Injection molding equipment for encapsulating semiconductor die and the like

• US 5,876,765 A
• Filed: 11/09/1995
• Issued: 03/02/1999
• Est. Priority Date: 11/09/1995
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Hinterlechner, Gerhard
• Primary Examiner(s): RYAN, PATRICK J
• Application Number:
  US08/556,187
• Time in Patent Office: 1,209 Days
• Field of Search: 425/116, 425/129.1, 425/121, 425/190, 425/192 R, 425/543, 425/544, 425/549, 425/547, 425/552, 425/568, 425/570, 425/569, 425/572, 425/58, 425/DIG. 51, 425/120, 264/272.17, 264/328.8, 264/328.9
• US Class Current: 425/116
• CPC Class Codes: B29C 2045/2796 Axially movable nozzles or nozzle tips
• CPC Class Codes: B29C 45/14655 connected to or mounted on a carrier, e.g. lead frame
• CPC Class Codes: B29C 45/2701 Details not specific to hot or cold runner channels B29C45/2725 takes precedence
• CPC Class Codes: Y10S 425/051 Sprue removal

Abstract

A device for encapsulating a plurality of semiconductor die comprises a form having first and second halves such that as the first half contacts the second half the first and second halves have a plurality of cavities therein. The first and second halves each comprise a conduit therein for receiving a heated liquid. The device further comprises a runner block having a hole therein, a separate runner for each cavity, and a conduit therein for receiving a heated liquid. The runners have a rectangular cross section and a width to height ratio of at least 3:1. The device further comprises a mounting plate for mating with the runner block. The mounting plate comprises a concave recess and a hole in the mounting plate at the recess. The hole in the mounting plate passes through the mounting plate to align with the hole in the runner block such that an encapsulation material can be passed between the mounting plate and the runner block. The device further comprises a heated nozzle having a hole therethrough and a convex head wherein the concave recess is adapted to receive the convex head such that an encapsulation material can be passed between the nozzle and the mounting plate. The device further comprises a spring which urges the nozzle away from the mounting plate.

Claims

1. An injection molding device for encapsulating a plurality of semiconductor die, comprising:

a form having first and second halves such that as said first half contacts said second half said first and second halves form a plurality of cavities therein, said first and second halves forming a conduit therein for receiving a heated liquid;

a runner block having a separate runner therein for each said cavity, said runner block further having a conduit therein for receiving a heated liquid, wherein each said runner has a rectangular cross section and a width to height ratio of at least 3;

1, a height of one mm or less, and a length and width wherein said length is at least ten times said width;

a mounting plate which mates with said runner block, said mounting plate having a concave recess therein and a hole at said concave recess;

a heated nozzle having a hole therethrough and a convex head wherein said concave recess is adapted to receive said convex head wherein said convex portion of said nozzle has a thermal conductivity less than a thermal conductivity of said mounting plate;

a temperature plate which receives said nozzle and comprises conduits which receive a liquid for heating said temperature plate, said temperature plate heating said nozzle thereby;

wherein said hole in said mounting plate aligns with said hole in said nozzle such that an encapsulation material can pass between said nozzle and said hole in said mounting plate;

a spring for urging said nozzle away from said mounting plate; and

a ramming tool or plunger adapted to remove interlaced material from said hole in said nozzle.

2. The device of claim 1 wherein said length of each said runner is between about 50 and about 500 times said width of each said runner.

3. The device according to claim 2 wherein said runner block has at least first and second stellate distributors therein and at least six runners emanate from each said stellate distributor.

4. The device of claim 3 further comprising first and second nozzles, wherein said first nozzle injects encapsulation into said first distributor and said second nozzle injects encapsulation into said second distributor.

5. The device of claim 1 further comprising thermoset encapsulation in each said runner.

6. The device of claim 1 further comprising thermoplastic encapsulation in each said runner.

7. The device of claim 1 wherein said form is a cavity bar and said injection molding device further comprises a lead frame having a plurality of semiconductor dies attached thereto wherein each said cavity of said cavity bar receives one of said dies.

8. An injection molding device for encapsulating a plurality of semiconductor die, comprising:

a form having first and second halves such that as said first half contacts said second half said first and second halves form a plurality of cavities therein, said first and second halves each comprising a conduit therein for receiving a heated liquid;

a runner block having a separate runner therein for each said cavity, each said runner having a rectangular cross section and a width to height ratio of at least 3;

1, said runner block further having a conduit therein for receiving a heated liquid and a hole therein;

a mounting plate for mating with said runner block, said mounting plate comprising a concave recess and a hole therein at said recess which passes through said mounting plate to align with said hole in said runner block such that an encapsulation material can pass between said mounting plate and said runner block;

a heated nozzle having a hole therethrough and a convex ceramic-coated head wherein said concave recess is adapted to receive said convex head such that an encapsulation material can pass between said nozzle and said mounting plate;

a ramming tool or plunger adapted to remove interlaced material from said hole in said nozzle; and

a spring for urging said nozzle away from said mounting plate.

9. The device of claim 8 further comprising thermoset encapsulation in each said runner.

10. The device of claim 8 further comprising thermoplastic encapsulation in each said runner.

11. The device of claim 8 wherein said form is a cavity bar and said injection molding device further comprises a lead frame having a plurality of semiconductor dies attached thereto wherein each said cavity of said cavity bar receives one of said dies.