 is a schematic diagram showing a step ( S25 ) of inducing the second tail 2045 - 4 of the wire 40 of the wire bonding method of FIG. 11 . In FIG. 18, elements depicted in the same shape as those in FIG. 6 or elements indicated by the same reference numerals may indicate substantially the same elements.

Referring to FIG. 18 , after bonding the first tail 2045-3 of the wire 40 to the discard lead 310, the first tail 2045-3 of the wire 40 is separated from the wire 40. can do. By separating the first tail 2045 - 3 of the wire 40 from the main body of the wire 40 , the second tail 2045 - 4 may be guided to the separated wire 40 .

19 and 20 are schematic diagrams showing a step (S26) of transforming the second tail 2045-4 of the wire 40 of the wire bonding method of FIG. 11 into a second free air ball. 19 is a schematic diagram showing a step of checking the state of the second tail 2045-4 of the wire 40 in the wire bonding method. FIG. 20 is a schematic view showing a step of forming a second tail 2045 - 5 having a second free air ball shape of the wire 40 of the wire bonding method. In FIGS. 19 and 20 , elements depicted in the same shape as those in FIGS. 7 and 8 or elements indicated by the same reference numerals may indicate substantially the same elements.

Referring to FIG. 19, a video image of the second tail 2045-4 of the wire 40 is photographed using the first photographing unit 31, and the second tail 2045 of the wire 40 is obtained from the video image. You can check the status of -4).

Referring to FIG. 20 , a spark 73 is applied to the second tail (2045-4 of FIG. 19 ) of the wire 40 so that the second tail 2045-4 of the wire 40 is a second free air ball. It can be transformed into a shaped second tail (2045-5).

FIG. 21 is a schematic view showing a step (S27) of checking the state of the second free air ball shape of the second tail 2045-5 of the wire 40 of FIG. 11. Referring to FIG. In FIG. 21, elements depicted in the same shape as those in FIG. 9 or elements indicated by the same reference numerals may indicate substantially the same elements.

Referring to FIG. 21 , an image of the second tail 2045 - 5 deformed into the second free air ball shape of the wire 40 may be captured using the first capturing unit 31 . The state of the second tail 2045 - 5 of the wire 40 can be confirmed from the photographed image.

FIG. 22 is a schematic diagram showing a step S28 of returning to the wire bonding process of FIG. 11 . In FIG. 21, elements depicted in the same shape as those in FIG. 9 or elements indicated by the same reference numerals may indicate substantially the same elements.

Referring to FIG. 22 , a wire bonding process step may be performed again using the wire 40 in which the second tail 2045 - 5 of the wire 40 is deformed into a second free air ball shape. The bonding capillary ( 60) may work. 12 to 15 , it is confirmed in advance that no bonding wire is formed on the contact pad 2210, and thus the second tail 2045-5 of the wire 40 is attached to the contact pad 2210. ) of the second free air ball shape can be bonded without defects. Since it can be confirmed in advance that no bonding wire is formed on the contact pad 2210, the second free air ball shape of the second tail 2045-5 of the wire 40 is bonded again to the pad to which the bonding wire is bonded. Bonding failure (double bonding failure) can be reduced or prevented in advance.

So far, the present disclosure has been looked at based on embodiments. Those skilled in the art to which the present disclosure pertains will be able to understand that the present disclosure may be implemented in a modified form within a range that does not deviate from its essential characteristics. Therefore, the disclosed embodiments should be considered from an illustrative rather than a limiting point of view. The scope of the present disclosure is shown in the claims rather than the foregoing description, and all differences within the equivalent range should be construed as being included in the present disclosure.

Claims

a first wire bonding step of forming a bonding wire using a bonding capillary leading the wire;

detecting a defect caused in a first tail of the wire led by the bonding capillary;

bonding the first tail of the wire to a discard lead; and

and separating a first tail of the wire bonded to the discard lead from the wire, and inducing a second tail to the separated wire.
According to claim 1,

Bonding the first tail of the wire to the discard lead

transforming the first tail of the wire into a first free air ball; and

and bonding the first free air ball to the discard lead.
According to claim 2,

The bonding wire is

connecting contact pads and lead pads;

The discard lead is a wire bonding method spaced apart from the lead pad.
According to claim 3,

the contact pad

placed on a semiconductor chip;

The lead pad

It is disposed on a package substrate on which the semiconductor chip is mounted,

The discard lead is

It is disposed on the package substrate while being spaced apart from the lead pad, or

Wire bonding method disposed on a separate discard substrate spaced apart from the package substrate.
According to claim 1,

The step of detecting a defect caused by the first tail of the wire

taking a visual image of the first tail of the wire; and

and confirming the defect of the first tail of the wire from the picture image.
According to claim 1,

transforming the second tail of the wire into a second free air ball; and

and a second wire bonding step in which the second tail is performed using the wire transformed into the second free air ball.
According to claim 6,

taking a picture image of the second free air ball deformed from the second tail of the wire; and

and checking whether or not the second free air ball is defective from the image.
According to claim 6,

Before the step of transforming the second tail of the wire into the second free air ball,

photographing a visual image of the second tail of the wire; and

and confirming whether the second tail of the wire is normal or defective from the picture image.
a wire bonding step of connecting the bonding wire to the contact pad using a bonding capillary leading the wire;

taking a visual image of the contact pad;

determining whether the bonding wire is bonded to the contact pad or not, depending on a difference in brightness of the picture image as a part of the bonding wire overlaps the contact pad;

bonding a first tail of the wire led by the bonding capillary to a discard lead;

separating a first tail of the wire bonded to the discard lead from the wire, and inducing a second tail to the separated wire;

transforming the second tail of the wire into a second free air ball; and

and bonding the second free air ball of the wire to the contact pad to which the bonding wire is not bonded.
According to claim 9,

Bonding the first tail of the wire to the discard lead

transforming the first tail of the wire into a first free air ball; and

and bonding the first free air ball to the discard lead.
According to claim 9,

taking a picture image of the second free air ball deformed from the second tail of the wire; and

and checking whether or not the second free air ball is defective from the picture image.
According to claim 9,

Prior to bonding the first tail of the wire to the discard lead,

The wire bonding method further comprising detecting a defect caused to the first tail of the wire.
According to claim 12,

The step of detecting a defect caused by the first tail of the wire,

taking a visual image of the first tail of the wire; and

and confirming the defect of the first tail of the wire from the picture image.
According to claim 9,

The wire bonding step

The bonding wire extends from the contact pad and is connected to a lead pad,

The discard lead is spaced apart from the contact pad and the lead pad.
According to claim 14,

the contact pad

placed on a semiconductor chip;

The lead pad

It is disposed on a package substrate on which the semiconductor chip is mounted,

The discard lead is

A wire bonding method disposed on the package substrate or disposed on a separate discard substrate spaced apart from the package substrate.
According to claim 15,

taking a picture image of the lead pad; and

Depending on the brightness difference of the video image as a part of the bonding wire overlaps the lead pad, determining whether the bonding wire is bonded or not bonded to the lead pad Further comprising wire bonding method.
According to claim 9,

The step of checking whether the bonding wire is bonded or not bonded to the contact pad,

dividing the video image into a first portion in which a portion of the bonding wire overlaps or is expected to overlap, and a second portion in which a portion of the bonding wire does not overlap or is expected not to overlap;

checking brightnesses of the first part and the second part of the video image;

determining that the bonding wire is bonded to the contact pad based on a difference in brightness between the first portion and the second portion of the visual image; and

and determining that the bonding wire is not bonded to the contact pad based on the fact that the first part and the second part of the picture image exhibit substantially the same brightness.
a bonding capillary leading the wire to form a bonding wire connecting the contact pad and the lead pad;

a first photographing unit detecting a defect caused to the tail of the wire led by the bonding capillary;

a discard lead to which the first tail of the wire having the defect is bonded; and

A wire bonding device including a control unit for controlling an operation in which the first tail of the wire having the defect is bonded to the discard lead and discarded.
According to claim 18,

The discard lead is

A wire bonding device disposed on a package substrate while being spaced apart from the contact pad and the lead pad.
According to claim 18,

and a second photographing unit for checking whether the bonding wire is bonded to the contact pad and the lead pad.