KR20030077777A - Black ink coating layer composition for laser marking of tape ball grid array package - Google Patents

Abstract

PURPOSE: A black ink coating layer composition for laser marking of a tape ball grid array package(TBGA) is provided to be capable of improving marking performance of the laser marking process. CONSTITUTION: A TBGA package is provided with a metal heat spreader(1), a ground plate having a cavity, attached on the upper portion of the heat spreader, and a semiconductor chip attached to the heat spreader in the cavity of the ground plate. A black ink coating layer(22) is formed at the upper portion of the heat spreader for improving marking performance. At this time, the black ink coating layer is made of a black ink coating composition containing bisphenol A type epoxy resin of 15-20 wt%, teflon of 5-10 wt%, titanium oxide of 9-10 wt%, amine of 8-10 wt% as a hardener, and carbon black of 2-3 wt%.

Description

Black ink coating layer composition for laser marking of tape ball grid array package {BLACK INK COATING LAYER COMPOSITION FOR LASER MARKING OF TAPE BALL GRID ARRAY PACKAGE}

The present invention relates to a marking process of a tape ball grid array (Tape Ball Grid Array) package, and more particularly, to an optimal black ink coating layer composition capable of improving the marking performance when applying a laser marking process.

In general, semiconductor chips manufactured through a series of semiconductor manufacturing processes are sent to an assembly process and packaged into individual products, and as the final order of the assembly process, the product name, management code on the surface of the package, that is, the upper and lower surfaces thereof, are packaged. And it goes through a marking process (Marking Process) for displaying a variety of information, such as the assembly date.

The marking process can be divided into ink marking by ink printing and laser marking by laser irradiation according to the process method. In the past, the ink marking method was mainly used. In consideration of the laser marking method is mainly used.

That is, the ink marking method can be easily performed and a relatively clear marking effect can be obtained, but defects in which the mark is erased during reliability testing or during use are generated, and in particular, environmental pollution is caused by the use of a chemical solution. It has the disadvantage of causing an increase in time and cost. On the other hand, the laser marking method does not have to worry that the mark is erased after marking, and in particular, since it does not need to undergo a curing process after marking, it has the advantage of improving productivity and quality.

Therefore, for this reason, most of the recent marking processes use a laser marking method.

However, despite the advantages of the laser marking method, there is a problem in that the marking performance, that is, the sharpness of the mark varies depending on the type and composition of the target layer to which the laser is irradiated. do.

In particular, in applying a laser marking method to a tape ball grid array (TBGA) package proposed by the present applicant, a thin nickel layer on the surface of a heat spreader made of copper is present. The laser is irradiated in the state of coating, but in this case, the sharpness of the mark is not good in relation to the laser irradiation target layer being a metal layer.

For reference, as shown in FIG. 1, the TBGA package proposed by the applicant has silver plating (Ag Plating) 4 in place while having a cavity on a copper heat spreader 1. A polyimide having a ground plate (2) formed thereon, a semiconductor chip (3) attached to a heat spreader portion in the cavity, and a copper wiring (6) and a solder mask (7) formed on the ground plate (2). A tape 5 is attached, the semiconductor chip 3 and the copper wiring 6 are wire bonded, an area including the semiconductor chip 3 and the gold wire 8 is sealed with an encapsulant 9, Then, the solder ball 10 is attached to the exposed copper wiring (6), the laser marking for this TBGA package is a thin nickel layer 11 on the surface of the heat spreader (1) exposed to the outside ) Is formed.

On the other hand, when the ink marking is applied to the TBGA package, the problem of the ink marking is basically shown, as well as additional marks due to the cleaning solution used in the reflow process for solder ball attachment and the cleaning process after flux removal. Damage is caused and marking performance is greatly reduced.

As a result, the marking process that can secure the marking performance for the TBGA package is not currently made.

Accordingly, an object of the present invention is to provide an optimum black ink coating layer composition capable of improving the marking performance in a laser marking process.

1 is a cross-sectional view of a proposed tape ball grid array package.

2 is a view for explaining a laser marking process of the tape ball grid array package according to the present invention.

Explanation of symbols on the main parts of the drawings

DESCRIPTION OF SYMBOLS 1: Heat spreader 21: Copper black oxide layer

22: black ink coating layer 23: mark

The black ink coating layer composition for laser marking of the TBGA package of the present invention for achieving the above objects is a ground plate having a metal heat spreader and a cavity attached to the heat spreader and on the heat spreader portion in the cavity. In the black ink coating layer composition coated on the metal heat spreader to improve the marking performance in applying a laser marking process to a TBGA package including a semiconductor chip to be attached, a bisphenol A type epoxy resin 15 to 20 wt% of Teflon, 5 to 10 wt% of Teflon, 9 to 10 wt% of titanium oxide, 8 to 10 wt% of amine as a curing agent, and 2 to 3 wt% of carbon black. do.

According to the present invention, the marking performance can be improved by setting an optimal black ink coating layer composition in applying the laser marking process for the TBGA package, and it is possible to secure the reliability of the laser marking process for the TBGA package.

(Example)

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a view for explaining a laser marking process of the TBGA package according to the present invention.

As shown, the laser marking process of the present invention is different from the conventional laser marking process in which a nickel layer of a thin film for oxidation prevention is coated on a copper heat spreader and then the laser is irradiated to the nickel layer. After the black ink coating layer 22 is formed on the spreader 1, the black ink coating layer 22 is irradiated with a laser to perform laser marking 23. Reference numeral 21 denotes a copper black oxide layer formed on the surface of the heat spreader 1 made of copper.

In detail, in the present invention, in applying a laser marking process to a TBGA package, first, to increase the marking performance on a copper heat spreader 1 having a copper black oxide layer 21 formed on a surface thereof as it is exposed to the outside of the package. To form a black ink coating layer 22 to a thickness of 0.015 to 0.017 mm, preferably 0.016 mm, and then irradiate the YGA laser to the black ink coating layer 22 to a depth of approximately 0.004 to 0.010 mm. 23).

Here, commonly used black ink contains 35 to 65 wt% solvent, 20 to 30 wt% epoxy resin, 3 to 5 wt% carbon black, and other components, which are subjected to laser irradiation to form a mark. In this case, the initial mark clarity is good, but as applied to the TBGA package, the mark damage is caused by the cleaning solution used in the subsequent process, e.g. reflow process for solder ball attachment, and the cleaning process after flux removal. In the conventional black ink, marking performance in a TBGA package cannot be secured.

Therefore, in the present invention, in applying a laser marking process to a TBGA package, the composition of the black ink coating layer coated on the heat spreader to secure marking performance is 5 to 20 wt% of bisphenol A type epoxy resin. %, 5-10 wt% of Teflon, 9-10 wt% of titanium oxide, 8-10 wt% of amine (Amin) as a curing agent, and 2-3 wt% of carbon black, In order to find the optimal composition of the black ink coating layer, the following experiment was performed.

Table 1 below shows the procedure of the experiment.

Table 1

fair Condition Considerations Die / attach hardening 175 ± 5 ℃ / 15min Did the coating react? plasma 300 W / 200 seconds Did the coating react? Wire bonding W / B heating (150 ℃ / 2 minutes) Did the coating react? Encapsulant Curing 125 ℃ / 30min & 165 ℃ / 90min Did the coating react? Mark Laser marking Visual inspection Solder Ball Mount Reflow 183 ° C / 40 seconds Did the marking color change? Cleaning Did the coating react with the flux? Bake 135 ℃ / 6 hours Did the marking color change?

[Experiment 1]

Tables 2 and 3 below show the marking performance according to the base material composition and fluorine content of the black ink coating layer when the fluorine component ratio is changed.

Table 2

Component Content Epoxy Resin, Bisphenol A type 15 to 20 wt% Carbon black 2-3 wt% P.T.F.E Fluorine Solvent 10-13 wt% n-butyl alcohol 10-13 wt% diaceton alcohol 10-13 wt% methyl isobutyl keton 15 to 20 wt% xyl 10-15 wt% Solvent A Less than 3wt%

Table 3

Fluorine content test mode 0wt% 5wt% 10wt% 15 wt% Chemical resistance lowness height height height Marking performance Not good Not good Not good Not good Color change after baking No test required

As a result of Experiment 1, it was found that the coating layer component was dissolved in the flux solution, the marking color became unclear, and the P.T.F.E (Poly Tetra Fluorine Ethylene) component was not related to the marking color.

[Experiment 2]

Tables 4 and 5 below show the base material composition of the black ink coating layer and the marking performance according to the new component when a new component is added.

Table 4

Component Content Epoxy Resin, Bisphenol A 15 to 20 wt% Carbon black 2-3 wt% Solvent n-butyl alcohol 7-10 wt% diaceton alcohol 7-10 wt% methyl isobutyl keton 10-15 wt% xyl 7-10 wt% Solvent A Less than 3wt%

Table 5

New ingredient test mode SilkPolyethylene Resin Grade A, 20 ~ 30wt% PoltoPolyethylene Resin Grade B, 20 ~ 30wt% PropylPolyethylene20-30wt% MSP siloxane 20-30 wt% Chemical resistance height height height height Marking performance Not good Color change after baking No test required

As a result of Experiment 2, the chemical resistance was excellent, but the marking color was unclear, and the result of the laser marking performance improvement was not great.

[Experiment 3]

Tables 6 and 7 below show a marking performance according to the basic material composition of the black ink coating layer and the type of carbon black when a phenol hardener is used and the type of carbon black is changed.

Table 6

Component Content Epoxy Resin, Bisphenol A 15 to 20 wt% Carbon black 2-3 wt% Hardener, Phenol 3-5 wt% Solvent n-butyl alcohol 10-13 wt% diaceton alcohol 10-13 wt% methyl isobutyl keton 15 to 20 wt% xyl 10-15 wt% Solvent A Less than 3wt%

Table 7

Carbon Black Test Mode 111 211 116 411 Chemical resistance height height height height Marking Reliability Not good Not good Not good Not good Color change after baking No test required

In Table 7, 111 is Denka Black, 211 is Furnace Natural Glass Vulcane Carbon Black, 116 is Furnace Petroleum Carbon Black, and 411 denotes Channel Type Carbon Balck, respectively.

As a result of Experiment 3, when the phenol hardener (Penol Hardener) was used and the type of carbon black was changed, the chemical resistance was excellent as in the Experiment 2, but the marking color was unclear. In addition, it was found that special additives are needed to improve the laser marking performance.

[Experiment 4]

Tables 8 and 9 below show the basic material composition and additives of the black ink coating layer when Teflon, Titanium Oxide, and amine or phenol (Amin or Phenol) were added as a hardener. Marking performance is shown.

Table 8

Component Content Epoxy Resin, Bisphenol A 15 to 20 wt% Carbon black 2-3 wt% Solvent n-butyl alcohol 7-10 wt% diaceton alcohol 7-10 wt% methyl isobutyl keton 10-15 wt% xyl 7-10 wt% Solvent A Less than 3wt%

Table 9

Type Component / Test Mode Type A Type B Type C Type D Type E Teflon 5-10wt% 55-10 wt% 5-10wt% × 5-10wt% Titanium oxide 10wt% 15 wt% 20wt% 10wt% 10wt% Hardener (3-5%) Amine Amine Amine Amine phenol Chemical resistance height height height height height Marking performance Marginal performance Not good Not good Not good Marginal performance Marking color White Unreadable Dark yellow

As a result of Experiment 4, the chemical resistance was good as a whole, in particular, type A and E had a relatively good marking performance. In addition, it was found that the content of epoxy and Teflon was an important factor for laser marking, titanium oxide was associated with white marking, and phenolic type curing agent was associated with yellow-based marking.

[Experiment 5]

Table 10 and Table 11 below show the marking performance according to the base material composition and additives of the black ink coating layer in the case where an appropriate ratio of titanium oxide and amine and phenol as the curing agent were added to the base material composition of Experiment 4.

Table 10

Component Content Epoxy Resin, Bisphenol A 15 to 20 wt% Carbon black 2-3 wt% Solvent n-butyl alcohol 7-10 wt% diaceton alcohol 7-10 wt% methyl isobutyl keton 10-15 wt% xyl 7-10 wt% Solvent A Less than 3wt%

Table 11

Type Component / Test Mode Type F Type G Type H Type I Teflon 5-10wt% 55-10 wt% 5-10wt% 5-10wt% Titanium oxide 10wt% 15v% 20wt% 10wt% Curing agent (amine: phenol) 7: 3 3: 7 10: 0 5: 5 Chemical resistance height height height height Marking performance Marginal performance Good Marginal performance Good Marking color White White Gray Gray After baking color Gray

As a result of Experiment 5, when a hardening agent of titanium oxide, amine and phenol was added, excellent chemical resistance was obtained, and in particular, excellent marking performance was obtained. In addition, it was observed that the marking color changed to gray after baking.

As a result of the above experiments 1 to 5, in order to maximize the performance of laser marking on the TBGA package, the composition of the black ink coating layer should include bisphenol A type epoxy resin, teflon, titanium oxide, amine curing agent, and carbon black.

Therefore, the present invention is intended to contain 5 to 20% of bisphenol A type epoxy resin and 5 to 10% of Teflon which can increase chemical and thermal resistance. Improved marking performance during the laser marking process for TBGA packages by containing 9-10% titanium oxide, 8-10 wt% amine as a curing agent, and 2-3 wt% carbon black. .

As described above, the present invention can improve the marking performance against thermal, chemical and mechanical external environments by optimizing the composition of the black ink coating layer coated on the surface of the heat spreader when performing laser marking on the TBGA package. In addition, the reliability of the laser marking process for the TGBA package can be secured, and furthermore, the product reliability can be secured.

In addition, this invention can be implemented in various changes within the range which does not deviate from the summary.

Claims (1)

A laser marking process is applied to a tape ball grid array package comprising a metal heat spreader, a ground plate having a cavity attached to the heat spreader, and a semiconductor chip attached to the heat spreader portion within the cavity. In the black ink coating layer composition coated on the metal heat spreader to improve the marking performance in the application, It contains 15-20 wt% of bisphenol A type epoxy resin, 5-10 wt% of teflon, 9-10 wt% of titanium oxide, 8-10 wt% of amine as a curing agent, and carbon A black ink coating layer composition for laser marking of a tape ball grid array package, comprising 2-3 wt% of black.