Gold wire for camera module

Abstract

The present invention provides a gold wire for a camera module, wherein the gold wire includes a first access end, a second access end, and a wiring end, wherein the wiring end connects the first access end and the second access end, the first access end extends obliquely downward from the wiring end, and the second access end extends vertically downward from the wiring end.

Description

Technical Field

[0001] The present invention relates to the technical field of camera module processing, and in particular to a camera module gold wire. Background Art

[0002] Since the first camera phone, built-in cameras have become a staple of electronic products like mobile phones and tablets. With the increasing demand for camera modules and their pixel counts, automated quality inspection has become increasingly important. With the widespread adoption of mobile electronic devices, the technology behind camera modules (used to capture images, such as videos or pictures) has rapidly developed and advanced. In recent years, technological advancements have accelerated, particularly in the field of electronics, which has progressed at an astonishing pace. Competition in the camera module market has become increasingly fierce, leading to significant advancements in both structure and performance.

[0003] Both in terms of functionality and size, devices are constantly evolving in ways that people imagine, achieving highly complex functions while becoming increasingly compact and miniaturized. In camera modules, the photosensitive chip is connected to the circuit board via gold wires (w / b wires). During assembly, these wires are set to a fixed shape. However, during use, the electronic device inevitably drops, causing the wires to wobble or deform, impacting image quality and shortening the module's lifespan. A dropped camera module can also create the risk of the wires becoming attached, resulting in a loss of image quality or even a wire melt. Summary of the Invention

[0004] A major advantage of the present invention is that it provides a gold wire for a camera module, wherein the gold wire has a gold wire shape that can reduce the amplitude of the gold wire when the camera module falls.

[0005] Another advantage of the present invention is that it provides a gold wire for a camera module, wherein the gold wire includes an inner arc gold wire, wherein the arc height LH of the inner arc gold wire is 75 μm, the horizontal segment length SL is 45 μm, and the total arc length is 400 microns.

[0006] Another advantage of the present invention is to provide a gold wire for a camera module, wherein the gold wire includes an outer arc gold wire, wherein the arc height LH of the outer arc gold wire is 132 μm, the horizontal segment length SL is 117 microns, and the total arc length is 680 μm.

[0007] Another advantage of the present invention lies in providing a gold wire for a camera module. If two adjacent gold wires are inner arc gold wires, or two adjacent gold wires are outer arc wires, the discrimination criteria for double inner arc and double outer arc wire connections are as follows: the distance between the first solder joint is y1, the distance between the second solder joint is y2, take y0 = (y1 + y2) / 2, let the wire diameter be D, and the amplitudes of the two gold wires be A1 and A2 respectively. If A1 + A2 + D < y0, it is OK; if A1 + A2 + D ≥ y0, it is NG.

[0008] Another advantage of the present invention lies in providing a gold wire for a camera module. If one of two adjacent gold wires is an inner arc wire and the other gold wire is an outer arc wire, the discrimination criteria for inner and outer arc wire connections are as follows: the distance between the first solder joint is y1, the distance from the second solder joint of the inner arc to the outer arc is y3, take y0 = min(y1, y3), let the wire diameter be D, and the amplitudes of the two gold wires be A1 and A2 respectively. If A1 + A2 + D < y0, it is OK; if A1 + A2 + D ≥ y0, it is NG.

[0009] According to one aspect of the present invention, a gold wire for a camera module of the present invention that can achieve the foregoing and other objects and advantages, wherein the gold wire includes:

[0010] A first access end;

[0011] A second access end; and

[0012] A wiring end, wherein the wiring end connects the first access end and the second access end, the first access end extends obliquely downward from the wiring end, and the second access end extends vertically downward from the wiring end.

[0013] According to an embodiment of the present invention, the length of the wiring end of the gold wire is 25%S - 35% of the total length of the gold wire, and the length of the second access end is 80 - 160 um.

[0014] According to an embodiment of the present invention, the gold wire includes an inner arc gold wire and an outer arc gold wire. Let the length of the projection of the gold wire in the horizontal direction be the span L of the gold wire. Among them, the span L of the inner arc gold wire is less than 0.775 mm, and the span L of the outer arc gold wire is between 0.775 mm - 1 mm.

[0015] According to an embodiment of the present invention, the gold wire further includes a first solder joint and a second solder joint, wherein the first solder joint is formed at the first access end of the gold wire, and the second solder joint is formed at the second access end of the gold wire.

[0016] According to an embodiment of the present invention, for a double inner wire arc gold wire group composed of any two adjacent inner wire arc gold wires and a double outer wire arc gold wire group composed of any two adjacent outer wire arc gold wires, let the distance between the first solder joints of any two adjacent gold wires be y1, and let the distance between the second solder joints of any two adjacent gold wires be y2. Among them, take y0 = (y1 + y2) / 2, let the wire diameter of the gold wire be D, and the amplitudes of the two gold wires be A1 and A2 respectively; if A1 + A2 + D < y0, then there is no risk of wire bridging for the combination of the two gold wires, and if A1 + A2 + D ≥ y0, then there is a risk of wire bridging for the combination of the two gold wires.

[0017] According to an embodiment of the present invention, an inner wire arc gold wire and an outer wire arc gold wire are adjacent to form an inner-outer double wire arc gold wire group. The distance between the first solder joints of the inner-outer double wire arc gold wire group is y1, and the distance between the second solder joint of the inner wire arc and the outer wire arc gold wire is y3. Take y0 = min(y1, y3), let the wire diameter of the gold wire be D, and the amplitudes of the two gold wires be A1 and A2 respectively. If A1 + A2 + D < y0, then there is no risk of wire bridging for the inner-outer gold wire group composed of the two gold wires; if A1 + A2 + D ≥ y0, then there is a risk of wire bridging for the inner-outer gold wire group composed of the two gold wires.

[0018] According to an embodiment of the present invention, the wire diameter of the outer wire arc gold wire is 0.8 mil. When 0.775 mm < the projected length E of the gold wire < 1 mm, the safe distance y of the circuit board solder joint is 0.3 mm; when the projected length E of the gold wire < 0.775 mm, the safe distance y of the circuit board solder joint is 0.16 mm.

[0019] According to an embodiment of the present invention, when the wire diameter D of the gold wire is 0.9 mil, if 0.775 mm < the projected length E of the gold wire < 1 mm, the safe distance y of the circuit board solder joint is 0.26 mm; if the projected length E of the gold wire < 0.775 mm, the safe distance y of the circuit board solder joint is 0.12 mm.

[0020] According to an embodiment of the present invention, when the wire diameter D is 1 mil, if 0.775 mm < the projected length E of the gold wire < 1 mm, the safe distance y of the circuit board solder joint is 0.24 mm; if the projected length E of the gold wire < 0.775 mm, the safe distance y of the circuit board solder joint is 0.09 mm.

[0021] According to an embodiment of the present invention, the gold wire is a forward-facing gold wire or a backward-facing gold wire.

[0022] Through the understanding of the subsequent description and the drawings, the further objectives and advantages of the present invention will be fully realized.

[0023] These and other objectives, features and advantages of the present invention are fully realized through the following detailed description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 2 is a schematic diagram of a gold wire structure according to a first preferred embodiment of the present invention.

[0025] Figure 2 Schematic diagram of the stress-strain curve of the gold wire according to the preferred embodiment of the present invention.

[0026] Figure 3 2 is a schematic diagram of the results of the gold wire B / L&E / L test according to the preferred embodiment of the present invention.

[0027] Figure 4 2 is a schematic structural diagram of the gold wire according to the preferred embodiment of the present invention.

[0028] Figure 5 2 is a schematic diagram of the gold wire drop simulation according to the preferred embodiment of the present invention.

[0029] Figure 6 3 is a schematic diagram of the gold wire drop simulation according to the preferred embodiment of the present invention, wherein the span L of the gold wire is 0.313 mm.

[0030] Figure 7 3 is a schematic diagram of the gold wire drop simulation according to the preferred embodiment of the present invention, wherein the span L of the gold wire is 0.313 mm.

[0031] Figure 8 Schematic diagram of adjacent gold wires according to the preferred embodiment of the present invention.

[0032] Figure 9A It is a schematic structural diagram of adjacent gold wires in the prior art.

[0033] Figure 9B 3 is a schematic structural diagram of adjacent gold wires according to the preferred embodiment of the present invention.

[0034] Figure 10 Schematic diagram of the gold wire falling according to the preferred embodiment of the present invention.

[0035] Figure 11 Schematic diagram of amplitude detection in a structural drop test of adjacent gold wires in the prior art.

[0036] Figure 12 2 is a schematic diagram of amplitude detection of adjacent gold wire drop test according to the preferred embodiment of the present invention.

[0037] Figure 13A and Figure 13B Schematic diagram of different positions of adjacent gold wires according to the preferred embodiment of the present invention.

[0038] Figure 14 2 is a schematic diagram of amplitude detection at different positions of adjacent gold wires according to the preferred embodiment of the present invention.

[0039] Figure 15 This is the limit size of the solder joints of the inner and outer arc circuit boards of adjacent gold wires according to the above preferred embodiment of the present invention.

[0040] Figure 16 2 is a schematic diagram of simulation results when adjacent gold wire surfaces fall according to the preferred embodiment of the present invention.

[0041] Figure 17 3 is a schematic structural diagram of adjacent gold wires according to the preferred embodiment of the present invention.

[0042] Figure 18 This is the variation rule of the S-line arc safety distance y between adjacent gold wires according to the preferred embodiment of the present invention, where the projection line length E=1 mm. DETAILED DESCRIPTION

[0043] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are for illustrative purposes only, and those skilled in the art will readily appreciate other obvious variations. The basic principles of the present invention defined in the following description may be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0044] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0045] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the elements may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0046] Referring to the accompanying drawings of the present invention Figures 1 to 18As shown, a gold wire of a camera module according to a first preferred embodiment of the present invention is explained in the following description. The gold wire is used to connect a photosensitive chip and a circuit board of the camera module, wherein one end of the gold wire is soldered to the photosensitive chip and the other end of the gold wire is soldered to the circuit board, thereby achieving electrical connection between the photosensitive chip and the circuit board.

[0047] It is worth mentioning that in this preferred embodiment of the present invention, the present invention provides a gold wire line shape, wherein the gold wire line shape of the gold wire can effectively reduce the amplitude of the gold wire when the camera module falls, thereby reducing the impact of the camera module falling on the imaging performance, which is conducive to improving the service life of the camera module.

[0048] The gold wire includes a first access end 10, a second access end 20, and a connection end 30 located between the first access end 10 and the second access end 20. Preferably, the gold wire is an integrated structure, wherein the first access end 10 and the second access end 20 extend from one end of the connection end 30, respectively. The first access end 10 is electrically connected to the photosensitive chip, and the second access end 20 is electrically connected to the circuit board.

[0049] More preferably, in this preferred embodiment of the present invention, the second access end 20 of the gold wire is a vertical line segment, connected vertically to the circuit board, and the first access end 10 of the gold wire extends obliquely downward from the connection end 30 to the photosensitive chip. More preferably, the connection end 30 of the gold wire is connected between the first access end 10 and the second access end 20, and the connection end 30 is a horizontal structure, that is, the end of the connection end 30 connected to the second access end 20 extends vertically downward, and the end of the connection end 30 connected to the first access end 10 extends obliquely downward.

[0050] Assuming the total length of the gold wire is S, preferably, the length of the connection end 30 of the gold wire is 25%S to 35%S, and the length of the second access end 20 is 80 to 160 μm. In this preferred embodiment of the present invention, the gold wire includes at least one inner arc gold wire and at least one outer arc gold wire, wherein the inner arc gold wire and the outer arc gold wire have the same wire shape, but differ in length.

[0051] The gold wire further includes a first solder joint 40 and a second solder joint 50, wherein the first solder joint 40 is formed at the first access end 10 of the gold wire, and the second solder joint 50 is formed at the second access end 20 of the gold wire. The first solder joint 40 and the second solder joint 50 secure the first access end 10 and the second access end 20 of the gold wire.

[0052] Assuming the horizontal projection length of the gold wire is L, the span of the gold wire is less than 0.775 mm, and the span of the outer arc gold wire is between 0.775 mm and 1 mm. It is worth mentioning that in this preferred embodiment of the present invention, the length of the gold wire terminal 30 is adjustable to ensure that the distance between the gold wire and the chip is no less than one wire diameter, and the distance between the outer arc gold wire and the inner arc gold wire is no less than two wire diameters.

[0053] As an example, the length of the second access end 20 of the inner arc gold wire of the present invention is 75 μm, the length of the connection end is 45 μm, and the total length of the inner arc gold wire is 400 μm; the length of the second access end 20 of the outer arc gold wire of the present invention is 132 μm, the length of the connection end is 117 μm, and the total length of the inner arc gold wire is 600 μm. The material parameters of the gold wire are set as follows: diameter of 20 μm, density of 19.32 g / cm3, Poisson's ratio of 0.42, stress-strain curve as shown in Figure 2, elastic modulus of 70504.28 MPa, yield stress of 194.716 MPa, ultimate stress of 224.015 MPa, breaking stress of 220.269 MPa; B / L&E / L test is performed on the gold wire, as shown in Figure 2. Figure 3 As shown, the actual measurement results show that: 0.8mil gold wire BL: >6.0grf, EL: 2.0%-6.0%.

[0054] like Figure 5 As shown, the gold wire of the present invention was subjected to a first drop simulation test at a drop height of 1.5 meters. The wire diameter D was 0.8 mil, the height H of the second access end 20 of the wire was 0.08 mm / 0.1 mm / 0.12 mm, and the span L was 0.313 mm. When the height of the second access end 20 of the wire was 0.08 mm, the maximum amplitude of the wire was 0.0068 mm; when the height of the second access end 20 of the wire was 0.1 mm, the maximum amplitude of the wire was 0.0072 mm; and when the height of the second access end 20 of the wire was 0.12 mm, the maximum amplitude of the wire was 0.0082 mm. Therefore, it can be concluded that when the wire diameter D and span L remain unchanged, the higher the arc height H (i.e., the height of the second access end 20), the greater the wire amplitude.

[0055] like Figure 6 and Figure 7As shown, a second drop simulation test is carried out on the gold wire of the present invention, where the wire diameter D of the gold wire is 0.8 mil / 1 mil, the arc height H is 0.12 mm, and the span L is 0.313 mm / 0.67 mm. When the span L of the gold wire is 0.313 mm, the wire diameter D is 0.8 mil, the maximum amplitude of the gold wire is 0.0082 mm, and when the wire diameter D is 1 mil, the maximum amplitude of the gold wire is 0.007 mm; when the span L of the gold wire is 0.67 mm, the wire diameter D is 0.8 mil, the maximum amplitude of the gold wire is 0.032 mm, and when the wire diameter D is 1 mil, the maximum amplitude of the gold wire is 0.023 mm. Thus, it can be obtained that when the arc height H and the span L of the gold wire remain unchanged, the smaller the wire diameter D, the greater the amplitude of the gold wire, and the greater the span L, the more obvious the increase in the amplitude of the gold wire. When the arc height H and the wire diameter LD of the gold wire remain unchanged, the greater the span L, the greater the amplitude of the gold wire, and the greater the span L, the smaller the vibration frequency.

[0056] As Figure 8 shown, there are the following three situations for any two adjacent gold wires of the present invention, that is, an inner arc gold wire and an outer arc gold wire are adjacent to form an inner and outer double wire arc gold wire group; a double inner arc gold wire group formed by two adjacent inner arc gold wires; a double outer arc gold wire group formed by two adjacent outer arc gold wires. Let the distance between the first solder joints of any two adjacent gold wires be y1, let the distance between the second solder joints of any two adjacent gold wires be y2, and let the distance between the second solder joint of the inner arc and the outer arc gold wire be y3.

[0057] The present application further provides a method for judging wire connection of a gold wire group. The criteria for judging wire connection of the double inner arc gold wire group and the double outer arc gold wire group: take y0 = (y1 + y2) / 2, let the wire diameter of the gold wire be D, and the amplitudes of the two gold wires be A1 and A2 respectively; if A1 + A2 + D < y0, then there is no risk of wire connection for the combination of the two gold wires, and the gold wire group is judged as OK. If A1 + A2 + D ≥ y0, then there is a risk of wire connection for the combination of the two gold wires, and it is judged as NG. The criteria for judging wire connection between the inner and outer arcs: take y0 = min(y1, y3), let the wire diameter of the gold wire be D, and the amplitudes of the two gold wires be A1 and A2 respectively. If A1 + A2 + D < y0, then there is no risk of wire connection for the inner and outer gold wire group formed by the two gold wires, and it is judged as OK; if A1 + A2 + D ≥ y0, then there is a risk of wire connection for the inner and outer gold wire group formed by the two gold wires, and it is judged as NG.

[0058] As Figures 9A to 10 shown, a drop test is carried out on the gold wire group of the prior art and the gold wire group improved by the present application. As Figure 9AA gold wire set of the prior art is shown, in which the 42# and 43# gold wires of the set are both long wire arcs, i.e., outer wire arc gold wires. The height of the second access end of the 42# gold wire is 0.12mm, the length of the connection end is 25%S, the span L is 0.555mm, the wire bonding angle is 34°, and the wire diameter D is 0.8mil; the second access end of the 43# gold wire is 0.12mm, the connection end is 25%S, the span L is 0.555mm, the wire bonding angle is 32°, and the wire diameter D is 0.8mil, where S is the total length of the gold wire.

[0059] like Figure 10 As shown, a drop test is performed on a drop box of a camera module with the gold wire, wherein the camera module is set in the drop box, and the risk of the gold wire in the drop box being wired is tested in different drop directions.

[0060] like Figure 11 As shown in the figure, the amplitudes of the gold wires with corner drops and surface drops are larger; the measured y1=0.1mm, y2=0.18mm, y0=(y1+y2) / 2=0.14mm, the amplitude of gold wire No. 42 is A1=0.056mm, the amplitude of gold wire No. 43 is A2=0.084mm, according to the double inner arc and double outer arc overlap criteria, gold wires No. 42 and No. 43 have overlap risks, which is consistent with the measured results, and the overlap positions are basically consistent. The simulation results are consistent with the measured results.

[0061] like Figure 9B As shown in the figure, simulations were conducted on the optimized gold wires #42 and #43. The optimized wire arc geometric parameters are as follows: For the #42 gold wire, the second access end height is 0.12mm, the terminal length is 35% of S, the span L is 0.373mm, the bonding angle is 51°, and the wire diameter D is 0.8mil. For the #43 gold wire, the second access end height is 0.12mm, the terminal length is 35% of S, the span L is 0.373mm, the bonding angle is 43°, and the wire diameter D is 0.8mil, where S is the total wire length. The drop directions are the same: flat drop and corner drop.

[0062] like Figure 12 As shown in the figure, the amplitudes of the gold wires with corner drop and surface drop are compared. The amplitude of the surface drop is larger, and the specific amplitude is shown in Figure 12. It is known that y1=0.1mm and y2=0.192mm are measured, and y0=(y1+y2) / 2=0.146mm is taken. After simulation, the amplitude of gold wire No. 42 is A1=0.015mm, and the amplitude of gold wire No. 43 is A2=0.018mm. According to the double inner arc and double outer arc overlap judgment criteria, gold wires No. 42 and No. 43 have no overlap risk, which is consistent with the measured results. The simulation results are consistent with the measured results.

[0063] To verify the above results, several other sets of gold wires with longer and closer arcs (measured OK) were selected from the gold wires of the same camera module and subjected to drop simulation to verify whether the simulated wire bonding critical points are consistent with the actual measurements. The gold wires 15# & 16# (inner and outer arcs), 34# & 35# (double outer arcs), 43# & 44# (double outer arcs), 50# & 51# (double outer arcs), and 174# & 175# (double outer arcs) were selected, and the drop direction was flat. The specific simulation results are shown in the following table:

[0064]

[0065] All five simulation results show no NG alignment, which is consistent with actual measurements. The alignment simulation predictions are accurate and reliable. Therefore, the table above shows that the probability of alignment for double outside arcs is much higher than for double inside and inside-outside arcs.

[0066] Figures 13A to 14 The gold wire structures at different positions and angles are shown, and a simulated drop test is performed on each of the gold wire structures. Figure 13A As shown in the figure, there are four gold wire structures in different positions, where the arc height and span of the gold wire structure are both set to the limit, the wire bonding angle is temporarily set at 90°, and the drop simulation settings are the same as before to determine the influence of the gold wire position on the amplitude. The geometric parameters of the outer wire arc are: the height of the second access end is 0.16mm, the length of the connection end is 0.25mm, the span L is 1mm, the wire bonding angle is 90°, and the wire diameter D is 0.8mil; the drop direction is surface drop. After simulation, it is found that the gold wire swings at positions 1, 2, 3, and 4 are basically the same, with an amplitude of 0.094mm. Therefore, the gold wire position has no effect on the amplitude. Figure 13B As shown in the figure, gold wires with different bonding angles are simulated to find the relationship between amplitude and bonding angle. The outer arc geometric parameters are: the height of the second access end is 0.16mm, the length of the terminal is 0.25mm, the projection line length E is 1mm, the bonding angle is 90° / 67.5° / 45° / 37.5°, the wire diameter D is 0.8mil; the drop direction is flat drop, and the simulation results are as follows: Figure 14 As shown in the figure, it can be obtained that the bonding angle has no obvious effect on the gold wire amplitude, and the gold wire amplitudes of the four groups of bonding angles are all around 0.09mm.

[0067] like Figure 15 The maximum size of the solder joints of the inner arc gold wire and the outer arc circuit board of the preferred embodiment of the present invention is shown in the figure, which has the following size relationship, wherein the minimum difference between the inner and outer arc spans is 0.225mm, and the maximum span of the inner arc is 0.775mm. Figure 16The drop simulation test of the inner arc gold wire is shown as follows. The geometric parameters of the inner arc gold wire are as follows: the height of the second access end is 0.12 mm, the length of the wiring end is 0.25 mm, the length of the projection line E is 0.775 mm, the wire bonding angles are 90° / 67.5° / 45° / 37.5°, and the wire diameter D is 0.8 mil. The drop direction is face drop. It can be obtained that the wire bonding angle has no obvious influence on the amplitude of the gold wire, and the amplitudes of the four groups of wire bonding angles are all about 0.055 mm.

[0068] Based on the above simulation results of the gold wire, the following conclusions are obtained. The amplitude of the gold wire drop is independent of the wire bonding position and the wire bonding angle; the amplitude of the gold wire drop is related to the wire diameter, wire shape and the length of the gold wire. Preferably, for the outer arc gold wire with a wire diameter of 0.8 mil, when 0.775 mm < the projection length E of the gold wire < 1 mm, the safety distance y of the circuit board solder joint is 0.3 mm; when the projection length E of the gold wire < 0.775 mm, the safety distance y of the circuit board solder joint is 0.16 mm.

[0069] Next, for different wire diameters and lengths of the gold wire arc, the safety distance y of the circuit board solder joint is tested respectively. The method is the same as before, and the conclusions are as follows: when the wire diameter D of the gold wire is 0.9 mil, if 0.775 mm < the projection length E of the gold wire < 1 mm, the safety distance y of the circuit board solder joint is 0.26 mm; if the projection length E of the gold wire < 0.775 mm, the safety distance y of the circuit board solder joint is 0.12 mm. When the wire diameter D is 1 mil, if 0.775 mm < the projection length E of the gold wire < 1 mm, the safety distance y of the circuit board solder joint is 0.24 mm; if the projection length E of the gold wire < 0.775 mm, the safety distance y of the circuit board solder joint is 0.09 mm. In the current design specification, the minimum value of y is 0.175 mm. When 0.775 mm < E < 1 mm of the gold wire projection length, the safety distance y is greater than 0.175 mm. The safety distance y needs to be determined according to the above conclusions, which is consistent with the measured conclusions.

[0070] It is worth mentioning that the above gold wire arcs are all positive wire bonding arcs, that is, the first solder joint of the gold wire is set on the photosensitive chip, the second solder joint of the gold wire is set on the circuit board, and the second access end 20 of the gold wire is perpendicular to the circuit board.

[0071] The following is a simulation test on the reverse wire arc of the gold wire. The difference between the reverse wire arc and the forward wire arc of the gold wire is that the first solder joint of the reverse wire arc of the gold wire is set on the circuit board, and the second access end 20 of the gold wire is perpendicular to the pad. The geometric parameters of the reverse wire arc of the gold wire are as follows: the height of the second access end is 0.09 mm, the length of the connection end is 0.25 mm, the projected wire length E of the gold wire is 1 mm / 0.775 mm, the wire bonding angle is 45°, and the wire diameter D of the gold wire is 0.8 mil / 0.9 mil / 1 mil (where the height of the second access end is based on the higher one of the chip and the circuit board).

[0072] The simulation results are as follows in the table:

[0073]

[0074] It is worth mentioning that the following conclusions can be obtained from the test results in the above table. The swing of the reverse wire arc of the gold wire is smaller than that of the forward wire arc of the gold wire, and the swing amount of the sinking reverse wire arc of the gold wire is the smallest. As Figure 18 shown, the larger the wire diameter of the gold wire, the smaller the safety distance to be reserved. And when the gold wire is bonded forward, when the wire diameter increases from 0.8 mil to 1 mil, the safety distance decreases from 0.3 mm to 0.24 mm; when the gold wire is bonded in reverse, when the wire diameter increases from 0.8 mil to 1 mil, the safety distance decreases from 0.26 mm to 0.18 mm; when the gold wire is sunk and bonded in reverse, when the wire diameter increases from 0.8 mil to 1 mil, the safety distance decreases from 0.12 mm to 0.09 mm. The swing of the reverse wire arc of the gold wire is smaller than that of the forward wire arc of the gold wire, and the swing amount of the sinking reverse wire arc is the smallest. Therefore, the safety distance to be reserved for the reverse wire arc of the gold wire is the smallest. In the current design specification, the minimum value of y is 0.175 mm. When 0.775 mm < E < 1 mm for the projected length of the forward gold wire, the safety distance y is greater than 0.175 mm, and the safety distance y needs to be determined according to the above conclusions. When 0.775 mm < E < 1 mm for the non-sinking reverse bonding of the gold wire, the safety distance y is greater than 0.175 mm, and the safety distance y needs to be determined according to the above conclusions. The safety distance y of the sinking reverse wire arc of the gold wire is less than 0.175 mm, and it can be designed according to the current specification.

[0075] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the drawings are only examples and do not limit the present invention. The object of the present invention has been completely and effectively achieved. The function and structural principle of the present invention have been shown and explained in the embodiments. Without departing from the said principle, the embodiments of the present invention can have any deformation or modification.

Claims

1. A gold wire for a camera module, characterized in that: The gold wire includes: A first access end; A second access end; and A wiring end, wherein the wiring end connects the first access end and the second access end. The first access end extends obliquely downward from the wiring end, and the second access end extends vertically downward from the wiring end. The length of the wiring end of the gold wire is 25% - 35% of the total length of the gold wire, and the length of the second access end is 80 - 160 um. The gold wire includes an inner arc gold wire and an outer arc gold wire. A double inner arc gold wire group is formed by any two adjacent inner arc gold wires, and a double outer arc gold wire group is formed by any two adjacent outer arc gold wires. Let the distance between the first solder joints of any two adjacent gold wires be y1, and let the distance between the second solder joints of any two adjacent gold wires be y2. Take y0 = (y1 + y2) / 2. Let the wire diameter of the gold wire be D, and the amplitudes of the two gold wires be A1 and A2 respectively; if A1 + A2 + D < y0, then there is no risk of wire bridging for the combination of the two gold wires; if A1 + A2 + D ≥ y0, then there is a risk of wire bridging for the combination of the two gold wires.

2. The gold wire according to claim 1, wherein the length of the projection of the gold wire in the horizontal direction is the span L of the gold wire. The span L of the inner arc gold wire is less than 0.775 mm, and the span L of the outer arc gold wire is between 0.775 mm and 1 mm.

3. The gold wire according to claim 1, wherein the gold wire further includes a first solder joint and a second solder joint. The first solder joint is formed at the first access end of the gold wire, and the second solder joint is formed at the second access end of the gold wire.

4. The gold wire according to claim 2, wherein an inner arc gold wire and an outer arc gold wire are adjacent to form an inner and outer double arc gold wire group. The distance between the first solder joints of the inner and outer double arc gold wire group is y1, and the distance between the second solder joint of the inner arc and the outer arc gold wire is y3. Take y0 = min(y1, y3). Let the wire diameter of the gold wire be D, and the amplitudes of the two gold wires be A1 and A2 respectively. If A1 + A2 + D < y0, then there is no risk of wire bridging for the inner and outer gold wire group formed by the two gold wires; if A1 + A2 + D ≥ y0, then there is a risk of wire bridging for the inner and outer gold wire group formed by the two gold wires.

5. The gold wire according to claim 2, wherein the wire diameter of the outer arc gold wire is 0.8 mil. When 0.775 mm < the projection length E of the gold wire < 1 mm, the safe distance y of the circuit board solder joint is 0.3 mm; when the projection length E of the gold wire < 0.775 mm, the safe distance y of the circuit board solder joint is 0.16 mm.

6. The gold wire according to claim 2, wherein when the wire diameter D of the gold wire is 0.9 mil, if 0.775 mm < the projection length E of the gold wire < 1 mm, the safe distance y of the circuit board solder joint is 0.26 mm; if the projection length E of the gold wire < 0.775 mm, the safe distance y of the circuit board solder joint is 0.12 mm.

7. The gold wire according to claim 2, wherein when the wire diameter D is 1 mil, if 0.775 mm < gold wire projection length E < 1 mm, the circuit board solder joint safety distance y is 0.24 mm; if the gold wire projection length E < 0.775 mm, the circuit board solder joint safety distance y is 0.09 mm. The gold wire according to claim 2 , wherein the gold wire is a forward-punched gold wire or a reverse-punched gold wire.

9. The gold wire according to claim 2, wherein the length of the second access end of the inner arc gold wire is 75 μm, the length of the connection end of the inner arc gold wire is 45 μm, and the total length of the inner arc gold wire is 400 microns, wherein the length of the second access end of the outer arc gold wire is 132 μm, the length of the connection end of the outer arc gold wire is 117 μm, and the total length of the outer arc gold wire is 600 microns.

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