We started a technical blog.

We would like to introduce a concrete example using Ings Shinano's technology.

However, we are basically a contract processor, and the products we work on every day are confidential to our customers, so we cannot introduce them as they are.
Therefore, we would like to introduce the exhibition samples made for the exhibition and the processing performed for internal evaluation to the extent that they can be disclosed.

First of all, we will introduce the lighting board used for the mini LED exhibition and an example of mounting the mini LED.

The following is an explanation of the exhibits.

---

There is a sample in which RGB individual LEDs are arranged to form a matrix, and a sample in which Blue LEDs are arranged at a pitch of 0.2 mm.

The LEDs installed in both are 0.2 x 0.1 mm size (0201MM) mini LEDs. The small capacitor and resistor chip parts are 0.4 x 0.2 mm (0402MM), which is 1/4 the size, so you can see how small they are.

You can't pinch it with ordinary tweezers, and if you drop it somewhere, you can't find it. Even with chip capacitors, 0603 size requires some getting used to soldering by hand, but 0201 size is probably not possible.


By the way, as I mentioned earlier, we are a company that provides implementation services.

We have made it possible to bond mini LEDs by introducing a bonder that supports mini LEDs, but how to use this is basically up to the customer. We don't have much know-how to turn on LEDs in the company, so we have been thinking about ways to appeal how to use mini LEDs by groping.

First, the RGB matrix.
When we realized that we could get three types of LED emission colors, R, G, and B, the idea of "let's shine the three colors of RGB" came up immediately.

The problem is how to make it shine.

At best, it was at the level of attaching a current limiting resistor and turning it on individually, and wondering if matrix operation could be performed with a microcomputer + shift register, but the mini LED is small. There was also a desire to turn on as many lights as possible, so we continued to research various ways to turn them on.

We found an LED drive IC there. It was an IC that could control 18x11 matrix LEDs with one chip.

(Continued to Part 2)

---

Bonding the driver IC on the glass panel

COG is an abbreviation for Chip On Glass, which is a bonding method in which a flip chip is bonded on a glass substrate by thermal crimping with ACF.

The mainstream method is to bond the driver IC required to drive a flat panel display such as an LCD directly on the panel. This is COG bonding, and in addition to this, in order to realize a narrow frame display, driver bonding is done on the FPC (COF), and a structure that narrows the total frame by pinching pitch FOG has also been adopted.
Due to the improvement of LCD resolution / definition, driver ICs are becoming more and more pinned and pitched, and the shape of the IC is becoming more elongated.

We have many years of experience in supporting COG, and we can handle various COG bonding.

---

What is a mini LED?

We've come to see news about mini LEDs and micro LEDs a lot.
There seems to be no clear definition, but a mini LED refers to a bare chip LED with a size of about □ 0.1 mm, and an LED with a size of several μm to several tens of μm smaller than that is called a micro LED. It seems that there are many cases.

Since the mini LED is a bare chip, it can save a lot of space and height compared to the packaged product (bullet type or packaged for SMT).
There are exceptions, but basically it is a single color LED for bare chips, and we can make various colors emit light by arranging RGB chips, or we can spread LEDs of the same color to make surface emission.
In addition, the small chip size minimizes the presence when not lit.

It seems that product development is being carried out for various applications by taking advantage of these characteristics.

Mini LED bonding technology

---

About prototype

---

The mini LED is a bare chip LED with a size of about 0.1 to 0.2 mm, which is an unprecedented device, and after receiving a consultation as to whether it can be applied to various products, we actually make prototypes and help with basic evaluation.

Please feel free to contact us regarding prototypes, experiments, and evaluations of products that use mini LEDs.

---

---

In the case of COB (Chip on Board), there are various connection methods such as wire bonding and ACF connection even if it is called COB, but COF seems to refer to bonding by ACF connection. (It is possible to perform wire bonding on FPC, but since there are not many examples, COF is usually chip bonding on FPC by ACF.)

Since it is an ACF connection, the chip and FPC are electrically connected, and at the same time, they are mechanically fixed.
Of course, since it is on a flexible FPC, if stress is applied, the FPC will come off or the IC will crack. Therefore, it is necessary to be careful when handling it by the customer after bonding.

Most of the COFs are used to bond driver ICs for displays. Since an IC with a very large number of terminals will be bonded, the FPC may have a wiring pitch of 30 to 40 um. The IC is bonded on such a fine pitch FPC with high accuracy.

Ings Shinano flexibly supports COF bonding from several prototypes to mass production in small quantities. Please feel free to contact us from the inquiry page.

---

---

The bonding method is thermocompression bonding (ACF crimping) using ACF.
Normally, FPCs with a terminal pitch of 80 to 200 μm are often bonded, but we have introduced a high-precision FOG bonding machine that can support bonding with a pitch of 26 μm, and are bonding various FOGs.
For pinch pitch bonding such as 26 μm, it is necessary not only to support the machine capacity of the bonding machine, but also to support FPC design and material management.

We also have various types of experience with ACF materials used for ACF crimping. ACF bonding that meets the conditions recommended by the ACF manufacturer can be performed.
We also support a wide range of FPC sizes that can be bonded, so please contact us if you have any problems with ACF crimping.

---