TWI237858B - Electrical device with elastic bumps and method for forming the elastic bumps - Google Patents

Abstract

An electrical device with elastic bumps and a method for forming the elastic bumps are provided. The electrical device comprises a plurality of elastic bumps formed on contact pads of a substrate. Each elastic bump includes an electrically insulated elastic body and conductive material(s). The elastic body has at least one through hole connecting to the corresponding contact pad. The conductive material is filled in the through hole and extended to top of the elastic body. Thus, the elastic bumps enable absorb the stress on mounting interface of the electrical device and improve outer electrical connection of electrical device.

Description

1237858 V. Description of the Invention (1) [Field of the Invention] The present invention relates to an electronic device with elastic bumps and a method for forming the elastic bumps, and particularly relates to a chip size package structure with elastic bumps. Reduce the filling [under fi 1 1 ing] step. [Prior art] The conventional electrical connection methods of electronic devices include external pin mating, external pin soldering, and bump surface bonding. Among them, bump surface bonding has a smaller bonding area and a higher terminal density. The distribution is particularly suitable for miniaturized and chirped chip size packages [Ch ip Sea 1 e Package], which is-forming metal bumps arranged in a matrix on the bonding surface of the wafer to connect them with power supply.

When the wafer is flipped and bonded to an external printed circuit board with its metal bumps, the thermal expansion coefficient [CTE] of the semiconductor wafer and the printed circuit board is quite different, which results in thermal stress at the bonding interface between the wafer and the printed circuit board. The block is prone to mechanical thermal fatigue [therma 1 fatigue], so usually after the wafer and the printed circuit board are combined, a filler material and an [underfiHing material] are filled between the two to absorb thermal stress. Reference is made to U.S. Patent No. 710, 071 'However, the conventional filling method of filling material is to allow the filling material to naturally flow between the wafer and the printed circuit board under a temperature rise and capillarity. The filling process requires sufficient flow time and accurate temperature control, so production efficiency will be affected. In U.S. Patent No. 6,075,290, a method is disclosed that does not require filling

1237858. --_______ V. Description of the invention (2) The electronic device of the filling material is a integrated circuit package structure [jc Package], and the contained wafer has a passivation layer and is exposed on the substrate. The conductive pad of the passive protective layer has an elastic protective layer [resilien1: protective layer] formed on the passive protective layer. The elastic protective layer forms an opening corresponding to the conductive pad and forms a bump base in the opening. [Under bump pad], and a metal bump is bonded to the bump base, such as tin-lead alloy [tin-lead a 11 〇y], using the housing protection layer to pick up the heat between the chip and the external printed circuit board However, the elasticity of the metal bump itself has not been improved, and the thermal stress generated in the metal bump may still thermally fatigue the metal bump. [Objective and Summary of the Invention] An electrically insulating elastic block having an external circuit board having a second purpose to improve electrical insulation. An elastic block having an elastic bump has the advantage of reducing the main purpose of providing an elastic block as a through hole. Its filling with non-essential sub-devices is to provide an elastic block as a through hole. It fills the electronic device filled with the bump itself with less filling material to provide a table function with good power supply. The electronic device provides a good power-supplying sub-device junction.] According to the present invention, a good flexibility is used to conduct, even if the surfaces are joined, so the present invention uses a good elasticity, to conduct, the interface of these interfaces Effect. Kind of elastic bumps The body of the bumps, filled with conductive material, can also be electrically connected on the plane. Kinds of elastic bumps, the body of the bumps, filled with conductive materials, elastically absorbs the electricity [underf i 1

I Another method of the present invention is to provide a bump method, the first purpose of which is to provide a method for forming a substrate on an electronic device.

V. Description of the invention (3) An elastic block with a through hole, and then filled with a conductive material in the through hole, so as to be large! The effect of making multiple elastic bumps on the same plane. In order to achieve H service, another purpose is to provide a wafer ruler. An elasticity is formed on the connection pads of the film: structure = block covers the corresponding connection pad, and the elastic block has =

Πΐ ::: conduction, so these elastic bumps can absorb the electric K filling material filling r Η has the effect of improving the elasticity of the bump itself and reducing the effect of the filling step. ^ The electronic device 4 with elastic bumps of the present invention, which includes a plurality of :: sexual projections &, is a connection pad formed on a substrate:

: Yes; elastic block and conductive material, the elastic block is a LI object: two elastic pairs of polymer organic oligo-through holes such as ΓΓ glue, table Ϊ: 'the elastic block has to ^ ^. K to the corresponding connection pad, The conductive material is filled in the through hole f extending to the top surface of the elastic block. The conductive material in the through hole is nickel, ^; palladium tin lead, silver glue or anisotropic conductive glue, etc.导电 The conductive material on the top surface of the elastic block is nickel, gold, silver, copper, palladium, or anisotropic conductive glue. Therefore, the electronic device with elastic bumps of the present invention is suitable for wafers, wafers, and printed circuits. Production of boards, ceramic substrates or films = the method of forming elastic bumps on electronic devices of the present invention, the steps of which are: 3: = a common substrate, such as a wafer, a printed circuit board, a substrate or a 2 'substrate -The surface has a plurality of connection pads; formed by printing, spin-coating, film adhesion, etc.-an electrically insulating elastic layer on the surface of the substrate,

Page 7 1237858 V. Description of the invention (4) Cover the connection pads; etch the elastic blocks on the elastic pads, and the elastic pads have a small j to form the corresponding connection pads provided on the connection pads; and use deep holes Plating, ^: through holes, which are connected to form a conductive material in the through holes.乇 ,, field filling or printing, etc. [Detailed description of the invention] Please refer to the attached drawings' The present invention will be based on the specific embodiments of the present invention, such as the description of the following embodiments: The electronic device of the block mainly contains A substrate is shown in FIG. 1 with an elastic bump 20 having an elastic convex plate 10. The substrate 10 is a K complex: a combination: the base [wafer], the printed circuit board [PCB]:; C lp] round,丨 You I board [ceram 1 c: thin film 'η⑴ ™]. In this embodiment, the electronic device with spring bumps is a wafer size package structure [S ^ cale Package], so the substrate 1 It is a chip such as DRAM, flash or ⑽R, such as memory, micro processor, microcontroller, or special application integrated circuit. A connection pad 12 is formed on one surface 11 of the substrate 10 (ie, active surface). , Such as aluminum pad [A1 pad] or copper pad [Cu pad]. Each of the elastic bumps 20 is formed on the corresponding connection pad 12. The elastic bump 20 has an electrically insulated elastic body 2! And a conductive material 23. The elastic block 2 1 It is an organic polymer with high electrical insulation and high elasticity, such as polyimide, benezo cyclobutene, polyacrylates, rubber or rubber. Silicone [si 1 ic ο ne], in this embodiment, the elastic block 21 is a semi-conical feci

m

Page 8 1237858 V. Description of the invention (5), the elastic block 21 is formed with a through hole 22, which communicates with the connection pad 2 and is filled with the conductive material 23, and the conductive material 23 is filled in the through hole 22 and Extending ^ On the top surface of the elastic block 21, the conductive material 23 in the through hole 22 is nickel [η], gold [Au] silver [Ag], copper [Cu], Ibar [Pd], tin tin [SkPb alloy ], Silver gel or anisotropic conductive adhesive, if necessary, another conductive material 24 can be formed on the top surface of the elastic block 21, which contains nickel, gold, silver, and copper. , Palladium or tin-lead composite metal layer [c0mp〇site layers], or nickel, gold, silver, copper, palladium, tin-lead, silver paste or conductive paste, according to the needs of the process, conductive in the through hole 22 The material 23 and the conductive material 24 on the top surface of the elastic block 21 may be the same or different materials. Due to the good elasticity of the elastic block 21 and the good bendability of the thin linear conductive material 23, the above-mentioned The elastic bump 20 has good robustness, so the electronic device having the elastic bump 20 can be surface-bonded to a non-complete plane. That is, even if the external circuit board has a non-substantially flat hard surface, such as a flexible board or a printed circuit board with an irregular level, the electronic device with the elastic bump 20 can also achieve a good quality with it. The electrical bonding, and after the surface of the electronic device is bonded to the external circuit board, the elastic bumps 20 can absorb the stress of the bonding interface of the electronic device and have the flexibility of the bumps to increase the filling of the filling material [uncjer fi 1 1 i ng] step. The method of forming an elastic bump on an electronic device according to the present invention is as follows:. As shown in FIGS. 2a and 3, a substrate 10, such as a wafer, a wafer, a printed circuit board, a ceramic substrate, or a thin film, is provided on the surface of the substrate.

1237858 V. Description of the invention (6) " A plurality of connection pads 12, preferably, the connection pads 2 are in a grid-like array, or they may be arranged in a straight line or a periphery. After that, as shown in FIG. 2b and FIG. 4, an electrically insulating elastic layer 25 is formed on the surface of the substrate by printing, spin coating, or film adhering techniques. It covers the connection pads 12. Necessarily, after the elastic layer 25 is formed, the surface of the plate 10 (that is, the corresponding surface of the above-mentioned surface 11) is appropriately polished. Since the connection pads have been covered by the elastic layer 25, It can avoid staining the connection pads 2 during grinding. Afterwards, as shown in FIGS. 2c and 5, the elastic layer 25 is etched by using lithography [Phenol i thograthy] and dry / wet etching techniques to form elastic blocks 21 provided on the connection pads 12. The elastic blocks 21 The cover covers the corresponding connection pad 12 and is formed with at least one through hole 22, which is connected to the corresponding connection pad 12.

Afterwards, as shown in Fig. 2d, the method of forming a conductive material 2 3 and the material 2 3 are thin lines, so it has a good shape as shown in Fig. 2 e, and the top surface of the electrodeless block 21 is formed. A conductive material 24 is used to cut the substrate 10 to obtain a device. The deep-hole electric shovel, printing or capillary is used to fill the above-mentioned through-holes 22, and the conductive holes 22 have good toughness and extensibility. Preferably, the electric clock, printing or sticking method is elastic to improve the bonding of welding. For the most of the above-mentioned electronic device with elastic bumps 20, and the electronic device with elastic bumps according to the present invention, the elastic block is not limited to a single through hole. As shown in FIG. 6, in another specific embodiment, the The electronic device with elastic bumps includes a substrate 30 and a plurality of 1237858 on the substrate 30. V. Description of the invention (7) Elastic bumps 40. In this embodiment, the substrate 30 is a printed circuit board having The conductive lines 33 formed on the multilayer circuit layer and the solder resist layers 34 on the upper and lower surfaces, among which the solder resist layer 34 on one surface 31 exposes the connection pads 32, and the elastic bumps 40 Then, the connecting pads 32 are formed. Each of the elastic bumps 40 has an electrically insulating elastic block 41 and a conductive material 4 3 and 44. The elastic block 41 is cylindrical and is formed with a plurality of through holes 42. To form a plurality of thin linear conductive materials 43 on top of the elastic block 41 The other is formed with a conductive material 44, for surface engagement, so that the resilient bumps 4 square itself i.e. have good of elasticity, having preferably in thermal stress absorption, and showed an engaging effect external circuit board insubstantial plane. 〃 Therefore, the scope of protection of the present invention shall be subject to the applicants attached. Any changes and modifications made by anyone who is familiar with this technology, Mosewei, are within the scope of this invention without departing from the invention. ， 红 化 劫 i λ ^ 社 社 社 心. G% w Dan rjie the spirit of the moon and the protection range 1237858 Schematic illustration [Schematic description] Figure 1: According to the present invention, the size of the package structure 2a to 2e 丨 Figure •• According to the present invention, the method 1 is formed in the cross-sectional schematic diagram 9 Figure 3: According to the present invention in the method 5 provided by the fourth figure: according to the present method of the present invention, Figure 5 with elasticity: Method 5 according to the invention according to the invention Figure 6: Elastic electronic device with elastic bumps according to the invention according to the invention, a schematic cross-sectional view of a crystal; elasticity is formed on the electronic device In the process of some elastic bumps of the bumps, the forward direction of the plate forming the elastic bumps on the electronic device of the substrate is not intended. Forward of the substrate layers schematic bumps; forward block schematic diagram of the substrate of elastomeric bumps formed on an electronic device; and an electronic device the resilient bumps, a cross-sectional schematic view of another sub-unit. [Illustration of drawing number] 10 substrate 11 surface 12 connection pad 20 elastic bump 21 elastic block 22 through hole 23 conductive material 24 conductive material 25 elastic layer 30 substrate 31 surface 32 connection pad 33 conductive line 34 solder resist layer 40 elastic bump 41 Elastic block 42 Through hole 43 Conductive material 44 Conductive material

Claims (1)

1237858 6. Scope of patent application, an electronic device with elastic bumps, comprising: a substrate having a plurality of connection pads on one surface thereof; and a plurality of elastic bumps formed on the connection pads, each of the elastic bumps An elastic block and a conductive material having electrical insulation are formed in the elastic block. The elastic block is formed with at least one through hole that communicates with the corresponding connection pad. The conductive material is filled in the through hole and extends to the top surface of the elastic block. 2. The electronic device with elastic bumps as described in item 1 of the patent scope of Shenyan, wherein the elastic block is a polymer organic substance. Electronic equipment with elastic bumps as described in item 1 of the scope of patent application Wherein the elastic block is selected from the group consisting of polyimide, phenylcyclobutene, polyacrylate, rubber, and silicone. The electronic device with elastic bumps described in Item 1 of the scope of the patent claims, wherein the elastic blocks cover the corresponding connection pads. The electronic device with elastic bumps as described in item 1 of the scope of the patent application. [, The substrate is a wafer, wafer, printed circuit board, ceramic substrate or film. According to the electronic device with elastic bumps described in item 1 of the scope of patent application, the conductive material in the through hole is nickel, gold, silver, steel, tin lead, silver glue or anisotropic conductive glue. Set silver The electronic device with elastic bumps as described in item i of the scope of the application, wherein the conductive material on the top surface of the elastic block is a composite metal layer containing nickel, gold, copper, copper or tin. Electricity with elastic bumps as described in the patent application ㈣1 帛, where the conductive material on the top surface of the elastic block is nickel, gold, silver Page 13 1237858 6. Scope of patent application Copper, palladium, tin-lead, silver glue or anisotropic conductive glue. 9. A method for forming elastic bumps on an electronic device, comprising the steps of: providing a substrate having a plurality of connection pads on one surface; forming an electrically insulating elastic layer on the surface of the substrate to cover the connection pads; _ Engraving the elastic layer to form elastic blocks provided on the connection pads, the elastic blocks are formed with at least one through hole, which is connected to the corresponding connection pads; and U forms a conductive material in the through holes. Figure 10. The method for forming elastic bumps on an electronic device as described in item 9 of the scope of the patent application, further comprising the steps of: forming a conductive material on the top surfaces of the elastic blocks. 11. The method for forming an elastic bump on an electronic device as described in item 9 of the scope of the patent application, wherein the method of forming the electrically insulating elastic layer is printing, spin coating or adhesive film sticking. 1 2. The method of forming elastic bumps on an electronic device as described in item 9 of the scope of the patent application, wherein the method of forming the conductive material is an electroplating brush. 1 1 3. The method for forming elastic bumps on an electronic device as described in item 9 of the scope of the patent application, wherein the substrate provided is a wafer, a printed circuit board, a ceramic substrate or a thin film. 1 4. The method for forming elastic bumps on an electronic device as described in item 9 of the scope of patent application, after forming the electrically insulating elastic layer, the additional package is I237858 ^ -__ 15 Includes: grinding the other surface of the substrate. A chip-size package structure comprising a chip having an active surface with a plurality of connection pads; and 16 17 18 19 20 21 a plurality of elastic bumps formed on the connection pads, each of which has a An electrically insulating elastic block and a conductive material. The elastic block is formed with at least one through hole that communicates with a corresponding connection pad, and a conductive material is filled in the through hole and extends to a top surface of the elastic block. “” The chip size package structure described in item 15 of the scope of patent application, wherein the elastic block is a polymer organic substance. The chip size package structure described in item 15 of the scope of patent application, wherein the elastic block is selected from Polyimide, phenylcyclobutene, polyisocyanate, rubber, and silicone. For a long time, the chip-size package described in item 5 of the patent application scope has these elastic blocks covering the corresponding connection pads. The chip size package according to item 15 of the scope of the patent application, wherein the conductive material in the through hole is nickel, gold, silver, steel, tin, silver glue or anisotropic conductive glue. The chip size package described in item 15 of the patent scope, wherein the conductive material on the top surface of the elastic block is a composite metal layer containing nickel, gold, copper, palladium, or tin-lead. The chip size package according to item 5, wherein the conductive material on the top surface of the elastic block is nickel, gold, silver, sigma, tin tin, silver glue or anisotropic conductive glue. 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