Automatic gold ribbon bonding method for multi-chip microwave assembly

Abstract

The application discloses an automatic gold ribbon bonding method for a multi-chip microwave assembly, relates to the field of wire bonding technology, and is used for improving the automation degree, production efficiency and bonding consistency of gold ribbon bonding in the multi-chip assembly. The method comprises the following operations: bonding wedge selection, clamp size design, bonding parameter setting, wedge wiring track parameter setting, ceramic sample pressure test, plasma cleaning, assembly clamping, automatic gold ribbon bonding in a large-span high-fall area and the like. The method has the advantages of simple operation and high efficiency, can realize automatic bonding of the gold ribbon without changing the layout of internal components and the structure of the box body of the multi-chip microwave assembly, meets the high-efficiency interconnection requirement of the multi-chip microwave assembly, and has high practicability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wire bonding, in particular to an automatic gold ribbon bonding method for multi-chip microwave assemblies. BACKGROUND

[0002] Gold ribbon bonding is an important process method for realizing electrical interconnection of multi-chip microwave assemblies, which allows large power current that cannot be carried by general gold wires. With the development of weapon systems towards miniaturization and high performance, the integration density and current power of microwave assemblies are continuously improved, and the application of gold ribbon bonding is more and more widely, which puts forward higher requirements for its production efficiency and reliability.

[0003] In the prior art, due to the fact that the size of the gold ribbon is generally large, the gold ribbon bonding cannot be realized automatically, and manual bonding operation is generally adopted, which not only seriously restricts the efficiency of gold ribbon bonding, but also the reliability varies from person to person. Therefore, to realize the automation of gold ribbon bonding can not only greatly improve the production efficiency, but also improve the consistency of products, which is the preferred choice for the gold ribbon bonding process in the future. SUMMARY

[0004] The present application aims to provide a multi-chip microwave assembly automatic gold ribbon bonding method which is simple to operate and can realize automatic gold ribbon bonding without greatly changing the original equipment structure, meets the high-efficiency gold ribbon interconnection demand of multi-chip microwave assemblies, and solves the technical problems of low efficiency and poor consistency of manual operation of gold ribbon bonding in the prior art.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] The present application provides a multi-chip microwave assembly automatic gold ribbon bonding method, comprising the following steps:

[0007] Step S1, according to the gold ribbon specification, complete the selection of bonding wedge;

[0008] Step S2, according to the gold ribbon specification, design the size of the wire clamp;

[0009] Step S3, according to the gold ribbon specification, complete the bonding parameter setting;

[0010] Step S4, complete the wedge wire trace parameter setting;

[0011] Step S5, based on the setting parameters and equipment selection in steps S1-S4, perform ceramic sample pressure test;

[0012] Step S6, after the pressure test, perform plasma cleaning of the bonding surface of the multi-chip microwave assembly;

[0013] Step S7, assemble and clamp the cleaned multi-chip microwave assembly into position;

[0014] Step S8, complete the automatic gold ribbon bonding at a speed of 2 gold ribbons per second.

[0015] In some embodiments, the gold ribbon specification is 100um-250um in width and 12.7um-25.4um in thickness.

[0016] In some embodiments, the length of the wedge tip is greater than the width of the gold ribbon when the wedge is selected, the length of the wedge tip W is 216um-648um, the width of the wedge tip BL is 50um-100um, and the outer end face taper angle MTA of the wedge is 20°-30°.

[0017] In some embodiments, the wire clamp is designed to have a clamp tip width B of 250um-300um and a clamp thickness T of 0.5mm-1mm.

[0018] In some embodiments, the bonding parameters include a wedge impedance value of 17Ohm-26Ohm, a wedge resonance frequency of 89KHz-94KHz, a bonding ultrasonic time of 210ms-250ms, a bonding pressure of 200g-250g, and an ultrasonic power of 2.57W-2.98W.

[0019] In some embodiments, the wedge trace trajectory parameters include: (1) vertically pulling up the wedge by a distance of 500um-600um to provide space for the wedge trace; (2) climbing at an upward angle B1 of 20°-30°, with a gentle curvature of 60um and a climbing height of 200um-250um; (3) descending the wedge at a downward angle B2 of 20°-30°, with a descending height of 50um-150um to complete the pre-shaping of the gold ribbon curvature; and (4) vertically dropping the wedge by a distance of 650um-750um to complete the shaping of the gold ribbon arch.

[0020] In some embodiments, the ceramic sample is pressure tested, including:

[0021] First, 10 gold ribbons are pressure welded on the ceramic sample using the set parameters and equipment, and the 10 gold ribbons are bonded in a row;

[0022] The distance between adjacent gold ribbons is 250um.

[0023] Then, the tensile strength of the bonded gold ribbons is detected to verify the effect of the automatic gold ribbon bonding after the parameter setting and selection in steps S1-S4.

[0024] In some embodiments, the bonding surface of the multi-chip microwave assembly is plasma cleaned, including:

[0025] The plasma power is set to 300W-600W.

[0026] The cleaning time is set to 1-3 minutes;

[0027] The multi-chip microwave assembly bonding surface is plasma cleaned according to the set power and time.

[0028] In some embodiments, the cleaned multi-chip microwave assembly is assembled into position, including:

[0029] The multi-chip microwave assembly is placed on the surface of the heating table;

[0030] The multi-chip microwave assembly is fixed by the tooling;

[0031] The temperature of the heating table is set to 90-100 DEG C to provide a bottom temperature for gold ribbon bonding.

[0032] In some embodiments, the automatic gold ribbon bonding method has a maximum span of the bonding area of 3 mm and a maximum height difference of the bonding area of 2 mm.

[0033] Compared with the prior art, the present application has the following beneficial effects:

[0034] The automatic gold ribbon bonding method for the multi-chip microwave assembly has the advantages of simple operation and high efficiency, and can realize automatic bonding of the gold ribbon without changing the layout of internal components and the structure of the box body, thereby meeting the demand for efficient production of the multi-chip microwave assembly. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 A gold ribbon bonding effect diagram of the automatic gold ribbon bonding method for the multi-chip microwave assembly provided by the embodiment of the present application;

[0036] Figure 2 A main view of a cleaver in the automatic gold ribbon bonding method for the multi-chip microwave assembly provided by the embodiment of the present application;

[0037] Figure 3 An end view of the cleaver in the automatic gold ribbon bonding method for the multi-chip microwave assembly provided by the embodiment of the present application;

[0038] Figure 4 A main view of a wire clamp in the automatic gold ribbon bonding method for the multi-chip microwave assembly provided by the embodiment of the present application;

[0039] Figure 5 A side view of the wire clamp in the automatic gold ribbon bonding method for the multi-chip microwave assembly provided by the embodiment of the present application;

[0040] Figure 6 A cleaver wire trace schematic diagram of the automatic gold ribbon bonding method for the multi-chip microwave assembly provided by the embodiment of the present application;

[0041] Figure 7 A flow chart of a multi-chip microwave assembly automatic gold ribbon bonding method is provided for the embodiments of the present application. DETAILED DESCRIPTION

[0042] Example embodiments will be described more fully hereinafter with reference to the accompanying drawings, in which example embodiments can be embodied as many different forms and should not be construed as limited to the implementation set forth herein. Rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

[0043] In the case of no conflict, each feature in the embodiments of the application and the embodiments can be combined with each other.

[0044] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0045] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0046] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an overly literal or overly formal sense unless expressly so defined herein.

[0047] In order to realize the automation of gold ribbon bonding, the embodiments of the present application provide a multi-chip microwave assembly automatic gold ribbon bonding method. In order to enable those skilled in the art to better understand the technical solutions, the multi-chip microwave assembly automatic gold ribbon bonding method provided by the present application will be described in detail below with reference to the accompanying drawings.

[0048] As shown in Figure 7 The present application provides a multi-chip microwave assembly automatic gold ribbon bonding method, which comprises the following steps:

[0049] Step S1, according to the gold ribbon specification, the bonding wedge selection is completed; the end head specification of the bonding wedge should be greater than the gold ribbon specification, so as to completely cover the gold ribbon; by designing the size of the wedge end head, the gold ribbon pad area is controlled, and the one-time bonding can meet the tensile strength requirement without multiple bonding;

[0050] Specifically, in the embodiment, the gold ribbon has a width of 100um-250um (4mil-10mil) and a thickness of 12.7um-25.4um (0.5mil-1mil). Due to the limitations of the equipment power, the wedge and the wire clip specifications, the gold ribbon with a width of 100um-250um (4mil-10mil) is taken as an example for specific description.

[0051] As shown in Figure 2 and Figure 3 When the gold ribbon with the above specifications is used, the length of the wedge tip needs to be greater than the width of the gold ribbon when the wedge is selected. Therefore, in the embodiment, the wedge with a tip length W of 216um-648um is selected, the wedge with a tip width BL of 50um-100um is selected, and the outer end face taper angle MTA of the wedge is 20°-30°.

[0052] Step S2, the wire clip size is designed according to the gold ribbon specification; the wire clip size should be set according to the gold ribbon specification to ensure that the wire clip can completely fix and clamp the gold ribbon;

[0053] As shown in Figure 4 and Figure 5 It should be noted that in the embodiment, the wire clip is improved on the basis of the traditional gold wire bonding clip. When the above gold ribbon specification is used, in order to ensure that the wire clip is not easily deformed and can maintain a suitable clamping degree, the wire clip tip width B of the present application is selected to be between 250um-300um (10mil-12mil), and the wire clip thickness T is selected to be between 0.5mm-1mm (20mil-40mil), so as to effectively fix and break the gold ribbon.

[0054] Step S3, the bonding parameters are set according to the gold ribbon specification;

[0055] Further, according to the above gold ribbon specification, the selected wedge is assembled to the automatic bonding equipment, and the bonding parameter setting includes that the impedance value of the bonding wedge is between 17Ohm-26Ohm, the wedge resonance frequency is between 89KHz-94KHz, the wedge vibration amplitude is maximized during the bonding process. The bonding ultrasonic time is set to 210ms-250ms, the bonding pressure is set to 200g-250g, and the ultrasonic power is set to 2.57W-2.98W. Large ultrasonic, large pressure, and large power are applied in the way of spot welding rather than wedge welding to realize the bonding of the gold ribbon.

[0056] Step S4, the wedge wiring track parameter setting (arch parameter setting) is completed;

[0057] As shown in Figure 6As shown, the cleaver routing track parameter setting includes: (1) the cleaver vertically pulls up, and the vertical rising distance is between 500um and 600um, which provides space for the cleaver routing; (2) the cleaver climbs up at an angle B1 between 20 and 30 degrees, the smoothing radius is 60um, the climbing height is between 200um and 250um, and the overall height (Height apex) is between 700um and 850um; (3) the cleaver cuts down at an angle B2 between 20 and 30 degrees, and the falling height is between 50um and 150um, which completes the gold ribbon arc pre-forming; (4) the cleaver vertically falls a distance (Destination height) between 650um and 750um, which completes the gold ribbon arch forming.

[0058] Step S5, based on the setting parameters and equipment selection in steps S1-S4, the ceramic sample is pressure tested;

[0059] Specifically, first, 10 gold ribbons are pressure welded on the ceramic sample using the set parameters and equipment, and the 10 gold ribbons are bonded in a row;

[0060] The distance between adjacent gold ribbons is 250um;

[0061] Then, the tensile strength of the bonded gold ribbons is detected to verify the effect of automatic gold ribbon bonding after the parameter setting and selection in steps S1-S4.

[0062] It should be noted that the distance of 250um between adjacent gold ribbons is based on two considerations, one is to simulate high-density integration effect to verify whether the gold ribbon bonding has an impact on each other based on high-density integration, and the second is because the distance between the commonly used gold ribbons is 250um, so this commonly used distance is used as a detection parameter, and the tensile strength test is performed after bonding to verify whether the parameters set in the previous steps and the equipment selection are appropriate, and to verify the effect of automatic gold ribbon bonding.

[0063] Step S6, after the pressure test is completed, the bonding surface of the multi-chip microwave assembly is plasma cleaned to improve the activity of the bonding surface;

[0064] First, set the plasma power to 300W-600W;

[0065] Then, set the cleaning time to 1min-3min;

[0066] Finally, the bonding surface of the multi-chip microwave assembly is plasma cleaned according to the set power and time.

[0067] After cleaning, prepare for clamping and bonding.

[0068] Step S7, the cleaned multi-chip microwave assembly is assembled to the position;

[0069] The multi-chip microwave assembly is placed on the surface of the heating table;

[0070] The multi-chip microwave assembly is fixed by the tool to prevent vibration caused by high power application, which causes program deviation, and the assembly is required to be placed horizontally on the surface of the heating table;

[0071] The temperature of the heating table is set to 90-100 DEG C to provide a bottom temperature for gold ribbon bonding.

[0072] Step S8, the automatic gold ribbon bonding is completed at a speed of 2 gold ribbons per second.

[0073] The automatic gold ribbon bonding method has a maximum span of 3 mm in the bonding area, and a maximum difference of 2 mm in the bonding area.

[0074] As shown in Figure 1 FIG. 1 is an automatic gold ribbon bonding effect diagram of the multi-chip microwave assembly after the automatic gold ribbon bonding method is used to bond the gold ribbon.

[0075] The automatic gold ribbon bonding method for the multi-chip microwave assembly has the advantages of simple operation and high efficiency, and can realize automatic bonding of the gold ribbon without changing the layout of the internal components of the multi-chip microwave assembly and the structure of the box body, thereby meeting the demand of the multi-chip microwave assembly for high efficiency production.

[0076] Example embodiments have been disclosed herein and, although the use of specific terms is exemplified throughout, they are used in this context only and are not intended to limit the application in any way. In some embodiments, it will be apparent to one of ordinary skill in the art that features, characteristics, and / or elements described in connection with a particular embodiment can be used in conjunction with other embodiments unless otherwise explicitly stated. Accordingly, one of ordinary skill in the art will understand that various changes in form and detail can be made without departing from the scope of the application as set forth in the appended claims.

Claims

1. A method for automated gold ribbon bonding of a multi-chip microwave assembly, characterized in that, Includes the following steps: Step S1: Select the bonding cutter according to the gold strip specifications; Step S2: Design the wire clamp size according to the gold strip specifications; Step S3: Set the bonding parameters according to the gold strip specifications; Step S4: Complete the parameter settings for the cutting tool trajectory; Step S5: Based on the settings and equipment selection in steps S1-S4, perform pressure testing on the ceramic sample; Step S6: After the pressure test is completed, perform plasma cleaning on the bonding surface of the multi-chip microwave component. Step S7: Install the cleaned multi-chip microwave assembly into place; Step S8: Complete automatic gold strip bonding at a rate of 2 gold strips per second; The parameters for the cutting tool's trajectory are set as follows: (1) The cutting tool is pulled vertically upward, with a vertical rise distance of 500um to 600um, to provide space for the cutting tool's trajectory; (2) The cutting tool is raised at an upward angle of 20 to 30° (B1), with a gentle curvature of 60um and a rise height of 200um to 250um; (3) The cutting tool is lowered at a downward angle of 20 to 30° (B2), with a fall height of 50um to 150um, to complete the pre-forming of the gold strip's arc; (4) The cutting tool is lowered vertically at a distance of 650um to 750um, to complete the forming of the gold strip's arch. Perform pressure testing on ceramic samples, including: First, using the set parameters and equipment, 10 gold strips are pressure-welded onto the ceramic sample, and the 10 gold strips are bonded in a row. The distance between adjacent gold bands is 250 μm; Then, the tensile strength of the bonded gold strip is tested to verify the automatic gold strip bonding effect after parameter settings and selection in steps S1-S4.

2. The automatic gold strip bonding method for multi-chip microwave components according to claim 1, characterized in that, The gold strip specifications are 100um to 250um in width and 12.7um to 25.4um in thickness.

3. The automatic gold strip bonding method for multi-chip microwave components according to claim 2, characterized in that, When selecting a bonding cleaver, the length of the cleaver end should be greater than the width of the gold strip. The length W of the cleaver end should be 216um to 648um, the width BL of the cleaver end should be 50um to 100um, and the outer end face cone angle MTA of the cleaver should be 20° to 30°.

4. The automatic gold strip bonding method for multi-chip microwave components according to claim 2, characterized in that, The wire clamp dimensions are designed with a wire clamp end width B of 250um to 300um and a wire clamp thickness T of 0.5mm to 1mm.

5. The automatic gold strip bonding method for multi-chip microwave components according to claim 2, characterized in that, The bonding parameters are set as follows: bonding wedge impedance value of 17 Ohm to 26 Ohm, wedge resonant frequency of 89 kHz to 94 kHz, bonding ultrasonic time of 210 ms to 250 ms, bonding pressure of 200 g to 250 g, and ultrasonic power of 2.57 W to 2.98 W.

6. The automatic gold strip bonding method for multi-chip microwave components according to claim 1, characterized in that, Plasma cleaning of the bonding surfaces of multi-chip microwave components includes: Set the plasma power to 300W-600W; Set the cleaning time to 1 to 3 minutes; Plasma cleaning is performed on the bonding surfaces of multi-chip microwave components according to the set power and time.

7. The automatic gold strip bonding method for multi-chip microwave components according to claim 1, characterized in that, Install the cleaned multi-chip microwave assembly into place, including: The multi-chip microwave assembly is placed on the upper surface of the heating stage; The multi-chip microwave assembly is fixed using tooling; The heating stage temperature is set to 90℃~100℃ to provide a low temperature for gold strip bonding.

8. The automatic gold strip bonding method for multi-chip microwave components according to claim 1, characterized in that, The automatic gold strip bonding method processes a bonding area with a maximum span of 3 mm and a maximum drop of 2 mm.

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