CN221935803U - A clamp - Google Patents

Abstract

The present application provides a clamp for flip-chip welding, comprising: a substrate, the substrate comprising a bearing portion and a limiting portion, the bearing portion being used to place a wafer, and a magnetic plate being embedded in the bearing portion; and a first end of the limiting portion being connected to the bearing portion, and the limiting portion being perpendicular to the surface of the bearing portion; and a cover plate, the cover plate being detachably connected to the cover plate through the second end of the limiting portion and being parallel to the bearing portion, the cover plate having a plurality of openings adapted to the size of the wafer, the material of the cover plate comprising a magnetically permeable material, and the cover plate being able to move along the limiting portion under the magnetic force of the magnetic plate to clamp the wafer. The clamp provided by the present application can clamp the wafer in flip-chip welding to avoid the problem of wafer warping, thereby avoiding the occurrence of cold solder joints during welding.

Description

A clamp

Technical Field

The present application relates to the field of semiconductor manufacturing technology, and in particular to a clamp.

Background Art

Referring to Figures 1 and 2, as the size of the wafer 10 in flip-chip (Chip on Wafer, COW) becomes larger and larger, especially when the package size (i.e., the size of the wafer 10) exceeds 55x55mm, the wafer 10 will have an edge warping problem. This makes it impossible for the metal ball 30 (Bump) used for welding between the wafer 10 and the chip 20 to contact the wire (Pad) at the center of the wafer 10 during high-temperature reflow soldering, resulting in cold solder joints.

The maximum package size of advanced packaging products has reached 102x102cm and is still increasing. At the same time, the number of layers of Ajinomoto enhancement film (ABF) on the surface of large-size wafers is usually more than ten, further aggravating the warping problem of the wafer.

Therefore, a clamp is needed to clamp the wafer during flip-chip bonding to avoid the warping problem of the wafer.

Utility Model Content

The purpose of this application is to provide a clamp that can clamp the wafer during flip-chip welding to avoid the warping problem of the wafer.

An embodiment of the present application provides a clamp for flip-chip welding, comprising: a substrate, the substrate comprising a bearing portion and a limiting portion, the bearing portion being used to place a wafer, and a magnetic plate being embedded in the bearing portion; and a first end of the limiting portion being connected to the bearing portion, and the limiting portion being perpendicular to the surface of the bearing portion; and a cover plate, the cover plate being detachably connected to the cover plate through the second end of the limiting portion and being parallel to the bearing portion, the cover plate having a plurality of openings adapted to the size of the wafer, the material of the cover plate comprising a magnetically conductive material, and the cover plate being able to move along the limiting portion under the action of the magnetic force of the magnetic plate to clamp the wafer.

In some embodiments, the cover plate is provided with a first through hole adapted to the limiting portion.

In some embodiments, the magnetic induction intensity of the magnetic plate is greater than or equal to 0.7-1.0 Tesla.

In some embodiments, the magnetic plate is provided with a second through hole penetrating the magnetic plate and matching the opening, and an area of the second through hole is less than or equal to an area of the opening.

In some embodiments, the material of the bearing portion includes at least one of stainless steel and stainless iron.

In some embodiments, the surface of the carrier portion includes a nickel coating.

In some embodiments, there are multiple limiting portions, and the limiting portions are distributed in an array.

In some embodiments, the material of the cover plate includes stainless steel.

In some embodiments, the opening has a square cross-section.

In some embodiments, the number of the openings is multiple, and the multiple openings are distributed in a matrix.

The beneficial effects of the clamp provided by the embodiment of the present application include but are not limited to the following:

The clamp provided in the embodiment of the present application includes a substrate and a cover plate, wherein a magnetic plate is embedded in the substrate, and the cover plate is a magnetically conductive material. The cover plate and the substrate can clamp the edge of the wafer under the action of magnetic force to prevent the wafer from warping, thereby preventing cold solder joints from occurring during flip-chip soldering between the wafer and the chip.

The sizes of the substrate and the cover plate and the opening of the cover plate can be adapted according to the size and number of wafers to achieve welding of multiple wafers and chips.

BRIEF DESCRIPTION OF THE DRAWINGS

The following figures describe in detail the exemplary embodiments disclosed in this application. The same reference numerals represent similar structures in several views of the drawings. Those skilled in the art will understand that these embodiments are non-limiting, exemplary embodiments, and the drawings are only for the purpose of illustration and description, and are not intended to limit the scope of this application. Other embodiments may also accomplish the inventive intent in this application. It should be understood that the drawings are not drawn to scale.

in:

FIG1 is a schematic diagram of the structure of flip-chip welding;

FIG2 is an enlarged view of the boxed area in FIG1 ;

FIG3 is a schematic structural diagram of a clamp according to some embodiments of the present application;

FIG4 is a schematic structural diagram of a substrate according to some embodiments of the present application;

FIG5 is a schematic structural diagram of a cover plate according to some embodiments of the present application;

FIG6 is a schematic structural diagram of a clamp according to other embodiments of the present application;

FIG7 is a schematic structural diagram of a substrate according to some other embodiments of the present application; and

FIG8 is a schematic structural diagram of a cover plate according to other embodiments of the present application.

DETAILED DESCRIPTION

The following description provides specific application scenarios and requirements of the present application, with the purpose of enabling those skilled in the art to make and use the content in the present application. It will be apparent to those skilled in the art that various local modifications to the disclosed embodiments are apparent, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present application. Therefore, the present application is not limited to the embodiments shown, but to the widest scope consistent with the claims.

The present application provides a clamp for flip-chip welding, comprising: a substrate, the substrate comprising a bearing portion and a limiting portion, the bearing portion being used to place a wafer, and a magnetic plate being embedded in the bearing portion; and a first end of the limiting portion being connected to the bearing portion, and the limiting portion being perpendicular to the surface of the bearing portion; and a cover plate, the cover plate being detachably connected to the cover plate through the second end of the limiting portion and being parallel to the bearing portion, the cover plate having a plurality of openings adapted to the size of the wafer, the material of the cover plate comprising a magnetically conductive material, and the cover plate being able to move along the limiting portion under the magnetic force of the magnetic plate to clamp the wafer.

The clamp provided in the present application sets the wafer between the base and the cover plate, and clamps the edge of the wafer by magnetic force to prevent the wafer from warping and affecting the occurrence of cold solder joints between the wafer and the chip.

The clamp provided in the present application will be described in detail below in conjunction with the embodiments and drawings.

3 to 8 , the present application provides a clamp, including a substrate 100 and a cover plate 200, wherein the substrate 100 and the cover plate 200 can clamp a wafer 10 disposed between the substrate 100 and the cover plate 200 under the action of magnetic force. The X direction is defined as the length direction, the Y direction is defined as the width direction, and the Z direction is defined as the thickness direction.

In some embodiments, the substrate 100 includes a carrying portion 101 , and the carrying portion 101 is used to place the wafer 10 .

In some embodiments, the material of the carrier part 101 is at least one of stainless steel and stainless iron, and the material of the carrier part 101 can withstand the high temperature in flip-chip bonding.

In some embodiments, the surface of the carrier 101 includes a nickel coating to prevent the surface of the carrier 101 from being oxidized during reverse welding.

In some embodiments, the carrier 101 is in any shape of a cuboid, a cube, a cylinder or an irregular body. Preferably, the carrier 101 is a cuboid. The size of the carrier 101 is adapted to the size and quantity of the wafer 10. In some embodiments, the length of the carrier 101 is greater than or equal to 60 mm; the width of the carrier 101 is greater than or equal to 60 mm; and the thickness of the carrier 101 is 5 mm to 10 mm. In some embodiments, the length of the carrier 101 is 60 mm, 80 mm, 160 mm or 320 mm. In some embodiments, the width of the carrier 101 is 60 mm, 75 mm, 80 mm or 150 mm. In some embodiments, the thickness of the carrier 101 is 5 mm to 10 mm. In some embodiments, the length of the carrier 101 is 320 mm; the width is 150 mm.

In some embodiments, a magnetic plate 102 is embedded in the carrier 101 , and the magnetic plate 102 can move the cover plate 200 toward the substrate 100 through magnetic force, thereby clamping the wafer 10 disposed between the cover plate 200 and the substrate 100 .

In some embodiments, the magnetic induction intensity of the magnetic plate 102 is greater than or equal to 0.7-1.0 Tesla, so as to provide sufficient magnetic force to clamp the wafer 10 .

In some embodiments, the material of the magnetic plate 102 includes AlNiCo magnets. The AlNiCo magnets have good high temperature resistance and can maintain magnetism during flip-chip bonding.

In some embodiments, the magnetic plate 102 is in any shape of a cuboid, a cube, a cylinder or an irregular body. In some embodiments, the magnetic plate 102 is a cuboid. The size of the magnetic plate 102 is adapted to the size and quantity of the wafer 10. In some embodiments, the length of the magnetic plate 102 is greater than or equal to 55 mm; the width of the magnetic plate 102 is greater than or equal to 55 mm; and the thickness of the magnetic plate 102 is 5 to 10 mm. In some embodiments, the length of the magnetic plate 102 is 55 mm, 75 mm, 150 mm or 300 mm. In some embodiments, the length of the magnetic plate 102 is 55 mm, 60 mm, 75 mm or 140 mm. In some embodiments, the length of the magnetic plate 102 is 55 mm and the width is 55 mm, which is the same as the length and width of the wafer 10.

In some embodiments, the distance between the top surface of the magnetic plate 102 and the top surface of the carrying portion 101 is 3-10 mm.

In some embodiments, the magnetic plate 102 is provided with a second through hole 102 a penetrating the magnetic plate 102 , and the cross-sectional area of the second through hole 102 a is smaller than the cross-sectional area of the wafer 10 , so that the magnetic plate 102 exists below the edge area of the wafer 10 .

The number of the second through holes 102a is adapted to the number of the wafer 10. In some embodiments, referring to FIG4, the number of the second through holes 102a is one. In some embodiments, the number of the second through holes 102a is multiple, and the multiple second through holes 102a are distributed in an array. In some embodiments, the number of the second through holes 102a is 2, 4, 6 or 8. In some embodiments, referring to FIG7, the number of the second through holes 102a is 8.

In some embodiments, the cross section of the second through hole 102a is circular, rectangular or square. In some embodiments, the cross section of the second through hole 102a is square. In some embodiments, the length of the second through hole 102a is 32 mm, 33 mm, 66 mm or 99 mm. In some embodiments, the width of the second through hole 102a is 32 mm, 33 mm, 66 mm or 99 mm. In some embodiments, the length of the second through hole 102a is 33 mm, and the width of the second through hole 102a is 33 mm.

The substrate 100 provided in the embodiment of the present application further includes a limiting portion 103, a first end of which is connected to the carrying portion 101, and the limiting portion 103 is perpendicular to the surface of the carrying portion 101. The limiting portion 103 enables the cover plate 200 to be arranged parallel to the carrying portion 101 and cover the carrying portion 101, thereby clamping the wafer 10 disposed between the carrying portion 101 and the cover plate 200.

The number of the limiting parts 103 is not limited, and the cover plate 200 can be limited. In some embodiments, the number of the limiting parts 103 is one. In some embodiments, the number of the limiting parts 103 is multiple, and the multiple limiting parts 103 are distributed in an array. In some embodiments, the spacing between adjacent limiting parts 103 is 50 mm, 55.3 mm, 60 mm or 63 mm. In some embodiments, the spacing between adjacent limiting parts 103 is 55.3 mm.

The shape of the limiting portion 103 is not limited, and the cover plate 200 can be limited. In some embodiments, the limiting portion 103 can be a cylinder, a cuboid, a cube, or an irregular shape. In some embodiments, the limiting portion 103 is a cylinder, the diameter of the limiting portion 103 is 2 to 5 mm, and the width of the limiting portion 103 is 2 to 5 mm.

In some embodiments, the limiting portion 103 and the carrying portion 101 are integrally formed.

The cover plate 200 provided in the embodiment of the present application is detachably connected to the cover plate 200 through the second end of the limiting portion 103 and is parallel to the supporting portion 101. The material of the cover plate 200 includes magnetically conductive material. The cover plate 200 can move along the limiting portion 103 under the magnetic force of the magnetic plate 102 to clamp the wafer 10.

In some embodiments, the material of the cover plate 200 includes stainless steel. The stainless steel has good magnetic conductivity, and can enable the cover plate 200 to move along the limiting portion 103 under the magnetic force of the magnetic plate 102 .

In some embodiments, the cover plate 200 has a plurality of openings 201 that are adapted to the size of the wafer 10. The shape of the opening 201 is not limited, as long as the cover plate 200 covers the edge area of the wafer 10. In some embodiments, the cross-section of the opening 201 is circular, rectangular, or square. In some embodiments, the cross-sectional area of the opening 201 is square.

In some embodiments, the cross-sectional area of the opening 201 is greater than or equal to the cross-sectional area of the chip 20, so that the chip 20 can contact the wafer 10. In some embodiments, the cross-sectional area of the opening 201 is greater than or equal to the cross-sectional area of the second through hole 102a, so that the corresponding magnetic plate 102 is disposed below the area of the cover plate 200 in contact with the wafer 10, so as to enhance the magnetic force between the cover plate 200 and the magnetic plate 102, strengthen the clamping of the edge area of the wafer 10, and prevent the wafer 10 from warping.

In some embodiments, the length of the opening 201 is 34 mm, 35 mm, 70 mm or 100 mm. In some embodiments, the length of the opening 201 is 34 mm, 35 mm, 70 mm or 100 mm.

The number of the openings 201 is adapted to the number of the wafers 10. In some embodiments, referring to FIG5 , the number of the openings 201 is one. In some embodiments, the number of the openings 201 is multiple, and the multiple openings 201 are distributed in a matrix to achieve welding of multiple wafers 10 at the same time. In some embodiments, the number of the openings 201 is 2, 4 or 8. In some embodiments, referring to FIG8 , the number of the second through holes 102a is 8.

In some embodiments, the cover plate 200 is provided with a first through hole 202 adapted to the limiting portion 103. By inserting the limiting portion 103 into the first through hole 202, the cover plate 200 can be parallel to the supporting portion 101 and covered on the supporting portion 101 to clamp the wafer 10. In some embodiments, the cross-section of the first through hole 202 is circular, rectangular, square or irregular. In some embodiments, the inner diameter of the first through hole 202 is greater than or equal to the outer diameter of the limiting portion 103.

In some embodiments, the process of flip-chip welding the wafer 10 and the chip 20 using the fixture provided in the embodiment of the present application is as follows: 8 wafers 10 of 55x55 mm are placed in the corresponding area on the surface of the carrier 101, the first through hole 202 on the cover plate 200 is aligned with the limit part 103 on the substrate 100, and the cover plate 200 moves downward along the limit part 103 under the action of magnetism and gravity, and clamps the wafer 10 together with the carrier 101. 8 chips 20 of 34x34 mm are placed correspondingly on the surface of the wafer 10 exposed by the opening 201. The fixture is placed on the operating table, and the wafer 10 and the chip 20 are subjected to high-temperature reflow soldering. After the soldering is completed, the cover plate 200 is removed from the substrate 100, and the wafer 10 and the chip 20 that have been soldered together are removed.

The beneficial effects of the clamp provided by the embodiment of the present application include but are not limited to the following:

The clamp provided in the embodiment of the present application includes a substrate and a cover plate, wherein a magnetic plate is embedded in the substrate, and the cover plate is a magnetically conductive material. The cover plate and the substrate can clamp the edge of the wafer under the action of magnetic force to prevent the wafer from warping, thereby preventing cold solder joints from occurring during flip-chip soldering between the wafer and the chip.

The sizes of the substrate and the cover plate and the opening of the cover plate can be adapted according to the size and number of wafers to achieve welding of multiple wafers and chips.

It should be noted that different embodiments may produce different beneficial effects. In different embodiments, the beneficial effects that may be produced may be any one or a combination of the above, or any other beneficial effects that may be obtained.

The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of this specification. Although not explicitly stated here, those skilled in the art may make various modifications, improvements and corrections to this application. Such modifications, improvements and corrections are suggested in this specification, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of this application.

It should be noted that in the description of this application, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", and "fix" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a rotating connection or a sliding connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood in combination with specific circumstances.

In addition, when terms such as "first", "second", and "third" are used in the specification of this application to describe various features, these terms are only used to distinguish these features and cannot be understood as indicating or implying the relationship between the features, the relative importance, or implicitly indicating the number of features indicated.

In addition, the present specification describes exemplary embodiments by reference to idealized exemplary cross-sectional views and/or plan views and/or stereograms. Therefore, differences from the illustrated shapes due to, for example, manufacturing techniques and/or tolerances are foreseeable. Therefore, the exemplary embodiments should not be interpreted as being limited to the shapes of the regions shown herein, but should include deviations in shapes caused by, for example, manufacturing. Therefore, the regions shown in the figures are schematic in nature, and their shapes are not intended to illustrate the actual shapes of the regions of the device nor to limit the scope of the exemplary embodiments.

At the same time, the present application uses specific words to describe the embodiments of this specification. For example, "one embodiment", "an embodiment", and/or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in the present application does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

Finally, it should be understood that the embodiments described in this application are only used to illustrate the principles of the embodiments of the present application. Other variations may also fall within the scope of the present application. Therefore, as an example and not a limitation, the alternative configurations of the embodiments of the present application may be considered to be consistent with the teachings of the present application. Accordingly, the embodiments of the present application are not limited to the embodiments explicitly introduced and described in the present application.

Claims (10)

1. A fixture for flip-chip bonding, comprising:

The substrate comprises a bearing part and a limiting part, wherein the bearing part is used for placing a wafer, and a magnetic plate is buried in the bearing part; the first end of the limiting part is connected to the bearing part, and the limiting part is vertical to the surface of the bearing part; and

The cover plate is detachably connected with the cover plate through the second end of the limiting part and is parallel to the bearing part, a plurality of openings matched with the size of the wafer are formed in the cover plate, the material of the cover plate comprises a magnetic conduction material, and the cover plate can move along the limiting part under the action of magnetic force of the magnetic plate so as to clamp the wafer.

2. The clamp according to claim 1, wherein the cover plate is provided with a first through hole adapted to the limit portion.

3. The jig according to claim 1, wherein the magnetic induction intensity of the magnetic plate is 0.7 to 1.0 dtex or more.

4. The jig according to claim 1, wherein the magnetic plate is provided with a second through hole penetrating the magnetic plate and matching the opening, and an area of the second through hole is equal to or smaller than an area of the opening.

5. The clamp of claim 1, wherein the material of the load bearing portion comprises at least one of stainless steel and stainless iron.

6. The clip of claim 5 wherein the surface of the carrier portion comprises a nickel coating.

7. The clamp of claim 1, wherein the number of limit portions is a plurality, and the plurality of limit portions are distributed in an array.

8. The fixture of claim 1, wherein the material of the cover plate comprises stainless iron.

9. The clamp of claim 1, wherein the opening is square in cross-section.

10. The fixture of claim 1, wherein the number of openings is a plurality, the plurality of openings being distributed in a matrix.