Semiconductor device package and method of manufacture
View Patent ↗A structure and method to improve saw singulation quality and wettability of integrated circuit packages ( 140 ) assembled with lead frames ( 112 ) having half-etched recesses ( 134 ) in leads. A method of manufacturing lead frames includes providing a lead frame strip ( 110 ) having a plurality of lead frames. Each of the lead frames includes a depression ( 130 ) that is at least partially filled with a material ( 400 ) prior to singulating the lead frame strip.
1. A method of manufacture, comprising:
providing lead frame strip that includes a plurality of lead frames each of which includes:
an outer frame structure defining a central opening,
a die pad disposed within the central opening, and
a plurality of leads attached to the outer frame structure and extending inward toward the die pad in spaced relation to each other, wherein each lead of one lead frame extends outward from its die pad and is integral with a lead that extends outward from a die pad of an adjacent lead frame;
creating an elongated depression in the lead frame strip, the elongated depression having a middle portion and two end portions, each of the two end portions becoming, after singulating of the lead frame strip into individual lead frames, a recess at a corner of an end of a lead; and
filling the elongated depression with a material prior to singulating of the lead frame strip into individual lead frames.
2. The method of manufacture of claim 1 , including a step of encapsulating the lead frame strip with a mold compound.
3. The method of manufacture of claim 1 , including a step of singulating the lead frame strip into individual lead frames.
4. The method of manufacture of claim 3 , wherein the material is a solder wettable material.
5. The method of manufacture of claim 3 , including a step of removing the material from the individual lead frames after the step of singulating.
6. The method of manufacture of claim 4 , wherein the material remains in the elongated depression after the step of singulating.
7. The method of manufacture of claim 1 , in which the material is a material from a group consisting of: an adhesive material, a thermoplastic material and a polymer material.
8. The method of manufacture of claim 1 , wherein the material is soluble in water that is above room temperature.
9. The method of manufacture of claim 8 , in which the material is a thermosetting polymer material.
10. The method of manufacture of claim 1 , in which the material is polyimide, and including a step of removing the polyimide, using acetone, after the step of singulating.