Silicone resin pad having excellent uniformity

Abstract

Provided is a silicone resin pad manufactured by curing a liquid silicone resin comprising dimethyl siloxane and methyl vinyl siloxane, wherein, after curing, the silicone resin pad has an elongation (%) in the range of 400-500, a permanent compression set (%) of 0.5-0.6, a weight average molecular weight (g / mol) of 40,000-60,000, and a number average molecular weight (g / mol) of 1000-2000, whereby the silicone resin pad has uniformity with deformation within 70 μm when pressed at 90 kgf / cm2 over a length of 50 cm or greater.

Description

Silicone resin pad with excellent uniformity

[0001] The present invention relates to a silicone resin pad having excellent uniformity, and more particularly, to a silicone resin pad having excellent uniformity that can be mounted by pressing with excellent uniformity when pressing an electronic device such as a semiconductor chip.

[0002] As semiconductor line widths continue to shrink, various packaging technologies are being developed. However, these packaging processes require the technology to stack chips in multiple layers, and this requires the use of rubber-based pads, such as silicone resin.

[0003] However, as these silicone rubber pads expand in size, they suffer from a problem of poor uniformity across the entire surface area when pressurized for mounting electronic components such as chips. Therefore, the development of a new silicone rubber pad that can address this issue is necessary.

[0004] Therefore, the problem to be solved by the present invention is to provide a silicone resin pad having excellent uniformity and a method for manufacturing the same.

[0005] In order to solve the above problem, the present invention provides a silicone resin pad manufactured by curing a liquid silicone resin containing dimethyl siloxane and methyl vinyl siloxane, wherein after curing, the silicone resin pad has an elongation (%) in a range of 400 to 500, a compression set (%) in a range of 0.5 to 0.6, a weight average molecular weight (g / mol) of the silicone resin pad is 40,000 to 60,000, and a number average molecular weight (g / mol) is 1000 to 2000, and thus, the silicone resin pad is characterized in that when pressurized at 90 kgf / cm2 for a length of 50 cm or more, the step uniformity is within 70 μm.

[0006] In one embodiment of the present invention, the silicone resin pad is a compression pad for semiconductor packaging.

[0007] In one embodiment of the present invention, the silicone resin pad has a size of 50 cm x 50 cm or more, the curing time of the silicone resin pad is 5 to 15 minutes, and the curing temperature at this time is 100 degrees Celsius.

[0008] The silicone pad according to the present invention can obtain excellent uniformity when pressurized according to a combination of elongation and permanent compression set, and can maintain uniformity consistently over a large area in particular.

[0009] Figures 1 to 4 show the results of compression tests of silicone pads.

[0010] Figures 5 to 7 are the results of measuring the uniformity of pads while simultaneously increasing the length and width from 10 cm to 50 cm and 100 cm in Examples 1 and 3, respectively.

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

[0012] Before describing the present invention in detail, it should be noted that the terms or words used in this specification should not be interpreted as being unconditionally limited to their usual or dictionary meanings, and the inventor of the present invention may appropriately define and use the concepts of various terms in order to describe his or her invention in the best possible manner.

[0013] Furthermore, it should be noted that these terms and words should be interpreted with meanings and concepts that are consistent with the technical idea of ​​the present invention.

[0014] That is, the terms used in this specification are only used to describe preferred embodiments of the present invention, and are not intended to specifically limit the contents of the present invention.

[0015] It should be noted that these terms are defined taking into account the various possibilities of the present invention.

[0016] Additionally, in this specification, a singular expression may include a plural expression unless the context clearly indicates a different meaning.

[0017] Also, it should be noted that even if similarly expressed in plural, it can contain singular meaning.

[0018] Throughout this specification, whenever a component is described as "including" another component, it may mean that the component may further include any other component, rather than excluding any other component, unless specifically stated otherwise.

[0019] In one embodiment of the present invention, it was found that the combination of the permanent compression set and elongation of the silicone rubber significantly affects the uniformity of the pad during compression.

[0020] The present invention is described in more detail through the following examples.

[0021] Example

[0022] In one embodiment of the present invention, liquid silicone rubber (LSR) was cured at a temperature of 100 degrees Celsius to a size of 100 x 100 cm and a thickness of 3 mm.

[0023] In the present invention, 50 to 60 parts by weight of methyl vinyl siloxane was cured for 5 minutes at 150°C in a curing mold in the presence of a platinum catalyst (5 parts by weight) relative to 100 parts by weight of dimethyl siloxane to produce a liquid silicone rubber.

[0024] As a comparative example, the silicone resin is LSR, a liquid silicone rubber resin made of dimethyl and methyl vinyl siloxane copolymers, but with different molecular weights.

[0025] To this end, 10 parts by weight of methyl vinyl siloxane (Comparative Example 1) and 100 parts by weight of methyl vinyl siloxane were used for 100 parts by weight of dimethyl siloxane, respectively, and the mixture was cured in a curing mold at 150°C for 5 minutes with a platinum catalyst (5 parts by weight) to produce a liquid silicone rubber (Comparative Example 2).

[0026] In addition, unlike this, the curing time was set to 20 minutes instead of 5 minutes, and curing was performed with 200 parts by weight of methyl vinyl siloxane for 100 parts by weight of dimethyl siloxane (Comparative Example 3).

[0027] The molecular weights of the examples and comparative examples are as follows.

[0028] Example Comparative Example 1 Comparative Example 2 Comparative Example 3 Number average molecular weight (g / mol) 1867156424531953 Weight average molecular weight (g / mol) 5102791301023365323

[0029] The above molecular weight measurement is a method using GPC, and the molecular weight and distribution are calculated by setting the baseline close to 0 or the lowest point as the end point. Referring to the above results, it can be seen that there is a large difference in the number average molecular weight between the examples and comparative examples.

[0030]

[0031] Experimental Example 1

[0032] In this experimental example, the elongation (% modulus) according to ASTM D412 die-C and the compression set according to ASTM D 395 method-B were compared.

[0033] Elongation (%) Permanent Compression Set (%) Example 4990.57 Comparative Example 12040.21 Comparative Example 24600.75 Comparative Example 32110.24

[0034] Figures 1 to 4 show the results of compression tests of the silicone pads of Examples 1 to 3, respectively.

[0035] In one embodiment of the present invention, the manufactured silicone sheet was pressed against a pressure sensitive paper with a metal plate at a force of 90 kgf / cm2.

[0036] Referring to Figures 1 to 4, it can be seen that excellent uniformity is achieved when the elongation is in the range of 400 to 500 and the permanent compression set is in the range of 0.5 to 0.6. Here, a higher color component means that the pressure was applied more strongly.

[0037] In the case of Comparative Example 2, where the elongation is similar to that of the embodiment, the permanent compression set exceeds 0.7, so it can be seen that the uniformity is poor. On the other hand, in the case of Comparative Example 3, where the permanent compression set is similar, the elongation is significantly greater than that of the silicone pad of the present invention, but in this case, the uniformity was not good compared to that of the present invention.

[0038] Accordingly, the elongation range of the silicone pad according to the present invention is 400 to 550%, and at the same time, the permanent compression set ratio is 0.5 to 0.65. If either of these two conditions is outside the range, it is difficult to obtain the desired uniformity (step difference within 70 μm) as described above.

[0039]

[0040] Experimental Example 2

[0041] The silicone pad having the above characteristics according to the present invention exhibits particularly excellent uniformity, particularly over a large area of ​​100 x 100 cm.

[0042] Figures 5 to 7 are the results of measuring the uniformity of pads with a force of 90 kgf / cm2 while simultaneously increasing the length and width from 10 cm to 50 cm and 100 cm in Examples 1 and 3, respectively.

[0043] Referring to Figures 5 to 7, it can be seen that the uniformity worsens in Comparative Examples 1 and 3 as the pad size increases. However, in the case of the present invention, it can be seen that the uniformity is maintained constant despite the increase in size. Therefore, the above results show that the silicone pad according to one embodiment of the present invention has a uniformity of a step difference of 70 μm or less in a length and width (i.e., size) of at least 50 cm or more. In addition, the curing time is also less than 5 minutes to 20 minutes, more preferably less than 5 minutes to 15 minutes.

[0044] Accordingly, the silicone resin pad according to the present invention has a weight average molecular weight of 40,000 to 60,000 in terms of molecular weight, and at the same time, a number average molecular weight of 2000 or less, preferably 1500 to 2000.

[0045] This molecular weight combination particularly influences the uniformity of pressurization over large areas (at least 50 cm ) of silicone pads, as evidenced by the experimental results above. This suggests that, for a given weight, the presence of longer chain length polymers (i.e., wider polymer distribution) is particularly advantageous for uniformity of large-area substrates during pressurization.

[0046]

[0047] The present invention is a silicone resin pad having excellent uniformity, and its industrial applicability is recognized.

Claims

1. A silicone resin pad manufactured by curing a liquid silicone resin containing dimethyl siloxane and methyl vinyl siloxane. After curing, the elongation (%) of the silicone resin pad is in the range of 400 to 500, and the permanent compression set (%) is 0.5 to 0.

6. The silicone resin pad has a weight average molecular weight (g / mol) of 40,000 to 60,000, a number average molecular weight (g / mol) of 1000 to 2000, and thus, the silicone resin pad is characterized in that the silicone resin pad has a uniformity of a step difference of less than 70 μm when pressurized at 90 kgf / cm2 for a length of 50 cm or more.

2. In paragraph 1, A silicone resin pad characterized in that the above silicone resin pad is a compression pad for semiconductor packaging.

3. In paragraph 2, A silicone resin pad characterized in that the above silicone resin pad has a size of 50 cm x 50 cm or more.

4. In paragraph 1, A silicone resin pad characterized in that the curing time of the above silicone resin pad is 5 to 15 minutes and the curing temperature is 100 degrees Celsius.

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