TWI265608B - Semiconductor package with heat sink - Google Patents

Abstract

A semiconductor package with a heat sink is proposed, in which at least a chip and the heat sink covering the chip are mounted on a substrate. The heat sink is composed of a planar portion and a supporting portion extending from the periphery of the planar portion, and at least a recessed structure is formed on a surface of the support portion attached to the substrate. In addition, at least a bulger unit is disposed on a surface of the substrate, thereby fixing the heat sink on the substrate with tight fit through a recessed structure and a bulger unit. Thus, the heat sink is fixed stably on the substrate for reducing the cost.

Description

1265608 V. INSTRUCTION DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a conductive guide having a heat sink which is capable of stably attaching a heat sink to prevent it from falling off: a car member, a special member. , 洛洛+conductor package Prior Art Flip-Chip Bau Grid =: The conductor package is a package with both flip chip and ball grid arrays. So that the action table of at least one of the wafers can be electrically connected to one of the substrates (Substrate) from the majority of the bumps, and on the other surface of the substrate. Most of the implants are used as input/output (I/O) solder balls (Solder Ball); this package structure can greatly reduce the size, while also reducing the design of the conventional wire (W ire ), and can reduce the impedance increase Electrical to avoid signal degradation during transmission' has thus become the mainstream packaging technology for next generation wafers and electronic components. Due to the superior characteristics of the flip-chip ball grid array package, many of them are used in the multi-chip package of the accumulation system to meet the volume and operation requirements of the electronic component, but such electronic components Due to its high frequency operation characteristics, the thermal energy generated during the operation process will be higher than that of the general package. Therefore, whether the heat dissipation effect is good or not becomes an important key to the quality of the package technology. In the conventional method, the heat sink is directly bonded to the substrate by using an adhesive material such as an adhesive or a solder, and the area of the heat sink is larger than the area of the wafer. Receive better heat dissipation performance.

1757] Product. ptd Page 7 1265608 V. Description of the Invention (2) For example, the semiconductor package of U.S. Patent No. 5,311,040, shown in Fig. 9, provides a wafer 6 on a substrate 60. 2, a plurality of recesses 64 are disposed outside the area of the joint, and the recesses 64 are filled with the adhesive 66 to provide the heat sinks 6 8 for bonding. The support portion 6 8 a of the heat sinks 6 8 The heat sink 6 8 is firmly clamped to the substrate 60 by the adhesive bonding of the adhesive 6 6; the heat sink and the substrate are the same in the bonding method. The actual bonding area is not large, which is a major limitation on the adhesion stability. Especially when the substrate is connected with other passive components to improve its electrical performance, it will be further reduced. The bonding area between the substrate and the heat sink, so that the heat sink is extremely easy to be subjected to a subsequent impact test (S h 〇ck T est ) or other external force shock, and is subjected to a shear force and falls off from the substrate, resulting in poor product. In order to solve this problem, U.S. Patent No. 6,099,9,61, discloses a package structure for mechanically reinforcing the joint stability of the heat sink, as shown in FIG. A resilient hook leg 7 2 is formed on the edge of a heat sink 70, and the heat sink 70 is snapped onto the wafer 74 to improve the bonding of the heat sink 70. However, this design only considers the robustness of the heat sink 70, but causes greater damage to the package. This is due to the coefficient of thermal expansion (CTE) of the heat sink 70 and the wafer 74. The contact surface 76 and the hook leg 7 2 of the heat sink 70 are extremely easy to be tested in a subsequent high temperature process or reliability test because of the difference in thermal deformation from the wafer 74. The wafer 74, in turn, causes cracking of the wafer 74. In summary, how to reduce the contact area between the heat sink and the wafer

17571 ······································································································ It may fall off. However, in the above statement, it must reduce the manufacturing cost of the board on the substrate, and if it does, it will also cause the seal to be related to the adhesion and the original part of the wafer and the substrate. The surface is filled with a recess of 94, which is increased. However, due to the filling in the groove, the amount of heat dissipated is easily caused by the amount of glue applied. On the other hand, the adhesion of the heat sheet is only slightly higher, and it is still difficult to cope after Unable to solve the adhesion of the heat sink, it is obvious that an important research and development party has proposed several kinds of hot stamps of the US Patent No. 5, 3, 6, 6, 3, 3, which are shown in the above figure. The corresponding position of the substrate 8 2 is embedded with a bolt 8 8 to prevent the hole assembly 80 from being used in addition to the hole assembly, and the function of the hole is developed. Excessive external parts of the plastic parts, in the practice of direct continuous impact sheet off the fixed piece of the fixed area to open the line layout in the process can be expected so far, to avoid, Figure 12 is in the flow The film 90 and the adhesive are often unable to occur on the glue. It is also found that the test and the operation of the test are carried out. The conventional structure of the heat sink is provided with holes. This design is not only the area but also the external moisture. Rate problem. Gradually changing the fixed heat dissipation will also increase the base or contaminant intrusion, that is, one of the hot-sheet adhesives will dissipate the correct adhesive material, and the hot piece will not pass through the blockage detection of the material of the base material material. The rubber overflow type design is adhered to the process of using the heat sink design piece while the cover plate of the damage design is 9 2 contacted with the contact area of the groove. It is desirable to present the sizing of the closed adhesive to the moving environment on the provided discrete substrate on the substrate. 111

]757] 夕夕.ptd Page 9 1265608 V. Description of the invention (4) The recent development of the heat sink 9 8 is such that the open end of the heat is forced to dissipate the heat sink 9 The effect of 0 is fixed, and it is still not the shrinkage of existing mechanical manufacturing or the increasing number of grooves. The small size of the structure is difficult to control, although it is theoretically difficult to control, it is difficult to achieve In addition, the heat sink is adhered to the process cost of other processes, which is in line with the needs of the industry. Therefore, in consideration of the package, in order to reduce the cost and low cost, the related research and development field [invention] The heat sheet is prevented from shifting. The second embodiment of the present invention is directed to the first groove having a slightly smaller heat member 90 and the polarity, and the design of the pattern is changed to a new design between the inner wall substrate 92. In the practice of mass production, there is a need to form a medium-skilled field, the effect of manufacturing, the limitation of the production of technical disciplines, or the difficulty of making a decision. It is said that the hot film does not require 'there is no need for urgent problems. Therefore, the only way to improve the process of the process and its success is that the average person can commercialize the diameter of the tail groove, and the joint is indeed demanded. Moreover, the 1 3 figure is extremely demanding, and often solves all the improvements. The groove is used to increase the heat of the anchor. The reason for the continuous heat change is as difficult as the half, but as the structure is fixed, the piece is lifted. Adhesion, the accuracy of the tapered conductor sealing and sealing can also be found that if the problem is solved for the existing problem, but the consumption is huge, there is no need to fully open 4 to emit a semiconductor with a heat sink, and at the same time, the process can be reduced. To reduce the yield of the wafer and the substrate, the stone bird is the subject of the problem. ~ = ί - Provides a semiconductor package with a heat sink that can be firmly connected to the fly-off. The purpose is to provide a low-cost heat sink

1265608 V. Description of the invention (5) Semiconductor package. Another object of the present invention is to securely attach the heat sink in a road layout. Still another object of the present invention is a semiconductor package having a heat sink. Another object of the present invention is to prevent the adhesive material from overflowing onto the substrate for other purposes. The conductor package includes: a second surface of the substrate; at least one wafer, and is electrically connected to the substrate; a surface of the support portion extending from the edge of the ridge portion, and a space surrounded by the wafer plate is formed with at least one surface recessed on the surface of the substrate, so that the convex portion Forming a pattern of tight engagement; and a plurality of solder balls are implanted on the surface of the contact structure formed by the recessed structure, which may be a groove-shaped groove, a closed annular groove, and a formation The semiconductor package having a recessed structure formed with a recessed structure to form a tightly-bonded die provides a semiconductor package that does not affect the wires on the substrate, and provides a semiconductor package that does not cause wafer cracking. A semiconductor package having a dispersion of a heat sink and having a dispersion of a 4 sheets; the present invention provides a heat sink The semi-five has a first surface and a first surface is disposed on the first surface of the substrate. The film has a flat portion and a flat portion 5 to be attached to the substrate and covered by the support portion. And a structure in which the support portion is in contact with the substrate, wherein at least one protrusion forms a heat sink, and the recessed structure and the first surface fixed to the substrate are on the second surface of the substrate The support portion of the heat sink and the form of the substrate, such as the form of a rectangular groove strip or a cylindrical recess 0, the position of the convex first surface for receiving the heat sink, and the heat sink 0 The convex is based on the concave knot

17571 .品.ptd Page 11 1265608 V. INSTRUCTIONS (6) The outer contour is designed to be in the form of a convex or cylindrical projection (ie, having the same contour as the corresponding recessed structure). Since the protrusion is located at a corresponding position where the support portion of the heat sink is formed with a recessed structure, and the horizontal cross-sectional contour area of the protrusion is slightly larger than the corresponding cross-sectional area of the recess structure. Therefore, the heat sink can be tightly coupled to the protrusion of the surface of the substrate by the concave structure, and the heat sink is fixed to the first surface of the substrate, and is tightly fitted to the substrate by the protrusion. After the recessed structure, the restoring stress generated by the compression of the inner wall of the recessed structure causes the concave inner wall of the recessed structure to have a large frictional force with the convex surface of the convex, thereby further stably attaching the heat sink to the surface of the substrate. The utility model can effectively prevent the heat sink from being displaced or falling off due to the influence of external force, and has the advantages of simple process and low cost. [Embodiment] The embodiments of the present invention are described below by way of specific examples, and those skilled in the art can readily understand other advantages and effects of the present invention from the disclosure. The present invention may be embodied or applied by other specific embodiments, and various modifications and changes can be made without departing from the spirit and scope of the invention. 1A is a cross-sectional view of a preferred embodiment of the present invention having a heat sink semiconductor package, which is a flip chip ball grid array package 1 (FCBGA) including a chip carrier (Chip Carrier). The substrate 10 is electrically connected to the substrate 10 by the bumps 1 1 and is attached to the wafer 1 2 on the first surface 10 a of the substrate 10 , and the underfill filled around the bumps 1 1

1757] bite. ptd page 12 1265608 5. invention description (7) (Under f 1 1 1 ) insulating material 13 3, formed on the first surface of the substrate 1 〇a of the column 1 4, by the column i 4 a square heat sink 15 5 ′ fixed to the first surface 丨〇 a of the substrate 以及 and a second surface 1 〇 b implanted on the substrate 1 电 and electrically connected to the plurality of bumps 1 1 a plurality of solder balls 16; wherein the square fins 15 have a square flat portion 5a and an annular support portion 丨5b extending from the flat portion 1 toward the substrate 10 to support the support The portion 15 is placed on the first surface 丨0a of the substrate 1 , and a rectangular recess 17 is formed on the annular support portion 15b for tightly engaging the protrusion 14 of the first surface 1 〇 a of the substrate. The square heat sink 15 is fixed to the first surface 丨〇a of the substrate. The heat sink 15 is made of a nickel-plated copper material JNi-Plat/d-Cu, and the flat portion 15a thereof is Having a thickness of about 2 〇 to 4 〇 mil mi 1 ), at the same time, the thermal expansion coefficient of the nickel-copper material of the bond is also related to the material of the slab (for example, epoxy resin, polyamine, BT resin) The FR4 tree force 曰f) is similar, so that the possibility of warpage or delamination of the support portion 15b of the heat sink 15 and the substrate 1 is minimized, wherein the height of the portion 15b is It can be designed to be 1〇 to 4〇mil (mil), the value of which is ^='thickness or the number of layers to be configured; in addition, the heat sink 15 is flat ~ ° 5a is the thermal adhesive shown by the figure And bonding to the wafer 丨2 to form an opposite surface of the wafer 丨2, so as to transfer the wafer 12 to the flat portion a5a of the heat sink 丨5 by the thermal conductive adhesive 18.散 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶 埶On the surface in contact with the substrate 1 ,, respectively, opposite to the flat portion

17"1 矽品.Ptd Page 13 1265608 V. Description of the invention (8) The position of the edge side and the corner edge side is formed with a first rectangular groove 17a and a second rectangular groove 17b. As shown in Fig. 2A As shown in FIG. 2B, the first and second rectangular recesses 17a, 17b' are formed by a rectangular punch 21 (Punch) having a vertical cross-sectional width L1 for supporting the substrate 1 at the support portion 15b of the heat sink 15. A stamping step is performed on the surface to form a rectangular recess 17 having a concave inner wall width of ^. The 3A to 3C drawings are diagrams showing the projection i 4 formed on the first surface 丨〇a of the substrate. As shown in FIG. 3A, the thermosetting colloid material 19 is applied before the first surface 1a of the substrate is used to connect the fins 15 to the support portion 15a. Fixture pressing laying = plate number: surface 1 〇a of thermosetting colloidal material 197, the colloidal material t 19 is squeezed and filled into the groove (2) of the jig 22, and then 盥 1 Λ ΰ f The jig 22 is formed with a groove 23, and the surface of the support portion 15b of the political fin 15 is formed with a rectangular groove 17 having a horizontal cross-sectional profile and a depression. And the recessed inner wall 'L2 of the groove 23 is slightly larger than the recess Γΐ width of the rectangular groove 17 of the fin support portion b5b. As shown in the pre-C/C, the jig 22 is removed. After that, you can pre-connect the blood on the surface of the base of the brother-in-law. # u τ r, 丄, upper Λ; Λ J ^ 1 4. The convex column used to form the convex main two-two I and L2 There is no special restriction on the material to be taken, and the materials of $ & 14 can be selected, and the different types of colloidal materials such as the second &resin; and other suitable hardening conditions enable the colloidal material to be hardened and formed. ;to make:

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Page 14 1265608 V. Description of invention (9)

As shown in Fig. 4, the wafer 12 is electrically connected to the first surface 1 Oa of the substrate 10 through the bumps 1 1 and the insulating material 丨 3 is filled in the bumps. The wafer 12 is electrically connected to the first surface 1 of the substrate, and the hot glue 18 is further applied to the opposite surface of the wafer 12 formed with the bumps 11 for the wafer 1 2 The generated heat is conducted to the flat portion 15 a of the heat sink i 5 and is dissipated to the outside. Then, the heat sink 1 5 can be fixed to the first surface 10 a of the substrate 1 by using the protrusions 14 formed on the first surface 10 a of the substrate. The protrusions are 0 · 0 2 in the groove and the inner wall of the groove - the surface; = the column 1 4 is opened > the first surface of the substrate 1 〇a is pre-connected to the heat sink ^, the portion 1 5b has a rectangular groove 丨Corresponding position of 7 and the I degree L 2 of the stud is slightly larger than the width L1 of the recessed inner wall of the rectangular recess 17; for the political fin 15 , the rectangular recess 17 of the supporting portion 15 b and the substrate are The rib 1 14 of the 〇a forms a pattern of tight engagement and is fixed to the surface of the Μ__士10 a. The difference between the widths of the concave inner walls of the rectangular recesses 17 and the convexity L 2 of 4 is '0' 〇1 to 〇· 〇 5 mm, preferably ^ is better to make the studs 1 4 is tightly fitted to the rectangular recess 17 and is compressed by the soil. Based on the restoring stress of the stud 14 4, the friction between the stud and the recess is increased, so that the fin 15 is more firmly attached to the first substrate. 〇 a 〇 heat sink is widely used in the conventional method only by the adhesive material adhered to the surface of the substrate, too, and by the anchor lock on the surface of the substrate. In the semiconductor package, the heat sink 1 is connected to the first surface 10a of the substrate, and the tenon 14 is tight. $ ”- After the rectangular groove 1 7 , the recovery due to compression should be

17571石夕品.ptd

Page 15 1265608 V. INSTRUCTIONS (10) Force (as indicated by the arrow in Fig. 5) increases the friction between the concave inner wall of the rectangular recess 17 and the convex surface of the stud 14 and strengthens at the same time The heat sink 15 is connected to the first surface 10 a of the substrate to prevent the heat sink 15 from being shaken off or deflected. In the semiconductor package having the heat sink of the present invention, the thermosetting colloidal material 19 which is applied to the first surface of the substrate 10 a is first hardened to form the studs 14 and then tightly supported to the fins. In the rectangular recess 1 7 of the portion 1 5 b, the heat sink 1 5 is fixed to the first surface 1 〇 a of the substrate instead of directly filling the fluid adhesive agent into the groove of the heat sink. Therefore, it is possible to avoid the situation in which the glue is excessively applied and the glue overflows. Furthermore, in the semiconductor package having the heat sink of the present invention, the heat sink 15 is not positioned by the contact relationship with the wafer 12, so that the wafer 1 is not pressed in the subsequent high temperature process, resulting in the wafer 1 2 rupture. In addition, since the design of the rectangular groove 17 is formed by a simple stamping process as described above, it is only necessary to use a suitable punching head to mass-produce at a low cost, and it is not as known as the tail groove. In the same way, additional process costs are required, and it is difficult to achieve mass production scale. In the semiconductor package having the heat sink of the present invention, the recessed structure formed on the support portion of the heat sink is not only a rectangular recess as described in the above preferred embodiment, but also a recessed structure of other different types. In the second embodiment of the present invention, the annular support portion 35b of the heat sink 35 is used for forming a horizontal cross section on the surface of the substrate 1 which is in contact with the substrate. A circular cylindrical cavity 37. The cylindrical recess 37 is located on the edge side and/or the corner side of the flat portion 35a of the heat sink 35.

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5. Inventive Description (11) Similarly, in the conventional embodiment, the first surface 丨〇a of the substrate 10 is pre-attached to the support portion 35b of the heat sink 35, and a cylindrical recess 3 is formed. Corresponding position of 7 is also formed with a cylindrical protrusion having a horizontal cross section and a profile slightly larger than the horizontal cross-sectional area of the cylindrical cavity 37, so that the heat sink 35 has a cylinder by the support portion 3 5 b The recess 37 forms a tight fit structure with the corresponding cylindrical bump formed on the first surface 1 〇a of the substrate, and is fixed on the surface of the substrate 1 by using a square heat sink as an example, the support portion The recessed structure is not limited to the rectangular recesses 1 7 a, 1 7 b shown in FIG. 1B and the cylindrical recesses 3 Ί 1 shown in FIG. 6 , as shown in FIG. 7 , which is formed on the support portion 4 5 b The recessed structure may also be an elongated groove 41 corresponding to the edge side of the flat portion 45 a and having a horizontal tangent shape, whether it is a rectangular recess 17 , a cylindrical recess 37 , or a long strip The number of the grooves 47 is not the same as the opening position. Limiting, it is also possible to use different types of recessed structures, or to create air holes in the recessed structure, to reduce the gas resistance in the recessed structure when the heat sink is fixed to the surface of the substrate; but the support portion of the heat sink forms a concave structure The position is preferably 1 with a certain degree of symmetry to achieve a uniform distribution of the locking force of the protrusion to the heat sink 5 to achieve a smooth fixing effect. Furthermore, as shown in FIG. 8, in another embodiment of the present invention, the recessed structure of the support portion 5 5 b of the release sheet 5 5 surrounds the closed annular groove 57 of the flat portion 5 5 & ° In fact, the recessed structure formed on the support portion of the heat sink is an elongated groove 47, or a closed annular groove 57, as long as the surface of the substrate is formed to have the same horizontal cross-sectional profile as the recessed structure. And the convexity of the area is large, so that the heat dissipating member can form a tightly fitting pattern with the corresponding convex surface of the substrate surface 1265608, the invention description (12), and smoothly fix the heat sink Connected to the surface of the substrate. Therefore, the type of the recessed structure and the appearance of the heat sink are not limited by the present invention. In summary, the semiconductor package with the heat sink of the present invention has the effect of stably connecting the heat sink, and the structural design thereof does not cause damage to the wafer and the substrate, thereby achieving the simple process and low cost. Advantages, to achieve mass production needs. The above examples are merely illustrative of the principles of the invention and its effects, and are not intended to limit the invention. Modifications and variations of the above-described embodiments can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention should be as set forth in the scope of the patent application to be described later.

17571 石夕品.ptd Page 18 1265608 Schematic description of the drawings Fig. 1 is a cross-sectional view of a package in which the fins are provided with a dovetail groove. 1 semiconductor package 10 substrate 10a substrate first surface 10b substrate second surface 11 bump 12 wafer 13 insulating material 14 stud 15 heat sink 15a flat portion 15b support portion 16 solder ball 17 rectangular recess 17a first rectangular recess 17b Second rectangular groove 18 Thermal paste 19 Colloidal material 21 Square stamping head 22 Fixture 23 Groove 35 Bulk sheet 3 5a Flat portion 35b Support portion 37 Cylindrical cavity 45 Heat sink 45a Flat portion 45b Support portion 47 Long concave Slot 55 Heat sink 5 5a Flat portion 55b Support portion 57 Closed annular groove 60 Substrate 62 Wafer 64 Groove 66 Adhesive 68 Bulk member 6 8a Support portion 70 Bulk sheet 72 Hook foot 74 Wafer 76 Contact surface

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Brief description of the figure 80 Heat sink 82 Substrate 84 Positioning hole 86 Positioning hole 88 Bolt 90 Heat sink 92 Substrate 94 Groove 96 Adhesive material 98 Dovetail groove structure 17571 Shi Xipin.ptd Page 21

Claims (1)

1265608 _ Case No. 92130885 丄月》J日___ VI. Patent application scope 1. A semiconductor package having a heat sink, comprising: a substrate having a first surface and an opposite second surface; at least one The chip is electrically connected to the first surface of the substrate and electrically connected to the substrate; the heat sink has a flat portion and a support portion extending from the edge of the flat portion to be attached by the support portion Forming, on the first surface of the substrate, the wafer in a space surrounded by the flat portion, the support portion and the substrate, wherein at least one recess is formed on the surface of the support portion in contact with the substrate The sidewall of the recessed structure is perpendicular to the first surface of the substrate; at least one protrusion is formed on the first surface of the substrate by using a fixture, and the sidewall of the protrusion is perpendicular to the first surface of the substrate, so that The heat sink is fixed to the first surface of the substrate by the concave structure and the protrusion; and a plurality of solder balls are implanted on the second surface of the substrate. 2. The semiconductor package of claim 1, wherein the recessed structure is a recess. 3. The semiconductor package of claim 2, wherein the protrusion is a stud. The singularity of the singularity of the slab of the slab of the slab of the slab. . 5. The semiconductor package of claim 4, wherein the protruding width L2 of the stud is greater than the recessed inner wall width L1 of the recess and 17571 (Revised Edition).ptc Page 22 1265608 _ Case No. 92130885 February of the 7S> Day Correction _ 6. The patent application range is 0. 0 2 mm. 6. The semiconductor package of claim 2, wherein the recess is located on an edge side of the corresponding flat portion. 7. The semiconductor package of claim 2, wherein the recess is located on a corner edge of the corresponding flat portion. 8. The semiconductor package of claim 1, wherein the recessed structure is a cylindrical recess. 9. The semiconductor package of claim 1, wherein the recessed structure is an elongated groove. The semiconductor package of claim 1, wherein the recessed structure is a closed annular groove. 1 1. The semiconductor package of claim 1, wherein the recessed structure is provided with air holes. 17571 (Revised Edition).ptc第23页