CN-122028744-A - High-density ultrathin lead frame packaging technology and packaging structure

Abstract

The invention discloses a high-density ultrathin lead frame packaging process and a packaging structure, and belongs to the technical field of semiconductor packaging. The process comprises the steps of lead frame manufacturing (forming ultra-thin circuits with the thickness of less than or equal to 30 mu m by photoetching the front surface of a copper foil, back surface silver plating), component mounting and welding, front surface plastic package curing, back surface circuit etching, back surface insulation protection and electrode metal protection layer manufacturing, and adopting an ultra-thin substrate with the thickness of less than or equal to 40 mu m. The cost is reduced by single-sided etching without a film, the back side is etched after plastic packaging to realize an ultrathin structure, the design of a suspension circuit improves the flexibility, and the suspension circuit is compatible with various packaging forms such as LGA, PGA and the like. The prepared lead frame has the characteristics of high density and ultra-thin, can solve the problems of low density, large thickness and high cost of the traditional process, is suitable for miniaturized and high-integration electronic equipment, and has remarkable economic benefit and application value.

Inventors

• ZHANG QIN

Assignees

• 中山思睿科技有限公司

Dates

Publication Date

20260512

Application Date

20251209

Claims (4)

1. 1. The high-density ultrathin lead frame packaging process is characterized by comprising the following steps of: preparing a base material; manufacturing a front circuit on the front side of the substrate by using an etching process; Mounting the components on the front circuit through a welding process; Manufacturing a plastic sealing layer on the front surface of the base material; Manufacturing a back circuit on the back of the substrate by using an etching process, wherein the back circuit is communicated with the front circuit; And manufacturing a protective layer on the back of the substrate.
2. 2. The high-density ultra-thin lead frame packaging process of claim 1, wherein the back side of the substrate is silver plated prior to the pair of electronic devices being mounted to the front side circuitry by a soldering process.
3. 3. The high-density ultra-thin lead frame packaging process of claim 1, wherein the substrate is copper foil.
4. 4. A high-density ultra-thin lead frame packaging structure, characterized in that it is made by the high-density ultra-thin lead frame packaging process according to any one of claims 1-3, and the circuit pitch in the front circuit is less than 30 μm, and the thickness of the lead frame is less than 40 μm.

Description

High-density ultrathin lead frame packaging technology and packaging structure Technical Field The invention relates to the technical field of semiconductor packaging technology, in particular to a high-density ultrathin lead frame packaging technology and a packaging structure. Background In the field of semiconductor packaging, with the continuous development of miniaturization and multifunction of electronic equipment, higher and higher requirements are put on a lead frame and a packaging process thereof. Conventional lead frames have significant shortcomings in terms of density. With the continuous improvement of chip integration, the number of pins to be connected is increased, and the requirement on the line spacing of the lead frame is more and more strict. However, the conventional manufacturing process is difficult to realize ultra-fine pitch circuits, and the common circuit pitch is often larger, so that the increasingly high-density connection requirement cannot be met. For example, in some high-end chip packages, the lead frame wire pitch is too large, limiting the overall miniaturized design of the chip, making it difficult to further shrink the product in size, affecting its application in miniaturized electronic devices. In terms of thickness, the thickness of the chip after the packaging of the traditional lead frame is larger. This is because the conventional packaging method cannot effectively optimize the combined structure of the lead frame and the carrier, and the overall thickness cannot meet the requirements of the miniaturized device for light and thin. For example, in products that are extremely space sensitive, such as wearable devices, smart phones, etc., a chip of greater thickness not only occupies more space, but may also affect the design and wearing comfort of the device. Cost is also an important issue faced by conventional lead frame and packaging processes. The conventional process generally requires double-sided etching of the lead frame and the use of a film during etching, which not only increases the production cost but also makes the packaging process complicated and tedious. The complex process not only requires more equipment and labor investment, but also is easy to introduce more errors in the production process, and the production efficiency is reduced. In summary, the existing lead frame and packaging process have many defects in terms of density, thickness, cost and the like, and cannot well adapt to the requirements of rapid development of modern electronic devices, and a new technical scheme is urgently needed to solve the problems. Therefore, a new package form of high-density input-output terminals is demanded, which has higher integration while ensuring reliability. Disclosure of Invention Accordingly, in order to solve the above-mentioned problems, an object of the present invention is to provide a high-density ultra-thin lead frame packaging process, comprising the steps of: preparing a base material; manufacturing a front circuit on the front side of the substrate by using an etching process; the components are attached to the front circuit through a welding process, and the welding mode can be selected from reflow soldering and hot-press soldering, and also can use a die bonding and bonding process; Manufacturing a plastic sealing layer on the front surface of the base material; Manufacturing a back circuit on the back of the substrate by using an etching process, wherein the back circuit is communicated with the front circuit; And manufacturing a protective layer on the back of the substrate. Preferably, the back side of the substrate is partially silver plated before the pair is soldered to the front side circuitry. Preferably, the substrate is copper foil. A high-density ultrathin lead frame packaging structure is manufactured by the method. The beneficial effects of the invention are as follows: The invention provides a packaging structure based on a high-density ultrathin lead frame, which is manufactured through the technical processes of manufacturing the lead frame, device mounting, bonding, plastic packaging, back etching and the like. The chip package is not limited by the size of a wafer, so that each terminal is uniformly distributed, high-reliability connection can be realized, and the chip package with high density, ultra-thin, high reliability and low cost can be realized, so that the chip package is suitable for the requirements of modern equipment on light weight, miniaturization and high integration level. Drawings In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort