Mold for manufacturing semiconductor structure and preparation method thereof

Abstract

The invention provides a mold for manufacturing a semiconductor structure and a preparation method thereof. The mold is used for processing a semiconductor intermediate structure to obtain a semiconductor structure. The semiconductor intermediate structure comprises a substrate, a lead frame, a chip and a plastic package layer, and the pins are exposed out of the plastic package layer. The mold comprises a first sub-mold and a second sub-mold. The first sub-mold comprises a first mounting seat and a first abutting part mounted on the first mounting seat, the first abutting part comprises a first abutting surface, and the first abutting surface is concave towards the direction of the first mounting seat; the second sub-mold comprises a second mounting seat and a second abutting part mounted on the second mounting seat, the second abutting part comprises a second abutting surface, and the second abutting surface protrudes in the direction away from the second mounting seat; the first abutting surface and the second abutting surface are used for abutting against one of two opposite surfaces of each pin located on the same side of the plastic packaging layer when the semiconductor intermediate structure is placed in a mold.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a mold for manufacturing a semiconductor structure and a preparation method thereof. Background Art

[0002] The preparation process of some semiconductor devices, such as power modules, is as follows: first, a lead frame is mounted on a DBC (Directed Bonding Copper) substrate, and then the chip is mounted on the base island of the lead frame, and then a plastic layer is formed to encapsulate the chip, the DBC substrate and part of the lead frame structure, and the surface of the DBC substrate away from the chip is exposed to the plastic layer, and the pins of the lead frame are exposed to the side of the plastic layer; then the obtained semiconductor structure is fixed on the lower mold of the mold assembly, and the upper mold and the lower mold of the mold assembly are molded together, and the two opposite surfaces of the ends of the pins adjacent to the plastic layer are respectively abutted against the abutment surfaces of the upper mold and the abutment surfaces of the lower mold to fix the semiconductor structure; then the tool of the mold assembly performs the cutting and pin forming processes on the semiconductor structure.

[0003] In the process of forming the plastic layer, due to the large difference in thermal expansion coefficients between the material of the plastic layer and the material of the DBC substrate, the plastic layer will be warped, resulting in a height difference between adjacent pins on the same side of the plastic layer. The abutting surfaces of the upper mold and the lower mold are both flat. In the process of closing the upper mold and the lower mold, the abutting surface of the upper mold first contacts the pin with a higher position and applies force to the pin that contacts first, which will cause the pin to deform unexpectedly or even break. Summary of the invention

[0004] The embodiments of the present application provide a mold for manufacturing a semiconductor structure and a preparation method thereof.

[0005] According to a first aspect of an embodiment of the present application, a mold for manufacturing a semiconductor structure is provided, wherein the mold is used to process a semiconductor intermediate structure to obtain a semiconductor structure; the semiconductor intermediate structure comprises a substrate, a lead frame, a chip and a plastic encapsulation layer, the lead frame and the chip are located on the substrate, the lead frame comprises a plurality of pins, the plastic encapsulation layer encapsulates the substrate, the chip and the lead frame, and the pins are exposed from the plastic encapsulation layer; the mold for manufacturing a semiconductor structure comprises a first sub-mold and a second sub-mold;

[0006] The first sub-mold includes a first mounting seat and a first abutting portion mounted on the first mounting seat, the first abutting portion includes a first abutting surface, and the first abutting surface is concave toward the direction of the first mounting seat;

[0007] The second sub-mold includes a second mounting seat and a second abutting portion mounted on the second mounting seat, the second abutting portion includes a second abutting surface, and the second abutting surface protrudes in a direction away from the second mounting seat; the first abutting surface and the second abutting surface are used to abut against one of the two opposite surfaces of each of the pins located on the same side of the plastic packaging layer when the semiconductor intermediate structure is placed in the mold.

[0008] In one embodiment, the first abutting surface and the second abutting surface are both arched.

[0009] In one embodiment, in the length direction of the first abutting surface, the first abutting surface is provided with a plurality of first planes arranged at intervals, and the distances between two adjacent first planes and the first mounting seat are different; in the length direction of the second abutting surface, the second abutting surface is provided with a plurality of second planes arranged at intervals, and the distances between two adjacent second planes and the second mounting seat are different.

[0010] In one embodiment, the first abutting surface has a first symmetric plane, the first abutting surface includes two opposite first side edges, and the two first side edges are in the same plane, the first symmetric plane is perpendicular to the plane where the two first side edges are located and parallel to the first side edges, and the first abutting surface is symmetrical about the first symmetric plane;

[0011] The second abutting surface has a second symmetric plane, the second abutting surface includes two opposite second side edges, and the two second side edges are in the same plane, the second symmetric plane is perpendicular to the plane where the two second side edges are located and parallel to the second side edges, and the second abutting surface is symmetrical about the second symmetric plane.

[0012] In one embodiment, the first sub-mold further comprises a tool, the tool is mounted on the first mounting seat, and the blade of the tool and the first abutment surface are located on the same side of the first mounting seat; the blade of the tool is concave inwardly toward the direction of the first mounting seat.

[0013] In one embodiment, the second sub-mold also includes a supporting portion, which is mounted on the second mounting seat, and the supporting portion includes a supporting surface, and the supporting surface and the second abutting surface are located on the same side of the second mounting seat; the supporting surface is used to abut against the pin, and the area where the pin abuts against the supporting surface is located on the side of the area abutting against the second abutting surface away from the plastic packaging layer; the supporting surface protrudes in a direction away from the second mounting seat.

[0014] According to a second aspect of an embodiment of the present application, there is provided a method for preparing a mold for manufacturing a semiconductor structure, wherein the mold is used to process a semiconductor intermediate structure to obtain a semiconductor structure; the semiconductor intermediate structure comprises a substrate, a lead frame, a chip and a plastic layer, the lead frame and the chip are located on the substrate, the lead frame comprises a plurality of pins, the plastic layer encapsulates the substrate, the chip and the lead frame, and the pins are exposed from the plastic layer; the plastic layer is warped toward a surface away from the substrate where the plastic layer is exposed; the mold comprises a first sub-mold and a second sub-mold; the first sub-mold comprises a first mounting seat and a second mounting seat mounted on the first sub-mold. A first abutting portion of a mounting seat, the first abutting portion includes a first abutting surface, the second sub-mold includes a second mounting seat and a second abutting portion mounted on the second mounting seat, the second abutting portion includes a second abutting surface; the first abutting surface and the second abutting surface are used to abut against one of two opposite surfaces of the pin when the semiconductor intermediate structure is placed in the mold; the plastic encapsulation layer has a warped surface, and the cross-section of the warped surface in a direction parallel to the length direction of the plastic encapsulation layer is an arc; the arc includes a first endpoint and a second endpoint opposite to each other, and the first endpoint and the second endpoint are on the same straight line; the preparation method includes:

[0015] Providing a plurality of semiconductor intermediate structures, and determining distance data corresponding to a plurality of points in the arc for each semiconductor intermediate structure, wherein the distance data corresponding to each point includes a first distance between the point and the straight line, and a second distance between the point and a target point on the straight line in a direction parallel to the straight line;

[0016] Determine, based on the distance data of the plurality of semiconductor intermediate structures, data information representing a depth of the first abutting surface being concave in a direction toward the first mounting seat and a height of the second abutting surface being convex in a direction away from the second mounting seat;

[0017] The shape of the first abutting surface and the shape of the second abutting surface are determined according to the data information, and the first abutting surface and the second abutting surface are prepared.

[0018] In one embodiment, the data information includes an equation of the first distance with respect to the second distance; and the data information characterizing the depth of the first abutting surface being concave in a direction toward the first mounting seat and the height of the second abutting surface being protruded in a direction away from the second mounting seat is determined according to the distance data of the plurality of semiconductor intermediate structures, including:

[0019] fitting an equation of the first distance with respect to the second distance according to the distance data of the plurality of semiconductor structures;

[0020] The determining the shape of the first abutting surface and the shape of the second abutting surface according to the data information includes:

[0021] The shapes of the first abutment surface and the second abutment surface are determined according to the equation, so that the shape of the cross section of the first abutment surface in a direction parallel to its length direction matches the equation, and the shape of the cross section of the second abutment surface in a direction parallel to its length direction matches the equation.

[0022] In one embodiment, the first abutting surface and the second abutting surface prepared according to the data information are both arched; after preparing the first abutting surface and the second abutting surface according to the data information, the preparation method further includes:

[0023] A plurality of first planes arranged at intervals are formed on the first abutting surface, and the plurality of first planes are arranged in the length direction of the first abutting surface; a plurality of second planes arranged at intervals are formed on the second abutting surface, and the plurality of second planes are arranged in the length direction of the second abutting surface.

[0024] In one embodiment, the first sub-mold further comprises a cutting tool, the cutting tool is mounted on the first mounting seat, and the cutting edge of the cutting tool and the first abutting surface are located on the same side of the first mounting seat; the data information further represents the depth of the cutting edge concave in the direction toward the first mounting seat; the preparation method further comprises: determining the shape of the cutting edge according to the data information, and preparing the cutting edge;

[0025] and / or,

[0026] The second sub-mold also includes a supporting portion, which is mounted on the second mounting seat, and the supporting portion includes a supporting surface, and the supporting surface and the second abutting surface are located on the same side of the second mounting seat; the data information also represents the height of the supporting surface protruding in the direction away from the second mounting seat; the preparation method also includes: determining the shape of the supporting surface according to the data information, and preparing the supporting surface.

[0027] The main technical effects achieved by the embodiments of the present application are:

[0028] The semiconductor structure provided in the embodiment of the present application is a mold for manufacturing a semiconductor structure and a preparation method thereof. After the semiconductor intermediate structure is placed on the mold and the first sub-mold is molded together with the second sub-mold, one surface of the pin abuts against the second abutting surface of the second abutting portion. After the first sub-mold is molded together with the second sub-mold, the surface of the pin opposite to the second abutting surface abuts against the first abutting surface of the first abutting portion. Since the first abutting surface of the first abutting portion is concave inwardly toward the direction of the first mounting seat, and the second abutting surface of the second abutting portion is convex in the direction away from the second mounting seat, when the two ends of the plastic encapsulation layer are warped in the direction away from the substrate so that the distances between the pins on the same side of the plastic encapsulation layer and the substrate are different, the first abutting surface and the second abutting surface can be better fitted with each pin, which helps to reduce the gap between the pin and the first abutting surface and the second abutting surface, can improve the problems of unexpected deformation and breakage of the pin, and improve the yield of the semiconductor structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a bottom view of a semiconductor intermediate structure provided by an exemplary embodiment of the present application;

[0030] Figure 2 is a side view of a semiconductor intermediate structure provided by an exemplary embodiment of the present application;

[0031] Figure 3 is a schematic diagram of a cross section of an inner concave surface of a plastic package body provided by an exemplary embodiment of the present application;

[0032] Figure 4 is a side view of a mold provided by an exemplary embodiment of the present application;

[0033] Figure 5 is a side view of a first abutting surface and a second abutting surface provided by an exemplary embodiment of the present application;

[0034] Figure 6 is a side view of a first abutting surface and a second abutting surface provided by another exemplary embodiment of the present application;

[0035] Figure 7 It is a flow chart of a method for preparing a mold for manufacturing a semiconductor structure provided by another exemplary embodiment of the present application. Specific embodiments

[0036] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0037] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0038] It should be understood that although the terms first, second, third, etc. may be used in the present application to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0039] Some embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0040] An embodiment of the present application provides a mold for manufacturing a semiconductor structure, where the mold is used to process a semiconductor intermediate structure to obtain a semiconductor structure.

[0041] Semiconductor intermediate structures are structures formed during the process of preparing semiconductor structures. Figure 1 As shown, the semiconductor intermediate structure includes a substrate 10, a lead frame 20, a chip (not shown) and a plastic layer 30. The lead frame 20 and the chip are located on the substrate 10. The lead frame 20 includes a plurality of pins 21, and the plastic layer 30 encapsulates the substrate 10, the chip and the lead frame 20, and the pins 21 are exposed from the plastic layer 30. The plurality of pins 21 can be exposed from opposite sides of the plastic layer 30, and each of the two sides of the plastic layer is provided with a plurality of pins 21. The pins 21 are straight structures. The substrate 10 can be a DBC substrate.

[0042] The lead frame 20 also includes a base island, a frame body, a connecting rod and a connecting rib. The base island, the connecting rod, the connecting rib and the pin 21 are all located in the space enclosed by the frame body. The chip can be mounted on the base island. Multiple pins located on the same side of the plastic encapsulation layer 30 are connected by connecting rods. The connecting ribs are exposed from the plastic encapsulation body and are respectively connected to the frame body and the base island.

[0043] In getting Figure 1After the semiconductor intermediate structure shown in the figure is obtained, the mold provided in the embodiment of the present application can be used to process the semiconductor intermediate structure, remove the connecting rod, cut off the connecting rib, and bend the pin 21 to obtain a semiconductor structure. The final semiconductor structure includes a substrate 10, a base island, pins, a chip and a plastic encapsulation layer 30, and the pins can be in a broken line shape.

[0044] In preparation Figure 1 In the process of manufacturing the semiconductor structure shown in the figure, the lead frame 20 and the chip are first mounted on the substrate 10, and then the plastic encapsulation layer 30 is formed. Since the thermal expansion coefficient of the material of the plastic encapsulation layer 30 is greatly different from that of the material of the substrate 10, the opposite ends of the formed plastic encapsulation layer 30 in the length direction will bend away from the substrate 10. Figure 2 As shown, the two opposite surfaces of the plastic encapsulation layer 30 are warped surfaces, both of which are arched; and among the multiple pins 21 located on the same side of the plastic encapsulation layer 30, the distance between the pin 21 and the substrate gradually decreases from the pin 21 located at the edge to the pin 21 located in the middle area. The warped surface includes an inner concave surface 31 and an outer convex surface 32, and the inner concave surface 31 and the outer convex surface 32 are opposite to each other, and the shapes of the two can be basically the same. The distance between the center of each pin 21 and the inner concave surface 31 is roughly the same, and the distance between the center of each pin 21 and the outer convex surface 32 is roughly the same. Figure 3 As shown, the cross section of the warped surface in the direction parallel to the length direction of the plastic encapsulation layer 30 is an arc. That is, the cross section of the inner concave surface 31 in the direction parallel to the length direction of the plastic encapsulation layer 30 is an arc, and the cross section of the outer convex surface 32 in the direction parallel to the length direction of the plastic encapsulation layer 30 is an arc, and the cross-sectional shape of the inner concave surface 31 and the cross-sectional shape of the outer convex surface 32 may be substantially the same.

[0045] like Figure 4 As shown, the mold for manufacturing a semiconductor structure provided in the embodiment of the present application includes a first sub-mold 40 and a second sub-mold 50 .

[0046] The first sub-mold 40 includes a first mounting seat 41 and a first abutting portion 42 mounted on the first mounting seat 41, the first abutting portion 42 includes a first abutting surface 421, and the first abutting surface 421 is concave toward the first mounting seat 41. The second sub-mold 50 includes a second mounting seat 51 and a second abutting portion 52 mounted on the second mounting seat 51, the second abutting portion 52 includes a second abutting surface 521, and the second abutting surface 521 protrudes in a direction away from the second mounting seat 51; the first abutting surface 421 and the second abutting surface 521 are used to abut against one of the two opposite surfaces of each of the pins 21 located on the same side of the plastic encapsulation layer 40 when the semiconductor intermediate structure is placed in the mold.

[0047] The mold for manufacturing a semiconductor structure provided in an embodiment of the present application has the following steps: after the semiconductor intermediate structure is placed on the mold and the first sub-mold is molded together with the second sub-mold, one surface of the pin is molded together with the second abutting surface of the second abutting portion; after the first sub-mold is molded together with the second sub-mold, the surface of the pin opposite to the second abutting surface is molded together with the first abutting surface of the first abutting portion; since the first abutting surface of the first abutting portion is concave inwardly toward the direction of the first mounting seat, and the second abutting surface of the second abutting portion is convex in the direction away from the second mounting seat, when the two ends of the plastic encapsulation layer are warped in the direction away from the substrate so that the distances between the pins on the same side of the plastic encapsulation layer and the substrate are different, the first abutting surface and the second abutting surface can be better fitted with each pin, which helps to reduce the gap between the pin and the first abutting surface and the second abutting surface, can improve the problems of unexpected deformation and breakage of the pin, and improve the yield of the semiconductor structure.

[0048] In one embodiment, Figure 4 As shown, after the first sub-mold 40 and the second sub-mold 50 are molded together, the first abutting surface 421 and the second abutting surface 521 are opposite to each other, and the first abutting surface 421 and the second abutting surface 521 respectively abut against the area of ​​the lead 21 close to the plastic packaging layer 30.

[0049] In one embodiment, Figure 4 As shown, the first sub-mold 40 is an upper mold, and the second sub-mold 50 is a lower mold. When using the mold provided in the embodiment of the present application, the semiconductor intermediate structure is first placed on the second sub-mold 50, the substrate of the semiconductor intermediate structure is located on the side of the inner concave surface 31 of the plastic encapsulation layer 30 away from the second mounting seat 51, and the pin 21 abuts against the second abutting surface 521; then the first sub-mold 40 and the second sub-mold 50 are molded together, so that the first abutting surface 421 abuts against the surface of the pin 21 away from the second abutting surface 521.

[0050] In one embodiment, Figure 5As shown, the first abutting surface 421 and the second abutting surface 521 are both arched. The surface of the pin 21 facing the first abutting surface 421 contacts a portion of the first abutting surface 421 , and the surface of the pin 21 facing the second abutting surface 521 contacts a portion of the second abutting surface 521 . The first abutting surface 421 and the second abutting surface 521 are designed to be arched, and the shapes of the first abutting surface 421 and the second abutting surface 521 are close to the surface shape of the plastic packaging layer 30, and the height of the pin 21 changes with the warping of the plastic packaging layer 30. The distance between the center of each pin 21 and the inner concave surface 31 of the plastic packaging layer 30 is roughly the same, and the distance between the center of each pin 21 and the outer convex surface 32 of the plastic packaging layer 30 is roughly the same, and the width of the pin 21 is generally small, so that the surface of the pin 21 facing the first abutting surface 421 can be better fitted with the first abutting surface 421, and the surface of the pin 21 facing the second abutting surface 521 can be better fitted with the second abutting surface 521, effectively reducing the gap between the pin 21 and the first abutting surface 421 and the second abutting surface 521.

[0051] In one embodiment, the cross-section of the first abutting surface 421 perpendicular to its length direction is an arc, which is roughly parabolic, and the cross-section of the second abutting surface 521 perpendicular to its length direction is an arc, which is roughly parabolic; and the cross-section of the first abutting surface 421 and the cross-section of the second abutting surface 521 may be roughly the same as the cross-sectional shape of the inner concave surface of the plastic encapsulation layer 30.

[0052] In another embodiment, if Figure 6 As shown, in the length direction of the first abutting surface 421, the first abutting surface 421 is provided with a plurality of first planes 422 arranged at intervals, and the distances between two adjacent first planes 422 and the first mounting seat 41 are different; in the length direction of the second abutting surface 521, the second abutting surface 521 is provided with a plurality of second planes 522 arranged at intervals, and the distances between two adjacent second planes 522 and the second mounting seat 51 are different. The first plane 422 is used to contact the surface of the pin 21 facing the first abutting surface 421, and the second plane 522 is used to contact the surface of the pin 21 facing the second abutting surface 521. By setting the first abutting surface 421 to include multiple first planes 422 and the second abutting surface 521 to include multiple second planes 522, the surface of the pin 21 facing the first abutting surface 421 can be completely in contact with the first plane 422, and the surface of the pin 21 facing the second abutting surface 521 can be completely in contact with the second plane 522. When the width of the pin 21 is relatively large, for example, greater than 2 mm, the gap between the pin 21 and the first abutting surface 421 and the second abutting surface 521 can also be effectively avoided.

[0053] Furthermore, the width of the first plane 422 and the width of the second plane 522 are greater than the width of the first pin 21. In this way, after the semiconductor intermediate structure is placed on the mold, even if the position of the semiconductor intermediate structure is offset to a certain extent, it can be ensured that the surfaces of the pins are all in contact with the first plane 422 and the second plane 522.

[0054] In one embodiment, Figure 6 As shown, the first abutting surface 421 includes a first connecting surface 423 located between two adjacent first planes 422 and outside all the first planes 422. The first connecting surface 423 is a non-planar surface, and may be roughly the same shape as the corresponding area of ​​the outer convex surface 32 of the plastic encapsulation layer 30. The area corresponding to the outer convex surface 32 of the plastic encapsulation layer and the first connecting surface 423 refers to the area in the outer convex surface 32 of the plastic encapsulation layer corresponding to the first connecting surface 423 in the width direction of the first abutting surface. In other embodiments, the first connecting surface 423 may be a plane. The cross section of the first abutting surface 421 perpendicular to its length direction is an arc whose vertex is located on the first abutting surface 421 or on the first plane 422.

[0055] In one embodiment, Figure 6 As shown, the second abutting surface 521 includes a second connecting surface 523 located between two adjacent second planes 522 and outside all second planes 522. The second connecting surface 523 is a non-planar surface, and may be roughly the same shape as the corresponding area of ​​the inner concave surface 31 of the plastic encapsulation layer 30. The area corresponding to the inner concave surface 31 of the plastic encapsulation layer and the second connecting surface 523 refers to the area corresponding to the second connecting surface 523 of the inner concave surface 31 of the plastic encapsulation layer in the width direction of the second abutting surface. In other embodiments, the second connecting surface 523 may be a plane. The cross section of the second abutting surface 521 perpendicular to its length direction is an arc whose vertex is located on the second abutting surface 521 or on the second plane 522.

[0056] In one embodiment, Figure 5 As shown, the first abutting surface 421 has a first symmetric plane 424, the first abutting surface 421 includes two opposite first side edges 425, and the two first side edges 425 are in the same plane, the first symmetric plane 424 is perpendicular to the plane where the two first side edges 425 are located and parallel to the first side edges 425, and the first abutting surface 421 is symmetrical about the first symmetric plane 424. Since the warping degree of both sides of the plastic encapsulation layer is the same during the warping process, the relative inner concave surface and outer convex surface of the plastic encapsulation layer both have symmetric planes perpendicular to the substrate, and the position of the pin changes with the warping of the plastic encapsulation layer, designing the first abutting surface 421 into the above shape helps to improve the fit between the pin and the first abutting surface 421.

[0057] In one embodiment, Figure 5As shown, the second abutting surface 521 has a second symmetric surface 524, the second abutting surface 521 includes two opposite second side edges 525, and the two second side edges 525 are in the same plane, the second symmetric surface 524 is perpendicular to the plane where the two second side edges 525 are located and parallel to the second side edges 525, and the second abutting surface is symmetrical about the second symmetric surface 524. Such a configuration helps to improve the fit between the pin and the second abutting surface 521.

[0058] In one embodiment, the shapes of the first abutting surface 421 and the second abutting surface 521 are substantially the same as the shape of the warped surface of the plastic encapsulation layer. Figure 3 As shown, the cross section of the warped surface of the plastic encapsulation layer 30 in the direction parallel to its length direction is an arc, and the arc includes a first endpoint 301 and a second endpoint 302, and the first endpoint 301 and the second endpoint 302 are on the same straight line 303. The maximum distance from a point on the arc to the straight line 303 is Y. After a large amount of data fitting, it is known that the ratio of the length of the plastic encapsulation layer to the length of the substrate in the semiconductor intermediate structure is X, and Y and X satisfy the following relationship: Y=a 1 X 2 +b 1 X+c 1 , its graph is a parabola. Where 0.0350<a 1 <0.0500,0.0010<b 1 <0.2000,-0.1900<c 1 <-0.0500, 1.05<X<3.00. It can be seen that within the value range of the above parameters, the value of Y is small, the warping degree of the plastic packaging layer is small, and the concave degree of the first abutting surface and the convex degree of the second abutting surface are small, which can avoid the problem of poor fit with the pin due to the large concave degree of the first abutting surface and the convex degree of the second abutting surface.

[0059] In one embodiment, Figure 4 As shown, the first abutment portion 42 is provided with a first groove 426 recessed toward the first mounting seat 41, and the second abutment portion 52 is provided with a second groove 526 recessed toward the second mounting seat 51. After the first sub-mold 40 and the second sub-mold 50 are molded together, the first groove 426 and the second groove 526 form a receiving cavity, and the plastic encapsulation layer 30 of the semiconductor intermediate structure is accommodated in the receiving cavity.

[0060] In one embodiment, Figure 4As shown, the first abutting portion 42 is provided with two first abutting surfaces 421, which are located at opposite sides of the first groove 426; the second abutting portion 52 is provided with two second abutting surfaces 521, which are located at opposite sides of the second groove 526. Each first abutting surface 421 abuts against the pin 21 located at the same side of the first groove 426, and each second abutting surface 521 abuts against the pin 21 located at the same side of the second groove 526.

[0061] In one embodiment, Figure 4 As shown, the first sub-mold 40 also includes a tool 43, which is mounted on the first mounting seat 41, and the blade 431 of the tool 43 and the first abutment surface 421 are located on the same side of the first mounting seat 41; the blade 431 of the tool 43 is concave in the direction of the first mounting seat 41. The tool 43 can apply a force to the pin 21 to deform the pin to obtain a pin of a target shape. The length direction of the tool 43 is the same as the length direction of the first abutment surface, and the lengths of the two can be roughly the same. Since the blade 431 of the tool 43 is concave toward the first mounting seat 41, after the blade 431 of the tool 43 contacts each pin located on the same side of the plastic packaging layer, it has a better fit with the surface of the pin facing the blade 431.

[0062] Furthermore, the shapes of the blade 431 of the tool 43 and the first abutting surface 421 may be substantially the same, which will not be described in detail herein.

[0063] In one embodiment, Figure 4 As shown, the second sub-mold 50 further includes a support portion 53, which is mounted on the second mounting seat 51, and includes a support surface 531, which is located on the same side of the second mounting seat 51 as the second abutting surface 521; the support surface 531 is used to abut against the pin 21, and the area where the pin 21 abuts against the support surface 531 is located on the side away from the plastic encapsulation layer 30 where the area abuts against the second abutting surface 521; the support surface 531 protrudes in a direction away from the second mounting seat 51. The support portion 52 can support the pin 21 to prevent the pin 21 from being deformed undesirably during the process of the tool 43 processing the pin 21. The length direction of the support portion 53 is the same as the length direction of the second abutting surface 521, and the lengths of the two can be substantially the same. Since the support surface 531 of the support portion 53 protrudes toward the second mounting seat 51 , after the support surface 531 of the support portion 53 contacts the pins on the same side of the plastic packaging layer, the support surface 531 of the support portion 53 has a better fit with the surface of the pins facing the support surface 531 .

[0064] Furthermore, the shapes of the support surface 531 of the support portion 53 and the second abutting surface 521 may be substantially the same, which will not be described in detail herein.

[0065] In one embodiment, Figure 4 As shown, the first sub-mold 40 further includes a positioning portion 44, which is mounted on the first mounting seat 41, and the end of the positioning portion 44 and the first abutting surface 421 are located on the same side of the first mounting seat 41; the second sub-mold 50 may be provided with a positioning groove (not shown). After the first sub-mold 40 and the second sub-mold 50 are molded together, the end of the positioning portion 44 is positioned in the positioning groove to prevent the first sub-mold 40 and the second sub-mold 50 from moving relative to each other.

[0066] The present application also provides a method for preparing a mold for manufacturing a semiconductor structure, and the method is used to prepare the mold described in the above embodiment. Figure 3 As shown, in the semiconductor intermediate structure, the arc line of the warping surface of the plastic encapsulation layer 30 includes a first endpoint 301 and a second endpoint 302 , and the first endpoint 301 and the second endpoint 302 are on the same straight line 303 .

[0067] like Figure 7 As shown, the preparation method includes the following steps 110 to 130.

[0068] In step 110, a plurality of semiconductor intermediate structures are provided. For each semiconductor intermediate structure, distance data corresponding to a plurality of points in the arc of the warping surface are determined. The distance data corresponding to each point includes a first distance between the point and the straight line, and a second distance between the point and a target point on the straight line in a direction parallel to the straight line.

[0069] In step 120, data information characterizing the depth of the first abutting surface being concave toward the first mounting seat and the height of the second abutting surface being protruded away from the second mounting seat are determined according to the distance data of the plurality of semiconductor intermediate structures.

[0070] In step 130 , the first abutting surface and the second abutting surface are prepared according to the data information, and the first abutting surface and the second abutting surface are prepared.

[0071] The preparation method of the mold for manufacturing a semiconductor structure provided in an embodiment of the present application first determines the first distance and the second distance corresponding to multiple points in the arc of the warping surface of the plastic layer in multiple semiconductor structures, and then determines data information characterizing the depth of the inward concave of the first abutment surface toward the first mounting seat and the height of the protrusion of the second abutment surface away from the second mounting seat according to the first distance and the second distance corresponding to each point. The first abutment surface and the second abutment surface prepared according to the data information match the shape of the inner concave surface of the plastic layer, and the distances between the multiple pins located on the same side of the plastic layer and the inner concave surface of the plastic layer are roughly the same, so that the multiple pins located on the same side of the plastic layer have a better fit with the first abutment surface and the second abutment surface, and the gap between the pins and the first abutment surface and the second abutment surface can be reduced or eliminated, thereby improving the problems of unexpected deformation and breakage of the pins, and improving the yield of the semiconductor structure.

[0072] In one embodiment, in step 110 , the plurality of semiconductor intermediate structures are the same structure. For example, the types of chips, the sizes of plastic encapsulation layers, the sizes of substrates, etc. in different semiconductor intermediate structures are the same.

[0073] In one embodiment, in step 110, the distance data corresponding to multiple points in the arc of the inner concave surface can be determined, and the distance data corresponding to multiple points in the arc of the outer convex surface can also be determined, or the distance data corresponding to multiple points in the arc of the inner concave surface and the distance data corresponding to multiple points in the arc of the outer convex surface can be determined at the same time.

[0074] In one embodiment, the target point on the straight line 303 may be any point on the straight line, for example, the target point may be the first endpoint 301 or the second endpoint 302 .

[0075] In one embodiment, for each semiconductor structure, the first distance and the second distance corresponding to a plurality of points in the arc line of the inner concave surface can be determined by measurement. Figure 3 As shown, the target point is the first endpoint 301, a point on the arc corresponds to a first distance h, and a corresponding second distance d.

[0076] In one embodiment, the data information includes an equation of the first distance with respect to the second distance. The step 120 of determining the data information characterizing the depth of the first abutting surface being concave in the direction toward the first mounting seat and the height of the second abutting surface being protruded in the direction away from the second mounting seat according to the distance data of each of the plurality of semiconductor structures comprises the following process: fitting an equation of the first distance with respect to the second distance according to the distance data of the plurality of semiconductor structures.

[0077] In one embodiment, the equation may be a quadratic equation, and the equation may be y=a2 x 2 +b 2 x+c 2 , whose graph is a parabola.

[0078] In one embodiment, the step of determining the shape of the first abutment surface and the shape of the second abutment surface according to the data information includes the following process: determining the shapes of the first abutment surface and the second abutment surface according to the equation, so that the shape of the cross section of the first abutment surface in a direction parallel to its length direction matches the equation, and the shape of the cross section of the second abutment surface in a direction parallel to its length direction matches the equation.

[0079] In one embodiment, the shape of the cross section of the first abutting surface in a direction parallel to its length direction matches the equation, which means that the cross section of the first abutting surface parallel to its length direction may be a part of the image of the equation (i.e., a parabola), and the midpoint of the first abutting surface coincides with the vertex of the parabola. The shape of the cross section of the second abutting surface in a direction parallel to its length direction matches the equation, which means that the cross section of the second abutting surface parallel to its length direction may be a part of the image of the equation (i.e., a parabola), and the midpoint of the second abutting surface coincides with the vertex of the parabola.

[0080] In one embodiment, the first abutting surface and the second abutting surface obtained by step 130 are both arched. Figure 4 shown.

[0081] In one embodiment, after step 130, the preparation method further includes the following steps: forming a plurality of first planes arranged at intervals on the first abutting surface, wherein the plurality of first planes are arranged in the length direction of the first abutting surface; forming a plurality of second planes arranged at intervals on the second abutting surface, wherein the plurality of second planes are arranged in the length direction of the second abutting surface. Figure 5 The first abutting surface 421 and the second abutting surface 521 are shown.

[0082] In one embodiment, the first sub-mold further comprises a tool, the tool is mounted on the first mounting seat, and the blade of the tool and the first abutment surface are located on the same side of the first mounting seat; the data information further represents the depth of the blade concave in the direction of the first mounting seat; the preparation method further comprises: determining the shape of the blade according to the data information, and preparing the blade. The blade of the prepared tool and the first abutment surface may have substantially the same shape.

[0083] In one embodiment, the second sub-mold further comprises a support portion, the support portion is mounted on the second mounting seat, the support portion comprises a support surface, the support surface and the second abutment surface are located on the same side of the second mounting seat; the data information further represents the height of the support surface protruding in the direction away from the second mounting seat; the preparation method further comprises: determining the shape of the support surface according to the data information, and preparing the support surface. The shape of the support surface of the prepared support portion and the second abutment surface can be substantially the same.

[0084] The embodiment of the method for preparing a mold for manufacturing a semiconductor structure provided in the embodiment of the present application and the embodiment of the mold for manufacturing a semiconductor structure belong to the same inventive concept, and the description of relevant details and beneficial effects can be referred to each other, and will not be repeated here.

[0085] It should be noted that in the accompanying drawings, the sizes of layers and regions may be exaggerated for clarity of illustration. It is also understood that when an element or layer is referred to as being "on" another element or layer, it may be directly on the other element, or there may be an intermediate layer. In addition, it is understood that when an element or layer is referred to as being "under" another element or layer, it may be directly under the other element, or there may be more than one intermediate layer or element. In addition, it is also understood that when a layer or element is referred to as being "between" two layers or two elements, it may be the only layer between the two layers or two elements, or there may also be more than one intermediate layer or element. Similar reference numerals throughout the text indicate similar elements.

[0086] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the disclosure disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0087] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A mold for manufacturing a semiconductor structure, the mold is used to process a semiconductor intermediate structure to obtain a semiconductor structure; the semiconductor intermediate structure comprises a substrate, a lead frame, a chip and a plastic layer, the lead frame and the chip are located on the substrate, the lead frame comprises a plurality of pins, the plastic layer encapsulates the substrate, the chip and the lead frame, and the pins are exposed from the plastic layer; It is characterized in that The mold for manufacturing a semiconductor structure comprises a first sub-mold and a second sub-mold; The first sub-mold includes a first mounting seat and a first abutting portion mounted on the first mounting seat, the first abutting portion includes a first abutting surface, and the first abutting surface is concave toward the direction of the first mounting seat; The second sub-mold includes a second mounting seat and a second abutting portion mounted on the second mounting seat, the second abutting portion includes a second abutting surface, and the second abutting surface protrudes in a direction away from the second mounting seat; the first abutting surface and the second abutting surface are used to abut against one of the two opposite surfaces of each of the pins located on the same side of the plastic packaging layer when the semiconductor intermediate structure is placed in the mold.

2. The mold for manufacturing a semiconductor structure according to claim 1, It is characterized in that The first abutting surface and the second abutting surface are both arched.

3. The mold for manufacturing a semiconductor structure according to claim 1, It is characterized in that In the length direction of the first abutting surface, the first abutting surface is provided with a plurality of first planes arranged at intervals, and the distances between two adjacent first planes and the first mounting seat are different; in the length direction of the second abutting surface, the second abutting surface is provided with a plurality of second planes arranged at intervals, and the distances between two adjacent second planes and the second mounting seat are different.

4. The mold for manufacturing a semiconductor structure according to claim 1, It is characterized in that The first abutting surface has a first symmetric plane, the first abutting surface includes two opposite first side edges, and the two first side edges are in the same plane, the first symmetric plane is perpendicular to the plane where the two first side edges are located and parallel to the first side edges, and the first abutting surface is symmetrical about the first symmetric plane; The second abutting surface has a second symmetric plane, the second abutting surface includes two opposite second side edges, and the two second side edges are in the same plane, the second symmetric plane is perpendicular to the plane where the two second side edges are located and parallel to the second side edges, and the second abutting surface is symmetrical about the second symmetric plane.

5. The mold for manufacturing a semiconductor structure according to claim 1, It is characterized in that The first sub-mold also includes a tool, which is mounted on the first mounting seat, and the blade of the tool and the first abutment surface are located on the same side of the first mounting seat; the blade of the tool is concave inwardly toward the first mounting seat.

6. The mold for manufacturing a semiconductor structure according to claim 1, It is characterized in that The second sub-mold also includes a supporting portion, which is installed on the second mounting seat, and the supporting portion includes a supporting surface, and the supporting surface and the second abutting surface are located on the same side of the second mounting seat; the supporting surface is used to abut against the pin, and the area where the pin abuts against the supporting surface is located on the side of the area abutting against the second abutting surface away from the plastic packaging layer; the supporting surface protrudes in a direction away from the second mounting seat.

7. A method for preparing a mold for manufacturing a semiconductor structure, It is characterized in that The mold is used to process the semiconductor intermediate structure to obtain the semiconductor structure; the semiconductor intermediate structure includes a substrate, a lead frame, a chip and a plastic layer, the lead frame and the chip are located on the substrate, the lead frame includes a plurality of pins, the plastic layer encapsulates the substrate, the chip and the lead frame, and the pins are exposed from the plastic layer; the plastic layer is warped toward the surface away from the substrate where the plastic layer is exposed; the mold includes a first sub-mold and a second sub-mold; the first sub-mold includes a first mounting seat and a first abutting portion mounted on the first mounting seat, the first abutting portion includes a first abutting surface, the second sub-mold includes a second mounting seat and a second abutting portion mounted on the second mounting seat, the second abutting portion includes a second abutting surface; the first abutting surface and the second abutting surface are used to abut against one of the two opposite surfaces of the pins when the semiconductor intermediate structure is placed in the mold; the plastic layer has a warped surface, and the cross section of the warped surface in a direction parallel to the length direction of the plastic layer is an arc; the arc includes a first end point and a second end point opposite to each other, and the first end point and the second end point are on the same straight line; the preparation method includes: Providing a plurality of semiconductor intermediate structures, and determining distance data corresponding to a plurality of points in the arc for each semiconductor intermediate structure, wherein the distance data corresponding to each point includes a first distance between the point and the straight line, and a second distance between the point and a target point on the straight line in a direction parallel to the straight line; Determine, based on the distance data of the plurality of semiconductor intermediate structures, data information representing a depth of the first abutting surface being concave in a direction toward the first mounting seat and a height of the second abutting surface being convex in a direction away from the second mounting seat; The shape of the first abutting surface and the shape of the second abutting surface are determined according to the data information, and the first abutting surface and the second abutting surface are prepared.

8. The method for preparing a mold for manufacturing a semiconductor structure according to claim 7, It is characterized in that The data information includes an equation of the first distance with respect to the second distance; the data information characterizing the depth of the first abutting surface being concave in a direction toward the first mounting seat and the height of the second abutting surface being protruded in a direction away from the second mounting seat is determined according to the distance data of the plurality of semiconductor intermediate structures, including: fitting an equation of the first distance with respect to the second distance according to the distance data of the plurality of semiconductor structures; The determining the shape of the first abutting surface and the shape of the second abutting surface according to the data information includes: The shapes of the first abutment surface and the second abutment surface are determined according to the equation, so that the shape of the cross section of the first abutment surface in a direction parallel to its length direction matches the equation, and the shape of the cross section of the second abutment surface in a direction parallel to its length direction matches the equation.

9. The method for preparing a mold for manufacturing a semiconductor structure according to claim 8, It is characterized in that The first abutting surface and the second abutting surface prepared according to the data information are both arched; after the first abutting surface and the second abutting surface are prepared according to the data information, the preparation method further includes: A plurality of first planes arranged at intervals are formed on the first abutting surface, and the plurality of first planes are arranged in the length direction of the first abutting surface; a plurality of second planes arranged at intervals are formed on the second abutting surface, and the plurality of second planes are arranged in the length direction of the second abutting surface.

10. The method for preparing a mold for manufacturing a semiconductor structure according to claim 7, It is characterized in that The first sub-mold further includes a tool, the tool is mounted on the first mounting seat, and the blade of the tool and the first abutment surface are located on the same side of the first mounting seat; the data information further represents the depth of the blade concave in the direction toward the first mounting seat; the preparation method further includes: determining the shape of the blade according to the data information, and preparing the blade; and / or, The second sub-mold also includes a supporting portion, which is mounted on the second mounting seat, and the supporting portion includes a supporting surface, and the supporting surface and the second abutting surface are located on the same side of the second mounting seat; the data information also represents the height of the supporting surface protruding in the direction away from the second mounting seat; the preparation method also includes: determining the shape of the supporting surface according to the data information, and preparing the supporting surface.

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