DVD-R bonding process problem highlights four

As CD-R develops to 48X/52X high-speed recording speed, DVD-R will also enter 8X recording at the end of the year, warpage of the disc, uniformity of thickness, internal and external reproduction rate of grooves, variation of dye thickness on the inner and outer diameters. The impact on the recording speed will increase, and the most important factor is still warping.

Because the DVD9 bonding surface will affect the reading of the two recording layers, and the DVDR adhesive surface thickness and uniformity requirements are not as strict as the DVD9, so I recommend that the process should be used to make the DVDR heavier and thicker side of the process, because The general UV light irradiation is only done on one side, so the heat and adhesive thickness of the top half Dummy are less affected by the change of the inside and outside thickness of the bonding surface, so the weight of the information half surface and the inside and the middle of the eight radiation directions The thickness of the outer and outer points should be confirmed by a disc thickness meter, and the mechanical parallelism and injection parameters in the injection molding machine should be adjusted to a stable condition to avoid the rotation imbalance due to the offset of the center of mass ( Disc Unbalance). This leads to a slowdown in reading and writing.

Conclusion: The production rate for producing DVDR "Practice in Individuals"

The influence of printing on the warpage of the finished product is often neglected in the production plant. We should understand the film structure and process of DVDR, record the status of each layer separately, and then make a difference analysis with the characteristics of the finished product.

(1) The structure of the laser reading head of each recorder manufacturer is not the same, and sometimes the accuracy of some disc signals must be sacrificed in exchange for compatibility with various recorders.

(2) The half-injection flatness and weight of the information piece need to be high, and empirically, the weight 0.598g will be more severe than the 0.601 g warpage. Birefringence should also be kept within the allowable range so that the laser cannot be effectively focused.

(3) The photosensitivity, thermal conductivity, and thickness of the dye determine the recording speed.

(4) The thickness of silver is appropriate, and if it is too thick, it will result in a waste of cost. Raising the power due to the consumption of sputtering targets can also affect warpage.

(5) Some off-line production will be covered with a layer of protective glue to block the chemical reaction between silver and adhesive, but it also increases the warpage problem.

(6) The uniformity of the adhesive layer is determined by the rotational acceleration. The lifetime of UV curing lamps is also the focus that manufacturers often ignore.

(7) The thickness, weight and warpage of the Dummy half piece are related.

(8) The adhesion of printed inks and the number of printed colors are also important.

Each factory's injection molding, copying lines, printing presses and other equipment are not the same, for example, plastic brand, die groove, mold temperature setting, cooling time, dye concentration, sputtering power, bonding, light curing symmetry The combination of raw materials and processes such as printing inks, etc., all require the accumulation of trial and experience of process engineers to achieve the best match to produce a DVDR optical disc with stable quality. 03-5

(Author: Decca Engineering Co., Ltd. Chen thick mold)

From: "Recording Media Technology"