Fixing assembly
By combining a support plate, positioning pins, and positioning caps, the problem of conductive clip shifting during high-temperature sintering was solved, achieving high-precision fixing of the conductive clip and lead frame and improving product yield.
Patent Information
- Application Number
- CN202423291573.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2025-12-23
- Estimated Expiration
- 2034-12-30
AI Technical Summary
During the high-temperature sintering process of semiconductor products, the conductive clips are prone to shifting relative to the lead frame, affecting product yield.
The structure employs a combination of support plate, positioning pin, and positioning cap. The conductive clip and lead frame are fixed by three-point positioning, which restricts the relative movement of their stacking direction and ensures fixing accuracy.
It improves the fixing accuracy of conductive clips and lead frames, reduces offset, and improves product yield.
Smart Images
Figure CN223712749U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of semiconductor, and in particular to a fixing assembly. BACKGROUND
[0002] In the process of manufacturing some semiconductor products, a chip is bonded on a lead frame, and a conductive clip is bonded behind the chip. A wire (such as a gold wire or an aluminum wire) is needed to be used to wire-bond the pads on the chip to the corresponding pads on the lead frame or substrate. After the wire bonding is completed, in order to enhance the mechanical strength and electrical performance of the bonding points, a high-temperature sintering process is usually needed to be performed on the semiconductor intermediate assembly formed after the wire bonding. During the high-temperature sintering process, the conductive clip is prone to deviate relative to the lead frame, which affects the yield of the product. It is crucial to fix the conductive clip and the lead frame to reduce the deviation of the conductive clip. SUMMARY
[0003] Embodiments of the present application provide a fixing assembly for fixing a lead frame and at least one conductive clip in an intermediate semiconductor assembly to be subjected to high-temperature sintering. Each of the conductive clips has a conductive clip positioning hole for a previous process on opposite sides. The lead frame has a lead frame positioning hole for a previous process on opposite sides. The fixing assembly comprises:
[0004] a support plate having opposite first and second sides, wherein the first and second sides of the support plate are each provided with a support plate positioning hole; each of the support plate positioning holes corresponds to a conductive clip positioning hole for a previous process and a lead frame positioning hole for a previous process;
[0005] a plurality of positioning needles respectively matched with one of the support plate positioning holes, wherein each of the conductive clips is fixed by only three positioning needles, at least one of the support plate positioning holes matched by the three positioning needles for fixing each of the conductive clips is located on the first side, and at least one is located on the second side; each of the positioning needles can be arranged in a conductive clip positioning hole and a corresponding lead frame positioning hole, and one end of each of the positioning needles is inserted into a corresponding support plate positioning hole;
[0006] a plurality of first type positioning caps, which are arranged on the ends of the positioning needles away from the support plate positioning holes, so as to limit the relative movement of the conductive clip and the lead frame in the stacking direction of the conductive clip and the lead frame.
[0007] In some embodiments, the positioning needles are stainless steel needles.
[0008] In some embodiments, the deviation of the positioning needles in the lead frame positioning hole and the corresponding conductive clip positioning hole is less than or equal to 0.01 mm.
[0009] In some embodiments, the support plate is a heat-conducting plate.
[0010] In some embodiments, the support plate is a graphite plate or a stainless steel plate.
[0011] In some embodiments, the size of the support plate positioning hole in the thickness direction of the support plate is less than or equal to 2 / 3 of the thickness of the support plate.
[0012] In some embodiments, the first type of positioning cap is provided with a first cap hole for cooperating with the positioning needle.
[0013] In some embodiments, the fixing assembly further comprises a second type of positioning cap which is replaceable with the first type of positioning cap for cooperating with the positioning needle, and the second type of positioning cap is provided with a second cap hole for cooperating with the support plate positioning hole; wherein the depth of the first cap hole and the depth of the second cap hole are different.
[0014] In some embodiments, the conductive clamp comprises a plurality of conductive clamp sub-units, each of which corresponds to one chip for electrically leading out the corresponding chip.
[0015] In some embodiments, the length of the positioning needle is 0.6-0.7mm;
[0016] The thickness of the support plate is 0.10-0.50mm;
[0017] The size of the positioning hole in the thickness direction of the support plate is 0.10-0.50mm.
[0018] The main technical effects achieved by the embodiments of the present application are:
[0019] The fixing assembly provided by the embodiments of the present application sets the fixing assembly to comprise a support plate, a plurality of positioning needles and a plurality of first type of positioning caps. Each conductive clamp is fixed by only three positioning needles and the lead frame, three-point positioning is achieved in the direction perpendicular to the stacking direction of the lead frame and the conductive clamp, and the first type of positioning cap is cooperated to achieve the relative movement of the lead frame and the conductive clamp in the stacking direction of the lead frame and the conductive clamp for limiting, so as to realize the fixing between the conductive clamp and the lead frame, which is conducive to realizing the fixing of the conductive clamp and the lead frame without increasing the process and changing the structure of the lead frame and the conductive clamp itself, and introducing as few positioning needles as possible for limiting, reducing the influence of the structural error of the structure itself caused by introducing more positioning structures on the positioning precision, and improving the fixing precision of the conductive clamp and the lead frame, and improving the product yield. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 is a schematic diagram of a fixing assembly provided by an exemplary embodiment of the present application for fixing a semiconductor assembly;
[0021] Figure 2 is a top view of a support plate according to an example embodiment of the present application;
[0022] Figure 3 is a top view of a lead frame according to an example embodiment of the present application;
[0023] Figure 4 is a top view of a conductive clip according to an example embodiment of the present application;
[0024] Figure 5 is Figure 1 is a sectional view taken along the section line A-A shown in Fig. 1;
[0025] Figure 6 is a partial sectional view of a fixing assembly according to an example embodiment of the present application;
[0026] Figure 7 is a partial exploded view of a fixing assembly according to an example embodiment of the present application;
[0027] Figure 8 is a sectional view of a first type of positioning cap according to an example embodiment of the present application;
[0028] Figure 9 is a sectional view of a second type of positioning cap according to an example embodiment of the present application. DETAILED DESCRIPTION
[0029] The example embodiments will now be described in detail with reference to the accompanying drawings. If the description of the example embodiments refers to accompanying drawings, then like reference numerals in different drawings designate similar or identical elements. The following detailed description is not intended to represent all embodiments in accordance with the present application. Rather, they are merely example embodiments in accordance with a portion of the application as detailed in the appended claims.
[0030] The terminology used in the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used in the description of the application and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It also will be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.
[0031] The following detailed description will be made with reference to the accompanying drawings. Figures 1 to 9 Some embodiments of the stamping head of the present application will now be described in detail. Features of the various embodiments described below can be combined with each other, as long as there is no conflict.
[0032] Reference will now be made to Figure 1 and where necessary in combination withFigures 2 to 9 As shown, the present application provides a fixing assembly 100 for fixing the lead frame 200 and at least one conductive clip 300 in the intermediate semiconductor assembly 1000 after wire bonding and before high-temperature sintering. The lead frame 200 has lead frame positioning holes 2001 for pre-process on opposite sides 201, 202 in the width direction W1, as shown in Figure 3 The lead frame 200 shown can include a plurality of lead frame unit regions S1. The middle of each lead frame unit region S1 is arranged with a plurality of lead frame sub-units 2002, and each lead frame sub-unit 2002 can correspond to connecting one chip 400. The lead frame positioning holes 2001 for pre-process are located on opposite sides of the region arranged with a plurality of lead frame sub-units 2002 in the width direction W1 of the lead frame 200.
[0033] The conductive clip frame 3000 can include a plurality of conductive clips 300. The conductive clips 300 can be formed by cutting the conductive clip frame 3000. The conductive clip 300 has conductive clip positioning holes 3001 for pre-process on opposite sides 3010, 3020 in the width direction W2, as shown in Figure 4 The conductive clip 300 includes a plurality of conductive clip sub-units 3002, each of which is arranged corresponding to one chip 400 to electrically lead out the corresponding chip 400. The conductive clip positioning holes 3001 for pre-process are specifically located on opposite sides of the plurality of conductive clip sub-units 3002 in the width direction W2.
[0034] In the semiconductor assembly 1000, each lead frame unit region S1 is arranged corresponding to one conductive clip 300. The width direction W2 of the conductive clip 300 is consistent with the width direction W1 of the lead frame 200. In the region corresponding to each conductive clip 300, at least three lead frame positioning holes 2001 for pre-process and at least three conductive clip positioning holes 3001 for pre-process correspond, and the at least three lead frame positioning holes 2001 for pre-process are located on different sides. Exemplarily, Figure 1 The semiconductor assembly 1000 shown shows the region corresponding to one conductive clip 300.
[0035] The fixing assembly 100 includes a support plate 30, a plurality of positioning needles 10, and a plurality of first-type positioning caps 20.
[0036] The support plate 30 has a first side 31 and a second side 32 opposite in the width direction W3 of the support plate 30. The first side 31 and the second side 30 of the support plate 30 are each provided with a support plate positioning hole 301. Each support plate positioning hole 301 corresponds to a conductive clip positioning hole 3001 for pre-process and a lead frame positioning hole 2001 for pre-process.
[0037] The plurality of positioning pins 10 are respectively used to cooperate with one of the support plate positioning holes 301. Each of the conductive clips 300 is fixed by only three positioning pins 10. At least one of the support plate positioning holes 301, in which the three positioning pins 10 for fixing each of the conductive clips 300 cooperate, is located at the first side 31, and at least one is located at the second side 32. Each of the positioning pins 10 can be arranged in a conductive clip positioning hole 3001 and a corresponding lead frame positioning hole 2001, and one end is arranged in a corresponding support plate positioning hole 301.
[0038] The plurality of first type positioning caps 20 are used to be sleeved on the end of the positioning pin 10 away from the support plate positioning hole 301, so as to limit the relative movement of the conductive clip 300 and the lead frame 200 in the stacking direction Z of the conductive clip 300 and the lead frame 200.
[0039] The above-mentioned fixing assembly 100 is provided to include the support plate 30, the plurality of positioning pins 10 and the plurality of first type positioning caps 20. Each of the conductive clips 300 is fixed by only three positioning pins 10 and the lead frame 200, three-point positioning is achieved in the direction perpendicular to the stacking direction of the lead frame 200 and the conductive clip 300, and the first type positioning cap 20 is cooperated to limit the relative movement of the lead frame 200 and the conductive clip 300 in the stacking direction, so as to realize the fixation between the lead frame 200 and the conductive clip 300. This is beneficial to realize the fixation of the conductive clip 300 and the lead frame 200 without increasing the process and changing the structure of the lead frame 200 and the conductive clip 300 itself, and to introduce as few positioning pins 10 as possible to limit the positioning, so as to reduce the influence of the structural error of the structure itself caused by introducing more positioning structures on the positioning precision, and to improve the fixation precision of the conductive clip 300 and the lead frame 200, and to improve the product yield.
[0040] The conductive clip positioning hole 3001 for the preceding process can be a positioning hole used for fixing a conductive clip wafer when the conductive clip 300 is prepared, or a positioning hole used in other preceding process operations before the wire bonding process. Correspondingly, the lead frame positioning hole 2001 for the preceding process is a positioning hole used for fixing a lead frame wafer when the lead frame 200 is prepared, or a positioning hole used in other preceding process operations before the wire bonding process.
[0041] When the positioning assembly 100 is used to fix the semiconductor assembly 1000, the width direction W3 of the support plate 30 is consistent with the width direction W2 of the conductive clip 300 and the width direction W1 of the lead frame 200, which are all consistent with the second direction Y as shown in the figure. Figure 1 The width direction W3 of the support plate 30 is consistent with the width direction W2 of the conductive clip 300 and the width direction W1 of the lead frame 200, which are all consistent with the second direction Y as shown in the figure. Figure 1As shown, the first side 31 and the second side 32 are oppositely arranged in the second direction Y. The opposite sides 201, 202 of the lead frame 200 and the opposite sides of the conductive clip 300 are arranged correspondingly to the first side 31 and the second side 32, respectively. The conductive clip 300 has a plurality of pre-process conductive clip positioning holes 3001 arranged at the corresponding sides in the first direction X. The lead frame 200 has a plurality of pre-process lead frame positioning holes 2001 arranged at the corresponding sides in the first direction X.
[0042] For the convenience of description, the three positioning needles are denoted by the reference numerals 101, 102, and 103, respectively. The positioning needle 101 is inserted into the first side 31. The positioning needles 102 and 103 are inserted into the second side 32. Correspondingly, the positioning needles 101, 102, and 103 are arranged in the first direction X. Figures 2 to 4 The positioning needle 101 can be inserted into one conductive clip positioning hole 30011 and the corresponding lead frame positioning hole 20011, and one end thereof is inserted into the corresponding support plate positioning hole 3011. The positioning needle 102 can be inserted into one conductive clip positioning hole 30012 and the corresponding lead frame positioning hole 20012, and one end thereof is inserted into the corresponding support plate positioning hole 3012. The positioning needle 103 can be inserted into one conductive clip positioning hole 30013 and the corresponding lead frame positioning hole 20013, and one end thereof is inserted into the corresponding support plate positioning hole 3013.
[0043] In some embodiments, the positioning needle 10 is a stainless steel needle made of a graphite material, such as mold steel ASP23. Of course, in other embodiments, the positioning needle 10 can also be other positioning structures with high structural strength.
[0044] In some embodiments, the offset d of the positioning needle 10 in the lead frame positioning hole 2001 and the corresponding conductive clip positioning hole 3001 is less than or equal to 0.01 mm.
[0045] The offset d can be the fitting tolerance between the positioning needle 10 and the corresponding positioning hole.
[0046] The lead frame positioning hole 2001 and the corresponding conductive clip positioning hole 3001 have the same hole diameter shape and size. The cross-sectional shape of the positioning needle 10 matches the hole diameter shape of the lead frame positioning hole 2001 and the corresponding conductive clip positioning hole 3001.
[0047] In some embodiments, the length of the positioning needle 10 is 0.6-0.7 mm.
[0048] In some embodiments, a heat source can be transmitted to the intermediate semiconductor assembly 1000 through the support plate 30 to achieve high-temperature sintering.
[0049] In some embodiments, the support plate 30 is a heat-conducting plate to conduct heat to the intermediate semiconductor component 1000 located thereon to realize high-temperature sintering.
[0050] In some embodiments, the support plate 30 is a heat-conducting plate member with a thermal conductivity coefficient greater than or equal to 150-250 W / (m·K) at 300-400°C.
[0051] In some embodiments, the support plate 30 is a graphite plate made of graphite material.
[0052] In other embodiments, the support plate 30 can be a stainless steel plate made of stainless steel material.
[0053] In other embodiments, the support plate can also be a plate member made of other materials.
[0054] In some embodiments, the support plate 30 has a thickness of 0.10-0.50 mm.
[0055] In some embodiments, the positioning hole 301 has a size of 0.10-0.50 mm in the thickness direction of the support plate 30.
[0056] In some embodiments, the size of the support plate positioning hole 301 in the thickness direction of the support plate 30 is less than or equal to 2 / 3 of the thickness of the support plate 30, so as to control the insertion depth of the positioning needle.
[0057] In some embodiments, the first type of positioning cap 20 is provided with a first cap hole 21 for cooperating with the positioning needle 10.
[0058] In some embodiments, the fixing assembly 100 further comprises a second type of positioning cap 20', which is replaceable with the first type of positioning cap 20 for cooperating with the positioning needle 10, and the second type of positioning cap 20' is provided with a second cap hole 21' for cooperating with the support plate positioning hole 301; wherein the depth h1 of the first cap hole 21 and the depth h2 of the second cap hole 21' are different.
[0059] In some embodiments, the material of the positioning cap 20 is copper material. Both the first type of positioning cap 20 and the second type of positioning cap 20' can be copper material.
[0060] The conductive clip 300 and the lead frame 200 in the semiconductor assembly 1000 have a first distance L1 between two surfaces facing away from each other, the support plate positioning hole 301 has a first depth L2 in the thickness direction of the support plate 30, and the length of the positioning pin 10 is equal to the sum of the first distance L1, the first depth L2 and the depth of the cap hole of the cooperating positioning cap 20, so as to just position the lead frame 200 and the conductive clip 300 in the stacking direction Z.
[0061] Based on the above description, when the conductive clip 300 and the lead frame 200 are fixed by using the fixing assembly 100, the semiconductor assembly 1000 is fixed on the support plate 30, the conductive clip 300 is located on the side of the lead frame 200 facing away from the support plate 30, each positioning pin 10 is inserted into a conductive clip positioning hole 3001 and a corresponding lead frame positioning hole 2001, and one end is inserted into the corresponding positioning hole; wherein at least one of the three support plate positioning holes 301 inserted by the three positioning pins 10 is located on the first side 31, and at least one is located on the second side 32, and each first type of positioning cap is arranged on the other end of a corresponding positioning pin 10. The inventors have confirmed through experiments that the use of the fixing assembly 100 can control the offset of the conductive clip 300 relative to the lead frame 200 to be 50 μm or even lower.
[0062] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the application being indicated by the following claims.
[0063] It should be understood that the application is not limited to the precise construction that has been described above and illustrated in the accompanying drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application. The scope of the application should only be limited by the appended claims.
Claims
1. A fixing assembly for fixing a lead frame and at least one conductive clip in an intermediate semiconductor assembly to be sintered at high temperature, each of the conductive clips having pre-process conductive clip positioning holes located on opposite sides, the lead frame having pre-process lead frame positioning holes located on opposite sides, characterized in that, The fixing component includes: A support plate has a first side and a second side, and both the first side and the second side of the support plate are provided with support plate positioning holes; each support plate positioning hole corresponds to a positioning hole for a conductive clip and a positioning hole for a lead frame in the preceding process. Multiple positioning pins are used to cooperate with one of the positioning holes of the support plate. Each conductive clip is fixed by only three positioning pins. At least one of the positioning holes of the support plate that cooperate with the three positioning pins that fix each conductive clip is located on the first side and at least one is located on the second side. Each positioning pin can pass through a positioning hole of a conductive clip and a corresponding positioning hole of the lead frame, and one end is inserted into the corresponding positioning hole of the support plate. Multiple first-type positioning caps are fitted onto the end of the positioning pin opposite to the positioning hole of the support plate to limit the relative movement of the conductive clip and the lead frame in the stacking direction of the conductive clip and the lead frame.
2. The fixing component as described in claim 1, characterized in that, The positioning pin is a stainless steel pin.
3. The fixing component as described in claim 1, characterized in that, The offset of the positioning pin in the positioning hole of the lead frame and the corresponding positioning hole of the conductive clip is less than or equal to 0.01 mm.
4. The fixing component as claimed in claim 1, characterized in that, The support plate is a heat-conducting plate.
5. The fixing component as claimed in claim 1, characterized in that, The support plate is a graphite plate or a stainless steel plate.
6. The fixing component as claimed in claim 1, characterized in that, The size of the positioning hole in the support plate is less than or equal to 2 / 3 of the thickness of the support plate in the thickness direction.
7. The fixing component as claimed in claim 1, characterized in that, The first type of positioning cap has a first cap hole for engaging with the positioning pin.
8. The fixing component as claimed in claim 7, characterized in that, The fixing component further includes at least one type of second positioning cap, which is interchangeably matched with the positioning pin as the first type of positioning cap. The second type of positioning cap is provided with a second cap hole for matching with the positioning hole of the support plate. The depth of the first cap hole and the depth of the second cap hole are different.
9. The fixing component as claimed in claim 1, characterized in that, The conductive clip includes multiple conductive clip units, each of which corresponds to a chip and is used to electrically lead out the corresponding chip.
10. The fixing component as claimed in any one of claims 1 to 9, characterized in that, The length of the positioning pin is 0.6-0.7 mm; The thickness of the support plate is 0.10-0.50 mm; The size of the positioning hole in the thickness direction of the support plate is 0.10-0.50 mm.