Manufacturing method of filling a resin into a housing, an LED digital display and the method of making the same

• US 9,767,718 B2
• Filed: 03/03/2016
• Issued: 09/19/2017
• Est. Priority Date: 06/30/2015
• Status: Active Grant

• Current Assignee: Lite-On Technology (Lite-On Technology Corporation), Lite-On Technology Corporation
• Original Assignee: Lite-On Technology Corporation
• Inventors: Wong, Sung-Ming, Huang, Kuo-Yun, Chang, Hsun-Jen
• Primary Examiner(s): Wang, Jack K
• Application Number:
  US15/059,796
• Publication Number:
  US 20170004745A1
• Time in Patent Office: 565 Days
• Field of Search: 34081544
• CPC Class Codes: B29C 39/021 by casting in several steps
• CPC Class Codes: B29C 39/10 incorporating preformed parts or layers, e.g. casting around inserts or for coating articles coating a surface by casting in general B05D1/30, B29C39/126 takes precedence
• CPC Class Codes: G09F 9/3023 Segmented electronic displays
• CPC Class Codes: G09F 9/33 being semiconductor devices, e.g. diodes

Abstract

A manufacturing method of filling a resin into a housing includes the steps of: providing a housing that has at least one recess, with the recess having first and second spaces, and the first space being disposed above the second space; inverting the housing; injecting a fluid into the recess to fill the first space, with the fluid having a viscosity coefficient and a surface tension less than those of water; and injecting a first resin into the recess, with the first resin having a specific gravity greater than that of the fluid, such that the first resin fills the first space and the fluid fills the second space.

Claims

1. A manufacturing method of filling a resin into a housing, comprising the steps of:

providing a housing that has a normally-top surface and at least one recess that is indented inwardly from the normally-top surface, the recess having a first space and a second space, the first space being disposed above the second space, the first space being disposed adjacent to the normally-top surface;

inverting the housing so that the normally-top surface of the housing faces downwardly and the second space is disposed above the first space;

injecting a fluid into the recess to fill the first space, the fluid having a viscosity coefficient and a surface tension less than those of water; and

injecting a first resin into the recess to contact the fluid, the first resin having a specific gravity greater than that of the fluid so as to permit the first resin to sink beneath the fluid and to exchange position with the fluid, such that the first resin fills the first space and the fluid fills the second space.

2. The method of claim 1, further comprising a step of baking the fluid and the first resin so as to form a first resin layer after the step of injecting the first resin into the recess.

3. The method of claim 2, further comprising a step of injecting a second resin into the second space to fill the second space after the step of baking the fluid and the first resin.

4. The method of claim 3, further comprising a step of baking the second resin to form a second resin layer after the step of injecting the second resin into the second space.

5. The method of claim 1, wherein the fluid is a liquid having a low surface tension, the liquid being selected from the group consisting of isopropyl acetone, ethanol, and the combination thereof.

6. A method of manufacturing an LED digital display, comprising the steps of:

providing a housing that includes a normally-top surface and a surrounding surface, the normally-top surface being formed with at least one first opening, the surrounding surface extending downwardly from a periphery of the first opening and defining a recess, the recess having a first space and a second space, the first space being disposed above the second space, the first space being disposed adjacent to the normally-top surface;

attaching an adhesive tape to the normally-top surface of the housing to seal the first opening;

inverting the housing so that the normally-top surface of the housing and the adhesive tape face downwardly and the second space is disposed above the first space;

injecting a fluid into the recess to fill the first space, the fluid having a viscosity coefficient and a surface tension less than those of water;

injecting a first resin into the recess to contact the fluid, the first resin having a specific gravity greater than that of the fluid so as to permit the first resin to sink beneath the fluid and to exchange position with the fluid so that the first resin fills the first space and the fluid fills the second space;

baking the fluid and the first resin so as to form a first resin layer;

injecting a second resin into the second space;

placing a circuit board provided with a LED chip within the housing, the LED chip being disposed in the recess in such a manner that the LED chip is encapsulated by the second resin; and

baking the second resin so as to form a second resin layer.

7. The method of claim 6, wherein the recess has a second opening opposite to the first opening, the injection of the first resin into the recess being conducted by inserting a perfusion needle through the second opening into the recess at a position close to the adhesive tape.

8. The method of claim 6, wherein the fluid is a liquid having a low surface tension, the liquid being selected from the group consisting of isopropyl acetone, ethanol, and the combination thereof.

9. An LED digital display comprising:

a circuit board;

an LED chip provided on said circuit board;

a housing having a normally-top surface and a surrounding surface, said normally-top surface being formed with at least one first opening, said surrounding surface extending downwardly from a periphery of said first opening and defining a recess, said recess having a first space and a second space, said first space being disposed above said second space, said first space being disposed adjacent to said normally-top surface;

a first resin layer containing a first resin and a fluid and disposed in said first space; and

a second resin layer containing a second resin and filling said second space so as to encapsulate said LED chip.

10. The LED digital display of claim 9, wherein at least one of said first and second resins is made from a material comprising epoxy resin, said fluid comprising isopropyl acetone or ethanol.

11. The LED digital display of claim 9, wherein said housing is a reflector of a 7-segment digital display, and said normally-top surface has seven first openings, said housing further has seven surrounding surfaces, each extending downwardly from a periphery of a corresponding one of said seven first openings.

12. The LED digital display of claim 9, wherein said surrounding surface defines a second opening opposite to said first opening, said circuit board being disposed in the housing, covering said second opening, and being embedded in said second resin layer.

13. The LED digital display of claim 12, wherein said LED chip is mounted on one side of said circuit board and is disposed adjacent to said second opening, said circuit board being provided with at least one conductive pin extending from the other side of said circuit board in a direction away from said circuit board.

14. The LED digital display of claim 9, wherein said fluid has a surface tension ranging from 0.0023 N/m to 0.077 N/m.