Improved method and apparatus for optically transparent via filling

Improved method and equipment for filling optically transparent via holes

Improved Method and Apparatus for Optically Transparent Via Filling

The technical target field of the present invention relates to a method for filling a via hole with a material and a product produced by using the method. More particularly, the present invention relates to filling very small via holes with optically transparent materials. Even more particularly, the present invention is about filling very small via holes with optically transparent materials, so that when no light is emitted, the via holes are very unobtrusive, and when light is emitted from the rear, the via holes provide very uniform and consistent The light.

It is common to provide information by projecting light through the housing. Examples include, but are not limited to: computer keyboards, which include indicator lights for functions such as "Caps Lock" or "Num Lock"; computer monitors including "on/off" lights; and automobiles, which include indicating whether heated seats are enabled Or the indicator light of whether the airbag is on; the TV with indicator light; and many other consumer electronic devices. The usual way to provide this kind of illumination is to provide projected light. When the lamp is off, the projected light is visible, and when the lamp is turned on, the projected light is bright for indication. A large number of lamps or lamp holes may defeat the purpose of designers in the industry.

One way to attempt to make a less noticeable hole is to drill a very small and tapered hole and fill the hole with a transparent material. The holes or vias can be formed using mechanical drills, lasers, electrical discharge machining, or chemical etching. The method for manufacturing optical vias is described in the pending application No. 11/742,862 "Process for Optically Transparent Via Filling", which is assigned to the assignee of the present invention. In this method, drill out The via hole is filled with a processable transparent material, the filler transparent material is solidified, and the surface is then cleaned to remove excess solidified transparent material from the exposed surface of the object. The workable material that we believe is in a plastic state, can be poured or embedded in the through hole, and the internal shape of the through hole is consistent, so as to seal the through hole. The procedure is explained in Figures 1a to 1d. In FIG. 1a, the substrate 10 has a front side or a decorative side 12 and a back side 14. The substrate 10 with a through hole 16 is filled with a transparent filler 18 and irradiated with ultraviolet (UV) radiation 20 from an ultraviolet light source 22 to Solidification filling 18. FIG. 1b shows the same substrate 10 and vias 16 filled with solidified filler 24. It should be noted that the UV radiation has penetrated and solidified the filler, which extends beyond the front side 12, which creates "fingers" 26 of the cured filler to extend the excess front side 12. In FIG. 1c, a mechanical device (for example, a blade) 28 is a finger 26 used to remove the solidified material from the front side 12 of the substrate 10. If the fingers are small enough, the fingers of the solidified material can sometimes be removed by simply wiping with a cloth. FIG. 1d shows the substrate 10 with the via holes 16 filled with the solidified material 24 after the fingers 26 are removed.

FIG. 2 shows a high-resolution optical microscopic image of the via hole 30 filled with the cured filler 32, the image is taken from the front side or the decorative side 34 of the substrate after the excessive cured filler is removed. As shown in Figure 2, this procedure leaves a cracked surface in the cured transparent material 32 on the exposed surface of the object, which makes the vias unsightly, more noticeable when they are not emitting light, and impairs the appearance of the light. All of the above are undesirable. Therefore, there is a method and device for filling the via hole with a transparent material without the need for surface cracking Requirement to improve the aesthetic appearance when the via hole emits light and when it does not emit light.

The present invention discloses an improved method for closing a via hole in a relatively thin substrate or panel with a material, and a product manufactured by the method, wherein the material allows light to pass through the transparent filler material. We believe that vias are holes formed in panels or substrates that extend from one surface to another, and are characterized by the internal volume restricted by the inner walls and planes of the vias, which extend beyond the vias penetrated s surface. We believe that the closure is to introduce material into the internal volume of the via in this way to fill the cross section of the via. It should be noted that the entire volume of the via hole may or may not be completely filled, however, it usually results in excess material extending beyond the volume of the via hole on a surface. An object of the present invention is to disclose a method and equipment for removing these excess materials in this way, so as to leave a smooth and debris-free surface, thereby providing an improved filling of the light-transmitting vias. The panel or substrate filled in this way is usually made of metal, but other materials (for example, plastic or synthetic materials) can be used. The transparent filler material is introduced into the via hole in a processable form, and then allowed to solidify or solidify into a hard optically transparent material, which is usually attached to the inner wall of the via hole to support the remainder of the via hole Location. Exemplary materials that can be used include UV-curable polymers or other polymers that can be cured by exposure to radiation, epoxy resins that can be cured by chemical reactions, or various other types of compounds, by cooling or heat application And the solidified compound, and the solidified or hardened compound by the evaporation of the liquid Things. Any of these materials can be advantageously used in the present invention.

The example light-transmitting material is the AHS-1100 developed material manufactured by 3M Company in St. Paul, Minnesota. Other light-transmitting fillers can be used to advantage, including fillers that can be solidified by methods other than UV radiation. Solidification refers to the process of transforming a transparent filler from a substantially liquid or processable state to a solid or relatively hard state. Transparent fillings can be solidified by chemical reactions, heat or other electromagnetic radiation, exposure to air, evaporation of liquids, or other methods. The specific embodiments described herein can be adapted to use these other solidification methods. For example, in the case where the filler is two epoxy resins, they will be mixed before being applied to the via and will solidify within a determined amount of time. Before the filler is completely solidified, by Mechanical or compressed gas can quickly remove the residue. It is also necessary to consider: instead of the above-mentioned materials, thermoplastic materials can form transparent fillers. In this case, the excess material must be removed before the thermoplastic material solidifies by cooling.

According to a specific embodiment of the present invention, the method includes providing a panel including at least one via hole and closing the via hole with an optically transmissive material, and then removing the optically transmissive material before it becomes solidified or hard by solidification, cooling, and liquid evaporation Excess material. Removal of excess material before solidification leaves an exposed surface of smooth and featureless transparent material, so that when not emitting light, the via is less noticeable, and when emitting light, the via provides more uniformity Lighting. Excess material can be removed by wiping the surface with a mechanical tool (for example, a blade or rubber cleaner), or by compressed air. These steps can be followed with solvent Wipe or vacuum suction or a combination of these methods to remove any remaining excess material. In addition, the light-transmitting via hole made according to the method described herein is also disclosed. For example, what is taught here is a via hole with light-transmitting properties, wherein the light-transmitting via hole in the object is filled with an optically transmissive material, and the excess optically transmissive material is at least partially Remove from the surface of the object.

The object of the present invention is to provide a method and apparatus for producing improved filled holes on the surface. FIG. 3a shows a schematic diagram of a substrate 10 having a front side (or surface) or a decorative side (or surface) 12 and a back side (or surface) 14 and a via hole 16 which is closed by a transparent filler 18. The transparent filler 18 is partially solidified using a UV light source 50 emitting UV light 52. It should be noted that the UV light is directed to the substrate at an angle close to parallel to the back side 14 of the substrate to prevent radiation from passing through the via hole and solidifying the filler portion 54 extending beyond the front surface 12. FIG. 3b shows the substrate 10 and the solidified filler 48 in the portion of the via 16. Because the part of the partially solidified filler 48 that extends beyond the front surface 12 is not solidified, a mechanical blade or a rubber cleaner 56 can be used to wipe the entire surface to remove this part from the vicinity of the via 16 Remove excess filler 58. FIG. 3c shows the substrate 10 with a partially solidified filler 48 and an excess of unsolidified filler 58 on the top surface 12 of the substrate 10. In this specific embodiment, the UV light source 60 is placed relatively perpendicular to the back surface 14, so that the UV light 62 completely passes through the partially solidified filler 48 to the top surface 12, thereby completing the solidification process. sequence. In other embodiments, the excess filler material can be removed before any solidification process is performed. FIG. 3d shows the substrate 10 with the fully solidified filler 64, which is a view after cleaning to remove the unsolidified filler remaining above the top surface 12. This cleaning can be accomplished by vacuum or solvent cleaning or other equivalent methods, and can be performed before or after the material of the via has completely solidified.

Another specific embodiment of the present invention has been explained in Figs. 4a to 4c. FIG. 4a shows a substrate 10 having a front side 12 and a back side 14 and having via holes 16. The via hole 16 is closed with a processable transparent filler 18. In FIG. 4b, the air knife 80 is used to guide the compressed air flow 82 to the top surface of the substrate 12 to remove the excess filler 58 from the vicinity of the via hole 16. In a specific embodiment of the present invention, the vacuum nozzle 86 removes the excess filler 58 from the top surface 12 until the excess filler exits the via hole. FIG. 4c shows the solidified filler 48 in the part of the via 16, which is solidified from the back surface 14 of the substrate 10 using UV radiation 62 from the UV source 60. It also needs to be considered: it can be solidified by heat, cooling, solvent evaporation, chemical reaction or other methods. After solidification, the front surface 10 can be solvent wiped to remove any remaining traces of excess filler.

FIG. 5 shows an optical micrograph of the filled via hole 30 manufactured by the present invention taken from the decorative side or the front side 34. It should be noted that the smooth appearance of the filler 90 will make the filled vias less noticeable when they do not emit light, and the appearance of the vias can be more uniformly illuminated over a wider viewing angle.

FIG. 6 shows a scanning electron micrograph of the via hole 30 taken from the front side 34 of the panel. The via hole is provided according to a specific embodiment of the present invention. It is filled with a transparent material 92, which uses a mechanical method to remove excess unsolidified filler. Although the appearance of the filled via has been greatly improved in the prior art, for example, as shown in FIG. 2, a small amount of debris and surface texture are obvious on the solidified filler. FIG. 7 shows a scanning electron micrograph of the through hole 30 with a transparent filler 94 taken from the front side 34 of the panel, which is implemented according to a specific embodiment of the present invention, which uses compressed air and vacuum to conduct the The hole removes excess filler. This photo shows that the filler 94 has no perceptible residue and no obvious surface texture.

It will also be understood that the details of the preferred embodiments may be interchanged and still be within the scope of the teachings of the present invention.

<p>10Substrate</p><p>12Decorative side</p><p>14Back side</p><p>16Through hole</p><p>18Transparent filler</p><p>20Ultraviolet radiation</p><p>22Ultraviolet light source</p><p>24solidified filling</p><p>26Finger</p><p>28Mechanical Blade</p><p>30Through hole</p><p>32cured filler</p><p>34Decorative side</p><p>48Filling</p><p>50UV light source</p><p>52UV light</p><p>54Filling</p><p>56Mechanical blade or rubber cleaner</p><p>58Filling</p><p>60UV light source</p><p>62UV light</p><p>64Filling</p><p>80Air Knife</p><p>82Air flow</p><p>86Vacuum nozzle</p><p>90Filling</p><p>92Transparent material</p><p>94Transparent filler</p>

The description here refers to the accompanying drawings, where similar component symbols refer to similar parts throughout many of the drawings.

Figures 1a, 1b, 1c, and 1d show prior art methods of solidifying and removing excess material from filled vias.

Figure 2 is an optical microscopic image of a solidified and clean filled via using the prior art method.

Figures 3a, 3b, 3c and 3d show the method of solidification and the use of mechanical tools to remove excess material from the filled vias.

Figures 4a, 4b, and 4c show the method of solidification and the use of air knife and vacuum to remove excess material from the filled vias.

Figure 5 is a filled guide implemented in accordance with a specific embodiment of the present invention Optical microscopic images of through holes.

Fig. 6 is a scanning electron micrograph of a filled via hole implemented in accordance with a specific embodiment of the present invention.

FIG. 7 is a scanning electron micrograph of a filled via hole implemented according to a specific embodiment of the present invention.