Manufacturing method of wb type packaging substrate

Abstract

The invention provides a production method of a WB (wire bonding) package substrate. The method comprises the following steps of producing a step unit with a lead bonding pad; laminating a combined dry film layer onto the surface, with the lead bonding pad, of the step unit, carrying out pattern transfer on the combined dry film layer so as to form the combined dry film layer with patterns on the surface, with the lead bonding pad, of the step unit; milling and slotting a semi-cured plate so as to form a window in the semi-cured plate, and collectively positioning and laminating the milled and slotted semi-cured plate, the step unit with the dry film and a top plate; executing the manufacturing flow of an outer layer PCB (printed circuit board); milling a through groove on the top plate, and controlling the depth so as to expose the combined dry film layer of the step unit; removing the combined dry film layer so as to expose the lead bonding pad; executing the finished product milling after the lead bonding pad is exposed.

Description

technical field [0001] The invention relates to the field of integrated circuit manufacturing, and more specifically, the invention relates to a method for manufacturing a WB-type packaging substrate. Background technique [0002] According to the connection method of input and output (I / O) components to the substrate, it is divided into traditional gold wire (WireBonding, WB type, also known as wire connection or wire bonding) and flip chip method (FlipChip, FC type). [0003] like figure 1 As shown, for the WB type, the I / O components on the single-chip or multi-chip 1 arranged on the wiring 4 are connected to the package substrate bonding pads (BondingPad) (such as wiring terminals) through leads 2 such as gold wires (GoldWire) 3) On the top, the chip is placed upwards, and the I / O points of the chip are around the periphery, and the number of points is generally limited. For the FC type, the gold wire method is changed to bump welding, the chip is turned upside down, a...

AI Technical Summary

Problems solved by technology

[0005] In order to increase the wiring density of the WB substrate, the substrate is usually designed as a multi-step structure. At present, there is no good manufacturing process for the stepped substrate, and low-fluidity (No-Flow, NF) prepregs are mostly used. The material (or step unit) and the prepreg are positioned and pressed together. Due to the flow characteristics of the prepreg during the high temperature and high pressure process, there will be a tendency for the glue to flow to the surface of the wire bonding pad on the step, and the glue flow is usually microscopically uneven, and some glue flow is more In some places, the overflowing glue will be put on the plate, resulting in the failure of subsequent wire bonding. In some places where there is little glue flow, a cavity will be formed under the steps; and the step position has a tendency to collapse downward during the lamination process. The manufacturing yield of this type of substrate is usually very low

[0006] The existing technology usually adopts prepreg shrinkage and compression (prepreg window size is usually larger than the size of the step groove), the substrate (or step unit) is pre-milled and the window is pre-milled, the process stability and repeatability are poor, and overflowing glue often occurs on the plate , pad contamination, voids under the steps, step collapse and a series of problems

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