Ball grid array package

Abstract

The embodiment relates to a ball grid array package. A ball grid array package according to one aspect includes: a substrate; an IC chip disposed on the substrate; a ball electrically connecting the substrate and the IC chip; and a reinforcing portion provided on the IC chip.

Description

Technical Field

[0001] This embodiment relates to a ball grid array package. Background Art

[0002] After completing the manufacturing process of semiconductor devices, a packaging process for semiconductor devices is performed, and the process sequence includes the following steps: inspecting a wafer; mounting the wafer, where the wafer is attached to an adhesive film; sawing, where the wafer made of multiple chips is cut to separate each chip; die bonding, where the die is attached to a lead frame on a packaging substrate using an adhesive material, wire bonding is performed on the pads of the die and the leads of the package using conductive metal wires, and the periphery of the chip is coated with a protective material and bonded; and lead forming, where the leads are formed in a form that can be mounted on a PCB, and the packaging process is completed through steps of marking, lead finishing, inspection, and testing.

[0003] In a ball grid array package, underfill is required to improve the thermal reliability of the balls. In this process, if the underfill filler is not uniformly applied to the substrate surface, there is a risk of short circuit between multiple balls due to void phenomena in the unfilled portions of the underfill on the substrate surface. Prior Art Documents Patent Document (Patent Document 1) Korean Patent Publication No. 10-1489469 (published on February 5, 2015) Summary of the Invention

Technical Subject

[0004] The present invention is proposed to improve the above problems and aims to provide a ball grid array package that can improve production efficiency and prevent ball short circuits by omitting underfill.

Technical Solution

[0005] The ball grid array package according to this embodiment includes: a substrate; an IC chip disposed on the substrate; balls electrically connecting the substrate and the IC chip; and a reinforcing part disposed on the IC chip.

Advantageous Effects

[0006] Through this embodiment, since the thermal expansion coefficient of the bonding material is formed to be the same as or similar to the thermal expansion coefficients of the substrate and the balls, and since all components in the package contract and expand in the same or similar manner according to temperature changes, there is an advantage of preventing cracks in the balls.

[0007] In addition, since the underfill process between the IC chip and the substrate can also be omitted, there is an advantage of improving production efficiency due to the reduction of assembly man-hours. Brief Description of the Drawings

[0008] Figure 1A cross-sectional view of a ball grid array package according to an embodiment of the present invention.

[0009] Figure 2 A diagram for explaining physical property changes caused by the combination of a reinforcing part and an IC chip in a ball grid array package according to an embodiment of the present invention.

[0010] Figure 3 Experimental data obtained by experimentally photographing the state of balls in a ball grid array package according to an embodiment of the present invention and a ball grid array package according to a comparative example. Detailed Description of the Invention

[0011] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0012] However, the technical idea of the present invention is not limited to some embodiments to be described, but can be implemented in various forms, and within the scope of the technical idea of the present invention, one or more of the constituent elements can be selectively combined or replaced between embodiments.

[0013] In addition, unless clearly defined and described, terms (including technical terms and scientific terms) used in the embodiments of the present invention can be interpreted as meanings that can be generally understood by those skilled in the art, and terms commonly used such as terms defined in a dictionary can be interpreted in consideration of the meaning of the context of the related art.

[0014] In addition, the terms used in this specification are for describing embodiments and are not intended to limit the present invention.

[0015] In this specification, unless specifically stated in a phrase, the singular form may include the plural form, and when described as "at least one (or more than one) of A, B, and C", it may include all combinations in which one or more can be combined with A, B, and C.

[0016] In addition, when describing components of embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only intended to distinguish components from other components, and these terms do not limit the nature, order, or sequence of the components.

[0017] Furthermore, when a component is described as "connected", "coupled", or "interconnected" to another component, the component is not only directly connected, coupled, or interconnected to the other component, but may also include cases where it is "connected", "coupled", or "interconnected" because of other components between the other components.

[0018] In addition, when described as being formed or disposed “on (above)” or “under (below)” each component, “on (above)” or “under (below)” means not only including the case where two components are in direct contact, but also including the case where one or more other components are formed or disposed between the two components. In addition, when expressed as “on (above)” or “under (below)”, it can include not only the meaning of the upward direction with respect to one component, but also the meaning of the downward direction with respect to one component.

[0019] Figure 1 is a cross-sectional view of a ball grid array package according to an embodiment of the present invention; Figure 2 is a diagram for explaining changes in physical properties due to the combination of a reinforcing part and an IC chip in a ball grid array package according to an embodiment of the present invention; and Figure 3 is experimental data obtained by photographing the state of balls through experiments in a ball grid array package according to an embodiment of the present invention and a ball grid array package according to a comparative example.

[0020] Reference Figure 1 and Figure 2 According to FIGS. 1 and 2, a ball grid array package 10 according to an embodiment of the present invention may include a substrate 100, an IC chip 200, balls 300, and a reinforcing part 400.

[0021] The substrate 100 may be formed in a plate shape. Circuit patterns 110 may be formed on the surface of the substrate 100 for electrical and physical bonding with the balls 300. The circuit patterns 110 may be referred to as terminals. The circuit patterns 110 may be provided in plurality and spaced apart from each other on the surface of the substrate 100. The material of the circuit patterns 110 may be copper (Cu).

[0022] The coefficient of thermal expansion (CTE) of the substrate 100 may be 17 ppm / °C or more and 19 ppm / °C or less. As an example, the coefficient of thermal expansion of the substrate 100 may be 18 ppm / °C.

[0023] The IC chip 200 may be disposed on one surface of the substrate 100. The IC chip 200 may be disposed on the upper surface of the substrate 100. The IC chip 200 may be bonded to the upper surface of the substrate 100. The IC chip 200 may be mounted on the substrate 100. The IC chip 200 may be mounted on the substrate 100 using a ball grid array (BGA) method.

[0024] The IC chip 200 may be made of resin or plastic.

[0025] The IC chip 200 may have a coefficient of thermal expansion lower than that of the substrate 100. The coefficient of thermal expansion of the IC chip 200 may be 4 ppm / °C or greater and 6 ppm / °C or less. As an example, the coefficient of thermal expansion of the IC chip 200 may be 5 ppm / °C.

[0026] The IC chip 200 may have a rectangular cross-sectional shape.

[0027] The ball 300 may be a solder ball. The ball 300 may have a circular or elliptical cross-sectional shape. The IC chip 200 and the substrate 100 may be electrically and physically bonded through the ball 300. The ball 300 may be in contact with the metal region of the IC chip 200 and the circuit pattern 110 of the substrate 100, respectively. The ball 300 is melted through a reflow process to electrically connect the IC chip 200 and the substrate 100 between the IC chip 200 and the substrate 100.

[0028] A plurality of balls 300 may be provided and arranged to be spaced apart from each other in a horizontal direction perpendicular to the vertical direction between the IC chip 200 and the substrate 100.

[0029] The coefficient of thermal expansion of the ball 300 may be 19 ppm / °C or greater and 21 ppm / °C or less. For example, the coefficient of thermal expansion of the ball 300 may be 20 ppm / °C. The coefficient of thermal expansion of the circuit pattern 110 may be the same as that of the ball 300.

[0030] The reinforcing portion 400 may be provided on the upper surface of the IC chip 200. The reinforcing portion 400 may have a plate shape. The reinforcing portion 400 may be made of metal. The reinforcing portion 400 may be a metal plate. The material of the reinforcing portion 400 may include stainless steel (SUS) and aluminum (Al).

[0031] Alternatively, the material of the reinforcing portion 400 may be resin or plastic. As an example, the material of the reinforcing portion 400 may be epoxy molding compound (EMC).

[0032] The cross-sectional area of the reinforcing portion 400 may be larger than the cross-sectional area of the IC chip 200. The thickness of the reinforcing portion 400 may be greater than the thickness of the IC chip 200. Alternatively, the thickness of the reinforcing portion 400 may be thinner than the thickness of the IC chip 200. The thickness of the reinforcing portion 400 may be 0.2 mm or greater and 0.6 mm or less. When the thickness of the reinforcing portion 400 exceeds 0.6 mm, there is a problem of reduced bonding strength with the IC chip 200. When the thickness of the reinforcing portion 400 is less than 0.2 mm, bonding with the IC chip 200 may not cause a change in physical properties, which will be described later.

[0033] The reinforcing part 400 can be bonded to the IC chip 200 using an adhesive 500. The adhesive 500 can include an epoxy resin. The adhesive 500 can be applied to at least one of the lower surface of the reinforcing part 400 or the upper surface of the IC chip 200 to bond the reinforcing part 400 and the IC chip 200 to each other.

[0034] The coefficient of thermal expansion of the reinforcing part 400 can be greater than that of the IC chip 200. When the bonded configuration of the reinforcing part 400 and the IC chip 200 is referred to as a bonded body, the coefficient of thermal expansion of the bonded body is greater than that of the IC chip 200, and the thermal expansion of the reinforcing part 400 can be less than this coefficient.

[0035] The coefficient of thermal expansion of the bonded body can be 10 ppm / °C or greater and 20 ppm / °C or less.

[0036] The difference between the coefficient of thermal expansion of the bonded body and that of the substrate 100 or the difference between the coefficient of thermal expansion of the bonded body and that of the ball 300 can be 10 ppm / °C or less.

[0037] When the reinforcing part 400 having a relatively high coefficient of thermal expansion is bonded to the IC chip 200, the low coefficient of thermal expansion of the IC chip 200 can be compensated for by the bonded body. That is, as Figure 2 shown, even if tensile stress is generated in the IC chip 200 due to heat generation during the reflow process, compressive stress may be generated in the reinforcing part 400 having a high coefficient of thermal expansion under the temperature conditions of the reflow process.

[0038] That is, since the coefficient of thermal expansion of the bonded body is formed to be the same as or similar to the coefficient of thermal expansion of the substrate 100 and the ball 300 according to the ball grid array package 10 of the present embodiment, and since all components in the package contract and expand in the same or similar manner according to temperature changes, there is an advantage of preventing cracks in the ball 300.

[0039] Accordingly, it is also possible to omit the underfill process between the IC chip 200 and the substrate 100, and thus there is an advantage of improving production efficiency due to a reduction in assembly man-hours.

[0040] Referring to Figure 3 , it can be confirmed that cracks occur under various conditions due to thermal shock in the case of the ball in the comparative example where the reinforcing part 400 is not applied, but it can be confirmed that the ball grid array package 10 according to the present embodiment to which the reinforcing part 400 is applied does not generate cracks under various conditions of thermal shock.

[0041] In the above description, all components constituting the embodiments of the present invention are combined or operated in one, but the present invention is not necessarily limited to these embodiments. In other words, within the scope of the present invention, all components can be selectively combined and operated with one or more. Additionally, the terms "comprising", "including", or "having" described above indicate that the corresponding components may be inherent, unless otherwise specifically stated, and thus should be construed as not excluding other components, but further including other components. Unless otherwise defined, all terms, including technical terms and scientific terms, have the same meaning as commonly understood by those of ordinary skill in the art. Commonly used terms (such as those defined in a dictionary) should be construed as consistent with the context meaning of the relevant technology, and should not be construed in an ideal or overly formal sense unless explicitly defined in the present invention.

[0042] The above description is only an illustration of the technical idea of the present invention, and those skilled in the art to which the present invention pertains can make various modifications and changes without departing from the essential features of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be construed as being included within the scope of the present invention.

Claims

1. A ball grid array package, comprising: substrate; An IC chip is disposed on the substrate; a ball electrically connecting the substrate and the IC chip; as well as The reinforcing portion is arranged on the IC chip.

2. The ball grid array package according to claim 1, in, The reinforcement portion is a metal plate.

3. The ball grid array package according to claim 1, in, The reinforcing part is made of resin or plastic.

4. The ball grid array package according to claim 1, in, The thermal expansion coefficient of the reinforcing portion is greater than the thermal expansion coefficient of the IC chip.

5. The ball grid array package according to claim 1, in, A combination is formed by combining the IC chip and the reinforcing portion, The difference between the thermal expansion coefficient of the combination and the thermal expansion coefficient of the substrate or the difference between the thermal expansion coefficient of the combination and the thermal expansion coefficient of the ball is 10 ppm / °C or less.

6. The ball grid array package according to claim 1, comprising: An adhesive bonds the IC chip and the reinforcing portion.

7. The ball grid array package according to claim 6, in, The adhesive includes epoxy resin.

8. The ball grid array package according to claim 1, in, The cross-sectional area of ​​the reinforcing portion is larger than the cross-sectional area of ​​the IC chip.

9. The ball grid array package according to claim 1, in, The thickness of the reinforcing portion is greater than the thickness of the IC chip.

10. The ball grid array package according to claim 1, comprising: a circuit pattern formed on the substrate to be combined with the ball, Wherein, the thermal expansion coefficient of the circuit pattern is equal to the thermal expansion coefficient of the ball.

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